Management of chronic shoulder infections utilizing a fixed articulating antibiotic-loaded spacer.

BACKGROUND: Literature on management of chronic shoulder infections is limited. The purpose of this study was to examine the efficacy of a standardized protocol for the management of chronic shoulder infections, including periprosthetic infections, utilizing an articulating antibiotic-loaded spacer. MATERIAL AND METHODS: Thirty patients with chronic shoulder infections (4 primary and 26 postoperative) were treated with aggressive debridement, implantation of an antibiotic-loaded articulating spacer, and systemic antibiotics. Twenty-seven patients (90%) were compromised hosts. Eighteen patients (group I) elected to keep the spacer but three patients later underwent reimplantation, thus fifteen patients (group IA) were using the spacer as a prosthesis at their latest follow-up of 2.4 years. Twelve patients (group II, follow-up of 2.3 years) underwent reimplantation of a prosthesis. RESULTS: Eradication of infection was accomplished in all 30 patients. Group IA patients had a Disability of Arm Shoulder and Hand (DASH) score of 50, Simple Shoulder Test (SST) score of 5, forward flexion of 73 degrees, abduction of 71 degrees, and external rotation of 29 degrees. Group II patients had a DASH score of 58, SST score of 5, forward flexion of 78 degrees, abduction of 83 degrees, and external rotation of 19 degrees. The differences between these 2 groups were not significant. DISCUSSION: Chronic shoulder infections can be successfully treated with a protocol of aggressive debridement, antibiotic-loaded articulating spacer, and systemic antibiotics. Prolonged implantation of an articulating spacer may be a viable option in select low-demand patients with comorbidities.

Analysis of the capsule and ligament insertions about the acromioclavicular joint: a cadaveric study.

PURPOSE: The purpose of this study was to analyze the capsular and ligamentous insertions about the acromioclavicular (AC) joint to determine the amount of bone that can be removed without destabilizing the joint. METHODS: We dissected 28 cadaveric shoulders. The AC ligament insertions were measured under loupe magnification with a digital caliper on the acromial and clavicular sides on the anterior, posterior, superior, and inferior edges. We measured the distance to the coracoacromial (CA) and coracoclavicular ligaments. In addition, the axial and coronal angle of the AC joint was measured. RESULTS: The AC joint capsular insertion on the acromion begins, on average, 2.8 mm (range, 2.3 to 3.3 mm) from the medial acromion and begins on the lateral clavicle a mean of 3.5 mm (range, 2.9 to 3.9 mm) from the distal clavicle. The mean capsular width ranged from 1.6 to 2.9 mm. The mean distance from the medial acromion to the CA ligament insertion was 3.5 mm. The mean axial angle of the AC joint was 51 degrees , with a 12 degrees coronal angle. The mean distance from the lateral clavicle to the start of the trapezoid ligament was 14.7 mm, and that to the conoid ligament was 32.1 mm. CONCLUSIONS: An anatomic-based recommendation for safe AC joint resection is that 2 to 3 mm of the medial acromion and 3 to 4 mm of the distal clavicle can be resected without removing the AC capsular insertions. The trapezial and CA attachments are in close proximity to the AC capsular insertions. Medial resections greater that 15 mm will begin to take down the trapezoid ligament. Arthroscopic bone resection should be directed into the AC joint at approximately 50 degrees in the axial plane and 12 degrees in the coronal plane for safe symmetric resection. CLINICAL RELEVANCE: These anatomic measurements suggest that AC joint resections (5 to 7 mm) with 2 to 3 mm from the acromial side and 3 to 4 mm from the clavicular side will not disrupt the stabilizing ligaments of the AC joint after distal clavicle resection.