AIM To provide a "patient-normalized" parameter in the proximal forearm. METHODS Sixty-three cadaveric upper extremities from thirty-five cadavers were studied. A muscle splitting approach was utilized to lo...AIM To provide a "patient-normalized" parameter in the proximal forearm. METHODS Sixty-three cadaveric upper extremities from thirty-five cadavers were studied. A muscle splitting approach was utilized to locate the posterior interosseous nerve(PIN) at the point where it emerges from beneath the supinator. The supinator was carefully incised to expose the midpoint length of the nerve as it passes into the forearm while preserving the associated fascial connections, thereby preserving the relationship of the nerve with the muscle. We measured the transepicondylar distance(TED), PIN distance in the forearm's neutral rotation position, pronation position, supination position, and the nerve width. Two individuals performed measurements using a digital caliper with inter-observer and intraobserver blinding. The results were analyzed with the Wilcoxon-Mann-Whitney test for paired samples. RESULTS In pronation, the PIN was within two confidence intervals of 1.0 TED in 95% of cases(range 0.7-1.3 TED); in neutral, within two confidence intervals of 0.84 TED in 95% of cases(range 0.5-1.1 TED); in supination,within two confidence intervals of 0.72 TED in 95% of cases(range 0.5-0.9 TED). The mean PIN distance from the lateral epicondyle was 100% of TED in a pronated forearm, 84% in neutral, and 72% in supination. Predictive accuracy was highest in supination; in all cases the majority of specimens(90.47%-95.23%) are within 2 cm of the forearm position-specific percentage of TED. When comparing right to left sides for TEDs with the signed Wilcoxon-Mann-Whitney test for paired samples as well as a significance test(with normal distribution), the P-value was 0.0357(significance-0.05) indicating a significant difference between the two sides.CONCLUSION This "patient normalized" parameter localizes the PIN crossing a line drawn between the lateral epicondyle and the radial styloid. Accurate PIN localization will aid in diagnosis, injections, and surgical approaches.展开更多
Purpose: Failure after radial head arthroplasty is uncommon, but clinically significant. Treatment for failure may involve implant removal. We describe fourteen patients who underwent implant removal after failed radi...Purpose: Failure after radial head arthroplasty is uncommon, but clinically significant. Treatment for failure may involve implant removal. We describe fourteen patients who underwent implant removal after failed radial head arthroplasty. Methods: A retrospective review was performed to determine the cause of failure and clinical data were prospectively collected. Results: At mean follow up of 38 months the mean VAS for pain score was 3.0 and the mean DASH score was 40.5. The mean MEPS was 69. All patients demonstrated improved elbow range of motion. Mean elbow flexion at final follow up was 124°to an average extension deficit of 25°. Fifty percent of patients exhibited clinical symptoms of cubital tunnel syndrome. Three patients required additional surgery after implant removal. Conclusions: Implant removal for failed radial head arthroplasty improves range of motion and demonstrates acceptable outcomes at intermediate-term follow up. However, 50% of patients developed cubital tunnel syndrome and 21% required revision surgery.展开更多
文摘AIM To provide a "patient-normalized" parameter in the proximal forearm. METHODS Sixty-three cadaveric upper extremities from thirty-five cadavers were studied. A muscle splitting approach was utilized to locate the posterior interosseous nerve(PIN) at the point where it emerges from beneath the supinator. The supinator was carefully incised to expose the midpoint length of the nerve as it passes into the forearm while preserving the associated fascial connections, thereby preserving the relationship of the nerve with the muscle. We measured the transepicondylar distance(TED), PIN distance in the forearm's neutral rotation position, pronation position, supination position, and the nerve width. Two individuals performed measurements using a digital caliper with inter-observer and intraobserver blinding. The results were analyzed with the Wilcoxon-Mann-Whitney test for paired samples. RESULTS In pronation, the PIN was within two confidence intervals of 1.0 TED in 95% of cases(range 0.7-1.3 TED); in neutral, within two confidence intervals of 0.84 TED in 95% of cases(range 0.5-1.1 TED); in supination,within two confidence intervals of 0.72 TED in 95% of cases(range 0.5-0.9 TED). The mean PIN distance from the lateral epicondyle was 100% of TED in a pronated forearm, 84% in neutral, and 72% in supination. Predictive accuracy was highest in supination; in all cases the majority of specimens(90.47%-95.23%) are within 2 cm of the forearm position-specific percentage of TED. When comparing right to left sides for TEDs with the signed Wilcoxon-Mann-Whitney test for paired samples as well as a significance test(with normal distribution), the P-value was 0.0357(significance-0.05) indicating a significant difference between the two sides.CONCLUSION This "patient normalized" parameter localizes the PIN crossing a line drawn between the lateral epicondyle and the radial styloid. Accurate PIN localization will aid in diagnosis, injections, and surgical approaches.
文摘Purpose: Failure after radial head arthroplasty is uncommon, but clinically significant. Treatment for failure may involve implant removal. We describe fourteen patients who underwent implant removal after failed radial head arthroplasty. Methods: A retrospective review was performed to determine the cause of failure and clinical data were prospectively collected. Results: At mean follow up of 38 months the mean VAS for pain score was 3.0 and the mean DASH score was 40.5. The mean MEPS was 69. All patients demonstrated improved elbow range of motion. Mean elbow flexion at final follow up was 124°to an average extension deficit of 25°. Fifty percent of patients exhibited clinical symptoms of cubital tunnel syndrome. Three patients required additional surgery after implant removal. Conclusions: Implant removal for failed radial head arthroplasty improves range of motion and demonstrates acceptable outcomes at intermediate-term follow up. However, 50% of patients developed cubital tunnel syndrome and 21% required revision surgery.
