松本 卓巳

Distal Chevron osteotomy is a well-established surgical procedure for mild to moderate hallux valgus deformity. Many methods have been described for fixation of osteotomy site; secure fixation, enabling large displacement of the metatarsal head, is one of the essentials of this procedure. The purpose of the present study was to evaluate the short-term radiographic outcome of a distal Chevron osteotomy using an intramedullary plate for the correction of hallux valgus deformity. The present study evaluated 37 patients (40 feet) who underwent distal Chevron osteotomy using an intramedullary plate by periodic radiographs obtained preoperatively and at 4 weeks, 8 weeks, 3 months, and 6 months postoperatively. Correction of the hallux valgus angle averaged 17.8°, intermetatarsal angle 7.4°, distal metatarsal articular angle 2.7°, and sesamoid position 1.4 stages at 3 months postoperatively. The average lateral shift of the capital fragment was 6.5 mm. All patients achieved bone union, and there were no cases of dislocation, displacement, or avascular necrosis of the metatarsal head fragment. In conclusion, a distal Chevron osteotomy using an intramedullary plate was a favorable method for the correction of mild to moderate hallux valgus deformity. Levels of Evidence: Level IV: Case series.

PURPOSE: Surgical reconstructions in three dimensions are needed for treatment of foot and ankle deformities. However, surgical results might be influenced by the skill and experience of doctors which complement the limited information for reconstructions in three dimensions. To solve these, studies were carried out to measure plantar pressure distribution during surgery. Though, it was impossible to accurately measure plantar pressure distribution accurately during operation. Therefore, we proposed an intraoperative plantar pressure measurement (IPPM) device that enables proper navigation in the push direction. METHODS: For this purpose, first, we investigated how the physiological load axis passes through the human body to identify the pushing direction of the pressure sensor of the device toward the patient's foot. In particular, we hypothesized that the physiological load axis passes through the femoral head center and we evaluated this in a measurement experiment with nine healthy subjects. Second, based on these results, we developed the IPPM device that has two force sensors to identify the pushing direction toward the femoral head center and a conductive ink sensor to measure plantar pressure distribution. Finally, we conducted the experiments with nine healthy subjects and two users. RESULTS: From the first experimental results, the physiological load axis was found to pass through the femoral head center in normal standing posture. From the evaluation experiment, there are no significant differences statistically in plantar pressure distributions between the conditions of using IPPM device and without using it for both a medical student and a surgeon. However, in some cases the plantar pressure distribution can be reproduced similarly to that of the standing posture, and also from the evaluation experiment concerning the relation between CoP position and NCC, the NCC tends to increase when the position of the CoP is closer to that at the standing posture. CONCLUSION: The IPPM device has possibility to reproduce the plantar pressure distribution during surgery and prevent the recurrence of surgical complications.

BACKGROUND: Although the complications of internal fixation in ankle fractures are well-known in a number of reports, there have been few reports revealing the complications of implant removal in ankle fractures. The aim of this study was to investigate the perioperative complications of implant removal in ankle fractures and analyze the associated factors of such complications. METHODS: Patients who underwent open reduction and internal fixation using metal implants for ankle fractures and had their implants removed between 2010 and 2015 were enrolled in the study. We investigated the rate and details of perioperative complications and collected information on the possible risk factors including the age, comorbidities, fracture type, number of skin incisions, operative time, and surgeon's grade from the medical charts. RESULTS: A total of 80 patients were included for analysis. Perioperative complications occurred in 11 patients (14%) including arterial injury in one patient, blistering in three, nerve injuries in three, skin necrosis in two, and infection in two. In patients with perioperative complications, the rate of patients with peripheral vascular disease and multiple skin incision was significantly higher (18% vs 3%, p = 0.031 and 64% vs 32%, p = 0.042, respectively) and the operative time was significantly longer (102 min vs 57 min, p < 0.001) than those without perioperative complications. CONCLUSION: The indication of implant removal in ankle fractures should be considered carefully, especially in patients with possible risk factors and without implant-related symptoms, due to the high incidence of perioperative complications.

CASE: Gorham-Stout disease (GSD) is a rare disorder characterized by massive bone destruction. Consensus is lacking on the effective treatment strategies for GSD. This report presents 2 cases of GSD, a 47-year-old man and a 72-year-old woman, involving the shoulder girdle which were successfully controlled by antiresorptive agents including bisphosphonates and denosumab, the antireceptor activator of nuclear factor-κB ligand antibody. CONCLUSIONS: These 2 cases suggest that antiresorptive agents targeting osteoclasts can be efficacious therapeutic options for GSD. This is the first case of GSD we are aware of which showed good response to denosumab treatment.

OBJECTIVES: In patients with rheumatoid arthritis (RA), the talonavicular joint is commonly involved and midfoot collapse can lead to progressive flattening of the arch. Despite a general awareness of the important structural role of the talonavicular joint in rheumatoid foot disease, details of its destructive pattern have not been elucidated. METHODS: We cross-sectionally investigated 176 RA patients (342 feet) and classified their feet into the following five groups according to radiographic findings: arthritis (RA changes with normal navicular shape), Müller-Weiss Disease (MWD) (collapse of the lateral aspect of the tarsal navicular), flat (flattened navicular), ankylosis (ankylosis of the talonavicular joint), and normal. We compared medical histories and radiographic measurements among all five groups. RESULTS: The arthritis group comprised 91 feet, 36 in the MWD group, nine in the flat group, 12 in the ankylosis group, and 194 classified as normal. The MWD group demonstrated a trend towards pes planovarus deformity in contrast to pes planovalgus deformity in the arthritis group. Corticosteroid use and the mean daily dosage were the highest in the MWD group. CONCLUSIONS: This report revealed a high prevalence of MWD-like changes to the navicular in RA patients and its association with pes planovarus deformity and corticosteroid usage.

OBJECTIVES: Although wrist arthrodesis using a plate is an established treatment with a well-documented successful union rate for severely destroyed wrists, plate-related complications are a matter of great concern. METHODS: We retrospectively compared wrist arthrodesis using an AO wrist fusion plate in nine and a locking compression plate (LCP) metaphyseal plate in seven cases of rheumatoid arthritis. RESULTS: The mean follow-up was 40.6 months in the AO wrist fusion plate group and 57.2 months in the LCP metaphyseal plate group. Bone union at the arthrodesis site was achieved in all cases in both groups. Comparison of the original position of the fusion on the immediate postoperative radiographs and the position on the most recent follow-up radiographs demonstrated good stability in both groups. Plate-related complications occurred in four cases in the AO wrist fusion plate group and no cases in the LCP metaphyseal plate group. Complications included pain over the plate, wound dehiscence and infection, extensor tendon adhesion, and fracture in one case each. CONCLUSION: Wrist arthrodesis using an LCP metaphyseal plate was favorable for rheumatoid arthritis patients with comparable stability to that of and a lower risk of plate-related complications than an AO wrist fusion plate.

Heterotopic ossification (HO) is an ectopic formation of the lamellar bone in the soft tissues. Some authors have previously reported HO or calcific tendinitis of the peroneus longus tendon at the level of the cuboid bone, while the HO of the peroneus longus tendon in the retromalleolar portion has not been reported. The purpose of this report is to describe clinical, radiological, and histological features of this rare ossification and its treatment. To the best of our knowledge, this is the first report presenting a case of HO of the peroneus longus tendon, which developed in the retromalleolar portion.

Adult-acquired flatfoot deformity is a progressive flattening of the arch of the foot that results from posterior tibial tendon insufficiency with a predilection for middle-aged women. A lateralized force vector associated with hindfoot valgus in adult-acquired flatfoot produces lateral ankle pain due to impingement at the lateral hindfoot, which can even lead to stress fractures of the distal fibula. Here, we present the rare case of a 73-year-old woman who presented with stress fractures of the bilateral taluses and unilateral distal fibula accompanied by severe adult-acquired flatfoot deformities.

We report the case of a 56-year-old female with mutilating rheumatoid arthritis, who developed severe pes planovalgus. The foot was successfully reconstructed through a combination of osteotomies, including medial displacement of the talus accompanied by resection of the medial malleolus. This maneuver enabled a ∼1-cm medial displacement of the hindfoot while minimizing the adverse effect on forefoot rotation.

OBJECTIVE: In this study, we investigated the changes in clinical outcome, treatment, and incidence of orthopedic surgery in patients with rheumatoid arthritis (RA) from 2004 to 2014. METHODS: Data were studied from the Japanese nationwide cohort database, NinJa (National Database of Rheumatic Diseases by iR-net in Japan), from 2004 to 2014. The time trends in the incidence of orthopedic procedures were analyzed using linear regression analysis. The cross-sectional annual data were compared between 2004 and 2014 to analyze the changes in clinical outcome and treatment. RESULTS: The incidence of orthopedic surgeries in patients with RA consistently decreased from 72.2 procedures per 1000 patients in 2004 to 51.5 procedures per 1000 patients in 2014 (regression coefficient = -0.0028, 95% CI -0.0038 to -0.0019, p < 0.001). The greatest reduction was found in total knee arthroplasty and total hip arthroplasty. Disease activity and functional disability improved significantly over this decade. The proportions of patients receiving methotrexate and biologic disease-modifying antirheumatic drugs significantly increased from 39.6% and 1.7% in 2004 to 63.8% and 27.4% in 2014, respectively. CONCLUSION: The overall incidence of orthopedic surgeries in patients with RA significantly decreased, accompanied by improved clinical outcomes because of the expanded use of effective drugs; however, the declining trend differed between procedures or locations. The results from the present study suggest that there might be a change in supply and demand for orthopedic surgeries.

BACKGROUND: Subtalar joint arthrodesis is a common operative treatment for symptomatic subtalar arthrosis. Because excessive relative motion between the talus and calcaneus can delay or prohibit fusion, fixation should be optimized, particularly in patients at risk for subtalar arthrodesis nonunion. Tapered, fully-threaded, variable pitch screws are gaining popularity for this application, but the mechanical properties of joints fixed with these screws have not been characterized completely. We quantified the torsion resistance of 2-screw and 3-screw subtalar joint fixation using this type of screw. METHODS: Ten pairs of cadaveric subtalar joints were prepared for arthrodesis and fixed using Acutrak 2-7.5 screws. One specimen from each pair was fixed with two diverging posterior screws, and the contralateral joint was fixed using two posterior screws and a third screw directed through the anterior calcaneus into the talar neck. Internal and external torsional loads were applied and joint rotation and torsional stiffness were measured at two torque levels. FINDINGS: Internal rotation was significantly less in specimens fixed with three screws. No difference was detectable between 2-screw and 3-screw fixation in external rotation or torsional stiffness in either rotation direction. Both 2-screw and 3-screw fixation exhibited torsion resistance surpassing that reported previously for subtalar joints fixed with two diverging conventional lag screws. INTERPRETATION: Performance of the tapered, fully threaded, variable pitch screws exceeded that of conventional lag screws regardless of whether two or three screws were used. Additional resistance to internal rotation afforded by a third screw placed anteriorly may offer some advantage in patients at risk for nonunion.

This report presents a case of stenosing tenosynovitis of the flexor hallucis longus tendon associated with the plantar capsular accessory ossicle at the interphalangeal joint of the great toe, which was confirmed by intraoperative observation and was successfully treated with surgical resection of the ossicle. As the plantar capsular accessory ossicle was not visible radiographically due to the lack of ossification, ultrasonography was helpful for diagnosing this disorder.

Osteoid osteoma in periarticular lesions tends to have an unusual presentation that likely leads to a delayed or missed diagnosis compared with a typical osteoid osteoma in the metaphysis or diaphysis of the long bone. In cases that are unresponsive to conservative treatment, surgical interventions including en bloc resection, computed tomography-guided percutaneous treatment, and arthroscopic resection have been performed; however, these methods frequently result in inadequate tumor resection and recurrence. Here we present a case of a 16-year-old girl with osteoid osteoma in the talar neck presenting as anterior impingement syndrome due to marked synovitis in the ankle joint which was successfully treated without complications by arthroscopic synovectomy and tumor resection followed by intraoperative 3D C-arm-based imaging confirming complete tumor lesion removal. Her pain was relieved immediately after the surgery, and there was no recurrence at 12 months of follow-up. This is the first case report of the surgical treatment of the osteoid osteoma in the talar neck with the combination methods of arthroscopy and 3D C-arm-based imaging.

Lateral premalleolar bursitis of the ankle is a rarely reported disorder in the English literature although it is not uncommon in Asian countries where people commonly sit on their feet. Here, we present the case of a 66-year-old woman with recalcitrant lateral premalleolar bursitis associated with lateral ankle instability which was successfully treated with surgical resection of the bursa and repair of the anterior talofibular ligament. Operative findings revealed a communication between the bursa and articular cavity of the ankle joint via the sheath of the extensor digitorum longus tendon, which was considered to act as a check valve leading to a large and recalcitrant bursitis. This report provides a novel concept about the etiology of recalcitrant lateral premalleolar bursitis of the ankle.

BACKGROUND: Joint compression is an essential element of successful arthrodesis. Although subtalar joint compression generated by conventional screws has been quantified in the laboratory, compression obtainable with headless screws that rely on variable thread pitch to achieve bony contact has not been assessed. This study measured subtalar joint compression achieved by 2 posteriorly placed contemporary headless, variable-pitch screws, and quantified additional compression gained by placing a third screw anteriorly. METHODS: Ten, unpaired fresh-frozen cadaveric subtalar joints were fixed sequentially using 2 diverging posterior screws (one directed into the talar dome, the other into the talar neck), 2 parallel posterior screws (both ending in the talar dome), and 2 parallel screws with an additional anterior screw inserted from the plantar calcaneus into the talar neck. Joint compression was quantified directly during screw insertion using a novel custom-built measuring device. RESULTS: The mean compression generated by 2 diverging posterior screws was 246 N. Two parallel posterior screws produced 294 N of compression, and augmentation of that construct with a third, anterior screw increased compression to 345 N (P < .05). Compression subsequent to 2-screw fixation was slightly less than that reported previously for subtalar joint fixation with 2 conventional lag screws, but was comparable when a third screw was added. CONCLUSIONS: Under controlled testing conditions, 2 tapered, variable-pitch screws generated somewhat less compression than previously reported for 2-screw fixation with conventional headed screws. A third screw placed anteriorly increased compression significantly. CLINICAL RELEVANCE: Because headless screws are advantageous where prominent screw heads are problematic, such as the load-bearing surface of the foot, their effectiveness compared to other screws should be established to provide an objective basis for screw selection. Augmenting fixation with an anterior screw may be desirable when conditions for fusion are suboptimal.

BACKGROUND: Total ankle arthroplasty (TAA) has become increasingly popular worldwide as an alternative to ankle arthrodesis for surgical treatment of end-stage ankle arthritis. The aim of this epidemiological study, using a national inpatient database in Japan, was to describe the volume, utilization, patient characteristics, and temporal trends regarding these procedures in Japan, and to identify the risk factors associated with perioperative adverse events in TAA. METHODS: This was a population-based, retrospective cohort study. We retrospectively identified 2775 patients in the Diagnosis Procedure Combination database who underwent ankle arthrodesis or TAA for ankle arthritis at 559 hospitals in Japan from 2007 to 2013. Information on sex, age, main diagnosis, use of blood transfusion, duration of anesthesia, length of hospital stay, in-hospital mortality, hospitalization costs, additional procedures after primary surgery, and use of negative pressure wound therapy was extracted. Multivariable logistic regression analysis was performed to analyze the effect of various factors on the incidence of perioperative adverse events in TAA, including additional procedure during hospitalization, negative pressure wound therapy, blood transfusion, and in-hospital death. RESULTS: We identified 465 patients who underwent TAA and 2310 patients who underwent ankle arthrodesis. There was no apparent increase in the proportion of TAAs performed during the survey period. Patients undergoing TAA tended to be older, female, and have rheumatoid arthritis compared with those undergoing ankle arthrodesis. Patients undergoing TAA had shorter length of stay, higher hospitalization costs, and more blood transfusions compared with those undergoing ankle arthrodesis. Lower hospital volume and shorter anesthesia time were associated with higher rates of adverse events after TAA. CONCLUSIONS: Despite an increase in the popularity of TAA internationally, the number of TAAs performed remains low in Japan. Lower hospital volume and anesthesia time were associated with higher rates of perioperative adverse events after TAA. LEVEL OF EVIDENCE: IV, Cross-sectional study.

BACKGROUND: Irreparable peroneus brevis tendon tears are uncommon, and there is scant evidence on which to base operative treatment. Options include tendon transfer, segmental resection with tenodesis to the peroneus longus tendon, and allograft reconstruction. However, the relative effectiveness of the latter 2 procedures in restoring peroneus brevis function has not been established. METHODS: Custom-made strain gage-based tension transducers were implanted into the peroneus longus and brevis tendons near their distal insertions in 10 fresh-frozen cadaver feet. Axial load was applied to the foot, and the peroneal tendons and antagonistic tibialis anterior and posterior tendons were tensioned to 50% and 100% of physiologic load. Distal tendon tension was recorded in this normal condition and after sequential peroneus brevis-to-longus tenodesis and peroneus brevis allograft reconstruction. Measurements were made in 5 foot inversion/eversion and plantarflexion/dorsiflexion positions. RESULTS: Distal peroneus brevis tendon tension after allograft reconstruction significantly exceeded that measured after tenodesis in all tested loading conditions (P ≤ 0.022). With 50% of physiologic load applied, peroneus brevis tension was 1% to 28% of normal (depending on foot position) after tenodesis and 73% to 101% of normal after allograft reconstruction. Under the 100% loading condition, peroneus brevis tension was 6% to 43% of normal after tenodesis and 88% to 99% of normal after reconstruction with allograft. Distal peroneus longus tension remained within 20% of normal under all operative and loading conditions. CONCLUSION: Allograft reconstruction of a peroneus brevis tendon tear in this model substantially restored distal tension when the peroneal tendons and their antagonists were loaded to 50% and 100% of physiologic load. Tenodesis to the peroneus longus tendon did not effectively restore peroneus brevis tension under the tested conditions. CLINICAL RELEVANCE: Because tenodesis was demonstrated to be ineffective for restoration of peroneus brevis function, this procedure may result in an imbalanced foot clinically.

UNLABELLED: The prevalence of hallux varus deformity in rheumatoid arthritis (RA) has been reported to be extremely rare. However, in South Asian Countries, where open-toed shoes are habitual footwear for the majority of people, we have found that hallux varus is a common deformity in patients with RA. This rate of occurrence is much more common than that in published hallux deformities in RA and reinforces the impact of footwear on the development of hallux deformities. In this report, we present 3 illustrative cases of hallux varus developed in patients with RA and review the etiology of hallux varus deformity. LEVELS OF EVIDENCE: Therapeutic, Level IV: Case Study.

BACKGROUND: Intramedullary screw fixation of fifth metatarsal Jones fractures often produces satisfactory results, however, nonunion and refracture rates are not negligible. The low-profile "hook" plate is an alternative fixation method that has been promoted to offer improved rotational control at the fracture site, but this remains to be proven. The purpose of this study was to document biomechanical performance differences between this type of plate and a contemporary solid, dual-pitch intramedullary screw in a cadaveric Jones fracture model. METHODS: Simulated Jones fractures were created in 8 matched pairs of fresh-frozen cadaveric fifth metatarsals. One bone from each pair was stabilized using an intramedullary TriMed Jones Screw and the other using a TriMed Jones Fracture Plate (TriMed, Inc, Santa Clarita, CA). Controlled bending and torsional loads were applied. Bending stiffness and fracture site angulation, as well as torsional stiffness, peak torque, and fracture site rotation were quantified and compared. RESULTS: Intramedullary screw fixation demonstrated greater bending stiffness and less fracture site angulation than plate fixation during plantar-to-dorsal and lateral-to-medial bending. Torsional stiffness of screw-fixed metatarsals exceeded that of plate-fixed bones at initial loading; however, as rotation progressed, the plate resisted torque better than the screw. No difference in peak torque was demonstrable between fixation methods, but it was reached earlier in specimens fixed with screws and later in those fixed with plates as rotation progressed. CONCLUSION: In this cadaveric Jones fracture model, intramedullary screw fixation demonstrated bending stiffness and resistance to early torsional loading that was superior to that offered by plate fixation. CLINICAL RELEVANCE: Although low-profile "hook" plates offer an alternative for fixation of fifth metatarsal Jones fractures, intramedullary screw fixation may provide better resistance to bending and initiation of fracture site rotation. The influence of these mechanical characteristics on fracture healing is unknown, and further clinical investigation is warranted.

Hallux deformities other than hallux valgus, especially those in the sagittal plane, have not yet been elucidated in the feet of patients with rheumatoid arthritis. The objectives of the present study were to classify rheumatoid arthritis hallux deformity in both the horizontal and the sagittal planes and investigate its relationship with flatfoot. Using a cross-sectional study design, we assessed patients with rheumatoid arthritis (527 feet in 274 patients) using radiographs and classified the deformity patterns of the great toes using cluster analysis. Of the 274 patients, the range of motion in the metatarsophalangeal joint was clinically investigated in 44 (16.1%) patients. The great toes could be divided into 5 clusters according to the characteristic configuration as follows: cluster I (normal type), cluster II (hallux valgus type), cluster III (boutonniere type), cluster IV (boutonniere with hallux valgus type), and cluster V (swan-neck type). Radiographic measurements revealed the characteristic deformities of each cluster, including splayed foot for cluster II; flat foot, metatarsal primus elevatus, and plantar displacement of the proximal phalanx for cluster III; and a mixture of these characteristics for cluster IV. Plantar displacement of the proximal phalanx, which was a specific characteristic of the boutonniere deformity, correlated significantly with the decreased dorsiflexion in the metatarsophalangeal joint. Our classification method revealed the relationship of hallux deformity in the sagittal plane to flatfoot and also demonstrated the usefulness of measuring basal phalanx displacement in predicting the range of motion of the metatarsophalangeal joint.

TGF-ß is a multifunctional cytokine that is involved in cell proliferation, differentiation and function. We previously reported an essential role of the TGF-ß -Smad2/3 pathways in RANKL-induced osteoclastogenesis. Using chromatin immunoprecipitation followed by sequencing, we comprehensively identified Smad2/3 target genes in bone marrow macrophages. These genes were enriched in the gene population upregulated by TGF-ß and downregulated by RANKL. Recent studies have revealed that histone modifications, such as trimethylation of histone H3 lysine 4 (H3K4me3) and lysine 27 (H3K27me3), critically regulate key developmental steps. We identified Nedd9 as a Smad2/3 target gene whose histone modification pattern was converted from H3K4me3(+)/H3K4me27(+) to H3K4me3(+)/H3K4me27(-) by TGF-ß. Nedd9 expression was increased by TGF-ß and suppressed by RANKL. Overexpression of Nedd9 partially rescued an inhibitory effect of a TGF-ß inhibitor, while gene silencing of Nedd9 suppressed RANKL-induced osteoclastogenesis. RANKL-induced osteoclastogenesis were reduced and stimulatory effects of TGF-ß on RANKL-induced osteoclastogenesis were partially abrogated in cells from Nedd9-deficient mice although knockout mice did not show abnormal skeletal phenotypes. These results suggest that Nedd9 is a Smad2/3 target gene implicated in RANKL-induced osteoclastogenesis.

The entrapment theory is the most commonly accepted theory concerning the development of interdigital neuroma; it incriminates the deep transverse metatarsal ligament as the major causative factor of the condition. This report presents a patient with interdigital neuroma in the second intermetatarsal space, which was strongly suspected to be caused by the metatarsophalangeal joint instability due to plantar plate injury. Surgical intervention revealed that the neuroma was located more distally and dorsally than the deep transverse metatarsal ligament and was pinched between the adjacent metatarsal heads, suggesting the involvement of the metatarsophalangeal joint instability and chronic trauma as etiologies in this case.

UNLABELLED: Reconstructive surgeries for Charcot foot are challenging due to complicated conditions and comorbidities including poor bone quality, sensory abnormalities, poor vascularity, and immunity impairment. Although various fixation devices, including screws, plates, and external fixators, have been used in the surgical reconstruction of the Charcot midfoot, all of these devices are associated with some disadvantages. This study aims to evaluate the outcome of the Multi-Axial Correction (MAC) monolateral external fixation system for the reconstructive surgery of midfoot Charcot neuroarthropathy. A total of 11 feet with midfoot Charcot arthropathy were treated surgically using the MAC fixation system solely or accompanied with minimal internal fixation. The mean postoperative follow-up was 29 (range = 12-44) months. The mean postoperative timing of the MAC system removal was 8.7 (range = 5-14) weeks. No pin tract infections were observed. All patients went on to successful union and correction of a rocker bottom deformity. No cases resulted in limb amputation. All patients were able to ambulate with custom diabetic shoes and insoles in 9 patients (10 feet) and commercially available shoes in 1 patient (1 foot). This study suggests that the MAC system can be an acceptable, easy option for the surgical treatment of midfoot Charcot arthropathy. LEVEL OF EVIDENCE: Therapeutic, Level IV: Case series.

Significant advancement in pharmacological treatment including biological agents has gradually changed the role and content of surgical treatments for patients with rheumatoid arthritis. The number of joint replacements in the large joints of lower limbs has decreased, while the number of surgeries in the small joints of hand and feet has increased. Favorable disease control by pharmacological treatment has changed the needs of patients for surgeries and expanded the options of operative procedures for surgeons. The changing needs of patients demanding the higher level of quality of life may seek a change in the surgical treatments.

OBJECTIVES: Compensatory hindfoot alignment for deformities at the knee level has been demonstrated in patients with knee osteoarthritis. However, this phenomenon has not been elucidated in patients with rheumatoid arthritis (RA). The aim of this study is to investigate the relationship between knee deformity and hindfoot alignment and the effect of subtalar joint destruction in patients with RA. METHODS: We retrospectively investigated RA patients (110 patients, 205 limbs) using radiographs in the standing anteroposterior knee, standing lateral foot, and hindfoot alignment views. The grade of destruction at the knee and subtalar joints was assigned using Larsen's grading system. The correlation between the femorotibial and tibiocalcaneal angles and the effect of joint destruction on this correlation were analyzed using Pearson's correlation coefficients. RESULTS: There was moderate correlation between the femorotibial and tibiocalcaneal angles in a group of knees with a Larsen grade of ≥ 4 (r = 0.544, p = 0.0239). This correlation was stronger in a group with less damaged subtalar joints with a Larsen grade of ≤ 3 (r = 0.705, p = 0.0049). CONCLUSION: These findings emphasized the importance of examining foot and ankles in patients with RA who undergo total knee arthroplasty.

BACKGROUND: Wound healing problems of the anterior ankle incision are among the most common complications after total ankle arthroplasty, possibly resulting in exposure of the prostheses and infection. The aim of this study was to investigate the role of negative pressure wound therapy (NPWT) in decreasing the rate of wound healing problems after total ankle arthroplasty. METHODS: This is a retrospective cohort study including consecutive patients who underwent total ankle arthroplasty by a single surgeon at a single institution between 2009 and 2013. The incisional negative pressure dressing was applied to all patients who underwent total ankle arthroplasty between 2012 and 2013 with a continuous application of -80 mm Hg negative pressure for 6 days postoperatively. The control group consisted of patients who underwent total ankle arthroplasty between 2009 and 2012 with a conventional nonadherent gauze dressing. Seventy-four patients were involved in this study: 37 in the control group and 37 in the incisional NPWT group. RESULTS: All patients tolerated the incisional NPWT to completion without any dressing failures or skin problems. Both groups showed similar distributions in demographics and perioperative risk factors for wound healing. There were 9 (24%) wound healing problems in the control group and 1 (3%) in the incisional NPWT group. Incisional NPWT was found to reduce wound healing problems with an odds ratio of 0.10 (95% CI, 0.01-0.50; P = .004). CONCLUSIONS: Our study demonstrated that there was a decreased incidence of wound healing problems following total ankle arthroplasty with incisional NPWT dressings. This is the first study evaluating the efficacy of incisional NPWT as an adjunct treatment for wound healing after total ankle arthroplasty. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

We examined the individual and combined effects of teriparatide and anti-RANKL (receptor activator of nuclear factor κB ligand) monoclonal antibody in ovariectomized mice. Three-month-old female C57BL/6 mice were ovariectomized (OVX) or sham operated. Four weeks after OVX, they were assigned to 3 different groups to receive anti-RANKL monoclonal antibody (Ab) alone (5 mg/kg single injection at 4 weeks after OVX, Ab group), teriparatide alone (80 μg/kg daily injection for 4 weeks from 4 weeks after OVX, PTH group), or mAb plus teriparatide (Ab + PTH group). Mice were sacrificed 8 weeks after OVX. Bone mineral density (BMD) was measured at the femur and lumbar spine. Hind limbs were subjected to histological and histomorphometric analysis. Serum osteocalcin and CTX-I levels were measured to investigate the bone turnover. Compared with Ab group, Ab + PTH group showed a significant increase in BMD at distal femur and femoral shaft. Cortical bone volume was significantly increased in PTH and Ab + PTH groups compared with Ab group. Bone turnover in Ab + PTH group was suppressed to the same degree as in Ab group. The number of TRAP-positive multinucleated cells was markedly reduced in Ab and Ab + PTH groups. These results suggest that combined treatment of teriparatide with anti-RANKL antibody has additive effects on BMD in OVX mice compared with individual treatment.

We have previously reported that transforming growth factor β (TGF-β) plays an essential role in receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclastogenesis. However, the detailed underlying molecular mechanisms still remain unclear. Formaldehyde-assisted isolation of regulatory elements (FAIRE) and chromatin immunoprecipitation (ChIP) followed by sequencing (FAIRE-seq and ChIP-seq) analyses indicated the cooperation of Smad2/3 with c-Fos during osteoclastogenesis. Biochemical analysis and immunocytochemical analysis revealed that physical interaction between Smad2/3 and c-Fos is required for their nuclear translocation. The gene expression of nuclear factor of activated T-cells, cytoplasmic 1 (Nfatc1), a key regulator of osteoclastogenesis, was regulated by RANKL and TGF-β, and c-Fos binding to open chromatin sites was suppressed by inhibition of TGF-β signaling by SB431542. Conversely, Smad2/3 binding to Nfatc1 was impaired by c-Fos deficiency. These results suggest that TGF-β regulates RANKL-induced osteoclastogenesis through reciprocal cooperation between Smad2/3 and c-Fos.

Advances in implant technology have made total ankle arthroplasty an increasingly popular alternative to arthrodesis for the management of ankle arthritis. However, a frequent complication of the procedure is nerve impingement related to either to heterotrophic bone growth or the prosthesis itself. Successful resolution of this complication presents a challenge to clinicians. We present a case of lateral impingement following total ankle arthroplasty that was successfully treated using a partial transmalleolar approach to effect a partial osteotomy of the lateral malleolus and create a fragment attached to the anterior talofibular and calcaneofibular ligaments. This approach provides a good operative field in the lateral gutter with minimal soft tissue impairment. It also facilitates curettage, and resolution of tissue impingement. The osteotomy site healed fully by 3 months postoperative, and the pain around the lateral malleolus resolved. Furthermore, the patient's score on the Japanese Society for Surgery of the Foot Ankle/Hindfoot Scale improved from 33 preoperatively to 82 at 6 months postoperative.

Functional disability is a major concern in patients with rheumatoid arthritis (RA). This retrospective study investigated the risk factors for vertebral fractures (VFs) in postmenopausal RA patients and determined the impact of VFs on functional status. Data from a cohort of 200 postmenopausal RA patients in a single hospital registry were analyzed. Demographic and clinical data, imaging data from spine radiographs, and bone mineral density (BMD) data were collected from the patients at baseline and at the final visit (a mean of 2.9 years after the first visit). Risk factors for incident VFs and their impact on the modified health assessment questionnaire (mHAQ) were analyzed. Twenty-eight patients (14%) developed new VFs (NVFs). Logistic regression analysis adjusted for age, BMI, and disease duration revealed that daily dose of prednisolone, femoral neck BMD, use of active vitamin D3, and use of a bisphosphonate at baseline were factors associated with NVF, with odds ratios (95% confidence interval) of 1.27 (1.05-1.54), 0.94 (0.91-0.97), 0.34 (0.13-0.89), and 0.31 (0.12-0.82), respectively. Patients with NVF exhibited worse mHAQ scores and a greater increase in mHAQ scores from baseline compared with those without NVF. In conclusion, incident VFs were associated with reduced functional status in postmenopausal patients with RA. It is important to prevent VFs to maintain the functional status of RA patients.

OBJECTIVE: Foot and ankle deformities greatly affect the quality of life of rheumatoid arthritis (RA) patients. The aim of this study was to elucidate the pattern of destruction of the RA foot and its impact on patients. METHODS: We cross-sectionally investigated RA patients (274 patients and 542 feet) using radiographs. The grade of joint destruction was assigned using Larsen's grading system for 12 joints in the foot and ankle. Cluster analysis was performed using the K-means method to classify the pattern of joint destruction. Of the 274 patients evaluated radiographically, 212 were assessed for functional disability using questionnaires. RESULTS: Cluster analysis revealed that 542 feet were divided into 5 clusters, named according to the characteristic distribution of joint destruction: cluster I (normal type), cluster II (forefoot type), cluster III (midfoot type), cluster IV (mid-hindfoot type), and cluster V (combined type). Radiographic measurements revealed the characteristic deformities of each cluster: splay foot for cluster II, flat foot for cluster III, hindfoot malalignment for cluster IV, and mixtures of these characteristics for cluster V. A distribution map of each cluster based on disease duration revealed that cluster III peaked in cases of 5-10-year disease duration and subsequently decreased, followed by a gradual increase of cluster IV and cluster V. Cluster IV and cluster V showed significant changes in functional disability compared to cluster III. CONCLUSION: This report is the first to reveal the pattern of RA foot deformities and their impact on patients using statistical measures in a large series.

Signal transducer and activator of transcription 5 (Stat5) is essential for cytokine-regulated processes such as proliferation, differentiation, and survival in hematopoietic cells. To investigate the role of Stat5 in osteoclasts, we generated mice with an osteoclast-specific conditional deletion of Stat5 (Stat5 conditional knockout [cKO] mice) and analyzed their bone phenotype. Stat5 cKO mice exhibited osteoporosis caused by an increased bone-resorbing activity of osteoclasts. The activity of mitogen-activated protein kinases (MAPKs), in particular extracellular signal-related kinase, was increased in Stat5 cKO osteoclasts, whereas the expression of the MAPK phosphatases dual specificity phosphatase 1 (Dusp1) and Dusp2 was significantly decreased. Interleukin-3 (IL-3) stimulated the phosphorylation and nuclear translocation of Stat5 in osteoclasts, and Stat5 expression was up-regulated in response to receptor activator of nuclear factor κB ligand (RANKL). The results suggest that Stat5 negatively regulates the bone-resorbing function of osteoclasts by promoting Dusp1 and Dusp2 expression, and IL-3 promotes Stat5 activation in osteoclasts.

We investigated the midterm results of resection arthroplasty of all 5 metatarsal heads in patients with rheumatoid arthritis and forefoot deformity and analyzed the factors that affect patient satisfaction levels. Of 64 patients (1 male, 63 females), 107 feet were treated with resection arthroplasty for forefoot deformity at our hospital from January 1992 to December 2005. The mean follow-up period was 5.8 ± 3.1 years, with all patients having at least 1 year of follow-up. Of the 64 patients, 75% were satisfied with the surgery. The mean score for the postoperative Japanese Society for Surgery of the Foot lesser metatarsophalangeal-interphalangeal scale was 75.0 ± 15.8 points. Multivariate logistic regression analysis showed that patient-reported dissatisfaction was significantly associated with the recurrence of hammer toe deformity (odds ratio 2.66, 95% confidence interval 1.07 to 6.97), shortening of the resection arthroplasty space (odds ratio 0.85 for a 1-unit increase, 95% confidence interval 0.74 to 0.96), and the recurrence of hallux valgus (odds ratio 1.04 for a 1-unit increase, 95% confidence interval 1.00 to 1.09) during the postoperative period. From our results, interventions to prevent recurrence of hammer toe deformity, especially in toes with preoperative metatarsophalangeal joint dislocations, have been shown to be important in preventing complications and patient dissatisfaction after resection arthroplasty.

The purpose of this study was to compare the biomechanical properties of two common forms of prophylactic fixation of the medial malleolus during total ankle arthroplasty (TAA). Ten matched pairs of cadaveric lower extremities were fixed with a single cannulated cortical screw or a one-third tubular plate after preparation for TAA. Ten unmatched single cadaver lower extremities were used as the control. A transverse load was applied to the medial malleolus. Bone mineral density, peak loads at fracture, and fracture pattern were noted. There was no statistically significant difference in peak load to failure between either fixation cohorts or between the fixation cohort and the control cohort. There was a moderate positive correlation between bone mineral density and peak load for all three experimental groups. The peak load was significantly (p = .035) increased in male cadavers. Fractures occurred almost exclusively at the apex of the tibial and malleolar cuts with a vertical fracture pattern.

Liposomal bupivacaine, a slow-releasing form of bupivacaine, is proving to be effective and safe for postsurgical pain management. It can provide great benefit and patient satisfaction because of its long-duration local analgesia by a single infiltration for up to 72 hours. A technical tip and application considerations of liposomal bupivacaine in total ankle arthroplasties are described.

PURPOSE: Arthrodesis of distal interphalangeal (DIP) and thumb interphalangeal (IP) joints is a well-established procedure for the treatment of pain, deformity, and instability associated with arthritis and traumatic conditions. Fixation with various headless compression screws has become increasingly common and with favorable outcomes. However, there are still characteristic complications, such as hardware prominence with the distal end of the screw incompletely buried in the distal phalanx. The purpose of this study was to review the outcomes and complications associated with the arthrodesis of DIP and thumb IP joints using the Reverse Fix Nail (Tact Medical, Inc., Tokyo, Japan), a headless compression screw designed for DIP and thumb IP joint arthrodesis. METHODS: We retrospectively reviewed 89 cases involving 60 patients, in which arthrodesis with the Reverse Fix Nail was performed for DIP and thumb IP joints. We referenced medical charts, radiographs, and operative records to investigate the complications and postoperative periods to bone union. RESULTS: Of the 89 consecutive cases, 86 (97%) achieved bone union. Complications included 1 case of prominent hardware and 3 cases of nonunion (1 was asymptomatic and the other 2 were symptomatic, requiring secondary surgery). CONCLUSIONS: The Reverse Fix Nail is a favorable implant for DIP joint or thumb IP joint arthrodesis with a comparable bone union rate and lower risk of hardware prominence than other implants.

We investigated the role of protein kinase B (Akt), a downstream effector of phosphatidylinositol 3-kinase, in bone-resorbing activity of mature osteoclasts. Treatment with a specific Akt inhibitor disrupted sealing zone formation and decreased the bone-resorbing activity of osteoclasts. The normal microtubule structures were lost and the Akt inhibitor reduced the amount of acetylated tubulin, which reflects stabilized microtubules, whereas forced Akt activation by adenovirus vectors resulted in the opposite effect. Forced Akt activation increased the binding of the microtubule-associated protein adenomatous polyposis coli (APC), the APC-binding protein end-binding protein 1 (EB1) and dynactin, a dynein activator complex, with microtubules. Depletion of Akt1 and Akt2 resulted in a disconnection of APC/EB1 and a decrease in bone-resorbing activity along with reduced sealing zone formation, both of which were recovered upon the addition of LiCl, a glycogen synthase kinase-3β (GSK-3β) inhibitor. The Akt1 and Akt2 double-knockout mice exhibited osteosclerosis due to reduced bone resorption. These findings indicate that Akt controls the bone-resorbing activity of osteoclasts by stabilizing microtubules via a regulation of the binding of microtubule associated proteins.

Tumor necrosis factor (TNF) antagonists have brought about a significant advancement in treatment for autoimmune diseases such as rheumatoid arthritis (RA) and Crohn's disease; however, they are accompanied with a risk of severe adverse effects. We report the case of a 68-year-old female with a 33-year history of RA that developed multiple sclerosis (MS) during adalimumab (ADM) treatment at 22 months after the initial administration. Her first neurological symptom was mild dizziness, which progressed to severe dizziness with gait disturbance within 2 weeks. Fortunately, when she had this neurological disorder, ADM treatment was being transiently stopped because she was in the perioperative period. Repeated magnetic resonance imaging examinations revealed multiple demyelinating lesions in her brain, leading to the diagnosis of MS. The patient completely recovered spontaneously from the symptoms in several days. A review of the literature revealed another 15 cases of MS associated with anti-TNF-α treatment, emphasizing the importance of detecting neurological symptoms and discontinuing the anti-TNF-α therapy.

OBJECTIVE: Nitrogen-containing bisphosphonates are one of the most successful therapeutics for osteoporosis. The aim of this study was to elucidate the functional mechanism of one of the typical nitrogen-containing bisphosphonates, risedronate. METHODS: Osteoclasts generated from murine bone marrow macrophages were treated with risedronate in vitro, and its effects on apoptosis and bone-resorbing activity were examined. The mechanism of action of risedronate was examined by gene induction of constitutively active Akt-1 and constitutively active MEK-1, and by gene deletion of Bim. Bim(-/-) mice, in which osteoclasts were resistant to apoptosis, were treated with risedronate and analyzed radiographically, biochemically, and histologically. RESULTS: Risedronate induced osteoclast apoptosis through the mitochondria-dependent pathway with an increased expression of Bim, and the proapoptotic effect of risedronate was suppressed by Bim deletion and constitutively active MEK-1 introduction. In contrast, the risedronate-induced suppression of bone resorption was completely reversed by inducing constitutively active Akt-1, but not by Bim deletion or constitutively active MEK-1 introduction. These results suggested that apoptosis and bone-resorbing activity of osteoclasts were regulated through the ERK/Bim axis and the Akt pathway, respectively, both of which were suppressed by risedronate. Although osteoclast apoptosis in response to risedronate administration was suppressed in the Bim(-/-) mice, risedronate treatment increased bone mineral density in Bim(-/-) mice at a level equivalent to that in wild-type mice. CONCLUSION: Our findings indicate that the antiresorptive effect of risedronate in vivo is mainly mediated by the suppression of the bone-resorbing activity of osteoclasts and not by the induction of osteoclast apoptosis.

Previous studies have shown that transforming growth factor β (TGF-β) promotes receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclastogenesis. However, the underlying molecular mechanisms have not been elucidated. When TGF-β signals were blocked either by a specific inhibitor of TGF-β type 1 receptor kinase activity, SB431542, or by introducing a dominant-negative mutant of TGF-β type 2 receptor, RANKL-induced osteoclastogenesis was almost completely suppressed. Blockade of Smad signaling by overexpression of Smad7 or c-Ski markedly suppressed RANKL-induced osteoclastogenesis, and retroviral induction of an activated mutant of Smad2 or Smad3 reversed the inhibitory effect of SB431542. Immunoprecipitation analysis revealed that Smad2/3 directly associates with the TRAF6-TAB1-TAK1 molecular complex, which is generated in response to RANKL stimulation and plays an essential role in osteoclast differentiation. TRAF6-TAB1-TAK1 complex formation was not observed when TGF-β signaling was blocked. Analysis using deletion mutants revealed that the MH2 domain of Smad3 is necessary for TRAF6-TAB1-TAK1 complex formation, downstream signal transduction, and osteoclast formation. In addition, gene silencing of Smad3 in osteoclast precursors markedly suppressed RANKL-induced osteoclast differentiation. In summary, TGF-β is indispensable in RANKL-induced osteoclastogenesis, and the binding of Smad3 to the TRAF6-TAB1-TAK1 complex is crucial for RANKL-induced osteoclastogenic signaling.

The antiapoptotic molecule Bcl-2 inhibits apoptosis by preventing cytochrome c release from mitochondria. Although several studies have indicated the importance of Bcl-2 in maintaining skeletal integrity, the detailed cellular and molecular mechanisms remain elusive. Since Bcl-2(-/-) mice die before six weeks of age on account of renal failure and cannot be compared to adult wild-type mice, we generated Bcl-2(-/-)Bim(+/-) mice, in which a single Bim allele was inactivated, and compared them with their Bcl-2(+/-)Bim(+/-) littermates. Bcl-2(-/-)Bim(+/-) mice grew normally, but exhibited decreased bone mass compared to Bcl-2(+/-)Bim(+/-) mice, mainly due to impaired osteoblast function. Interestingly, the anabolic effect of parathyroid hormone (PTH) was not observed in Bcl-2(-/-)Bim(+/-) mice. This data demonstrates that Bcl-2 is indispensable for the anabolic activity of PTH in bone.

The anti-apoptotic molecule Bcl-2 inhibits apoptosis by preventing cytochrome c release from mitochondria. Although several studies have indicated the importance of Bcl-2 in maintaining skeletal integrity, the detailed cellular and molecular mechanisms remain elusive. Bcl-2(-/-) mice are growth-retarded and exhibit increased bone volume of the primary spongiosa, mainly due to the decreased number and dysfunction of osteoclasts. Osteoblast function is also impaired in Bcl-2(-/-) mice. Ex vivo studies on osteoblasts and osteoclasts showed that Bcl-2 promoted the differentiation, activation, and survival of both cell types. Because Bcl-2(-/-) mice die before 6 weeks of age due to renal failure and cannot be compared with adult wild type mice, we generated Bcl-2(-/-)Bim(+/-) mice, in which a single Bim allele was inactivated, and compared them with their Bcl-2(+/-)Bim(+/-) littermates. Loss of a single Bim allele restored normal osteoclast function in Bcl-2(-/-) mice but did not restore the impaired function of osteoblasts, and the mice exhibited osteopenia. These data demonstrate that Bcl-2 promotes the differentiation, activity, and survival of both osteoblasts and osteoclasts. The balance between Bcl-2 and Bim regulates osteoclast apoptosis and function, whereas other pro-apoptotic members are important for osteoblasts.

The B cell lymphoma 2 (Bcl-2) family member Bcl-xL has a well-characterized antiapoptotic function in lymphoid cells. However, its functions in other cells--including osteoclasts, which are of hematopoietic origin--and other cellular processes remain unknown. Here we report an unexpected function of Bcl-xL in attenuating the bone-resorbing activity of osteoclasts in mice. To investigate the role of Bcl-xL in osteoclasts, we generated mice with osteoclast-specific conditional deletion of Bcl-x (referred to herein as Bcl-x cKO mice) by mating Bcl-xfl/fl mice with mice in which the gene encoding the Cre recombinase has been knocked into the cathepsin K locus and specifically expressed in mature osteoclasts. Although the Bcl-x cKO mice grew normally with no apparent morphological abnormalities, they developed substantial osteopenia at 1 year of age, which was caused by increased bone resorption. Bcl-x deficiency increased the bone-resorbing activity of osteoclasts despite their high susceptibility to apoptosis, whereas Bcl-xL overexpression produced the opposite effect. In addition, Bcl-x cKO osteoclasts displayed increased c-Src activity, which was linked to increased levels of vitronectin and fibronectin expression. These results suggest that Bcl-xL attenuates osteoclastic bone-resorbing activity through the decreased production of ECM proteins, such as vitronectin and fibronectin, and thus provide evidence for what we believe to be a novel cellular function of Bcl-xL.

A 39-year-old man with rheumatoid arthritis developed femoral neuropathy secondary to iliopsoas bursitis. The adjacent hip joint was severely damaged. Magnetic resonance imaging showed enlargement and inflammation of the psoas muscle at the same side of iliopsoas bursitis. Iliopsoas bursitis and abnormal findings of the psoas muscle disappeared while the symptoms improved.