A new circle method for measuring humeral torsion on MRI-scans less sensitive to Hill-Sachs lesions.

Objectives: The literature on humeral torsion angles (retrotorsion) reveals great inconsistencies between methodology and values. Decreased retrotorsion was suspected to correlate with instability, but evidence is contradictory. The measurement according to the gold standard method of Bernageau and Godefroy (B&G) can be challenging especially in the presence of Hill-Sachs-lesions. Therefore, we have developed and evaluated a new measurement method for the humeral torsion angle on MRI-scans. Materials and Methods: Three investigators have measured 67 patients (35 with shoulder instability, 32 healthy) on axial MRIs with 603 measurements used for reliability calculation. The new Circle-method determines the retrotorsion by overlaying two circles on the transversal section of the humeral head. The first circle is adjusted congruent with the margin of the humeral head, whereas the second circle is adjusted to the greater tubercle. The line bisecting the centres of these circles is defined as the humeral head axis. This method was compared to B&G. Results: The mean retrotorsion angle of all patients was 25°± 25° (mean ± SD) with B&G, and 24° ± 27° with the Circle-method. Neither method revealed a significant difference between stable and unstable shoulders (p = 0.47). Of the 35 patients with unstable shoulders 21 (60%) presented Hill-Sachs lesions. No significant differences between patients with or without Hill-Sachs lesions (Circle-method: p = 0.61; B&G: p = 0.67). The reliability parameters for both methods were similar. Conclusions: The new Circle-method is as precise as the method of B&G. It may yield more consistent values in cases with substantial Hill-Sachs-lesions. Our data do not suggest retrotorsion as a predictor of instability.

[Associated Injuries in Radial Head Fractures]. / Begleitverletzungen bei Radiuskopffrakturen.

Purpose Radial head fractures, particularly Mason I and II, are considered "harmless" injuries, and their severity is underestimated. In recent years, associated injuries to ligaments, cartilage, and adjacent bones have been studied in more detail. This meta-analysis collects the data on their incidence from the current literature. Methods A systematic review of the online databases PubMed, EMBASE, CINAHL and Cochrane Library was performed to identify clinical studies on associated injuries in radial head fracture. Their incidence was assessed as weighted means and broken down into Mason types. The clinical relevance of these injuries was not primarily assessed, but all available data were collected. Results Data on 1323 patients (48 % female) were extracted from 11 studies. 66 % had a Mason I, 21 % a Mason II, and 13 % a Mason III injury. In 33 % of all patients, associated injuries were found. The most common injury was damage to the lateral collateral ligaments (51 %), the second most common to the capitellum (22 %). 82 % of the Mason III fractures had associated injuries, compared to 36 % in Mason II, and 15 % in Mason I. Data on the clinical relevance of these injuries showed a rate of 11 % of persisting complaints requiring further treatment. Conclusions Associated injuries with radial head fractures are more frequent, and need treatment more frequently, than commonly assumed. Even in "harmless" Mason I fractures, severe associated injuries requiring surgical treatment are frequent. For clinical practice, persisting pain, even in a "simple" Mason I injury, should lead to a timely, specialised assessment and treatment.