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Biomedical subjects

Moon Sang Chung

Publications and source records attributed to Moon Sang Chung.

12 recordsLinked to original sources

Abnormal triangular epiphysis causing angular deformity of the thumb.

PURPOSE: To present a triangular-shaped abnormal secondary ossification center of the distal phalanx causing angular deformity of the thumb and the surgical outcome of corrective closing-wedge osteotomy for this deformity. METHODS: We treated 6 patients with abnormal triangular epiphysis in the distal phalanx of the thumb, including 3 bilateral cases. The average age was 43 months and there were 2 boys and 4 girls. Of the 9 thumbs intraepiphyseal closing-wedge osteotomy was performed in 5 and proximal phalangeal closing-wedge osteotomy was performed in 4. We measured the deformities in degrees of angulation and the range of motion of the interphalangeal (IP) joint. The average duration of the follow-up period was 27 months after the surgery. RESULTS: Preoperative angular deformity of ulnar deviation averaged 30 degrees , which was reduced to an average of 12 degrees after osteotomy at the last follow-up assessment. All osteotomies healed and there was no evidence of physeal or articular damage. Interphalangeal joint range of motion did not decrease after surgery in all cases. Patients and parents were satisfied with the results of the surgery, although mild deformity persisted in the interphalangeal joint when in the flexed position after proximal phalangeal osteotomy. CONCLUSIONS: Abnormal triangular epiphysis causing angled thumb is different from delta bone and can be treated with either intraepiphyseal or proximal phalangeal closing-wedge osteotomy. The intraepiphyseal procedure, however, could achieve better deformity correction regardless of the interphalangeal joint position. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic, Level IV.

Child, Preschool↗

Innervated lateral middle phalangeal finger flap for a large pulp defect by bilateral neurorrhaphy.

BACKGROUND: The dorsal middle phalangeal finger flap is a reliable flap. However, it requires skin grafting on the whole surface of the dorsum of the middle phalanx of the donor finger for an exposed extensor tendon and leaves a conspicuous contour deformity at the donor site. In an effort to overcome this problem, the authors have been using a heterodigital innervated lateral middle phalangeal finger flap for resurfacing sizable defects of the pulp. METHODS: Flaps were designed on the lateral ulnar side of the middle finger for five thumb defects and the ring finger for two little finger defects. To provide sensation to the flap, one nerve fascicle from the direct small branches of the proper digital nerve after interfascicular dissection (palmar aspect of the flap) and the dorsal branch of the proper digital nerve (dorsal aspect) were identified and sectioned proximally, leaving a 1-cm nerve tail attached to the flap. RESULTS: These flaps provided sensate coverage with static two-point discrimination values of approximately 6 mm. Donor finger morbidity was minimal, and pulp sensation in donor fingers was normal in all cases. No donor finger cold intolerance was reported in this series. CONCLUSIONS: This described flap supplies glabrous skin of nearly normal sensibility. One nerve fascicle from the direct small branches of the proper digital nerve and the dorsal branch of the proper digital nerve were used for maximal sensation. Donor fingers are cosmetically better than those of dorsal middle phalangeal finger flaps because the grafted skin is hidden by an adjacent finger.

Adult↗

Ulnar shortening osteotomy in idiopathic ulnar impaction syndrome. Surgical technique.

BACKGROUND: Idiopathic ulnar impaction syndrome can be defined as a degenerative condition of the ulnar aspect of the wrist in patients with congenital or dynamic positive ulnar variance without a history of fracture or premature physeal arrest. The purpose of this study was to evaluate the clinical features of idiopathic ulnar impaction syndrome and the outcomes of ulnar shortening osteotomy for this group of patients. METHODS: Thirty-one wrists in twenty-nine patients with idiopathic ulnar impaction syndrome were treated with an ulnar shortening osteotomy. Ulnar variance was measured on an anteroposterior radiograph of the wrist, and radioulnar distance was measured on a lateral radiograph, with the forearm in neutral rotation, to evaluate any displacement of the ulnar head from the distal aspect of the radius. All patients were followed clinically and radiographically for a mean of thirty-two months. RESULTS: An average preoperative ulnar variance of +4.6 mm (range, 2 to 7.5 mm) was reduced to an average of -0.7 mm (range, -4 to +1 mm) postoperatively. Preoperatively, the modified Gartland and Werley score was an average (and standard deviation) of 69.5 +/- 7.6, with twenty-four wrists rated poor and seven rated fair. Postoperatively, the score improved to an average of 92.5 +/- 8.0, with twenty-four wrists rated excellent; five, good; one, fair; and one, poor. Dorsal subluxation of the distal aspect of the ulna was found concomitantly in nine wrists, and it was found to be reduced by the shortening osteotomy. Seven patients had cystic changes in the carpal bones preoperatively, but these were not evident one to two years after the operation. CONCLUSIONS: Ulnar shortening osteotomy improved wrist function in patients with idiopathic ulnar impaction syndrome and reduced the subluxation of the distal radioulnar joint, which is commonly found in these patients. Degenerative cystic changes of the ulnar carpal bones appear to resolve following the shortening osteotomy.

Adolescent↗

Ulnar shortening osteotomy in idiopathic ulnar impaction syndrome.

BACKGROUND: Idiopathic ulnar impaction syndrome can be defined as a degenerative condition of the ulnar aspect of the wrist in patients with congenital or dynamic positive ulnar variance without a history of fracture or premature physeal arrest. The purpose of this study was to evaluate the clinical features of idiopathic ulnar impaction syndrome and the outcomes of ulnar shortening osteotomy for this group of patients. METHODS: Thirty-one wrists in twenty-nine patients with idiopathic ulnar impaction syndrome were treated with an ulnar shortening osteotomy. Ulnar variance was measured on an anteroposterior radiograph of the wrist, and radioulnar distance was measured on a lateral radiograph, with the forearm in neutral rotation, to evaluate any displacement of the ulnar head from the distal aspect of the radius. All patients were followed clinically and radiographically for a mean of thirty-two months. RESULTS: An average preoperative ulnar variance of +4.6 mm (range, 2 to 7.5 mm) was reduced to an average of -0.7 mm (range, -4 to +1 mm) postoperatively. Preoperatively, the modified Gartland and Werley score was an average (and standard deviation) of 69.5 +/- 7.6, with twenty-four wrists rated poor and seven rated fair. Postoperatively, the score improved to an average of 92.5 +/- 8.0, with twenty-four wrists rated excellent; five, good; one, fair; and one, poor. Dorsal subluxation of the distal aspect of the ulna was found concomitantly in nine wrists, and it was found to be reduced by the shortening osteotomy. Seven patients had cystic changes in the carpal bones preoperatively, but these were not evident one to two years after the operation. CONCLUSIONS: Ulnar shortening osteotomy improved wrist function in patients with idiopathic ulnar impaction syndrome and reduced the subluxation of the distal radioulnar joint, which is commonly found in these patients. Degenerative cystic changes of the ulnar carpal bones appear to resolve following the shortening osteotomy.

Adolescent↗

Distally based lateral supramalleolar adipofascial flap for reconstruction of the dorsum of the foot and ankle.

Soft-tissue reconstruction of the dorsum of the foot and ankle has long been a challenge for reconstructive surgeons. Limitations in the available local tissue and donor-site morbidity restrict the options. In an effort to solve these difficult problems, the authors have begun to use a distally based lateral supramalleolar adipofascial flap. This report presents the authors' early experience with seven patients treated with this flap. The patients' ages ranged from 5 to 26 years; four of the patients were male and three were female. The cause of the soft-tissue defects involved acute trauma and chronic scar contracture. The flap and the adjoining raw area were covered with a full-thickness skin graft, and the donor site at the lateral aspect of the leg was closed primarily without grafting. A skin graft was taken from the groin area, which was closed primarily. Compared with the other flaps, this adipofascial flap was thinner and produced less bulkiness to the recipient site and minor aesthetic sequelae to the donor site. It is believed that this flap is versatile and effective and is a good addition to the available techniques used by reconstructive surgeons for coverage of the dorsum of the foot and ankle.

Accidents, Traffic↗

Intramuscular lipoma in thenar or hypothenar muscles.

We report on six patients of intramuscular lipoma of the hand. Four of them occurred in the thenar muscles and two in the hypothenar muscles. The mean age was 49 years (7-68 years). The duration of the lesions prior to excision was averaged as 35 months (12-60 months). Preoperative MRI was taken in all patients, and it was very useful for the diagnosis and differentiation between four well-circumscribed types and two infiltrative types. All operations were performed under loupe magnification. Preoperatively four patients with thenar lipoma had difficulty in moving their thumbs. Two out of four patients with lipomas in the thenar muscles had preoperative intermittent paresthesia and hyperesthesia caused by compression of the radial digital nerve of the thumb. Two patients with lipoma in the hypothenar eminence complained of difficulty with strong grip. The average diameter of the thenar group in its longest dimension was 5.2 cm (3-7 cm), and those of the hypothenar group was 5.5 cm (4-7 cm). At a mean follow-up of 55 months (21-91 months), no tumour had recurred.

Aged↗

Evaluation of pedicle screw position on computerized tomography scans. Technical note.

The quality of a computerized tomography (CT) scan is significantly reduced by metal artifact caused by a pedicle screw system. The purpose of this study was to develop a method of facilitating the evaluation of pedicle screw position on CT scans obtained after screw insertion. The authors developed an algorithm to process spiral CT scans in a personal computer. This uses a digital image enhancement technique, the curve change-based intensity transformation algorithm. This method can generate a clear image of the screw outlines while reducing metal artifact. The resulting images are displayed in arbitrary planes as well as in axial, coronal, and sagittal planes, to support better the evaluation of pedicle screw position. The algorithm was tested using CT scans obtained in 37 patients in whom 186 pedicle screws had been placed. There were five types of screw systems, all of which were made of titanium alloys. In all cases algorithm-based determination of screw position became more convenient and more accurate than when using the conventional bone window setting. In addition, it provided better soft-tissue visualization than the bone window. The software, by displaying clear outlines of screws and decreasing metal artifact, as well as by reconstructing the images in arbitrary planes, was more helpful in identifying the position of pedicle screws than the conventional bone window setting.

Artifacts↗

Comparative study between minimal medial epicondylectomy and anterior subcutaneous transposition of the ulnar nerve for cubital tunnel syndrome.

The purpose of this study was to review the results of 2 surgical methods for treating cubital tunnel syndrome. From 1994 to 2001, minimal medial epicondylectomy was performed on 22 elbows, and anterior subcutaneous transposition of the ulnar nerve was done on 34 elbows. In the group treated by medial epicondylectomy, 9 of the results (41%) were excellent, 10 (45%) were good, 2 (9%) were fair, and 1 result (5%) was poor. In the group treated by anterior subcutaneous transposition of ulnar nerve, 14 of the results (41%) were excellent, 13 (38%) were good, 6 (18%) were fair, and 1 result (3%) was poor. No significant difference was found between the 2 groups (P < .05). Both methods can be used for the treatment of cubital tunnel syndrome with a high rate of satisfaction.

Adult↗

Three-dimensional corrective osteotomy for cubitus varus in adults.

In 23 adult patients, cubitus varus deformity was corrected by 3-dimensional osteotomy. During surgery, not only varus but internal rotation, flexion-extension deformity of the elbow, and lateral protrusion of the distal fragment were simultaneously addressed. The mean age of the patients was 26 years. Three showed tardy ulnar nerve palsy. The follow-up period after osteotomy averaged 1 year 10 months. The humeral-elbow-wrist angle improved from a mean 26 degrees of varus preoperatively to a mean of 3 degrees of valgus postoperatively. The mean internal rotation angle improved from 25 degrees to 5 degrees. As there was no recurrence of the deformity, this method of 3-dimensional corrective osteotomy for the treatment of cubitus varus in skeletally mature adults is recommended.

Adolescent↗