The Intramedullary Skeletal Kinetic Distractor (ISKD) (Orthofix Inc, Lewisville, TX, USA) is an intramedullary device designed for more comfortable limb lengthening than that with external fixators; lengthening is achieved with this nail using rotational oscillation between two telescoping sections. However, the degree to which this device achieves this goal and its complication rate have not been fully documented. We determined (1) the frequency with which distraction was not achieved at the desired rate, (2) whether pain differed between patients with normally and abnormally distracting nails, (3) risk factors for abnormal nails, and (4) other complications. We analyzed 35 lengthening segments (26 femurs, nine tibias) in 19 patients. Mean length achieved was 47 mm. Femoral nails were categorized into four groups according to distraction rate: normal, runaway (unintentionally faster rate [> 1.5 mm/day]), difficult-to-distract (slower rate [< 0.8 mm/day] requiring manual manipulation but not requiring general anesthesia), and nondistracting (slower rate [< 0.8 mm/day] requiring manual manipulation under general anesthesia or reosteotomy). Possible risk factors, including age, BMI, preoperative thigh circumferences, degree of intramedullary overreaming, and length of the thicker portion of the nail within the distal fragment, were compared among groups. VAS pain scores were compared among groups under three conditions: rest, physiotherapy, and distraction motion. Complications were also analyzed. Minimum followup was 15 months (mean, 26 months; range, 15–38 months) after first-stage surgery. Abnormal distraction rate was observed in 21 of 35 segments (60%; 17 femurs, four tibias). VAS pain scores showed no differences among groups during rest or physiotherapy but were higher (p = 0.02) in the problematic nails (7–8 points) versus normal nails (3 points) during distraction. Only mean length of the thicker portion of the nail within the distal fragment differed between normally and abnormally distracting nails (95 mm versus 100 mm; p = 0.03), although this was unlikely to be clinically important. Complications occurred in 10 patients (53%), including five with decreased ankle ROM during distraction, four with delayed bone healing, and one with mechanical device failure during distraction. Rate control was difficult to achieve with the ISKD nail for femoral and tibial lengthenings, complications were relatively common, and among patients in whom rate control was not achieved, pain levels were high. Based on our findings, we believe that surgeons should avoid use of this nail. Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

There have been debates about the results of surgical treatment in older children, even though many studies showed excellent results in pediatric trigger thumb. The objective of this study was to identify the possible problems or complications related to the delayed surgery for trigger thumb in children. Authors clinically reexamined the patients who had undergone A1 pulley release above the age of 5 years and analyzed the results of surgical treatment. A retrospective study of 31 trigger thumbs was performed on 23 consecutive children treated using a standardized surgical technique. The mean age at the operation was 7.46 years and average period of clinical follow-up was 2 years and 3 months. We investigated the presence or absence of interphalangeal joint flexion contracture, triggering, recovery of active range of motion, postoperative period that the patients get more than 0 degree interphalangeal joint extension, and complications. Flexion contracture and painful triggering were successfully relieved after surgery in all cases. Patients showed variable periods in improving temporary extension weakness of interphalangeal joint, but there was no statistical difference in the final result between early and delayed improvement or between symptom duration and healing time. None of these patients had any postoperative complications. Surgical treatment with A1 pulley release for over 5 years of age resulted in successful resolution of trigger thumb and satisfactory clinical outcome in all our cases regardless the age at the time of surgery. From the author's findings, we can expect satisfactory results of surgical treatment in pediatric trigger thumb even in the case of delayed diagnosis or late treatment.

A large number of studies have focused on the role of substance P (SP) and the neurokinin-1 receptor (NK1R) in the pathogenesis of a variety of medical conditions. This review provides an overview of the role of the SP-NK1R pathway in the pathogenesis of musculoskeletal disorders and the evidence for its role as a therapeutic target for these disorders, which are major public health problems in most countries. To summarize, the brief involvement of SP may affect tendon healing in an acute injury setting. SP combined with an adequate conjugate can be a regenerative therapeutic option in osteoarthritis. The NK1R antagonist is a promising agent for tendinopathy, rheumatoid arthritis, and osteoarthritis. Research on the SP-NK1R pathway will be helpful for developing novel drugs for osteoporosis.

Background: The purpose of this study was to determine the reaction mechanism of corticosteroid by analyzing the expression patterns of neuropeptides (substance P (SP), calcitonin gene related peptide (CGRP)) and of cytokines (interleukin (IL)-1α, tumor growth factor (TGF)-β) after corticosteroid treatment in lateral epicondylitis. In addition, we also investigated whether corticosteroid influenced tenocyte viability. Methods: The corticosteroid triamcinolone acetonide (TAA) was applied to cultured tenocytes of lateral epicondylitis, and the changes in the mRNA expressions of neuropeptides and cytokines and tenocyte viabilities were analyzed at seven time points. Quantitative real-time polymerase chain reaction and an MTT assay were used. Results: The expression of SP mRNA was maximally inhibited by TAA at 24 hours but recovered at 72 hours, and the expressions of CGRP mRNA and IL-1α mRNA were inhibited at 24 and 3 hours, respectively. The expression of TGF-β mRNA was not significant. Tenocyte viability was significantly reduced by TAA at 24 hours. Conclusions: We postulate that the reaction mechanism predominantly responsible for symptomatic relief after a corticosteroid injection involves the inhibitions of neuropeptides and cytokines, such as, CGRP and IL-1α. However the tenocyte viability was compromised by a corticosteroid.