Du Yin-Qiao, Sun Jing-Yang, Ma Hai-Yang, Wang Sen, Ni Ming, Zhou Yong-Gang
Department of Orthopaedics, General Hospital of Chinese People's Liberation Army, Beijing, China.
Orthop Surg. 2020 Jun;12(3):749-755. doi: 10.1111/os.12667. Epub 2020 Mar 31.
To explore the leg length balance in total hip arthroplasty (THA) with shortening subtrochanteric osteotomy (SSTO) or not for unilateral Crowe type IV developmental dysplasia of the hip (DDH) through the evaluation of postoperative full-length anteroposterior radiographs.
The postoperative radiographs of 60 patients with unilateral Crowe type IV DDH from July 2012 to May 2019 were retrospectively reviewed. All patients underwent THA using the Pinnacle Acetabular Cup system, a ceramic liner and femoral head, and the S-ROM stem with a proximal sleeve or cone. Patients with leg length discrepancy (LLD) < 10 mm were defined as the non-LLD group. To identify differences associated with SSTO, the group was further divided into two groups based on whether the patient underwent SSTO. A total of 48 patients (26 for SSTO and 22 for non-SSTO) were in the non-LLD group. There were 3 male and 45 female patients. The mean age of the patients in the non-LLD group was 39 years. These data, including leg length, femoral length, the height of center of rotation (COR) of the hip, the depth of the sleeve or cone in the femoral medullary canal and the height of the greater trochanter, were measured.
In the non-LLD group, the femoral lengths in both SSTO and non-SSTO groups were significantly shorter on the operated side compared with the contralateral side, and the mean discrepancy in the SSTO group was approximately equal to the mean length of the SSTO. The mean height of the COR of the hip on the operated sides in both SSTO and non-SSTO groups was 13.2 mm, and the contralateral sides were 15.2 and 15.5 mm, respectively. The depth of the sleeve or cone in the femoral medullary canal between SSTO and non-SSTO groups was 21.7 and 30.6 mm, respectively. The depth of the sleeve or cone in the SSTO group was negatively correlated with the length of SSTO. The heights of the greater trochanter in the operated and contralateral sides were 5.3 and 16.6 mm in the SSTO group, and 13.2 and 17.2 mm in the non-SSTO group, respectively.
Shortening subtrochanteric osteotomy led to femoral shortening on the operated side for patients with unilateral Crowe type IV DDH. The position of the sleeve or cone should be close to the apex of the greater trochanter to compensate the length of the SSTO. The position of the sleeve or cone without SSTO should be adjusted to make sure that the height of the greater trochanter on the operated side is close to that on the contralateral side.
通过评估术后全下肢前后位X线片，探讨在单侧Crowe IV型发育性髋关节发育不良（DDH）的全髋关节置换术（THA）中采用或不采用转子下缩短截骨术（SSTO）时的下肢长度平衡情况。
回顾性分析2012年7月至2019年5月期间60例单侧Crowe IV型DDH患者的术后X线片。所有患者均使用Pinnacle髋臼杯系统、陶瓷内衬和股骨头以及带有近端套筒或锥度的S-ROM柄进行THA。下肢长度差异（LLD）<10 mm的患者被定义为非LLD组。为了确定与SSTO相关的差异，根据患者是否接受SSTO将该组进一步分为两组。非LLD组共有48例患者（SSTO组26例，非SSTO组22例）。其中男性3例，女性45例。非LLD组患者的平均年龄为39岁。测量了这些数据，包括下肢长度、股骨长度、髋关节旋转中心（COR）高度、股骨髓腔内套筒或锥度的深度以及大转子高度。
在非LLD组中，SSTO组和非SSTO组手术侧的股骨长度均明显短于对侧，SSTO组的平均差异约等于SSTO截骨的平均长度。SSTO组和非SSTO组手术侧髋关节COR的平均高度分别为13.2 mm，对侧分别为15.2 mm和15.5 mm。SSTO组和非SSTO组股骨髓腔内套筒或锥度的深度分别为21.7 mm和30.6 mm。SSTO组套筒或锥度的深度与SSTO的长度呈负相关。SSTO组手术侧和对侧大转子的高度分别为5.3 mm和16.6 mm，非SSTO组分别为13.2 mm和17.2 mm。
对于单侧Crowe IV型DDH患者，转子下缩短截骨术导致手术侧股骨缩短。套筒或锥度的位置应靠近大转子顶点以补偿SSTO的长度。对于未行SSTO的情况，应调整套筒或锥度的位置，以确保手术侧大转子的高度接近对侧。
