Background: Primary anterior cruciate ligament (ACL) repair (ACLPR) demonstrates promising short-term clinical outcomes in select patients; however, it remains poorly understood as to whether previously reported short-term outcomes are maintained at midterm follow-up. Purpose: To determine whether short-term (2-year) outcomes are maintained at 5 years after ACLPR, evaluate age-stratified failure and reoperation rates, and identify preoperative risk factors for failure. Study Design: Case series; Level of evidence, 4. Methods: This prospective study included the first 113 consecutive patients with proximal (type I/II) ACL tears who underwent ACLPR between 2008 and 2017 with a minimum 5-year follow-up. Failure rates were recorded based on instrumented laxity (>3-mm anterior tibial translation side-to-side difference), pivot-shift grade (grade ≥2), and subjective instability. Patient Acceptable Symptom State thresholds were established based on collected patient-reported outcome measure scores. Logistic regression models were constructed to determine associations with independent risk factors for failure. Results: A total of 107 patients (median age, 35.5 years [interquartile range, 22.4-43.1 years]) were available at final follow-up (median, 6.0 years [interquartile range, 5.3-7.0 years]). No significant differences were reported in failure rates between 2- and 5-year follow-up: overall non–age-differentiated: 11.5% versus 15.9%, respectively ( P = .34); ≤21 years: 37.0% versus 38.5%, respectively ( P = .92); and >21 years: 3.5% versus 8.6%, respectively ( P = .16). No failures occurred in patients aged ≤21 years, while 4 failures occurred in patients aged >21 years. Additionally, no significant differences were observed in overall non–age-differentiated reoperation rates (6.2% vs 7.5%, respectively; P = .71) and contralateral ACL injury rates (3.5% vs 4.7%, respectively; P = .67). Clinical outcomes and patient-reported outcome measure scores did not significantly differ between time points, and most patients met Patient Acceptable Symptom State thresholds (88% for International Knee Documentation Committee form, 91% for Lysholm scale, 93% for Forgotten Joint Score–12, and 84% for ACL–Return to Sport after Injury scale; all P < .001). Preoperative risk factor analysis only revealed younger age as negatively impacting ipsilateral ACL failure, as the odds decreased by 12.5% for each year of increasing age ( P = .002). Conclusion: Sustained clinical and functional outcomes for ACLPR were observed between short-term and midterm follow-up, with failure rates of 11.5% and 15.9%, respectively. Although younger age was an important risk factor for ipsilateral ACL failure, with a high failure rate of 37.0% in patients aged ≤21 years at short-term follow-up, no additional failures were observed at midterm follow-up. In contrast, patients aged >21 years experienced modest failure rates, increasing from 3.5% at short-term follow-up to 8.6% at midterm follow-up, with no significant change.

中文翻译：

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初次前交叉韧带修复后的持续临床和功能结果：至少 5 年的随访研究

背景： 原发性前交叉韧带 （ACL） 修复术 （ACLPR） 在特定患者中显示出有希望的短期临床结果;然而，对于在中期随访中是否维持先前报道的短期结局，仍然知之甚少。目的： 确定 ACLPR 后 5 年是否维持短期 （2 年） 结局，评估年龄分层失败率和再手术率，并确定术前失败的危险因素。研究设计：病例系列;证据水平，4.方法： 这项前瞻性研究包括 2008 年至 2017 年间接受 ACLPR 的前 113 例连续近端 （I/II 型） ACL 撕裂患者，至少随访 5 年。根据仪器松弛度 （>3-mm 胫骨前平移侧到侧差异） 、枢轴移位等级 （≥2 级） 和主观不稳定性记录失败率。患者可接受的症状状态阈值是根据收集的患者报告结果测量分数建立的。构建 Logistic 回归模型以确定与失败的独立风险因素的关联。结果： 最终随访时共有 107 例患者 （中位年龄 35.5 岁 [四分位距，22.4-43.1 岁]） （中位年龄 6.0 岁 [四分位距，5.3-7.0 岁]）。2 年和 5 年随访之间的失败率没有显着差异： 总体无年龄差异：分别为 11.5% 和 15.9% （P = .34）;≤21 岁：分别为 37.0% 和 38.5% （P = .92）;和 >21 岁：分别为 3.5% 和 8.6% （P = .16）。≤21 岁患者未发生失败，而 >21 岁患者发生 4 次失败。 此外，在总体非年龄差异再手术率方面未观察到显著差异 （分别为 6.2% 和 7.5%;P = .71） 和对侧 ACL 损伤率 （分别为 3.5% 和 4.7%;P = .67）。临床结果和患者报告的结果测量评分在时间点之间没有显著差异，大多数患者达到患者可接受的症状状态阈值（国际膝关节文献委员会表格为 88%，Lysholm 量表为 91%，遗忘关节评分为 93%，ACL – 受伤后重返运动量表为 84%;均 P < .001）。术前危险因素分析仅显示年龄较小对同侧 ACL 衰竭产生负面影响，因为年龄每增加一年，比值降低 12.5% （P = .002）。结论： 在短期和中期随访之间观察到 ACLPR 的持续临床和功能结局，失败率分别为 11.5% 和 15.9%。尽管年轻是同侧 ACL 失败的重要危险因素，短期随访中 ≤21 岁患者的失败率高达 37.0%，但在中期随访中未观察到额外的失败。相比之下，年龄为 >21 岁的患者失败率适中，从短期随访的 3.5% 增加到中期随访的 8.6%，没有显着变化。