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The opposable thumb provides both stability and mobility and is needed to accomplish different prehensile tasks. The trapezium is a complex bone, with a distal articular surface that is convex in the sagittal plane of the thumb and concave in the coronal plane of the thumb. The numerous additional articulations with the carpus and the oblique orientation to the main plane of the hand makes it difficult to evaluate the trapeziometacarpal joint using standard hand or wrist radiographic views. This review gives an overview of the different radiological views that have been described for the thumb with an emphasis on their historical origin and positioning during radiography. We also describe different measurements and classifications that can be obtained using different thumb radiographs.

Background The effect of obliquity of tendon laceration on repair strength is not well studied. The overwhelming majority of biomechanical studies assess repair strength following a laceration that is perpendicular to the long axis of the tendon. The aim of this study was to investigate whether the angle of tendon laceration affects the core suture strength. Methods In all, 110 fresh human cadaveric flexor tendons were cut at varying angles of 15°, 30°, 45°, and 60° and the control group at 90°. All tendons were repaired with 6-strand modified Tang technique. The repair strength was tested using a custom-made tensioning machine, and the initial static gap force and the ultimate breaking force were measured. Results The mean gap force and 95% confidence interval (CI) for the 15°, 30°, 45°, 60°, and 90° groups were 15.2 N (11.4-19.0 N), 15.8 N (13.6-18.1 N), 15.6 N (13.1-18.4 N), 16.6 N (13.7-19.5 N), and 22.3 N (16.6-27.9 N), respectively. In the same respective order, the break force and 95% CI were 25.9 N (21.9-29.8 N), 26.5 N (23.2-29.7 N), 31.1 N (26.1-36.1 N), 35.6 N (28.2-43.1 N), and 51.8 N (62.5-41.0), respectively. The Fisher least significant difference demonstrated significant differences between the control group and all experimental groups for both gap force and break force. Conclusions Obliquity of tendon laceration affects the core suture strength when compared with a transverse cut. Flexor tendons cut at 90° demonstrated a higher overall gap force and breaking strength that were statistically significant when compared with all obliquely cut groups. These findings should be considered when repairing and starting postoperative therapy for obliquely cut tendons.

A 35 year-old right-handed female presented with persistent wrist pain lasting two years. Imaging disclosed an accessory tendon-shaped structure, identified as a Flexor Carpi Radialis Brevis, strangling the Flexor Carpi Radialis tendon at the wrist during effort. Surgical exploration found the insertion of the Flexor Carpi Radialis Brevis to be bifid. Resection of the stenosing branch and the fibrotic tendon sheath restored strength in the right wrist and painless symmetrical motion compared to the left wrist ten weeks postoperatively.

We assess the distribution of trapezial inclination in a young population in order to propose a threshold for trapezial dysplasia. One hundred peritrapezial views were reconstructed from wrist computed tomography scan datasets to measure trapezial inclination. Seventy peritrapezial views were constructed from 10 datasets to assess the influence of radiograph rotation. Mean trapezial inclination in our population was 8° (range 0.2–17.9). Fifteen degrees of radiographic pronation or supination did not alter trapezial inclination significantly. Intra-rater consistency and absolute agreement had an interclass correlation (ICC) of 0.95. Inter-rater consistency and absolute agreement had an ICC of 0.88. Trapezial inclination is a reliable measurement for trapezial dysplasia with an excellent intra-rater and good inter-rater reliability and does not change significantly with 15° of radiographic pronation or supination. These normal values can be used to propose a threshold for trapezial dysplasia in the management of trapeziometacarpal joint instability in the younger population. Level of evidence: IV

Background Although outcome of volar plating is generally good, care should be taken to avoid specific iatrogenic and preventable complications, with an incidence reporting averaging 15%. Flexor tendon rupture due to a prominent plate, extensor tendon rupture due to a dorsal protruding screw tips, cartilage lesions due to intra-articular screw placement, loss of reduction due to insufficient stability, and persisting ulnar pain with distal radioulnar joint instability due to unstable triangular fibrocartilaginous complex lesions or unstable ulnar styloid base fractures all have been described. Purpose We believe that a majority of these complications can be prevented by meticulous assessment of several intraoperative parameters during volar plating. Therefore, we introduce the WRIST protocol, a stepwise easy-to-remember manual that combines multiple fluoroscopic measurements to guide intraoperative decision making. Conclusion Large prospective studies of the “WRIST” protocol are needed for validation. But we believe that it may help surgeons to optimize surgical technique, functional and radiographic outcome, and prevent complications when treating distal radial fractures.