Primary Care Approach to
Knee Pain
Bradley Sandella, DO, ATC
Director of Sports Medicine
Sports Medicine Fellowship Program Director
Goals of Lecture
Be able to identify the most common causes
of knee pain.
 Demonstrate several examination
techniques to identify different causes of
knee pain.
 Design a Home Exercise Program for knee
pain

Epidemiology of Knee Pain

Accounts for approximately 1/3 of
musculoskeletal complaints seen in the
primary care setting.
 5-10%

With 25% being anterior knee pain


of all visits
Females more commonly get it than males
As many as 54 % of athletes have some
degree of knee pain each year
 25%
of all runners will experience
Doc....my knee hurts
Most Common Causes of Knee Pain
in Primary Care

Osteoarthritis (34%)
Meniscal injury (9%)
Collateral ligament injury (7%)
Cruciate ligament injury (4%)
Gout (2%)
Fracture (1.2%)

Undifferentiated causes including sprains and strains (42%)





Jackson J, O’Malley P, Kroenke K, “Evaluation of Acute Knee Pain in Primary Care”, Ann Intern Med 2003; 139(7):575-588.
Anatomy


Anterior
 Patella
 Posterior facets
 Alignment
 Patella Tendon
 Tibial Tubercle
 Bursas
Posterior
 Gastrocnemius
 Popliteal vessels


Medial
 Medial collateral
ligament
 Medial meniscus
Lateral
 Lateral collateral
ligament
 Lateral meniscus
Anatomy

Internal structures

Ligaments





Anterior cruciate ligament
Posterior cruciate ligament
Medial collateral ligament
Lateral collateral ligament
Cartilage


Menisci
Articular
History





Mechanism
 Acute vs. chronic pain
Unilateral vs. bilateral
Swelling / effusion
Worse with activity vs. prolonged sitting
 Stairs
Mechanical symptoms
 Giving way
 Locking / catching
It hurts right here……in the front
Anterior knee pain

Children / adolescent




Patellofemoral pain
syndrome
Patella subluxation
Patella tendinitis
Tibial apophysitis

Adult





Osteoarthritis
Pes anserine bursitis
Gout
Inflammatory
arthropathy
Septic joint
Patellofemoral Syndrome
Also referred to as Anterior knee pain or
Idiopathic anterior knee pain or
chondromalacia patella
 Retropatellar or peripatellar pain
 Results from stresses upon patellofemoral
joint

Epidemiology
Leading cause of knee pain < 45 y/o
 Females > males
 25-40% of all knee pain in sports clinics

Anatomy


Patella is sesamoid within quadriceps tendon
Articulates with trochlear groove of femur
Predisposing anatomy
Increased Q angle
 Miserable malalignment
 VL>VMO muscle imbalance
 Decreased flexibility

History
Chronic anterior knee pain
 Often bilateral
 Usually no history of acute injury
 Often unable to point to one spot
 Worse with activity
 Often worse with stairs
 Often worse with prolonged sitting

Exam

Observe active knee
extension:

Lateral tracking




Patella mobility



Patellar tilt
Tight retinaculum
Q angle
Flexibility testing
Strength testing

Single leg squat
Special testing



Patella apprehension
Patellar compression
Clark’s Inhibition test
Patellar Apprehension
 Knee
flexed to 30 deg and relaxed across thigh
 Force patella laterally with thumbs
 OBSERVE FACE – notice apprehension or
discomfort before actual dislocation
Patellofemoral Compression
Clarke’s test

Knee in full extension and relaxed
 Contract quad, ask about pain, relax quad
 Perpendicular pressure around superior patella
 with web space between thumb-index
 Re-contract quad
 Positive test = pain
Single Leg Squat
Should I order imaging?

X-ray



Ottawa Knee Rules
MRI
MRI arthrogram
But as in life….you have options
Ottawa Knee Rules






Pittsburgh Decision Rules
Age 55 or over;
Isolated tenderness of the patella;
Tenderness at the head of the fibula;
Inability to flex to 90 degrees;
Inability to walk four weight-bearing steps
both immediately and in the emergency
department.

Efficacy :
Sensitivity: 97%
Specificity: 27%
Reduced the use of knee radiographs by
28%



Blunt trauma or a fall as mechanism of
injury plus either of the following:
Age younger than 12 years or older than
50 years
Inability to walk four weight-bearing steps
in the emergency department
Efficacy:
Sensitivity: 99%
Specificity: 60%
Reduced the use of knee radiographs by
52%
Tandeter HB, Shivartzman P. Acute knee injuries: use of decision rules for selective radiograph ordering. Am Fam Physician. 1999:
X-ray




Check for:
lateral subluxation
Patella tilt
Degenerative changes
How about an MRI?

American Academy of Orthopaedic Surgeons 2011 Annual
Meeting: Abstract 299. Presented February 17, 2011.



33 patients (31%) underwent MRIs
 18 scans (55%) were classified as unnecessary because it was possible
to make the diagnosis with history, physical examination, and X-rays
alone.
Of the remaining 75 patients (69%) who presented without an MRI study
 only 4 required additional MRI evaluation, for a tentative diagnosis of
a meniscal tear in 3 patients and osteonecrosis in 1 patient
The most common final diagnosis for this cohort was osteoarthritis in 41
patients (38%), followed by patellofemoral syndrome in 14 patients (13%)
and meniscal tears in 8 patients (7%).
Treatment




Physical Therapy
Modalities
Alternative
Surgery
Physical Therapy

Strengthen VMO
 Closed
chain exercises
Hip abductor/external rotator strengthening
 IT band/ hamstring flexibility

Other modalities

Taping



Widely employed, multiple trials have shown not
significant benefit*
McConnell taping
Bracing


No good data to demonstrate benefit
Patella stabilizing brace


Palumbo knee brace
Corticosteroid injection
* Aminaka N, Gribble, PA. A Systematic Review of the Effects of Therapeutic Taping…. J. of Athl Train: 2005
Alternative treatments

Acupuncture
 In
randomized study, placebo group showed
equal benefit
 Benefit at four weeks

Chiropractic patellar mobilization
 No

statistical improvement
Manipulation
 Decreased
quadriceps inhibition
Referral to Specialist
Conservative Trial Fails- 4-6 weeks
 Effusion associated w/ AKP


Important to Answer before referral
 Is
Pain Reflex Inhibition gone?
 Is there evidence of VMO hypertrophy? If no,
compliance issues must be addressed.
Surgical intervention

Lateral release
 17-92%
pt satisfaction
Tibial tubercle advancement
 Vastus Medialis transposition
 Microfracture procedures for
chondromalacia

It is not so much pain…..but more of
an unsteady felling
Knee instability



Ligament sprain
Meniscal tear
Reflexive pain arc



Osteoarthritis
Loose body
Osteochondral defect

Osteochondritis desiccants
Statistics



100,000 ACL injuries a year
Female athletes at 2-8 times increased risk for
ACL injury than male athletes in comparable
sports
Women experience ACL tears up to nine times more often
then men.
American Family Physician; 2010

Non contact and contact mechanisms are different

70% of ACL injuries are the result of non-contact
situations
Anatomy and Function

Anatomy



2 bundles
Runs from the anterior
intercondyle region of the
tibia to the medial aspect
of the lateral condyle of
the femur
Function


Maintain rotary stability
Prevent anterior tibial
translation on the femur
Anatomy and Function

Anatomy


Crescent-shaped pads of
fibrocartilage located between
the femoral condyles and the
tibial plateaus
Function



Aid in dissipating loading forces
placed on the knee
stabilizing the knee during
rotation
lubricating the knee joint
Mechanism of Injury

Three non-contact ACL injury mechanisms
 Cutting
 Deceleration
 Landing

Non-contact injury will often occur with
jumping or landing from a jump
Theories

Neuromuscular





Anatomy



Femoral notch width
Q angle
Hormonal


Hamstring strength
Proprioception
Muscular activation
Biomechanical dynamics
Estrogen receptors on the ACL
Extrinsic factors
One plausible cause

Dynamic Neuromuscular Imbalance
 Women

run, land, and jump differently
Female athletes land with greater maximal valgus
angle*

Significant differences between dominant and nondominant knees*
Female athletes rely less on hamstring and more on
quadriceps and gastrocnemius++
 Upon landing, women tend to land with less knee
flexion*

* Mandelbaum BR et al. Effectiveness of a Neuromuscular and Proprioceptive Training …Amer Journal of Sports Medicine. 2005
++ Harmon KG, Ireland ML. Gender differences in noncontact anterior cruciate ligament injuries. Clinics in Sports Medicine. 2000
History
Acute injury
 Unilateral
 Immediate Pain – often
 Diffuse swelling – occurring 1-2 hours after
activity
 Popping – audible or felt
 Instability – knee giving way
 Catching / locking

Special Tests for Ligaments

ACL

Lachman


87% sensitive / 93 % specific
Anterior Drawer



48% sensitive / 87% specific
MCL


Valgus Stress @ 0&30
LCL

Varus Stress @ 0&30
PCL


Posterior Drawer
Sag/ Gravity Test
Jackson J, O’Malley P, Kroenke K. Evaluation of Acute Knee Pain in Primary Care. Ann Intern Med: 2003; 139(7):575-588.
Special Tests for Menisci

McMurray

52% sensitive / 97% specific
Apley Grind
 Flick


Several studies have concluded that a negative physical
exam can reliable exclude meniscal pathology
Jackson J, O’Malley P, Kroenke K. Evaluation of Acute Knee Pain in Primary Care. Ann Intern Med: 2003; 139(7):575-588
Ellis M, Meadows S, “For knee pain, how predictive is physical examination for meniscal injury?”, J Fam Pract 2004; 53(11)
Radiology

X-ray
 Often


normal
Effusion
Segond Fracture
Radiology

MRI
 Torn
ligament
Wavy appearance
 Complete void

 Loss
of PCL arc
 Bone bruising

Lateral femoral condyle
and tibial plateau
Radiology

MRI

Linear density change

Intra-substance, horizontal, or vertical



High degree injury if tear involves
travels to joint surface
Extruded tissue
sensitivity and specificity


91.4% and 81.1% - medial meniscal tear
76% and 93.3% -lateral meniscal tear
Crawford R, Walley G, Bridgman S, Maffulli N. Magnetic resonance imaging versus arthroscopy in the diagnosis of knee pathology,
concentrating on meniscal lesions and ACL tears: a systematic review. Br Med Bull. 2007
Treatment for an ACL Injury

Surgery
 Athletes
and active women
 Mechanical symptoms
 Graft selection
Autograph – patella tendon vs. hamstring
 Allograph


Non-invasive
 Physical
 Bracing
therapy
Physical Therapy

Strength training
 Quadriceps

Flexibility
 Quadriceps

– hamstring ratio
and hamstring
Proprioception
Bracing?

No evidence that pain,
range of motion, graft stability,
or protection from subsequent
injury were affected by brace use.
Bracing after ACL Reconstruction: A Systematic Review. Clinical
Orthopaedics and Related Research. 2007
Prevention

Proper training – proprioception and
neuromuscular training exercises
 Decelerate
in a more controlled fashion by
taking smaller steps than one sudden step
 Round off turns when pivoting, keeping legs
inside body shape
 Concentrate on core strength
Prevention

Prevention programs
 Prevent

Aim of program


Diminish the effect of fatigue on neuromuscular control
88% reduction in ACL injuries*
 FIFA

Injury, Enhance Performance
11+
Complete warm-up to prevent ACL injuries
* Mandelbaum BR et al. Effectiveness of a Neuromuscular and Proprioceptive Training Program in
Preventing Anterior Cruciate Ligament Injuries in Female Athletes: 2-year follow-up. American
Journal of Sports Medicine. 2005; 33(7): 1003-1010
Long-term Sequelae

Osteoarthritis in up to 90% of patients after
a previous ACL
Treatment for a Meniscal Injury
Non-surgical consideration






Symptoms develop over 24 to 48
hours after the acute injury
Able to bear weight
Minimal swelling
Knee has full range of movement
with pain only at or near full
flexion
Pain on McMurray testing occurs
only with deep knee flexion
MRI demonstrates small intrasubstance and vertical tears
Surgical consideration






After a severe twisting injury,
activity could not be resumed
Locked or restricted motion
Pain after minimal flexion in
McMurray testing
An associated ACL tear
Little improvement after 3 weeks
of non-invasive treatment
MRI demonstrates a large
complex meniscal tear
Cooper, R, Crossley, K, Morris, H.. Acute knee injuries. In: Clinical Sports Medicine, 2nd edition, Brukner, P, Khan, K (Eds), 2000
Physical Therapy

Strength training
 Quadriceps

Flexibility
 Quadriceps

– hamstring ratio
and hamstring
Proprioception
Surgery

Surgical options
 Partial

Partial meniscectomy is preferred method considering
speed of recovery and functional outcome
 Repair

or total meniscectomy
of the meniscal tear
Approach
 Arthroscopic
 Open
Chronic Degenerated Meniscal Injury

Medial meniscectomy in patients over the
age of fifty: a six year follow-up study
 20%
of good results after a degenerative
meniscal tear
Ménétrey J, Siegrist O, Fritschy D. Medial meniscectomy in patients over the age of fifty: a six year follow-up study. Swiss Surg. 2002;.
Chronic Degenerated Meniscal Injury

A Randomized Trial of Arthroscopic
Surgery for Osteoarthritis of the knee
 Arthroscopic
surgery for osteoarthritis of the
knee provides no additional benefits to
optimized physical and medical therapy
Kirkley A, et al. A Randomized Trial of Arthroscopic Surgery for Osteoarthritis of the Knee. The New England Journal of medicine. 2008.
In Conclusion
Patellofemoral is a very common problem.
An accurate diagnosis and aggressive
treatment plan can be helpful to patients.
 ACL injuries can be devastating but we may
have some ways to help prevent the injury
from occurring
 Not all meniscal injuries need surgery

References








American Academy of Orthopaedic Surgeons 2011 Annual Meeting: Abstract 299. Presented
February 17, 2011.
Aminaka N, Gribble, PA. A Systematic Review of the Effects of Therapeutic Taping on
Patellofemoral Pain Syndrome. Journal of Athletic Training: 2005
Calmbach W, Hutchens M. Evaluation of Patients Presenting with Knee Pain: Part I. History,
Physical Examination, Radiographs, and Laboratory Tests. Am Fam Physician: 2003; 68(5).
Calmbach W, Hutchens M, “Evaluation of Patients Presenting with Knee Pain: Part II. Differential
Diagnosis”, Am Fam Physician 2003; 68(5).
Crawford R, Walley G, Bridgman S, Maffulli N. Magnetic resonance imaging versus arthroscopy in
the diagnosis of knee pathology, concentrating on meniscal lesions and ACL tears: a systematic
review. Br Med Bull. 2007;84:5.
Cooper, R, Crossley, K, Morris, H.. Acute knee injuries. In: Clinical Sports Medicine, 2nd edition,
Brukner, P, Khan, K (Eds), McGraw-Hill, 2000. p.426
Ellis M, Meadows S. For knee pain, how predictive is physical examination for meniscal injury?” J
Fam Pract 2004; 53(11).
Harmon KG, Ireland ML. Gender differences in noncontact anterior cruciate ligament injuries.
Clinics in Sports Medicine, vol. 19, no. 2, pp. 287–302, 2000.
References






Jackson J, O’Malley P, Kroenke K. Evaluation of Acute Knee Pain in Primary Care. Ann Intern
Med: 2003; 139(7):575-588.
Kirkley A, et al. A Randomized Trial of Arthroscopic Surgery for Osteoarthritis of the Knee. The
New England Journal of medicine. 2008; 359(11):10971107.
Mandelbaum BR et al. Effectiveness of a Neuromuscular and Proprioceptive Training Program in
Preventing Anterior Cruciate Ligament Injuries in Female Athletes: 2-year follow-up. American
Journal of Sports Medicine. 2005; 33(7): 1003-1010.
Ménétrey J, Siegrist O, Fritschy D. Medial meniscectomy in patients over the age of fifty: a six year
follow-up study. Swiss Surg. 2002;8(3):113.
Tandeter HB, Shivartzman P. Acute knee injuries: use of decision rules for selective radiograph
ordering. Am Fam Physician. 1999: Dec;60(9):2599-608.
Wright R, Fetzer G. Bracing after ACL Reconstruction: A Systematic Review. Clinical
Orthopeadics and Related Research. 2007
Increased Q angle

Measurement



Normal angle


ASIS to mid patella
Mid patella to tibial tubercle
10-20 degrees
Lateral pull leads to abnormal
tracking
Mechanism of Injury

Anatomic Abnormality




Repetitive Microtrauma



Malalignment
Muscle imbalance
Compensation
Overuse
Growth spurts in children
Macrotrauma


Contusion
Sprain / strain