Comparing post-operative pain between single bundle and double bundle anterior cruciate ligament reconstruction: a retrospective study

BACKGROUND: In anterior cruciate ligament (ACL) reconstruction, the clinical outcome and level of post-operative pain are important factors. To date there have been no studies evaluating differences in post-operative pain between single bundle and double bundle ACL reconstruction with a hamstring graft. HYPOTHESIS/PURPOSE: We hypothesized that post-operative pain in single bundle ACL reconstruction would be less than in double bundle ACL reconstruction. This study was to compare post-operative pain between patients undergoing single bundle versus double bundle ACL reconstruction. STUDY DESIGN: Cohort study. METHODS: This was a retrospective study comparing post-operative pain scores between single bundle and double bundle ACL reconstruction. Each patient was given our standard regimen of oral diclofenac (25 mg/tab) three times per day and paracetamol (500 mg/tab) six times per day for 1 day post-operatively. If the patient complained of moderate to severe pain (pain numeric rating scale (PNRS) > 3), 3 mg of morphine was injected intravenously every 3 h for 24 h and 1 mg of morphine as a rescue medication every 1 h for 24 h. PNRS and morphine consumption were recorded at 4-h intervals for 24 h. RESULTS: 209 patients were included in this study of whom 102 and 107 patients received single bundle and double bundle ACL reconstruction, respectively. The average post-operative pain scores of the single bundle group were lower at all time points. Linear mixed effect regression analyses showed that the single bungle group had lower post-operative pain than the double bundle group after adjusting for confounders (beta = − 0.45; 95% CI = − 0.838, − 0.062) but there was no statistically significant difference between numbers of bundle ACL reconstruction with regard to morphine consumption. CONCLUSION: Single bundle ACL reconstruction had significantly lower post-operative pain scores than double bundle ACL reconstruction. CLINICAL RELEVANCE: Double bundle ACL reconstruction results in higher post-operative pain, which may slow the start of rehabilitation and reduce patient satisfaction. In middle-aged adult patients with low-demand activities, we suggest performing a single bundle ACL reconstruction.