Rockwood type III is the most common type of acromioclavicular joint dislocation: A prospective cohort study investigating the incidence and epidemiology of acute acromioclavicular joint dislocations in an urban population

Clavicle fractures do not increase the occurrence of later subacromial pain syndrome. A registry-based case-control study with 15-25 years of follow-up of 131.838 persons from the Danish National Patient Register

Background

A clavicle fracture often changes the mechanical axes of the shoulder girdle due to displacement and shortening, potentially leading to scapular protraction and decreased subacromial space. If protraction of the scapula is a major risk factor for developing subacromial pain syndrome (SAPS), a previous clavicle fracture could increase the risk of later SAPS. The purpose of this study was to investigate if a previous clavicle fracture correlates with a higher occurrence or earlier diagnosis of SAPS.

Methods

In this retrospective case-control study with data from the Danish National Patient Register, all persons aged 18-60 years, with any hospital contact due to a clavicle fracture (DS420) between January 1, 1996, and December 31, 2005, were identified as cases. For each case, five controls, matched on age and sex, were identified. Primary outcome was the first hospital contact with a SAPS diagnosis (DM751-755) registered more than 180 days following the fracture. Follow-up was until November 01, 2021.

Results

21.973 cases and 109.865 controls were included. The incidence of clavicle fractures was 76 fractures per 100.000 persons per year. Twenty-three percent were female. 1.640 (7.46%) cases and 8.072 (7.35%) controls received a SAPS diagnosis within the following 15-25 years, demonstrating no significant difference in the occurrence of SAPS (P = .56). The mean time from fracture to SAPS diagnosis was shorter for cases compared to controls (4040 vs. 4442 days, P < .001), and cases were slightly younger when receiving the diagnosis (51.3 vs. 53.6 years, P < .001). 1614 cases underwent surgical fixation. This subgroup had a statistically significant higher occurrence of later SAPS diagnosis (205 cases, 13%, P < .001).

Conclusions

Persons with a previous clavicle fracture did not have an increased occurrence of receiving a SAPS diagnosis compared to matched controls. However, the diagnosis was given 1-2 years earlier for people with a previous fracture. Based on these findings, no strong argument for protraction of the scapula as a major risk factor for the development of SAPS was found.

A Self-Designed Endobutton Installation Device for Coracoclavicular Stabilization in Acute Rockwood Type III Acromioclavicular Joint Dislocation

OBJECTIVE

Endobutton technique could provide flexible coracoclavicular (CC) stabilization for acromioclavicular joint (ACJ) dislocation and achieved good clinical outcomes. However, the difficult part of this technique was placement of the Endobutton to the coracoid base. In this study, we designed an Endobutton installation device to place the Endobutton at the coracoid base. And we examined the clinical and radiographic outcomes of patients with acute Rockwood type III ACJ dislocation repaired with Endobutton using this device.

METHODS

We designed an Endobutton installation device to place the Endobutton at the coracoid base to achieve CC stabilization. We retrospectively reviewed 42 patients with acute Rockwood type III ACJ dislocation who underwent CC stabilization with Endobuttons placed either using this novel device (group I, n = 19) or the traditional technique (CC stabilization without using special device, group II, n = 23) from January 2015 to April 2020. The two groups were compared regarding the operative time, intraoperative blood loss, and clinical and radiologic outcomes at final follow-up. The operation-related complications were also evaluated. The Student's t test and the Mann-Whitney U-test were used to compare differences in continuous variables. Differences in categorical variables were assessed with either the Pearson's chi-squared test or Fisher's exact test.

RESULTS

Forty-two patients were clinically followed up for a minimum of 12 months. Compared with group II, group I had a significantly shorter mean operative time (56.05 ± 7.82 min vs. 65.87 ± 7.43 min, p < 0.01) and significantly lesser mean intraoperative blood loss (67.89 ± 14.75 mL vs. 94.78 ± 25.01 mL, p < 0.01). At final follow-up, there were no significant differences between the two groups in the visual analog scale score for pain, Oxford Shoulder Score, Disabilities of the Arm, Shoulder, and Hand score, and postoperative CC distance of the affected side. Loss of reduction occurred in four patients in group I and three patients in group II (p = 0.68); there were no other operation-related complications in either group.

CONCLUSIONS

The Endobutton installation device makes placement of the Endobutton at the coracoid base easier and achieves satisfactory clinical and radiologic outcomes without additional complications in acute Rockwood type III ACJ dislocation.

Acromioclavicular joint dislocation Rockwood type III and V show no difference in functional outcome and 91% recovered well without the need for surgery

PURPOSE

Acromioclavicular (AC) joint dislocations are common injuries, but the indication for and timing of surgery is debated. The objective of the study was to evaluate the results after acute AC joint dislocations Rockwood type III and V treated nonsurgically with the option of delayed surgical intervention.

METHODS

This is a prospective cohort study with clinical, radiological and patient-reported outcome assessment at baseline, 6 weeks, 3 months, 6 months and 1 year after acute AC joint dislocation. Patients aged 18-60 with acute AC joint dislocation and a baseline panorama (Zanca) radiograph with an increase in the coracoclavicular distance of >25% compared to the uninjured side were eligible for inclusion. All patients were treated nonsurgically with 3 months of home-based training and with the option of delayed surgical intervention. The primary outcome was the Western Ontario Shoulder Instability Index (WOSI). Secondary outcomes were surgery yes/no and the Shoulder Pain and Disability Index (SPADI).

RESULTS

Ninety-five patients were included. Fifty-seven patients were Rockwood type III and 38 patients were type V. There were no statistically significant differences in WOSI and SPADI between patients with type III and V injuries at any time point. Nine patients (9.5%) were referred for surgery; seven type III and two type V (ns).

CONCLUSION

Ninety-one percent of patients with acute AC joint dislocation Rockwood type III and V recovered without surgery and there were no differences in outcome scores between type III and V at any time point.

LEVEL OF EVIDENCE

Level IV.