Background: Several modifiable pathologic variables can contribute to lateral patellar instability, including trochlear dysplasia, increased tibial tubercle to trochlear groove (TT-TG) distance, femoral valgus alignment, and the integrity of the medial patellofemoral ligament (MPFL). Indications: For patients with a failed primary MPFL reconstruction or those with extreme pathoanatomy, adjunctive surgeries may be chosen in an a la carte approach to correct the pathoanatomy contributing to patellar instability. This case describes the treatment of a patient with severe trochlear dysplasia, femoral valgus alignment, increased TT-TG, and a torn MPFL treated with a 4-;pronged approach, including a trochleoplasty, distal femoral osteotomy (DFO), tibial tubercle osteotomy (TTO), and MPFL reconstruction. Technique Description: The patient is prepped and draped in a standard fashion. A medial incision is made over the distal femur. We begin with the DFO, utilizing a custom guide to remove a 6-;mm bone wedge before reduction and plating. Attention is then turned to the TTO. A freehand, 30° cut is made with an oscillating saw distally while an osteotome completes the osteotomy proximally. The tibial tubercle wedge is left without fixation while attention is turned to the trochleoplasty. A modified recession wedge technique is used to optimize the morphology of the trochlear groove. The trochleoplasty is secured with a central knotless polyether ether ketone (PEEK) anchor with sutures to 3 other anchors surrounding the lateral trochlea. The tubercle wedge is translated 10 mm anteromedially and 6 mm distally before fixation. Finally, the MPFL reconstruction is performed with 2 knotless PEEK patella anchors and a semitendinosus allograft. Care is taken to ensure the graft supplies appropriate patellar stabilization through flexion before final fixation. Results: Patients undergoing this 4-;pronged approach for severe lateral patellar instability are expected to return to activities of daily life. Rigorous physical therapy is needed immediately after surgery until at least 6 months postoperatively, with attention to restoring range of motion to prevent arthrofibrosis of the knee. Discussion/Conclusion: Patellar stabilization with concurrent trochleoplasty, DFO, TTO, and MPFL reconstruction can be used to treat patients with multiple pathoanatomic risk factors contributing to patellar instability. This level of surgery should only be implemented after careful selection of patients.
Haneberg et al. (Mon,) studied this question.