Anatomic Variations of the Flexor Carpi Radialis Brevis: A Report of Five Cases.

The flexor carpi radialis brevis (FCRB) is a rare, anomalous musculotendinous structure of the wrist. Here, we report five cases of FCRB in a consecutive series of 123 distal radius fractures that were repaired by using volar locking plates.

Arthroscopic removal of an intra-articular osteoid osteoma of the radial styloid.

We describe a case of intra-articular osteoid osteoma arising in the radial styloid of a 21-year-old man. Plain radiographs were not diagnostic, but computed tomography, gadolinium-enhanced magnetic resonance imaging, and bone scintigraphy suggested the possibility of an osteoid osteoma. We arthroscopically removed the lesion; histological examination confirmed the diagnosis. The patient's symptoms disappeared immediately after surgery.

Interdigital amelanotic spindle-cell melanoma mimicking an inflammatory process due to dermatophytosis.

Herein, we report a rare case of amelanotic spindle-cell melanoma on the interdigit of the left fifth toe of an 83-year-old woman. She also had tinea pedis on the same part for more than 2 years, and the part in which the tumor developed had been macerated and colonized with both Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus. Histopathologically, the biopsy specimen was indistinguishable from that of nonspecific inflammatory granulation. Two biopsies could not lead us to the correct diagnosis until the totally excised specimen was evaluated with immunohistochemical analysis including S-100 and other melanocyte markers. The patient died with multiple metastases of the tumor 18 months after her first visit. This case suggests that refractory interdigital dermatophytoses should be treated by considering the possibility of concomitant malignant neoplasms, and immunohistochemical analysis is indispensable for differential diagnosis of malignant neoplasms suggesting nonspecific granulation.

Tensile properties of the human acetabular labrum-the first report.

The tensile properties of the human acetabular labrum were investigated using a uniaxial tension testing apparatus. The superior quadrant of the acetabular labrum was harvested from patients who underwent hip surgery. The obtained labra were sliced and shaped into rectangles for measuring uniaxial tension. We hypothesized that several characteristics such as gender, age, degeneration due to primary ailment, and the severity of the acetabular dysplasia would influence the tensile properties of the labrum. Antero-posterior radiographs of the pelvis have been used to evaluate the severity of the acetabular dysplasia and to diagnose the developmental dysplasia of the hip joint (DDH) clinically. Thus, we investigated the correlation between each of two representative radiological measurements-the CE angle and the Sharp angle-and tensile properties to assess the influence of the severity of the acetabular dysplasia. The tensile stress-strain curves for the labrum assumed a sigmoid shape. The mean tensile stress at failure for all specimens was 8.8+/-4.1 MPa. The mean strain at failure for all specimens was 48.5+/-10.4%. The mean tensile modulus was 66.4+/-42.2 MPa. Mean tensile stress at failure for specimens from males was greater than that of specimens from females. A significant difference was found in the maximum stress at failure among the three diagnosis-based groups: the other group withstood the highest stress before failure, whereas the osteoarthritis (OA) group withstood the lowest. No significant correlations with age or radiological characteristics were found for tensile stress, strain at failure, or tensile modulus. Our results suggest that labra obtained from male patients have stronger tensile stress than those from female patients, and that degenerative changes may influence the properties of the acetabular labrum.

Pelvic motion during total hip arthroplasty with translateral and posterolateral approaches.

We devised a special instrument to assess intraoperative pelvic motion and used this device to measure intraoperative pelvic motion in three dimensions. A total of 100 total hip arthroplasties (THAs) were performed using this device. Two approaches were utilized: 52 THAs were performed with the posterolateral approach and the remaining 48 with the translateral approach. The average angle of pelvic tilt in the THAs with the translateral approach was less than that with the posterolateral approach. The average internal rotation angle was 1.75 degrees with the translateral approach and 14.25 degrees with the posterolateral approach. With the posterolateral approach, the internal rotation of the pelvis frequently occurred during retraction of the femur using a Hohmann's retractor placed at the anterior rim of the acetablum, with flexion and internal rotation of the affected hip.

The effect of posterolateral reconstruction on range of motion and muscle strength in total hip arthroplasty.

Posterolateral reconstruction of the posterior capsule, piriformis tendon, and external rotators in total hip arthroplasty improves the stability of the hip joint. This study was performed to evaluate the effect of this reconstruction on range of motion (ROM) and circumferential muscle strength. We selected 58 limbs of 29 patients. Posterolateral reconstruction was performed in 13 patients (reconstruction group). Posterolateral reconstruction was not performed in 16 patients (nonreconstruction group). No significant differences were seen in preoperative and postoperative ROM between the 2 groups. The reconstruction group had significantly higher abduction muscle strength (P<.0001) and external rotation muscle strength (P<.01) than the nonreconstruction group. Posterolateral reconstruction may be effective in promoting the recovery of abduction and external rotator muscle strength, and it can improve joint stability without limiting ROM.

Scaphoid kinematic behavior after division of the transverse carpal ligament.

PURPOSE: The effect that carpal tunnel release (CTR) has on scaphoid motion has not been reported. Accordingly the purpose of this study was to determine the flexion/extension behavior of the scaphoid during global wrist radial/ulnar deviation before and after division of the transverse carpal ligament (TCL). METHOD: In this study we examined the in vitro kinematics of the scaphoid during wrist deviation in 6 cadaver forearms both before and after the division of the TCL using a computerized camera monitoring system. The specimens were evaluated in 13 different positions, from 20 degrees of radial deviation to 40 degrees of ulnar deviation at increments of 5 degrees. RESULTS: The data indicate that the difference in scaphoid position after TCL division is statistically significant when the wrist is in ulnar deviation of 15 degrees or greater. In addition a significant difference in scaphoid extension between pre- and post-TCL division conditions was found at 5 degrees of radial deviation as well as at 5 degrees or more of ulnar deviation and increased with increasing ulnar deviation. CONCLUSIONS: Scaphoid kinematics are altered considerably in radial-ulnar deviation after division of the TCL. This alteration may have long-term consequences and contribute to commonly seen post-CTR symptoms.