Preemptive Analgesia in Hip Arthrosocpy: A Randomized Controlled Trial of Peri-Acetabular or Intra-Articular Bupivacaine

Introduction: Hip arthroscopy is a well-established therapeutic intervention with good outcomes for an increasing number of indications. The use of hip arthroscopy has increased in recent years as new indications and techniques are learned. However, this procedure, like other orthopedic surgeries causes moderate to severe pain and therefore requires effective pain management protocols. In addition to facilitating patient comfort, postoperative pain management allows day case surgery and has implications for the overall wellbeing and rehabilitation of the patient.

Multiple pain management protocols are used for hip arthroscopy but little published data exists on preemptive analgesia for hip arthroscopy. This study aimed to evaluate and compare the efficacy of intra articular and peri-acetabular blocks in postoperative pain control after hip arthroscopy.

Materials and Methods: Forty three consecutive patients scheduled for hip arthroscopy were randomized into 2 postoperative pain control groups. One group received preemptive intra articular 20 ml of Bupivacaine 0.5% injection and the second group received preemptive peri-acetabular 20 ml of Bupivacaine 0.5% injection. Data were compared with respect to postoperative pain with visual analog scale (VAS) and analgesic consumption, documented in a pain diary for two weeks after surgery.

Results: 21 patients were treated with intra-articular injection and 21 patients with peri-acetabular injection. There were no significant differences with regards to patient demographics, or surgical procedures. Some VAS scores recorded during the first 18 hours after surgery were significantly lower in the peri-acetabular group compared to the intra-articular group (p<0.05), this trend was not significant in the next 14 postoperative days. There were no differences between the groups with regard to analgesic consumption.

Conclusion: Peri-acetabular injection of Bupivacaine 0.5% is superior to intra-articular injection in pain reduction after hip arthroscopy for the first 18 hours. However, total analgesic consumption over the first two postoperative weeks as well as VAS pain measurements are not significantly affected.