A 30-year-old runner develops anterior knee pain aggravated by prolonged sitting, stair climbing, and squatting. Examination reveals lateral patellar tilt on passive patellar mobility testing and positive Clarke's sign. The primary pathological mechanism is:
- A Medial retinaculum laxity allowing patella to sublux medially
- B Cruciate ligament laxity causing patellofemoral incongruence
- C Lateral retinaculum tightness and vastus medialis obliquus (VMO) weakness causing lateral patellar maltracking with excessive patellofemoral contact pressure ✓
- D Tibial torsion causing mechanical overload of the lateral patellar facet
Explanation
Patellofemoral pain syndrome (PFPS) is caused by lateral maltracking of the patella due to relative tightness of the lateral retinaculum (iliotibial band) combined with weakness of the VMO, which normally provides medial stabilizing force on the patella. This imbalance increases lateral patellar tilt and contact stress on the lateral facet cartilage. Clarke's sign (pain on resisted quadriceps contraction with proximal patellar pressure) supports the diagnosis. Conservative management includes VMO strengthening, patellar taping (McConnell), hip abductor strengthening, and lateral retinaculum stretching. Lateral release is reserved for documented lateral tilt unresponsive to rehabilitation.
Reference: Maheshwari Essential Orthopaedics, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.