Jin-Woo Kang

Where Is the Ulnar Styloid Process? Identification of the Absolute Location of the Ulnar Styloid Process Based on CT and Verification of Neutral Forearm Rotation on Lateral Radiographs of the Wrist

Background The location of the ulnar styloid process can be confusing because the radius and the hand rotate around the ulna. The purpose of this study was to identify the absolute location of the ulnar styloid process, which is independent of forearm pronation or supination, to use it as a reference for neutral forearm rotation on lateral radiographs of the wrist. Methods Computed tomography (CT) images of 23 forearms taken with elbow flexion of 70° to 90° were analyzed. The axial CT images were reconstructed to be perpendicular to the distal ulnar shaft. The absolute location of the ulnar styloid process in this study was defined as the position of the ulnar styloid process on the axial plane of the ulnar head relative to the long axis of the humeral shaft with the elbow set in the position for standard lateral radiographs of the wrist. To identify in which direction the ulnar styloid is located on the axial plane of the ulnar head, the angle between “the line of humeral long axis projected on the axial plane of the ulna” and “the line passing the center of the ulnar head and the center of the ulnar styloid” was measured (ulnar styloid direction angle). To identify how volarly or dorsally the ulnar styloid should appear on the true lateral view of the wrist, the ratio of “the volar-dorsal diameter of the ulnar head” and “the distance between the volar-most aspect of the ulnar head and the center of the ulnar styloid” was calculated (ulnar styloid location ratio). Results The mean ulnar styloid direction angle was 12° dorsally. The mean ulnar styloid location ratio was 1:0.55. Conclusions The ulnar styloid is located at nearly the ulnar-most (the opposite side of the humerus with the elbow flexed) and slightly dorsal aspects of the ulnar head on the axial plane. It should appear almost midway (55% dorsally) from the ulnar head on the standard lateral view of the wrist in neutral forearm rotation. These location references could help clinicians determine whether the forearm is in neutral or rotated position on an axial CT/magnetic resonance imaging scan or a lateral radiograph of the wrist.

Feasibility and Advantages of Full Thickness Skin Graft from the Anterolateral Thigh

BACKGROUND Full thickness skin graft (FTSG) gives better outcomes than split thickness skin graft (STSG), but it has the drawback of limited donor sites. Anterolateral thigh (ALT), a popular donor site of STSG, is also a popular donor site of perforator flaps. This area has the advantage of large flap size available with primary closure. Based on this we harvested FTSG instead of STSG from the ALT. METHODS We retrospectively reviewed 10 cases of FTSG from the ALT, with the recipient site of foot in 3, ankle in 2, lower leg in 2, forearm in 2, and wrist in 1 patient. In all cases elliptical full thickness skin was harvested from the ALT, and the donor site was closed primarily. The skin was defatted and placed onto the defect with vacuum-assisted closure (VAC). The skin size ranged 7-30 cm in length and 3-12 cm in width. Mean follow up period was 7 months (range, 3-13). RESULTS FTSG from the ALT provided durable wound coverage, with excellent color and texture matching. Partial (< 20%) graft failure was observed in 1 case, but no additional surgery was necessary. No patient reported donor site pain at postoperative 2 weeks. No donor site complications were encountered. No patient complained a feeling of tension in the thigh at final follow-up. CONCLUSIONS FTSG from the ALT is feasible with the aid of VAC. Considering the skin quality, large skin size available, early pain relief, and little donor site morbidity, the ALT should be revisited as a donor site of FTSG.

Accuracy of Radiographic Evaluation of Ulnar Styloid Base Fracture by Simple Radiogram

Purpose: There remains uncertain whether to fix an ulnar styloid fracture accompanied by distal radius fracture. Fixation should be required in cases of the fracture involving a fovea of ulnar head, an attachment site of deep portion of triangular fibrocartilage. We analyzed the patients with ulnar styloid fracture accompanied by distal radius fracture using simple radiograph and 3D computed tomography (3D CT) scan images, respectively, and compared accuracy of evaluation for the types of ulnar styloid fractures, which might designate the treatment methods. Materials and Methods: We retrospectively reviewed 168 patients who underwent surgery for distal radius fracture in our hospital from January 2005 to March 2015, and evaluated whether ulnar styloid base was involved using simple radiographs and 3D CT scan images. The accuracy of evaluation by simple radiographs was compared with the findings of 3D CT scan images. To avoid the effect of memory, evaluation using 3D CT scan images was performed in a randomized order 2 weeks after initial evaluation for simple radiograph. Results: On simple radiographs, 64 patients (38%) had ulnar styloid base fractures; however, 21 cases of these revealed nonbase fractures by 3D CT scan images. And 7 out of 104 cases, on simple radiographs, determined as nonbase fracture by simple radiographs, were diagnosed as base fractures by 3D CT scans. Based on the findings of 3D CT scan images, the accuracy of simple radiographic evaluation for types of ulnar styloid fractures was 83%, with 86% sensitivity and 82% specificity. The positive predictive value was 67% and the negative predictive value was 93%. Conclusion: Accuracy of radiographic evaluation of ulnar styloid base fracture accompanied by distal radius fracture, when compared with 3D CT, was 83%. Therefore, we recommend that 3D CT scan image–based evaluation should be performed in case of unclear involvement sites so as to determine whether to fix it or not.

Clinical Outcomes of Volar Oblique Ligament Reconstruction in Thumb Basal Joint Arthritis: Is It Still Useful for Eaton-Littler Stage III Osteoarthritis?

Introduction: Volar oblique ligament (VOL) is known as a primary trapeziometacarpal joint stabilizer. Because ligament laxity is one of most important cause of thumb basal joint arthritis, Eaton and Littler introduced their technique reconstructing VOL as a treatment of that; however, they recommended using this treatment only for Eaton-Littler stages I and II through their study result. We evaluated clinical outcomes of VOL reconstruction applied for patients with stage I, stage II, and even early stage III thumb basal joint arthritis. Material and Methods: We analyzed 21 patients who had undergone surgery for thumb basal joint arthritis in our hospital from May 2011 to October 2014 and had a minimum 12 month follow-up. All patients were women and the mean age at diagnosis was 58.5 years (range, 43-78 years). Six patients were Eaton stage I, 9 were II, and 6 were III. Functional outcome were evaluated using New York Orthopedic Hospital Wrist Scoring Scale, which assessed range of motion (ROM), grip power, radiologic findings, pain, and hand function. The stability of basal joint and progression of arthritis were also evaluated. Wilcoxon rank sum test was used for statistical analysis. The mean follow-up period was 21.6 months (12-56 months). Result: The overall functional results according to New York Orthopedic Hospital Wrist Scoring Scale were 1 excellent, 10 good, 7 fair, and 3 poor. We divided two groups (Eaton stage I, II vs III) and analyzed nonparametric test; however, it did not show a significant difference (P = .856). Two of 6 patients with stage III osteoarthritis showed poor result. At last follow-up, average grip power was 83.3% of normal side. The stability of VOL-reconstructed basal joint were restored and maintained in 15 of 21 joints. The arthritis was progressed in 4 joints, 1 of 6 Eaton stage I, 1 of 9 Eaton stage II, and 2 of 6 Eaton stage III joints. Conclusion: Our results suggested that VOL reconstruction is a reliable method for management of Eaton stage I and II osteoarthritis and can be applied even in early Eaton stage III osteoarthritis before performing salvage procedures.