This patient is a healthy, young female who presents with a primary complaint of bilateral anterior knee pain. These symptoms began shortly after beginning intensive training for a half-marathon, which she has been participating in for a few months now. In the beginning, the pain would not begin until the end of the run, then progressed to the middle of the run, and finally now is present throughout the entire run. She actually experiences pain during activities of daily living at this point as well. This pain is described as diffuse general knee pain that can vary between anterior and posterior knee regions with the right knee being more symptomatic than the left. The pain has not radiated distal or proximal to the knee region. There was no traumatic incident that brought on the symptoms. Additionally, she experiences pain during weight-bearing functional activities (squats, lunges, ect.) with increasing angles of knee flexion leading to increased pain. Her primary goal at the time of evaluation was to be pain-free and prepared to complete her half-marathon (~1 month away). Her primary care physician performed x-ray imaging and found minimal joint space narrowing of the medial tibiofemoral compartments bilaterally. There were no other significant findings from this radiological report.
Upon static observation, she demonstrates fairly significant genu varum, squinting patellae, and ‘toe-in’ bilaterally. Prior to beginning examination, fracture at the knee region was ruled out via the Ottawa Fracture Rules and prior radiological findings.
Movement analysis utilizing the lateral step-down and drop jump tasks showed several areas of concern. The lateral step down showed an uncompensated trendelenburg posture at the pelvis with a forward trunk lean. Additionally, the drop jump task showed decreased knee flexion with her knees extending well past her toes at impact. Both tasks elicited pain with the drop jump being most problematic.
During the physical examination, she stated tenderness to palpation of medial and lateral joint-lines bilaterally, but no significant findings with palpation to the soft tissue structures in the knee region.
Range of motion testing indicated a small deficit bilaterally in knee flexion/extension with increased pain associated with end-range knee flexion. There were no significant findings at either the hip or ankle in terms of ROM limitation. Crepitiation was noted throughout entire knee flexion/extension ROM. Accessory motion was WNL for tibiofemoral, patellofemoral, and tibiofibular motion.
Manual muscle testing results seem to indicate a bilateral limitation in hip abduction, external rotation, and extension strength with no deficits found in the musculature at the knee. She did experience pain with knee flexion and extension, but this pain did not implicate the hamstring or quadriceps musculature as the pain was once again a diffuse general knee pain and could not be localized to these specific muscle groups or their associated connective tissue.
Based on the prior examination findings, meniscal pathology seemed to be a likely hypothesis as 2 variables identified by Lowery et al to be indicative of a meniscus tear were present (pain with passive knee flexion and joint-line tenderness). With these 2 findings alone, they found that there was a specificity of 71.6%, sensitivity of 51.4%, and a positive predictive value of 65.5%. Unfortunately, no other factors were present in this patient to help increase the likelihood of this diagnosis (McMurray Test, pain with Modified Bounce-Home Test, and history of catching/locking were all negative). Patellofemoral special testing indicated a lateral pull of the patella and pain following the patellar compression test. Both of these implicate potential mal-tracking and subsequent altered patellofemoral contact area and articular cartilage damage. This suspected altered contact area did correlate well with the findings of the movement analysis and manual muscle testing.
So, if this was your patient, what would you hypothesize the underlying pathology to be? What else would you test? How would you move forward with treatment?