The AAHKS Clinical Research Award: Liposomal Bupivacaine and Periarticular Injection Are Not Superior to Single-Shot Intra-articular Injection for Pain Control in Total Knee Arthroplasty.

BACKGROUND: Intraoperative injections can help reduce early postoperative pain in total knee arthroplasty. We proposed that liposomal bupivacaine would not be superior to more common and cheaper injections. METHODS: A single-blinded prospective randomized study with 207 consecutive patients was completed. Patients were randomized to treatment with periarticular liposomal bupivacaine injection, periarticular injection of bupivacaine/morphine, or intra-articular injection of bupivacaine/morphine at the conclusion of the procedure. Postoperative visual analog pain scores and narcotic consumption were recorded and analyzed. RESULTS: There was no significant difference in postoperative visual analog pain scores or narcotic consumption among the 3 study groups. CONCLUSION: Intra-articular injection of bupivacaine and morphine is as effective for postoperative pain control in total knee arthroplasty as periarticular bupivacaine/morphine injection and liposomal bupivacaine. Use of liposomal bupivacaine in total knee arthroplasty is costly and not justified.

Pelvic tilt is minimally changed by total hip arthroplasty.

BACKGROUND: While surgical navigation offers the opportunity to accurately place an acetabular component, questions remain as to the best goal for acetabular component positioning in individual patients. Overall functional orientation of the pelvis after surgery is one of the most important variables for the surgeon to consider when determining the proper goal for acetabular component orientation. QUESTIONS/PURPOSES: We measured the variation in pelvic tilt in 30 patients before THA and the effect of THA on pelvic tilt in the same patients more than a year after THA. METHODS: Each patient had a CT study for CT-based surgical navigation and standing and supine radiographs before and after surgery. Pelvic tilt was calculated for each of the radiographs using a novel and validated two-dimensional/three-dimensional matching technique. RESULTS: Mean supine pelvic tilt changed less than 2°, from 4.4° ± 6.4° (range, -7.7° to 20.8°) before THA to 6.3° ± 6.6° (range, -5.7° to 19.6°) after THA. Mean standing pelvic tilt changed less than 1°, from 1.5° ± 7.2° (range, -13.1° to 12.8°) before THA to 2.0° ± 8.3° (range, -12.3° to 16.8°) after THA. Preoperative pelvic tilt correlated with postoperative tilt in both the supine (r(2) = 0.75) and standing (r(2) = 0.87) positions. CONCLUSIONS: In this population, pelvic tilt had a small and predictable change after surgery. However, intersubject variability of pelvic tilt was high, suggesting preoperative pelvic tilt should be considered when determining desired acetabular component positioning on a patient-specific basis.