Kazuhiro Shibayama1, Hiroshi Iwaso2. 1. Department of Orthopedic Sports Surgery, Kanto Rosai Hospital, Kanagawa, Japan. Electronic address: kazuhiro04132001@yahoo.co.jp. 2. Department of Orthopedic Sports Surgery, Kanto Rosai Hospital, Kanagawa, Japan.
Abstract
BACKGROUND: The Hill-Sachs lesion (HSL) plays a role in recurrent glenohumeral joint instability. Currently, there are no studies based on the form characteristics of HSL. The purposes of this study were to report the HSL form characteristics and to determine whether they are correlated with number of prior subluxations and dislocations. METHODS: The study enrolled 134 consecutive patients diagnosed with anterior shoulder instability during an arthroscopic procedure. We classified the arthroscopic findings into 4 types, as follows: type 1, cyst type; type 2, gutter type; type 3, island type; and type 4, wide type. Subsequently, we investigated the correlation between each type and the number of shoulder subluxations and dislocations reported. The following data were analyzed: subluxation and dislocation history, arthroscopic findings, and maximum lesion size. RESULTS: Of the patients evaluated, 18, 32, 30, and 54 were classified as types 1 to 4, respectively. The mean numbers of shoulder dislocations were 3.3, 7.3, 6.0, and 12.0 for types 1 to 4, respectively. The wide type was correlated with more subluxations and dislocations than the other types (P = .001, .046, and .007, respectively). There were significant differences in mean width among all types (P < .0001). HSL width was correlated with lesion type and angle. CONCLUSION: We classified HSL into 4 types on the basis of visual inspection and found a correlation between lesion type and lesion size. However, HSL width was correlated with lesion type and angle; that is, the number of dislocations and subluxations does not affect HSL width.
BACKGROUND: The Hill-Sachs lesion (HSL) plays a role in recurrent glenohumeral joint instability. Currently, there are no studies based on the form characteristics of HSL. The purposes of this study were to report the HSL form characteristics and to determine whether they are correlated with number of prior subluxations and dislocations. METHODS: The study enrolled 134 consecutive patients diagnosed with anterior shoulder instability during an arthroscopic procedure. We classified the arthroscopic findings into 4 types, as follows: type 1, cyst type; type 2, gutter type; type 3, island type; and type 4, wide type. Subsequently, we investigated the correlation between each type and the number of shoulder subluxations and dislocations reported. The following data were analyzed: subluxation and dislocation history, arthroscopic findings, and maximum lesion size. RESULTS: Of the patients evaluated, 18, 32, 30, and 54 were classified as types 1 to 4, respectively. The mean numbers of shoulder dislocations were 3.3, 7.3, 6.0, and 12.0 for types 1 to 4, respectively. The wide type was correlated with more subluxations and dislocations than the other types (P = .001, .046, and .007, respectively). There were significant differences in mean width among all types (P < .0001). HSL width was correlated with lesion type and angle. CONCLUSION: We classified HSL into 4 types on the basis of visual inspection and found a correlation between lesion type and lesion size. However, HSL width was correlated with lesion type and angle; that is, the number of dislocations and subluxations does not affect HSL width.