Offset correction via the Hueter approach effectively eliminates the pistol grip deformity in dysplastic hips undergoing periacetabular osteotomy

Abstract

Objectives

Large posterolateral CAM deformities represent a technically challenging entity due to the posterior location of the asphericity at the head–neck junction. The aim of this study was to determine whether access to the posterior CAM is improved in patients with concomitant hip dysplasia via a Hueter approach. It was hypothesized that an arthrotomy prior to periacetabular osteotomy (PAO) via the Hueter approach would allow for the elimination of the pistol-grip deformity in dysplastic hips.

Methods

A single-surgeon series of 342 PAOs performed between June 2023 and May 2025 was retrospectively assessed. Seventeen hips with dysplasia and a concomitant pistol-grip deformity were identified. Preoperative and postoperative measures of global femoral-head coverage (lateral center-edge angle, acetabular index, extrusion index, anterior and posterior wall indices) and femoral offset (anteroposterior and axial α-angles) were collected. The elimination of the pistol-grip deformity was confirmed independently by two observers. A matched cohort of isolated-PAO hips served to compare surgical time.

Results

There were only 17 (4.97%) dysplastic hips undergoing PAO with a concomitant pistol-grip deformity, indicating that this is a rather rare combination of pathologies. Of these, 11 (64.71%) were male. The femoral offset correction performed via the Hueter approach effectively restored a physiological offset as shown by a statistical significant reduction in the α-angle on anteroposterior (88.51 ​± ​13.17° to 60.86 ​± ​16.24°, p ​< ​0.0001) and axial (82.49 ​± ​10.37° to 51.31 ​± ​11.21°, p ​< ​0.0001) radiographs. The pistol-grip deformity was completely eliminated in all 17 hips. The combined procedure of PAO and femoral offset correction required statistical significantly more surgical time than isolated PAO (101.06 ​± ​21.34 ​min vs. 56.06 ​± ​16.75 ​min; p ​< ​0.0001).

Conclusions

These findings demonstrate that, in dysplastic hips, excellent access to the posterolateral CAM lesion characteristic of the pistol-grip deformity can be achieved. The posterior CAM deformity can be corrected through an arthrotomy via the Hueter approach, making use of the acetabular undercoverage to correct the posterior CAM, prior to performing the reorientation to correct dysplasia.

Level of Evidence

Level IV.