John M. Itamura

Management of Chronic Deep Infection Following Rotator Cuff Repair

Background: Deep infection of the shoulder following rotator cuff repair is uncommon. There are few reports in the literature regarding the management of such infections. Methods: We retrospectively reviewed the charts of thirteen patients and recorded the demographic data, clinical and laboratory findings, risk factors, bacteriological findings, and results of surgical management. Results: The average age of the patients was 63.7 years. The interval between the rotator cuff repair and the referral because of infection averaged 9.7 months. An average of 2.4 procedures were performed prior to referral because of infection, and an average of 2.1 procedures were performed at our institution. All patients had pain on presentation, and most had a restricted range of motion. Most patients were afebrile and did not have an elevated white blood-cell count but did have an elevated erythrocyte sedimentation rate. The most common organisms were Staphylococcus epidermidis, Staphylococcus aureus, and Propionibacterium species. At an average of 3.1 years, all patients were free of infection. Using the Simple Shoulder Test, eight patients stated that the shoulder was comfortable with the arm at rest by the side, they could sleep comfortably, and they were able to perform activities below shoulder level. However, most patients had poor overhead function. Conclusions: Extensive soft-tissue loss or destruction is associated with a worse prognosis. Extensive débridement, often combined with a muscle transfer, and administration of the appropriate antibiotics controlled the infection, although most patients were left with a substantial deficit in overhead function of the shoulder.

Neer Award 2006: Biomechanical assessment of inferior tuberosity placement during hemiarthroplasty for four-part proximal humeral fractures.

Tuberosity malpositioning commonly occurs and is associated with a decline in clinical function after prosthetic shoulder reconstruction for proximal humeral fractures. This study assesses the biomechanical effects of inferior tuberosity position on glenohumeral joint forces and humeral head position at multiple positions. Eight fresh-frozen cadaveric shoulders were tested. Hemiarthroplasty was performed with preservation of anatomic tuberosity height and with 10 mm and 20 mm of inferior tuberosity displacement. The rotator cuff, deltoid, pectoralis major, and latissimus dorsi muscles were statically loaded. Contact forces and humeral head position were recorded within a functional range of motion. Glenohumeral joint forces shifted significantly superiorly (P < .05) at 30 degrees of abduction after both 10 mm and 20 mm of tuberosity displacement. At 60 degrees of glenohumeral abduction, glenohumeral joint forces remained significantly altered after tuberosity displacement of 10 mm and 20 mm compared with the intact height (P < .005). This study demonstrates that, during hemiarthroplasty performed for proximal humeral fractures, malpositioning the tuberosities inferiorly results in significant superior glenohumeral joint force displacement. These findings suggest that the mechanical advantage of the shoulder abductor muscles is compromised with inferior tuberosity malpositioning and may help to explain inferior functional results seen in these patients.

Human cadaveric study of subscapularis muscle innervation and guidelines to prevent denervation

The upper and lower subscapular nerves provide innervation to the subscapularis muscle. However, the axillary nerve may provide a significant innervation to the lower portion of the muscle. The prevalence and patterns of anomalous innervation of the subscapularis muscle were studied to determine if these variations increased the risk of muscle denervation during open shoulder surgery. Twenty human cadaveric shoulders were dissected, and the innervation to the subscapularis was defined. The distance from the nerve insertion to the shoulder joint was measured in neutral and maximal external rotation. In the most common variation, the lower subscapular nerve arose from the axillary nerve (5 specimens; 25%). Although external rotation of the shoulder brought the nerve insertion significantly more lateral (35.2 to 16.9 mm, P < .001), the origin of the nerve had no significant effect on nerve proximity to the joint. The closeness of the nerve insertions to the shoulder joint warrants care during an anterior approach to the shoulder and dissections on the anterior surface of the muscle. Subscapularis nerve damage or denervation may cause unexplained joint instability and subscapularis dysfunction.

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.

Serum interleukin-6 as a marker of periprosthetic shoulder infection.

BACKGROUND Infection after shoulder arthroplasty can be a devastating complication, and subacute and chronic low-grade infections have proven difficult to diagnose. Serum marker analyses commonly used to diagnose periprosthetic infection are often inconclusive. The purpose of this study was to evaluate the effectiveness of serum interleukin-6 (IL-6) as a marker of periprosthetic shoulder infection. METHODS A prospective cohort study of thirty-four patients who had previously undergone shoulder arthroplasty and required revision surgery was conducted. The serum levels of IL-6 and C-reactive protein (CRP), the erythrocyte sedimentation rate (ESR), and the white blood-cell count (WBC) were measured. The definitive diagnosis of an infection was determined by growth of bacteria on culture of intraoperative specimens. Two-sample Wilcoxon rank-sum (Mann-Whitney) tests were used to determine the presence of a significant difference in the ESR and WBC between patients with and those without infection, while the Fisher exact test was used to assess differences in IL-6 and CRP levels between those groups. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of each marker were also calculated. RESULTS There was no significant difference in the IL-6 level, WBC, ESR, or CRP level between patients with and those without infection. With a normal serum IL-6 level defined as <10 pg/mL, this test had a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 0.14, 0.95, 0.67, 0.61, and 0.62, respectively. CONCLUSIONS IL-6 analysis may have utility as a confirmatory test but is not an effective screening tool for periprosthetic shoulder infection. This finding is in contrast to the observation, in previous studies, that IL-6 is more sensitive than traditional serum markers for periprosthetic infection.

Treatment of soft tissue problems about the elbow.

The treatment of soft tissue problems about the elbow should be directed toward early coverage and functional rehabilitation. The current study reviews some of the available treatment options, with emphasis on the treatment of large soft tissue defects. The role of prophylactic soft tissue coverage also is discussed. For large defects not extending more than 8 cm below the elbow and for prophylactic soft tissue coverage, the authors recommend the pedicled latissimus flap, which provides reliable coverage and a generous blood supply that promotes healing at the site of injury.

Hemiarthroplasty for the treatment of distal humerus fractures: short-term clinical results.

Total elbow arthroplasty is the current gold standard of treatment for unreconstructable distal humerus fractures; however, longevity of the implant remains a concern in younger, more active patients. Distal humerus hemiarthroplasty offers an alternative and may allow for more durable results. The authors retrospectively evaluated the short-term clinical outcomes of 10 patients who underwent elbow hemiarthroplasty for distal humerus fractures. This short-term review suggests that distal humerus hemiarthroplasty may be an effective treatment for certain distal humerus fractures. Additional studies must be conducted to further define the role of elbow hemiarthroplasty for the treatment of complex fractures of the distal humerus.

The Influence of the Acromioclavicular Joint Degeneration on Supraspinatus Outlet Impingement and the Acromion Shape

Purpose. To assess the anatomic association of acromioclavicular joint degeneration to supraspinatus outlet impingement and the acromion shape. Methods. Sagittal oblique magnetic resonance images of 49 shoulders in 49 patients were reviewed. 29 of them (mean age, 59 years) underwent surgery for impingement with or without rotator cuff tear (group 1), whereas the 20 controls (mean age, 27 years) were treated for shoulder instability without rotator cuff disease or acromioclavicular joint derangement (group 2). The supraspinatus outlet and the acromion shape of the 2 groups were compared. Results. The difference in the mean supraspinatus outlet between groups 1 and 2 was 11% (514 vs 577 mm2, p=0.095) and between the subgroup (of group 1) with full thickness rotator cuff tears and group 2 was 17% (481 vs 577 mm2, p=0.036). Six of the acromions in group 1 were type III (hooked) compared to none in group 2. Conclusion. In severe acromioclavicular degeneration, distal clavicular excision is recommended, even in cases with an asymptomatic acromioclavicular joint, so as to prevent further osteophyte formation.

Luggage tag technique of anatomic fixation of displaced acromioclavicular joint separations.

Acromioclavicular joint dislocations are common injuries in active individuals. Most of these injuries may be treated nonoperatively. However, many techniques have been described when surgical management is warranted. A recent biomechanical study favors anatomic reconstruction of the conoid and trapezoid ligaments and the acromioclavicular joint capsule, as opposed to the traditional technique of excision of the lateral end of clavicle and transfer of the coracoacromial ligament to the intramedullary canal of the distal clavicle. We present a modification of the anatomic fixation technique using a luggage tag method, which places a graft under the base of the coracoid. This procedure has been associated with few redisplacements of the distal clavicle, reliable pain relief, and minimal postoperative morbidity. We found the luggage tag technique provides anatomic fixation of the distal clavicle and restoration of coronal and sagittal plane stability to the injured acromioclavicular joint. This procedure should reduce the possibility of coracoid fracture and decreases the risk of hardware complications associated with reconstruction techniques that violate the base of the coracoid process.Level of Evidence: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Computed tomography study of radial head morphology

Computed tomography scans of 22 cadaveric adult elbows were obtained in 3 forearm positions: full supination, neutral, and full pronation. The radial head dimensions, the radiocapitellar joints, and the proximal radioulnar joints were measured. Multivariate analysis of variance was used to determine which portions of each articulation were the most congruent. The results showed that the radial head tended to become uncovered at the radial lip (P < .001). The radiocapitellar joint was tighter in pronation than in supination (P = .001). The proximal radioulnar joint was most congruent at the middle proximal radioulnar joint, at the midportion and posterior aspects rather than the anterior aspect (P < .001). The proximal radioulnar joint coverage was between 69 degrees and 79 degrees . Prosthesis trial sizing should be judged by the articulations providing the most congruency: (1) the ulnar lip or trough of the radiocapitellar joint in pronation and (2) the posterior or midportion of the middle proximal radioulnar joint.