CARPAL FRACTURES AND DISLOCATIONS
FRACTURES OF THE CARPALS
 60-70 % of all carpal #s are of the scaphoid.
 The scaphoid is more susceptible to injury because it crosses two carpal rows.
SCAPHOID FRACTURES
 Fall on to the outstretched, fully dorsiflexed, radially deviated hand.
 High incidence of non union as it is often missed and the bone has poor vascularity proximally.
Blood Supply

Blood supply via ligamentous attachments
o 2 main sources (both entering scaphoid distally near tubercle)
1. volar – superficial palmar branch radial artery
2. dorsal - dorsal carpal branch radial artery
Classification
i) According to anatomic location (blood supply is from distal to proximal)

Middle third (70% of #s)  80% union

Distal third (20% of #s)  100% union

Proximal third (10% of #s)  60% union
ii) According to orientation of fracture line (Russe)
 Transverse - stable
 Horizontal oblique - stable
 Vertical oblique – unstable, high longitudinal shear
iii) According to stability and displacement
 Displacement (> 1 mm offset; > 15o of luno-capitate angulation; > 60o of scapho-lunate angulation)
indicates instability.
Stable  85% union; Unstable  65% union
 Stability necessary for (a) union and (b) normal wrist mechanics.
Diagnosis


Tendeness over anatomic snuff box

Along with routine radiological views, do scaphoid views with the wrist in radial and ulnar deviation. AP
shows #; lateral shows scapho-lunate angle. Closed fist AP views helpful.

Special investigations: Tomography, Bone scans (negative scan excludes fracture), CT, MRI.

Check for DISI and VISI or other evidence of associated peri-lunate dislocation.

Check for # capitate, triquetral and of radial or ulnar styloid #.

Check the median n, radial a etc.
Treatment
 Accurate Dx of even the slightest displacement is vital because healing depends on precise reduction. Greater
displacement results in a higher non union rate.
a) Suspected Fractures

If initial xrays do not show fracture, immobilise in short arm thumb spica and repeat x ray at 2 weeks

If xrays do not show fracture and patient is still symptomatic then bone scan
b) Undisplaced Fractures
 If promptly diagnosed and properly treated, union rate should be > 95%.
 Immobilise with wrist neutral and radially deviated, thumb abducted, IP joint free.
 Use albow elbow casts in high risk fractures
 Usually for 8-12 wks.
 Bony union seen when obliteration of fracture line on all X rays and trabeculation across the fracture line.
b) Angulated Fractures
 Scaphoid POP, AE x 16 wks.
c) Displaced Fractures
 Uncommon. Non union rates approach 50%.
 Usually require ORIF because of the increased likelihood of developing post-fracture arthritis.
 Volar or dorsal approach. Can use K wires or Herbert compression screw.
 Primary bone grafting if, due to the nature of the fracture, prolonged healing is suspected.
Indications for ORIF (Variable and controversial)
 Some advocate ORIF for even undisplaced #s to allow early motion and shorter time in POP.
 Others advocate ORIF for the following indications:
1) Displaced scaphoid #s
2) DISI rotatory subluxation
3) Foreshortening of the scaphoid
4) Cortical ring shadow sign +ve
5) Wide scapho-lunate gap
 Fixation is either with a Herbert screw via a volar approach or with K wires via a volar and dorsal approach.
Fractures of the middle and proximal third of the scaphoid:
 Middle third fractures are the most common and are notorius for their high rate of delayed union and
nonunion.
 The proximal third is poorly vascularised and is susceptible to avascular necrosis and non union.
 Avascular necrosis, although it may delay union, does not invariably lead to non union.
 Treat acute injuries as described above.
Delayed union / Non-union
 Persistence of Sx and incomplete bony union on X ray.
 If, after 8 wks of adequate treatment, signs of union are lacking, consider delayed union. Others (McC) state
that if healing does not occur within 6 months, consider non-union. SRPS state 4 months.
 Some advise trial period out of POP before diagnosing non-union, others advise radiological demonstration of
instability before making the diagnosis.
 Instability = pseudoarthrosis.
Clinically
 Many are Sx free (only radiological signs of non union).
 Some are symptomatic: Pain and discomfort on active movement.
 Clinically:  mobility of wrist, fullness in snuff box.
X Ray Changes
1. Widening of # site due to bone resorption
2. Lacunae (after 6 mths)
3. True organised pseudoarthrosis (dense # ends, translucent gap)
4. Necrosis of proximal fragment with  bone density
5. Secondary OA
Management

If asymptomatic and undisplaced with no functional deficit  Passive non intervention.

Advise patient of the possibility of late degeneration (some studies show higher risk)

Options:
1. Prolonged immbolisation has led to union in a high percentage of patients
2. Pulsed electromagnetic field therapy (PEMF)

If shows displacement or carpal collapse, recommend surgery

Early non union or minimal Sx can initially be treated with cast immobilisation.

If symptomatic (painful), requires surgery, regardless of the degenerative, avascular or cystic changes.

Choice of surgery depends on age, size of proximal segment and presence of degenerative carpal changes.

Bone grafting is the basic treatment for all non-unions.

Cooley:
85% heal following bone graft.
Avascular necrosis improved in all cases where union occurred.
Bone grafting displaced fractures tended to fail. Undisplaced fractures healed.
Pulsed Electromagnetic Field Therapy

Types
1. Invasive – surgical implantation of anode/cathode
2. Semi-invasive – percutaneous drilling of cathode, anode attached to skin
3. Non-invasive – Use of coils centered around the fracture

Not as effective as bone graft

Advantages – pain free, noninvasive and can be used in the presence of infection
Osteosynthesis

K wires best for comminuted fractures in need of internal support

Herbert screw – distal pitch is greater than proximal pitch (wider threads distally)
o Scaphoid approached distally through a volar Russe-type incision

Staples
Bone graft
 Carpal arthritis is the only absolute C/I to bone grafting.
Incisions
1. Volar (Russe)
a. hockey stick incision on radial aspect of FCR
b. important to preserve strong volar risk ligaments
c. good exposure of distal pole
2. Dorsal
a. Longitudinal incision over 3rd compartment
b. Good exposure of proximal pole
Bone graft donor
1. Iliac crest
2. Radius
Bone graft design
1. 2 corticocancellous grafts into the scaphoid excavation with cancellous sides facing each other
2. volar wedge graft to correct flexion deformity (Fisk-Fernandez)
3. Maltese cross
Matti Russe bone grafting operation:

Indicted for symptomatic, established nonunion without osteoarthritis but with satisfactory carpal alignment

Volar approach to scaphoid alongside FCR. Channel cut into bone over pseudo-arthrosis and cancellous
bone graft is laid into this channel. AE POP x 3 mths. 95% success.

Poor results if proximal segment is avascular or with carpal collapse.
Alternative bone graft procedures:
1. Murray cortical peg graft (tibila bone pegs introduced into holes drilled across #)
2. Pedicled graft
3. Herbert screw plus bone graft
Vascularised bone grafting
1. Pronator pedicl vascularised bone graft
o Block of radius (15x10x5mm) harvested along with distal pronator insertion
2. Vascular bundle implantation into proximal pole
o Corticocancellous graft plus implantation of second dorsal vascular bundle
Anatomy of the dorsal wrist arteries

posterior divisions of the anterior interosseous artery and the radial artery form the primary sources of
orthograde blood flow to the dorsal distal radius.

Four vessels, branches of these arteries, are important in the design of pedicled grafts.

Two of these are superficial to the extensor retinaculum (supraretinacular), supplying nutrient branches to the
bone underlying bony tubercles between extensor tendon compartments (intercompartmental).
o 1,2 and 2,3 intercompartmental supraretinacular

2 deep vessels on the floor of the fourth and fifth compartments
o
Fourth and fifth extensor compartment arteries (branch of AIA).

most useful pedicled VBG for a scaphoid nonunion is that based on the 1,2 ICSRA.

A volar vascularised approach has also been described using the anterior branch of the AIA pedicled back to
the palmar carpal arch,
Revision of failed bone grafting

10-30% of bone grafts will fail to unite

Options:
o If capitolunate degenerative changes – salvage procedure
o If degenerative changes at radial styloid – osteosynthesis + radial styloidectomy
o If large cysts – Maltese cross
o If proximal pole avascular then vascularised graft
o If humpback deformity, wedge graft
Salvage Procedures
 Unstable # non-unions usually will progress to further instability, collapse and OA.
 Once OA develops, salvage procedures not aimed at producing bony union are used 1. Scaphoidectomy

Total causes wrist imbalance, therefore not done

Partial is an option if the proximal fragment is small (dorsal approach)
2. Proximal row carpectomy

Contraindicated if has radiocarpal arthrosis
o Preserves better arc of motion than limited arthrodesis
3. Bentzon’sprocedure

Interpose soft tissue into the fracture

Convert painful nonunion to pain-free pseudarthrosis
4. Radial styloidectomy

Subperiosteal thru snuff box

Preserve volar radial ligaments
5. Implant arthroplasties, prostheses
6. Denervation of the wrist
7. Arthrodesis (partial or complete wrist fusion)

SLAC – scaphoid excision and fusion of capitate-hamate-lunate-triquetrum