Internal bracing (IB) is an augmentation method using high-strength nonabsorbable tape. However, there is no detailed information about the direction, location, or number of IBs required for scapholunate interosseous ligament (SLIL) injury repair. Thus, this study compared the biomechanical characteristics of short-transverse IB, long-oblique IB, and the combination of short-transverse and long-oblique (Combo) IB for SLIL injury in a biomechanical cadaveric model. We prepared nine fresh-frozen full upper extremity cadaveric specimens for this study. The scapholunate distance, scapholunate angle, and radioscaphoid angle were measured using the MicroScribe digitizing system with the SLIL intact, after scapholunate dissociation and the three different reconstructions. Three-dimensional digital records were obtained in six wrist positions in each experimental condition. Short-transverse IB had a similar effect compared with long-oblique IB in addressing the widening of the scapholunate distance. However, both were less effective than Combo IB. For scaphoid flexion deformity, short-transverse IB had minimal effect, while long-oblique IB had a similar effect compared to Combo IB. Combo IB was the most effective for improving distraction intensity and rotational strength. This study provides important information about the biomechanical characteristics of three different IB methods for SLIL injury and may be useful to clinicians in treating scapholunate dissociation.

Purpose: It is generally accepted that a radial head fracture (RHF) with more than three parts is not suitable for repair; therefore, most authors suggest straightforward radial head arthroplasty (RHA). With up to 20% risk for reoperation after RHA, improvement in reduction and fixation techniques may represent a valuable alternative before further extending the indications for arthroplasty. To determine the functional results and radiological failure rate after osteosynthesis of multi-fragmentary RHF with more than three articular fragments. We specifically determined (1) the one-year Broberg and Morrey functional elbow score, (2) duration of fracture healing, (3) complication rate, and (4) number of patients converted to RHA. Methods: This study is a retrospective single-center case series. All patients who underwent primary osteosynthesis for RHF between 2012 and 2019 were included. Nine patients with an average age of 52 years had an average clinical and/or radiological follow-up of 49 months. Results: The preoperative imaging identified nine fractures with four fragments. Three patients underwent osteosynthesis with plates and screws, whereas six patients underwent osteosynthesis with only screws. The mean Broberg and Morrey score was 95 points. Overall, eight of the nine patients had satisfactory results. All patients retained their radial heads and showed radiological fracture healing. Only two patients presented with low-grade complications requiring no further surgery. Conclusion: Our study showed that osteosynthesis of RHF with up to four fragments can achieve good functional results with a low complication rate and seems to be a valid alternative to RHA.

The anconeus nerve is the longest branch of the radial nerve and suitable as a donor for the neurotization of the axillary nerve. The aim of this study was to map its topographical course with reference to palpable, anatomical landmarks. The anconeus nerve was followed in 15 cadaveric specimens from its origin to its entry to the anconeus. It runs between the lateral and the medial head of the triceps before entering the medial head and running intramuscularly further distal. Exiting the muscle, it lies on the periosteum and the articular capsule of the elbow, before entering the anconeus muscle. Two types of anconeus nerve in relation to branches innervating triceps were found: nine nerves also innervated the lateral triceps head, while the other six only contributed two branches to its innervation. The course of the anconeus nerve is important for harvesting as a donor nerve and to protect the nerve in surgical elbow approaches.

Background Ulnar styloid fractures can be associated with clinically significant instability of the distal radioulnar joint (DRUJ). However, the exact fragment size that results in DRUJ instability is unknown. Purpose The objective of this study was to determine the critical size of an ulnar styloid fracture that would result in a significant increase in DRUJ translation and forearm rotation. Methods Eight cadaveric specimens were used to investigate the effects of three different ulnar styloid fracture sizes on DRUJ instability: tip fracture, base fracture, and a fracture including the fovea. Forearm rotation and dorsopalmar DRUJ translation were measured after each sequential increase in fracture size. Results Relative to the uninjured state, a significant increase in forearm rotation and dorsopalmar translation was found for all three fractures. However, the fovea fracture showed a statistically significant increase in forearm rotation compared with all other fracture types and a statistically significant increase in total dorsopalmar translation compared with the tip fracture. Conclusion In this study, ulnar styloid fractures involving the fovea resulted in significantly greater DRUJ instability comparted to tip and base fractures alone. This study provides important biomechanical data regarding the critical size of ulnar styloid fractures that result in DRUJ instability and may aid in the surgical decision-making algorithm in these patients.