Osteochondritis Dissecans – Knee

Lower Limb

Overview

Osteochondritis dissecans (OCD) is a condition where a segment of articular cartilage and underlying bone becomes separated from the femoral condyle, typically affecting the medial femoral condyle of the knee. This condition occurs most commonly in adolescents and young adults and can progress from stable lesions to loose bodies within the joint. Early diagnosis and appropriate management are critical to prevent premature osteoarthritis and preserve knee function.

Pathophysiology

OCD develops through repetitive microtrauma and impaired blood supply to the subchondral bone, leading to localized necrosis of bone beneath the articular cartilage. The medial femoral condyle is most vulnerable due to its tenuous blood supply and the compression forces it experiences during weight-bearing and knee flexion activities. Progressive separation occurs when mechanical forces exceed the healing capacity, potentially resulting in a loose osteochondral fragment within the joint. Factors contributing to development include genetic predisposition, anatomical variants, growth disturbances, and repetitive high-impact activities.

Patient Education

Early detection and activity modification are crucial to prevent progression; maintaining appropriate strength and flexibility through guided exercise can help stabilize the knee and reduce symptoms while healing occurs.

Typical Presentation

Site

Medial femoral condyle (70% of cases), lateral femoral condyle, or patellofemoral joint; symptoms localized to anteromedial or anterolateral knee

Quality

Poorly localized, dull ache or sharp pain with mechanical symptoms; catching or locking sensations if fragment is loose

Intensity

Variable (2-7/10) depending on stability of lesion; may be minimal at rest but increases with activity

Aggravating

Weight-bearing activities, running, jumping, squatting, pivoting movements, prolonged standing, downhill walking, knee flexion under load

Relieving

Rest, ice application, activity limitation, knee extension, non-weight-bearing positions

Associated

Effusion, quadriceps atrophy, reduced knee range of motion, hamstring tightness, mechanical symptoms (catching/locking) if loose body present, Wilson's sign (pain with knee flexion and internal tibial rotation), functional instability

Orthopaedic Tests

Wilson Test

Procedure

Patient seated with knee flexed to 90°. Examiner internally rotates the tibia while extending the knee from 90° to full extension. Patient reports pain location and timing during the movement.

Positive Finding

Sharp pain in the anteromedial knee that resolves or diminishes with external rotation of the tibia during extension

Sensitivity / Specificity

57% / 98%

Wilson, 1967; validated in multiple reviews including Verhagen et al., 2008, Cochrane

Interpretation

High specificity suggests OCD when positive; useful for ruling in OCD of the medial femoral condyle. Low sensitivity means negative test does not exclude OCD.

Lachman Test

Procedure

Patient supine with knee flexed to 20–30°. Examiner stabilises distal femur with one hand and applies anterior translation force to proximal tibia with the other hand, assessing for increased laxity or end-feel.

Positive Finding

Increased anterior tibial translation (>5–10 mm compared to contralateral knee) or soft/mushy end-feel

Sensitivity / Specificity

72% / 96%

Hegedus et al., 2015, BJSM (ACL review); applicable to OCD with concomitant ligament injury

Interpretation

May indicate associated ACL insufficiency, which can occur with OCD lesions and affect healing potential and stability. Positive result suggests need for additional ACL assessment.

Joint Line Tenderness Test

Procedure

Patient supine with knee flexed to 90°. Examiner palpates along the medial and lateral joint lines, noting specific areas of point tenderness.

Positive Finding

Focal, reproducible tenderness over the medial or lateral joint line, particularly at the site of the OCD lesion

Sensitivity / Specificity

67% / 73%

Plisky et al., 2006; classical clinical examination sign supported in orthopaedic literature

Interpretation

Moderate sensitivity and specificity; helps localise intra-articular pathology and guides imaging. Useful screening test but not diagnostic in isolation.

Thessaly Test (at 20° and 5° flexion)

Procedure

Patient stands on one leg with knee flexed to 5° (or 20°), hands on examiner's shoulders. Patient internally and externally rotates the tibia repeatedly. Examiner assesses for knee locking, catching, or pain.

Positive Finding

Joint line pain, mechanical catching sensation, or functional instability during tibia rotation

Sensitivity / Specificity

68–89% (at 5° flexion) / 89–96%

Karachalios et al., 2005, Arthroscopy; Hegedus et al., 2012, BJSM

Interpretation

High specificity for intra-articular pathology including loose bodies, cartilage lesions, and OCD fragments. Positive result supports need for imaging or arthroscopy.

Effusion Bulge Sign (Ballottement Test)

Procedure

Patient supine with knee extended and quadriceps relaxed. Examiner compresses suprapatellar pouch with one hand while tapping or stroking medial parapatellar region with the other, observing for fluid wave or distension.

Positive Finding

Visible bulge, wave, or fluid shift in the knee joint, particularly medially

Sensitivity / Specificity

69% / 68%

Medieros & Smitson, 2001; supported in standard orthopaedic examination literature

Interpretation

Indicates joint effusion (synovial inflammation/reactive fluid), common in acute OCD or following loose body creation. Suggests active intra-articular inflammation.

McMurray Test

Procedure

Patient supine, examiner flexes knee and hip. One hand grasps heel, the other palpates joint line. Examiner externally rotates tibia and extends knee (medial meniscus); then internally rotates and extends (lateral meniscus). Examiner feels for clunk or observes patient pain response.

Positive Finding

Audible or palpable 'clunk,' sharp pain at joint line, or locking during extension with rotation

Sensitivity / Specificity

48–70% / 73–98%

Hegedus et al., 2012, BJSM; systematic review of meniscal testing

Interpretation

Primarily assesses meniscal tears; in OCD context, may indicate loose body or secondary meniscal involvement. Positive result warrants imaging for associated intra-articular pathology.

⚠ Red Flags

  • •Acute traumatic onset with immediate severe pain and hemarthrosis
  • •Progressive neurological symptoms including lower limb weakness or sensory changes
  • •Signs of infection: fever, severe warmth, redness, or systemic symptoms
  • •Acute locking with inability to extend knee (loose body causing mechanical block)
  • •Signs of compartment syndrome: severe swelling, pain out of proportion, pain with passive stretch
  • •Vascular compromise: absent distal pulses, severe cold limb, color changes

⚡ Yellow Flags

  • •Young athlete with excessive training load and perfectionist traits
  • •Significant fear-avoidance behavior limiting appropriate activity progression
  • •Low mood or depression secondary to activity restriction and functional loss
  • •Pressure from parents or coaches to return to sport prematurely
  • •Psychosocial stressors coinciding with symptom onset or exacerbation
  • •Overtraining syndrome or sports-related identity issues

Osteopathic Techniques

Region

Knee joint (medial femoral condyle)

Technique

Soft Tissue

Rationale

Soft tissue mobilization to vastus medialis obliquus, medial hamstrings, and adductors reduces muscular guarding and improves local circulation to support healing without stressing the lesion site

Region

Knee joint

Technique

Articulation

Rationale

Gentle oscillatory movements within pain-free range promote synovial fluid circulation and proprioceptive feedback while maintaining joint mobility without generating excessive compressive forces across the lesion

Region

Hip and lumbar spine

Technique

MET

Rationale

Hip and lumbar mobility dysfunction alters knee biomechanics; MET to hip flexors, external rotators, and lumbar segments restores optimal alignment and reduces aberrant loading through the affected knee

Region

Ankle and foot

Technique

Articulation

Rationale

Ankle stiffness and foot dysfunction create proximal compensation patterns; restoration of ankle dorsiflexion and foot mobility normalizes lower kinetic chain alignment and reduces knee stress

Region

Quadriceps and knee extensors

Technique

Soft Tissue

Rationale

Quadriceps dysfunction contributes to patellofemoral dysfunction; targeted soft tissue work to vastus lateralis and rectus femoris improves muscular balance and dynamic knee stabilization

Region

Fascia lata and iliotibial band

Technique

Soft Tissue

Rationale

Tension in the fascia lata and ITB increases lateral knee compression; soft tissue release reduces pathological intra-articular forces and improves medial-lateral balance

Add-On Approaches

Chinese Medicine

Acupuncture at Hegu (LI4), Liangqiu (ST34), and Ashi points to promote blood circulation, reduce inflammation, and support healing of bone and cartilage; moxibustion may enhance warming and qi circulation; herbal formulae such as Du Huo Ji Sheng Tang may support bone healing and reduce pain

Chiropractic

Knee manipulation to maintain joint mobility; foot and ankle adjustments to correct biomechanical dysfunction; hip adjustment to optimize kinetic chain alignment and reduce aberrant knee loading patterns

Physiotherapy

Progressive strengthening protocol emphasizing VMO activation, hip abductor and external rotator strengthening, proprioceptive training, and gradual return-to-sport progression; neuromuscular re-education for optimal movement patterns

Remedial Massage

Deep tissue massage to quadriceps, hamstrings, and hip musculature to reduce muscular tension and improve circulation; trigger point release of vastus medialis and medial hamstrings; fascial techniques to address compensatory patterns

Rehabilitation Exercises

Supine Knee Flexion and Extension

Range of MotionBeginner

Supine Hamstring Stretch with Strap

StretchingBeginner

Quadriceps Stretch Prone or Standing

StretchingBeginner

Supine Quadriceps Sets with Isometric Hold

StrengtheningBeginner

Side-Lying Hip Abduction

StrengtheningBeginner

Prone Hip Extension

StrengtheningBeginner

Seated Knee Extension with Isometric Hold

StrengtheningIntermediate

Supine Bridge with Hip Activation

StrengtheningIntermediate

Single-Leg Stance on Stable Surface

BalanceIntermediate

Quadruped Rocking for Hip Mobility

PosturalIntermediate

Single-Leg Stance on Unstable Surface (Foam Pad or Balance Disc)

BalanceAdvanced

Single-Leg Mini Squat with Upper Limb Support

StrengtheningAdvanced

Referral Criteria

  • •Loose osteochondral fragment visible on imaging causing mechanical symptoms unresponsive to conservative care
  • •Progressive lesion enlargement or development of further separation on sequential imaging
  • •Failure to improve after 3-6 months of appropriate conservative management
  • •Recurrent effusion or swelling despite rest and activity modification
  • •Acute traumatic event with hemarthrosis or severe mechanical symptoms requiring urgent assessment
  • •Age consideration: skeletally immature patients with large lesions may require surgical evaluation to prevent progression
  • •Functional limitations affecting activities of daily living despite conservative treatment
  • •Concern regarding undiagnosed loose body or advanced cartilage degradation requiring MRI clarification