The CU PAO: A Minimally Invasive, 2-Incision, Interlocking Periacetabular Osteotomy: Technique and Early Results.

BACKGROUND: The aims of this study were to describe a novel minimally invasive, interlocking periacetabular osteotomy (PAO) for the treatment of hip dysplasia that was developed at our institution and to report on its safety, complications, and early clinical outcomes. METHODS: This was a prospective longitudinal study of the first 200 consecutive hips that underwent the CU (University of Colorado) PAO, an interlocking osteotomy combining the benefits of the Birmingham interlocking pelvic osteotomy (BIPO) and the Ganz PAO. The technique provides direct visualization of the sciatic nerve during the ischial osteotomy and allows for immediate weight-bearing postoperatively. Demographic characteristics, intraoperative and perioperative parameters, and functional outcomes were documented. All patients underwent hip arthroscopy 3 to 10 days prior to the PAO to address concomitant intra-articular pathology. Mechanical deep venous thrombosis (DVT) prophylaxis was used for 2 weeks postoperatively. Results were stratified to compare the first 100 and the second 100 cases. RESULTS: A total of 161 patients (200 hips) underwent primary PAO; mean follow-up was 20 months (range, 3 to 33 months). The mean patient age at the time of surgery was 29.4 years (range, 13 to 55 years). Females accounted for 89% of the patients included in this study. The average length of stay was 4 days. A concomitant proximal femoral derotational osteotomy was performed in 19 hips. The lateral center-edge angle (LCEA) improved from a mean of 18.8° preoperatively to 31.5° postoperatively (p < 0.001). The mean Non-Arthritic Hip Score (NAHS) improved from 56.0 preoperatively to 89.4 at the 24-month follow-up (p < 0.0001). Paresthesias in the distribution of the lateral femoral cutaneous nerve were common (65% at 2 weeks postoperatively) but resolved in 85% of the patients within the first 6 months. There were no sciatic nerve-related complications, deep infections, or DVTs. CONCLUSIONS: The CU PAO enables corrective realignment of symptomatic acetabular dysplasia with direct visualization of the sciatic nerve, early weight-bearing, cosmetic incisions, and good short-term outcomes. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.