Chronic instability or degenerative arthritis of the sternoclavicular (SC) joint may occur after traumatic or spontaneous dislocation of the SC joint. Most commonly, chronic instability of the SC joint occurs anteriorly; however, posterior instability has an increased risk of serious complications because of proximity to mediastinal structures. Although chronic anterior instability of the SC joint does not resolve with nonsurgical treatment, patients often have mild symptoms that do not impair activities of daily living; however, chronic anterior SC joint instability may be functionally limiting in more active individuals. In these cases, surgical treatment with either (1) SC joint reconstruction or (2) medial clavicle resection, or both, can be done. Recurrent posterior instability of the SC joint also requires surgical treatment due to risk of injury to mediastinal structures. Recent literature describes various reconstruction techniques which generally show improved patient-reported outcomes and low complication rates.

Background: The lateral collateral ligament complex of the elbow is important in preventing posterolateral rotary instability of the elbow. Understanding the quantitative anatomy of this ligamentous complex and the overlying extensor musculature can aid in the surgical treatment of problems affecting the lateral side of the elbow. Purpose: To perform qualitative and quantitative anatomic evaluations of the lateral elbow ligamentous complex and common extensor muscle origins with specific attention to pertinent osseous landmarks. Study Design: Descriptive laboratory study. Methods: A total of 10 nonpaired, fresh-frozen human cadaveric elbows (mean age, 42.2 years; all male) were utilized. Quantitative analysis was performed using a 3-dimensional coordinate measuring device to quantify the location of pertinent bony landmarks, tendons, and ligament footprints of the lateral side of the elbow. Results: The extensor carpi radialis brevis was the only humeral footprint found to cross the radiocapitellar joint line, extending a mean 5.9 mm (95% CI, 4.7-7.0) distal to the joint line. With the elbow in full extension, the lateral ulnar collateral ligament (LUCL) humeral footprint was found 7.1 mm (95% CI, 4.7-9.4) anterior and 9.8 mm (95% CI, 8.4-11.2) distal to the lateral epicondyle and 8.6 mm (95% CI, 7.5-9.7) proximal to the radiocapitellar joint line, while the radial collateral ligament humeral footprint was found 6.6 mm (95% CI, 5.5-7.8) anterior and 5.6 mm (95% CI, 4.0-7.2) distal to the lateral epicondyle and 12.7 mm (95% CI, 11.4-14.0) proximal to the radiocapitellar joint line. The center of the ulnar attachment of the LUCL was found 1.4 mm (95% CI, 0.7-2.1) anterior and 2.4 mm (95% CI, 1.2-6.0) proximal to the supinator tubercle and 24.4 mm (95% CI, 22.7-26.1) distal to the radiocapitellar joint line. The center of the ulnar attachment of the annular ligament was found to be 17.3 mm proximal to the supinator tubercle. Conclusion: The current study provides measured distances of LUCL and radial collateral ligament attachments in reference to clinically relevant landmarks, which can potentially aid surgeons in performing more anatomic reconstruction or repair of the lateral ligamentous complex of the elbow.