Previous authors have suggested that the analgesic effects of intra-articular morphine may be beneficial. Clonidine has been found to potentiate the analgesic effect of morphine. Following knee arthroscopy, morphine has demonstrated equivocal effect in comparison to bupivicaine for analgesia while circumventing the issue of chondrotoxicity. There have been no studies evaluating the effect of intra-articular morphine following hip arthroscopy. The purpose of this study was to evaluate the efficacy of intra-articular morphine in combination with clonidine on pain and narcotic consumption following hip arthroscopy surgery for femoroacetabular impingement.

A retrospective review was performed on 43 patients that underwent hip arthroscopy between September 2014 and May 2015 at our institution for femoroacetabular impingement. All patients received preoperative Celebrex and Tylenol per our anesthesia protocol, and 22 patients received an additional intra-articular injection of 10 mg morphine and 100 mcg of clonidine at the conclusion of the procedure. Narcotic consumption, duration of anesthesia recovery, and perioperative pain scores were compared between the two groups.

We found that patients who received intra-articular morphine and clonidine used significantly less opioid analgesic in the PACU, with 23 mEq of morphine equivalents required in the intra-articular morphine and clonidine group compared to 40 mEq of opiod equivalents in the non-injection group (p=0.0259). There were no statistically significant differences in time spent in recovery prior to discharge or in VAS pain scores recorded immediately post-operatively and at one hour following surgery.

In conclusion, we found that an intraoperative intra-articular injection of morphine and clonidine significantly reduced the amount of narcotic requirement following hip arthroscopy. We do believe that there may be significant benefits to this, including less systemic effects from overall narcotic usage in the perioperative period. Our study demonstrated a beneficial effect of intra-articular morphine that may help with overall pain improvement, less narcotic consumption, and improved patient satisfaction following outpatient hip arthroscopy. This study provides the foundation for future research currently being conducted in a randomised-control setting.