Biomedical subjects

Ian K Lo

Publications and source records attributed to Ian K Lo.

4 recordsLinked to original sources

PubMed2006

The outcome of resection shoulder arthroplasty for recalcitrant shoulder infections.

Postarthroplasty infection is a devastating complication. In some patients, virulent pathogens or poor health complicate reconstruction. Resection arthroplasty is a viable option in such cases. Seven patients with resection arthroplasty following infection after shoulder arthroplasty were reviewed retrospectively at an average 20- month follow-up (range, 12-41). Average time between the initial procedure and the first debridement was 59.5 months (4-151 months). The average number of debridements was 2.2 per patient (range, 1-4 procedures). There were no complications, no recurrence of deep infection, no nerve damage, and no fractures. All patients were able to reach the opposite axilla, their backpocket and perineum, and their mouth. All but 1 patient were satisfied with their result. No patient had a satisfactory outcome via Neer's criteria. Resection arthroplasty is a reasonable salvage option for patients who are not good candidates for prosthetic reimplantation. This yields patients who can reliably perform basic activities of daily living.

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PubMed2004

Multidirectional instability: surgical decision making.

Although previous authors have described multidirectional instability of the shoulder, it was not until 1980 that Neer and associates solidified the current understanding and treatment of inferior and multidirectional instability. They emphasized the importance of differentiating this condition from the more common unidirectional instabilities and introduced the concept of an inferior capsular shift to globally tension the capsule anteriorly, inferiorly, and posteriorly, while thickening and reinforcing it on the side of greatest instability (i.e., anterior or posterior). Since the time of this initial description, the diagnosis and treatment of multidirectional instability has been fraught with difficulty and confusion. More recently, the advent of shoulder arthroscopy has blazed the trail for minimally invasive techniques to correct multidirectional instability, including arthroscopic thermal capsulorrhaphy and suture plication. However, despite strong opinions regarding these surgical techniques, when comparing open approaches to arthroscopic techniques for the treatment of multidirectional instability, long-term outcomes of arthroscopic techniques have yet to replicate those of open surgery.

Arthroscopy↗

PubMed2002

The use of the impingement test as a predictor of outcome following subacromial decompression for rotator cuff tendinosis.

PURPOSE: To evaluate the use of the impingement test as a predictor of outcome following subacromial decompression for patients with rotator cuff tendinosis. TYPE OF STUDY: Observational study. METHODS: An impingement test was administered to each patient immediately before surgery. Patients underwent a subacromial decompression and were assessed postoperatively at 3 and 6 months. The primary outcome measure was the Western Ontario Rotator Cuff Index (WORC). RESULTS: Thirty patients (mean age, 47.0 years; range, 29.4 to 71.2 years) took part in this study. There was no significant correlation between the classic impingement test (Neer's impingement sign before and after subacromial injection of local anesthetic) and the change in WORC score (r = -.174, P =.358). Similar results were obtained for the aggregate impingement test (pain at rest plus Neer's impingement sign plus Hawkins sign plus resisted abduction) before and after subacromial injection of local anesthetic (r = -.208, P =.270). When divided into categories of improvement following the classic impingement test (worse 0%-25%, 26%-50%, 51%-75%, 76%-100% better), there was no significant difference between groups for outcome as indicated by WORC score (P =.203). Results were similar for the aggregate impingement test (P =.271). CONCLUSIONS: The impingement test is a poor tool for predicting the success of subacromial decompression. There are 6 assumptions discussed that must hold true in order for the impingement test to be a useful predictor of outcome following subacromial decompression. If one or more of these assumptions are not met, or are only partially met, the impingement test would be rendered invalid as a predictor of outcome, as this study suggests.

Adult↗

PubMedDate not supplied

Cuff integrity after arthroscopic versus open rotator cuff repair: a prospective study.

Arthroscopic rotator cuff repair (RCR) has been reported to have good clinical results but high retear rates by ultrasound. We prospectively assessed postoperative cuff integrity and outcome after arthroscopic RCR (40 patients) and compared these results with open RCR (32 patients). Evaluation preoperatively and at 1 year included a physical examination and magnetic resonance imaging. American Shoulder and Elbow Surgeons and Constant scores improved significantly in both groups (P < .0001). Overall, 69% of repairs in the open group and 53% in the arthroscopic group were intact by magnetic resonance imaging. Of tears less than 3 cm in size, 74% in the open group and 84% in the arthroscopic group were intact. Of tears greater than 3 cm in size, 62% in the open group and 24% in the arthroscopic group were intact (P < .036). In the arthroscopic group, patients with an intact cuff had significantly greater strength of elevation (P = .01) and external rotation (P = .02). We conclude that open and arthroscopic RCRs have similar clinical outcomes. Cuff integrity is comparable for small tears, but large tears have twice the retear rate after arthroscopic repair.

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