Rikuo Shinomiya

Transplantation of Meniscus Regenerated by Tissue Engineering With a Scaffold Derived From a Rat Meniscus and Mesenchymal Stromal Cells Derived From Rat Bone Marrow

The purpose of this study was to assess transplantation of regenerated menisci using scaffolds from normal allogeneic menisci and bone-marrow-derived mesenchymal stromal cells (BM-MSCs) of rats. We reported that scaffolds derived from normal menisci seeded with BM-MSCs in vitro could form meniscal tissues within 4 weeks. Then, we hypothesized that our tissues could be more beneficial than allogeneic menisci regarding early maturation and chondroprotective effect. Bone marrow was aspirated from enhanced green fluorescent protein transgenic rats. BM-MSCs were isolated and seeded onto scaffolds which were prepared from Sprague-Dawley rat menisci. After 4 weeks in coculture, the tissues were transplanted to the defect of menisci. Repopulation of BM-MSCs and expression of extracellular matrices were observed in the transplanted tissues at 4 weeks after surgery. At 8 weeks, articular cartilage in the cell-free group was more damaged compared to that in the cell-seeded group or the meniscectomy group.

Human platelet-rich plasma promotes axon growth in brain-spinal cord coculture

Platelet-rich plasma (PRP) contains several growth factors, including platelet-derived growth factor (PDGF), transforming growth factor-&bgr;1 (TGF-&bgr;1), insulin-like growth factor-1 (IGF-1), and vascular endothelial growth factor (VEGF), that are associated with repair processes after central nervous system injury. Although PRP have been applied to some regenerative therapies, the regeneration effects of PRP on spinal cord injury have not been reported. This study applied a rat organ coculture system to examine the ability of PRP to enhance axonal growth in spinal cord tissues and to identify the growth factors in PRP that contribute to the regulation of axon growth. PRP from human peripheral blood was added to organ cocultures. Furthermore, neutralizing antibodies against PDGF-AB, TGF-&bgr;1, IGF-1, or VEGF were added to the cocultures with PRP. Axon growth from the brain cortex into the spinal cord was assessed quantitatively using anterograde axon tracing with DiI. Addition of PRP to the cocultures promoted axon growth, and the axon growth was significantly suppressed by the addition of neutralizing antibodies against IGF-1 and VEGF, but not PDGF-AB. In contrast, axon growth was promoted significantly by the addition of neutralizing antibodies against TGF-&bgr;1. These findings indicate that PRP promotes axon growth in spinal cord tissues through mechanisms associated with IGF-1 and VEGF, and that TGF-&bgr;1 in PRP exerts negative effects on axon growth.

HIGH-RESOLUTION ULTRASONOGRAPHIC EVALUATION OF ''HOURGLASS-LIKE FASCICULAR CONSTRICTION'' IN PERIPHERAL NERVES: A PRELIMINARY REPORT

An hourglass-like constriction is a focal fascicular lesion observed in one or a few places in one or a few fascicles of a peripheral nerve trunk, and usually affects the anterior interosseous (AIN) or posterior interosseous (PIN) nerve. Constrictions have previously been discovered only by surgical exploration, and have been unable to be recognized on pre-operative imaging. We encountered some cases in which the lesion was able to be diagnosed pre-operatively by high-resolution ultrasonography; these findings were then confirmed intra-operatively. Five consecutive cases were included in this study. In three cases with constrictions revealed on pre-operative ultrasound, the findings were confirmed intra-operatively. In the remaining two cases in which no constrictions were detected pre-operatively, no constriction was revealed intra-operatively. High-resolution ultrasonography may play a significant role in the diagnosis of hourglass-like constrictions, and may thus lead to significant changes in treatment strategies for AIN and PIN palsy.

The cellular origin of cartilage-like tissue after periosteal transplantation of full-thickness articular cartilage defects: An experimental study using transgenic rats expressing green fluorescent protein

Background Periosteal transplantation is commonly used for the treatment of articular cartilage defects. However, the cellular origin of the regenerated tissue after periosteal transplantation has not been well defined. The objective of this study was to investigate the cellular origin of the regenerated tissue after periosteal transplantation. Method Free periosteum was harvested from the tibia of 10-week-old adolescent enhanced green fluorescent protein (GFP-) expressing transgenic Sprague Dawley (SD) rats and was transplanted to full-thickness articular cartilage defects of the patellar groove in normal 10-week-old adolescent SD rats. The periosteum was sutured to the defect with the cambium layer facing the joint cavity. 8 SD rats were killed at 4 weeks and 8 SD rats were killed at 8 weeks after surgery. The repaired tissue was assessed histologically and histochemically. GFP-positive cells derived from the donor periosteum could easily be detected in the repaired tissue by use of a fluorescent microscope. Results At both 4 and 8 weeks after transplantation, the entire area of the defects had been repaired, with the regenerated tissue being well stained histologically with safranin-O. Most cells in the whole area of the regenerated tissue were GFP-positive, indicating that very few of the cells were GFP-negative cells originating from the recipient rats. Interpretation This experiment demonstrates that most cells in regenerated tissue after periosteal transplantation using adolescent animals do not originate from recipient cells but from the periosteal cells of the donor.   ▪

Use of quantitative intra-operative electrodiagnosis during partial ulnar nerve transfer to restore elbow flexion: THE TREATMENT OF EIGHT PATIENTS FOLLOWING A BRACHIAL PLEXUS INJURY

The transfer of part of the ulnar nerve to the musculocutaneous nerve, first described by Oberlin, can restore flexion of the elbow following brachial plexus injury. In this study we evaluated the additional benefits and effectiveness of quantitative electrodiagnosis to select a donor fascicle. Eight patients who had undergone transfer of a simple fascicle of the ulnar nerve to the motor branch of the musculocutaneous nerve were evaluated. In two early patients electrodiagnosis had not been used. In the remaining six patients, however, all fascicles of the ulnar nerve were separated and electrodiagnosis was performed after stimulation with a commercially available electromyographic system. In these procedures, recording electrodes were placed in flexor carpi ulnaris and the first dorsal interosseous. A single fascicle in the flexor carpi ulnaris in which a high amplitude had been recorded was selected as a donor and transferred to the musculocutaneous nerve. In the two patients who had not undergone electrodiagnosis, the recovery of biceps proved insufficient for normal use. Conversely, in the six patients in whom quantitative electrodiagnosis was used, elbow flexion recovered to an M4 level. Quantitative intra-operative electrodiagnosis is an effective method of selecting a favourable donor fascicle during the Oberlin procedure. Moreover, fascicles showing a high-amplitude in reading flexor carpi ulnaris are donor nerves that can restore normal elbow flexion without intrinsic loss.

Comparative study on the effectiveness of corticosteroid injections between trigger fingers with and without proximal interphalangeal joint flexion contracture

Trigger fingers with proximal interphalangeal joint flexion contracture are suggested to have a poorer response to corticosteroid injection than those without contracture, though this has not been proven scientifically. We compared the clinical response to corticosteroid injection between trigger fingers with and without proximal interphalangeal joint contracture, and investigated the influence of the injection on the A1 pulley and flexor digitorum tendons using ultrasonography. One month after injection, pain was significantly reduced in the no contracture group, and 56% of trigger fingers with proximal interphalangeal joint contracture resolved. Before injection, relative thickening of the A1 pulley and flexor digitorum tendons, and a partial hypoechoic lesion of the flexor digitorum superficialis tendon were observed in the contracture group. One month after injection, the thickening of the tendons and the A1 pulley was reduced, but the partial hypoechoic lesion was still observed in significant numbers. We have demonstrated that the presence of a proximal interphalangeal joint contracture was associated with a reduced clinical response to corticosteroid injection, and we suggest that the pathologic change in the flexor digitorum superficialis tendon, represented by the partial hypoechoic lesion, contributed to corticosteroid injection resistance. Level of evidence: IV

Bone peg fixation for the treatment of nonunion of the shaft of the distal phalanx.

ulnar nerve territory. We feel that this complication was related to the initial wrist operation rather than the fracture because after the fracture but before the surgery, the patient reported only mild dysaesthesia in her entire hand. It was not until after surgery that she specifically complained of median nerve symptoms, making it more likely that something had occurred intraoperatively. Moreover, median nerve complications from distal radius fractures have all been reported to occur at the carpal tunnel, but this was not the case in our patient. The fibrosis could be due to the surgical approach or the plate itself. We feel that it was the former because the nerve was scarred along the entire length of the surgical incision. The skin incision itself may have been placed slightly more ulnar than usual, putting the median nerve at risk during the surgical exposure. It is also possible that an error in the position or prolonged use of a self-retaining retractor could have lead to the scarring. Our case demonstrates that scarring around the median nerve, proximal to the carpal canal, can occur after the palmar approach to the distal radius, leading to progressive median nerve palsy. Median nerve symptoms after palmar plating may not be caused by compression within the carpal tunnel and if fibrosis is present a neurolysis could help.

Correlation between “hourglass‐like fascicular constriction” and idiopathic anterior interosseous nerve palsy

Introduction: In recent operative cases of anterior interosseous nerve palsy (AINP), hourglass‐like fascicular constrictions have been reported. We prospectively investigated the ultrasonographic history of these lesions to better understand the role of this lesion in AINP. Methods: Seven patients who were diagnosed with idiopathic AINP based on classic clinical findings and had hourglass‐like fascicular constrictions found on ultrasonography were included. All but 1 patient selected surgery, and we followed up all patients clinically and with ultrasonography. Results: In the 5 patients treated surgically in whom paralysis recovered to a level greater than M4, postoperative ultrasonography revealed less constriction. The other patient experienced little recovery after surgery, and the severe constriction remained. In a conservatively treated patient, the paralysis recovered completely, and upon ultrasonography, the constriction had lessened. Conclusions: Although the mechanism is still unknown, hourglass‐like fascicular constriction lessened with relief of motor weakness both in operatively and conservatively treated patients. Muscle Nerve 55: 508–512, 2017

Slow progressive popliteal artery insufficiency after neglected proximal tibial physeal fracture: a case report.

Popliteal artery injury is most commonly associated with high-energy trauma, which is easily diagnosed upon initial physical examination. However, in some situations, the diagnosis of arterial injury is delayed because of slow progression of arterial insufficiency, which may lead to limb amputation. We report a rare case of popliteal arterial occlusion with the presence of arterial pulses during initial assessment, resulting from a neglected proximal ibial physis fracture. This case shows that even in the presence of foot pulses, the surgeon must consider the possibility of a popliteal artery damage whenever trauma is seen near the knee joint.

Spontaneous recovery of a case with suspected hourglass-like fascicular constriction and anterior interosseous nerve palsy.

en neurofibroma by Lazarus and Trombetta in 1978. The aetiology and natural history of this nerve tumour remains unclear. Previous studies suggested that a perineurioma might be a reaction to compression or trauma. However, other studies suggest a neoplastic disease since a chromosomal 22 deletion was identified (Emory et al., 1995). Intraneural perineurioma usually presents as a painless mononeuropathy with progressive motor weakness. Sensory involvement is uncommon. Intraneural perineurioma is most prevalent in young adults and the upper extremities are affected most commonly (Cortes et al., 2005). However, there is only one case reported involving a digital nerve (Emory et al., 1995). Although magnetic resonance imaging is a valuable method in identifying soft tissue tumours and nerve sheath tumours, there is a lack of specificity. Magnetic resonance imaging findings of intraneural perineuriomas are nonspecific. Biopsy is necessary to establish a definitive diagnosis. The treatment of intraneural perineurioma remains controversial: a conservative approach is usually justified as these tumours are benign and slowly progressive, however surgery is recommended in patients with neurological or functional deficits. Resection with graft repair, intraneural neurolysis and nerve transfers have been described. Since there is a large variety in presentation and localization, each case needs to be discussed individually. In conclusion, an intraneural perineurioma is a benign peripheral nerve sheath tumour with an unknown natural history that is very rare in a digit. The type of treatment depends on clinical presentation and localization of the tumour. The radial digital nerve of the index finger has an important sensory function in pinch and tripod grip, which ideally should be preserved. However, in our opinion, resecting the entire digital nerve was the best treatment to solve the functional problems of the digit in this case. Conflict of interests