Review Question - QID 214000

This patient sustained a native left acetabular fracture and underwent open reduction internal fixation (ORIF). Of the options in the question, the only protective factor against early conversion to total hip arthroplasty (THA) is his age, being less than 40 years.

The survival of the native hip after acetabular fracture ORIF is dependent on multiple factors including patient age (<40 years), fracture pattern (simple fractures), initial fracture displacement (<20 mm), quality of reduction, and absence of injury to the femoral head. While ORIF can be successful when these protective factors are present, osteopenia, pre-injury hip arthritis and significant chondral impaction injuries makes ORIF difficult and more prone to failure. In the elderly patient with these injury characteristics and/or delayed presentation, THA should be considered in the index procedure.

Liebergall et al. investigated the clinical outcomes of surgical treatment after acetabular fractures. They reported that patient age less than 40 years, simple type Letournel and Judet fractures, and absence of femoral head damage were statistically significant predictors of a successful outcome after ORIF. They concluded that ORIF of the displaced acetabular fracture can result in a satisfactory clinical outcome when these factors are present.

Tannast et al. investigated factors predicting conversion to THA or hip arthrodesis after ORIF of acetabular fractures. They reported that the significant independent negative predictors for early conversion to THA were nonanatomic fracture reduction, age >40 years, anterior hip dislocation, postoperative incongruence of the acetabular roof, posterior acetabular wall involvement, acetabular impaction, femoral head cartilage lesion, initial displacement of the articular surface of ≥ 20 mm, and utilization of the extended iliofemoral approach. They concluded that while ORIF was able to successfully prevent the need for subsequent THA within twenty years in 79% of their patients, the presence of the above factors warrants consideration for primary THA at the index procedure.

Figures A and B demonstrate an acetabular fracture. Figure C demonstrates this same acetabular fracture after ORIF.

Incorrect Answers:
Answer 1: A femoral head cartilage defect would be predictive (not protective) of early conversion to THA.
Answer 3: Gender has not been found to be a positive or negative predictor of early conversion to THA.
Answer 4: Initial displacement of >20 mm would be predictive (not protective) of early conversion to THA.
Answer 5: Utilization of the extended iliofemoral approach would be predictive (not protective) of early conversion to THA.