Treating Patellar Instability After Total Knee Arthroplasty with Medial Retinaculum Reconstruction: A Clinical Case and Narrative Review

Abstract

Background: Patellar instability after a total knee arthroplasty is a disabling complication that often needs surgical revision, prolonging hospital in-stay and rehabilitation. Different surgical techniques exist in literature and no one seem superior to the other in terms of outcome. Clinical Case: 67 years-old patient who underwent kinematic-aligned TKA experienced patellar dislocation during the rehabilitation program. After three months of conservative treatment, patellar instability was still present and thus revision surgery was suggested. Patellar resurfacing, lateral patellar retinacular release and MPFL reconstruction with a cadaveric gracilis tendon was performed. Discussion: Once malalignment of the prosthesis is excluded, soft-tissues imbalance should be considered as the main risk factor for patellar instability. A chance should be given to conservative treatment, but usually a revision surgery is required. The decision to use a cadaveric graft was made to shorten the rehabilitation, also considering the functional requirements of our patient. Conclusion: After the revision surgery, no new episodes of patellar dislocation occurred to our patient. The choice of the graft and the surgical technique seem safe and minimally invasive, guaranteeing a faster and shorten recovery, which is especially important in older patients.