Results after surgical treatment of transtectal transverse acetabular fractures.

Objective: To retrospectively evaluate the results of operative treatment of transtectal transverse fractures of the acetabulum.

Methods: From May 1990 to July 2006, 40 patients with displaced transtectal transverse fracture of the acetabulum were treated surgically. A mean postoperative follow-up of 88.6 months' (range, 16-121 months) was achieved in 37 patients. Final clinical results were evaluated by a modified Merle d'Aubigné and Postel grading system. Postoperative radiographic results were evaluated by the Matta criteria. Fracture and radiographic variables were analyzed to identify possible associations with clinical outcome.

Results: Fracture reduction was graded as anatomic in 31 patients, imperfect in 4 and unsatisfactory in 2. Two hips were diagnosed to have subtle instability by postoperative radiography. The clinical outcome was graded as excellent in 16 patients, good in 14, fair in 4 and poor in 3. The radiographic result was graded as excellent in 14 patients, good in 15, fair in 4 and poor in 4. There was a strong association between the final clinical and radiographic outcomes. Variables identified as risk factors for unsatisfactory results included residual displacement greater than 2 mm, comminuted fracture of the weight bearing dome, postoperative subtle hip instability and damage to the cartilage of the femoral head.

Conclusion: The uncomplicated radiographic appearance of transtectal transverse fracture belies its complexity. Comminuted fracture of the weight bearing dome, unsatisfactory fracture reduction, subtle hip instability and damage to the cartilage of the femoral head are risk factors for the clinical outcome of transtectal transverse fracture of the acetabulum.