Chondromalacia patellae (CMP)

• Chondromalacia
• Chondropathy
• Anterior knee pain
• Patellofemoral dysfunction
• Patellofemoral stress syndrome
• Patellofemoral lateral tracking
• Patellofemoral pain syndrome (PFPS)
• Patellofemoral arthralgia
• Patellofemoral compression syndrome
• Lateral patellar compression syndrome
• Excessive lateral pressure syndrome
• Patellar misalignment syndrome
• Patellalgia

• 733.92 Chondromalacia
• 717.7 Chondromalacia of patella

• M22.40 Chondromalacia patellae, unspecified knee
• M94.20 Chondromalacia, unspecified site

• Pattern 4E: Impaired Joint Mobility, Motor Function, Muscle Performance, and Range of Motion Associated With Localized Inflammation

Description

• Chondromalacia: softening of cartilage on articular surface of patella at the patellofemoral joint
• Retropatellar knee pain with patellar cartilage damage2
• Insidious onset typically defined by pain in the retropatellar or peripatellar region3
• Also known as patellofemoral pain syndrome (PFPS), “anterior knee pain syndrome”2
  • PFPS applies to patients with retropatellar pain and no cartilage damage; chondromalacia applies to patients with patellar damage2
• Structures most likely to generate patellofemoral pain: anterior synovium, infrapatellar fat pad, subchondral bone, medial or lateral retinaculum4,5

Essentials of Diagnosis

• Insidious onset aggravated by repetitive impact6
• Decreased hip stability due to muscular weakness, especially gluteus medius, may affect patellofemoral joint7,8
• Q-Angle greater than 20 degrees generally considered a structural abnormality, can put patient at risk for excessive lateral-patellar forces7
• Intermittent pain and swelling6
• Greater pronated foot posture in relaxed stance3

General Considerations

• Patellofemoral joint dysfunction includes
  • Decreased quadriceps flexibility
  • Hypermobile patella
  • Altered vastus medialis oblique (VMO) response
  • Diminished quadriceps explosive strength7

Demographics

• Chondral lesions more common, more severe in patients aged 30 years and older, and those who sustained ACL injury > 5 years prior6
• Frequently occurs among physically active populations, aged 18 to 40 years9
• Higher incidence in women than in men9

Signs and Symptoms

• Quadriceps weakness
• Patella maltracking
• Anterior knee pain with deep squatting, descending stairs, prolonged sitting7

Functional Implications

• Decreased sitting tolerance
• Difficulty descending stairs
• Decreased ability to squat

Possible Contributing Causes

• Presence of excessively pronated foot posture is then hypothesized intrinsic risk factor3
  • Restrictions of first metatarsophalangeal joint (MTPJ) and ankle dorsiflexion reported to increase and prolong rearfoot eversion, respectively3
  • Greater foot mobility and greater pronated foot posture during static stance3
• PFPS results from increased or altered patellofemoral joint loading secondary to poor patellar tracking3
• Anterior knee pain within 3 months of beginning tennis lessons7
• Tight lateral knee structures: Iliotibial band, lateral knee capsule
• Weak knee extensors: Quadriceps

Differential Diagnosis

• Patellofemoral arthritis, subluxation, instability6
• Plica Syndrome6
• Anterior knee pain6
  • Patellar subluxation, dislocation
  • Tibial apophysitis (Osgood-Schlatter’s lesion)
  • Jumper's knee (patellar tendonitis)
  • Posterior cruciate ligament (PCL) injury...