Multiple Cultures and Extended Incubation for Upper Extremity Revision Arthroplasty Affect Clinical Care: A Cohort Study.

Skin flora organisms (SFOs) isolated from 1 to 2 tissue samples during shoulder and elbow revision arthroplasty are difficult to distinguish as contamination or infection. We examined the change in clinical care after implementation of an Arthroplasty Infection Protocol by increasing the number of intraoperative samples held for 10-day incubation to a minimum of 5. METHODS: Infection was defined as ≥3 cultures growing the same SFO or any one culture growing any other virulent organism. SFOs growing in 1 to 2 samples were defined as skin flora contaminant. All cases were compared with pre-Arthroplasty Infection Protocol institution standard to determine changes in microbiological diagnosis and resultant antibiotic treatment. RESULTS: Forty cases fulfilled the inclusion criteria: 50% of these were culture negative, and 35% grew Propionibacteria. When compared with the standard of obtaining one sample, this protocol altered the microbiological diagnosis and subsequent antibiotic treatment in 45% of cases (95% confidence interval 29% to 62%). This protocol had a predictive value of joint sterility in 95% of culture-negative cases (95% confidence interval 74% to 99%). DISCUSSION: The addition of 5 or more samples held for 10-day incubation reliably differentiated between joint infection, contamination, and sterility, which changed the course of care in 45% of surgical cases.

Management of glenohumeral arthritis in the young adult.

The majority of cases of glenohumeral arthritis in older adults are primary osteoarthritis and treatment algorithms are well defined, with shoulder arthroplasty providing reliable pain relief and functional improvement of satisfactorily duration. In younger adults, however, diagnoses are more complex and arthroplasty outcomes are less durable. Arthroscopy may be useful both as a diagnostic tool for characterizing lesions and as a therapeutic tool for debridement. Arthroscopic debridement is most likely to benefit patients with mild glenohumeral arthritis, small lesions, and involvement of only one side of the glenohumeral joint. Reconstruction of the humeral joint surface may consist of cartilage repair or reconstruction, resurfacing arthroplasty, or arthroplasty with a stemmed component. Patients treated with hemiarthroplasty avoid glenoid implant loosening, but the procedure provides less predictable pain relief than does total shoulder arthroplasty and may lead to increased postoperative glenoid erosion.

Contact pressure and glenohumeral translation following subacromial decompression: how much is enough?

Subacromial decompression is a common surgical procedure that has historically included coracoacromial ligament resection. However, recent reports have advocated preserving the coracoacromial ligament to avoid the potential complication of anterosuperior escape. The optimal subacromial decompression would achieve a smooth coracoacromial arch and decreased rotator cuff contact pressures while preserving the function of the arch in glenohumeral stability. We hypothesized that a subacromial decompression with a limited acromioplasty with preservation of the coracoacromial ligament can decrease extrinsic pressure on the rotator cuff similar to a coracoacromial ligament resection, without altering glenohumeral translation. Three different subacromial decompressions, including a "smooth and move," a limited acromioplasty with coracoacromial ligament preservation, and a coracoacromial ligament resection, were performed on 6 cadaveric specimens with intact rotator cuffs. Glenohumeral translation and peak rotator cuff pressure during abduction were recorded. No change in translation was observed after a smooth and move or a limited acromioplasty. Compared to baseline specimens, anterosuperior translation was increased at 30° of abduction following coracoacromial ligament resection (P<.05). Baseline rotator cuff pressure was greatest during abduction with the arm in 30° of internal rotation. Peak rotator cuff pressure decreased up to 32% following a smooth and move, up to 64% following a limited acromioplasty, and up to 72% following a coracoacromial ligament resection. Based on the present study, a limited acromioplasty with coracoacromial ligament preservation may best provide decompression of the rotator cuff while avoiding potential anterosuperior glenohumeral translation.

Shoulder arthroplasty in cases with avascular necrosis of the humeral head.

Avascular necrosis (AVN) is a relatively uncommon cause of glenohumeral arthritis. Previous retrospective reviews of shoulder arthroplasty for AVN have shown very good results in small numbers of patients. This study prospectively evaluated a consecutive series of 21 shoulders in 19 patients treated with the same modular prosthesis at a single institution. Of the shoulders, 8 developed AVN after a proximal humeral fracture, 1 was associated with a massive rotator cuff tear, 10 developed after corticosteroid therapy, and 2 were idiopathic. The patients, 14 women and 5 men, with a mean age of 54 years, were followed up for a mean of 4.7 years (range, 2 to 8 years). Hemiarthroplasty was performed in 15 shoulders, whereas 6 required total shoulder arthroplasty. Assessment included visual analog scales, the Simple Shoulder Test, and the American Shoulder and Elbow Surgeons Shoulder Score Index (SSI). Physical examination was performed, and radiographs were obtained. The visual analog scale scores for pain and function improved significantly after surgery (P < .01). The mean SSI score rose from 36 to 81 (where 0 indicates the worst outcome and 100 indicates the best outcome). The mean number of positive responses on the Simple Shoulder Test increased from 3 to 10. Mean active elevation increased from 88 degrees to 123 degrees . External rotation improved from 7 degrees to 34 degrees , and internal rotation improved from L4 to T12. No difference in outcome was noted based on age or sex. Patients with steroid-related or idiopathic AVN had greater pain and functional impairment preoperatively (mean SSI score, 26) than those with prior fracture or rotator cuff tear (mean SSI score, 49) (P < .01). Postoperatively, however, these groups fared equally well (mean SSI score, 78 vs 82). Shoulder arthroplasty for AVN produces good pain relief and function, although a concurrent series with osteoarthritis yielded better results. Forward elevation did not approach normal as had been previously reported.

A prospective functional outcome study of shoulder arthroplasty for osteoarthritis with an intact rotator cuff.

Prospective pain relief and functional outcome data were obtained on 65 shoulder arthroplasties in 55 patients. Thirty-seven total shoulder arthroplasties (TSAs) and twenty-eight hemiarthroplasties were followed up for a mean of 4.3 years (range, 2-8 years). The mean age was 63 years. Pain scores on a visual analog scale improved from a preoperative mean of 64 to 12 postoperatively. TSA and hemiarthroplasty postoperative scores did not differ significantly, but TSA patients started with a worse preoperative score and improved more. Five other visual analog scale scores improved, including function and quality of life. There were similar relationships between TSAs and hemiarthroplasties in each instance (poorer preoperative scores and more improvement). The American Shoulder and Elbow Surgeons Shoulder Score Index improved from 39 to 88 with surgery. The hemiarthroplasty group improved from a mean of 42 to 84, and the TSA group improved from 37 to 91. Although the numerical differences were small, the superiority of TSAs with regard to final score and rate of improvement was statistically significant. Patients with the poorest preoperative scores improved the most, regardless of prosthesis type. Mean active forward elevation improved from 100 degrees to 147 degrees, external rotation improved from a mean of 7 degrees to 39 degrees, and internal rotation improved by a mean of 3 spinal segments. These measures did not differ between TSA and hemiarthroplasty patients. One implant failure was treated with revision from TSA to hemiarthroplasty. Radiographic parameters characterizing component position and offset were measured, but none was found to predict outcome. The results suggest a modest superiority of TSA over hemiarthroplasty in the medium term. Because both TSA and hemiarthroplasty provide considerable and nearly comparable improvement, the long-term risks of glenoid wear and loosening need to be clearly defined before a definitive conclusion can be reached regarding the differential indications for these two procedures.