The Bristow procedure provides good midterm outcomes for competitive collision athletes, while postsurgical reinjury, the number of preoperative dislocations and subluxations, and large bone defects negatively affect postsurgical shoulder function. This information may be useful for treatment of shoulder dislocations in collision athletes.

ObjectivesTo characterise the tackler’s head position during one-on-one tackling in rugby and to determine the incidence of head, neck and shoulder injuries through analysis of game videos, injury records and a questionnaire completed by the tacklers themselves.MethodsWe randomly selected 28 game videos featuring two university teams in competitions held in 2015 and 2016. Tackles were categorised according to tackler’s head position. The ‘pre-contact phase’ was defined; its duration and the number of steps taken by the ball carrier prior to a tackle were evaluated.ResultsIn total, 3970 tackles, including 317 (8.0%) with the tackler’s head incorrectly positioned (ie, in front of the ball carrier) were examined. Thirty-two head, neck or shoulder injuries occurred for an injury incidence of 0.8% (32/3970). The incidence of injury in tackles with incorrect head positioning was 69.4/1000 tackles; the injury incidence with correct head positioning (ie, behind or to one side of the ball carrier) was 2.7/1000 tackles. Concussions, neck injuries, ‘stingers’ and nasal fractures occurred significantly more often during tackles with incorrect head positioning than during tackles with correct head positioning. Significantly fewer steps were taken before tackles with incorrect head positioning that resulted in injury than before tackles that did not result in injury.ConclusionTackling with incorrect head position relative to the ball carrier resulted in a significantly higher incidence of concussions, neck injuries, stingers and nasal fractures than tackling with correct head position. Tackles with shorter duration and distance before contact resulted in more injuries.

Background: Although surgical shoulder stabilization via coracoid transfer in collision athletes is effective and has a low reinjury rate, the factors affecting poor clinical results and the superiority of the 2 stabilization procedures (Bristow and Latarjet) remain unclear. Purpose: To explore the factor(s) affecting poor clinical results of coracoid transfer in a large cohort of rugby players and to compare postoperative function between the Bristow and Latarjet procedures. Study Design: Cohort study; Level of evidence, 3. Methods: This study included 169 consecutive shoulders of 154 competitive male rugby players who underwent shoulder stabilization surgery (Bankart repair with coracoid transfer) between 2014 and 2018 and had a mean follow-up of 2.7 years (minimum follow-up, 2 years). The Bristow procedure was performed in the first 92 shoulders (84 players), and the Latarjet procedure was performed in the latter 77 shoulders (70 players). A poor clinical result was defined as a postoperative Rowe score of <70 and a postoperative Western Ontario Shoulder Instability Index (WOSI) score of >630. Multiple logistic regression analysis was conducted to identify the factors affecting postoperative functional failure. The postoperative scores and complication rates were also compared between the 2 procedures. Results: In total, 92.3% of the rugby players returned to their preinjury competition level at a mean of 5.9 months postoperatively. The Rowe and WOSI scores showed that shoulder function was improved postoperatively compared with preoperatively. The number of rugby players with a poor clinical result was 18 (10.7%). Multiple logistic regression analysis demonstrated that a poor clinical result was associated with a preoperative glenoid bone defect of >20% of the glenoid width (odds ratio, 9.8), whereas the clinical result was unaffected by the type of coracoid transfer. There were no differences between the 2 procedures in any of the postoperative scores or complication rates. Conclusion: The present study indicated that the most effective predictor of postoperative functional scores was the degree of the glenoid bone defect and not the type of coracoid transfer. This information may be useful for the strategic treatment of shoulder dislocations in collision athletes.

Background: The size of a glenoid bone defect is responsible for reduction in shoulder stability and is correlated with the number of instability events. Biomechanical studies have suggested that it should be considered concomitantly with the Hill-Sachs lesion as “bipolar” bone defects for assessing structural degradation, but the definitive number of instability events associated with the critical size has not been investigated. Purpose: To (1) confirm that the number of instability events is the predictor of a critical size of bipolar bone defects and (2) demonstrate the cutoff value of the number of instability events for these defects in rugby players with traumatic anterior shoulder instability. Study Design: Cross-sectional study; Level of evidence, 3. Methods: One-hundred forty-four rugby players with anterior shoulder instability underwent morphologic evaluation for glenoid and Hill-Sachs lesions by computed tomography and determination of the critical (a glenoid bone defect of ≥25% or an off-track Hill-Sachs lesion) and subcritical (a glenoid bone defect of ≥13.5%) size of bipolar bone defects. In the primary analysis, the prevalence of the critical and subcritical size of bipolar bone defects was investigated. In the secondary analysis, the authors explored the predictors for these bone defects and determined the cutoff value correlating with the critical and subcritical size of bipolar bone defects by applying receiver operating characteristic curves. Results: The primary analysis revealed that the prevalence of critical and subcritical size of bipolar bone defects was 20.8% and 61.8% of 144 shoulders, respectively. In the secondary analysis, multiple logistic regression analysis demonstrated that the total number of shoulder instability events and dominant shoulder were the significant factors associated with the critical and subcritical size of bipolar bone defects. The cutoff value for the number of instability events that correlated with critical bipolar bone defects was 6 for the dominant and 9 for the nondominant shoulder, whereas it was 4 for the dominant and 5 for the nondominant shoulder for subcritical bipolar bone defects. Conclusion: The number of shoulder instability events and the dominant shoulder were the predictors for the critical and subcritical size of bipolar bone defects for a shoulder with traumatic instability. Four injury events should herald caution when treating rugby players with shoulder instability.

Objectives: To examine the effects of (1) trunk constraint and (2) the entry angle on the cervical spine in response to a headfirst impact. Materials:The AM50 Total HUman Model for Safety (THUMS ® ) v4.02, pedestrian finite element model, was subjected to head-first impacts. Methods:The impact speed was 3.2 m/s. The following patterns were simulated: entry angle (0°, 15°to the sagittal plane) and trunk constraint (constraint, unconstraint). Results: As a result of head-first impact, the upper cervical spine was extended and the lower cervical spine was markedly flexed when the trunk was constrained. The mean stress applied to the cervical spine was significantly increased when the trunk was constrained, as indicated by the Mann-Whitney U test. Conclusions:In a head-first impact, the mean stress on the cervical spine increases significantly when the trunk is constrained. In order to reduce the risk of cervical spine injuries, it is desirable not to bind with teammates before a head-first impact.