Outcomes of Posterior Wall Fractures of the Acetabulum Treated Nonoperatively After Diagnostic Screening with Dynamic Stress Examination Under Anesthesia

Abstract

Hip joint stability determined with dynamic stress fluoroscopy with the patient under general anesthesia after a posterior wall acetabular fracture is predictive of hip joint congruity, an excellent radiographic outcome, and a good-to-excellent early clinical outcome after nonoperative treatment.

Classifications in Brief: Letournel Classification for Acetabular Fractures

“…The integrity of the posterior capsule may be responsible for this retained stability [22]. Others have suggested hip stability can only be assessed with intraoperative fluoroscopy and patients generally do well, with or without surgery, as long as the hip is stable [5,21]. However, biomechanical studies have found joint reaction forces increase as the size of the posterior wall fracture increases, leading to concern regarding longterm results [16].…”

Can Computed Tomography Predict Hip Stability in Posterior Wall Acetabular Fractures?

“…However, none of the previous investigators has considered hip dislocation as part of the CT evaluation protocol. In addition, associated hip dislocation is reportedly not an important risk factor for residual instability of the hip [4].…”

“…Some investigators have described methods of predicting hip stability based on the size of the posterior wall fracture fragment as determined by 2-D CT [3,4,12,20]. Moed et al [13] recently compared hip stability status predictions using the method described by Calkins et al [3], the method described by Keith et al [5], and an alternative method [13].…”

“…These patients with isolated unilateral posterior wall (OTA 62-A1) [10] acetabular fractures had undergone dynamic stress fluoroscopy EUA to determine hip stability as described by Grimshaw and Moed [4] and Moed et al [13]. The use of EUA identified four stable hips and six unstable hips.…”

“…or loss of joint parallelism, is indicative of dynamic hip instability [2,5,[13][14][15][17][18][19][20][21], and EUA is considered the gold standard for diagnosis of dynamic hip stability status [4,13,18,19]. However, EUA has not attained general clinical use status, and CT assessment of fragment size and position is thought to be able to identify clinically unstable hips requiring operative fixation [3,5,13].…”