[Long-term results after acetabular fractures with respect to heterotopic ossifications]

Arthrosis, necrosis of the femoral head and heterotopic ossification (HO) tend to decline the outcome of acetabular fractures despite of good fracture reduction. In this study functional outcome and degree of HO were analyzed due to fracture type and surgical approach. The aim of this study is to delineate wether minimization of soft tissue damage increases the functional outcome.

55 patients with surgically treated acetabular fractures (mean age: 40.4 (20-81) years, male 43, female 12) where retrospectively evaluated with a mean follow-up of 7.7 (4.4-12.3) years. Fractures were classified according to the Orthopaedic Trauma Association (OTA), functional outcome was scored by D'Aubigné-Postel and the degree of HO was defined by Brooker's classification.

Following the OTA the distribution of fractures was: A-24 (44 %), B-23 (42 %) and C-8 (15 %). Mean D'Aubigné Index (max. 18 points) was 15.2, distributed to fracture type: A-15.9, B-15.0 and C-13.6. 32 % of all heterotopic ossifications were classified as Brooker 0, 10 % as Brooker 1, 29 % as Brooker 2 and Brooker 3 each, whereas Brooker 4 ossifications were not observed. 2/3 of the severe ossifications were observed using extended approaches or in case of type C fractures. The iliofemoral approach showed the tendency of fewer ossifications compared to extended approaches.

Decrease of soft tissue damage during acetabular surgery plays an important role to improve outcome. Due to the higher risk of wrong implant position and insufficient reduction using a soft tissue sparing approach, we recommend a CT scan postoperatively to evaluate reduction and osteosynthesis.