Hitoshi Hirata

Validation of the Japanese Society for Surgery of the Hand version of the Disability of the Arm, Shoulder, and Hand questionnaire.

BackgroundThe Disability of the Arm, Shoulder and Hand (DASH) questionnaire is a region-specific self-administered questionnaire that consists of a disability/symptom (DASH-DS) scale, and two optional modules, the work (DASH-W) and the sport/music (DASH-SM) modules. The DASH was cross-culturally adapted and developed by the Impairment Evaluation Committee, Japanese Society for Surgery of the Hand. The purpose of this study was to test the reliability, validity, and responsiveness of the Japanese version of DASH (DASH-JSSH).MethodsA series of 72 patients with upper extremity disorders completed the DASH-JSSH, the medical outcomes study 36-item short-form health survey (SF-36), and the Visual Analog Scale (VAS) for pain. Thirty-eight of the patients were reassessed for test-retest reliability 1 or 2 weeks later. Reliability was investigated by reproducibility and internal consistency. To analyze the validity, a principal component analysis and correlation coefficients between the DASH-JSSH and the SF-36 were obtained. Responsiveness was examined by calculating the standardized response mean (mean change/SD) and effect size (mean change/SD of baseline value) after carpal tunnel release of the 17 patients with carpal tunnel syndrome.ResultsCronbach’s alpha coefficients in the DASH-DS and DASH-W were 0.962 and 0.967, respectively. The intraclass correlation coefficients for the same were 0.82 and 0.85, respectively. The unidimensionality of the DASH-DS and DASH-W were confirmed. The correlations between the DASH-DS score and the subscale of the SF-36 scale ranged from −0.29 to −0.73. The correlation coefficient between the DASH-DS and the DASH-W was 0.79. The standardized response mean/effect size of DASH-DS, DASH-W, and VAS for pain were −0.48/−0.26, −0.68/−0.41, and −0.40/−0.40, respectively. DASH-DS and DASH-W were as moderately sensitive as VAS for pain.ConclusionThe DASH-DS and DASH-W Japanese version have evaluation capacities equivalent to those of the original and other language versions of the DASH.

Ceramic Acetabular Liner Fracture in Total Hip Arthroplasty with a Ceramic Sandwich Cup

In total hip arthroplasty, a modular acetabular component with a sandwich insertion (alumina ceramics/polyethylene/titanium) was proposed. The polyethylene layer might reduce the rigidity of the ceramics and prevent an impingement between the ceramic liner rim and the femoral neck. A case of an acetabular liner fracture of the ceramic sandwich cup was presented. The fracture occurred 1.4 years after the operation without trauma. Because the ceramic liner rim was hit by the head following the impingement between the neck and the polyethylene, the cause of the fracture might be the stress concentration at the rim of the ceramic liner, of which the thickness was only 4 mm. At revision surgery, the fractured ceramic liner was replaced with a polyethylene liner without inner ceramic liner.

Nerve growth factor signaling of p75 induces differentiation and ceramide-mediated apoptosis in Schwann cells cultured from degenerating nerves

In peripheral nerve regeneration or remyelination, immature Schwann cells expressing p75NTR play cardinal roles in the support and regeneration of axons (Griffin JW, Hoffman PN. Peripheral Neuropathy 361–376, 1993). Only one of four to six Schwann cells participate in remyelination of damaged or regenerating axons. The rest of the cells, or supernumerary Schwann cells, show severe atrophy and gradually decrease in number, reestablishing a 1:1 axon–Schwann cell relationship (Said G, Duckett S. Acta Neuropathol (Berl) 53:173–179, 1981). Recent reports demonstrated that severely atrophied supernumerary Schwann cells are eliminated by apoptosis during axonal regeneration or remyelination (Hirata H, Hibasami H. Apoptosis 3:353–360, 1998; Berciano MT, Calle E. Acta Neuropathol (Berl) 95:269–279, 1998). The mechanism to induce selective death of supernumerary Schwann cells without causing any damage to axon‐associated Schwann cells or axons remains to be determined. In this article, we report that p75NTR, the low‐affinity receptor for all members of neurotrophins, signals both cell differentiation and apoptosis through intracellular ceramide elevation. The final response is dependent on the intracellular ceramide level and Schwann cells modulate their response by changing expression level of p75NTR. This effect was selective for nerve growth factor (NGF). Taken together, the present study suggests that NGF contributes both to phenotypic regulation and to elimination of the dedifferentiated Schwann cells, while supporting survival or regeneration of certain types of axons during peripheral nerve repair or regeneration. GLIA 36:245–258, 2001.

Load Transmission Through the Wrist in the Extended Position

PURPOSE The wrist is subjected to extremely high compressive loads in the extended position, but pathoanatomy of this region remains unclear. The purpose of this study was to analyze force transmission in the maximum extended position to clarify the pathomechanics of wrist injury. METHODS Two sets of computed tomography images of wrist joints were obtained for 7 normal subjects: one set in neutral position and the other set in maximum extension. A three-dimensional rigid body spring model was used to analyze stress distributions through the wrist joint. The wrist joint was constructed from computed tomography images. External force was applied to the 5 metacarpals in neutral position and to the palm in extended position. Force transmissions through the carpus and ligament tension in extended position were compared with those in neutral position, and force distributions were compared in each position. RESULTS Force transmission ratio on the scaphoid fossa significantly increased from 52% in neutral to 62% in extension (p< .05), whereas the ratio through the lunate fossa decreased from 42% to 36%. In the midcarpal joint, force to the scaphoid significantly increased from 60% to 69% (p< .05). Force distributions of the radiocarpal joint in the extended position moved on the center of the lunate fossa and interfossal ridge of the scaphoid fossa. The dorsal ridge of the radial articular surface appeared as the new contact area. Tension in 3 palmar intrinsic ligaments and the flexor retinaculum greatly increased in the extended position. CONCLUSIONS Force transmission in the extended position shifted radially, concentrating at the scaphoid. We could show how bending force causes scaphoid fracture and concentration of force on the radius surface might cause intra-articular fracture coinciding with the fracture pattern introduced by Melone. The palmar intrinsic ligaments appear key to maintaining the carpal arch in push-up position. Our theoretical analysis could well explain several patterns of wrist injuries.

MMP-2 expression is associated with rapidly proliferative arteriosclerosis in the flexor tenosynovium and pain severity in carpal tunnel syndrome.

Due to the lack of correlation between symptom severity and electrophysiology or nerve function, the ‘container hypothesis’ has emerged as a new concept in carpal tunnel syndrome (CTS). This proposes that symptoms relate to connective tissue alteration rather than to nerve fibre pathology. This study was conducted to investigate the pathology of the flexor tenosynovium and its relationship with symptomatology. The subjects comprised 40 patients with electrophysiologically proven CTS who underwent open carpal tunnel release (age range: 31–79 years). In all patients, subjective symptom severity was assessed with a Likert scale and symptom duration was recorded preoperatively. Flexor tenosynovium biopsied during surgery was analysed for arterial and connective tissue alteration. Proliferative arteriosclerosis was graded using the modified Banff score. Gelatin zymography and immunohistochemistry were also performed to investigate the role of gelatinase in CTS. Relationships were evaluated using Spearman rank correlation coefficients. Proliferative arteriosclerosis occurred with disease progression in the flexor tenosynovium, in the absence of inflammation. This event did not correlate with patient age but correlated closely with symptom duration. Immunohistochemistry with antibodies against MMP‐2 and elastic van Gieson staining revealed that arterioles express high levels of MMP‐2 within 3 months of symptom onset and that intimal hyperplasia proceeded rapidly between 4 and 7 months, resulting in severe vascular narrowing. Gelatin zymography showed that MMP‐2 activity correlated negatively with symptom duration and positively with pain severity. Copyright

Clinical Significance of the Number of Positive Tumor Markers in Assisting the Diagnosis of Lung Cancer with Multiple Tumor Marker Assay

The clinical significance of multiple tumor marker assay in assisting the diagnosis of lung cancer was assessed in 67 patients with primary lung cancer, and 115 with nonmalignant pulmonary disease. The tumor markers studied were carbohydrate antigen 19-9 (CA19-9), carcinoembryonic antigen (CEA), neuron-specific enolase (NSE), squamous cell carcinoma-related antigen (SCC), and tissue polypeptide antigen (TPA). The positive rates for all of the tumor markers were significantly higher in the lung cancer group than in the nonmalignant pulmonary disease group. The sensitivity was 31-66%, the specificity was more than 90% for all five markers, and the accuracy was 69-82%. Among the markers, the positive rate of CEA was best correlated with adenocarcinoma (Ad), NSE with small cell carcinoma (Sm), SCC with squamous cell carcinoma (Sq), CA19-9 with Ad, and TPA with Ad. In multiple tumor marker assay, as the number of combined markers was increased, the sensitivity of the assay became higher and the specificity became lower, resulting in a lower accuracy. However, when more than two markers were positive, the relative possibility of lung cancer was increased 90-100%. The number of positive tumor markers in multiple tumor marker assay indicated that it would be of auxiliary value for the diagnosis of lung cancer.

Injuries in elite motorcycle racing in Japan

Objectives: To investigate the incidence and pattern of injuries, relative risks, and factors affecting incidence among elite motorcycle competitors in Japan. Methods: A total of 117 elite motorcycle competitors including 36 road racers, 60 motocross racers, and 21 trial bike riders completed a questionnaire about injuries. Results: Sixty major injuries (25 in road racing, 32 in motocross, and three in trial bike riding) were reported. The most common injuries were fractures (45), followed by ligament injuries (8), dislocations (5), and soft tissue injuries (2). The overall injury rate was 22.4 per 1000 hours, and the death rate was zero. There was no significant correlation between risk of injury and age, experience, or accumulated competition points. Conclusions: Injury rates in competitions such as road racing and motocross are high, and therefore additional safety measures are needed to protect competitors from injury.

Regenerating Axons Emerge Far Proximal to the Coaptation Site in End-to-side Nerve Coaptation without a Perineurial Window Using a T-shaped Chamber

Background: Considerable controversy exists concerning the mechanism of axonal regeneration in end-to-side neurorrhaphy. The authors studied the mode of axonal regeneration in end-to-side neurorrhaphy without a perineurial window using a rat sciatic nerve model. Methods: Twenty-seven rats were used. A 10-mm segment of peroneal nerve was harvested and coapted to the ipsilateral tibial nerve in end-to-side fashion using a T-shaped silicone chamber to minimize the tibial nerve damaged by surgery. To explain the role of nerve damage on axonal regeneration in end-to-side neurorrhaphy, we also used an isogenic nerve transplantation model in which the peroneal nerve remained intact. The mode of axonal regeneration was studied with electron microscopy, morphometric analysis, immunofluorescence, and immunohistochemistry. Results: Both morphometric analysis and immunolabeling of neurofilaments demonstrated that regenerating axons emerge at sites far proximal to the coaptation site, travel within the tibial nerve, traverse the perineurium circumferentially around the coaptation site, and then invade into the peroneal nerve. Electron microscopy and a double-labeled immunofluorescence study with antibodies against neurofilament and tenascin-C confirmed large-scale axonal penetration into the perineurium around the coaptation site. Immunofluorescence with antibody against NG2, a marker of axonal regeneration, prevented the possibility of collateral sprouting at the coaptation site. In addition, an end-to-side neurorrhaphy model with an isogenic peroneal nerve clearly demonstrated that nerve damage is a prerequisite for axonal regeneration through end-to-side neurorrhaphy. Conclusions: The authors could not locate the site of axonal sprouting in end-to-side neurorrhaphy without a perineurial window; however, this study cast doubts on current hypothesis on the mode of axonal regeneration in end-to-side neurorrhaphy.

Recovery process of sciatic nerve defect with novel bioabsorbable collagen tubes packed with collagen filaments in dogs.

Autologous nerve graft is the most commonly applied treatment for the patients with peripheral nerve defect, while application is limited because of tissue availability and unfavorable donor site morbidity. To overcome this problem, peripheral nerve regeneration using a nerve conduit has been studied. Especially, nerve conduit using biodegradable materials has been considered promising. In this study, a potential of collagen nerve conduit has been studied with special reference to the regenerating process of a peripheral nerve. Twelve adult female Beagle dogs weighting 10-12 kg were used. The peroneal nerve was cut to make a 30-mm defect. The nerve defect was bridged by the collagen artificial nerve conduit. Comprehensive functional, electrophysiological, morphometrical, and histological analyses were performed until one year after operation. The wet weight of tibialis anterior muscles was only 32.4% of the healthy side at 24 weeks, which was recovered to 77.4% at 52 weeks after denervation. Electrophysiological evaluation of tibialis anterior muscle belly showed polyphasic wave at 52 weeks after implantation, which was almost half amplitude as compared with that of control. The diameters of myelinated nerve fibers thickened day by day, and the average diameter was 5.16 microm at PFN, 3.91 microm at CG, and 3.75 microm at DFN, and average thickness of myelin sheath was 0.94 microm at PFN, 0.46 microm at CG, and 0.55 microm at DFN after 52 weeks. The distribution of myelinated nerve fiber size in the 52 weeks group was distinctly bimodal with the major peak at approximately 2-4 microm and the minor peak at 10-12 microm. These findings were consistent with the distribution of the normal nerve fiber. This study proves the feasibility of the collagen artificial nerve conduit for promoting nerve regeneration, raises new possibilities of seeking alternatives to autograft for nerve repair. The results from this study showed detailed process of morphological, electrophysiological, and functional recovery of the regenerated nerve, which would provide scientific background for this novel therapy.

Preservation of the knee joint in limb salvage of osteosarcoma in the proximal tibia. A case report.

Summary.A 12-year-old boy with osteosarcoma in the proximal tibia underwent a successful limb-saving operation with preservation of the epiphyseal and articular cartilage of the proximal tibia as a result of his remarkable response to chemotherapy. There was no evidence of tumour invasion to the adjacent physis, as demonstrated by image findings. The bone defect was reconstructed using autoclaved autogeneous bone with a vascularized fibula. The patient exhibits excellent function of the affected limb, and the knee joint remains disease-free 55 months postoperatively.Résumé.Un ostéosarcome du tibia proximal a été traité avec succès chez un garçon de 12 ans, en préservant le cartilage de croissance et le cartilage articulaire grâce à une bonne réponse à la chimiothérapie. Il n’y avait pas d’invasion de l’épiphyse. Le défect osseux a été reconstruit en utilisant le tibia après autoclavage associéà un péroné vascularisé. 55 mois après l’opération, le patient est indemne de maladie tumorale et a une excellente fonction de son membre inférieur.