Published papers

Simple decompression of the ulnar nerve at the elbow has not been shown to reduce nerve strain in cadavers. In this study, ulnar nerve strain at the elbow was measured intraoperatively in 11 patients with cubital tunnel syndrome, before and after simple decompression. Statistical analysis was performed using a paired Student's t-test. Mean ulnar nerve strain before and after simple decompression was 30.5% (range 9% to 69%) and 5.5% (range -2% to 11%), respectively; this difference was statistically significant (p < 0.01) with a statistical power of 96%. Simple decompression reduced ulnar nerve strain in all patients by an average of 24.5%. Our results suggest that the pathophysiology of cubital tunnel syndrome may be multifactorial, being neither a simple compression neuropathy nor a simple traction neuropathy, and simple decompression may be a favourable surgical procedure for cubital tunnel syndrome in terms of decompression and reduction of strain in the ulnar nerve. © The Author(s) 2012.

TNFα-converting enzyme (TACE) is a membrane-bound proteolytic enzyme with essential roles in the functional regulation of TNFα and epidermal growth factor receptor (EGFR) ligands. Previous studies have demonstrated critical roles for TACE in vivo, including epidermal development, immune response, and pathological neoangiogenesis, among others. However, the potential contribution of TACE to skeletal development is still unclear. In the present study, we generated a Tace mutant mouse in which Tace is conditionally disrupted in chondrocytes under the control of the Col2a1 promoter. These mutant mice were fertile and viable but all exhibited long bones that were approximately 10% shorter compared to those of wild-type animals. Histological analyses revealed that Tace mutant mice exhibited a longer hypertrophic zone in the growth plate, and there were fewer osteoclasts at the chondro-osseous junction in the Tace mutant mice than in their wild-type littermates. Of note, we found an increase in osteoprotegerin transcripts and a reduction in Rankl and Mmp-13 transcripts in the TACE-deficient cartilage, indicating that dysregulation of these genes is causally related to the skeletal defects in the Tace mutant mice. Furthermore, we also found that phosphorylation of EGFR was significantly reduced in the cartilage tissue lacking TACE, and that suppression of EGFR signaling increases osteoprotegerin transcripts and reduces Rankl and Mmp-13 transcripts in primary chondrocytes. In accordance, chondrocyte-specific abrogation of Egfr in vivo resulted in skeletal defects nearly identical to those observed in the Tace mutant mice. Taken together, these data suggest that TACE-EGFR signaling in chondrocytes is involved in the turnover of the growth plate during postnatal development via the transcriptional regulation of osteoprotegerin, Rankl, and Mmp-13. © 2013 Saito et al.

A case of radial and volar perilunate trans-scaphoid fracture dislocation in which the proximal fragment of the scaphoid was dislocated dorsally is presented.

Objective: To investigate usefulness of osteochondral grafting from the costo-osteochondral junction as a repair technique for articular cartilage defects histologic and biochemical analysis of grafted cartilage in rabbit knees was evaluated up to 48. weeks after transplantation. Methods: Twenty New Zealand White rabbits were used. A costal osteochondral plug was harvested from a middle rib. After trimming, it was transplanted into a cylindrical osteochondral 2.5. mm diameter and 5. mm deep defect created in the knee. The animals were sacrificed at 6, 12, 24, and 48. weeks after transplantation. Defect sites were inspected macroscopically, and then by light microscopy. Samples were evaluated for cell viability using a fluorescent. in situ double-staining protocol with confocal laser microscopic analysis. Samples were also processed to assess type I and II collagen and aggrecan mRNA expression using reverse transcription-polymerase chain reaction (RT-PCR). Results: Histologically, bone union was achieved in all plugs. Confocal microscopic analysis revealed chondrocyte viability in the 48-week grafts; the distribution of chondrocytes was similar to surrounding articular cartilage. The expression of type II collagen and aggrecan mRNA in the grafted cartilage was consistent with normal articular cartilage and normal costal cartilage. These results were observed over 6-48. weeks. Conclusions: Our study revealed that chondrocytes in the grafted cartilage were viable at least up to 48. weeks and that mRNA expression of type II collagen and aggrecan was also similar to that of normal articular cartilage. These results suggest that costal osteochondral grafting can be a useful alternative in the treatment of osteochondral defects. © 2011 Osteoarthritis Research Society International.

We report a case of avulsion of the flexor digitorum profundus secondary to recurrent enchondroma. The tumor was curetted with bone grafting of cancellous bone from the distal radius, and the fragment avulsed by the flexor digitorum profundus tendon was fixed to its original site using a pullout suture through the distal phalanx to the nail. The lesion healed and function recovered 6 years after surgery.

Locking of the metacarpophalangeal joints has been occasionally reported in older adults, but reports of this problem are rare in younger individuals. We report 8 young adult patients with a metacarpophalangeal joint locked in 90° flexion after minor trauma. The cases included 6 little fingers and 2 thumbs in 1 male and 7 female patients aged 16 to 39 years. All were easily reduced closed. We postulate the mechanism of injury. Type of study/level of evidence: Therapeutic IV. © 2011 American Society for Surgery of the Hand.

Because the radioulnar ligament attaches to the ulnar fovea and base of the ulnar styloid, foveal detachment of the triangular fibrocartilage complex (TFCC) induces severe distal radioulnar joint instability. This article describes both an arthroscopic and open repair technique to reattach the TFCC to the fovea. Both techniques reanchor the detached TFCC to the fovea. Both techniques are reliable and promising techniques in the repair of a foveal detachment of the TFCC. © 2011 Elsevier Inc.

We report the case of a 43-year-old man with steroid-induced osteonecrosis of the distal humerus in both arms. Costal osteochondral autografts were used to restore both joints with satisfactory outcomes. © 2011 American Society for Surgery of the Hand.

We present a case of post-traumatic osteonecrosis of the radial head in a 13-year-old boy which was treated with costo-osteochondral grafts. A satisfactory outcome was seen at a follow-up of two years and ten months. Although costo-osteochondral grafting has been used in the treatment of defects in articular cartilage, especially in the hand and the elbow, the extension of the technique to manage post-traumatic osteonecrosis of the radial head in a child has not previously been reported in the English language literature. Complete relief of pain was obtained and an improvement in the range of movement was observed. The long-term results remain uncertain. ©2011 British Editorial Society of Bone and Joint Surgery.

We retrospectively defined the rate and clinical features of tendon entrapment in 693 consecutive patients with 701 distal radius fractures treated in a single hospital. Eight extensor tendons and one flexor tendon were entrapped. All fractures with extensor tendon entrapment were palmarly displaced (Smith type) or epiphyseal. Flexor tendon entrapment was seen in dorsally angulated (Colles type) epiphyseal fracture. The rate of tendon entrapment in acute distal radius fractures was 1.3%. Extensor tendon entrapment in palmarly displaced fractures is more common. © 2009 The British Society for Surgery of the Hand. Published by SAGE. All rights reserved.

Purpose: To retrospectively analyze consecutive cases with opening wedge corrective osteotomy of the volarly malunited distal radius with iliac bone graft, including preoperative and postoperative comparison of symptoms, visual analog scale (VAS), Japanese Society for Surgery of the Hand version of the Disabilities of the Arm, Shoulder, and Hand (DASH-JSSH) questionnaires, radiographic indices, clinical results as evaluated by modified Mayo wrist score, and complications. Methods: Subjects were 28 patients with volarly malunited distal radius fracture treated by transverse opening wedge osteotomy with oblique iliac bone graft. Preoperative symptoms included wrist deformity, weakness of grip strength, and marked restriction of supination range. Postoperative symptoms, radiographic parameters, clinical results, and complications were analyzed at an average of 25 months of follow-up. We also analyzed the union period of the radius in younger patients (≤45 years old) and older patients (>45 years old). Results: Mean preoperative visual analog scale was 45, improving significantly to 3 postoperatively. Range of wrist motion improved in all 28 patients, with supination range improving from 16° preoperatively to 80° postoperatively. Mean preoperative DASH-JSSH score was 55, improving to 9 postoperatively. Radiography revealed that volar tilt improved from 32° preoperatively to 10° postoperatively, and radial inclination increased from 17° to 21°. Preoperative ulnar variance of +5.9 mm was corrected to -0.1 mm postoperatively. All 28 wrists demonstrated bony union at the osteotomy site after an average of 52 days (younger patients, 51 days; older patients, 54 days). No complications, significant radiographic correction loss, or nonunion were seen after at least 2 years of follow-up. Modified Mayo wrist score was excellent in 16 patients, good in 10 patients, and fair in 2 patients. Conclusions: Opening wedge osteotomy for volarly malunited distal radius fracture restored bony configuration of the distal radius, decreased pain, and improved grip strength and range of wrist motion, particularly for forearm supination. No complications or noteworthy correction loss were noted after surgery, even in older patients. Type of study/level of evidence: Therapeutic IV. © 2009 American Society for Surgery of the Hand.

The in vitro culture of porcine bone marrow-derived mesenchymal stem cells (MSCs) was used for the investigation of adult stem cell biology. Isolated porcine MSCs possessed the ability to proliferate extensively in an antioxidants-rich medium containing 5% fetal bovine serum (FBS). Greater than 40 serial MSC passages and 100 cell population doublings have been recorded for some MSC batches. Early and late passage MSCs were defined here as those cultures receiving less than 5 trypsin passages and more than 15 trypsin passages, respectively. Consistent with their robust ability to proliferate, both the early and late passage MSCs expressed the cell-cycle promoting enzyme p34cdc2 kinase. Late MSCs, however, exhibited certain features reminiscent of cellular aging such as actin accumulation, reduced substrate adherence, and increased activity of lysosomal acid β-galactosidase. Early MSCs retained the multipotentiality capable of chondrogenic, osteogenic, and adipogenic differentiation upon induction in vitro. In contrast, late MSCs were only capable of adipogenic differentiation, which was greatly enhanced at the expense of the osteochondrogenic potential. Along with these changes in multipotentiality, late MSCs expressed decreased levels of the bone morphogenic protein (BMP-7) and reduced activity of alkaline phosphatase. Late MSCs also exhibited attenuated synthesis of the hematopoietic cytokines granulocyte colony-stimulating factor (G-CSF), leukemia inhibitory factor (LIF), and stem cell factor (SCF). The long-term porcine MSC culture, thus, provides a model system to study the molecular interplay between multiple MSC differentiation cascades in the context of cellular aging. © 2005 Wiley-Liss, Inc.

Open repair technique of the ulnar disruption of the triangular fibrocartilage complex is described. This technique is indicated for a fresh or a relatively fresh (less than 1 year after the initial injury) ulnar foveal detachment tear, horizontal tear, and proximal slit tear of the triangular fibrocartilage complex, all of which are accompanied by severe dorsal, palmar, or multidirectional instability of the distal radioulnar joint. A chronic tear greater than 1 year from initial injury and a fresh triangular fibrocartilage complex tear without distal radioulnar joint instability, such as central slit tear, are excluded from our indications. A dorsal C-shaped skin incision, a longitudinal incision of the radial edge of the extensor carpi ulnaris subsheath and the dorsal distal radioulnar joint capsule, exposes the distal radioulnar joint. A small, 5-mm longitudinal incision at the origin of the radioulnar ligament exposes its fovea detachment and/or the proximal slit tear of the triangular fibrocartilage complex. The disrupted radioulnar ligament is sutured in a pullout fashion to the ulna with a 3-dimensional double mattress technique through 2 bone tunnels that is precisely made at the central portion of the fovea with 1.2-mm K-wire. An additional horizontal mattress suture is used for closure of the small incision made at the radioulnar ligament, then the extensor carpi ulnaris is repaired. This open-repair technique is complex and requires precise technical skills; however, early results hav been more rewarding than the conservative treatment. © 2004 Lippincott Williams & Wilkins, Philadelphia.