20-YEAR SURVIVORSHIP OF THE HIP AFTER FIXATION OF ACETABULAR FRACTURES

Abstract

The ultimate goal of surgery for acetabular fractures is hip joint preservation for the rest of the patient’s life. However, besides Letournel’s series, long term survi-vorship in this predominantly young patient group has never been published in a very large series. The aim of this study was to determine the cumulative 20-year sur-vivorship of the hip after fixation of acetabular fractures and to identify factors predicting the need for total hip arthroplasty.

A Kaplan-Meier survivorship analysis of 1218 consecutive surgically treated acetabular fractures was carried out. 816 fractures were available for analysis with a mean follow up of 10.3 years (range 2–29 years). All the surgeries were performed by a single surgeon in accordance to an established treatment protocol based on Letournel’s principles. Inclusion criteria were a minimum follow-up of two years or failure at any time. Failure was defined as conversion to total hip arthroplasty of hip arthrodesis. A Cox-regression analysis identified significant risk factors predicting the need for total hip arthroplasty. Analyzed parameters comprised data on patient history, preoperative clinical examination, associated injuries, fracture pattern, radiographic and intra-operative features, and the accuracy of reduction.

The cumulative 20-years survivorship was 79% (95% CI, 76–81%). Statistically significant factors influencing the need for artificial hip replacement/arthrodesis were: age over 40 years (Hazard ratio [HR] 2.4), femoral head damage (HR 2.6), acetabular impaction (HR 1.5), postoperative incongruence of the acetabular roof (2.9), involvement of the posterior wall (HR 1.6), anterior dislocation (5.9), initial displacement > 20mm (HR 1.6), and a malreduction with residual displacement > 1mm (HR 3.0). There was a significantly different survivorship of the individual fracture types. The worst survivorship occurred in anterior wall fractures (34% at 20 years) and the best survivorship in both column fractures (87% at 20 years). The accuracy of reduction improved significantly over time.

In summary, the hip joint can be successfully preserved and prosthetic replacement avoided in 79% of displaced acetabular fractures at 20 years. Many of the factors influencing the long term prognosis are already determined at the time of injury. The factors that can be influenced by the surgeon are anatomic reduction, achievement of congruency of the acetabular roof and correction of marginal impaction. The presented unique results even exceed Letournel’s series in size and follow up. Therefore, they provide benchmark data for any type of comparative evaluation studies dealing with surgical treatment of acetabular fractures in future.