Orthopaedic Trauma Service, Hospital for Special Surgery and New York Presbyterian Hospital, Weill Cornell Medicine, New York, NY, USA.
Trauma Research Unit, Department of Surgery, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands.
Arch Orthop Trauma Surg. 2019 Dec;139(12):1667-1672. doi: 10.1007/s00402-019-03192-w. Epub 2019 Apr 27.
Computed tomography (CT) is more accurate than plain pelvic radiography (PXR) for evaluating acetabular fracture reduction. As yet unknown is whether CT-based assessment is more predictive for clinical outcome. We determined the independent association between reduction quality according to both methods and native hip survivorship following acetabular fracture fixation.
Retrospectively, 220 acetabular fracture patients were reviewed. Reductions on PXR were graded as adequate or inadequate (0-1 mm or > 1 mm displacement) (Matta's criteria). For CT-based assessment, adequate reductions were defined as < 1 mm step and < 5 mm gap, and inadequate reductions as ≥ 1 mm step and/or ≥ 5 mm gap displacement. Predictive values and Kaplan-Meier hip survivorship curves were compared and risk factors for conversion to total hip arthroplasty (THA) were identified.
Mean follow-up was 8.9 years (SD 5.6, range 0.5-23.3 years), and 52 patients converted to THA (24%). Adequate reductions according to CT versus PXR assessment were associated with higher predictive values for native hip survivorship (92% vs. 82%; p = 0.043). Inadequate reductions were equally predictive for conversion to THA (33% for CT and 30% for PXR; p = 0.623). For both methods, survivorship curves of adequate versus inadequate reductions were significantly different (p = 0.030 for PXR, p < 0.001 for CT). Only age ≥ 50 years (p < 0.001) and inadequate reductions as assessed on CT (p = 0.038) were found to be independent risk factors for conversion to THA. Reduction quality as assessed on PXR was not found to be independently predictive for this outcome (p = 0.585).
Native hip survivorship is better predicted based on postoperative CT imaging as compared to PXR assessment. Predicting need for THA in patients with inadequate reductions based on both assessment methods remains challenging. While both PXR and CT-based methods are associated with hip survivorship, only an inadequate reduction according to CT assessment was an independent risk factor for conversion to THA.
与骨盆平片（PXR）相比，计算机断层扫描（CT）在评估髋臼骨折复位方面更为准确。目前尚不清楚基于 CT 的评估是否对临床结果更具预测性。我们确定了根据这两种方法评估的复位质量与髋臼骨折固定后髋关节自然生存率之间的独立关联。
回顾性分析 220 例髋臼骨折患者。通过 PXR 评估，将复位分为充分或不充分（0-1mm 或 >1mm 移位）（Matta 标准）。对于基于 CT 的评估，充分的复位定义为 <1mm 台阶和 <5mm 间隙，不充分的复位定义为≥1mm 台阶和/或≥5mm 间隙移位。比较了预测值和 Kaplan-Meier 髋关节生存率曲线，并确定了转换为全髋关节置换术（THA）的危险因素。
平均随访时间为 8.9 年（标准差 5.6，范围 0.5-23.3 年），52 例患者转为 THA（24%）。与 PXR 评估相比，根据 CT 评估的充分复位与髋关节自然生存率的预测值更高（92% vs. 82%；p=0.043）。两种方法中，不充分复位对转换为 THA 的预测值相同（CT 为 33%，PXR 为 30%；p=0.623）。对于这两种方法，充分复位与不充分复位的生存率曲线差异均有统计学意义（PXR 为 p=0.030，CT 为 p<0.001）。只有年龄≥50 岁（p<0.001）和 CT 评估的不充分复位（p=0.038）被发现是转换为 THA 的独立危险因素。PXR 评估的复位质量未被发现是该结果的独立预测因素（p=0.585）。
与骨盆平片评估相比，基于术后 CT 成像的髋关节自然生存率预测更好。根据两种评估方法，对不充分复位患者预测需要 THA 仍然具有挑战性。虽然 PXR 和 CT 两种方法都与髋关节生存率相关，但只有 CT 评估的不充分复位是转换为 THA 的独立危险因素。
