How to minimize complications during and after periacetabular osteotomy : lessons learned from over 700 patients with and without concomitant hip arthroscopy

Abstract

Aims: Periacetabular osteotomy (PAO) is a complex procedure for treating hip dysplasia by reorienting the acetabulum to slow osteoarthritis progression. This study aimed to assess the types and rates of complications after PAO and provide recommendations for prevention.

Methods: A total of 715 consecutive patients underwent unilateral PAO by a single surgeon between December 2006 and January 2024, with at least one year of follow-up. Indications included hip dysplasia, acetabular retroversion, and protrusio. Hip arthroscopy was performed concurrently in 325 cases. Demographic factors, perioperative data, and complications - graded using the modified Clavien-Dindo system - were analyzed. Risk factors and learning curves were also assessed.

Results: Of the 715 patients, 121 (16.6%) experienced 144 complications. There were 68 grade I, 52 grade II, 23 grade III, one grade IV, and 0 grade V complications. The 23 grade III complications requiring reoperations included four revision PAOs for overcorrection, three fixations for posterior column fracture, four neurolysis procedures for symptomatic lateral femoral cutaneous nerve (LFCN) dysesthesias, four heterotopic bone excisions, and eight wound debridements. All type I and II complications were treated without sequelae. The addition of hip arthroscopy did not increase complication rates. Age < 20 years was associated with a lower risk of complications (odds ratio (OR) = 0.53, 95% CI 0.33 to 0.84, p = 0.008), whereas smoking history (OR = 1.72, 95% CI 1.01 to 2.87, p = 0.040) and correction of both acetabular dysplasia and retroversion (OR = 2.46, 95% CI 1.08 to 5.24, p = 0.024) were linked to an increased risk of complications. The operating time and incidence of complications decreased with increasing experience.

Conclusion: PAO is an effective procedure with an acceptable complication rate. Risk factors should be discussed during preoperative counselling. While patient optimization may help to reduce complications, precise intraoperative technique remains critical for minimizing risk.

Fig. 1

a) Illustration highlighting the importance of confirming the completion of the iliac posterior-lateral osteotomy before advancing to the posterior column osteotomy. b) Incomplete posterior-lateral iliac osteotomy can impede propagation toward the ischial osteotomy, potentially requiring forceful mobilization of the acetabular fragment or additional osteotomy passes. c) Illustration demonstrating the use of a Schanz pin and sharp bone hook to mobilize the acetabular fragment. The Schanz pin is positioned under fluoroscopic guidance to ensure alignment parallel to the ischial osteotomy and prevent unintended cutting into the iliac osteotomy. Mobilization of the fragment with the Schanz pin follows a counterclockwise rotation for the right hip and a clockwise rotation for the left hip. A sharp bone hook is used at the pubic osteotomy site to facilitate fragment mobilization and prevent hinged correction, particularly when resistance to rotation occurs.

Fig. 2

a) The median operating time for periacetabular osteotomy (PAO), along with the IQR, significantly decreased across the patient groups, as demonstrated by the Kruskal-Wallis test (p < 0.001). b) The trend of complications in periacetabular osteotomy across patient groups. The total number of complications (black bars), Clavien-Dindo grade III and IV complications (grey bars), and cases of overcorrection or undercorrection (white bars) are shown for each case group. A significant decrease in the total number of complications was observed with increasing case numbers, as demonstrated by Fisher’s exact test (p = 0.004). Additionally, there is a noticeable trend towards a reduction in overcorrection or undercorrection with increased experience.