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Ulnar shortening osteotomy (USO), as its name implies, is used to shorten the ulna. It subsequently tightens the triangular fibrocartilage complex (TFCC) and ulnar wrist. TFCC foveal insertion is a primary stabilizer of the distal radioulnar joint. It is unclear whether USO is effective in TFCC foveal injuries. The purpose of this study was to review the clinical outcomes of ulnar shortening osteotomies with and without TFCC foveal injuries.We retrospectively reviewed patients with ulnar wrist pain treated with USO and wrist arthroscopy including the distal radioulnar joint (DRUJ). Sixty-five patients were included in this study. An algorithm was used to guide surgical decision-making. After arthroscopic confirmation of ulnar impaction syndrome, we performed USO with a locking compression plate (mean length of shortening, 2.7 mm; range, 1-7.5 mm). The flattened TFCC disc due to ulnar shortening was confirmed arthroscopically. If the DRUJ was unstable after USO, we repaired the TFCC foveal insertion.There were 32 post-traumatic and 33 idiopathic cases. We detected TFCC disc injuries in 34 wrists and TFCC foveal injuries in 33 wrists; both types were found in 15 wrists. TFCC foveal injuries were not significantly correlated with patient age, history of trauma, or clinical outcome. Most patients showed good clinical outcomes; 31 of 65 patients had preoperative DRUJ instability, with a significant number having foveal but not disc injuries.USO achieved reasonable outcomes, even in patients with TFCC foveal injuries. In cases demonstrating ulnar impaction, USO should be prioritized over TFCC repair.

Background Most surgeons are unaware that idiopathic neuropathy, which occurs independently of mechanical injury, can present as postoperative peripheral neuropathy. The aim of this study was to reveal the presence of postoperative neuropathy considered to be induced by surgical stress and to make surgeons aware that idiopathic neuropathy can occur postoperatively. Methods We conducted a survey among orthopedic surgeons regarding patients with postoperative neuropathies of unknown cause. For each case, the type of neuropathy, preceding surgery and anesthesia, patient background, clinical findings, and clinical course were investigated. Results Seven patients were identified. The mean time from surgery to the onset of neuropathy was 9.3 days (range 1–15 days). Five of the patients fully recovered spontaneously within 1 year, while the remaining two underwent neurolysis. One patient presented with hourglass-like constrictions in the radial nerve. No inflammatory cells were found in the epineurium of the affected nerve. Conclusions Although it is rare, postoperative idiopathic neuropathy occurs in clinical practice, and it is crucial that surgeons recognize the existence of this neuropathy to elucidate its pathogenesis as well as to reduce the risk of litigation.

Although good clinical results have been reported following lunate resection and vascularized os pisiform transfer for advanced stages of Kienböck's disease, the occurrence of wrist osteoarthritis has been highlighted. We aimed to investigate the postoperative condition of the pisiform and the surrounding bones in patients who underwent surgery for advanced stages of Kienböck's disease using magnetic resonance imaging. We retrospectively reviewed the data of six patients (mean age, 45 years; Lichtman stage, IIIb) who underwent lunate resection and vascularized os pisiform transfer for advanced stages of Kienböck's disease and postoperative magnetic resonance imaging examination. We extracted clinical data on pre- and postoperative range of motion, grip strength, wrist pain, Hand20 and Lichtman's criteria, and pre- and postoperative radiographic and magnetic resonance imaging examinations. Bone marrow lesions in the transferred pisiform were found in five patients. Signal changes of bones around the transferred pisiform were found in these five patients; the greatest change was observed in the capitate bone in three patients. These signal changes were found in the opposite parts of the bones around the transferred pisiform. No patient exhibited signal changes in the transferred pisiform bone only. Wrist osteoarthritis after lunate resection and vascularized os pisiform transfer for advanced stages of Kienböck's disease is more likely to be attributed to the low congruency of the transferred pisiform and surrounding bones than to the compromised perfusion of the pisiform. Signal changes in the opposite bone parts around the transferred pisiform were confirmed in all patients with signal changes in the pisiform.

Objectives : To assess how patient characteristics and study design influence the effectiveness of control interventions in hand OA trials. Methods : The study protocol was registered in PROSPERO (CRD42020163473). Two authors independently searched four electronic databases from their inception to December 31, 2019. Randomized and non-randomized controlled hand OA trials were included if pain intensity was assessed using a validated scale. We allocated control groups into one of the following: placebo, add-on treatment, no treatment, or active treatment. The standardized mean differences (d) of pain, as well as subjective function and hand strength, were pooled with 95% confidence intervals (CI) and 90% prediction intervals using random-effects models. Meta-regression and post-hoc subgroup analyses were performed to investigate which factors potentially impacted placebo analgesia and between-study heterogeneity. Results : Thirty-one placebo, 11 add-on, 12 no-treatment, and 10 active-treatment controls were included in meta-analyses. Effective pain relief was observed in placebo (d = −0.50, 95% CI −0.63 to −0.37), add-on (d = −0.35, 95% CI −0.59 to −0.12), and active-treatment groups (d = −0.92, 95% CI −1.35 to −0.48). In subjective function, these treatments had smaller but beneficial effects; hand strength, contrastingly, was not improved. Placebo effects were larger when flare designs were used (d = −0.96) and more homogeneous when minimum pain thresholds were set (d = −0.46, 90% prediction intervals −0.79 to −0.14). Conclusion : Placebo, add-on, and active control treatments were more effective than the no treatment control in relieving hand pain and improving subjective function. By choosing minimum pain thresholds and flare requirements at patient enrollment, moderate pain relief may be replicated among control participants in future randomized placebo-controlled trials.

Promising treatments for upper motor neuron disease are emerging in which motor function is restored by brain–computer interfaces and functional electrical stimulation. At present, such technologies and procedures are not applicable to lower motor neuron disease. We propose a novel therapeutic strategy for lower motor neuron disease and injury integrating neural stem cell transplantation with our new functional electrical stimulation control system. In a rat sciatic nerve transection model, we transplanted embryonic spinal neural stem cells into the distal stump of the peripheral nerve to reinnervate denervated muscle, and subsequently demonstrated that highly responsive limb movement similar to that of a healthy limb could be attained with a wirelessly powered two-channel neurostimulator that we developed. This unique technology, which can reinnervate and precisely move previously denervated muscles that were unresponsive to electrical stimulation, contributes to improving the condition of patients suffering from intractable diseases of paralysis and traumatic injury.

Objectives Transplantation of embryonic motor neurons has been shown to improve motor neuron survival and innervation of neuromuscular junctions in peripheral nerves. However, there have been no reports regarding transplantation of sensory neurons and innervation of sensory receptors. Therefore, we hypothesized that transplantation of embryonic sensory neurons may improve sensory neuron in the skin and innervate Merkel cells and Meissner's corpuscles. Materials and methods We obtained sensory neurons from dorsal root ganglia of 14-day rat embryos. We generated a rat model of Wallerian -degeneration by performing sciatic nerve transection and waiting for one week after. Six months after cell transplantation, we performed histological and electrophysiological examinations in naive control, surgical control, and cell transplantation groups. Results The number of nerve fibers in the papillary dermis and epidermal-dermal interface was significantly greater in the cell transplantation than in the surgical control group. The percent of Merkel cells with nerve terminals, as well as the average number of Meissner corpuscles with nerve terminals, were higher in the cell transplantation than in the surgical control group, but differences were not significant between the two groups. Moreover, the amplitude and latency of sensory conduction velocity were evoked in rats of the cell transplantation group. Conclusions We demonstrated that transplantation of embryonic dorsal root ganglion cells improved sensory nerve fiber number and innervation of Merkel cells and Meissner's corpuscles in peripheral nerves. This article is protected by copyright. All rights reserved.

Neural cell transplantation targeting peripheral nerves is a potential treatment regime for denervated muscle atrophy. This study aimed to develop a new therapeutic technique for intractable muscle atrophy by the xenotransplantation of neural stem cells derived from pig fetuses into peripheral nerves. In this study, we created a denervation model using neurotomy in nude rats and transplanted pig-fetus-derived neural stem cells into the cut nerve stump. Three months after transplantation, the survival of neural cells, the number and area of regenerated axons, and the degree of functional recovery by electrical stimulation of peripheral nerves were compared among the gestational ages (E 22, E 27, E 45) of the pigs. Transplanted neural cells were engrafted at all ages. Functional recovery by electric stimulation was observed at age E 22 and E 27. This study shows that the xenotransplantation of fetal porcine neural stem cells can restore denervated muscle function. When combined with medical engineering, this technology can help in developing a new therapy for paralysis.

Background:Disruption of the lateral collateral ligament complex (LCLC) causes posterolateral rotatory instability (PLRI). This is usually post-trauma but may also result from lateral epicondylitis. The present study examined the amount of posterior translation of the radial head related to LCLC injury, Common extensor tendon (CET) injury, and Baker classification in patients with lateral epicondylitis.Methods:We retrospectively evaluated the findings for patients with lateral epicondylitis of the humerus who underwent surgery at our institution between April 2016 and July 2021. Fifteen elbows with preoperative coronal and sagittal MR images were included. We evaluated posterior translation of the radial head on sagittal elbow MRI and compared it according to LCLC and CET lesion classifications in lateral epicondylitis.Results:Mean patient age was 49 years. All patients received single or multiple steroid injections before surgery. In the LCLC classification, four, nine, and two lesions were classified as LCLC0, LCLC1, and LCLC2, respectively. The mean radio-humeral distance (RHD) values for the LCLC lesions were 0.65 mm in LCLC0, 2.46 mm in LCLC1, 2.22 mm in LCLC2. RHD was significantly greater in LCLC1 than in LCLC0. In the CET classification, five, six, and four lesions were classified as CET1, CET2, and CET3, respectively. The mean RHD values for the CET lesions were 1.33 mm in CET1, 2.68 mm in CET2, 1.48 mm in CET3.Conclusions:Posterior translation of the radial head on MRI in patients with lateral epicondylitis is greater in cases with LCLC lesions than in those with normal findings.

Trigger finger is a common hand disorder; however, its pathogenesis remains unknown. In this study, we aimed to investigate mast cells, fibroblast activators that synthesize collagen, in the tendon sheaths of trigger fingers. We investigated the presence of mast cells and their association with changes in the collagen content of the tendon sheath and clinical data. We performed a multicenter prospective study of 77 adult patients with trigger finger who had undergone resection of the first annular pulley between August 2012 and January 2020. The tendon sheath was immunostained with an anti-tryptase antibody to confirm mast cell presence. The percentage of collagen in the tendon sheath was determined by picrosirius red staining observed through a polarization microscope. The clinical data, including the duration from symptom onset to surgery, severity, pain numerical rating scale, and Hand20 scores, were evaluated. Tryptase-positive mast cells were recognized in 83.5% of all specimens. The mast cell presence group (Group P) had a significantly higher percentage of type-3 collagen in the tendon sheath than the non-mast cell presence group (Group N) (Group P, 15.6%; Group N, 12.7%

Introduction In this study we aimed to clarify the association between interleukin-6 (IL-6) secretion in fibroblasts in carpal tunnel syndrome (CTS) patients and their biophysical parameters, including association with trigger finger and whether tranilast inhibits IL-6 secretion in fibroblasts. Methods Fibroblasts were obtained from tenosynovial tissue harvested from idiopathic CTS patients undergoing carpal tunnel release and tenosynovectomy and cultured in media containing tranilast with or without tumor necrosis-α (TNF-α) or interleukin-1β (IL-1β). Their proliferation was evaluated and secreted IL-6 levels and IL-6 mRNA expression were quantified. Correlations between IL-6 concentration and patient characteristics were examined. Results IL-6 secretion was significantly associated with trigger finger (P = .001). Tranilast inhibited fibroblast proliferation in a dose-dependent manner and suppressed IL-6 secretion. Discussion IL-6 overproduction in tenosynovial tissue may account for the association between CTS and trigger finger. Future studies should investigate whether tranilast can be used to treat patients with CTS.

Purpose: To investigate multidimensional pain intensity and quality after collagenase Clostridium histolyticum (CCH) injection in patients with Dupuytren contracture using a pain visual analog scale (VAS) and the revised version of the Short-Form McGill Pain Questionnaire (SF-MPQ-2). Methods: This prospective observational study was carried out from 2015 to 2017. As a primary end point, patients completed the pain VAS (range, 0 [no pain] to 100) and SF-MPQ-2 before and after CCH injection; 3, 9, and 24 hours after CCH injection; after the extension procedure; and 3 and 7 days after CCH injection. In addition, they reported the dose and duration of supplementary analgesic use during this period. Results: A total of 41 patients were enrolled in this study (51 joints). Mean pain VAS score (mean ± SD, 34 ± 21) was maximal 9 hours after CCH injection and decreased within the following 7 days. The total score of the SF-MPQ-2 significantly increased after CCH treatment and decreased in the 7 days after the injection. Among the SF-MPQ-2 subscales, the highest and lowest scores after CCH injection were recorded for continuous pain and affected descriptors, respectively. Nonsteroidal anti-inflammatory drugs were most frequently self-administered during 7 days after the extension procedure compared with any other study period. Conclusions: The pain VAS and SF-MPQ-2 revealed acute pain after CCH injection. However, all examined pain aspects dramatically improved within 7 days after injection. Pain after CCH injection is characterized by low scores in the Affective Descriptors subscale of the SF-MPQ-2. Type of study/level of evidence: Prognostic Ⅳ. Key words: Dupuytren contracture, Pain, Revised version of Short-Form McGill Pain Questionnaire

Highlights • Osteoid osteoma misdiagnosed as de Quervain’s tenosynovitis. • Osteoid osteoma of the wrist which is an unusual location. • Osteoid osteoma grew up in three years. • Patient history, physical examination, and timely diagnosis are important., Introduction Osteoid osteomas are benign bone tumors that can occur in various bones throughout the body but are mainly found in the long bones. Presentation of the case We report the case of a patient who had been treated for more than three years for a case of de Quervain’s tenosynovitis due to tenderness in the first compartment of the right wrist joint. An X-ray on his first visit to a clinic was normal, but it was eventually discovered that he had an osteoid osteoma of the wrist. Discussion The age of onset and gender proclivity of each disease should be considered. An X-ray should be taken in cases such as this, even to diagnose tendonitis. When any symptom, such as pain, has lingered for a long time and resisted treatment, we must reconsider the diagnosis. In patients with a low risk of tendonitis, it is essential to consider the possibility of other diseases if there is no improvement after treatment. As this patient’s tumor was missed on the initial X-ray, it grew to a mature case of osteoid osteoma in three years. Conclusion We experienced a very educational case of osteoid osteoma of the wrist misdiagnosed as de Quervain’s tenosynovitis.

Motoneuron transplantation into peripheral nerves undergoing Wallerian degeneration may have applications in treating diseases causing muscle paralysis. We investigated whether functional reinnervation of denervated muscle could be achieved by early or delayed transplantation after denervation. Adult rats were assigned to six groups with increasing denervation periods (0, 1, 4, 8, 12, and 24 weeks) before inoculation with culture medium containing (transplantation group) or lacking (surgical control group) dissociated embryonic motoneurons into the peroneal nerve. Electrophysiological and tissue analyses were performed 3 months after transplantation. Reinnervation of denervated muscles significantly increased relative muscle weight in the transplantation group compared with the surgical control group for denervation periods of 1 week (0.042% ± 0.0031% vs. 0.032% ± 0.0020%, respectively; p = 0.009), 4 weeks (0.044% ± 0.0069% vs. 0.026% ± 0.0045%, respectively; p = 0.0023), and 8 weeks (0.044% ± 0.0029% vs. 0.026% ± 0.0008%, respectively; p = 0.0023). The ratios of reinnervated muscle contractile forces to naive muscle in the 0, 1, 4, 8, and 12 weeks transplantation groups were 3.79%, 18.99%, 8.05%, 6.30%, and 5.80%, respectively, indicating that these forces were sufficient for walking. The optimal implantation time for transplantation of motoneurons into the peripheral nerve was 1 week after nerve transection. However, the neurons transplanted 24 weeks after denervation survived and regenerated axons. These results indicated that there is time for preparing cells for transplantation in regenerative medicine and suggested that our method may be useful for paralysed muscles that are not expected to recover with current treatment.

Peripheral nerve disconnections cause severe muscle atrophy and consequently, paralysis of limbs. Reinnervation of denervated muscle by transplanting motor neurons and applying Functional Electrical Stimulation (FES) onto peripheral nerves is an important procedure for preventing irreversible degeneration of muscle tissues. After the reinnervation of denervated muscles, multiple peripheral nerves should be stimulated independently to control joint motion and reconstruct functional movements of limbs by the FES. In this study, a wirelessly powered two-channel neurostimulator was developed with the purpose of applying selective FES to two peripheral nerves&mdash, the peroneal nerve and the tibial nerve in a rat. The neurostimulator was designed in such a way that power could be supplied wirelessly, from a transmitter coil to a receiver coil. The receiver coil was connected, in turn, to the peroneal and tibial nerves in the rat. The receiver circuit had a low pass filter to allow detection of the frequency of the transmitter signal. The stimulation of the nerves was switched according to the frequency of the transmitter signal. Dorsal/plantar flexion of the rat ankle joint was selectively induced by the developed neurostimulator. The rat ankle joint angle was controlled by changing the stimulation electrode and the stimulation current, based on the Proportional Integral (PI) control method using a visual feedback control system. This study was aimed at controlling the leg motion by stimulating the peripheral nerves using the neurostimulator.

Background Hand osteoarthritis (OA) has a wide spectrum of clinical presentations and physical function is one of the core domains where patients suffer. The Functional Index for Hand Osteoarthritis (FIHOA) is a leading assessment tool for hand OA-related functional impairment. Our objective was to make a Japanese version of FIHOA (J-FIHOA) and validate it among Japanese hand OA patients. Methods Forward and backward translation processes were completed to create a culturally adapted J-FIHOA. A prospective, observational multicenter study was undertaken for the validation process. Seventeen collaborating hospitals recruited Japanese hand OA patients who met the American College of Rheumatology criteria. A medical record review and responses to the following patient-rated questionnaires were collected: J-FIHOA, Hand20, Health Assessment Questionnaire (HAQ), numerical rating scale for pain (NRS pain) and Short Form 36 Health Survey (SF-36). We explored the structure of J-FIHOA using factor analysis. Cronbach’s alpha coefficients and item-total correlations were calculated. Correlations between J-FIHOA and other questionnaires were evaluated for construct validity. Participants in clinically stable conditions repeated J-FIHOA at a one- to two-week interval to assess test-retest reliability. To evaluate responsiveness, symptomatic patients who started new pharmacological treatments had a 1-month follow-up visit and completed the questionnaires twice. Effect size (ES) and standardized response mean (SRM) were calculated with pre- and post-treatment data sets. We assessed responsiveness, comparing ES and SRM of J-FIHOA with other questionnaires (construct approach). Results A total of 210 patients participated. J-FIHOA had unidimensional structure. Cronbach’s alphas (0.914 among females and 0.929 among males) and item-total correlations (range, 0.508 to 0.881) revealed high internal consistency. Hand20, which measures upper extremity disability, was strongly correlated with J-FIHOA (r = 0.82) while the mental and role-social components of SF-36 showed no correlations (r = − 0.24 and − 0.26, respectively). Intraclass correlation coefficient for test-retest reliability was 0.83 and satisfactory. J-FIHOA showed the highest ES and SRM (− 0.68 and − 0.62, respectively) among all questionnaires, except for NRS pain. Conclusions Our results showed J-FIHOA had good measurement properties to assess physical function in Japanese hand OA patients both for ambulatory follow-up in clinical practice, and clinical research and therapeutic trials.

Background: The purpose of this study was to identify predictive factors of poor response to intra-flexoral sheath corticosteroid injection, as well as to identify factors associated with patients’ decisions to undergo surgical treatment. Methods: Data from 112 patients who received steroid injection treatment for trigger finger were reviewed retrospectively. Logistic regression was used to assess the prognostic value of factors assumed to affect prognosis (age, sex, underlying disease, history of illness, presence of carpal tunnel syndrome, multiple digit involvement, and pre- and post-operative disability scores). Results: Multiple digits were affected in 42 patients. Associated and underlying conditions were carpal tunnel syndrome (n = 36), hypertension (n = 23), hyperlipidemia (n = 14), and history of malignant tumor (n = 10). Logistic regression analysis showed that multiple digit involvement and Froimson clinical severity score were factors significantly associated with surgical treatment after intra-flexoral sheath corticosteroid injection treatment. These two factors were also found to be associated with the patients’ decisions to undergo surgical treatment. Conclusions: Although local corticosteroid injection is useful in most cases, providers need to counsel patients with multiple digit involvement and/or severe cases about the possibility of requiring additional surgical treatment.

Malrotation is common after oblique or spiral proximal and middle phalangeal fractures. Although a small degree of malrotation may be acceptable for many patients, greater degrees of malrotation result in functional impairment, pain due to distortion of the joints, and diminished grip strength [1]. Osteotomy is usually required, preferably through the phalanx. Recent progress in computed tomography (CT) imaging and computer technology has enabled clinicians to evaluate the 3-dimensional (3D) kinematics of joint motion and to simulate accurate 3D corrective osteotomy using CT bone models [2,3]. We developed a novel simulation system named “linkage simulation” in which each phalanx is considered a linked arm, which makes it possible to analyze multiple joint motions preoperatively. Here, we report the case of a patient with a malunited little finger proximal phalangeal fracture that was successfully treated using the linkage simulation system. This system consisted of an original 3D computer program, which was designed to reproduce preoperative 3D motion. We have not identified any previous reports of corrective osteotomy for a malunited upper extremity fracture using 3D kinematics and linkage simulation.

Background A forearm band is frequently used for lateral epicondylitis worldwide. However, evidence regarding its efficacy has been insufficient. The objective of this prospective, randomized, controlled trial was to analyze the effects of a forearm band for treatment of lateral epicondylitis at 1, 3, 6, and 12 months. Methods Patients with lateral epicondylitis were randomly allocated into a band (n = 55) or non-band (n = 55) group. Patients in the band group were instructed to wear a forearm band for more than 6 h daily for at least 6 months. Patients in both groups were instructed to perform wrist extensor stretching exercises for 30 s, 3 times daily, for 6 months. Hand10, pain, and satisfaction scores, and proportions of positive physical examinations, including tenderness assessment, Thomsen test, and middle finger extension test, were evaluated at 1, 3, 6, and 12 months after enrollment. Results There were no significant differences between the band and non-band groups with regard to Hand10, pain, or satisfaction scores at 1, 3, 6, and 12 months. Likewise, there was no significant difference in proportions of positive physical examinations between groups at 1, 3, 6, and 12 months. Conclusion The results of the current study suggest that a forearm band may have no more than a placebo effect, and do not support the use of a forearm band based on its effectiveness.

To investigate multidimensional pain intensity and quality after collagenaseThis prospective observational study was carried out from 2015 to 2017. As a primary end point, patients completed the pain VAS (range, 0 [no pain] to 100) and SF-MPQ-2 before and after CCH injection; 3, 9, and 24 hours after CCH injection; after the extension procedure; and 3 and 7 days after CCH injection. In addition, they reported the dose and duration of supplementary analgesic use during this period.A total of 41 patients were enrolled in this study (51 joints). Mean pain VAS score (mean ± SD, 34 ± 21) was maximal 9 hours after CCH injection and decreased within the following 7 days. The total score of the SF-MPQ-2 significantly increased after CCH treatment and decreased in the 7 days after the injection. Among the SF-MPQ-2 subscales, the highest and lowest scores after CCH injection were recorded for continuous pain and affected descriptors, respectively. Nonsteroidal anti-inflammatory drugs were most frequently self-administered during 7 days after the extension procedure compared with any other study period.The pain VAS and SF-MPQ-2 revealed acute pain after CCH injection. However, all examined pain aspects dramatically improved within 7 days after injection. Pain after CCH injection is characterized by low scores in the Affective Descriptors subscale of the SF-MPQ-2.Prognostic Ⅳ.

Objectives Muscle spindles are proprioceptive receptors in the skeletal muscle. Peripheral nerve injury results in a decreased number of muscle spindles and their morphologic deterioration. However, the muscle spindles recover when skeletal muscles are reinnervated with surgical procedures, such as nerve suture or nerve transfer. Morphological changes in muscle spindles by cell transplantation procedure have not been reported so far. Therefore, we hypothesized that transplantation of embryonic sensory neurons may improve sensory neurons in the skeletal muscle and reinnervate the muscle spindles. Materials and methods We collected sensory neurons from dorsal root ganglions of 14‐day‐old rat embryos and prepared a rat model of peripheral nerve injury by performing sciatic nerve transection and allowing for a period of one week before which we performed the cell transplantations. Six months later, the morphological changes of muscle spindles in the cell transplantation group were compared with the naïve control and surgical control groups. Results Our results demonstrated that transplantation of embryonic dorsal root ganglion cells induced regeneration of sensory nerve fibre and reinnervation of muscle spindles in the skeletal muscle. Moreover, calbindin D‐28k immunoreactivity in intrafusal muscle fibres was maintained for six months after denervation in the cell transplantation group, whereas it disappeared in the surgical control group. Conclusions Cell transplantation therapies could serve as selective targets to modulate mechanosensory function in the skeletal muscle.

Background Hand osteoarthritis (HOA) is a highly prevalent and heterogeneous musculoskeletal disorder. Although well-designed clinical trials and guidelines have been published, there are comparatively few HOA studies concerning Asian countries. To both pursue appropriate clinical courses for patients and to engage in future research, physicians need to discriminate symptomatic HOA. The Functional Index for Hand OsteoArthritis (FIHOA) assesses hand OA-related functional impairment and is accepted as a gold standard with excellent reliability and responsiveness[1,2]. Objectives Our objective was to make a Japanese version of the FIHOA (J-FIHOA) and to validate it among Japanese HOA patients. Methods J-FIHOA was created following forward/backward translation processes distilled from the established guidelines. A prospective, multicenter study was undertaken for its validation. Seventeen collaborating hospitals recruited hand OA patients from September 2017 to September 2018. Patients who met the ACR classification criteria were included. A medical record review and the following patient-rated questionnaires were collected: J-FIHOA, Japanese Health Assessment Questionnaire (J-HAQ), numerical rating scale for pain (NRS pain) and Japanese Short Form 36 Health Survey (J-SF-36). As item 7 is a gender-role question, an item total correlation needed to be calculated independently for women and men.The J-FIHOA scores at enrollment were used to assess Cronbach’s alpha coefficient/item-total correlation and compared with the J-HAQ, NRS pain and J-SF-36 yielding respective Spearman’s rank correlation coefficients. To assess reliability, we used test-retest methods for patients with unchanged symptoms/treatments. The interval was 1-2 weeks and data sets were assessed with the intraclass correlation coefficient (ICC). To evaluate responsiveness, those who started new pharmacological treatments were required to answer the questionnaires and to have a 1-month follow-up visit. Differences between pre- and post- pharmacological treatments were used to calculate the effect size (ES). Results Twenty-nine male and 145 female HOA patients participated (mean age 65 years). Cronbach’s alpha was 0.91, showing high internal consistency. Each item was well correlated with the total score (all values >0.30; range 0.46 to 0.89). Construct validity between J-FIHOA and other scales was: 0.73 (J-HAQ), 0.56 (NRS pain), -0.31 (J-SF-36 physical component) and -0.21 (J-SF-36 mental component). Although the FIHOA has no pain-related question, previous reports showed moderate correlations between the FIHOA and pain. Our results were concordant with these reports. It was expected that J-SF-36 mental component had the weakest correlation. One hundred fifty-seven longitudinal data sets were pooled and used to evaluate reliability (137 for test-retest) and responsiveness (20 for ES). ICC for test-retest was 0.83 (95% CI, 0.77 to 0.88). The ES were 0.56 for J-FIHOA and 0.44 for J-HAQ. We assumed that this higher ES related on the HOA specificity of J-FIHOA. Conclusion We created a cross-culturally adapted J-FIHOA. Our results showed its good metric qualities to assess dysfunction in HOA and equivalence with the original FIHOA. References [1] Dreiser RL, Maheu E, et al. Validation of an algofunctional index for osteoarthritis of the hand. Revue du rhumatisme (English ed). 1995; 62(6 Suppl 1):43s-53s. [2] Dreiser RL, Maheu E, et al. Sensitivity to change of the functional index for hand osteoarthritis. Osteoarthritis Cartilage. 2000; 8:S25-S28. Disclosure of Interests None declared

BACKGROUND The upper extremity disability in patients with carpal tunnel syndrome (CTS) is related to dysfunction due to the median nerve damage. However, there is no report on which dysfunctions affect the upper extremity disability. PURPOSE This study aimed to investigate which clinical factors influence upper extremity disability in women with CTS. METHODS We analyzed 60 hands of women with bilateral idiopathic CTS. Upper extremity disability was assessed using Hand10, a validated and self-administered tool. Pain intensity was measured using the Japanese version of the Short-Form McGill Pain Questionnaire (SF-MPQ-J). We performed nerve conduction studies, assessed physical and psychological parameters, and collected demographic data. Physical parameters comprised grip strength, pinch strength, tactile threshold, static 2-point discrimination sensation, and severity of numbness. Psychological parameters include depression, pain anxiety, and distress. RESULTS The bivariate analysis revealed that Hand10 was significantly correlated with age, symptom duration, SF-MPQ-J, grip strength, pain anxiety, and distress. Multiple regression analysis demonstrated that SF-MPQ-J and grip strength were related to Hand10 score. CONCLUSIONS Pain intensity and grip strength were dysfunctions affecting the upper extremity disability in women with bilateral idiopathic CTS. Rehabilitation approaches for CTS should be considered based on the adaptive activities of the neural networks.

Reinnervation of denervated muscle after peripheral nerve injury is important to restore functional muscle activity. Recently, functional electrical stimulation (FES) to peripheral nerves has been demonstrated to be an effective method to restore muscle function. In this paper, a wirelessly powered neurostimulator was developed to conduct FES to a peripheral nerve. The neurostimulator uses a magnetic field resonance method to supply power wirelessly from a transmitter coil to a receiver coil. The receiver coil is connected to a peripheral nerve and implanted into a rat body. The developed neurostimulator is portable, and the stimulation voltage is adjustable from 2.6 V to 5.0 V. The flexion of rat ankle was observed when the rat peroneal nerve was stimulated by the developed neurostimulator. This research aims at restoring function of denervated muscle by stimulating the peripheral nerve from the implanted device.

The purpose of this study was to compare the treatment results of sonography-guided arthroscopic excision for volar and dorsal wrist ganglions. A total of 42 patients with wrist ganglions underwent sonography-guided arthroscopic resection. Clinical outcome measures included wrist range of motion, grip strength, patient-rated questionnaire Hand20, and numerical pain rating scale. All patients were assessed for recurrence throughout the follow-up period. Ganglions were located at the dorsal wrist in 26 cases and at the volar wrist in 16 cases. The mean Hand20 and pain scores were significantly improved after sonography-guided arthroscopic resection for both volar and dorsal wrist ganglions. Recurrence was seen in six cases (23%) of dorsal wrist ganglion but no cases of volar wrist ganglion (P.05). The use of sonography-guided arthroscopic ganglion excision is better for treating volar wrist ganglion than dorsal wrist ganglion.

We hypothesized that interindividual variations in the teardrop, which represents the volar projection of the lunate facet of the distal radius, cause unsatisfactory fitting of the volar locking plate to the bone. This can cause flexor tendon ruptures. Herein, we conducted a cross-sectional study and measured the ratio of teardrop height and the teardrop inclination angle as parameters of teardrop configuration for 200 standardized lateral radiographs (average age of the patients, 51 years). We also quantified the influence of the teardrop morphology by analyzing the fit of three locking plates to three radii with differing teardrop inclination angles using a three-dimensional computer-aided design system. The average ratios of the teardrop height and teardrop inclination angle were 0.42° (0.30-0.56°) and 28.8° (9.9-44.9°), respectively. The teardrop inclination angle was moderately correlated with age in men but not in women. In the plate-to-bone fit analyses, the fit of all the plates was significantly different between bones, with the configuration of the radius with the lowest teardrop inclination angle being the closest approximation to that of each plate. We demonstrated the interindividual variation in the shape of the teardrop and its influence on the fit of the volar plate, highlighting the importance of careful plate selection for achieving osteosynthesis of bones with a high teardrop inclination angle. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:953-960, 2016.

In this paper, a wireless powered neurostimulator was fabricated using a magnetic field resonance method. The power to stimulate peripheral nerve was supplied from a transmitter coil to a receiver coil which is connected to a peripheral nerve. In vivo test was conducted by stimulating a rat sciatic nerve using fabricated neurostimulator, and the motion of hind leg was observed corresponds to the stimulation. A portable transmitter coil system was developed using lithium-ion battery as a power source of transmitter system. This research aims at restoring function of denervated muscle by stimulating the peripheral nerve from the implantable device.

Neurogenesis in the adult peripheral nervous system remains to be demonstrated. We transplanted embryonic neural stem cells into a Wallerian degenerating nerve graft and observed development of a nodular structure consisting of neurons, glia, and Schwann cells. Histological analysis revealed a structure loosely resembling the spinal cord, including a synaptic network that formed along the neuron. Furthermore, the new axons reinnervated the paralysed muscle, forming both de novo and revived neuromuscular junctions. Reinnervation of the paralysed muscle resulted in significantly greater mean wet muscle weight and muscle fibre cross-sectional area on the cell transplantation side than on the surgical control side (body weight 0.071 ± 0.011% vs. 0.051 ± 0.007%, p = .006; area 355.6 ± 345.2 vs. 114.0 ± 132.0 μm2 , p

Reinnervation of denervated muscle by motor neurons transplanted into the peripheral nerve may provide the potential to excite muscles artificially with functional electrical stimulation (FES). Here we investigated whether transplantation of embryonic motor neurons into peripheral nerve combined with FES restored functional muscle activity in adult Fischer 344 rats after transection of the sciatic nerve. One week after sciatic nerve transection, cell culture medium containing (cell transplantation group, n = 6) or lacking (surgical control group, n = 6) dissociated embryonic spinal neurons was injected into the distal stump of the tibial and peroneal nerves. Electrophysiological and tissue analyses were performed in the cell transplantation and surgical control groups 12 weeks after transplantation, as well as a in naive control group (n = 6) that received no surgery. In the cell transplantation group, ankle angle was measured during gait, with and without FES of the peroneal nerve. Ankle angle at mid-swing was more flexed during gait with FES (26.6 ± 8.7°) than gait without FES (51.4 ± 12.8°, p = 0.011), indicating that transplantated motor neurons in conjunction with FES restored ankle flexion in gait, even though no neural connection between central nervous system and muscle was present. These results indicate that transplantation of embryonic motor neurons into peripheral nerve combined with FES can provide a novel treatment strategy for paralysed muscles. Copyright © 2013 John Wiley & Sons, Ltd.

Objectives The aim of this study was to gain a better understanding of anterior interosseous nerve and posterior interosseous nerve involvement in neuralgic amyotrophy. Methods In a retrospective chart review, 51 cases (49 patients) with anterior and posterior interosseous nerve syndrome were investigated in terms of their symptoms, course of disease, and prognosis. Results Patients first presented with pain in 52.9% of cases. The location of the pain was distal to the shoulder in most cases (85.1%). Sensory involvement was found in 27.5% of patients, and patients with pain before paresis had fewer sensory symptoms (p = 0.006). Neurolysis significantly improved Hand20 scores, but conservative treatment did not (p = 0.020 vs. 0.204). Conclusions Patients with anterior interosseous nerve and posterior interosseous nerve affection in neuralgic amyotrophy had less pain. Neurolysis can be superior to conservative treatment in the patients with focal constrictions and no spontaneous recovery.

Summary Introduction This study assessed the treatment outcomes of upper extremity benign tumors using the patient-rated outcome measures of Hand20 questionnaire. Methods In total, 304 patients who underwent surgery for benign bone and soft tissue tumors of the upper limb were included. Tumors were classified into three size groups: 3 cm. Tumors were divided with respect to location: digit, hand, wrist, forearm, elbow, upper arm, or axilla. We prospectively assessed responses to the Hand20 questionnaire that was administered both before and after surgery. Results The mean Hand20 and pain scores significantly improved after surgery in patients with ganglion cysts, giant cell tumors of the tendon sheath, enchondromas, or pyogenic granulomas. For patients with hemangiomas, schwannomas, or glomus tumors, although the mean pain scores improved significantly following surgery, there were no significant changes in the mean Hand20 scores. However, the statistical power for this analysis was low. The mean Hand20 and pain scores improved significantly, regardless of the size grouping. The mean Hand20 scores significantly improved after surgery in patients with finger, thumb, hand, or wrist tumors. Except for elbow to axillary tumors, the mean pain scores significantly improved in all patients. Conclusion The results of Hand20 and pain scores suggest that most patients with benign hand tumors are indicated for surgery, but the degree of improvement differs according to tumor pathology and location but not size.

Background Recent advances in imaging modalities have enabled three-dimensional preoperative simulation. A four-dimensional preoperative simulation system would be useful for debridement arthroplasty of primary degenerative elbow osteoarthritis because it would be able to detect the impingement lesions. Methods We developed a four-dimensional simulation system by adding the anatomical axis to the three-dimensional computed tomography scan data of the affected arm in one position. Eleven patients with primary degenerative elbow osteoarthritis were included. A “two rings” method was used to calculate the flexion-extension axis of the elbow by converting the surface of the trochlea and capitellum into two rings. A four-dimensional simulation movie was created and showed the optimal range of motion and the impingement area requiring excision. To evaluate the reliability of the flexion-extension axis, interobserver and intraobserver reliabilities regarding the assessment of bony overlap volumes were calculated twice for each patient by two authors. Patients were treated by open or arthroscopic debridement arthroplasties. Pre- and postoperative examinations included elbow range of motion measurement, and completion of the patient-rated questionnaire Hand20, Japanese Orthopaedic Association-Japan Elbow Society Elbow Function Score, and the Mayo Elbow Performance Score. Results Measurement of the bony overlap volume showed an intraobserver intraclass correlation coefficient of 0.93 and 0.90, and an interobserver intraclass correlation coefficient of 0.94. The mean elbow flexion-extension arc significantly improved from 101° to 125°. The mean Hand20 score significantly improved from 52 to 22. The mean Japanese Orthopaedic Association-Japan Elbow Society Elbow Function Score significantly improved from 67 to 88. The mean Mayo Elbow Performance Score significantly improved from 71 to 91 at the final follow-up evaluation. Conclusion We showed that four-dimensional, preoperative simulation can be generated by adding the rotation axis to the one-position, three-dimensional computed tomography image of the affected arm. This method is feasible for elbow debridement arthroplasty. Electronic supplementary material The online version of this article (doi:10.1186/s12891-016-0996-9) contains supplementary material, which is available to authorized users.

We developed a novel hydrogel derived from sodium carboxymethylcellulose (CMC) in which phosphatidylethanolamine (PE) was introduced into the carboxyl groups of CMC to prevent perineural adhesions. This hydrogel has previously shown excellent anti-adhesive effects even after aggressive internal neurolysis in a rat model. Here, we confirmed the effects of the hydrogel on morphological and physiological recovery after nerve decompression. We prepared a rat model of chronic sciatic nerve compression using silicone tubing. Morphological and physiological recovery was confirmed at one, two, and three months after nerve decompression by assessing motor conduction velocity (MCV), the wet weight of the tibialis anterior muscle and morphometric evaluations of nerves. Electrophysiology showed significantly quicker recovery in the CMC-PE group than in the control group (24.0 ± 3.1 vs. 21.0± 2.1 m/s (p < 0.05) at one months and MCV continued to be significantly faster thereafter. Wet muscle weight at one month significantly differed between the CMC-PE (BW) and control groups (0.148 ± 0.020 vs. 0.108 ± 0.019%BW). The mean wet muscle weight was constantly higher in the CMC-PE group than in the control group throughout the experimental period. The axon area at one month was twice as large in the CMC-PE group compared with the control group (24.1 ± 17.3 vs. 12.3 ± 9 μm2) due to the higher ratio of axons with a larger diameter. Although the trend continued throughout the experimental period, the difference decreased after two months and was not statistically significant at three months. Although anti-adhesives can reduce adhesion after nerve injury, their effects on morphological and physiological recovery after surgical decompression of chronic entrapment neuropathy have not been investigated in detail. The present study showed that the new anti-adhesive CMC-PE gel can accelerate morphological and physiological recovery of nerves after decompression surgery.

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. Type of study/level of evidence Therapeutic IV.