Evaluation of Knee Extensor Mechanism Disorders: Clinical Presentation of 112 Patients

Results of physical therapy evaluation of 112 patients with extensor mechanism disorders (chondromalacia patella, infrapatellar tendinitis, and peripatellar pain) are presented. An equal number of male and female patients were evaluated and of the 73 patients with unilateral involvement (65%) there were equal numbers of right and left involved knees. Running was the activity most commonly associated with pain, followed by basketball and tennis. Stairclimbing was painful in 79% of the patients, with ascending being more painful than descending in patients reporting a clear-cut difference. Hamstring and quadriceps tightness was statistically significant relative to the uninvolved limb although clinically, negligible differences were measured. The interior pole of the patella was the most tender site to palpation, followed by medial peripatellar structures, then lateral sites. Biomechanical malalignment was not detected by the attending therapist in the majority of patients. The authors emphasize careful assessment of flexibility, quadriceps (VMO/VL) imbalance, and biomechanical alignment in performing a thorough evaluation of patients with extensor mechanism disorders.