Cigarette smoke impairs the hematopoietic supportive property of mesenchymal stem cells via the production of reactive oxygen species and NLRP3 activation.

BACKGROUND: Mesenchymal stem cells (MSCs) play important roles in tissue homeostasis by providing a supportive microenvironmental niche for the hematopoietic system. Cigarette smoking induces systemic abnormalities, including an impeded recovery process after hematopoietic stem cell transplantation. However, the role of cigarette smoking-mediated alterations in MSC niche function have not been investigated. METHODS: In the present study, we investigated whether exposure to cigarette smoking extract (CSE) disrupts the hematopoietic niche function of MSCs, and pathways impacted. To investigate the effects on bone marrow (BM)-derived MSCs and support of hematopoietic stem and progenitor cells (HSPCs), mice were repeatedly infused with the CSE named 3R4F, and hematopoietic stem and progenitor cells (HSPCs) supporting function was determined. The impact of 3R4F on MSCs at cellular level were screened by bulk-RNA sequencing and subsequently validated through qRT-PCR. Specific inhibitors were treated to verify the ROS or NLRP3-specific effects, and the cells were then transplanted into the animal model or subjected to coculture with HSPCs. RESULTS: Both direct ex vivo and systemic in vivo MSC exposure to 3R4F resulted in impaired engraftment in a humanized mouse model. Furthermore, transcriptomic profile analysis showed significantly upregulated signaling pathways related to reactive oxygen species (ROS), inflammation, and aging in 3R4F-treated MSCs. Notably, ingenuity pathway analysis revealed the activation of NLRP3 inflammasome signaling pathway in 3R4F-treated MSCs, and pretreatment with the NLRP3 inhibitor MCC950 rescued the HSPC-supporting ability of 3R4F-treated MSCs. CONCLUSION: In conclusion, these findings indicate that exposure to CSE reduces HSPCs supportive function of MSCs by inducing robust ROS production and subsequent NLRP3 activation.

Contrast-enhanced MRI findings of patients with acute Bell palsy within 7 days of symptom onset: A retrospective study.

The brain magnetic resonance imaging (MRI) findings seen in patients with Bell palsy are abnormal contrast enhancement of affected facial nerves. Previous studies were conducted on a few patients, mainly those who had experienced palsy for several weeks. This study investigated the diagnostic usefulness of MRI by examining MRI findings of acute Bell palsy (within 7 days of symptom onset) in a large cohort. Among the patients with Bell palsy (idiopathic unilateral facial palsy) who visited the hospital, 123 patients who underwent contrast-enhanced MRI of the internal auditory canal within 7 days of symptom onset were reviewed retrospectively. MRI examination results were investigated along with the patient's clinical symptoms and electrodiagnostic test results. Based on the MRI results, the frequency of abnormal contrast enhancement and contrast-enhanced areas were investigated. Of the 123 patients, 13 (11%) had normal brain MRI results, and 110 (89%) had abnormal findings. The frequency of abnormal contrast enhancement was not significantly associated with test timing (P = .56). Of the 110 patients with abnormal findings, 65 (59%) showed contrast enhancement in the labyrinthine segment and 36 (33%) in both the labyrinthine segment and geniculate ganglion. Most patients with Bell palsy who are in the acute phase showed abnormal contrast enhancement in their facial nerves, and similar findings were even observed in the examination conducted on the day of symptom onset. Brain MRI helps in the diagnosis of acute Bell palsy.

Effect of Self-treatment of Recurrent Benign Paroxysmal Positional Vertigo: A Randomized Clinical Trial.

Importance: Benign paroxysmal positional vertigo (BPPV) is the most common cause of vertigo with frequent recurrences. Objective: To determine the efficacy of a web-based diagnosis and treatment of BPPV when it recurs in patients with confirmed and treated BPPV. Design, Setting, and Participants: This randomized, controlled, parallel-group, double-blind trial took place in multiple referral-based university hospitals in South Korea between July 2017 and February 2020. Of 728 patients (age ≥20 years) with diagnosed and treated BPPV, 585 were enrolled after excluding 143 who declined participation, could not use the internet, or had spinal problems, multicanal BPPV, or cognitive dysfunction. Patients were followed up for recurrence at least for 2 years until February 2022. Interventions: Patients were randomly assigned (1:1) to the treatment or control group. The patients in the treatment group completed a questionnaire for diagnosis and received a video clip for self-administration of canalith repositioning maneuver (CRM) according to the type of BPPV diagnosed when they experienced positional vertigo again. Patients in the control group received a video clip for self-administration of CRM according to the type of BPPV that had been diagnosed on enrollment. Main Outcomes and Measures: The primary outcome was self-reported resolution of positional vertigo post-CRM. Secondary outcomes included difficulties and requirement for assistance when using the program and any falls or other adverse events related to CRM. The primary outcome was analyzed using both intention-to-treat and per-protocol methods. Results: Of 585 patients enrolled, 292 were randomized to the treatment group (mean [SD] age, 60.3 [12.8] years, 37 [64%] women) and 293 were randomized to the control group (mean [SD] age, 61.1 [13.2] years; 50 [71%] women). Overall, 128 (21.9%) had recurrence (58 in the treatment group and 70 in the control group), and 109 (85.2%) successfully used the web-based system. In the intention-to-treat analysis, 42 of 58 individuals (72.4%) in the treatment group and 30 of 70 individuals (42.9%) in the control group reported vertigo resolution (χ2 test: 95% CI, 0.13-0.46; P < .001). Conclusions and Relevance: This trial proved the efficacy of a web-based system for the diagnosis and treatment of recurrent BPPV. Use of this system may play an important role in telemedicine for vestibular disorders. Trial Registration: Clinical Research Information Service Identifier: KCT0002364.

Adaptive Discount Factor for Deep Reinforcement Learning in Continuing Tasks with Uncertainty.

Reinforcement learning (RL) trains an agent by maximizing the sum of a discounted reward. Since the discount factor has a critical effect on the learning performance of the RL agent, it is important to choose the discount factor properly. When uncertainties are involved in the training, the learning performance with a constant discount factor can be limited. For the purpose of obtaining acceptable learning performance consistently, this paper proposes an adaptive rule for the discount factor based on the advantage function. Additionally, how to use the advantage function in both on-policy and off-policy algorithms is presented. To demonstrate the performance of the proposed adaptive rule, it is applied to PPO (Proximal Policy Optimization) for Tetris in order to validate the on-policy case, and to SAC (Soft Actor-Critic) for the motion planning of a robot manipulator to validate the off-policy case. In both cases, the proposed method results in a better or similar performance compared with cases using the best constant discount factors found by exhaustive search. Hence, the proposed adaptive discount factor automatically finds a discount factor that leads to comparable training performance, and that can be applied to representative deep reinforcement learning problems.

Sodium Tetradecyl Sulphate Sclerotherapy for Lateral Malleolar Bursitis of the Ankle.

Background: The aim of this study was to evaluate clinical outcomes of sodium tetradecyl sulphate (STS) sclerotherapy for conservative treatment of lateral malleolar bursitis of the ankle. Methods: We reviewed data from 20 consecutive patients (20 ankles) who underwent STS sclerotherapy between August 2018 and June 2019. After aspiration of fluid from the lateral malleolar bursal sac, 2 mL (20 mg) STS was injected into the sac. Clinical outcomes and side effects and complications were evaluated at 2 weeks, 3 months, 1 year, and 2 years after sclerotherapy. Responses to treatment were assessed according to degree of fluctuation, shrinkage of the bursal sac, and soft-tissue swelling. The 36-item short form survey (SF-36) was completed for each patient before and after therapy. Results: Complete response was observed in 17 patients (85%), and partial response was observed in 3 patients (15%) after STS sclerotherapy. SF-36 physical component scores improved from 62.2 (interquartile range, 5.2) before therapy to 70.0 (interquartile range, 7.9) at last follow-up (p < 0.05). One patient (5%) experienced transient hyperpigmentation at the injection site. No major complications occurred. Conclusions: STS sclerotherapy was an effective and safe treatment for patients with lateral malleolar bursitis of the ankle.

Long-Term Clinical Outcomes and Implant Survivorship of 151 Total Ankle Arthroplasties Using the HINTEGRA Prosthesis: A Minimum 10-Year Follow-up.

BACKGROUND: Few studies have investigated long-term clinical outcomes of a mobile-bearing total ankle arthroplasty (TAA) system. This study analyzed long-term outcomes of TAA using the HINTEGRA prosthesis at a single, non-developer center. METHODS: Primary TAAs were performed on 213 ankles in 194 patients, and 151 consecutive ankles [71%] in 136 patients with a minimum follow-up of 10 years after the primary TAA were included in this study. Clinical results were assessed using a visual analog scale (VAS) pain score, the American Orthopaedic Foot & Ankle Society (AOFAS) Ankle-Hindfoot Scale score, the Ankle Osteoarthritis Scale (AOS) pain and disability subscores, and ankle range of motion. Prosthesis survivorship, reoperations, and risk factors were also evaluated. RESULTS: The mean follow-up was 135.5 months (range, 120.0 to 204.0 months). All clinical scores and ankle range of motion improved significantly from preoperatively to 2 years, 4 to 6 years, and ≥10 years after TAA (p < 0.001). A total of 43 ankles (28.5%) required revision procedures, with the most common reason being periprosthetic osteolysis (32 ankles [21.2%]). The overall implant survivorship was 93.5% in Kaplan-Meier survival analysis at the mean follow-up of 11.3 years after the TAA. CONCLUSIONS: TAA using the HINTEGRA prosthesis with careful follow-up observation and appropriate adjunct procedures for the treatment of end-stage ankle arthritis produced satisfactory clinical results, which were maintained at a follow-up of ≥10 years, and resulted in 93.5% of implant survivorship. LEVEL OF EVIDENCE: Prognostic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Association between outdoor temperature and achilles tendon repair: A 14-years nationwide population-based cohort study.

The incidence of achilles tendon rupture varies by gender, age, and seasonal variation. However, there has been no study as yet linking achilles tendon rupture to daily fluctuations in outdoor temperature. The purpose of this study was to investigate the association between outdoor temperature and achilles tendon rupture using a Korea Meteorological Administration database and a Korean National Health Insurance Service-National Sample Cohort database. Between 2002 and 2015, all instances of achilles tendon repair were retrieved from the National Health Insurance Service-National Sample Cohort database to examine sociodemographic factors, specifically sex, age, residential area, and income level. Minimum age requirement was 20 years. Outdoor temperatures recorded at 16 observation points in South Korea were also acquired from the Korea Meteorological Administration data center for analysis. Overall, 850 (0.119%) of 713,456 individuals in the National Health Insurance Service-National Sample Cohort database underwent achilles tendon repair between 2002 and 2015. Yearly procedural totals increased with advancing age, peaking at ages 30-39 years (14.6 per 100,000 persons) and declining thereafter. Minimum, median, and maximum outdoor temperatures were associated with achilles tendon repair (p<0.05), as did household income. In multivariate logistic regression analysis, outdoor temperatures, sex, age, and household income emerged as factors significantly associated with achilles tendon repair. Outcomes of this study confirm an association between incidence of achilles tendon repair and outdoor temperature, the latter denoting a novel index and likely surrogate measure of vigorous physical activity afforded by warmer weather.

Diesel Exhaust Particles Impair Therapeutic Effect of Human Wharton's Jelly-Derived Mesenchymal Stem Cells against Experimental Colitis through ROS/ERK/cFos Signaling Pathway.

Background and Objectives: Epidemiological investigations have shown positive correlations between increased diesel exhaust particles (DEP) in ambient air and adverse health outcomes. DEP are the major constituent of particulate atmospheric pollution and have been shown to induce proinflammatory responses both in the lung and systemically. Here, we report the effects of DEP exposure on the properties of human Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs), including stemness, regeneration, and immunomodulation. Methods and Results: Non-apoptotic concentrations of DEP (10 µg/ml) inhibited the migration and osteogenic differentiation capacity of WJ-MSCs. Gene expression profiling showed that DEP increased intracellular reactive oxygen species (ROS) and expression of pro-inflammatory and metabolic-process-related genes including cFos. Furthermore, WJ-MSCs cultured with DEP showed impaired suppression of T cell proliferation that was reversed by inhibition of ROS or knockdown of cFos. ERK inhibition assay revealed that DEP-induced ROS regulated cFos through activation of ERK but not NF-κB signaling. Overall, low concentrations of DEP (10 µg/ml) significantly suppressed the stemness and immunomodulatory properties of WJ-MSCs through ROS/ERK/cFos signaling pathways. Furthermore, WJ-MSCs cultured with DEP impaired the therapeutic effect of WJ-MSCs in experimental colitis mice, but was partly reversed by inhibition of ROS. Conclusions: Taken together, these results indicate that exposure to DEP enhances the expression of pro-inflammatory cytokines and immune responses through a mechanism involving the ROS/ERK/cFos pathway in WJ-MSCs, and that DEP-induced ROS damage impairs the therapeutic effect of WJ-MSCs in colitis. Our results suggest that modulation of ROS/ERK/cFos signaling pathways in WJ-MSCs might be a novel therapeutic strategy for DEP-induced diseases.

Bone Marrow Stimulation for Osteochondral Lesions of the Talus: Are Clinical Outcomes Maintained 10 Years Later?

BACKGROUND: Arthroscopic bone marrow stimulation (BMS) is considered the first-line treatment for osteochondral lesions of the talus (OLTs). However, the long-term stability of the clinical success of BMS remains unclear. PURPOSE: To investigate the long-term clinical outcomes among patients who underwent BMS for OLT and to identify prognostic factors for the need for revision surgery. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A retrospective analysis was performed on 202 ankles (189 patients) that were treated with BMS for OLT and had a minimum follow-up of 10 years. The visual analog scale for pain, American Orthopaedic Foot & Ankle Society ankle-hindfoot score, and the Foot and Ankle Outcome Score (FAOS) were assessed by repeated measures analysis of variance. Prognostic factors associated with revision surgery were evaluated with Cox proportional hazard regression models and log-rank tests. RESULTS: The mean lesion size was 105.32 mm2 (range, 19.75-322.79); 42 ankles (20.8%) had large lesions (≥150 mm2). The mean visual analog scale for pain improved from 7.11 ± 1.73 (mean ± SD) preoperatively to 1.44 ± 1.52, 1.46 ± 1.57, and 1.99 ± 1.67 at 1, 3 to 6, and ≥10 years, respectively, after BMS (P < .001). The mean ankle-hindfoot score also improved, from 58.22 ± 13.57 preoperatively to 86.88 ± 10.61, 86.17 ± 10.23, and 82.76 ± 11.65 at 1, 3 to 6, and ≥10 years after BMS (P < .001). The FAOS at the final follow-up was 82.97 ± 13.95 for pain, 81.81 ± 14.64 for symptoms, 83.49 ± 11.04 for activities of daily living, 79.34 ± 11.61 for sports, and 78.71 ± 12.42 for quality of life. Twelve ankles underwent revision surgery after a mean 53.5 months. Significant prognostic factors associated with revision surgery were the size of the lesion (preoperative magnetic resonance imaging measurement ≥150 mm2; P = .014) and obesity (body mass index ≥25; P = .009). CONCLUSION: BMS for OLT yields satisfactory clinical outcomes at a mean follow-up of 13.9 years. The success of the surgery may depend on the lesion size and body mass index of the patient.

An alternative mechanism of crossed vertical gaze palsy in unilateral mesodiencephalic infarction.

Crossed vertical gaze palsy refers to a rare combination of elevation paresis in one eye and depression palsy in the fellow eye. It was once reported in a patient with unilateral infarction involving the mesodiencephalic junction, and was ascribed to selective disruption of the fibers projecting from the rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF) to the oculomotor nuclear complex. Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a rare cause of ophthalmoplegia and crossed vertical gaze palsy has not been described in this disorder. Our patient with a circumscribed acute infarction involving the left mesodiencephalic junction due to CADASIL showed both upward and downward gaze palsy in both eyes, but more marked depression paresis in the ipsilesional eye and more conspicuous elevation deficit in the contralesional eye, which was consistent with crossed vertical gaze palsy. We provide alternate explanation for this rare phenotype of vertical gaze palsy. Selective disruption of riMLF fibers may cause crossed vertical gaze palsy in unilateral mesodiencephalic lesion.

Path Planning for Multi-Arm Manipulators Using Deep Reinforcement Learning: Soft Actor-Critic with Hindsight Experience Replay.

Since path planning for multi-arm manipulators is a complicated high-dimensional problem, effective and fast path generation is not easy for the arbitrarily given start and goal locations of the end effector. Especially, when it comes to deep reinforcement learning-based path planning, high-dimensionality makes it difficult for existing reinforcement learning-based methods to have efficient exploration which is crucial for successful training. The recently proposed soft actor-critic (SAC) is well known to have good exploration ability due to the use of the entropy term in the objective function. Motivated by this, in this paper, a SAC-based path planning algorithm is proposed. The hindsight experience replay (HER) is also employed for sample efficiency and configuration space augmentation is used in order to deal with complicated configuration space of the multi-arms. To show the effectiveness of the proposed algorithm, both simulation and experiment results are given. By comparing with existing results, it is demonstrated that the proposed method outperforms the existing results.

Prevention of benign paroxysmal positional vertigo with vitamin D supplementation: A randomized trial.

OBJECTIVE: To assess the effect of vitamin D and calcium supplementation in preventing recurrences of benign paroxysmal positional vertigo (BPPV). METHODS: We performed an investigator-initiated, blinded-outcome assessor, parallel, multicenter, randomized controlled trial in 8 hospitals between December 2013 and May 2017. Patients with confirmed BPPV were randomly assigned to the intervention (n = 518) or the observation (n = 532) group after successful treatment with canalith repositioning maneuvers. The primary outcome was the annual recurrence rate (ARR). Patients in the intervention group had taken vitamin D 400 IU and 500 mg of calcium carbonate twice a day for 1 year when serum vitamin D level was lower than 20 ng/mL. Patients in the observation group were assigned to follow-ups without further vitamin D evaluation or supplementation. RESULTS: The intervention group showed a reduction in the ARR (0.83 [95% confidence interval (CI), 0.74-0.92] vs 1.10 [95% CI, 1.00-1.19] recurrences per 1 person-year) with an incidence rate ratio of 0.76 (95% CI, 0.66-0.87, p < 0.001) and an absolute rate ratio of -0.27 (-0.40 to -0.14) from intention-to-treat analysis. The number needed to treat was 3.70 (95% CI, 2.50-7.14). The proportion of patients with recurrence was also lower in the intervention than in the observation group (37.8 vs 46.7%, p = 0.005). CONCLUSIONS: Supplementation of vitamin D and calcium may be considered in patients with frequent attacks of BPPV, especially when serum vitamin D is subnormal. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that for patients with BPPV, vitamin D and calcium supplementation reduces recurrences of BPPV.

Collagen dressing in the treatment of diabetic foot ulcer: A prospective, randomized, placebo-controlled, single-center study.

AIMS: Because collagen is fundamental to wound healing and skin formation, collagen-containing dressing materials might be beneficial in treating diabetic foot ulcers (DFU), but supporting evidence is needed. Here, we examined the effectiveness and safety of collagen dressing material in DFU treatment. METHODS: This prospective, randomized, placebo-controlled, single-center study included patients with type 1 or 2 diabetes and palpable foot pulse who had Wagner grade 1 or 2 ulcers ≥1.0 cm2 with no signs of healing for ≥6 weeks. Patients were treated with foam dressing alone (control group) or with a porcine type I collagen dressing material (collagen group). Complete ulcer healing rate was the primary endpoint, and healing velocity and time to 50% size reduction were secondary endpoints. RESULTS: Thirty patients were included (collagen group: 17, control group: 13). There were no significant differences in demographic factors or baseline DFU characteristics. Compared to the control group, the collagen group presented a higher rate of complete healing [82.4% vs. 38.5%, P = .022], faster healing velocity (P < .05), and shorter median time to 50% size reduction (21 versus 42 days; hazard ratio = 1.94, P < .05). CONCLUSIONS: Wound management using collagen materials in DFUs showed faster and complete healing rate.

Altered processing of otolithic information in isolated lateral medullary infarction.

Ocular and cervical vestibular-evoked myogenic potentials (VEMPs) evaluate the function of otolithic pathways in central as well as peripheral vestibular disorders. This study aimed to determine the associations and dissociations of otolithic dysfunction in lateral medullary infarction (LMI), the most well-known disorder of central vestibulopathy. At the Dizziness Clinic of a referral-based University Hospital, 45 patients with isolated LMI (28 men, mean age = 55.6 ± 12.5) had evaluation of the ocular tilt reaction (OTR), tilt of the subjective visual vertical (SVV), and ocular and cervical VEMPs from Janurary 2011 to August 2015 during the acute phase, 1-11 days from the symptom onset (median = 2 days). Almost all (42/45, 93 %) patients showed at least one component of the OTR or SVV tilt that was invariably ipsiversive. In contrast, oVEMPs were abnormal only in 12 (27 %) and cVEMPs in 13 (29 %) patients. Only three patients showed abnormal results in all the tests of the OTR, SVV tilt, and ocular and cervical VEMPs. Abnormal oVEMPs were more common in patients with the OTR than those without (38 vs 6 %, Pearson X 2 test, p = 0.021). In contrast, abnormality of cVEMPs showed no correlation with the presence of OTR (28 vs 31 %, Pearson X 2 test, p = 0.795). In patients with LMI, ipsiversive OTR is invariable, but abnormalities of oVEMPs and cVEMPs were much less common and mostly dissociated even in the patients with abnormal results. This discrepancy in otolithic dysfunction suggests different anatomical substrates and/or dissimilar reciprocal modulation for processing of each otolithic signal in central vestibular structures located in the dorsolateral medulla.

Is Arthroscopic Bone Graft and Fixation for Scaphoid Nonunions Effective?

BACKGROUND: Arthroscopic management of scaphoid nonunions has been advanced as a less invasive technique that allows evaluation of associated intrinsic and extrinsic ligamentous injuries; however, few studies have documented the effectiveness of arthroscopic treatment of scaphoid nonunions and which intraarticular pathologies coexist with scaphoid nonunions. QUESTIONS/PURPOSES: (1) What are the outcomes of arthroscopic management of scaphoid nonunions as assessed by the proportion of patients achieving osseous union, visual analog scale (VAS) pain score, grip strength, range of motion, Mayo Wrist Score (MWS), and Disabilities of the Arm, Shoulder and Hand (DASH) score? (2) What complications are associated with arthroscopic scaphoid nonunion management? (3) What forms of intraarticular pathology are associated with scaphoid nonunions? METHODS: Between 2008 and 2012, we treated 80 patients surgically for scaphoid nonunions. Of those, 45 (56%) had arthroscopic management. During that time, our general indications for using an arthroscopic approach over an open approach were symptomatic scaphoid nonunions without necrosis of the proximal fragment, severe deformities, or arthritis. Of the patients treated arthroscopically, 33 (73%) were available for followup at least 2 years later. There were five distal third, 19 middle third, and nine proximal third fractures. The mean followup was 33 months (range, 24-60 months). Union was determined by CT taken at 8 to 10 weeks after operation with bridging trabecula at nonunion site. VAS pain scores, grip strength, active flexion-extension angle, MWS, and DASH scores were obtained preoperatively and at each followup visit. The coexisting intraarticular pathologies and complications were also recorded. RESULTS: Thirty-two (97%) scaphoid nonunions healed successfully. At the last followup, the mean VAS pain score decreased (preoperative: mean 4.5 [SD 1.8], postoperative: mean 0.6 [SD 0.8], mean difference: 3.9 [95% confidence interval {CI}, 3.2-4.6], p < 0.001) and the mean active flexion-extension angle increased (preoperative: mean 100° [SD 26], postoperative: mean 109° [SD 16], mean difference: 9° [95% CI, 2-16], p = 0.017). The mean grip strength increased (preoperative: mean 35 kg of force [SD 8], postoperative: mean 50 kg of force [SD 10], mean difference: 15 kg of force [95% CI, 11-19], p < 0.001). The mean MWS increased (preoperative: mean 56 [SD 23], postoperative: mean 89 [SD 8], mean difference: 33 [95% CI, 26-41], p < 0.001) and the mean DASH score decreased (preoperative: mean 25 [SD 18], postoperative: mean 4 [SD 3], mean difference: 21 [95% CI, 15-28], p < 0.001). There were no operation-related complications and no progression of arthritis at the last followup. Seventeen patients had coexisting intraarticular pathology, including nine triangular fibrocartilage complex tears (seven traumatic and two degenerative), 17 intrinsic ligament tears (nine scapholunate interosseous ligament tears and eight lunotriquetral interosseous ligament tears), and five mild radioscaphoid degenerative changes. CONCLUSIONS: Arthroscopic management of scaphoid nonunions without severe deformities or arthritis was effective in this small series. Although intraarticular pathologies such as triangular fibrocartilage complex tears and intrinsic ligament injuries commonly coexisted with scaphoid nonunions, patients generally achieved good results. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Arthroscopic repair of a significant (>50%) partial-thickness subscapularis tear concomitant with a full-thickness supraspinatus tear: technical considerations for subscapularis repair (transtendon technique versus tear completion).

BACKGROUND: The purpose of this study was to compare clinical outcomes and structural integrity of arthroscopic repair by either transtendon repair or tear completion for a significant (>50%) partial-thickness articular-side subscapularis tear associated with a full-thickness supraspinatus tear. METHODS: The study population comprised 109 patients who underwent arthroscopic repair for partial-thickness subscapularis tears associated with full-thickness supraspinatus tears with either a transtendon technique (81 patients, group T) or tear completion (28 patients, group C). Pain on a visual analog scale; the Subjective Shoulder Value; the American Shoulder and Elbow Surgeons score; and the University of California, Los Angeles shoulder score were used to compare clinical outcomes between the 2 groups. At 6 months after surgery, magnetic resonance arthrography or computed tomographic arthrography was performed to assess structural integrity. RESULTS: At the 2-year follow-up, there were no significant differences in functional outcomes between groups. In group T, external rotation was reduced significantly from 55° to 51° (P < .001). The subscapularis and overall retear rates were 8% and 19%, respectively, in group T and 12% and 23%, respectively, in group C. There were no significant differences in retear rates between groups. CONCLUSIONS: Arthroscopic repair of partial-thickness subscapularis tears associated with full-thickness supraspinatus tears using either the transtendon technique or tear completion resulted in significant functional improvements in both groups except for postoperative external rotation in group T, and there were no significant differences between groups. The retear rates were also not significantly different between groups. However, after subscapularis repair using the transtendon technique, some patients may have decreased external rotation.

Cerebral arteriovenous malformation associated with moyamoya disease.

The coexistence of moyamoya disease (MMD) with an arteriovenous malformation (AVM) is exceedingly rare. We report two cases of AVM associated with MMD. The first case was an incidental AVM diagnosed simultaneously with MMD. This AVM was managed expectantly after encephalo-duro-arterio-synangiosis (EDAS) as the main feeders stemmed from the internal carotid artery, which we believed would be obliterated with the progression of MMD. However, the AVM persisted with replacement of the internal carotid artery feeders by new external carotid artery feeders from the EDAS site. The AVM was eventually treated with gamma knife radiosurgery considering an increasing steal effect. The second case was a de novo AVM case. The patient was initially diagnosed with MMD, and acquired an AVM eight years later that was slowly fed by the reconstituted anterior cerebral artery. Because the patient remained asymptomatic, the AVM is currently being closely followed for more than 2 years without further surgical intervention. Possible differences in the pathogenesis and the radiologic presentation of these AVMs are discussed with a literature review. No solid consensus exists on the optimal treatment of MMD-associated AVMs. Gamma knife radiosurgery appears to be an effective treatment option for an incidental AVM. However, a de novo AVM may be managed expectantly considering the possible risks of damaging established collaterals, low flow characteristics, and probably low risks of rupture.

Passive skeletal muscle excursion after tendon rupture correlates with increased collagen content in muscle.

PURPOSE: This study was designed to measure time-dependent changes in muscle excursion and collagen content after tenotomy, and to analyze the correlation between muscle excursion and collagen content in a rabbit model. MATERIALS AND METHODS: Twenty-four rabbits underwent tenotomy of the second extensor digitorum longus (EDL) muscles on the right legs and were randomly assigned to three groups based on the period of time after tenotomy (2, 4, and 6 weeks). The second EDL muscles on left legs were used as controls. At each time after tenotomy, passive muscle excursion and collagen content, determined by hydroxyproline content, were measured bilaterally, and the ratio of each value to the normal one was used. RESULTS: The mean ratio of muscle excursion after tenotomy to the value of the control decreased in a time-dependent fashion: 92.5% at 2 weeks, 78.6% at 4 weeks, and 55.1% at 6 weeks. The mean ratio of hydroxyproline content in muscle to the value of the control increased in a time-dependent fashion: 119.5% at 2 weeks, 157.3% at 4 weeks, and 166.6% at 6 weeks. There was a significant negative correlation between the ratio of hydroxyproline content in muscle after tenotomy to the control values and the ratio of muscle excursion after tenotomy to the control values (r=-0.602, p=0.002). CONCLUSION: The decrease in muscle excursion seems to correlate with the increase in collagen content in the muscle in a time-dependent fashion following tenotomy.