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Background: Acute dislocation of the thumb carpometacarpal (CMC) joint is a rare and challenging injury, and its treatment remains controversial. The purpose of the study was to evaluate the clinical outcome after surgical repair of the dorsal capsulo-ligamentous complex. Materials and methods: Eight patients with a mean age of 39.8 years (range, 23 - 56 years) treated for the thumb CMC joint were treated in our hospital between 2008 and 2018. The ruptured dorsal capsulo-ligamentous complex was repaired using suture anchors in all patients, and the joint was immobilized with a Kirschner wire pinning and splint for 3 weeks. The clinical outcome was assessed by measuring the range of motion of the thumb CMC joint and the Japanese Society for Surgery of the Hand version of the Quick Disability of the Arm, Shoulder, and Hand (Q-DASH-JSSH) score. Results: The mean radial abduction of the thumb CMC joint was 66°, and the volar abduction was 63°. The mean Q-DASH-JSSH score was 4.8 (range, 0 - 15.6). There were no cases of infection, nerve disturbance, or osteoarthritis. Anatomical reduction was observed in seven patients at the final follow-up and in a rugby football player at 6 months of follow-up; however, subluxation of the thumb CMC joint at 12 months of follow-up due to reinjury was observed. Conclusion: Surgical repair of the dorsal capsulo-ligamentous complex with suture anchors is a reliable and simple treatment for acute unstable dislocation of the thumb CMC joint.

Electrophysiological examination is important for the diagnosis and evaluation of nerve function in carpal tunnel syndrome (CTS). Electrophysiological severity classifications of CTS using a nerve conduction study (NCS) have been reported, and there are many reports on the relationship between severity classifications and clinical symptoms. The existing electrophysiological severity classifications have several problems, such as cases that do not fit into a classification and unclear reasons for the boundary value. The purpose of this study was to clarify the relationship between sensory nerve conduction velocity (SCV) and distal motor latency (DML) and to evaluate whether the existing severity classification method is appropriate. We created a scatter diagram between SCV and DML for our NCSs and found a negative correlation between SCV and DML (correlation coefficient, −0.786). When we applied our NCSs to the existing classifications (Padua and Bland classifications), there were many unclassifiable cases (15.2%; Padua classification), and the number of Grade 3 cases was significantly higher than that of Grade 2 or 4 cases (Bland classification). Our large dataset revealed a strong negative correlation between SCV and DML, indicating that the existing severity classifications do not always accurately reflect the severity of the disease.

The authors previously reported a CT-based nonlinear finite element analysis (nonlinear CT/FEA) model to investigate loading stress distribution in the femoral shaft of patients with atypical femoral fractures (AFFs). This showed that stress distribution, influenced primarily by femoral bowing, may determine the location of AFF. Here, we demonstrate the locational characteristics associated with AFFs in an Asian, specifically Japanese, population regarding bone strength. This is the second report from our multicentre research project suggesting a possible new concept of diagnostic criteria or treatment according to AFF subtype.A multicentre prospective study was conducted at 12 hospitals in Japan from August 2015 through June 2018. We recruited three study groups composed of elderly females over the age of 60 years-the mid-shaft AFF group (n = 14; 80.0 ± 6.5 years), the subtrochanteric AFF group (n = 15; 73.9 ± 6.8 years), and the control group who had sustained unilateral hip fracture (n = 21; 82.1 ± 7.1 years)-and analysed femoral neck bone density and strength. Bone strength of the femoral neck was predicted with an evaluation method using nonlinear CT/FEA in both standing and falling configuration.Femoral neck bone density and strength were significantly higher in the subtrochanteric AFF group compared with the mid-shaft AFF and control groups (p 0.0001). No significant difference was seen in bone strength between the mid-shaft AFF and control groups (standing, p = 0.7616; falling, p = 0.3803).AFF has different features, in terms of bone strength, depending on fracture location. At the very least, Japanese patients with mid-shaft AFF could be at high risk of hip fracture because of bone fragility, in contrast to the firm bone of subtrochanteric AFF. For internal fixation of mid-shaft AFF using an IM nail, cervical screw insertion toward the femoral head might be recommended to prevent possible hip fracture.

We have investigated mid-shaft stress fractures of the bowed femoral shaft (SBFs), well before the first report of an association between suppression of bone turnover and atypical femoral fractures (AFFs). Although all cases of SBF meet the criteria for AFF, SBFs can also occur in patients with no exposure to bone turnover suppression-related drugs (e.g., bisphosphonates). Using bone morphometry and biomechanical analyses, we devised a theory of AFF subtypes, dividing AFFs into fragility SBFs in the mid-shaft and "typical" subtrochanteric AFFs caused by suppressed bone turnover. The aim of this multicenter prospective study was to provide evidence for this novel concept in terms of biological activity.The study was conducted at 12 hospitals in Japan from 2015 through 2019. Thirty-seven elderly women with AFF were included and classified according to location of the fracture into a mid-shaft AFF group (n = 18) and a subtrochanteric AFF group (n = 19). Patient demographics and clinical characteristics were investigated to compare the two groups. The main focus was on histological analysis of the fracture site, and bone metabolism markers were evaluated to specifically estimate biological activity.All patients in the subtrochanteric AFF group had a history of long-term (3 years) exposure to specific drugs that have been reported to cause AFF, but 5 of the 18 patients in the mid-shaft AFF group had no history of exposure to such drugs. Femoral bowing was significantly greater in the mid-shaft AFF group (p 0.001). In the histological analysis, active bone remodeling or endochondral ossification was observed in the mid-shaft AFF group, whereas no fracture repair-related biological activity was observed in the majority of patients in the subtrochanteric AFF group. Levels of tartrate-resistant acid phosphatase-5b and undercaroxylated osteocalcin were significantly lower in the subtrochanteric AFF group (p 0.05).The possibility of our devised AFF subtype theory was demonstrated. Biological activity tends not to be suppressed in mid-shaft SBFs unlike in "typical" subtrochanteric AFFs involving bone turnover suppression. Although validation of the proposed theory in other populations is needed, we suggest that the pathology and treatment of AFFs be reconsidered based on its subtype.

Schwann cell proliferation in peripheral nerve injury (PNI) enhances axonal regeneration compared to central nerve injury. However, even in PNI, long-term nerve damage without repair induces degeneration of neuromuscular junctions (NMJs), and muscle atrophy results in irreversible dysfunction. The peripheral regeneration of motor axons depends on the duration of skeletal muscle denervation. To overcome this difficulty in nerve regeneration, detailed mechanisms should be determined for not only Schwann cells but also NMJ degeneration after PNI and regeneration after nerve repair. Here, we examined motor axon denervation in the tibialis anterior muscle after peroneal nerve transection in thy1-YFP mice and regeneration with nerve reconstruction using allografts. The number of NMJs in the tibialis anterior muscle was maintained up to 4 weeks and then decreased at 6 weeks after injury. In contrast, the number of Schwann cells showed a stepwise decline and then reached a plateau at 6 weeks after injury. For regeneration, we reconstructed the degenerated nerve with an allograft at 4 and 6 weeks after injury, and evaluated functional and histological outcomes for 10 to 12 weeks after grafting. A higher number of pretzel-shaped NMJs in the tibialis anterior muscle and better functional recovery were observed in mice with a 4-week delay in surgery than in those with a 6-week delay. Nerve repair within 4 weeks after PNI is necessary for successful recovery in mice. Prevention of synaptic acetylcholine receptor degeneration may play a key role in peripheral nerve regeneration. All animal experiments were approved by the Institutional Animal Care and Use Committee of Tokyo Medical and Dental University on 5 July 2017, 30 March 2018, and 15 May 2019 (A2017-311C, A2018-297A, and A2019-248A), respectively.

Summary In this case-control study, we concluded that women with distal radial fractures who were surgically treated showed lower grip strength and dynamic body balancing than those of controls. These results suggest that measurements of grip strength and dynamic body balance may be useful screening tools to assess future fracture risk. Introduction Patients with distal radial fractures (DRFs) are at risk of future fragility fractures. However, their physical characteristics and tendencies for falls remain unclear. We aimed to compare the physical characteristics of women with and without distal radial fractures. Methods We included 128 women with a DRF as their first fragility fracture (fracture group) who underwent surgical treatment. Concurrently, 128 age- and sex-matched participants without a history of fragility fractures were selected as controls (control group). The participants underwent assessments of grip strength and the body balancing ability test. Measurements were taken twice in the fracture group, at 2 weeks and 6 months postoperatively, and once in the control group. The body balancing ability test included the Functional Reach Test, Timed Up and Go test (TUG), 2-Step test (2ST), and Timed Uni-pedal Stance test. The participants also completed questionnaires about their health. Results There were no significant differences (p > 0.05) in patient characteristics between the groups. The fracture group showed lower grip strength across all age groups. In the DRF group, prolonged TUG time was observed at 2 weeks postoperatively in all age groups and at 6 months in participants aged 55–74 years; the 2ST score was significantly lower in participants aged between 65 and 74 years. Conclusions Women with DRF demonstrated lower grip strength and dynamic body balancing ability. Lower grip strength and dynamic body balancing ability were identified as significant risk factors in women with DRF, suggesting that these may be useful screening tools to assess fracture risk. Electronic supplementary material The online version of this article (10.1007/s00198-018-04816-4) contains supplementary material, which is available to authorized users.

Background Various pathological elbow lesions are often complicated with ulnar neuropathy at the elbow (UNE), although the precise pathology, incidence, and clinical and neurological features of these lesions have not been identified. We therefore investigated elbow pathology and neurological severity in Japanese patients with UNE. Methods The medical records of 457 Japanese UNE patients who were surgically treated among 6 hospitals were retrospectively examined. Eligible patients had UNE diagnosed by physical findings and nerve conduction studies according to the criteria of the American Association of Electrodiagnostic Medicine. The elbows were analyzed with regard to age, gender, occupation, pathology at the elbow, and severity of nerve palsy. Results A total of 398 patients with 413 UNE elbows of a mean age of 63 years (range: 15–87) met the inclusion criteria. UNE elbows were predominantly in male patients (69.0%). Overall, 310 elbows (75.1%) had 1 or more elbow lesions: 238 elbows (76.8%) had a single lesion and 72 elbows (23.3%) had 2 or more lesions. The most common lesion was primary elbow osteoarthritis (EOA) occurring in 54.5% of elbows, followed next by medial elbow ganglion in 8.5% and cubitus valgus in 6.5%. Most elbows with medial elbow ganglion or cubitus valgus were associated with EOA. Entrapment sites were at the cubital tunnel in 84.5%–91.3% of UNE elbows, regardless of an association with elbow lesion. The incidence of McGowan grade III lesion was 50.8% in elbows with primary EOA, which was higher than the 35.0% in elbows with no lesion. Conclusions This study revealed that UNE had various isolated or combined elbow lesions. In Japanese UNE, primary or secondary EOA was found in 62.2% of cases and severe motor weakness was noted in 47.2%. The incidences of EOA and severe ulnar nerve palsy in the Japanese UNE are higher than those in Caucasians. Level of evidence Level IV; Prognostic—Investigating the effect of a patient characteristic on the outcome of a disease; Case series.

Case We report a rare case of complete rupture of the right femoral nerve at the pelvic level, which was caused by a self-inflicted stab wound. The nerve was surgically reconstructed with use of an autologous sural nerve cable graft. Postoperatively, the patient's sensorimotor function returned to near normal. Conclusion Femoral nerve rupture caused by a laceration is very unusual. A bilateral sural nerve cable graft performed in collaboration with surgeons from other specialties achieved a good outcome in this otherwise healthy young patient.

Loading stress due to individual variations in femoral morphology is thought to be strongly associated with the pathogenesis of atypical femoral fracture (AFF). In Japan, studies on AFF regarding pathogenesis in the mid-shaft are well-documented and a key factor in the injury is thought to be femoral shaft bowing deformity. Thus, we developed a CT-based finite element analysis (CT/FEA) model to assess distribution of loading stress in the femoral shaft.A multicenter prospective study was performed at 12 hospitals in Japan from August 2015 to February 2017. We assembled three study groups-the mid-shaft AFF group (n=12), the subtrochanteric AFF group (n=10), and the control group (n=11)-and analyzed femoral morphology and loading stress in the femoral shaft by nonlinear CT/FEA.Femoral bowing in the mid-shaft AFF group was significantly greater (lateral bowing, p0.0001; anterior bowing, p0.01). Femoral neck-shaft angle in the subtrochanteric AFF group was significantly smaller (p0.001). On CT/FEA, both the mid-shaft and subtrochanteric AFF group showed maximum tensile stress located adjacent to the fracture site. Quantitatively, there was a correlation between femoral bowing and the ratio of tensile stress, which was calculated between the mid-shaft and subtrochanteric region (lateral bowing, r=0.6373, p0.0001; anterior bowing, r=-0.5825, p0.001).CT/FEA demonstrated that tensile stress by loading stress can cause AFF. The location of AFF injury could be determined by individual stress distribution influenced by femoral bowing and neck-shaft angle.

Introduction Stress fractures of the bowed femoral shaft (SBFs) may be one of the causes of atypical femoral fractures (AFFs). The CT-based finite element method (CT/FEM) can be used to structurally evaluate bone morphology and bone density based on patient DICOM data, thereby quantitatively and macroscopically assessing bone strength. Here, we clarify the pathogenic mechanism of SBFs and demonstrate this new understanding of AFFs through mechanical analysis by CT/FEM. Patients and methods A prospective clinical study was performed from April 2012 to February 2014. We assembled two study groups, the bowed AFF group ( n =4 patients; mean age, 78.0 years) including those with a prior history of AFF associated with bowing deformity and the thigh pain group ( n =14 patients; mean age, 78.6 years) comprising outpatients with complaints of thigh pain and tenderness. Stress concentration in the femoral shaft was analysed by CT/FEM, and the visual findings and extracted data were assessed to determine the maximum principal stress (MPS) and tensile stress–strength ratio (TSSR). In addition, we assessed femoral bowing, bone density, and bone metabolic markers. Wilcoxon's rank sum test was used for statistical analysis. Results All patients in the bowed AFF group showed a marked concentration of diffuse stress on the anterolateral surface. Thirteen patients in the thigh pain group had no significant findings. However, the remaining 1 patient had a finding similar to that observed in the bowed AFF group, with radiographic evidence of bowing deformity and a focally thickened lateral cortex. Patients were reclassified as having SBF ( n =5) or non-SBF ( n =13). Statistical analysis revealed significant differences in MPS ( p =0.0031), TSSR ( p =0.0022), and femoral bowing (lateral, p =0.0015; anterior, p =0.0022) between the SBF and non-SBF groups, with no significant differences in bone density or bone metabolic markers. Conclusions Significant tensile stress due to bowing deformity can induce AFFs. SBFs should be considered a novel subtype of AFF, and patients with complaints of thigh pain and femoral shaft bowing deformity must be considered at high risk for AFFs. This project (Ref: AOTAP 13-13) was supported by AOTrauma Asia Pacific.

We have studied stress fractures of the bowed femoral shaft (SBFs) among elderly Japanese for over a decade. On the other hand, severely suppressed bone turnover (SSBT) after long-term bisphosphonates (BPs) use has been considered to be one of the causes of low-energy diaphyseal femoral fractures, often called atypical femoral fractures (AFFs). Some studies have shown that BPs use for more than 5 years is associated with an increased risk of AFFs. Here, we present a report of our SBF case series experienced in the past 15 years in order to examine whether bowing deformity should be considered among the causes of AFFs.Subjects were 13 Japanese female patients with low-energy femoral shaft fractures. Mean age at injury was 77.0 years (range 67-88 years). All patients met the criteria of the AFFs' case definition. The first author treated 11 of the 13 patients over 8 years (2005-2012) based on the concept of SBFs. Regarding the regional characteristics of these patients, 10 were treated at 2 rural hospitals, and 3 were treated at 3 urban hospitals. Retrospectively, we assessed fracture type and location, existence of fracture on the contralateral side, bowing deformity, and duration of BPs use.All 13 cases were AO/OTA type 32-A. Incomplete or previous fracture on the contralateral side was noted in 10 cases. Obvious bowing deformity of the femoral shaft was noted in 12 cases. BPs were taken in 7 cases, only 3 of which involved BPs use for more than 5 years.We experienced 12 cases of low-energy femoral shaft fractures associated with bowing deformity. Six cases were not treated with BPs at all. Stress fractures associated with a femoral shaft bowing deformity do actually exist and should be recognized as another cause of AFFs.

Purpose To identify the unique anatomical characteristic of the extensor carpi radialis brevis (ECRB) origin and points of differentiation from other extensors and to clarify the specific relationship of the ECRB to the underlying structures. Methods We studied the origin of each extensor macroscopically for its muscular and tendinous parts; to identify the relationship between the ECRB origin and the deeper structures, we also examined the attachment of the joint capsule under the ECRB origin. Results The ECRB simply originated as a tendon without any muscle, whereas other extensors originated as a mixture of tendon and muscle. At the anterior part of the ECRB origin, the thin attachment of the joint capsule (average width, 3.3 mm) lay deep to the ECRB and was distinct. However, at the posterodistal portion, the joint capsule, annular ligament, and supinator were intermingled and originated as a single wide sheet from the humerus (average width, 10.7 mm). Conclusions The anterior part of the ECRB origin was delicate, because the ECRB origin was purely tendinous, and the attachment of the articular capsule was thin compared with that of the posterodistal attachment. This thin attachment could be an initial factor leading to the development of lateral epicondylitis. Clinical relevance The results of the current study may enhance magnetic resonance imaging understanding and may help clarify the etiology of the lateral epicondylitis.

The article Lower grip strength and dynamic body balance in women with distal radial fractures, written by. K. Fujita, H. Kaburagi, A. Nimura, T. Miyamoto, Y. Wakabayashi, Y. Seki, H. Aoyama, H. Shimura, R. Kato, A. Okawa was originally published electronically on the publisher's internet portal.

Flap necrosis remains a major complication of reconstructive surgery. To improve skin flap survival, various treatments with vasodilators, antiplatelet drugs, or the local administration of growth factors have been performed. However, the sufficient prevention of skin necrosis is not well established. Platelet-rich plasma has been used as an autologous factor and includes various growth factors. The authors evaluated whether or not platelet-rich plasma can improve skin flap survival in an experimental rat model.Cranially based dorsal cutaneous flaps were elevated in 48 rats. The animals received subcutaneous injections of either platelet-rich plasma (100 μl) or platelet-poor plasma (100 μl). The rats were divided into three groups: the platelet-rich plasma group (n = 16), the platelet-poor plasma group (n = 16), and the nontreatment group (n = 16). Flap survival was measured and histologic specimens were collected on day 7. Real-time polymerase chain reaction specimens were collected after 8 hours, 24 hours, 3 days, and 7 days.Platelet-rich plasma significantly improved flap survival rates (61.2 percent) compared with the platelet-poor plasma treatment (35.8 percent) and nontreatment groups (28.0 percent). A histologic analysis showed that significantly fewer inflammatory cells and an increased blood vessel density were observed in the platelet-rich plasma rats versus the platelet-poor plasma or nontreatment rats. In addition, platelet-rich plasma treatment significantly increased the mRNA levels of vascular endothelial growth factor and platelet-derived growth factor.Platelet-rich plasma modulates the genes involved in angiogenesis and improves skin flap survival.

It is known that Rho family small GTPases activate a number of signal transduction pathways involved in cell cycle progression, gene expression, and cell survival. These small G proteins play an important role in neuronal survival and axon regeneration in neural injury. In this study, we tested whether the activity of RhoA or Rac1 regulates neurite extension in dorsal root ganglia (DRGs) in vitro and nerve regeneration in injured sciatic nerves. Regeneration of neurites from explanted DRGs was accelerated by combined suppression of RhoA and Rac1 activity using adenoviruses expressing dominant negative (DN) forms of both RhoA and Rac1 (Ad-Rho/RacDN) in vitro. Rat sciatic nerves were cut and Ad-Rho/RacDN was injected into the proximal stumps. After bridge grafting with chitosan mesh tubes, muscle evoked potentials induced by transcranial electrical stimulation were recorded eight weeks postoperatively. The terminal latencies were shorter in the Ad-Rho/RacDN group than in the control group. Histological analysis revealed extensive regrowth of neurofilament-positive and myelinated axons within the tubes in the group that received Ad-Rho/RacDN. These findings suggest that combined regulation of RhoA and Rac1 using DN adenoviral transgenic methods has the potential to modify injured peripheral nerve tissues directly.

Dear Sir, As treatments for the laxity of metacarpophalangeal (MCP) joint in hypoplastic thumb, joint capsular plication, free tendon graft or MCP arthrodesis have been performed [1]. In addition, transfer of abductor digiti minimi [2] or ring finger flexor digitorum superficialis [3] have been used to provide thumb opposition and restore MCP joint stability. In the present case, we used extensor digiti minimi (EDM) transfer to treat MCP joint instability due to ulnar collateral ligament laxity in a patient with thumb polydactyly without thenar muscle atrophy. An 11-year-old girl who was naturally right thumb polydactyly with floating ulnar thumb had a thumb plasty at the age of five. But she was bothered by an unstable MCP joint due to ulnar collateral hypoplasia (Fig. 1a). Six years later from primary operation, she underwent a second surgery to improve joint instability and outer appearance of the thumb. The MCP joint instability was corrected by an EDM transfer, which involved fasting the end of the transferred tendon to the ulnar side of the MCP joint at the bottom of proximal phalanx and at the metacarpal head (Fig. 2). At 10 months postoperatively, the appearance of the thumb was improved and the MCP joint was stable (Fig. 1b). The EDM transfer procedure was initially reported for restoration of thumb adduction in ulnar nerve paralysis [4], but MCP joint stability could be achieved by changing the distal tendon insertion as this case. We consider there are some advantages to this procedure: 1) the MCP joint achieves maximum stability in the opposite position, because the tension of the transferred EDM tendon increases with the increase in the angle of opposition, 2) the mobility of the MCP joint is not impaired, 3) the strength of side pinch could be increased by increasing the thumb adduction force. On the other hand, the disadvantages of this procedure include that this transfer would position thumb in extension and adduction, and a decrease in the extension force of the little finger. The former demerit barely mattered in actuality, because we think the tension of transferred EDM is not strong in the rest position.

STUDY DESIGN Expression patterns of fibroblast growth factor-2 (FGF-2) in distal transected spinal cord in infant and adult rats were determined by reverse-transcription polymerase chain reaction (RT-PCR) and immunostaining. OBJECTIVE To reveal the expression pattern of FGF-2 in distal transected cord of infant and adult rats. SUMMARY OF BACKGROUND DATA Descending fibers in the spinal cord of infant and adult rats show different regenerative capacity. One explanation is that different levels of FGF-2, an important neurotrophic factor for promoting neurite outgrowth and repair, are expressed in the distal transected cords of the rats, providing different levels of support for severed axons. MATERIALS AND METHODS Spinal cords of infant and adult rats were completely transected. At 12, 24, and 72 hours and at 1 week, segments of distal spinal cord tissues were removed and expression of FGF-2 mRNA was evaluated by RT-PCR. The distribution of FGF-2 and the phenotype of FGF-2-positive cells were determined by immunostaining. RESULTS Expression of FGF-2 mRNA was shown to be up-regulated in the distal cord of infant rats but not adult rats. Immunohistochemical analysis showed that neurons in distal cord of infant rats were rich in FGF-2 immunoreactivity (IR), whereas in adult rat neurons FGF-2 IR was hardly observed at all, although a few FGF-2-positive astrocytes were observed in the white matter. CONCLUSION After complete spinal cord transection, the expression of FGF-2 in the distal cord of infant rats was high compared with that of adults. This may provide neurotrophic support for axonal extension and functional recovery.

The distal transected cords of infant rats are more permissive for axon extension than those of adults. To elucidate the biomolecular basis for this phenomenon, we examined the expression pattern of neurocan using semi-quantitative reverse transcription polymerase chain reaction and immunostaining in the distal cord of both adult and infant rats after transection. Neurocan is a chondroitin sulfate proteoglycan with well-documented axon growth-inhibitory properties in the central nervous system. Neurocan mRNA was up-regulated in the distal cord of adult rats shortly after transection, followed by a longer wide distribution of neurocan immunoreactivity (IR) in both neurons and astrocytes; by contrast, upregulation of neurocan mRNA was not seen in infant rats, although transient expression of neurocan IR was seen in neurons. Combined with the different regenerative capacity of infant and adult rats, the present results suggest that neurocan inhibits spinal cord regeneration.

In the last decade, researchers and clinicians have reported that transplantation of bone marrow stromal cells (BMSCs) promotes functional recovery after brain or spinal cord injury (SCI). However, an appropriate scaffold designed for the injured spinal cord is needed to enhance the survival of transplanted BMSCs and to promote nerve regeneration. We previously tested a honeycomb collagen sponge (HC), which when applied to the transected spinal cord allowed bridging of the gap with nerve fibers. In this study, we examined whether the HC implant combined with rat BMSCs increases nerve regeneration in vitro and enhances functional recovery in vivo. We first evaluated the neurite outgrowth of rat dorsal root ganglion (DRG) explants cultured on HC with or without BMSCs in vitro. Regeneration of neurites from the DRGs was increased by BMSCs combined with HC scaffolds. In the in vivo study, 3-mm-long HC scaffolds with or without BMSCs were implanted into the hemisected rat thoracic spinal cord. Four weeks after the procedure, rats implanted with HC scaffolds containing BMSCs displayed better motor and sensory recovery than those implanted with HC scaffolds only. Histologically, more CGRP-positive sensory fibers at the implanted site and 5-HT-positive serotonergic fibers contralateral to the implanted site were observed in spinal cords receiving BMSCs. Furthermore, more rubrospinal neurons projected distally to the HC implant containing BMSCs. Our study indicates that the application of BMSCs in a HC scaffold in the injured spinal cord directly promoted sensory nerve and rubrospinal tract regeneration, thus resulting in functional recovery.

The effectiveness of cell transplantation therapy for spinal cord injury (SCI) has been increasingly demonstrated in basic and clinical studies. Ethical considerations specific to Japan and a possible immune response justify the use of autologous cells obtained from patients with SCI. Currently available candidates for autologous cells include bone marrow stromal cells (BMSCs), Schwann cells derived from peripheral nerves, olfactory mucosal epithelial cells derived from the olfactory mucosa, and neural stem cells derived from attention-drawing induced pluripotent stem (iPS) cells. Among these, BMSCs have the advantage of being collected relatively easily from bone marrow and maintained in culture, and they are also known to have a protective effect on neural tissue. Studies have been conducted on bridging spinal cord defects with an artificial material known as a scaffold, and scaffolds made of various materials have been applied experimentally to the injured spinal cord. This review provides an overview of the results of studies in which a honeycomb collagen scaffold, as reported by us, or a macroporous scaffold made of d,l-polylactic acid combined with Schwann cells, as reported by Hurtado et al., was transplanted into the spinal cord. We also discuss the results of several studies on cell transplantation with scaffolds.

Study Design. The functional recovery of rats that underwent spinal cord transection in infancy was evaluated by multimodal examination (functional tests, electrophysiologic evaluation, tract-tracing) to determine the basis for the recovery. Objectives. To determine whether the hind limb function in rats that underwent spinal cord transection in infancy is regained completely, which descending tracts regenerate after the transection, and whether the functional recovery is correlated with axonal reconnection. Summary of Background Data. It is widely accepted that a newborn rat recovers its hind limb function after spinal cord transection even without any specific treatments. This functional recovery might be attributed to possible regeneration of some descending pathways, although there is a counterargument that well-trained spinal cord reflexes may bring about functional compensation. Methods. The thoracic spinal cord of infant rats was completely transected at Th10 when they were 2 weeks of age. Multimodal functional tests and electrophysiologic studies were performed 5 weeks later. Some recovered rats (i.e., those able to walk after the transection) underwent spinal cord retransection, with subsequent reevaluation of locomotion and muscle-evoked potentials. At 6 weeks after the initial transection, tract-tracing studies were performed in some animals. Results. A motor performance score detected the functional differences between the control and the recovered rats. Muscle-evoked potentials of hind limbs after electrical stimulation to the brain were recorded in some of the recovered rats, but never in the unrecovered rats. Moreover, the muscle-evoked potentials of the recovered rats disappeared after spinal cord retransection that resulted in loss of voluntary movement. Morphologic studies in two rats provided evidence that reconnection of rubrospinal, vestibulospinal, and reticulospinal tracts had occurred, whereas corticospinal regeneration was not detected. Conclusions. It can be concluded that the hind limb function of rats that underwent spinal cord transection in infancy was partially regained; that axonal regeneration of the rubrospinal, vestibulospinal, or reticulospinal tracts was demonstrated, whereas the reconnection of the corticospinal tract was not observed; and that the axonal regeneration of these tracts is involved in the functional recovery.

We report a case of closed rupture of the flexor tendons of the little finger caused by calcium pyrophosphate dihydrate crystal deposition disease of the pisotriquetrum joint. The patient could not flex the little finger and did not have wrist pain. Plain radiographs of the affected wrist joint showed severe arthritic changes of the pisotriquetrum joint and calcification around the joint. At operation, the pisotriquetrum joint capsule was ruptured and involved the flexor tendon of the little finger. The distal stump of the flexor tendon was transferred to the flexor tendon of the ring finger, and the pisiform was resected. Histological examination with polarized light microscopy revealed crystals showing weakly positive birefringence in the calcification.

Background: Fragility fractures of the distal radius are associated with an increased risk of future hip and spine fracture so the importance of body balancing ability and bone quality in fall and secondary fracture prevention is well recognized. We assessed body balancing ability, grip strength (GS), and bone quality of patients with distal radius fractures who underwent surgery. Methods: A prospective multicenter study, approved by institutional review board (IRB), of 94 women (age, >45 years) with their first fragility fracture of the distal radius who underwent surgery in registered hospitals from January to December in 2015 was conducted. Two weeks after surgery, their body balancing ability was measured by 4 methods: Functional Reach Test (FRT), Timed Up and Go (TUG) test, 2-Step Test (2ST), and Timed Unipedal Stance (TUS) test with eyes open. 2ST is the score obtained by dividing height by the maximum length of the double stride. GS on the nonfracture side and bone density ( T-score) were also measured at the same time point. Statistical analysis was performed using the Student’s t test to compare the results with Japanese normative values, and P < .05 was considered significant. Results: FRT was 29.6 cm in women in their 40s ( P = .03), 31.1 cm in women in their 50s ( P = .002), 32.5 cm in women in their 60s ( P < .001), and 28.2 cm in women in their 70s ( P < .001). TUG was 7.7 seconds in women in their 50s ( P < .001), 7.1 seconds in women in their 60s ( P = .002), and 8.1 seconds in women in their 70s ( P = .004). 2ST was 1.40 in women in their 40s ( P = 0.20), 1.32 in women in their 50s ( P = .003), 1.29 in women in their 60s ( P < .001), 1.21 in women in their 70s ( P < .001), and 1.02 in women in their 80s ( P = .01). TUS was 55 seconds in women in their 60s ( P < .001). GS was 20.9 kg in women in their 50s, 19.3 kg in women in their 60s, and 18.2 kg in women in their 80s. Only 25% of participants showed a lower T-score than −2.5. Summary: (1) Patients with distal radius fractures in their 50s, 60s, and 70s showed significantly lower body balancing ability, especially during dynamic motion like FRT, TUG, and 2ST. GS was also significantly lower in women in their 50s, 60s, and 80s. (2) Three-quarters of patients did not show osteoporosis. This is compatible with the fact that distal radius fractures tend to be primary fragility fracture, and patients were relatively younger. (3) Patients with distal radius fractures should be identified as those at “high risk” of falls and secondary fractures. Intensive training could be effective for fall prevention.

Olecranon fractures are a common injury in fractures. The tension band technique for olecranon fractures yields good clinical outcomes; however, it is associated with significant complications. In many patients, implants irritate overlying soft tissues and cause pain. This is mostly due to protrusion of the proximal ends of the K-wires or by the twisted knots of the metal wire tension band. Below we described 2 cases of olecranon fractures treated with a unique technique using FiberWire without any metallic implants. Technically, the fragment was reduced, and two K-wires were inserted from the dorsal cortex of the distal segment to the tip of the olecranon. K-wire was exchanged for a suture retriever, and 2 strands of FiberWire were retrieved twice. Each of the two FiberWires was manually tensioned and knotted on the posterior surface of the olecranon. Bony unions could be achieved, and patients had no complaint of pain and skin irritation. There was only a small loss of flexion and extension in comparison with that of the contralateral side, and the patient did not feel inconvenienced in his daily life. Using the method described, difficulty due to K-wire or other metallic implants was avoided.

We developed a honeycomb-shaped lyophilized Type I atelocollagen (Honeycomb Collagen: HC) with different pore sizes, and the effectiveness of the honeycomb shape on nerve regeneration was examined. We analyzed neurite outgrowth of dorsal root ganglion (DRG) explants on HC, both in vitro and, with direct implantation of HC into the defects of adult rat spinal cords, in vivo. The neurites of DRGs on HC extended linearly through the pores. HC with a 400 microm-pore size enhanced neurite extension, and YIGSR laminin peptide coating to the HC extended more neurites than fibronectin coating. The HC scaffolds coated with YIGSR were implanted into 2 mm-defects of spinal cords at the level of T8-9. Four weeks after implantation, the implants had degraded and been replaced with self-tissues, repairing the injured site. Neurofilament-positive fibers were observed in the implantation area and passed the borders between the HC and spinal cord stumps. Functionally, a motor-evoked potential was observed in the quadriceps femoris muscle 10 weeks after implantation. The electrophysiological examination showed reconstruction of axon tracts over the implant. This result indicates that our developed honeycomb shape is advantageous for host spinal cord compared to the random pored sponge shape, and that it promotes axonal regeneration after spinal cord injury.

The Stener lesion of the ulnar collateral ligament of the metacarpophalangeal (MP) joint of the thumb is characterized by an interposition of the adductor aponeurosis between a distally avulsed ligament and its insertion into the base of the proximal phalanx. Stener-like lesions of the MP joint of the finger have been previously reported in only a few cases.The authors experienced 38 cases of collateral ligament injuries of the MP joint of the finger. The two most frequently affected sites were the radial side of the little finger (21 cases) and the radial side of the ring finger (8 cases). We have previously reported some of these cases (22 cases), as well as clinical features and arthrographic findings. One Stener-like lesion in a collateral ligament injury of the MP joint of the ring finger was also reported earlier (Ishizuki, 1988). Additionally, Stener-like lesions were found postoperatively in six of eight cases surgically treated for collateral ligament injuries of the MP joint of the finger (little finger involvement in 5 cases and long finger involvement in 1 case).We experienced six cases of a Stener-like lesion of the MP joint of the finger. In five of these cases the distally avulsed collateral ligament was trapped by the opened window of the injured sagittal band. In the other case the ligament was avulsed at a proximal site, and the ruptured end was trapped by the sagittal band. All of the little fingers involving Stener-like lesions were abducted and unable to adduct. Therefore, an abducted little finger is an important sign of this lesion and is considered to warrant surgical treatment. Arthrograms provided information useful for identifying the lesions. In the radial three fingers, palpation of the tumor at the level of the collateral ligament may also be an important examining tool for identifying a displaced ruptured collateral ligament of the MP joint of the finger.We experienced six cases of Stener-like lesions of the MP joint of the finger. In all cases, the avulsed collateral ligament was trapped by the ruptured sagittal band. Surgical treatment was thought to be indicated in these cases. Therefore, it is important to avoid overlooking Stener-like lesions of the MP joint of the finger.

The central nervous system (CNS) has a limited capacity for regeneration after injury. In spinal cord injury (SCI) patients, total loss of all motor and sensory function occurs below the level of injury. Advances in treatment are expected for orthopedic and spinal surgeons. Recently, evidence of axonal regeneration and functional recovery has been reported in animal spinal cord injury models. Our studies on the roles of inhibitory molecules with a comparison between neonatal and adult animals may help serve as therapeutic targets to enhance axonal regeneration for the injured spinal cord. Also, our cell replacement study indicates the possibility of transplanting neural stem cells to supply the cell source for immature oligodendrocytes, which are thought to be essential for both the myelination and trophic support of regenerating axons in the spinal cord. Administration of neurotrophic factors, prevention of inhibitory factors, and stem cell technology have clinical applications in SCI patients. However, spinal cord regeneration involves a multistep process, and several factors have to be controlled after injury. A combination of several treatments could overcome a nonpermissive environment for spinal cord regeneration. Further understanding of the mechanisms and finding optimal targets of spinal cord regeneration are necessary to obtain successful therapies for SCI patients.

BackgroundSome patients with mallet fractures who undergo extension block pinning complain of exposed wires, which delay their return to sports and causes inconvenience while performing tasks that require the use of hands during the early postoperative period. The purpose of this retrospective study was to present and evaluate a novel surgical procedure for mallet fractures.MethodsWe treated 20 patients (14 males and six females; mean age, 38.4 years; range 17-68 years) with displaced mallet fractures involving >30 % of the articular surface using the closed reduction and microscrew fixation between January 2009 and January 2012. The distal interphalangeal joint (DIP) joint was immobilized with a splint for 1-3 weeks on an individual case basis. According to Wehbe and Schneider’s classification, there were 12 type IB, six type IIB, and two type IA fractures. The mean follow-up duration was 12.6 months (range 6-31 months).ResultsBone union was achieved in all patients within a mean period of 6.8 weeks, with no incidence of infection, skin necrosis, permanent nail deformity, or secondary osteoarthritis. Only two complications—temporary nail ridging in one patient and a dorsal bump caused by the screw in one patient—were observed. Minimum postoperative displacement was observed in one patient, for whom immobilization with a splint was continued for 4 weeks. Articular incongruity was