Nobuyuki Okui

Clinical, Radiographic, and Arthroscopic Outcomes After Ulnar Shortening Osteotomy: A Long-Term Follow-Up Study

PURPOSE Previous studies have investigated the long-term outcomes of ulnar shortening osteotomy (USO) in the treatment of ulnocarpal abutment syndrome (UCA), but none have used arthroscopic assessments. The purpose of this study was to investigate the long-term clinical outcomes of USO with patient-based, arthroscopic, and radiographic assessments. METHODS We retrospectively reviewed 30 patients with UCA after a minimum follow-up of 5 years, with arthroscopic evaluations at the time of both USO and plate removal. We confirmed the initial diagnosis of UCA by radiography and arthroscopy. Mean age at the time of index surgery was 37 years. Mean duration of follow-up was 11 years (range, 5-19 y). We obtained Disabilities of the Arm, Shoulder, and Hand and Hand20 self-assessments postoperatively for all patients. Bony spur formation was evaluated postoperatively from plain radiographs. RESULTS We detected triangular fibrocartilage complex (TFCC) disc tear in 13 wrists arthroscopically at the time of USO. Of these, 10 showed no evidence of TFCC disc tear at second-look arthroscopy. The remaining 17 cases showed no TFCC disc tear at either first- or second-look arthroscopy. Follow-up radiography revealed that bony spurs at the distal radioulnar joint had progressed in 13 wrists. Disabilities of the Shoulder, Arm, and Hand and Hand20 scores did not significantly correlate with the presence of bony spurs or TFCC disc tears. Range of motion decreased significantly with age only. Lower grip strength correlated with bony spur and lower radial inclination. Triangular fibrocartilage complex tear, male sex, and advanced age were associated with lower Disabilities of the Shoulder, Arm, and Hand and Hand20 scores. CONCLUSIONS Ulnar shortening osteotomy achieved excellent long-term results in most cases. Most TFCC disc tears identified at the initial surgery had healed by long-term arthroscopic follow-up. We suggest that UCA with a TFCC disc tear is a good indication for USO.

Trophic Effects of Dental Pulp Stem Cells on Schwann Cells in Peripheral Nerve Regeneration

Recently, mesenchymal stem cells have demonstrated a potential for neurotrophy and neurodifferentiation. We have recently isolated mobilized dental pulp stem cells (MDPSCs) using granulocyte-colony stimulating factor (G-CSF) gradient, which has high neurotrophic/angiogenic potential. The aim of this study is to investigate the effects of MDPSC transplantation on peripheral nerve regeneration. Effects of MDPSC transplantation were examined in a rat sciatic nerve defect model and compared with autografts and control conduits containing collagen scaffold. Effects of conditioned medium of MDPSCs were also evaluated in vitro. Transplantation of MDPSCs in the defect demonstrated regeneration of myelinated fibers, whose axons were significantly higher in density compared with those in autografts and control conduits only. Enhanced revascularization was also observed in the MDPSC transplants. The MDPSCs did not directly differentiate into Schwann cell phenotype; localization of these cells near Schwann cells induced several neurotrophic factors. Immunofluorescence labeling demonstrated reduced apoptosis and increased proliferation in resident Schwann cells in the MDPSC transplant compared with control conduits. These trophic effects of MDPSCs on proliferation, migration, and antiapoptosis in Schwann cells were further elucidated in vitro. The results demonstrate that MDPSCs promote axon regeneration through trophic functions, acting on Schwann cells, and promoting angiogenesis.

Sonography-guided Arthroscopy for Wrist Ganglion

PURPOSE To describe how to combine the complementary features of sonography and arthroscopy to make the arthroscopic resection of wrist ganglions a safer and more reliable surgery. METHODS A total of 22 patients with wrist ganglions had sonography-assisted arthroscopic resection. Sonographic visualization of ganglions, adjacent structures (ie, vessels, nerves, and tendons), and the cycling tip of the arthroscopic shaver was assessed. Arthroscopic visualization of the ganglions or ganglion stalk was also assessed. Clinical outcome measures included wrist range of motion, grip strength, and our patient-rated Hand 20 questionnaire. RESULTS Sonographic visualization of the ganglion stalk, adjacent structures, and the cycling tip of the arthroscopic shaver was possible in all 22 cases. However, ganglion stalks were visualized by arthroscopy in only 4 cases. The mean range of motion and grip strength were not significantly changed following surgery. However, the mean Hand 20 score was significantly improved from 17 to 6 at final follow-up. Ganglion recurrence was seen in 2 cases at 6 and 8 months after surgery. CONCLUSIONS Sonography-guided wrist arthroscopy provides several advantages for surgeons, including visualization of the ganglions and ganglion stalk, as well as of the arthroscopic shaver and adjacent structures such as nerves, vessels, and tendons to perform surgery safely.

Novel polysaccharide-derived hydrogel prevents perineural adhesions in a rat model of sciatic nerve adhesion.

We investigated the effects of a novel carboxymethylcellulose (CMC)‐derived hydrogel, in which phosphatidylethanolamine (PE) was introduced into the carboxyl groups of CMC, for preventing perineural adhesion after extensive internal neurolysis of rat sciatic nerve. Sciatic nerves were randomly assigned to one of the following groups: the Control group, operated but no treatment; the HA group, operated and treated with 1% hyaluronan; the CMC–PE(L) group, operated and treated with low‐viscosity CMC–PE hydrogel; and the CMC–PE(H) group, operated and treated with high‐viscosity CMC–PE hydrogel. Perineural adhesions were evaluated at 6 weeks. Nerves were also subjected to biomechanical testing to assess ultimate breaking strength. Electrophysiological and wet muscle weight measurements were performed. Breaking strengths were significantly lower for the CMC–PE(L) group than for the Control and HA groups. Latency was significantly longer for the Control group than for the CMC–PE(L) group at 20 days. The mean percentage of wet muscle weight to body weight was significantly lower for the Control group than for the CMC–PE(L) group at 6 weeks. Low‐viscosity CMC–PE hydrogel appears to prevent perineural adhesions and allow early restoration of nerve function.

Regeneration of the perineurium after microsurgical resection examined with immunolabeling for tenascin-C and alpha smooth muscle actin

The regenerative process of the perineurium and nerve function were examined using an in vivo model of perineurium resection in the rat sciatic nerve. Our hypothesis is that the regenerative process of the perineurium can be demonstrated by immunolabeling for tenascin‐C and alpha smooth muscle actin after microsurgical resection of the perineurium in vivo. A total of 38 Lewis rats were used. Eight‐week‐old animals were assigned to one of two groups: the epi‐perineurium removal group or the sham group. Under operative microscopy, the sciatic nerve was dissected from surrounding tissues at the thigh level from the ischial tuberosity to the fossa poplitea. The epi‐perineurium was carefully removed by cutting circumferentially and stripping distally for 15 mm. For CatWalk® dynamic gait analysis, only right sciatic nerves underwent surgery; the left sciatic nerves were left intact. For pathological and electrophysiological tests, both the right and left sciatic nerves underwent surgery. Analysis of data was performed at each time interval with a two‐group t‐test. P < 0.05 was considered statistically significant. After resection of a 15‐mm section of the epi‐perineurium, immediate endoneurial swelling occurred in the outer portion and spread into the central portion. Although demyelination and axonal degeneration were found in the swollen area, remyelination and recovery of electrophysiological function were seen after regeneration of the perineurium. An immunohistological and electron microscopic study revealed that the perineurium regenerated via fusion of the residual interfascicular perineurium and endoneurial fibroblast‐like cells of mesenchymal origin. CatWalk gait analysis showed not only motor paresis but also neuropathic pain during the early phases of this model.

Development and validation of a ten-item questionnaire with explanatory illustrations to assess upper extremity disorders: favorable effect of illustrations in the item reduction process

BackgroundThe purpose of this study is to develop a short and valid measure for upper extremity disorders and to assess the effect of attached illustrations in item reduction of a self-administered disability questionnaire while retaining psychometric properties.MethodsA validated questionnaire used to assess upper extremity disorders, the Hand20, was reduced to ten items using two item-reduction techniques. The psychometric properties of the abbreviated form, the Hand10, were evaluated on an independent sample that was used for the shortening process.ResultsValidity, reliability, and responsiveness of the Hand10 were retained in the item reduction process. It was possible that the use of explanatory illustrations attached to the Hand10 helped with its reproducibility. The illustrations for the Hand10 promoted text comprehension and motivation to answer the items. These changes resulted in high acceptability; more than 99.3% of patients, including 98.5% of elderly patients, could complete the Hand10 properly.ConclusionThe illustrations had favorable effects on the item reduction process and made it possible to retain precision of the instrument. The Hand10 is a reliable and valid instrument for individual-level applications with the advantage of being compact and broadly applicable, even in elderly individuals.

A new nerve coaptation technique using a biodegradable honeycomb‐patterned film

We developed a biodegradable poly‐lactide (PLA) film with a honeycomb‐patterned porous structure (honeycomb film). This study investigated the use of this film in neurorrhaphy. Three types of PLA film were tested following bilateral sciatic nerve transection and neurorrhaphy in 35 rats: 7‐ and 10‐μm thick honeycomb films, and cast film with no porous structures. Initially, following two‐stitch neurorrhaphy, 40 limbs (20 rats) underwent wrapping in 7‐ or 10‐μm honeycomb film, cast film, no wrapping, or extra two‐stitch neurorrhaphy (8 limbs each). Breaking strength was tested 2 days postoperatively. Another 30 limbs (15 rats) then underwent wrapping in 7‐ or 10‐μm honeycomb film, cast film, no wrapping, or sham operation (six limbs each). Histological and functional analyses were performed 6 weeks postoperatively. Breaking strength was significantly higher for the 10‐μm honeycomb film than for no wrapping (P = 0.013), although no significant difference was observed between the 7‐μm honeycomb and no wrapping (P = 0.085). Breaking strength for the cast film was almost equal to that for no wrapping (P = 0.994). Extra two‐stitch (four‐stitch) neurorrhaphy was significantly stronger than all groups, except the 10‐μm honeycomb group. No significant difference was observed between the 10‐μm honeycomb and the four‐stitch (P = 0.497). No negative effects on functional recovery were identified. No adhesions or inflammation were observed between the film and surrounding tissues in the honeycomb groups. Honeycomb film may offer a suitable reinforcing material for adhesion‐free neurorrhaphy.

Cubital tunnel syndrome caused by amyloid elbow arthropathy in long-term hemodialysis patients: report of 4 cases.

Carpal tunnel syndrome occurs frequently in long-term hemodialysis patients. However, the literature contains few detailed reports of other nerve entrapment syndromes of the upper extremity in these patients. We encountered 4 cases in which cubital tunnel syndrome occurred in long-term hemodialysis patients. In all cases, a hypertrophic synovial mass projecting from the humeroulnar joint compressed the ulnar nerve, and Congo red staining revealed that the mass contained amyloid deposition. Synovial proliferation resulting from amyloid arthropathy of the elbow joint appears to be the primary cause of this disease.

Arthroscopic findings of Kienbock's disease

PurposeKienböck’s disease affects the lunate bone, and osteoarthritic changes progress as the disease advances; however, relatively few studies have reported the arthroscopic findings of Kienböck’s disease, and these reports have been in small populations. The purpose of this study was to review arthroscopic findings in a larger population than studied in previous reports.MethodsWe retrospectively reviewed 57 patients who underwent radial osteotomy for Kienböck’s disease after arthroscopy of both the radiocarpal and midcarpal joints. All arthroscopic findings were classified as follows in terms of the location of osteoarthritic changes: lunate fossa of the radius, proximal/distal surface of the lunate bone, and capitate head. Radiological stages were classified according to the modified Lichtman’s classification system.ResultsAll but two patients had cartilage lesions in the proximal lunate cartilage. Older patients had significantly more cartilage lesions, but radiological stage showed no correlation with the number of cartilage lesions.ConclusionsThis study demonstrated that the proximal lunate bone was affected in most cases of Kienböck’s disease and that older patients had more cartilage lesions.

Painful Snapping Elbow in Patients With Congenital Radioulnar Synostosis: Report of Two Cases

Two patients with congenital radioulnar synostosis presented with painful snapping on elbow motion in one case and locking of the elbow joint in the other. Elbow arthroscopy revealed the presence of tight fibrous tissue trapping the radial head. Arthroscopic removal of this tight fibrous tissue resulted in painless joint motion without recurrence of snapping or locking.