Abstract
PURPOSE: To compare 5-year patient-reported outcomes between hamstring tendon (HT) and bone-patellar tendon-bone (BPTB) autografts in primary anterior cruciate ligament reconstruction (ACLR), with particular focus on kneeling difficulties, extension deficits, and other functional limitations that have not been examined in long-term follow-up studies. METHODS: This retrospective analysis of prospectively collected data from the Norwegian Knee Ligament Register included 10,329 patients who underwent primary ACLR between 2004 and 2017 using either HT (n = 6650) or BPTB (n = 3679) autografts with 5-year follow-up. Primary outcomes were assessed using specific KOOS questions: P1 (knee pain frequency), S4 (knee extension ability), and SP5 (kneeling difficulty). Secondary outcomes included achieving Patient-Acceptable Symptom State (PASS) thresholds for KOOS Sport/Recreation ( ≥ 75.0) and Quality of Life ( ≥ 62.5) subscales. Multivariable logistic regression analyses were performed to identify factors associated with treatment success or failure, adjusting for age, sex, activity level, cartilage injury, meniscal injury, and time from injury to surgery. RESULTS: Among 10,329 patients available for evaluation from 19,564 eligible procedures (53% follow-up response rate), HT grafts demonstrated a significantly reduced risk of kneeling difficulties (SP5) at 5-year follow-up compared to BPTB grafts (OR 0.57, 95% CI 0.51-0.62, p < 0.001). HT recipients had higher odds of achieving PASS for the Sport/Recreation subscale (OR 1.29, 95% CI 1.19-1.41, p < 0.001), but showed no difference in achieving PASS for Quality of Life. Risk factors for worse outcomes included female sex, cartilage injury, delayed surgery ( > 12 months), and participation in pivoting sports at injury. CONCLUSIONS: This represents the first 5-year comparative study examining graft-specific differences in kneeling difficulties and extension deficits following ACLR. HT autografts significantly reduced the risk of kneeling problems and improved KOOS Sport/Recreation outcomes compared to BPTB grafts, while showing comparable results for pain and extension. These findings provide evidence for personalised discussions about graft selection. LEVEL OF EVIDENCE: Level III.