The Minimal Clinically Important Difference, Patient Acceptable Symptom State, and Clinical Outcomes of Anterior Cruciate Ligament Repair Versus Reconstruction: A Matched-Pair Analysis From the SANTI Study Group.

BACKGROUND

There has been increasing interest in anterior cruciate ligament (ACL) repair because of theoretical advantages over ACL reconstruction; however, the contemporary literature has failed to provide high-quality evidence to demonstrate these advantages.

PURPOSE

To compare the clinical and functional outcomes of ACL repair versus ACL reconstruction at a minimum follow-up of 2 years.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Patients who underwent ACL repair were propensity matched (based on demographics, time between injury and surgery, knee laxity parameters, presence of meniscal lesions, preoperative activity level, and sport participation), in a 1:1 ratio, to those who underwent ACL reconstruction during the same period. Isokinetic testing was used to evaluate strength deficits at 6 months postoperatively. Knee laxity parameters were evaluated at 12 months. Complications, return to sport, and patient-reported outcome scores were recorded at final follow-up.

RESULTS

In total, 75 matched pairs (150 patients) were evaluated. The repair group had significantly better mean hamstring muscle strength at 6 months compared with the reconstruction group (1.7% ± 12.2% vs -10.0% ± 12.8%, respectively; < .0001). At a mean final follow-up of 30.0 ± 4.8 months, the repair group had a significantly better mean Forgotten Joint Score-12 (FJS-12) score compared with the reconstruction group (82.0 ± 15.1 vs 74.2 ± 21.7, respectively; = .017). Noninferiority criteria were met for ACL repair, compared with ACL reconstruction, with respect to the subjective International Knee Documentation Committee score (86.8 ± 9.0 vs 86.7 ± 10.1, respectively; < .0001) and side-to-side anteroposterior laxity difference (1.1 ± 1.4 vs 0.6 ± 1.0 mm, respectively; < .0001). No significant differences were found for other functional outcomes or the pivot-shift grade. There were no significant differences in the rate of return to the preinjury level of sport (repair group: 74.7%; reconstruction group: 60.0%; = .078). A significant difference was observed regarding the occurrence of ACL reruptures (repair group: 5.3%; reconstruction group: 0.0%; = .045). Patients who experienced a failure of ACL repair were significantly younger than those who did not (26.8 vs 40.7 years, respectively; = .013). There was no significant difference in rupture rates between the repair and reconstruction groups when only patients aged >21 years were considered (2.9% vs 0.0%, respectively; = .157). The minimal clinically important difference and Patient Acceptable Symptom State (PASS) thresholds were defined for the ACL repair group. A significantly greater proportion of patients in the repair group achieved the PASS for the FJS-12 compared with their counterparts in the reconstruction group (77.3% vs 60.0%, respectively; = .034).

CONCLUSION

ACL repair was associated with some advantages over ACL reconstruction including superior hamstring muscle strength at 6 months and significantly better FJS-12 scores. However, the failure rate was significantly higher after ACL repair, and younger patients were particularly at risk.