Setsuo Ninomiya

Endoscopic management of carpal tunnel syndrome.

This article describes a subcutaneous endoscopic operative procedure for carpal tunnel syndrome and analyzes its effectiveness using electrophysiological data. Subcutaneous transverse carpal ligament release under universal subcutaneous endoscope (USE) was performed using local anesthesia without pneumotourniquet in 54 hands of 45 patients since June 1986. The mean follow-up period was 13.8 months. Sensory disturbances began to subside immediately after the operation and disappeared within 2 months in all cases. After the disappearance of sensory disturbances, we performed postoperative electrophysiological studies in 27 patients (33 hands). Postoperative electrophysiological data were significantly improved in all cases. Patients did not suffer from any serious complications such as motor branch injuries of the median nerve, hypesthesia of the palm, or injuries of the superficial palmar arch. From these results, we conclude that the transverse carpal ligament can be safely incised by this procedure.

Dynamic external finger fixator for fracture dislocation of the proximal interphalangeal joint

The treatment of fracture dislocations of the proximal interphalangeal joint often results in pain and stiffness. A small dynamic external finger fixator was designed to maintain the reduced position of the dislocated middle phalanx and allow early active range-of-motion exercise. Four patients with acute unstable fracture dislocations and three with old malunited fracture dislocations of the proximal interphalangeal joint were treated with this apparatus. The average range of the proximal interphalangeal joint motion with this device was 88 degrees. The average follow-up period was 21 months.

Avascular necrosis of the femoral head. Natural history and magnetic resonance imaging

We studied the prognostic value of MRI in 32 radiographically normal, asymptomatic hips in 25 patients at risk of osteonecrosis from glucocorticoids or alcoholism. The early findings were band-like hypointense zones on spin-echo images. No operations were performed. Life-table survival curves showed that femoral heads in which the hypointense zone traversed the middle portion of the head were most at risk of subsequent segmental collapse.

Primary osteoarthritis of the hip joint in Japan.

Diagnostic criteria for primary osteoarthritis of the hip joint in the Japanese population were determined by the roentgenographic measurements of the center-edge (CE) angle, the Sharp angle, and the acetabular roof obliquity in 254 normal hips. Primary osteoarthritis must meet the following conditions: (1) absence of femoral head deformities; (2) a CE angle of Wiberg greater than 19 degrees; (3) a Sharp angle less than 45 degrees; and (4) acetabular roof obliquity less than 15 degrees. These measurements are taken from roentgenograms during the early stage of the disease. Under these criteria, primary osteoarthritis accounted for only 0.65% of 2000 consecutive cases of osteoarthritis. Observation of the natural course of primary osteoarthritis revealed two subtypes. The superolateral type developed from the subset of normal hips with a relatively greater degree of acetabular roof obliquity.

Evaluation of carpal canal pressure in carpal tunnel syndrome

Preoperative electrophysiologic testing and intraoperative carpal canal pressure measurements were performed on 957 hands in 647 patients with clinical signs of carpal tunnel syndrome. Fifty-five symptomatic hands in 48 patients were normal in both distal sensory latency and distal motor latency preoperatively. Carpal canal pressure was, however, significantly elevated compared to control data in all 55 hands. After complete subcutaneous release of the carpal canal using the Universal Subcutaneous Endoscope system, carpal canal pressure was reduced to within the normal control range. Clinical symptoms of carpal tunnel syndrome improved in all 55 hands. Postoperative electrophysiologic data remained within normal range in patients who agreed to receive electrophysiologic examinations.

Three-loop technique for A2 pulley reconstruction

A three-loop technique of secondary A2 pulley reconstruction has been developed by the authors. This method was applied to six fingers of six patients. The average follow-up period was 21 months and ranged from a minimum of 9 months to a maximum of 3 years. Total active motion of metacarpophalangeal, proximal interphalangeal, and distal interphalangeal joints improved by 30 degrees on the average from the preoperative 175 degrees to the postoperative 205 degrees. Similarly, tip palm distance showed an improvement of 10 mm on the average from the preoperative 32 mm to the postoperative 22 mm. Satisfactory grip functions were restored for all patients after the secondary pulley reconstruction.

Effects of endoscopic release of the transverse carpal ligament on carpal canal volume

Ten hands in 10 patients with carpal tunnel syndrome were treated by subcutaneous transverse carpal ligament release using the Universal Subcutaneous Endoscope system. We analyzed the morphologic changes of the carpal canal with magnetic resonance imaging (0.064 T) before and after the operation. The axial plane, which includes the beak of the trapezium and the hook of the hamate, was selected for analysis. The soft tissue boundaries of the carpal canal were outlined at the plane. The cross-sectional area of the carpal canal was 232 +/- 49 mm2 before surgery and 320 +/- 108 mm2 after surgery. There was a 33% +/- 15% increase of the carpal canal cross-section after transverse carpal ligament release. The transverse carpal ligament became more outwardly convex after the operation. The endoscopic procedure is effective for increasing the cross-sectional area and volume of the carpal canal.

Polylactide screws in acetabular osteotomy: 28 dysplastic hips followed for 1 year

Absorbable polylactide screws were used for internal fixation of rotational acetabular osteotomy (RAO) in 28 dysplastic hips. No cast was used and the patients were allowed to walk with partial weight bearing 1 month after surgery. Clinical and radiographic results were evaluated after 14 (6-24) months. Union occurred in all cases within 4 months without displacement of the osteotomy. No foreign-body inflammatory reaction on radiographs was observed, nor were there any local reactions, such as redness or swelling. Polylactide screws seem to provide sufficient strength for the internal fixation of RAO. Further observation is necessary to identify any late foreign body reaction.

Discoid medial meniscus.

A discoid medial meniscus is an extremely rare anomaly. We present 4 cases of symptomatic discoid medial meniscus. Furthermore, magnetic resonance imaging (MRI) of the unaffected knee was obtained in 3 cases, and 1 patient had bilateral discoid medial menisci as well as a unilateral discoid lateral meniscus proven by MRI. Another patient had bilateral discoid medial menisci. In one of the other 2 cases, an MRI of the unaffected knee was not obtained. However, in the involved knees of both cases, medial and lateral menisci were discoid. The incidence of bilateral discoid medial menisci is unknown. In the past, the diagnosis of a discoid meniscus was made with an arthrogram or at arthrotomy. Therefore, whether some of the unilateral cases reported in the literature might have been bilateral is unknown. The reported prevalence of bilateral discoid medial menisci will probably increase, because when a discoid medial meniscus is encountered currently, an MRI is used to find knee disorders, including in the contralateral knee. Axial multiplanar gradient-recalled-echo imaging could provide images of the discoid meniscus, depicted in its entirety in one section. This would make the recognition of a discoid meniscus simple.

Transient osteoporosis of the hip. Magnetic resonance imaging.

Magnetic resonance (MR) images of seven hips were reviewed in six patients with transient osteoporosis of the hip. The MR images of the affected joint showed increased joint fluid and diffuse signal abnormalities in the marrow of the femoral head, corresponding to a decreased signal intensity on T1-weighted images and an increased signal intensity on T2-weighted images. The MR images at the time of clinical improvement showed regression of the abnormalities. These MR abnormalities reflect the pathophysiology of this condition.