BACKGROUND It has been demonstrated biomechanically that 25% is a critical size defect of the glenoid. However, a recent clinical study reported that a bone loss between 13.5% and 20% (subcritical bone loss) led to impairment of quality of life but not a recurrence of instability. PURPOSE To clarify whether a subcritical bone loss exists in assessing a Hill-Sachs lesion via a disease-specific quality of life questionnaire. STUDY DESIGN Cohort study; Level of evidence, 3. METHODS Fifty patients (mean age, 27 years) with <25% glenoid defect who were treated with arthroscopic Bankart repair for recurrent anterior dislocation were assessed at a mean follow-up of 28 months. All had an on-track Hill-Sachs lesion. The Western Ontario Shoulder Instability Index (WOSI) and Rowe scores were used for the clinical evaluation. The Hill-Sachs interval was measured on 3-dimensional computed tomography images and divided by the glenoid track width, defined as the Hill-Sachs occupancy (in percentages). The glenoid track was divided into 4 zones based on the percentage of the Hill-Sachs occupancy: zone 1, <25%; zone 2, 25% to <50%; zone 3, 50% to <75%; and zone 4, ≥75%. RESULTS The recurrence rate was 6% (3 of 50 shoulders). The Rowe score significantly improved from 45.2 ± 4.7 (mean ± SD) preoperatively to 92.3 ± 6.5 at the final follow-up (P < .05). The WOSI score also significantly increased from 46.6% ± 19.3% preoperatively to 72.3% ± 21.0% at the final follow-up (P < .001). The WOSI score of patients in zone 4 (peripheral-track lesion) (n = 10) was significantly lower than those in the other zones (central-track lesion) (P = .0379). Of the 10 patients with the peripheral-track lesion, 5 had a <40% WOSI score, similar to the preoperative WOSI score (46.6%). CONCLUSION Patients with on-track lesions can be divided into 2 subgroups: those with the Hill-Sachs occupancy ≥75% (peripheral-track lesion) showed significantly worse WOSI score without recurrent instability events than those with the Hill-Sacks occupancy <75% (central-track lesion).

中文翻译：

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外围轨道和中央轨道山萨克斯病灶：评估病灶上病灶的新概念。

背景技术已经生物力学证明了25％是关节盂的关键尺寸缺陷。但是，最近的一项临床研究报告说，骨质流失介于13.5％和20％之间（亚临界骨质流失）会导致生活质量下降，但不会导致不稳定性的复发。目的通过特定于疾病的生活质量调查问卷来澄清评估Hill-Sachs病变时是否存在亚临界骨丢失。研究设计队列研究；证据等级，3。方法采用关节镜行Bankart修复治疗复发性前脱位的50例<25％关节盂缺损患者（平均年龄27岁），平均随访28个月。所有人都在赛道上有Hill-Sachs病灶。安大略省西部肩膀不稳定性指数（WOSI）和Rowe评分用于临床评估。在3维计算机断层扫描图像上测量Hill-Sachs间隔，并除以关节盂径迹宽度（定义为Hill-Sachs占用率（百分比））。根据Hill-Sachs的入住率，将关节盂轨迹分为4个区域：区域1，<25％；区域1，<25％。2区，从25％到<50％；3区，从50％到<75％；和4区，≥75％。结果复发率为6％（50例肩膀中有3例）。Rowe评分从术前的45.2±4.7（平均±SD）显着提高到最后一次随访时的92.3±6.5（P <.05）。最后一次随访时，WOSI评分也从术前的46.6％±19.3％显着提高到72.3％±21.0％（P <.001）。第4区（周围区域病变）（n = 10）患者的WOSI评分显着低于其他区域（中心区域病变）的患者WOSI评分（P = .0379）。在10例周围轨迹病变的患者中，有5例的WOSI得分<40％，与术前WOSI得分相似（46.6％）。结论伴有正向病变的患者可分为两个亚组：Hill-Sachs占位≥75％（周围性病变）的患者在没有复发性不稳定事件的情况下，WOSI评分显着低于Hill-Sacks占位<75％的患者。 （中央轨迹病变）。