Genu Valgum and Arthritic Changes of the Tibiofemoral Joint in a 97 Year‐Old Female. Results of an Independent Dissection and Literature Review in a 3rd Year Anatomy Elective within a Doctor of Physical Therapy Curriculum

Abstract

Introduction/ObjectiveGenu valgus alignment has been found to influence the distribution of load across the articular surfaces of the tibiofemoral (TF) joint. The malalignment alters load distribution, gait mechanics and, depending on severity, can impair functional status. The symptoms and degeneration of knee osteoarthritis (OA) are related to the disruption of the articular surfaces and are associated with significant impairment in functional ability.PurposeThis project was conducted as part of an effort to vertically integrate anatomy into the clinical curriculum of the Thomas Jefferson University Doctor of Physical Therapy Program. The objective of this study was to describe the cadaver dissection findings and to research the effect of the biomechanics of a valgus knee on lateral TF OA. Implications for physical therapy treatment were also considered.Case ReportThe subject was a 97 year‐old female with unknown cause of death, who presented with severe genu valgum in her right knee. Her contralateral knee had normal alignment and, importantly, contained a prosthesis from a total knee arthroplasty. Prior to the dissection, Q angle measurements were taken and the subject was found to have a Q angle of 24 degrees. After the skin of the thigh and leg was reflected, the quadriceps tendon was cut and the patella was reflected inferiorly to open up the joint, while preserving the lateral and medial collateral ligaments. Once in flexion, both the femoral and tibial condyles showed signs of arthritic breakdown, particularly in the lateral compartment. The lateral meniscus was absent.DiscussionThe mechanics associated with a valgus knee are increased tibial abduction and external rotation, and increased hip adduction and hip internal rotation. Statically and dynamically, these mechanics increase the articular surface pressure in the lateral compartment of the knee, which is not designed to receive the brunt of the force during gait. This mechanism predisposes the lateral meniscus to injury, which is a risk factor for OA development. Once OA has developed, the valgus knee has greater risk of lateral OA progression. Our subject had a Q angle of 24 degrees which is significantly greater than the angle of 10–15 degrees considered to be normal. Not surprisingly, the arthritic changes seen in her lateral compartment during dissection were consistent with research showing a greater incidence of lateral compartment OA in persons with genu valgum.Clinical Implications for Physical TherapistsGait training and bracing is often utilized, and has been found to be beneficial for individuals who have valgus knee alignment and OA. Gait training includes increasing activation of the gluteus medius, soleus, and hip flexors. Lateral compartment knee unloader braces have been shown to decrease pain and improve functional status associated with OA.ConclusionsThe results of our dissection support prior research regarding progression of OA and genu valgum. Non‐surgical interventions on such patients performed by physical therapists may help alleviate the symptoms of lateral compartment OA.