Summary

After single-bundle ACL reconstruction using a hamstring autograft, periarticular multi-drug cocktail injection reduced early postoperative pain to a greater extent than nerve block injections. Adductor canal block was added to periarticular multi-drug cocktail injection with the expectation of pain relief immediately after surgery, however, no effect was observed.

Abstract

Background

Anterior cruciate ligament (ACL) rupture is a common injury in sports medicine, for which reconstruction is the gold-standard treatment option. Notably, ACL reconstruction is usually associated with moderate-to-severe postoperative pain. Postoperative pain control after ACL reconstruction has received considerable attention, as it is the key to improving patient satisfaction and outcomes and reducing healthcare costs.
Objectives: Several pain control strategies, such as the administration of intra-articular injection, periarticular injection, and peripheral nerve blocks, especially the femoral nerve and adductor canal blocks, have been investigated. However, no reports have compared the effects of the adductor canal block combined with a lateral femoral cutaneous nerve block, periarticular injection, and periarticular injection combined with adductor canal block for pain control after ACL surgery. Therefore, this study aimed to investigate the effects of these injections on pain in the early postoperative period after ACL reconstruction.
Study Design & Methods: The study included 110 patients who had undergone primary ACL reconstruction between March 2020 and June 2024. All patients were classified as ASA physical status 1. Patients received an adductor canal block with a lateral femoral cutaneous nerve block (ACB group, n=40), periarticular multi-drug cocktail injection (PMDI group, n=40), or periarticular multi-drug cocktail injection with an adductor canal block (PMDI+ACB group, n=30). High-frequency linear-array ultrasound transducer was used for the nerve blocks. For adductor canal blocks, 10 ml of 0.75% ropivacaine was injected. 5 ml of 0.75% ropivacaine was injected for lateral femoral cutaneous nerve block. For the PMDI group, the operative orthopedic surgeon administered local infiltration analgesia with 20 ml of 7.5 mg.mL-1, ropivacaine, 20 ml of saline, and 6.6 mg of 6.6 mg.2 ml-1 dexamethasone (total, 42 ml). In the PMDI+ACB group, ropivacaine was reduced by half to 10 ml for local infiltration analgesia. Patient demographics and surgical data were analyzed. Following ACL reconstruction, patients’ numerical rating scale pain scores (0–10) were recorded at 30 min and 4, 8, 12, 24, 48, and 72 h after surgery.

Results

There were no significant differences in patient demographics and surgical data. The pain scores were significantly higher in the PMDI and PMDI+ACB group than in the ACB group 30 min after surgery. On the contrary, at 12, 24, 48, and 72 h after surgery, the pain scores were significantly lower in the PMDI and PMDI+ACB groups than in the ACB group.

Conclusions

After single-bundle ACL reconstruction using a hamstring autograft, periarticular injection reduced early postoperative pain to a greater extent than nerve block injections. ACB was added to PMDI with the expectation of pain relief immediately after surgery, however, no effect was observed.