Watarai Keisuke, Kimura Fumihiko, Kadono Yuho, Kim Yoon Taek, Niitsu Mamoru, Oda Hiromi, Azuma Hirohiko
Department of Orthopaedic Surgery, Saitama Medical University, 38 Morohongo, Moroyama-machi, Iruma-gun, Saitama, 350-0495, Japan.
Department of Radiology, Saitama Medical University, Saitama, Japan.
Clin Orthop Relat Res. 2017 Aug;475(8):2074-2080. doi: 10.1007/s11999-017-5381-y. Epub 2017 May 16.
Complete circumferential osseous extension in the acetabular rim has been reported to occur in the deep hip with pincer impingement. However, this phenomenon occasionally is observed in dysplastic hips without pincer impingement, and the degree to which this finding might or might not be associated with hip pain, and how often it occurs bilaterally among patients, are not well characterized.
QUESTIONS/PURPOSES: (1) To determine the proportion of patients with complete circumferential osseous extension in the acetabular rim using three-dimensional (3-D) CT in patients with and without hip pain who had CT scans obtained for various reasons. (2) To elucidate how often this complete circumferential osseous extension occurred bilaterally among those patients. (3) To investigate the relationship between the proportions of patients with complete circumferential osseous extension observed on CT scans among three different acetabular coverage groups: dysplasia, normal, and overcoverage. (4) To determine how often the finding of hip pain was associated with complete circumferential osseous extension.
Between September 2011 to July 2016, we evaluated 3788 patients with pelvic complaints such as hip, groin, thigh, buttock, or sacroiliac joint pain. We obtained consent from 26% (992 of 3788) of them, and obtained 3-D CT scans as part of that evaluation. For the current retrospective study, we excluded patients younger than 20 years or 80 years or older (181 patients), patients who had previous hip surgery (185 patients), patients with severe osteoarthritis with Tönnis Grades 2 or 3 (301 patients), and patients who could not have an accurate lateral center-edge (LCE) angle measured owing to poor-quality radiographs (24 patients), leaving 301 patients (602 hips) for this analysis. In this study population, patients reported pain in 131 hips (22%), defined as all types of hip pain except for trauma, including activity pain, pain with sports, pain on motion, and impingement pain; the others did not report hip pain. The mean age of the patients was 56 ± 16 years, and the mean LCE angle was 26° ± 8° (range, -9° to 47°). We first determined the proportion of patients with complete circumferential osseous extension in the acetabular rim using 3-D CT for those with and without hip pain who had CT obtained for various reasons. We next elucidated how often this complete circumferential osseous extension occurred bilaterally among the patients, and finally we investigated the relationship between the proportion of patients with complete circumferential osseous extension observed on CT scans among the three groups: dysplasia (defined as LCE angles of 22° or smaller), normal, and overcoverage (defined as LCE angles of 34° or larger) groups. We finally determined how often the finding was associated with hip pain attributable to complete circumferential osseous extension.
The proportion of patients with complete circumferential osseous extension was 6% (18 of 301 patients). Eighty-nine percent (16 of 18) of the patients had bilateral complete circumferential osseous extension. There were no differences in the proportions of patients with complete circumferential osseous extension among the three groups: 5.3% (odds ratio [OR], 1.02; 95% CI, 0.45-2.31; p = 0.97), 5.3%, and 7.4% (OR, 0.70; 95% CI, 0.28-1.73; p = 0.44) in the dysplasia, normal, and overcoverage groups, respectively, with the numbers available. Eighteen percent (six of 34) of the hips with complete circumferential osseous extension had pain.
Complete circumferential osseous extension in the acetabular rim is relatively uncommon. When it occurs, it usually is bilateral, it occurs regardless of acetabular coverage, and it is associated with pain in a minority of patients.
Level III, prognostic study.
据报道，髋臼边缘完全环形骨延伸在伴有钳夹撞击的髋关节深部出现。然而，这种现象偶尔也会在无钳夹撞击的发育不良髋关节中观察到，且该发现与髋关节疼痛的关联程度以及在患者中双侧出现的频率尚未得到充分描述。
问题/目的：（1）使用三维（3-D）CT确定因各种原因进行CT扫描的有或无髋关节疼痛患者中髋臼边缘完全环形骨延伸的患者比例。（2）阐明这些患者中双侧出现完全环形骨延伸的频率。（3）研究在三种不同髋臼覆盖组（发育不良、正常和覆盖过度）中，CT扫描观察到的髋臼边缘完全环形骨延伸患者比例之间的关系。（4）确定髋关节疼痛的发现与完全环形骨延伸相关的频率。
2011年9月至2016年7月期间，我们评估了3788例有骨盆相关症状（如髋部、腹股沟、大腿、臀部或骶髂关节疼痛）的患者。其中26%（3788例中的992例）患者同意参与，并作为评估的一部分进行了3-D CT扫描。对于当前的回顾性研究，我们排除了年龄小于20岁或大于80岁的患者（181例）、既往有髋关节手术史的患者（185例）、患有严重骨关节炎（Tönnis分级为2级或3级）的患者（301例）以及因X线片质量差无法准确测量外侧中心边缘（LCE）角的患者（24例），最终纳入301例患者（602个髋关节）进行分析。在该研究人群中，131个髋关节（22%）的患者报告有疼痛，疼痛定义为除创伤外的所有类型的髋关节疼痛，包括活动痛、运动痛、运动时疼痛和撞击痛；其他患者未报告髋关节疼痛。患者的平均年龄为56±1六岁，平均LCE角为26°±8°（范围为-9°至47°）。我们首先使用3-D CT确定因各种原因进行CT扫描的有或无髋关节疼痛患者中髋臼边缘完全环形骨延伸的患者比例。接下来，我们阐明这些患者中双侧出现完全环形骨延伸的频率，最后，我们研究三组（发育不良组（定义为LCE角≤22°）、正常组和覆盖过度组（定义为LCE角≥34°））中CT扫描观察到的髋臼边缘完全环形骨延伸患者比例之间的关系。我们最终确定该发现与完全环形骨延伸所致髋关节疼痛相关的频率。
髋臼边缘完全环形骨延伸的患者比例为6%（301例患者中的18例）。89%（18例中的16例）的患者双侧出现完全环形骨延伸。三组中髋臼边缘完全环形骨延伸的患者比例无差异：发育不良组为5.3%（优势比[OR]，1.02；95%可信区间[CI]，0.45 - 2.31；p = 0.97），正常组为5.3%，覆盖过度组为7.4%（OR，0.70；95%CI，0.28 - 1.73；p = 0.,44），每组有效病例数如上。髋臼边缘完全环形骨延伸的髋关节中有18%（34例中的6例）有疼痛。
髋臼边缘完全环形骨延伸相对少见。当出现时，通常为双侧，与髋臼覆盖情况无关，且仅在少数患者中与疼痛相关。
III级，预后研究。
