Kenichi Kazuki

Palmar plating for dorsally displaced fractures of the distal radius.

Extensor tendon rupture and irritation caused by implants or surgical intervention are serious complications in the treatment of fracture of the distal radius when a dorsal approach is used. To prevent complications, the dorsally displaced fracture of the distal radius was treated using a palmar approach. The subjects were 18 men and 15 women with a mean age of 54 years at the time of the injury (range, 23–75 years). All the patients had internal fixation with a plate and screws using the palmar approach. Union was achieved in all patients. Radiographic parameters, including the palmar tilt, radial inclination, radial length, and ulnar variance have been maintained since the operation. According to the rating scale of Gartland and Werley, there were 12 excellent, 20 good, and one fair result. There were no extensor tendon injuries that occurred during use of the palmar approach in this small series of patients. Palmar plating can be safe and effective for treatment of a dorsally displaced fracture of the distal radius.

Transplantation of induced pluripotent stem cell-derived neurospheres for peripheral nerve repair.

In spite of the extensive research using induced pluripotent stem (iPS) cells, the therapeutic potential of iPS cells in the treatment of peripheral nerve injury is largely unknown. In this study, we repaired peripheral nerve gaps in mice using tissue-engineered bioabsorbable nerve conduits coated with iPS cell-derived neurospheres. The secondary neurospheres derived from mouse iPS cells were suspended in each conduit (4000,000 cells per conduit) and cultured in the conduit in three-dimensional (3D) culture for 14 days. We then implanted them in the mouse sciatic nerve gaps (5 mm) (iPS group; n=10). The nerve conduit alone was implanted in the control group (n=10). After 4, 8 and 12 weeks, motor and sensory functional recovery in mice were significantly better in the iPS group. At 12 weeks, all the nerve conduits remained structurally stable without any collapse and histological analysis indicated axonal regeneration in the nerve conduits of both groups. However, the iPS group showed significantly more vigorous axonal regeneration. The bioabsorbable nerve conduits created by 3D-culture of iPS cell-derived neurospheres promoted regeneration of peripheral nerves and functional recovery in vivo. The combination of iPS cell technology and bioabsorbable nerve conduits shows potential as a future tool for the treatment of peripheral nerve defects.

Acceleration of peripheral nerve regeneration using nerve conduits in combination with induced pluripotent stem cell technology and a basic fibroblast growth factor drug delivery system

Various modifications including addition of Schwann cells or incorporation of growth factors with bioabsorbable nerve conduits have been explored as options for peripheral nerve repair. However, no reports of nerve conduits containing both supportive cells and growth factors have been published as a regenerative therapy for peripheral nerves. In the present study, sciatic nerve gaps in mice were reconstructed in the following groups: nerve conduit alone (control group), nerve conduit coated with induced pluripotent stem cell (iPSc)-derived neurospheres (iPSc group), nerve conduit coated with iPSc-derived neurospheres and basic fibroblast growth factor (bFGF)-incorporated gelatin microspheres (iPSc + bFGF group), and autograft. The fastest functional recovery and the greatest axon regeneration occurred in the autograft group, followed in order by the iPSc + bFGF group, iPSc group, and control group until 12 weeks after reconstruction. Thus, peripheral nerve regeneration using nerve conduits and functional recovery in mice was accelerated by a combination of iPSc-derived neurospheres and a bFGF drug delivery system. The combination of all three fundamental methodologies, iPSc technology for supportive cells, bioabsorbable nerve conduits for scaffolds, and a bFGF drug delivery system for growth factors, was essential for peripheral nerve regenerative therapy.

Case of Trigger Finger Related to an Intertendinous Connection between the Flexor Tendons

We report a rare cause of trigger finger related to an anatomical variation of an intertendinous connection between the flexor digitorum superficialis and flexor digitorum profundus tendons in the palmar region.

PALMAR PLATING FOR AO/ASIF C3.2 FRACTURES OF THE DISTAL RADIUS WITH ARTHROSCOPICALLY ASSISTED REDUCTION

We performed a retrospective study of 15 patients with AO/ASIF C3.2 fracture of the distal radius. All patients were treated with arthroscopically assisted reduction of the radiocarpal joint followed by palmar plating with autologous bone graft, with a follow-up evaluation of 24 months. According to the demerit point system of Gartland and Werley, five patients had excellent results and 10 had good results. Grade 1 arthritic changes were found in 10 patients even though with no step-off on radiographs. In the current study, this combined treatment was challenging and useful for AO/ASIF C3.2 fractures.

Temporary Scaphotrapezoidal Joint Fixation for Adolescent Kienböck's Disease

PURPOSE There are few therapeutic guidelines for adolescent Kienböcks disease. The purpose of our study was to investigate the clinical and radiographic outcomes of temporary scaphotrapezoidal (ST) joint fixation for adolescent Kienböcks disease. METHODS This was a retrospective review of 6 adolescent patients with Kienböcks disease treated by temporary ST joint fixation. All patients had pain with rest and activity before surgery. The mean patient age at the time of surgery was 14 years, and final follow-up examination was at a mean of 23 months. Under general anesthesia, 2 or 3 K-wires were inserted from the dorsal trapezoid to the scaphoid. The wires were removed at 3 to 6 months. RESULTS Mean postoperative wrist extension and flexion were increased from 46 degrees and 48 degrees to 68 degrees and 77 degrees , respectively. These improvements were statistically significant compared with preoperative wrist extension and flexion. Grip strength significantly increased from 52% to 86% of the unaffected side. None of the 6 patients had postoperative pain either at rest or with activity. On final follow-up wrist x-ray films, none of the patients had sclerotic change or fragmentation of the lunate, although decreased lunate height remained in all patients. Magnetic resonance imaging revealed improvement to nearly normal intensity of the lunate on T1- and T2-weighted images in all patients. CONCLUSIONS Both clinical and radiographic outcomes of temporary ST joint fixation for adolescent Kienböcks disease were excellent. We therefore recommend this procedure for the surgical treatment of adolescent Kienböcks disease. TYPE OF STUDY/LEVEL OF EVIDENCE Therapeutic IV.

A tissue-engineered bioabsorbable nerve conduit created by three-dimensional culture of induced pluripotent stem cell-derived neurospheres

We previously reported a bioabsorbable nerve conduit coated with Schwann cells for the treatment of peripheral nerve defects. Since there have been dramatic developments in induced pluripotent stem (iPS) cells in recent years, the purpose of the present study was to create a tissue-engineered nerve conduit coated with iPS cell-derived neurospheres. Such a conduit was constructed by three-dimensional (3D)-culture of these cells using a bioabsorbable polymer conduit as a scaffold. The nerve conduit was composed of a mesh of poly L-lactide, and a porous sponge of 50% poly L-lactide and 50% poly ε-caprolactone. The primary and secondary neurospheres (PNS and SNS, respectively) induced from iPS cells were suspended in individual conduits. The conduits were incubated for 7 or 14 days in vitro and then evaluated using immunohistochemistry. All of the 7- and 14-day differentiated PNS and SNS were observed to have adhered to the inner surface of the conduits and to have migrated into the inner porous sponge. The engrafted cells were positive for anti-Tuj1, -S-100 and -GFAP antibodies, indicating that their pluripotent ability to form neural or glial cells was maintained. These findings indicate the feasibility of creating nerve conduits coated with a 3D-culture of iPS cell-derived neurospheres for the treatment of peripheral nerve defects.

Combined medialis pedis and medial plantar fasciocutaneous flaps for coverage of soft tissue defects of multiple adjacent fingers

Soft tissue defects of adjacent multiple fingers covered by a single large flap require secondary separation of the flap into each finger. Such covering obstructs independent motion of injured fingers until the single large flap is separated. This report describes the technique of combined medialis pedis and medial plantar fasciocutaneous flaps for reconstructing soft tissue defects of multiple adjacent fingers. Three male patients (age range, 18–33 years) underwent soft tissue reconstructions of multiple adjacent fingers with combined flaps. Injuries involved three adjacent palmar fingers, two adjacent palmar fingers, and two adjacent dorsal fingers. Average sizes of the combined flaps were 4.2 × 4.0 cm for the medialis pedis flap and 3.0 × 1.8 cm for the medial plantar fasciocutaneous flap. All flaps survived without vascular complications, and donor sites healed uneventfully. All patients experienced excellent recovery of range of motion for the reconstructed fingers. In conclusion, combined flaps may offer an alternative for coverage of soft tissue defects that involve multiple adjacent fingers.

Palmar plating with calcium phosphate bone cement for unstable Colles' fractures

A prospective study was done in 20 patients with unstable Colles’ fractures with metaphyseal bone defects and who were treated with palmar plating combined with injectable calcium phosphate bone cement. The patients were three men and 17 women with a mean age of 69 years (range, 65–86 years) at the time of the injury. The followup after the operation ranged from 6 to 24 months (mean, 12 months). Union was gained in all the patients. The records of radiographic parameters, including the palmar tilting angle, radial inclination, radial length, and ulnar variance had been maintained since the surgery. According to the rating scale of Gartland and Werley, 16 patients had excellent results and four had good results. There were no neurovasucular and tendon injuries as complications.

Correction of dorsi-flexed intercalated segment instability after restoration of scaphoid height in a cadaver model of scaphoid non-union

Models of scaphoid non-union with static dorsi-flexed intercalated segment instability were produced in five frozen arms from cadavers or subjects following accidents by repetitive mechanical loading of the wrist joints longitudinally after a bone defect has been made at the mid-portion of the scaphoid. We designed four models of reduction: anatomical reduction; reduction with a shortened scaphoid; anatomical reduction but with the radio-lunate ligament sectioned, and a shortened scaphoid with the radio-lunate ligament sectioned. Results suggested that anatomical reduction with rigid fixation with a Herbert screw was most effective for correction of malalignment with DISI. Preservation of the radio-lunate ligament during the palmar approach to the scaphoid seemed to be important to prevent ligamentous carpal instability.