2015 ISAKOS Biennial Congress ePoster #2308

Analysis of Risk Factors for Hill-Sachs Lesion in Anterior Shoulder Instability

Motoki Tanaka, MD, Fukuoka, Fukuoka JAPAN
Koichiro Tanaka, MD, PhD, Fukuoka, Fukuoka JAPAN
Kazutomo Onishi, MD, Funabashi, Chiba JAPAN
Morihito Tokai, MD, Funabashi, Chiba JAPAN
Nobuaki Kawai, MD, Kushiro-Shi, Hokkaido JAPAN
Norimasa Takahashi, MD, Funabashi, Chiba JAPAN
Akimoto Nimura, MD, PhD, Tokyo JAPAN
Hiroyuki Sugaya, MD, Funabashi, Chiba JAPAN

Funabashi Orthopedic Hospital Shoulder and Elbow center , Funabashi , Chiba , JAPAN

FDA Status Not Applicable

Summary: We investigated the association between the risk factors and size of Hill-Sachs lesion.

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Abstract:

Purpose

It’s vitally important for patients with anterior shoulder instability to evaluate the risk factors of the post-operative dislocation. Although we’ve performed the Hill-Sachs Remplissage procedure as a reinforcement for high risk cases, the size of Hill-Sachs lesions (HSL) as one of the indications of this procedure haven’t been evaluated quantitatively. The purpose of this study is to assess the size of HSL quantitatively and to investigate the association between HSL and the risk factors of anterior shoulder instability.

Materials And Methods

After approval of IRB for this study and the informed consent 90 patients who underwent a primary arthroscopic stabilization in single shoulder for traumatic anterior glenohumeral instability were eligible in this retrospectively study. These included 71 males and 19 females with an average age of 26.9 years at the time of operation. We calculated the ratio between both the maximum values of the width or the depth and the maximum diameter of the humeral heads using computed tomography. Based on these results, the reallocation of the ratio of width and depth were used by S.D. in normal distribution and we classified the size of HSL into three categories by width (small: <38%,medium: 38%?width?48%, large: 48%<) and depth (shallow: <12%,medium: 12%?depth?17%,deep: 17%<) and investigated the relationship between these sizes and the presence or absence of bony Bankart lesions, the number of dislocations, age, sex and athletic career. HSLs were divided into two groups using our classification, Group 1 consisted of size whether it was small width or shallow depth and Group 2 consisted of size whether it was more than medium width or depth. We assessed two groups about each risk factors.
The Fleiss coefficient was calculated to determine the interobserver reliability.

Results

Of the category of width, there are 21 in small, 38 in medium and 31 in large. The number of dislocations was significantly higher in the large size than that of the small size and the large size consisted of the high energy sports more significantly than the small size. Of the category of depth, there are 28 in shallow, 53 in medium and 9 in deep. Although there were no significant difference between the depth of HSL and each risk factors, the presence of bony Bankart lesions and the number of high energy sports career were significantly greater in Group 2 than in Group 1.
Conclusion:As the width became larger, the number of dislocations significantly increased. When the width and the depth were over the medium-size, they had more significantly bony Bankart lesions and high energy sports.