See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/278696184
Elbow Anatomy
Chapter · January 2014
DOI: 10.1007/978-3-642-36801-1_38-1
CITATION
READS
1
1,858
4 authors:
Francesc Malagelada
Miki Dalmau-Pastor
Barts Health NHS Trust
University of Barcelona
23 PUBLICATIONS 162 CITATIONS
13 PUBLICATIONS 11 CITATIONS
SEE PROFILE
SEE PROFILE
Jordi Vega
Pau Golano
University of Barcelona and Hospital Quiron
University of Barcelona
52 PUBLICATIONS 488 CITATIONS
82 PUBLICATIONS 1,293 CITATIONS
SEE PROFILE
SEE PROFILE
All content following this page was uploaded by Miki Dalmau-Pastor on 09 July 2015.
The user has requested enhancement of the downloaded file. All in-text references underlined in blue are added to the original document
and are linked to publications on ResearchGate, letting you access and read them immediately.
Sports Injuries
DOI 10.1007/978-3-642-36801-1_38-1
# Springer-Verlag Berlin Heidelberg 2014
Elbow Anatomy
Francesc Malageladaa, Miquel Dalmau-Pastorb, Jordi Vegac and Pau Golanób,d*
a
Barts and The London NHS Trust, London, UK
b
Department of Pathology and Experimental Therapeutics (Human Anatomy Unit), University of Barcelona, Laboratory
of Arthroscopic and Surgical Anatomy, L’Hospitalet de Llobregat, Barcelona, Spain
c
Hospital Quiron, Barcelona, Spain
d
Department of Orthopaedic Surgery, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
Abstract
The elbow is a complex joint that consists of three different articulations: humeroulnar,
humeroradial, and proximal radioulnar. During certain activities it can be subjected to significant
loads, especially in racquet or throwing sports. The ligamentous complexes of the elbow are
involved in the pathoanatomy of throwing athletes or in elbow dislocations and instability. The
elbow is crossed by important nerves and vessels for the function of the upper extremity and is the
origin of the flexor–pronator and extensor–supinator musculatures of the forearm. A sound knowledge of the elbow anatomy is essential to diagnose and treat elbow sports injuries.
The aim of this chapter is to present a review of the elbow anatomy to assist the surgeon or sports
medicine physician in the diagnosis and treatment of the athletic population.
Introduction
The elbow is a complex joint consisting of three articulations: the humeroulnar, the humeroradial,
and the proximal radioulnar joints. Although it is not a weight-bearing joint, it can be subjected to
high loads when practicing racket or throwing sports, or in gymnastics. As a consequence of these
continued sport activities, stability structures of the elbow can result affected. Elbow stability is
provided by static and dynamic constraints. Static constraints or passive elbow stabilizers include
the osteoarticular anatomy, the medial and lateral collateral ligament complexes, and the capsule.
Dynamic constraints or active elbow stabilizers are the muscles that cross the elbow joint.
A thorough knowledge of the anatomy is essential to diagnose and treat any conditions in the
elbow. Along with the necessary skills, anatomy is the key to consistent results in open and
arthroscopic surgery. The aim of this chapter is to provide the surgeon or sports medicine physician
with a visual review of the elbow anatomy.
Surface Anatomy
The elbow is a superficial joint, and therefore, many anatomical landmarks can be palpated around
its surface. Understanding of surface anatomy is necessary to perform an effective physical
Pau Golano has deceased
*Email: paugolano@gmail.com
*Email: pgolano@ub.edu
Page 1 of 30
Sports Injuries
DOI 10.1007/978-3-642-36801-1_38-1
# Springer-Verlag Berlin Heidelberg 2014
examination and in surgical and nonsurgical management. Prior to arthroscopic portal placement,
some of these landmarks should be marked, including the ulnar nerve (Byram et al. 2013).
In anatomical position (extension and supination of the elbow), the cubital fossa and its boundaries are easily observed in the anterior area. The brachioradialis muscle forms the lateral border,
whereas the medial is formed by the pronator teres muscle distally and the tendon of the biceps
brachii muscle proximally (Fig. 1). When the forearm is supinated, the radial tuberosity is palpable at
the insertion of the biceps brachii tendon. A change in muscle contour, or proximal retraction of the
muscle, may indicate a distal biceps brachii tendon rupture (Hsu et al. 2012). The median nerve is
also palpable when flexing the elbow and sliding a finger underneath the distal biceps brachii tendon.
It is felt as a cord-like structure. Next to it the pulse of the brachial artery is evident as they follow the
same course together. The flexor–pronator musculature is palpable emerging from its origin at the
medial epicondyle. Both the cephalic vein laterally and the basilic vein medially are usually visible
in athletic subjects.
Posteriorly, the olecranon is easily localized at the center of the joint. When the elbow is at 90 of
flexion, the medial and lateral epicondyles form an inverted triangle with the olecranon (Fig. 2). On
Fig. 1 Anatomical dissection of the cubital fossa and its boundaries. 1 Biceps brachii muscle, 2 biceps brachii tendon,
3 lacertus fibrosus, 4 brachialis muscle, 5 brachioradialis muscle, 6 extensor carpi radialis longus, 7 extensor carpi
radialis brevis, 8 pronator teres, 9 flexor carpi radialis, 10 palmaris longus 11 flexor carpi ulnaris, 12 musculocutaneous
nerve, 13 communicating venous branch (cut) between the superficial veins and humeral veins, 14 median nerve, 15
humeral artery. # Pau Golano
Page 2 of 30
Sports Injuries
DOI 10.1007/978-3-642-36801-1_38-1
# Springer-Verlag Berlin Heidelberg 2014
Fig. 2 Elbow viewed from posterior. (a) With the elbow extended, the medial and lateral epicondyles and the tip of the
olecranon are alienated. (b) With the elbow flexed to 90 , these three bony landmarks form an equilateral triangle. The
relationship between these three bony landmarks is altered with displaced intra-articular distal humerus fractures or
during elbow dislocations. # Pau Golano
the medial aspect of the elbow, the ulnar nerve can be palpated distal to the medial epicondyle at the
level of its groove. It should also be checked for mobility since it can become subluxated during
flexion of the elbow and reduced in extension (Novak et al. 2012). On the lateral aspect, the lateral
epicondyle and the extensor–supinator musculature are palpable. Another group of muscles, the
mobile wad of three (Henry 1970) (brachioradialis, extensor carpi radialis brevis, and extensor carpi
radialis longus), are located anterior to the extensor–supinator mass. At a distance of 2 cm distally
from the lateral epicondyle, the humeroradial joint and the radial head are felt especially when
pronosupinating the forearm.
A posterolateral soft spot formed between the lateral epicondyle, the olecranon, and the radial
head is a landmark for placement of the direct lateral arthroscopic portal. Through this portal
irrigation fluid is introduced into the joint to distend the anterior compartment and create a safe
anterior working area for arthroscopy. Furthermore, this posterior soft spot should be palpated for
fullness, indicating elbow joint effusion or hemarthrosis (Hsu et al. 2012) (Fig. 3). Other commonly
used portals during elbow arthroscopy are summarized in Table 1 with distances to anatomic
landmarks and structures at risk (Rosenberg and Loebenberg 2007).
Osteology
The elbow can be simplified to a hinge joint (ginglymus) between the distal humerus and proximal
ulna and radius (Fig. 4). In reality, it consists of three different joints: the humeroulnar and the
Page 3 of 30
Sports Injuries
DOI 10.1007/978-3-642-36801-1_38-1
# Springer-Verlag Berlin Heidelberg 2014
Fig. 3 (a) Lateral view of the elbow showing the surface anatomy of the soft spot formed between the lateral
epicondyle, the olecranon, and the radial head. (b) Anatomical dissection showing the relationship of the soft spot
and the wrist extensors muscle group. 1 Biceps brachii muscle, 2 brachialis muscle, 3 triceps brachii muscle, 4 lateral
intermuscular septum, 5 brachioradialis muscle, 6 extensor carpi radialis longus muscle, 7 extensor carpi radialis brevis
muscle, 8 extensor digitorum muscle, 9 anconeus muscle, 10 extensor digiti minimi. # Pau Golano
humeroradial (ginglymoid motion in flexion and extension) and the proximal radioulnar joint
(trochoid motion in pronation and supination). Combined these articulations create a trochleoginglymoid joint (Prasad et al. 2003). This configuration makes the elbow fairly constrained and
one of the most congruous and stable joints of the body (Fig. 5). The ulna and the radius are
connected by the forearm interosseous membrane which highly contributes to the stability of the
proximal and distal radioulnar joints.
The normal range of motion of the elbow is approximately 0 of extension and 140 of flexion.
A functional range of motion for activities of the daily living has been described to be of 30–130 ,
and the functional arc of throwing ranges from 20 to 130 . The normal supination and pronation are
both of approximately 80 (Morrey et al. 1981) (Fig. 6).
The distal humeral shaft widens to constitute the triangular shape of the epiphysis. The medial and
lateral supracondylar columns transition to the medial and lateral epicondyles and terminate at the
two humeral condyles with their articular surfaces. The outermost aspect of these columns comprises the medial and lateral supracondylar ridges, respectively. The medial condyle has the spoolshaped trochlea which articulates with the proximal ulna and is covered by articular cartilage over an
arc of 300 . The more prominent medial epicondyle is an attachment point for the ulnar collateral
ligament complex and the flexor–pronator musculature. The lateral condyle has the hemisphericshaped capitulum which articulates with the radial head (Miyasaka 1999; Morrey and An 2000).
Lateral and proximal to the capitulum is the lateral epicondyle, an origin point for the lateral
collateral ligament complex and the supinator–extensor musculature (Fig. 7).
Just proximal to the condyles, there are three fossas that are uncovered of articular cartilage but
play an important role in the range of movement. Anteriorly, the coronoid and radial fossa
accommodate the coronoid process of the ulna and radial head, respectively, during elbow flexion
Page 4 of 30
Sports Injuries
DOI 10.1007/978-3-642-36801-1_38-1
# Springer-Verlag Berlin Heidelberg 2014
Table 1 Elbow arthroscopic portals. + Distances showed in mm correspond to the average distance. Note that portals
are safer when the elbow is flexed
Portal
Purpose
Direct lateral Distension/viewing
Proximal
medial
Working/high flow
irrigation
Anterolateral Viewing
Preference to the safer
proximal lateral
Proximal
lateral
Viewing
Anteromedial Viewing
Posterolateral Viewing
Straight
posterior
Working (removal of
posterior osteophytes or
synovectomy)
Location
Soft spot (triangle between olecranon, radial
head, and lateral epicondyle)
2 cm proximal to medial epicondyle.
Slightly anterior to the intermuscular septum
Structures at risk +
Posterior antebrachial
cutaneous nerve
Median nerve (12.4 mm
distended/7.6 mm non
distended)
Ulnar nerve (12 mm)
Medial antebrachial
cutaneous nerve (6 mm at
90 flexion)
1 cm distal and 1 cm anterior to lateral
Radial nerve (3 mm at 90
epicondyle. In a sulcus between radial head flexion)
and capitulum
Posterior antebrachial
cutaneous nerve (2 mm at
90 flexion)
2 cm proximal and 1 cm anterior to the
Lateral antebrachial
lateral epicondyle
cutaneous nerve (6.1 mm)
Radial nerve (9.9 mm at
90 /4.9 mm in extension)
2 cm anterior and 2 cm distal to the medial Medial antebrachial
epicondyle
cutaneous nerve (1 mm)
Median nerve (7 mm
flexed/2 mm extended)
3 cm proximal to olecranon, superior and
Medial and posterior
posterior to the lateral epicondyle
antebrachial cutaneous
nerves (25 mm)
3 cm medial to the posterolateral portal
Posterior antebrachial
cutaneous nerve (23 mm)
Ulnar nerve (25 mm)
(Fig. 7). Posteriorly, the olecranon fossa accommodates the olecranon in full elbow extension. If an
occupying lesion is present in these areas, flexion and extension of the elbow will be reduced.
The humeral trochlea articulates with the ulnar notch (or incisura semilunaris) of the proximal
ulna. This notch opens at an angle of 30 posteriorly with respect to the long axis of the ulna. The
medial ridge of the trochlea is more prominent than the lateral ridge, causing a valgus tilt of 6–8 at
the articulation (Miyasaka 1999). The capitulum articulates with the concave surface of the radial
head, whereas the rim of the radial head articulates with the radial notch. These articular condyles are
angulated 30 anteriorly in relation to the humeral axis, complementing the 30 posterior angle of the
ulnar notch to allow full extension (Fig. 7). The carrying angle is defined by the angle between the
long axis of the humerus and ulna measured in full extension. This averages 11–14 in males and
13–16 in females. This valgus angle is commonly greater than 15 in throwing athletes (King
et al. 1969; Morrey and An 2000).
The proximal radius includes the cylindrical radial head and neck (Figs. 8 and 9). The radial head
articulates with both the radial notch of the ulna and the humerus at the capitulum and at the
trochleocapitellar groove. Articular cartilage covers the concave surface of the radial head and an arc
of 280 of the rim. This leaves the remaining 80 of the anterolateral rim devoid of cartilage. The
radial neck length is of 13 mm (range 9–19mm). The radial head is angulated 55 (range 45–65º).
Page 5 of 30
Sports Injuries
DOI 10.1007/978-3-642-36801-1_38-1
# Springer-Verlag Berlin Heidelberg 2014
Fig. 4 Anterior view of the elbow bones and its joints: humeroulnar, the humeroradial, and the proximal radioulnar
joints. The bones have been colored digitally with Adobe Photoshop. With red color the humerus, with blue color the
radius, and with green color, the ulna. # Pau Golano
Fig. 5 Elbow bones and its joints showing the most important anatomical details. (a) Anterior view, (b) posterior view.
1 Humeral diaphysis, 2 lateral supracondylar ridge, 3 medial supracondylar ridge, 4 radial fossa, 5 coronoid fossa,
6 olecranon fossa, 7 lateral epicondyle, 8 medial epicondyle, 9 capitulum, 10 trochlea, 11 trochleocapitellar groove, 12
radial diaphysis, 13 radial head, 14 radial neck, 15 radial tuberosity, 16 ulnar diaphysis, 17 coronoid process, 18
olecranon, 19 ulnar tuberosity. # Pau Golano
This radial torsion is calculated by comparing a line drawn on the radial head, perpendicular to the
radial notch, to a line drawn between the center of the radial styloid process and the center of the
ulnar notch. Likewise the radial head is angulated when compared to the diaphysis as shown by a
proximal diaphysis–neck angle of 17 (range 6–28º). These considerations are important when
Page 6 of 30
Sports Injuries
DOI 10.1007/978-3-642-36801-1_38-1
# Springer-Verlag Berlin Heidelberg 2014
Fig. 6 Range of motion of the elbow joint. (a) Flexion–extension movement, provided by the humeroulnar and the
humeroradial (ginglymoid). (b) Pronation–supination movement, provided by proximal radioulnar joint (trochoid). #
Pau Golano
restoring radial anatomy in cases of radial head fractures or prosthetic replacements (Van Riet
et al. 2004). The radial neck connects the radial head to the shaft. At the medial and distal aspect of
the neck, the radial tuberosity can be found; it is a bony prominence that serves as the insertion point
of the biceps tendon.
The proximal ulna consists of the olecranon and the ellipsoid anterior surface of the ulnar notch.
The notch is covered by articular cartilage except for the mid portion which is usually covered by
fatty tissue. The olecranon is the insertion site for the triceps brachii muscle tendon. The distal end of
the ulnar notch is the coronoid process which is the insertion site for the brachialis muscle tendon
and the anterior bundle of the medial collateral ligament. At the medial aspect of the coronoid
process, the sublime tubercle is a bony prominence that serves as the insertion site for the medial
collateral ligament. At the lateral aspect of the coronoid process, the supinator crest is a rather
elongated bony prominence that serves as the attachment for the lateral ulnar collateral ligament
(Timmerman and Andrews 1994; Morrey and An 2000) (Fig. 10). It has been stated that the coronoid
process is an important restraint for elbow stability.
Capsule
The joint capsule surrounds all three articulations of the elbow joint. The anterior and posterior
portions are thinner than the medial and lateral thickenings, which form the collateral ligamentous
complexes (Reichel and Morales 2013). The anterior capsule becomes taut in extension, whereas the
posterior capsule is taut in flexion (King et al. 1993). It provides most of its stabilizing effects when
the elbow is extended (Deutch et al. 2003) (Fig. 11).
The capacity of the normal capsular elbow joint has been estimated to be just over 20 ml (Fig. 12).
It has been described to be greater in cases of chronic instability and decreased in the presence of
joint contractures (O’Driscoll et al. 1990). The maximum volume capacity of the capsule is of
Page 7 of 30
Sports Injuries
DOI 10.1007/978-3-642-36801-1_38-1
# Springer-Verlag Berlin Heidelberg 2014
Fig. 7 Humerus bone. (a) Anterior view, (b) posterior view, (c) lateral view, (d) medial view. 1 Humeral diaphysis,
2 lateral supracondylar ridge, 3 medial supracondylar ridge, 4 radial fossa, 5 coronoid fossa, 6 olecranon fossa, 7 lateral
epicondyle, 8 medial epicondyle, 9 capitulum, 10 trochlea, 11 trochleocapitellar groove, 12 sulcus for ulnar nerve.
# Pau Golano
25–30 ml in adults occurring at 80 of flexion (Alcid et al. 2004). This enables to predict the position
of greatest comfort when effusion or hemarthroses are present.
Gray and Morrey in their anatomic studies provided detailed description of the elbow capsule
(Gray 1918; Morrey and An 2000). The anterior capsule inserts proximally above the coronoid and
radial fossas. Distally it is attached to the anterior margin of the coronoid process medially and to the
annular ligament laterally. Fibrous bands have been described within the capsule: three anteriorly
and three distinct bands posteriorly. Anteriorly, they have been termed according to its location as
anterior lateral, anterior medial oblique, and anterior transverse bands. The posterior capsule inserts
proximally above the olecranon fossa, and distally at the annular ligament and the tip of the
olecranon. Most of the olecranon is therefore an extracapsular structure. The three capsular bands
described posteriorly are the posterior lateral oblique, posterior medial oblique, and posterior
Page 8 of 30
Sports Injuries
DOI 10.1007/978-3-642-36801-1_38-1
# Springer-Verlag Berlin Heidelberg 2014
Fig. 8 Radius bone. (a) Anterior view, (b) posterior view. 1 Radial diaphysis, 2 radial head, 3 radial neck, 4 radial
tuberosity. # Pau Golano
Fig. 9 Anterior view of the proximal radioulnar joint. 1 Ulnar diaphysis, 2 olecranon, 3 tip of the olecranon, 4 coronoid
process, 5 tip of the coronoid process, 6 ulnar notch, 7 the ulnar notch is divided by a transverse portion composed of
fatty tissue into a anterior portion made up of the coronoid process and the posterior olecranon, 8 sublime tubercle,
9 radial notch, 10 ulnar tuberosity, 11 radial diaphysis, 12 radial head, 13 radial neck, 14 radial tuberosity, 15 typical
osteochondral lesion of the radial head at the level of trochleocapitellar groove. # Pau Golano
Page 9 of 30
Sports Injuries
DOI 10.1007/978-3-642-36801-1_38-1
# Springer-Verlag Berlin Heidelberg 2014
Fig. 10 Ulna bone. (a) Anterior. (b) Lateral view. (c) Posterior view. (d) Medial view. 1 ulnar diaphysis, 2 olecranon,
3 tip of the olecranon, 4 coronoid process, 5 tip of the coronoid process, 6 ulnar notch, 7 the ulnar notch is divided by a
transverse portion composed of fatty tissue into a anterior portion made up of the coronoid process and the posterior
olecranon, 8 radial notch, 9 ulnar tuberosity, 10 supinator crest, 11 sublime tubercle. # Pau Golano
transverse bands. They are considered to reinforce the capsule (Reichel and Morales 2013) (Figs. 11
and 12).
On the inner aspect of the capsule, some synovial folds can be distinguished. Specially consistent
are two lateral folds, one under the annular ligament and a second one between the head of the radius
and capitulum which adopts a meniscoid structure and may assist in humeroradial joint motion
(Bozkurt et al. 2005; Sanal et al. 2009) (Fig. 13).
Ligaments
The medial and lateral collateral ligament complexes are primary elbow stabilizers (Bryce and
Armstrong 2008). The classical anatomy described below is found in the majority of cases but
Page 10 of 30
Sports Injuries
DOI 10.1007/978-3-642-36801-1_38-1
# Springer-Verlag Berlin Heidelberg 2014
Fig. 11 (a) Anterior view of the elbow joint capsule. (b) Posterior view of the elbow joint capsule (elbow in extension). (c)
Posterior view of the elbow joint capsule (elbow in 90 of flexion).1 Lateral epicondyle, 2 medial epicondyle, 3 synovial
recess under the annular ligament, 4 biceps brachii tendon (cut) at the level of its insertion in the radial
tuberosity, 5 olecranon, 6 lateral collateral ligament, 7 annular ligament, 8 medial collateral ligament, 9 coronoid process.
# Pau Golano
Fig. 12 Anterior view of the elbow joint capsule. The synovial space was filled with blue latex. 1 Medial epicondyle,
2 lateral epicondyle, 3 synovial recess under the annular ligament, 4 radial tuberosity, 5 biceps brachii tendon (cut) at
the level of its insertion in the radial tuberosity, 6 coronoid process, 7 anterior medial oblique fibrous band, 8 anterior
transverse band, 9 lateral collateral ligament, 10 annular ligament, 11 medial collateral ligament, 12 subsynovial fat pads.
# Pau Golano
Page 11 of 30
Sports Injuries
DOI 10.1007/978-3-642-36801-1_38-1
# Springer-Verlag Berlin Heidelberg 2014
Fig. 13 Sagittal section of the elbow at the level of the humeroradial joint. 1 Capitulum, 2 radial head, 3 radial neck,
4 synovial fold which adopts a meniscoid structure. # Pau Golano
variations have been described in the anatomy of both the medial and lateral collateral ligament
complexes (Beckett et al. 2000).
Medial Collateral Ligament Complex
The medial collateral ligament complex (MCL) consists of three bundles with different points of
origin and insertion forming a triangular shape: the anterior, posterior, and transverse (Fig. 14).
Because of the multiplicity of the bundles and their functions, the MCL has been compared to the
anterior cruciate ligament of the knee (Fuss 1991). The anterior bundle (or anterior oblique ligament)
is the most significant component of the MCL, being the main stabilizer to valgus stress of the elbow
(Morrey and An 1985; Regan et al. 1991; Callaway et al. 1997; Miyake et al. 2012). Its origin is at
5 mm anterior and inferior to the tip of the medial epicondyle and inserts on the sublime tubercle,
18 mm distal to the coronoid tip, along the medial aspect of the coronoid process (Cage et al. 1995;
Callaway et al. 1997; Ochi et al. 1999). The width at its midpoint averages 5 mm and the mean length
is of 27 mm (Morrey and An 1983, O’Driscoll et al. 1992b). The anterior bundle can be further
divided into anterior and posterior bands (Morrey and An 1985; Callaway et al. 1997; Floris
et al. 1998). Some authors have included a third deep middle band (Fuss 1991; Ochi et al. 1999).
Macroscopic observation defines a visible ridge that demarcates the border between the anterior and
the posterior band (Floris et al. 1998). Histological study confirms that the insertion is not limited to
the sublime tubercle, but that some fibers course over it to insert further distally on the proximal and
medial ulna (Dugas et al. 2007). Neither the anterior nor posterior bands are isometric (Morrey and
An 1985; Fuss 1991). Between the anterior and posterior bands, the valgus stress is resisted from 30
to 120 (Safran et al. 2005). The anterior band is taut in extension and relaxes in flexion. The
posterior band is taut at intermediate positions and relaxed in extension. This is due to the ligament’s
origin being slightly posterior to the axis of rotation in flexion and extension. The middle band has
been described as being isometric throughout all the elbow range of motion. Therefore, it has been
suggested as the “guiding band” for ligament reconstruction (Fuss 1991).
Multiple techniques and modifications in bone tunnel placement have been described (Thompson
et al. 2001; Armstrong et al. 2002; Bowers et al. 2010; Slullitel and Andres 2010; Duggan
et al. 2011; Morrey 2012; McGraw et al. 2013). The main principles are currently directed to offer
Page 12 of 30
Sports Injuries
DOI 10.1007/978-3-642-36801-1_38-1
# Springer-Verlag Berlin Heidelberg 2014
Fig. 14 Medial view of the elbow bones in 90 of flexion. (a) Bone main anatomic details. (b) Drawing of the medial
collateral ligament complex and annular ligament (Adobe Photoshop). 1 Medial supracondylar ridge, 2 medial
epicondyle, 3 trochlea, 4 coronoid fossa, 5 capitulum, 6 radial head, 7 radial neck, 8 radial tuberosity, 9 olecranon, 10
coronoid process, 11 ulnar tuberosity, 12 sublime tubercle, 13 humeroradial joint, 14 proximal radioulnar joint, 15
humeroulnar joint, 16 anterior bundle of the medial collateral ligament, 17 posterior bundle of the medial collateral
ligament, 18 transverse bundle of the medial collateral ligament, 19 annular ligament. # Pau Golano
excellent exposure, avoid detachment of the flexor–pronator mass, and reconstruct the isometric
fibers of the “guiding band” (Safran et al. 2005). The anterior bundle, as the primary restraint to
valgus stress of the elbow from 30 to 120 of elbow flexion (i.e., functional range of motion), has
been the focus of multiple studies in order to assist in surgical reconstruction techniques (Munshi M
et al. 2004; Dugas et al. 2007; Miyake et al. 2012). The native ligament provides a good reference for
tunnel placement.
Despite some controversy, it has been reported that the ligament attachments or footprints
correspond to two osseous landmarks: the humeral epicondyle and the ulnar sublime tubercle
(Figs. 14 and 15). The footprint of the anterior bundle has been described in more detail, as it is
considered the main medial ligamentous stabilizer. The surface areas of the humeral and ulnar
attachments have been measured as 45.5 and 127.8 mm2, respectively (Dugas et al. 2007). The mean
width of the anterior bundle footprint on the ulna has been reported to be 5.8 mm (range 5 to 7 mm)
(Floris et al. 1998). Some authors have described a longer ulnar attachment that extends distally
along the ulna (Farrow et al. 2011) (Fig. 16). However, in cases of complete ligament tear, anatomic
Page 13 of 30
Sports Injuries
DOI 10.1007/978-3-642-36801-1_38-1
# Springer-Verlag Berlin Heidelberg 2014
Fig. 15 Medial osteoarticular view of the elbow showing the morphology of the medial collateral ligament during the
range of motion. (a) Elbow in extension, (b) elbow at 90 of flexion, (c) elbow in maximal flexion. 1 Medial epicondyle,
2 sublime tubercle, 3 anterior bundle of the medial collateral ligament, 4 transverse bundle of the medial collateral
ligament, 5 posterior bundle of the medial collateral ligament, 6 annular ligament, 7 biceps brachii tendon (cut) at the
level of its insertion in the radial tuberosity, 8 oblique cord, 9 interosseous membrane. # Pau Golano
Page 14 of 30
Sports Injuries
DOI 10.1007/978-3-642-36801-1_38-1
# Springer-Verlag Berlin Heidelberg 2014
Fig. 16 Medial osteoarticular view of the elbow showing the longer ulnar footprint of the anterior bundle according to
the description of Farrow (Farrow et al. 2011). 1 Medial epicondyle, 2 sublime tubercle, 3 anterior bundle of the medial
collateral ligament, 4 transverse bundle of the medial collateral ligament, 5 posterior bundle of the medial collateral
ligament, 6 annular ligament, 7 biceps brachii tendon (cut) at the level of its insertion in the radial tuberosity, 8 ulnar
tuberosity, 9 medial collateral footprint at the level of medial collateral ulnar ridge (Farrow et al. 2011). # Pau Golano
Fig.17 Posterior view of osteoarticular dissection of the elbow at 90 of flexion showing the posterior insertion of the
medial collateral ligament. 1 Posterior bundle of the medial collateral ligament. # Pau Golano
Page 15 of 30
Sports Injuries
DOI 10.1007/978-3-642-36801-1_38-1
# Springer-Verlag Berlin Heidelberg 2014
measurements may help to place the graft in the anatomic position. The humeral tunnel should be
placed at the flat portion of the anterior and inferior aspects of the medial epicondyle, approximately
13 mm from the most prominent point on the epicondyle. Distally, the graft should be centered on the
most prominent area of the sublime tubercle, leaving 2–3 mm of bone between the graft and the
margin of the ulnar cartilage surface (Dugas et al. 2007).
The posterior bundle (or posterior oblique ligament) is a fan-shaped ligament that is best defined
at 90 of flexion (Morrey and An 2000) (Figs.15 b, c and 17). Its average width is of 5–8 mm
(Morrey and An 1985; Timmerman and Andrews 1994). Its origin is on the posterior and distal
aspects of the medial epicondyle, and it inserts on the medial olecranon (Pollock et al. 2009).
The transverse bundle offers little contribution to elbow stability due to its origin and insertion
both on the ulna. The origin is on the tip of the olecranon and inserts on the coronoid process. This
bundle horizontally spans the insertion of the anterior and posterior bundles while covering a
depression of the medial ulna below the ulnar notch. Its fibers are intimately attached to the capsule
and are difficult to separate (Morrey and An 2000; Alcid et al. 2004) (Figs. 14 and 15).
Fig. 18 Lateral view of the elbow bones at 90 of flexion. (a) Bone main anatomic details. (b) Drawing of the lateral
collateral ligament complex (Adobe Photoshop). 1 Lateral supracondylar ridge, 2 lateral epicondyle, 3 capitulum,
4 radial fossa, 5 radial head, 6 radial neck, 7 radial tuberosity, 8 olecranon, 9 supinator crest, 10 humeroradial joint, 11
humeroulnar joint, 12 annular ligament, 13 radial collateral ligament, 14 lateral ulnar collateral ligament, 15 accessory
collateral ligament. # Pau Golano
Page 16 of 30
Sports Injuries
DOI 10.1007/978-3-642-36801-1_38-1
# Springer-Verlag Berlin Heidelberg 2014
Fig. 19 Lateral osteoarticular view of the elbow at 90 of flexion showing the morphology of the lateral collateral
ligament complex. 1 Lateral epicondyle, 2 supinator crest, 3 annular ligament, 4 radial collateral ligament, 5 biceps
brachii tendon (cut) at the level of its insertion in the radial tuberosity. # Pau Golano
Arthroscopically these bundles of the MCL can be visualized partially. Only the anterior 20–30 %
of the anterior bundle can be seen from an anterior portal, and only the posterior 30–50 % of the
posterior bundle can be visualized from a posterior portal (Timmerman and Andrews 1994). This
may limit the value of arthroscopy to assess MCL injuries.
Lateral Collateral Ligament Complex
The lateral collateral ligament complex (LCL) consists of four components, including the annular
ligament, the radial collateral ligament, the lateral ulnar collateral ligament, and the accessory
collateral ligament described by Martin (1958) (Figs. 18 and 19). The components of this ligament
complex have been found to have more variability among individuals than the MCL (Morrey and An
2000). The insertion of this complex on the ulna has been described as either blending with the
lateral ulnar collateral ligament and annular ligament or being a more distinct insertion of the two
ligaments (Cohen and Hastings 1997). The reason for this controversy might be that the LCL
complex blends with the fibers of the annular ligament, the surrounding muscles, and the fascia,
being consequently difficult to individualize. Macroscopically there is no clear separation between
the lateral ulnar collateral ligament and the radial collateral ligament proximal to the annular
ligament (O’Driscoll et al. 1992a; Olsen et al. 1996; Zoner et al. 2010). Likewise, in magnetic
resonance imaging studies, it cannot be distinctly separated (Cotten et al. 1997; Terada et al. 2004).
The LCL complex originates along the inferior surface of the lateral epicondyle, near the axis of
rotation of the elbow, being therefore taut throughout elbow range of motion because of its isometric
position (Morrey and An 1985).
The lateral ulnar collateral ligament described by O’Driscoll (O’Driscoll et al. 1992a) is a
separate, posterior portion of the radial collateral ligament, which blends with the annular ligament
and attaches to the supinator crest on the ulna. It is taut in flexion beyond 110 and becomes lax in the
Page 17 of 30
Sports Injuries
DOI 10.1007/978-3-642-36801-1_38-1
# Springer-Verlag Berlin Heidelberg 2014
Fig. 20 Anterior view of osteoarticular dissection of the proximal radioulnar joint showing the anatomical morphology
of the annular ligament. 1 Annular ligament, 2 radial collateral ligament (cut), 3 radial head, 4 radial neck, 5 biceps
brachii tendon (cut) at the level of its insertion in the radial tuberosity, 6 oblique cord. # Pau Golano
presence of valgus stress. The lateral ulnar collateral ligament is the primary restraint of varus stress,
and its insufficiency leads to posterolateral rotatory instability of the elbow (O’Driscoll et al. 1992c).
Similarly to the MCL, many techniques have been described for reconstruction of the LCL (King
et al. 2002; Lehman 2005; Gong et al. 2009; Rhyou and Park 2011; Jones et al. 2012). Regardless of
the technique, the isometric placement of the humeral attachment is critical in LCL reconstruction.
The isometric point is at the center of the capitulum, which is distal to the lateral epicondyle. The
ulnar tunnel is created near the tubercle of the supinator crest by either one or two drill holes
depending on the technique (AAOS 2008).
The annular ligament is a strong band originating and inserting to the anterior and posterior
margins of the radial notch enveloping the radial head and stabilizing the proximal radioulnar joint
(Figs. 19 and 20). The anterior insertion becomes taut during supination and the posterior origin
becomes taut in pronation (Morrey and An 2000). A dissection study (Bozkurt et al. 2005) described
inferior and superior oblique bands of the annular ligament. They both form a crosswise feature as
oblique groups of fibers crossing over the annular ligament. Superficially, fibers of the supinator
muscle are intimately fused with fibers of the annular ligament. They have been suggested to help the
capsule and the synovial fold to move in harmony with the motion of the radius. Below the radial
head, the diameter of the ring formed by the annular ligament narrows, providing a tight fit at the
neck of the radius. Proximally, it is wider at the level of the radial head, and a small tear at this level
has been reported to be the first step in nursemaid’s elbow (Kaplan and Lillis 2002). When studied
histologically, the annular ligament is continuous with the joint capsule, LCL complex, and
Page 18 of 30
Sports Injuries
DOI 10.1007/978-3-642-36801-1_38-1
# Springer-Verlag Berlin Heidelberg 2014
supinator muscle fibers. Therefore, it has been postulated that injury to one structure may be
associated with injury to the adjacent structures as well (Sanal et al. 2009).
The radial collateral ligament inserts onto the annular ligament. It has an average length of 20 mm
and width of 8 mm. It also serves as a partial origin for the supinator muscle on the surface of the
ligament (Alcid et al. 2004).
The accessory collateral ligament is formed from a band of the annular ligament and attaches on
the supinator crest along with the lateral ulnar collateral ligament. It stabilizes the annular ligament
during varus stress (Morrey and An 2000).
Additional ligaments have been described by classical anatomists, and they include the quadrate
ligament and the oblique ligament. The quadrate ligament is a thin fibrous layer of the capsule which
runs from the inferior margin of the annular ligament to the ulna and contributes to stability during
pronosupination, reinforcing the annular ligament (Spinner and Kaplan 1970). The oblique ligament
is a small fascial thickening of the deep head of the supinator between the supinator crest and the
radius just below the radial tuberosity. It is considered to have limited functional importance
(Morrey and An 2000).
In summary, the MCL complex consists of the anterior, posterior, and transverse bundles and is
involved in the pathoanatomy of throwing athletes. The anterior bundle is the major constraint of
valgus stress and its course is mimicked in reconstruction techniques. The LCL complex shows
higher anatomic variability but can generally be divided in the annular ligament, radial collateral
ligament, lateral ulnar collateral ligament, and accessory collateral ligament. The lateral ulnar
collateral ligament is the primary constraint of varus stress and acts against posterolateral rotatory
instability after traumatic or iatrogenic injuries. Due to its isometric properties, the goal of surgical
reconstruction is to reproduce the functional anatomy of the lateral ulnar collateral ligament (AAOS
2008).
Musculature
The elbow musculature can be classified in four main muscle groups: the anterior or elbow flexors,
the posterior or elbow extensors, the lateral or wrist extensor–supinators, and the medial or wrist
flexor–pronators.
The muscle groups overlying the humerus are confined by the brachial fascia. The arm has two
compartments: anterior and posterior. The medial and lateral intermuscular septae separate the
anterior compartment (biceps brachii and brachialis muscles) from the posterior compartment
(triceps brachii muscle) in the distal two thirds of the arm.
The forearm muscles are surrounded by the antebrachial fascia which is the continuation of the
brachial fascia. The forearm has three compartments: anterior or volar (for superficial and deep
flexor muscular groups), posterior or dorsal (for extensor muscles), and lateral (for extensor and
supinator muscles).
The details of origin, insertion, function, and innervation of each muscle are summarized in
Table 2.
Muscles of the Arm
The anterior group of muscles in the arm is composed of the biceps brachii and brachialis muscles.
The biceps brachii inserts as a thick tendon but has also a fascial insertion. The bicipital aponeurosis,
also known as lacertus fibrosus, follows a medial and anterior course from the biceps brachii and
merges with the forearm fascia which covers the wrist flexor–pronator muscles.
Page 19 of 30
Sports Injuries
DOI 10.1007/978-3-642-36801-1_38-1
# Springer-Verlag Berlin Heidelberg 2014
Table 2 Musculature of the elbow
Muscle
Elbow flexors
Biceps brachii
Brachialis
Origin
Insertion
Short head: tip of coracoid
process of scapula
Long head: supraglenoid
tubercle of scapula
Distal half of anterior surface of
humerus
Radial tuberosity and Forearm supination
fascia of forearm via Elbow flexion when
bicipital aponeurosis supinated
Elbow
extensors
Triceps brachii Long head: infraglenoid tubercle
of scapula
Lateral head: posterior surface of
humerus (superior to radial
groove)
Medial head: posterior surface of
humerus (inferior to radial
groove)
Wrist Flexors
Pronator Teres Medial epicondyle of humerus
and coronoid process of ulna
Flexor carpi
Medial epicondyle of humerus
radialis
Palmaris
Medial epicondyle of humerus
longus
Flexor
digitorum
superficialis
Flexor carpi
ulnaris
Flexor
digitorum
profundus
Humeroulnar head: medial
epicondyle of humerus, ulnar
collateral ligament, and coronoid
process of ulna
Radial head: superior half of
anterior border of radius
Humeral head: medial
epicondyle of humerus
Ulnar head: olecranon and
posterior border of ulna
Proximal ¾ of medial and
anterior surfaces of ulna and
interosseous membrane
Coronoid process
and tuberosity of
ulna
Function
Elbow flexion
Proximal end of
Elbow extension
olecranon and fascia Humeral head
of forearm
stabilization
Mid 1/3 of lateral
surface of radius
Base of second
metatarsal
Flexor retinaculum
and palmar
aponeurosis
Middle phalanges of
lateral digits
Elbow flexion
Forearm pronation
Wrist flexion and
abduction
Wrist flexion palmar
aponeurosis
tightening
Proximal
interphalangeal joint
flexion of lateral digits
Metacarpophalangeal
joint flexion
Wrist flexion
Pisiform bone, hook Wrist flexion and
of hamate bone, and ulnar deviation
fifth metacarpal bone
Base of distal
phalanx of lateral
digits
Innervation
Musculocutaneous
nerve
Musculocutaneous
nerve and Radial
nerve
Radial nerve
Median nerve
Median nerve
Median nerve
Median nerve
Ulnar nerve
Distal interphalangeal Medial part: ulnar
joint flexion of lateral nerve
digits
Hand flexion
Lateral part:
anterior
interosseous nerve
(branch of median
nerve)
(continued)
Page 20 of 30
Sports Injuries
DOI 10.1007/978-3-642-36801-1_38-1
# Springer-Verlag Berlin Heidelberg 2014
Table 2 (continued)
Muscle
Origin
Wrist extensors
Anconeus
Lateral epicondyle of humerus
Insertion
Function
Innervation
Lateral surface of
olecranon and
superior part of
posterior surface of
ulna
Elbow extension
(assists triceps)
Elbow joint
stabilization
Ulnar abduction
during pronation
Elbow flexion
Radial nerve
Brachioradialis Proximal 2/3 of lateral
supracondylar ridge of humerus
Extensor carpi Lateral supracondylar ridge of
radialis longus humerus
Extensor carpi Lateral epicondyle of humerus,
radialis brevis lateral collateral ligament
Extensor
Lateral epicondyle of humerus
digitorum
communis
Radial styloid
process of radius
Base of second
metacarpal
Base of third
metacarpal
Extensor expansion
of lateral digits
Extensor digiti Lateral epicondyle of humerus
minimi
Extensor expansion
of fifth digit
Extensor
indicis
Posterior surface of ulna and
interosseous membrane
Extensor carpi Humeral head: lateral epicondyle
ulnaris
of humerus
Ulnar head: posterior border of
ulna
Supinator
Superficial head: lateral
epicondyle of humerus, radial
collateral and annular ligaments,
and supinator crest of ulna
Deep head: supinator fossa and
supinator crest
Extensor expansion
of second digit
Base of fifth
metacarpal
Wrist extension and
radial deviation
Wrist extension and
radial deviation
Wrist extension
Metacarpophalangeal
joint extension of
lateral digits
Metacarpophalangeal
and interphalangeal
joints extension of
fifth digit
Metacarpophalangeal
and interphalangeal
joints extension of
second digit
Hand extension
Wrist extension and
ulnar deviation
Forearm supination
Lateral, posterior,
and anterior surfaces
of proximal 1/3 of
radius
Elbow flexion
Radial nerve
Radial nerve
Radial nerve
Posterior
interosseous nerve
(branch of radial
nerve)
Posterior
interosseous nerve
(branch of radial
nerve)
Posterior
interosseous nerve
(branch of radial
nerve)
Posterior
interosseous nerve
(branch of radial
nerve)
Posterior
interosseous nerve
(branch of radial
nerve)
The posterior compartment of the arm is occupied by the main extensor muscle of the elbow, the
triceps brachialis. This muscle is composed of three heads which converge into a single tendon
broadly inserting into the olecranon.
Muscles of the Forearm
The flexor–pronator muscles originate from the medial epicondyle. They fan out laterally to
medially as the pronator teres, flexor carpi radialis, palmaris longus, and flexor carpi ulnaris.
A method to easily remember their course can be performed by placing the contralateral hand
with the palm lying flat over the medial epicondyle and the fingers equally spread out along the
forearm (Henry 1970). The thumb would correspond to the course of the pronator teres, the index
Page 21 of 30
Sports Injuries
DOI 10.1007/978-3-642-36801-1_38-1
# Springer-Verlag Berlin Heidelberg 2014
Fig. 21 Mnemotechnic rule of Henry to identify the flexor–pronator muscles of the forearm with the fingers of
the hand. 1 Pronator teres muscle, 2 flexor carpi radialis muscle, 3 palmaris longus muscle, 4 flexor carpi ulnaris
muscle. # Pau Golano
finger to the flexor carpi radialis, the middle finger to the palmaris longus, and the ring finger to the
flexor carpi ulnaris (Fig. 21). The pronator teres originates as two heads, one at the lower part of the
medial supracondylar ridge and another at the medial epicondyle. It inserts in the middle of the
lateral surface of the radius. The flexor carpi ulnaris lies directly over the MCL complex and
contributes significantly to valgus stability. Secondarily, the flexor digitorum superficialis may
also support valgus stability in greater degrees of extension as its origin is from the MCL complex
(Timmerman and Andrews 1994; Park and Ahmad 2004). The flexor digitorum superficialis is
located in the middle layer of the forearm.
Laterally, the extensor and supinator muscles originate at the lateral epicondyle and support the
LCL complex to provide stability against varus stress. The mobile wad of three is a term coined by
Henry (Henry 1970) to include the brachioradialis, extensor carpi radialis longus, and the extensor
carpi radialis brevis. This group of muscles is thus named because they can be easily mobilized,
providing a useful guide to the deeper structures in the forearm. They are retracted laterally as a
group and constitute the border of the internervous plane when performing an anterior approach to
the forearm (Henry’s approach). These three muscles act as flexors of the elbow joint. The extensor
digitorum originates just distal to the extensor carpi radialis brevis. In lateral epicondylitis, tenderness is elicited at the origin of the extensor carpi radialis brevis, just anterior and distal to the
Page 22 of 30
Sports Injuries
DOI 10.1007/978-3-642-36801-1_38-1
# Springer-Verlag Berlin Heidelberg 2014
Fig. 22 Transversal section at the level of the proximal radioulnar joint (vascular and nervous structures have been
colored with Adobe Photoshop). 1 Radial head, 2 ulna, 3 proximal radioulnar joint, 4 annular ligament, 5 median nerve,
6 radial nerve (motor and sensitive branches), 7 musculocutaneous nerve, 8 ulnar nerve, 9 posterior antebrachial
cutaneous nerve, 10 medial antebrachial cutaneous nerve, 11 humeral artery and veins, 12 cephalic vein, 13 communicating venous branch (cut) between the superficial veins and humeral veins, 14 brachialis muscle, 15 biceps brachii
tendon, 16 anconeus, 17, extensor wrist muscle group, 18 lateral collateral ligament, 19 flexor carpi ulnaris, 20
flexor–pronator wrist muscles group. # Pau Golano
epicondyle, as it is the most commonly affected muscle, although extensor carpi radialis longus,
extensor digitorum, and extensor carpi ulnaris may be involved (Hsu et al. 2012). The anconeus is a
small muscle with a narrow origin on the more posterior aspect of the lateral epicondyle just anterior
to the extensor carpi ulnaris origin and a broad insertion at the proximal ulna. The lateral approach to
the radial head (or anconeus approach) uses the plane between the anconeus and the extensor carpi
ulnaris muscles. The anconeus muscle is thought to act as a dynamic constraint to varus and
posterolateral rotatory instability. The extensor digiti minimi muscle originates from the common
extensor tendon and along with the extensor indicis are responsible for the ability to fully extend the
index and little fingers separately. The extensor indicis muscle tendon is usually harvested to be used
as a tendon graft. To localize both the extensor indicis and the extensor digiti minimi muscles, it is
important to note their ulnar position when compared to the extensor digitorum tendon at the level of
the wrist and hand. The supinator muscle originates from two heads, the superficial and the deep.
Neurovascular
A thorough knowledge of the elbow neurovascular anatomy is essential to perform safe surgical
open approaches and for arthroscopic portals placement, as well as for diagnosing potential sites of
compression.
Four main nerves have their course around the elbow: the musculocutaneous, the radial, the
median, and the ulnar (Fig. 22).
The musculocutaneous nerve is derived from the lateral cord of the brachial plexus (Cervical 5, 6,
and 7 nerve roots). It innervates and pierces the coracobrachialis muscle 5–8 cm distal to the
Page 23 of 30
Sports Injuries
DOI 10.1007/978-3-642-36801-1_38-1
# Springer-Verlag Berlin Heidelberg 2014
coracoid process and continues distally between the brachialis and biceps which innervates as well.
It terminates as the lateral antebrachial cutaneous nerve, which emerges laterally to the distal biceps
tendon and brachioradialis (Hoppenfeld and DeBoer 2009).
The radial nerve is derived from the posterior cord of the brachial plexus (Cervical 5 to Thoracic
1). It travels down, from medial to lateral, in the radial groove of the posterior humerus. At the distal
third of the humerus, the nerve pierces the lateral intermuscular septum to run between the brachialis
and brachioradialis muscles. In the cubital fossa, anterior to the humeroradial joint, it divides into the
posterior interosseous nerve (mainly motor nerve) and the superficial radial nerve (sensory nerve).
The point of bifurcation varies among individuals and can occur within an area 3 cm proximal or
distal to the elbow joint (Fuss and Wurzl 1991). The posterior interosseous nerve passes the recurrent
radial artery and its concomitant veins (also known as the leash of Henry) and enters underneath the
proximal edge of the supinator muscle (arcade of Fröhse) to continue distally on the dorsal aspect of
the forearm. The superficial radial nerve travels beneath the brachioradialis muscle (O’Driscoll et al.
1992c). The radial and posterior interosseous nerves innervate several muscles (Table 2), and the
latter also gives sensory and proprioceptive functions for the posterior capsule of the wrist joint
(Portilla Molina et al. 1998).
The radial nerve may be compressed proximally, distally, or at the level of the elbow. A high
compression prior to its division at the level of the elbow results in loss of both motor and sensory
functions. After muscular effort spontaneous lesions at this level have been reported (Lotem
et al. 1971). Compression of the superficial radial nerve leads to a sensory loss, whereas the
compression of the posterior interosseous nerve within the radial tunnel results in two distinct
syndromes: the posterior interosseous nerve syndrome (motor loss) and the radial tunnel syndrome
(pain syndrome) (Dawson et al. 1990). The radial tunnel is a 5 cm long space bounded by brachialis
muscle and biceps brachii tendon medially and the mobile wad of three, anterolaterally, beginning
proximal to the humeroradial joint and ending at the distal edge of the supinator (Loh et al. 2004).
There are a few different anatomic structures that may account as sites of compression, all of them
within 5 cm of each other (Kotani et al. 1995). This is important when performing a decompression
because of the concept of the double crush or simultaneous double site of compression. It is
recommended that all structures to be evaluated. These are the fibrous or muscular connections
from the biceps brachii to the brachioradialis muscles that form the roof of the radial tunnel, the
radial recurrent artery (leash of Henry), the tendinous margin of the extensor carpi radialis brevis
muscle, the fibrous proximal edge of the supinator muscle (arcade of Fröhse) which is the
most common site of compression, and the distal border of the supinator muscle (Cardasco and
Parkes 1995). Radial tunnel syndrome is the compression of the nerve in these elbow structures and
can be confused with lateral epicondylitis. In the latter, the tender site is at the lateral epicondyle, at
the level of the origin of the extensor–supinator muscle group, whereas with compressive neuropathy it is tender approximately 1.5 cm anterior and distal to the epicondyle. Compression of the
nerve can be seen in swimmers and tennis players due to repeated pronation and supination (Hsu
et al. 2012). The presence of any motor symptoms is more likely to be due to injury of the posterior
interosseous nerve, which supplies the extensor muscles of the hand. The radial sensory nerve can be
compressed in the forearm near to the wrist, and it has been termed Wartenberg’s syndrome.
The median nerve is formed from the medial and lateral cords of the brachial plexus (Cervical 5 to
Thoracic 1). The nerve runs with the brachial artery in the arm, medial to the brachialis muscle. In the
cubital fossa, both structures lie medial to the biceps brachii tendon and underneath the bicipital
aponeurosis. At this level, the nerve lies medial to the artery. The median nerve continues between
Page 24 of 30
Sports Injuries
DOI 10.1007/978-3-642-36801-1_38-1
# Springer-Verlag Berlin Heidelberg 2014
the two heads of the pronator teres muscle into the forearm between the flexor digitorum superficialis
and flexor digitorum profundus muscles. It gives off the anterior interosseous nerve approximately
2–5 cm distal to the medial epicondyle and travels along the interosseous membrane. Compressive
neuropathy of the median nerve is most frequently seen at the level of the transverse carpal ligament
of the wrist. Proximal compression, known as the pronator teres syndrome, may develop as a result
of a lacertus fibrosus, pathology within the pronator tunnel, and a tendinous edge of the flexor
digitorum superficialis arch. Athletic activities that involve repetitive pronation of the forearm, such
as baseball and racket sports, may irritate the median nerve at this level (Cardasco and Parkes 1995).
The ulnar nerve is formed from the medial cord of the brachial plexus (Cervical 8 to Thoracic 1).
At the level of the elbow, the nerve enters into the cubital tunnel posterior to the medial epicondyle
and then continues to the anterior compartment of the forearm between the two heads of the
flexor carpi ulnaris muscle, lying on the flexor digitorum profundus muscle. The cubital tunnel is
a fibro-osseous ring, the roof of which is formed by a fascial sheath described by Osborne going
from the medial humeral epicondyle to the olecranon (Osborne 1957). Ulnar nerve compression in
the cubital tunnel is the second most common nerve entrapment in the upper extremity. The nerve
can be compromised by any thickening of the tunnel. In athletes, ulnar nerve irritation may occur
secondary to the throwing motion.
At the region of the elbow, there are numerous sensory nerves that lie subcutaneous and are at risk
during surgical approaches or portal placement. The medial brachial cutaneous nerve innervates the
posteromedial aspect of the arm down to the olecranon. The medial antebrachial cutaneous nerve
innervates the medial aspects of the elbow and forearm. The posterior antebrachial cutaneous nerve,
a branch of the radial nerve, gives sensation to the posterolateral elbow and the posterior forearm.
The lateral antebrachial cutaneous nerve, which is the terminal branch of the musculocutaneous
nerve, innervates the elbow and the proximal lateral forearm (Hsu et al. 2012) (Fig. 22).
The brachial artery is the continuation of the axillary artery beyond the lower margin of teres
major muscle. It travels down the arm on the anterior surface of the brachialis muscle with the
median nerve and enters the cubital fossa lateral to it and underneath the bicipital aponeurosis. In the
cubital fossa the artery is divided into the radial and ulnar arteries. The radial artery lies medial to the
biceps brachii tendon and immediately sends off the radial recurrent artery, before continuing
superficial to the supinator and the pronator teres muscles, deep to the brachioradialis muscle. The
radial artery runs close to the superficial radial nerve. The ulnar artery exits the cubital fossa
underneath the deep head of the pronator teres muscle and distally underneath the flexor carpi
ulnaris and flexor digitorum superficialis muscles, lying on the surface of the flexor digitorum
profundus muscle. The ulnar artery travels along with the ulnar nerve. Similar to the radial artery,
just after its division, the ulnar artery gives off the anterior and posterior interosseous arteries and the
ulnar recurrent artery. The latter runs with the ulnar nerve initially (Hoppenfeld and DeBoer 2009).
The superficial veins running across the cubital fossa are useful sites for venipuncture. Various
patterns have been described but generally two main veins can be easily localized: the cephalic vein
along the medial border of the fossa and the basilic vein along the lateral. The median cubital vein
connects obliquely between these two main veins. The median antebrachial vein opens into the
basilic vein or into the median cubital vein depending on the pattern. Additional superficial veins
above the cephalic and basilic veins have been described (Mikuni et al. 2013) (Fig. 23).
Page 25 of 30
Sports Injuries
DOI 10.1007/978-3-642-36801-1_38-1
# Springer-Verlag Berlin Heidelberg 2014
Fig. 23 Anterior view of the cubital fossa showing the superficial veins. (a) Surface anatomy. (b) Surface anatomy with
veins colored with Adobe Photoshop. 1 Cephalic vein, 2 basilic vein, 3 median cubital vein, 4 median antebrachial vein,
5 accessory cephalic vein. # Pau Golano
Conclusion
Surface anatomy of the elbow serves useful to reveal muscular or osseous lesions as the elbow is a
superficial joint. When performing elbow arthroscopy, bony landmarks and soft spots are important
for correct portal placement.
Thanks to its morphology the elbow is a very congruous joint. Some osseous landmarks are
important in determining the origin and insertion of muscular or ligamentous structures. Especially
relevant are the footprints of the two ligamentous complexes: MCL and LCL. They are involved in
the pathoanatomy of throwing athletes or in elbow dislocations and instability. Sound anatomic
knowledge will assist the surgeon in ligamentous reconstruction procedures.
Recognition of the four muscle groups that course around the elbow is paramount in open
approaches and in the treatment of muscular injuries. Also, four main nerves cross the elbow and
innervate each one of these four muscle groups. For schematic purposes, this relationship is as
follows: elbow flexors–musculocutaneus nerve, elbow extensors–radial nerve, wrist extensor–supinators–radial nerve, and wrist flexor–pronators–median and ulnar nerves. Several sites of entrapment of these nerves around the elbow can cause neuropathies in athletes with repetitive motion.
Page 26 of 30
Sports Injuries
DOI 10.1007/978-3-642-36801-1_38-1
# Springer-Verlag Berlin Heidelberg 2014
This chapter provides the sports physician or surgeon with the anatomical knowledge necessary
for treatment of the most frequent elbow conditions in athletes.
References
AAOS (2008) Orthopaedic knowledge update: Shoulder and elbow. AAOS 3, 3rd edn, American
Academy of Orthopaedic Surgeons. Rosemont, IL, USA. pp 451–460 and 461–476
Alcid JG, Ahmad CS, Lee TQ (2004) Elbow anatomy and structural biomechanics. Clin Sports Med
23(4):503–517
Armstrong AD, Dunning CE, Faber KJ et al (2002) Single-strand ligament reconstruction of the
medial collateral ligament restores valgus elbow stability. J Should Elb Surg 11(1):65–71
Beckett KS, McConnell P, Lagopoulos M et al (2000) Variations in the normal anatomy of the
collateral ligaments of the human elbow joint. J Anat 197(3):507–511
Bowers AL, Dines JS, Dines DM et al (2010) Elbow medial ulnar collateral ligament reconstruction:
clinical relevance and the docking technique. J Should Elb Surg 19(Suppl 2):110–117
Bozkurt M, Acar HI, Apaydin N et al (2005) The annular ligament: an anatomical study. Am J Sports
Med 33(1):114–118
Bryce CD, Armstrong AD (2008) Anatomy and biomechanics of the elbow. Orthop Clin N Am
39(2):141–154
Byram IR, Kim HM, Levine WN et al (2013) Elbow arthroscopic surgery update for sports medicine
conditions. Am J Sports Med 41(9):2191–2202
Cage DJ, Abrams RA, Callahan JJ et al (1995) Soft tissue attachments of the ulnar coronoid process:
an anatomic study with radiographic correlation. Clin Orthop 320:154–158
Callaway GH, Field LD, Deng XH et al (1997) Biomechanical evaluation of the medial collateral
ligament of the elbow. J Bone Joint Surg Am 79(8):1223–1231
Cardasco FA, Parkes JC 2nd (1995) Chapter 17: Overuse injuries of the elbow. In: Nicholas JA,
Hershman EB (eds) The upper extremity in sports medicine, 2nd edn. Mosby, Missouri,
pp 317–330
Cohen MS, Hastings H 2nd (1997) Rotatory instability of the elbow. The anatomy and role of the
lateral stabilizers. J Bone Joint Surg Am 79(2):225–233
Cotten A, Jacobson J, Brossmann J et al (1997) Collateral ligaments of the elbow: conventional MR
imaging and MR arthrography with coronal oblique plane and elbow flexion. Radiology
204(3):806–812
Dawson DM, Hallet M, Millender LH (1990) Radial nerve entrapment. In: Dawson DM, Hallet M,
Millender LH (eds) Entrapment neuropathies, 2nd edn. Little, Brown, Boston, pp 199–233
Deutch SR, Olsen BS, Jensen SL et al (2003) Ligamentous and capsular restraints to experimental
posterior elbow joint dislocation. Scand J Med Sci Sports 13(5):311–316
Dugas JR, Ostrander RV, Cain EL et al (2007) Anatomy of the anterior bundle of the ulnar collateral
ligament. J Should Elb Surg 16(5):657–660
Duggan JP Jr, Osadebe UC, Alexander JW et al (2011) The impact of ulnar collateral ligament tear
and reconstruction on contact pressures in the lateral compartment of the elbow. J Should Elb Surg
20(2):226–233
Farrow LD, Mahoney AJ, Stefancin JJ et al (2011) Quantitative analysis of the medial ulnar
collateral ligament ulnar footprint and its relationship to the ulnar sublime tubercle. Am
J Sports Med 39(9):1936–1941
Page 27 of 30
Sports Injuries
DOI 10.1007/978-3-642-36801-1_38-1
# Springer-Verlag Berlin Heidelberg 2014
Floris S, Olsen BS, Dalstra M et al (1998) The medial collateral ligament of the elbow joint: anatomy
and kinematics. J Should Elb Surg 7(4):345–351
Fuss FK (1991) The ulnar collateral ligament of the human elbow joint: anatomy, function and
biomechanics. J Anat 175(Apr):203–212
Fuss FK, Wurzl GH (1991) Radial nerve entrapment at the elbow: surgical anatomy. J Hand Surg
[Am] 16(4):742–747
Gong HS, Kim JK, Oh JH et al (2009) A new technique for lateral ulnar collateral ligament
reconstruction using the triceps tendon. Tech Hand Upper Extrem Surg 13(1):34–36
Gray H (1918) Gray’s anatomy, 20th edn. Lea & Febiger, New York, pp 321–322
Henry AK (1970) Extensile exposure. E&S Livingstone, Edinburgh, p 94
Hoppenfeld S, DeBoer P (2009) Surgical exposures in orthopaedics: the anatomic approach.
Lippincott Williams & Wilkins, Philadelphia, pp 111–147
Hsu SH, Moen TC, Levine WN et al (2012) Physical examination of the athlete’s elbow. Am J Sports
Med 40(3):699–708
Jones KJ, Dodson CC, Osbahr DC et al (2012) The docking technique for lateral ulnar collateral
ligament reconstruction: Surgical technique and clinical outcomes. J Should Elb Surg
21(3):389–395
Kaplan RE, Lillis KA (2002) Recurrent nursemaid’s elbow (annular ligament displacement):
treatment via telephone. Pediatrics 110(1):171–174
King JW, Brelsford HJ, Tullos HS (1969) Analysis of the pitching arm of the professional baseball
pitcher. Clin Orthop Relat Res 67:116–123
King G, Morrey BF, An K (1993) Stabilizers of the elbow. J Should Elb Surg 2(3):165–174
King GJ, Dunning CE, Zarzour ZD et al (2002) Single-strand reconstruction of the lateral ulnar
collateral ligament restores varus and posterolateral rotatory stability of the elbow. J Should Elb
Surg 11(1):60–64
Kotani H, Miki T, Senzoku F et al (1995) Posterior interosseous nerve paralysis with multiple
constrictions. J Hand Surg [Am] 20(1):15–17
Lehman RC (2005) Lateral elbow reconstruction using a new fixation technique. Arthroscopy
21(4):503–505
Loh YC, Lam WL, Stanley JK et al (2004) A new clinical test for radial tunnel syndrome: the rule of
nine test: a cadaveric study. J Orthop Surg (Hong Kong) 12(1):83–86
Lotem M, Fried A, Levy M et al (1971) Radial palsy following muscular effort. A nerve compression syndrome possibly related to a fibrous arch of the lateral head of the triceps. J Bone Joint Surg
(Br) 53(3):500–506
Martin BF (1958) The annular ligament of the superior radio-ulnar joint. J Anat 92(3):473–482
McGraw MA, Kremchek TE, Hooks TR et al (2013) Biomechanical evaluation of the docking plus
ulnar collateral ligament reconstruction technique compared with the docking technique. Am
J Sports Med 41(2):313–320
Mikuni Y, Chiba S, Tonosaki Y (2013) Topographical anatomy of superficial veins, cutaneous
nerves, and arteries at venipuncture sites in the cubital fossa. Anat Sci Int 88(1):46–57
Miyake J, Moritomo H, Masatomi T et al (2012) In vivo and 3-dimensional functional anatomy of
the anterior bundle of the medial collateral ligament of the elbow. J Should Elb Surg
21(8):1006–1012
Miyasaka KC (1999) Anatomy of the elbow. Orthop Clin N Am 30(1):1–13
Morrey BF (2012) Reconstruction of the posterior bundle of the medial collateral ligament: a
solution for posteromedial olecranon deficiency-a case report. J Should Elb Surg 21(11):e16–e19
Page 28 of 30
Sports Injuries
DOI 10.1007/978-3-642-36801-1_38-1
# Springer-Verlag Berlin Heidelberg 2014
Morrey BF, An KN (1983) Articular and ligamentous contributions to the stability of the elbow
joint. Am J Sports Med 11(5):315–319
Morrey BF, An KN (1985) Functional anatomy of the ligaments of the elbow. Clin Orthop
201(Dec):84–90
Morrey BF, An KN (2000) Anatomy of the elbow joint and biomechanics of the elbow. In: Morrey
B (ed) The elbow and its disorders. WB Saunders, Philadelphia, pp 13–60
Morrey BF, Askew LJ, Chao EY (1981) A biomechanical study of normal functional elbow motion.
J Bone Joint Surg Am 63(6):872–877
Munshi M, Pretterklieber ML, Chung CB et al (2004) Anterior bundle of ulnar collateral ligament:
evaluation of anatomic relationships by using MR imaging, MR arthrography, and gross anatomic
and histologic analysis. Radiology 231(3):797–803
Novak CB, Mehdian H, von Schroeder HP (2012) Laxity of the ulnar nerve during elbow flexion
and extension. J Hand Surg [Am] 37(6):1163–1167
O’Driscoll SW, Morrey BF, An KN (1990) Intraarticular pressure and capacity of the elbow.
Arthroscopy 6(2):100–103
O’Driscoll SW, Horii E, Morrey BF, Carmichael SW (1992a) Anatomy of the ulnar part of the lateral
collateral ligament of the elbow. Clin Anat 5(4):296–303. DOI: 10.1002/ca.980050406
O’Driscoll SW, Jaloszynski R, Morrey BF et al (1992b) Origin of the medial ulnar collateral
ligament. J Hand Surg [Am] 17(1):164–168
O’Driscoll SW, Morrey BF, Korinek S et al (1992c) Elbow subluxation and dislocation: a spectrum
of instability. Clin Orthop Relat Res 280:186–197
Ochi N, Ogura T, Hashizume H et al (1999) Anatomic relation between the medial collateral
ligament of the elbow and the humero-ulnar joint axis. J Should Elb Surg 8(1):6–10
Olsen BS, Vaesel MT, Søjbjerg JO et al (1996) Lateral collateral ligament of the elbow joint:
anatomy and kinematics. J Should Elb Surg 5(2):103–112
Osborne GV (1957) The surgical treatment of tardy ulnar neuritis. J Bone Joint Surg (Br) 39:782
Park MC, Ahmad CS (2004) Dynamic contributions of the flexor-pronator mass to elbow valgus
stability. J Bone Joint Surg Am 86(10):2268–2274
Pollock JW, Brownhill J, Ferreira LM et al (2009) Effect of the posterior bundle of the medial
collateral ligament on elbow stability. J Hand Surg [Am] 34(1):116–123
Portilla Molina AE, Bour C, Oberlin C et al (1998) The posterior interosseous nerve and the radial
tunnel syndrome: an anatomical study. Int Orthop 22(2):102–106
Prasad A, Robertson DD, Sharma GB et al (2003) Elbow: the trochleogingylomoid joint. Semin
Musculoskelet Radiol 7(1):19–25
Regan WD, Korinek SL, Morrey BF et al (1991) Biomechanical study of ligaments around the
elbow joint. Clin Orthop 271:170–179
Reichel LM, Morales OA (2013) Gross anatomy of the elbow capsule: a cadaveric study. J Hand
Surg [Am] 38(1):110–116
Rhyou IH, Park MJ (2011) Dual reconstruction of the radial collateral ligament and lateral ulnar
collateral ligament in posterolateral rotator instability of the elbow. Knee Surg Sports Traumatol
Arthrosc 19(6):1009–1012
Rosenberg BM, Loebenberg MI (2007) Elbow arthroscopy. Bull NYU Hosp Jt Dis 65(1):43–50
Safran M, Ahmad CS, Elattrache NS (2005) Ulnar collateral ligament of the elbow. Arthroscopy
21(11):1381–1395
Sanal HT, Chen L, Haghighi P et al (2009) Annular ligament of the elbow: MR arthrography
appearance with anatomic and histologic correlation. AJR Am J Roentgenol 193(2):122–126
Page 29 of 30
Sports Injuries
DOI 10.1007/978-3-642-36801-1_38-1
# Springer-Verlag Berlin Heidelberg 2014
Slullitel MH, Andres GE (2010) New technique of reconstruction for medial elbow instability. Tech
Hand Upper Extrem Surg 14(4):266–269
Spinner M, Kaplan EB (1970) The quadrate ligament of the elbow: Its relationship to the stability of
the proximal radio-ulnar joint. Acta Orthop Scand 41(6):632–647
Terada N, Yamada H, Toyama Y (2004) The appearance of the lateral ulnar collateral ligament on
magnetic resonance imaging. J Should Elb Surg 13(2):214–216
Thompson WH, Jobe FW, Yocum LA et al (2001) Ulnar collateral ligament reconstruction in
athletes: muscle splitting approach without transposition of the ulnar nerve. J Should Elb Surg
10(2):152–157
Timmerman LA, Andrews JR (1994) Histology and arthroscopic anatomy of the ulnar collateral
ligament of the elbow. Am J Sports Med 22(5):667–673
Van Riet RP, Van Glabbeek F, Neale PG et al (2004) Anatomical considerations of the radius. Clin
Anat 17(7):564–569
Zoner CS, Buck FM, Cardoso FN et al (2010) Detailed MRI-anatomic study of the lateral
epicondyle of the elbow and its tendinous and ligamentous attachments in cadavers. AJR Am
J Roentgenol 195(3):629–636
Page 30 of 30
View publication stats