Concomitant distal femoral osteotomy in managing chronic patellofemoral instability with an associated valgus deformity: A case report and review of literature

Patellofemoral dislocation is a significant clinical condition that can evolve into chronic patellofemoral instability (PFI), leading to debilitating symptoms and functionality impairment. Although the "un menu a la carte" guideline exists for PFI cases, it lacks recommendations regarding the role of varus-producing osteotomies in addressing patellofemoral malalignment. In this case report, we present a 37-year-old woman with chronic PFI at the left knee and an associated moderate bilateral valgus deformity. Imaging studies revealed a ruptured medial patellofemoral ligament (MPFL), patellar chondral defect, patellar tilt, patella alta, trochlear dysplasia, borderline tibial tuberosity-trochlear groove (TT-TG) distance, and moderate valgus deformity. The surgical intervention included MPFL reconstruction, lateral release, cartilage microfracture, tibial tubercle (TT) medialization and distalization, and a lateral open wedge distal femoral osteotomy (DFO). At six months postoperatively, the patient could perform normal daily activities with slight pain during moderate activities. One year postoperatively, the patient reported being pain-free and was able to return to her previous activity levels. Based on our experience, in cases of PFI accompanied by valgus malalignment, a hip-knee-ankle (HKA) angle >= 5 degrees is already considered indicative of the need for varus-producing osteotomies. Failure to address the proper alignment in such cases might contribute to the risk of redislocation following surgical stabilization.