# Complications, Conversion, and Secondary Procedures Following Minimally Invasive Periacetabular Osteotomy: A Single-Surgeon Case Series

## TL;DR

This study examines outcomes of minimally invasive hip surgery, finding that factors like BMI and age affect complication and conversion rates.

## Contribution

The study identifies specific patient risk factors for poor outcomes following minimally invasive periacetabular osteotomy.

## Key findings

- Complication rate was 6.2%, with higher BMI, smoking, and age linked to increased risk.
- 10.9% of patients required secondary procedures, increasing to 17.2% at 10 years.
- 3.7% of patients needed conversion to total hip arthroplasty within a mean of 4.6 years.

## Abstract

The introduction of minimally invasive periacetabular osteotomy (PAO) has reduced complications, allowing a broader range of patients to be considered for the procedure. This study aimed to identify patient-specific risk factors for poor outcomes.

This retrospective case series (n = 513) used data from a local hip registration registry. Isolated PAOs with at least 1-year follow-up were included. Electronic records were reviewed to extract demographics and variables. The primary outcome was complication rate, with secondary outcomes including secondary procedures and conversion to total hip arthroplasty. Logistic regression was performed to correlate independent variables to outcomes, and Kaplan-Meier analysis assessed the survival of the native hip and cumulative complication risk.

Complication rate was 6.2%. Higher body mass index (BMI), smoking, Tönnis grade 2, and increasing age were associated with higher odds of complications (P < .05). The nonunion rate was 4.3%; higher BMI and age linked to increased risk (P < .05). 10.9% of patients required a secondary procedure and cumulative risk for secondary procedures at 5 years was 11.4% and at 10 years was 17.2%. BMI correlated with the need for secondary procedures (P = .001). 3.7% (n = 19) required conversion to total hip arthroplasty with a mean time to conversion of 4.6 years ±2.04. The 5- and 10-year survival rates were 96.3 and 92.7%, respectively.

Minimally invasive PAO has acceptable rates of complication and conversion at mid-term follow-up. Age, BMI, smoking status, and Tönnis grade 2 are associated with inferior outcomes. Knowledge of patient-specific risk factors can help in decision-making, expectation setting, and perioperative interventions.