Patellar Tendon Repair Restores Extensor Mechanism Function with a Low Complication Rate: A Systematic Review

Introduction The patellar tendon plays a crucial role in knee extension and lower extremity mobility. Although PT ruptures are rare, they result in severe loss of function when untreated. The purpose of this study was to evaluate clinical and functional outcomes and complications following primary, acute patellar tendon (PT) repair. Methods In accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, PubMed, Embase, and Cochrane Library databases were searched in August 2024 for studies published after 2004. Studies were included if they met these criteria: evaluated patients who underwent acute PT repair with any technique including for mid-substance tear or avulsion, were prospective or retrospective studies, and reported functional outcomes or complications. Studies not written in English were excluded. Results The initial screen identified 1737 studies, 9 of which were included in this systematic review. There were three retrospective cohort studies, three retrospective case series, one retrospective case control study, and two prospective case series. Each study had low risk of bias. A total of 970 patients (93.8 % males) were included. Mean age across studies ranged from 32.1 to 44.6 years. Five included studies reported on mean extension at follow-up, ranging from 0 to 6.4 degrees of extension. Five included studies reported on mean flexion at follow-up, ranging from 128.5 to 143.3 degrees of flexion. The range of re-rupture and re-operation were 0–21.4 % with an overall re-rupture rate of 3.9 % and an overall re-operation rate of 5.7 %. Only one study reported a significant difference in re-rupture rates with transosseous repair versus suture anchor repair (7.5 % versus 0 % respectively). Other complications identified were venous thromboembolism (VTE) (0–5.0 %), stiffness (0–35.0 %), hardware discomfort (0–5.0 %), and infection (0–5.0 %). Conclusions Patellar tendon repair with both transosseous and suture anchor technique restores range of motion in patients post-operatively with a low complication rate. Decisions regarding operative technique should be tailored to individual patient characteristics and surgeon preferences. Level of evidence Level IV, systematic review of level III-IV studies.