Abstract
PURPOSE: To compare clinical outcomes between graft types and techniques used to repair chronic patellar tendon injuries to help surgeons make evidence-based decisions. METHODS: Medline, Embase, and Cochrane libraries were searched through January 2021, according to Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. Inclusion criteria were surgical treatment of chronic patellar tendon injury (defined as >6 weeks old), article available in English, and human subjects, minimum 1-year follow-up, and level of evidence I-IV. Studies describing chronic patellar tendon ruptures in the setting of total knee arthroplasty were excluded. Study quality was assessed using the Joanna Briggs Institute Critical Appraisal tools for case reports and case series. RESULTS: A total of 642 studies were identified through the initial search with 9 studies meeting all inclusion criteria. All studies included were case series encompassing 96 patients with follow-up ranging from 21 months to 7.2 years. Reconstruction techniques included the use of semitendinosus and/or gracilis tendon(s), Achilles tendon, bone-patellar tendon-bone (BTB), or direct repair. The most common graft choice was semitendinosus and/or gracilis tendon(s). Each reconstruction method yielded improvement in respect to range of motion (ROM), extensor lag, quadriceps strength, and patient-reported outcome measures (PROMs). Commonly reported complications were pain and numbness with only one reported instance of graft failure. CONCLUSIONS: In this study, we found that all reconstructive methods described in the literature can produce satisfactory outcomes with improved function, strength, and minimal complications after chronic patellar tendon ruptures. Because of study heterogeneity and low levels of evidence, consensus cannot be reached on a single superior reconstruction method. LEVEL OF EVIDENCE: Level IV, systematic review of level IV studies.