Search PubMed⌕ Search

PubMed · 7068720

Posterior acromioclavicular dislocation.

Abstract

Posterior dislocation of the acromioclavicular joint with the lateral end of the clavicle locked behind the acromion has only rarely been described. This paper present such a case diagnosed two weeks after the shoulder was injured in an accident. The clavicle was locked behind the articular surface of the acromion, restricting the movement of the shoulder and causing considerable pain. Anteroposterior radiographs showed a high-riding clavicle but no gap in the joint, but the axial view showed the dislocation. At operation the coracoclavicular ligaments were found overstretched but not ruptured. As reduction of the acromioclavicular joint was not possible, the lateral end of the clavicle was resected. Although the result was perfect, we consider the correct treatment should be early closed or open reduction of the acromioclavicular joint.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

P Søndergård-Petersen, P Mikkelsen. 1982. Posterior acromioclavicular dislocation.. https://doi.org/10.1302/0301-620x.64b1.7068720

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

High prevalence of symptomatic enthesopathy of the shoulder in ankylosing spondylitis: deltoid origin involvement constitutes a hallmark of disease.

OBJECTIVE: To examine the prevalence and characteristics of shoulder involvement in ankylosing spondylitis (AS). To analyze the sensitivity and specificity of shoulder lesions defined by magnetic resonance imaging (MRI) in patients with AS. METHODS: Prevalence of shoulder involvement was ascertained by chart review of 400 AS patients. One hundred of these patients and 285 controls were selected for clinical evaluation. AS patients with a clinically defined shoulder disorder (n = 15) and a control group of 91 patients (94 shoulders) with nonspecific shoulder pain were studied with MRI. Fifty-four MRI-defined variables per shoulder were analyzed by 2 observers. A third cohort of patients with AS (n = 76) was prospectively evaluated by clinical exam for AS-specific shoulder lesions identified on MRI. RESULTS: Shoulder pain was recorded in 3.5% of patients by chart review. Shoulder involvement by clinical evaluation was noted in 24.7% of patients versus 14.2% of controls (odds ratio [OR] 8.17, 95% confidence interval [95% CI] 3.14-21.28, P < 0.001). Rotator cuff tendinitis was significantly more prevalent in patients (15.1%) than controls (3.5%; OR 8.17, 95% CI 2.66-25.14, P < 0.001). Acromioclavicular joint arthrosis was the most common lesion observed in AS shoulders (94%), although specificity was low (32%). Bone marrow edema at any entheseal site was noted in significantly more AS shoulders (70.6%) than in control (19.1%) shoulders (P < 0.001, corrected P = 0.02). Erosion of the greater tuberosity with or without adjacent bone edema had the best combination of sensitivity (58-65%) and specificity (86-92%). Intense acromial entheseal edema at the deltoid origin was observed only in AS shoulders (41.2%; P < 0.001). Evaluation of a prospective cohort of patients with AS showed that 22.4% had rotator cuff enthesopathy. CONCLUSION: Shoulder lesions in AS are common and characterized clinically by rotator cuff tendinitis and on MRI by intense bone edema localized to the supraspinatus/greater tuberosity and deltoid/acromial entheses. Intense acromial bone edema at the deltoid origin is a hitherto undescribed and highly specific feature of AS. Enthesopathy of the rotator cuff is underrecognized in AS and should be incorporated into instruments measuring enthesitis.

Acromioclavicular Joint↗

Synovial chondromatosis of the acromioclavicular joint.

A 53-year-old woman presented with swelling of 3 years' duration on the right anterior chest wall. A radiograph showed coarse calcifications around the subclavicular region and erosion of the ipsilateral acromioclavicular joint. Computed tomography also showed calcifications in soft tissue. Magnetic resonance imaging revealed a tumor around the clavicle extending to the anterior aspect of chest wall, which had low signal intensity on T1-weighted imaging and high signal intensity on T2-weighted imaging. The histologic findings were of a hyaline cartilage-like mass consisting of mature chondrocytes and an extracellular matrix. The histologic diagnosis of synovial chondromatosis was made. The present case is unusual in respect of the location and size of the tumor.

Acromioclavicular Joint↗

Stability of acromioclavicular joint reconstruction: biomechanical testing of various surgical techniques in a cadaveric model.

BACKGROUND: Despite reports of excellent results with the Weaver-Dunn coracoacromial ligament transfer, many authors recommend augmenting the transfer with supplemental fixation. The authors of this study sought to determine whether there is a biomechanical basis for this assertion and which augmentative method, if any, most closely restored acromioclavicular motion to normal. HYPOTHESIS: Augmentative coracoclavicular fixation provides better restoration of normal acromioclavicular joint laxity and an increased failure load when compared with the Weaver-Dunn reconstruction alone. STUDY DESIGN: Controlled laboratory cadaveric study. METHODS: Native acromioclavicular joint motion was measured using an infrared optical measurement system. Acromioclavicular and coracoclavicular ligaments were then cut, and 1 of 6 reconstructions was performed: Weaver-Dunn, suture cerclage, and 4 different suture anchors. Acromioclavicular joint motion was reassessed, a cyclic loading test was performed, and the failure load was recorded. RESULTS: After Weaver-Dunn reconstruction, mean anteroposterior laxity increased from 8.8 +/- 2.9 mm in the native state to 41.9 +/- 7.6 mm (P < or = .01), and mean superior laxity increased from 3.1 +/- 1.5 mm to 13.6 +/- 4.4 mm (P < or = .01). Weaver-Dunn reconstructions failed at a lower load (177 +/- 9 N) than all other reconstructions (range, 278-369 N) (P < or = .05). Reconstruction using augmentative fixation allowed less acromioclavicular motion than Weaver-Dunn reconstruction (P < or = .05) but more motion than the native ligaments (P < or = .05). Specifically, mean superior laxity after reconstruction ranged between 6.5 and 9.0 mm compared with the native ligaments (3.1 +/- 1.5 mm) and the Weaver-Dunn reconstructions (13.6 +/- 4.4 mm). Mean anteroposterior laxity after the reconstructions tested ranged between 21.8 and 33.2 mm, compared with the native ligaments (8.8 +/- 2.9 mm) and the Weaver-Dunn reconstructions (41.9 +/- 7.6 mm). CONCLUSION: Although none of the augmentative methods tested restored acromioclavicular stability to normal, all proved superior to the Weaver-Dunn reconstruction alone. CLINICAL RELEVANCE: This study suggests that when performing acromioclavicular reconstruction, supplemental fixation should be used because it provides more stability and pull-out strength than the Weaver-Dunn reconstruction alone.

Acromioclavicular Joint↗