Young men in sports are at highest risk of acromioclavicular joint injuries: a prospective cohort study.

PURPOSE: To study the incidence of acromioclavicular joint injuries in a general population. METHODS: All acute shoulder injuries admitted to an orthopaedic emergency department were registered prospectively, using electronic patient records and a patient-reported questionnaire. The regional area was the city of Oslo with 632,990 inhabitants. Patients with symptoms from the acromioclavicular joint without fracture were registered as a dislocation (type II-VI) if the radiologist described widening of the joint space or coracoclavicular distance on standard anteroposterior radiographs. Patients without such findings were diagnosed as sprains (type I). RESULTS: Acromioclavicular joint injuries constituted 11% of all shoulder injuries (287 of 2650). The incidence was 45 per 105 person-years (95% confidence interval [CI] 40-51). 196 (68%) were diagnosed as sprains and 91 (32%) as dislocations. Median age of all acromioclavicular joint injuries was 32 years (interquartile range 24-44), and 82% were men. Thirty percent of all acromioclavicular joint injuries were registered in men in their twenties. Sports injuries accounted for 53%, compared to 27% in other shoulder injuries [OR 3.1 (95% CI 2.4-4.0; p < 0.001)]. The most common sports associated with acromioclavicular joint injuries were football (24%), cycling (16%), martial arts (11%), alpine skiing and snowboarding (both 9%), and ice hockey (6%). CONCLUSION: Our study suggests that in the general population, one in ten shoulder injuries involves the acromioclavicular joint and young men in sports are at highest risk. A prognostic level II cohort study.

Lisfranc injuries: Incidence, mechanisms of injury and predictors of instability.

BACKGROUND: In Lisfranc injuries the stability of the tarsometatarsal joints guides the treatment of the injury. Determining the stability, especially in the subtle Lisfranc injuries, can be challenging. The purpose of this study was to identify incidence, mechanisms of injury and predictors for instability in Lisfranc injuries. METHODS: Eighty-four Lisfranc injuries presenting at Oslo University Hospital between September 2014 and August 2015 were included. The diagnosis was based on radiologically verified injuries to the tarsometatarsal joints. Associations between radiographic findings and stability were examined. RESULTS: The incidence of Lisfranc injuries was 14/100,000 person-years, and only 31% were high-energy injuries. The incidence of unstable injuries was 6/100,000 person-years, and these were more common in women than men (P = 0.016). Intraarticular fractures in the two lateral tarsometatarsal joints increased the risk of instability (P = 0.007). The height of the second tarsometatarsal joint was less in the unstable injuries than in the stable injuries (P = 0.036). CONCLUSION: The incidence of Lisfranc injuries in the present study is higher than previously published. The most common mechanism of injury is low-energy trauma. Intraarticular fractures in the two lateral tarsometatarsal joints, female gender and shorter second tarsometatarsal joint height increase the risk of an unstable injury. LEVEL OF EVIDENCE: Level III, cross-sectional study.

Immobilization in external rotation after primary shoulder dislocation did not reduce the risk of recurrence: a randomized controlled trial.

BACKGROUND: The treatment of primary traumatic anterior shoulder dislocation varies widely from no immobilization, to two or three weeks of immobilization in internal rotation with the arm in a sling, to treatment with a brace in external rotation. The aim of the present clinical trial was to compare immobilization in internal and external rotation after anterior shoulder dislocation. METHODS: One hundred and eighty-eight patients with a primary anterior traumatic dislocation of the shoulder were randomly assigned to treatment with immobilization in either internal rotation (ninety-five patients) or external rotation (ninety-three patients) for three weeks. The primary outcome measure was a recurrent dislocation within twenty-four months of follow-up. RESULTS: The follow-up rate after a minimum period of two years was 97.9% (ninety-three of ninety-five) in the internal rotation group and 97.8% (ninety-one of ninety-three) in the external rotation group. The compliance rate with the immobilization was 47.4% (forty-five of ninety-five) in the internal rotation group and 67.7% (sixty-three of ninety-three) in the external rotation group. The intention-to-treat analyses showed that the recurrence rate was 24.7% (twenty-three of ninety-three) in the internal rotation group and 30.8% (twenty-eight of ninety-one) in the external rotation group (p = 0.36). CONCLUSIONS: Immobilization in external rotation does not reduce the rate of recurrence for patients with first-time traumatic anterior shoulder dislocation.