Xander Smit

Extensive percutaneous aponeurotomy and lipografting: A new treatment for dupuytren disease

Background: Surgical resection of Dupuytren contracture is fraught with morbidity and prolonged recovery. This article introduces a novel minimally invasive alternative for Dupuytren disease and its outcome. Methods: The procedure consists of an extensive percutaneous aponeurotomy that completely disintegrates the cord and separates it from the dermis. Subsequently, the resultant loosened structure is grafted with autologous lipoaspirate. After 1 week of postoperative extension splinting, patients are allowed normal hand use and are advised to use night splints for 3 to 6 months. The authors treated and report on their experience with 91 patients (99 hands) operated on in Miami and Rotterdam; from 50 patients, the authors report on goniometry (average follow-up, 44 weeks). Results: The contracture from the proximal interphalangeal joint improved significantly from 61 degrees to 27 degrees, and contracture from the metacarpophalangeal joint improved from 37 degrees to –5 degrees. Ninety-four percent of patients returned to normal use of the hand within 2 to 4 weeks and 95 percent were very satisfied with the result. No new scars were added, and a supple palmar fat pad was mostly restored. Complications were digital nerve injury in one patient, postoperative wound infection in one patient, and complex regional pain syndrome in four patients. Conclusions: This new minimally invasive technique shortens recovery time, adds to the deficient subcutaneous fat, and leads to scarless supple skin. By its ability to treat multiple rays, it addresses the abnormality in the entire hand. The procedure is safe and effective, especially for primary cases. Currently, comparative prospective randomized studies are in process to fully determine its role in the treatment of Dupuytren contracture. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV. Figure. No caption available.

Peripheral nerves in the rat exhibit localized heterogeneity of tensile properties during limb movement

Peripheral nerves in the limbs stretch to accommodate changes in length during normal movement. The aim of this study was to determine how stretch is distributed along the nerve relative to local variations in mechanical properties. Deformation (strain) in joint and non‐joint regions of rat median and sciatic nerves was measured in situ during limb movement using optical image analysis. In each nerve the strain was significantly greater in the joint rather than the non‐joint regions (2‐fold in the median nerve, 5‐ to 10‐fold in the sciatic). In addition, this difference in strain was conserved in the median nerve ex vivo, demonstrating an in‐built longitudinal heterogeneity of mechanical properties. Tensile testing of isolated samples of joint and non‐joint regions of both nerves showed that joint regions were less stiff (more compliant) than their non‐joint counterparts with joint: non‐joint stiffness ratios of 0.5 ± 0.07 in the median nerve, and 0.8 ± 0.02 in the sciatic. However, no structural differences identified at the light microscope level in fascicular/non‐fascicular tissue architecture between these two nerve regions could explain the observed tensile heterogeneity. This identification of localized functional heterogeneity in tensile properties is particularly important in understanding normal dynamic nerve physiology, provides clues to why peripheral nerve repair outcomes are variable, and suggests potential novel therapeutic targets.

Static footprint analysis: a time-saving functional evaluation of nerve repair in rats.

Walking track analysis is a widely accepted technique for functional evaluation after sciatic nerve repair in rats, but it is labour‐intensive. In 2000, Bervar described a time‐saving digitised static footprint analysis. In that study there were good correlations between the traditional sciatic function index (SFI) and the newly‐developed static sciatic index (SSI) and static toe spread factor (TSF), respectively. Despite promising results, static footprint analysis is still not widely used. The present study was designed to validate it. After transection of the sciatic nerve, end‐to‐end repair was assessed using video recorded dynamic and static footprints in 45 Wistar rats. We found an even better correlation between the SFI and both the SSI and the static TSF. In conclusion, static footprint analysis is a time‐saving and easy technique for accurate functional assessment of peripheral nerve regeneration in rats.

Significant reduction in neural adhesions after administration of the regenerating agent OTR4120, a synthetic glycosaminoglycan mimetic, after peripheral nerve injury in rats : Technical note

OBJECT Extradural and intraneural scar formation after peripheral nerve injury frequently causes tethering and compression of the nerve as well as inhibition of axonal regeneration. Regenerating agents (RGTAs) mimic stabilizing and protective properties of sulphated glycosaminoglycan toward heparin-binding growth factors. The aim of this study was to assess the effect of an RGTA known as OTR4120 on extraneural fibrosis and axonal regeneration after crush injury in a rat sciatic nerve model. METHODS Thirty-two female Wistar rats underwent a standardized crush injury of the sciatic nerve. The animals were randomly allocated to RGTA treatment or sham treatment in a blinded design. To score neural adhesions, the force required to break the adhesions between the nerve and its surrounding tissue was measured 6 weeks after nerve crush injury. To assess axonal regeneration, magnetoneurographic measurements were performed after 5 weeks. Static footprint analysis was performed preoperatively and at Days 1, 7, 14, 17, 21, 24, 28, 35, and 42 postoperatively. RESULTS The magnetoneurographic data show no significant difference in conduction capacity between the RGTA and the control group. In addition, results of the static footprint analysis demonstrate no improved or accelerated recovery pattern. However, the mean pullout force of the RGTA group (67 +/- 9 g [mean +/- standard error of the mean]) was significantly (p < 0.001) lower than that of the control group (207 +/- 14 g [mean +/- standard error of the mean]). CONCLUSIONS The RGTAs strongly reduce nerve adherence to surrounding tissue after nerve crush injury.

Recovery of neurophysiological features with time after rat sciatic nerve repair: a magneto-neurographic study

Abstract  Experimental assessment of peripheral nerve regeneration in rats by electrophysiology is controversial due to low reproducibility of electrophysiological indicators and diminished quantitative evaluation in conventional experimental set‐ups. Magnetoneurography (MNG) counteracts these drawbacks by magnetically recording electrophysiological signals ex vivo, thereby providing accurate and quantitative data. In 50 rats, sciatic nerve transection was followed by direct repair. MNG outcome parameters, footprints [static toe spread factor (TSF); function] and muscle weight (MW) were studied for their recovery pattern from 2 to 24 weeks. By using MNG, we showed that the regeneration process still continues when functional recovery (static TSF) becomes stagnant. With regression analysis, MNG parameters amplitude, amplitude area and conduction velocity (CV) demonstrated moderate significant correlation with MW, whereas CV was not significantly associated with static TSF. No significant association exists between MW and static TSF. A Kaplan–Meier survival curve revealed that autotomy/contracture of rat hind paws was not related to decreased MNG outcome values. In conclusion, this study highlights and discusses the dissimilarities between direct (MNG) and indirect (static TSF and MW) assessment techniques of the regeneration process. We emphasise the significance of MNG as a direct derivative of axon regeneration in experimental rat studies. Additionally, we stress the must for right‐left ratios, as neurophysiological indicators vary with age, and we confute possible bias in footprint analysis caused by exclusion of autotomy/contracture animals.

Predictors of Patient Satisfaction with Hand Function after Fasciectomy for Dupuytren's Contracture.

Background: This study examined patient satisfaction with hand function after fasciectomy for Dupuytren’s contracture and determined which preoperative patient- and disease-specific factors predicted this satisfaction. Methods: Demographics and disease-specific factors were assessed from a prospective cohort of 194 patients who completed the Michigan Hand Outcomes Questionnaire preoperatively and underwent limited fasciectomy between 2011 and 2014 at six hand surgery practice sites. To evaluate satisfaction with hand function, patients were asked to complete the Michigan Hand Outcomes Questionnaire during the first year after fasciectomy. After patients were classified into a satisfied and an unsatisfied category using the question that specifically pertains to satisfaction with hand function, the authors applied multivariate logistic regression modeling to identify independent predictors of patient satisfaction. Results: At an average of 10 months (range, 6 to 12 months) after fasciectomy, 84 percent (n = 163) of the patients were satisfied with their hand function. In multivariate analyses adjusting for the degree of postoperative residual contracture (p < 0.001) and complications (p < 0.001), a higher preoperative Michigan Hand Outcomes Questionnaire hand appearance subscore and male gender predicted a higher likelihood of becoming satisfied after fasciectomy. Other patient- and disease-specific factors did not show evidence for an association with patient satisfaction. Conclusions: The findings of this study suggest that providers should consider assessing concerns about the appearance of the hand in patients with Dupuytren’s contracture. They also highlight the importance of complication prevention and full contracture correction from the patient’s perspective. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.