Topographical measurement of the attachments of the central band of the interosseous membrane on interosseous crests of the radius and ulna

Background: To suggest a reasonable isometric point based on the anatomical consistency of interosseous membrane (IOM) attachment in association with topographic characteristics of the interosseous crest, the footprints of the central band (CB) of the IOM on the radial and ulnar interosseous crests (RIC and UIC) were measured.Methods: We measured the distance from the CB footprints from each apex of both interosseous crests in 14 cadavers and the angles between the forearm axis of rotation (AOR) and the distal slopes of the RIC and UIC in 33 volunteers. Results: The CB footprints lay on the downslope of both interosseous crests with its upper margin on average 3-mm proximal from the RIC's apex consistently in the radial length, showing normality (p>0.05), and on average 16-mm distal from the UIC's apex on the ulna without satisfying normality (p<0.05). The average angle between the UIC's distal slope and the AOR was 1.3°, and the RIC's distal slope to the AOR was 14.0°, satisfying the normality tests (p>0.05), and there was no side-to-side difference in both forearms (p<0.05).Conclusions: The CB attached to the downslope just distal to the RIC's apex constrains the radius to the UIC that coincides with the AOR of the forearm circumduction, maintaining itself both isometrically and isotonically.

CT scan of the placement of the femoral tunnel in combined anterior cruciate ligament and anterior lateral ligament reconstruction by a single femoral tunnel using the outside-in technique

Background: The main difficulty with this ALL reconstruction method is the placement of the femoral tunnel as isometrically as possible. The femoral insertion of the ALL is usually located one centimeter posteriorly and proximal to the lateral epicondyle, at the level of the Lemaire vessels. The purpose of our study was to evaluate the placement of the femoral tunnel in ligament reconstruction by combined ACL and ALL reconstruction with a single femoral tunnel using the outside-in technique. Our hypothesis was that a single femoral tunnel by outside-in technique would allow satisfactory placement of the femoral insertion of the ALL.. Methods: We conducted a retrospective bi-centric study of all patients who underwent combined ACL and ALL reconstruction surgery with a common outside-in femoral technique. A postoperative low-dose knee CT scan with multiplane reconstructions was performed after patient consent. After locating the top of the epicondyle on three-dimensional CT scan reconstructions, the distances between the top of the lateral epicondyle and the center of the femoral tunnel in the frontal and sagittal planes were measured. These measurements were taken by a surgeon and a radiologist. Results: 45 patients were included and the average age was 29 years (17-39). 30 patients had a CT scan. Analysis of the placement of the femoral tunnel showed that 10 tunnels were placed posteriorly and proximal to the top of the lateral epicondyle. Conclusion: This study did not confirm our hypothesis. Combined ACL and ALL reconstruction by a single tunnel did not provide access to the isometric point of the femoral insertion of the ALL in a reproducible manner, despite open intra-operative identification of this point. This study highlights the difficulty of locating the femoral isometric point with a standard outside-in femoral guide. Developing a specific femoral guide might be useful.

Two-Staged Reconstruction for Symptomatic Humeral Medial Epicondyle Nonunion in Children: A Case Report

Few cases of humeral medial epicondyle nonunion develop to symptomatic condition. We report a pediatric case of distally displaced nonunion. At first, the palliative repair surgery was chosen due to irreduciblity of the epicondyle fragment at 10 years old. After 2 years and 3 months wait for maturation of ossification at the trochlea, the definitive surgery consisting of epicondylectomy and ligament reconstruction was performed. This is the first pediatric case of humeral medial epicondyle nonunion with an unossified trochlea which needed a two-staged surgery. We highlight the surgical plan aimed at anatomical ligament reconstruction focusing an isometric point of MCL.

The Optimal Suture Placement and Bone Tunnels for TFCC Repair: A Cadaveric Study

Background Transosseous repair of foveal detachment of the triangular fibrocartilage complex (TFCC) is effective for distal radioulnar joint stabilization. However, studies of the optimal foveal and TFCC suture positions are scant. Purpose The purpose of this study was to clarify the optimal TFCC suture position and bone tunnels for transosseous foveal repair. Materials and Methods Seven cadavers were utilized. The TFCC was incised at the foveal insertion and sutured at six locations (TFCCs 1–6) using inelastic sutures. Six osseous tunnels were created in the fovea (foveae 1–6). Fovea 2 is located at the center of the circle formed by the ulnar head overlooking the distal end of the ulna (theoretical center of rotation); fovea 5 is located 2 mm ulnar to fovea 2. TFCC 5 is at the ulnar apex of the TFCC disc; TFCC 4 is 2 mm dorsal to TFCC 5. TFCC 1 to 6 sutures were then placed through each of the six osseous tunnels, resulting in 36 combinations, which were individually tested. The forearm was placed in five positions between supination and pronation, and the degree of suture displacement was measured. The position with the least displacement indicated the isometric point of the TFCC and fovea. Results The mean distance of suture displacement was 2.4 ± 1.6 mm. Fovea 2, combined with any TFCC location, (0.7 ± 0.6 mm) and fovea group 5, combined with TFCC 4 location (0.8 ± 0.8) or with TFCC 5 location (0.9 ± 0.6) had statistically shorter suture displacements than any other fovea groups. Conclusion For TFCC transosseous repair, osseous tunnel position was more important than TFCC suture location.