Incidence and Risk Factors for Hardware Removal Following Periacetabular Osteotomy and Its Association with Clinical Outcomes

Background: Periacetabular osteotomy (PAO) can be used for joint preservation in symptomatic developmental dysplasia of the hip (DDH) and femoroacetabular impingement (FAI). 1 of the most common procedures following PAO is hardware removal. The aims of this study were to determine the rate of hardware removal and patient characteristics associated with this outcome following PAO.

Methods: Data from a prospectively-collected registry was retrospectively reviewed at one institution managing DDH or FAI patients with PAO from July 2008-December 2015. Patients who completed preoperative and postoperative patient reported outcome (PRO) questionnaires with minimum 1-year follow-up were evaluated, resulting in 221 patients followed for a mean of 2.8 years (range 1.0-7.7 years). There were 80% women, mean age was 25 years and mean body mass index (BMI) was 25 kg/m. Fully-threaded 4.5-mm screws were used for internal fixation.

Results: Hardware removal occurred in 30 patients (13.6%) at a mean of 1.0 years after PAO. Patients undergoing hardware removal were younger (mean age 20.4 vs. 26.3 years), thinner (mean BMI 22.2 vs. 25.1), had less severe dysplasia (DDH patients only: mean lateral centre-edge angle 21.0 vs. 16.2, mean Tönnis angle 12.9 vs. 16.8), and were more likely to have PAO for FAI (33% vs. 11%) compared to patients with retained hardware. At final follow-up, multivariable analysis demonstrated a trend toward inferior patient reported outcomes in the hardware removal group.

Conclusions: This study defines the incidence and characteristics of patients undergoing hardware removal after PAO and demonstrates similar outcomes to patients who do not require hardware removal.