Gliding Surface Research Articles

Accurate Measurement of Temperature Change of Gliding Surface of Ski Associated with Snow Friction

Accurate Measurement of Temperature Change of Gliding Surface of Ski Associated with Snow Friction

Retromalleolar Groove Deepening in Recurrent Peroneal Tendon Dislocation: Technique Tip.

Peroneal tendon dislocations are most prevalent in the active and athletic population, so accurate diagnosis and management are essential for optimal return of function. Although many nonoperative and surgical management options have been described, the optimal treatment method continues to be debated. In this technique article, a modified retromalleolar groove–deepening technique is described for addressing all anatomic variations of the posterior distal fibula and retromalleolar groove without unduly disturbing the important anatomic facets meant for retention in this region. This technique is indicated for chronic dislocated peroneal tendons, recurrent dislocating peroneal tendons, and dislocation of the tendons after acute injury with a shallow fibular peroneal groove. Although it remains unclear what effect a cortically abraded fibular gliding surface or forceful cortical impaction on the fibrocartilage gliding surface might have on peroneal tendon integrity and function long term, it would seem preferable to avoid such techniques if reliable alternatives are available.

Outcome of proximally based sural artery flap for the coverage of defects around knee joint

Introduction: Soft tissue defects around the knee occour commonly. Various flaps have been described for coverage of these defects around the knee, such as local flaps, cross-leg flap or free flaps etc, but, knee joint function and appearance frequently compromise the outcome. Materials and Methods: A retrospective study comprising of eight patients was conducted in a tertiary level trauma center. Proximal based sural artery fasciocutaneuos flap was used to cover tissue defects. Results: No morbidity of the donor site and no functional deficits of the knee or ankle were detected in any of the cases. All flaps survived without any major complications. Most of the patients were satisfied with this thin and sensate flap. Conclusion: The proximally based sural artery flap is easy to raise and execute. It provides a thin, sensate and good gliding surface. This flap is easy to learn and cosmesis is excellent at the recipient site. Hence the authors recommend it to be ideal choice for the coverage of the defects mentioned in the study.

Efficacy of anti-adhesion gel of carboxymethylcellulose with polyethylene oxide on peripheral nerve: Experimental results on a mouse model

Perineural scar formation is responsible for pain and loss of function after surgical procedures. Neurolysis and application of anti-adhesion gels are required to restore a gliding surface. We tested a carboxymethylcellulose (CMC) and polyethylene oxide (PEO) gel on mouse sciatic nerve to describe its safety and efficacy. Adult mice underwent a surgical procedure in which we burned the muscular bed of the sciatic nerve bilaterally (Burned group) and applied anti-adhesion gel to 1 of the nerves (Burned+gel group). After 3 weeks, we studied scar tissue by biomechanical and histological evaluation. Both histological and biomechanical analysis showed that the gel reduced perineural scarring. The difference between the Burned and Burned+gel groups was statistically significant. CMC-PEO gel can reduce perineural scar tissue. In histological section, scar tissue was present in both groups, but in the Burned+gel group a gliding surface was identified between scar and nerve.

Processes of chemoionization in the course of inflammation of a methane-oxygen mixture by a high-current gliding surface discharge in a closed chamber

Results are presented from experiments on the inflammation of a stoichiometric methane-oxygen mixture by a high-current multielectrode spark-gap in a closed cylindrical chamber. It is shown that, in both the preflame and well-developed flame stages, the gas medium is characterized by a high degree of ionization (n e ≈ 1012 cm−3) due to chemoionization processes and a high electron-neutral collision frequency (ν e0 ≈ 1012 s−1).

The Hsp70-like StkA functions between T4P and Dif signaling proteins as a negative regulator of exopolysaccharide in Myxococcus xanthus.

Myxococcus xanthus displays a form of surface motility known as social (S) gliding. It is mediated by the type IV pilus (T4P) and requires the exopolysaccharide (EPS) to function. It is clear that T4P retraction powers S motility. EPS on a neighboring cell or deposited on a gliding surface is proposed to anchor the distal end of a pilus and trigger T4P retraction at its proximal end. Inversely, T4P has been shown to regulate EPS production upstream of the Dif signaling pathway. Here we describe the isolation of two Tn insertions at the stk locus which had been known to play roles in cellular cohesion and formation of cell groups. An insertion in stkA (MXAN_3474) was identified based on its ability to restore EPS to a pilA deletion mutant. The stkA encodes a DnaK or Hsp70 homolog and it is upstream of stkB (MXAN_3475) and stkC (MXAN_3476). A stkB insertion was identified in a separate genetic screen because it eliminated EPS production of an EPS+ parental strain. Our results with in-frame deletions of these three stk genes indicated that the stkA mutant produced increased level of EPS while stkB and stkC mutants produced less EPS relative to the wild type. S motility and developmental aggregation were affected by deletions of stkA and stkB but only minimally by the deletion of stkC. Genetic epistasis indicated that StkA functions downstream of T4P but upstream of the Dif proteins as a negative regulator of EPS production in M. xanthus.

Post-traumatic radioulnar synostosis treated effectively with tissue expander capsule interposition: a novel technique

Post-traumatic radioulnar synostosis is a rare condition characterised by abnormal fibro-osseous union between radius and ulna along the length of the interosseous membrane, resulting in loss of forearm pronation and supination. Various surgical techniques have been described and numerous interpositional materials have been used. We present a novel technique of utilising a tissue expander capsule as the interpositional gliding surface. This technique provides an autologous capsule and an expanded adipofascia, which are well vascularised for increased length and reliability.

The medial sural artery perforator flap and its application in electrical injury to the hand

We describe the use of a free medial sural artery perforator flap to reconstruct a complex composite defect to the dorsum of the right index finger following a low voltage electrical injury. The resulting defect was a 3.5 × 5 cm full thickness wound, with segmental tendon loss and loss of underlying periosteum. Due to both size and local vascular injury related to the mechanism, free tissue transfer was felt to be the most reliable option to resurface the composite defect in a single stage. The medial sural artery perforator flap, for reasons outlined below, was felt to be the best option: 1. Thin profile. 2. Vascularised fascia can be taken as a tongue, adjacent to the skin paddle: a gliding surface to prevent the tendon graft sticking to exposed bone. 3. Long pedicle: micro-anastomosis away from zone of injury. 4. Little donor site morbidity: can be closed directly (if <6 cm wide) and does not require sacrifice of any major blood vessel. 5. Can be harvested with nerve and tendon from the same wound. 6. Can include as little or as much tissue required and compared to other fasciocutaneous flaps matches the texture and thickness of the hand most closely. We describe the reconstruction of the composite defect on day 42 post-injury, following one prior debridement. This case highlights the versatility and suitability of the medial sural artery flap in the reconstruction of complex hand burns with resulting composite defects.

Optical imaging of articular cartilage degeneration using near-infrared dipicolylamine probes

Articular cartilage is the hydrated tissue that lines the ends of long bones in load bearing joints and provides joints with a smooth, nearly frictionless gliding surface. However, the deterioration of articular cartilage occurs in the early stages of osteoarthritis (OA) and is clinically and radiographically silent. Here two cationic near infrared fluorescent (NIRF) dipicolylamine (DPA) probes, Cy5-DPA-Zn and Cy7-DPA-Zn, were prepared for cartilage degeneration imaging and OA early detection through binding to the anionic glycosaminoglycans (GAGs). The feasibility of NIRF dye labeled DPA-Zn probes for cartilage degeneration imaging was examined ex vivo and in vivo. The ex vivo studies showed that Cy5-DPA-Zn and Cy7-DPA-Zn not only showed the high uptake and electrostatic attractive binding to cartilage, but also sensitively reflected the change of GAGs contents. In vivo imaging study further indicated that Cy5-DPA-Zn demonstrated higher uptake and retention in young mice (high GAGs) than old mice (low GAGs) when administrated via local injection in mouse knee joints. More importantly, Cy5-DPA-Zn showed dramatic higher signals in sham joint (high GAGs) than OA side (low GAGs), through sensitive reflecting the change of GAGs in the surgical induced OA models. In summary, Cy5-DPA-Zn provides promising visual detection for early cartilage pathological degeneration in living subjects.

Reconstruction of a Functional Gliding Surface With Extensor Retinaculum in Extensor Tendon Reconstruction in the Digits

Tendon gliding is key to optimal recovery of hand function after complex tendon injuries. Gliding is facilitated by a low-friction gliding surface that is normally provided by the periosteum of the underlying bone. However, significant injuries may damage the periosteum, which must be reconstructed to allow uninterrupted tendon excursion. The absence of the periosteum may compromise a tendon's ability to glide freely, thereby limiting the range of motion. Six digits in 4 patients with complex, composite soft tissue defects involving tendon, periosteum, and skin of the hand underwent surgical repair. Each digit had disruption of the bony cortex underlying the tendon injury including periosteal loss. Through an incision on the dorsum of the ipsilateral wrist, an extensor retinaculum graft corresponding to the size of the periosteal defect was harvested. It was then sutured into place over the bare cortex to replace the lost periosteum. All the 6 digits in the 4 patients had complete return to function. Additionally, all patients had near normal strength in the repaired hand along with excellent tendon excursion in both flexion and extension. The average time of follow-up of this series of patients was 1.5 years. Extensor retinaculum grafting to replace lost periosteum is a technique that is easily used, uses locally available autogenous tissues, and produces excellent tendon function. Additionally, the histologic similarities between extensor retinaculum and periosteum add scientific merit to this novel approach. On the basis of our experience, we recommend the use of extensor retinaculum for periosteal reconstruction to provide an adequate gliding surface for a reconstructed tendon.

Bipedicled flap reconstruction of soft tissue defect with Achilles tendon exposure

Soft tissue defects exposing the Achilles tendon are common in patients who have undergone trauma or in those with pressure ulcers associated with vascular diseases. Here, we present our recent experience of using a bipedicled fasciocutaneous flap to resurface the complex soft tissue defect and provide a gliding surface for the exposed Achilles tendon. The donor-sites were covered with split-thickness skin grafts and healed well without complications. The bipedicled fasciocutaneous flap survived completely, and the wound healed satisfactorily at 2 months follow-up. The bipedicled fasciocutaneous flap is a reliable flap for coverage of defects overlying the Achilles tendon, especially in patients with vascular problems and/or advanced age. The ease of handling, short operative time, and early recovery of mobilization function are of great benefit to patients. This method can be a valuable alternative for defect reconstructions overlying the Achilles tendon, with satisfactory results both functionally and cosmetically.

Tissue engineering in flexor tendon surgery: current state and future advances

Tissue engineering of flexor tendons addresses a challenge often faced by hand surgeons: the restoration of function and improvement of healing with a limited supply of donor tendons. Creating an engineered tendon construct is dependent upon understanding the normal healing mechanisms of the tendon and tendon sheath. The production of a tendon construct includes: creating a three-dimensional scaffold; seeding cells within the scaffold; encouraging cellular growth within the scaffold while maintaining a gliding surface; and finally ensuring mechanical strength. An effective construct incorporates these factors in its design, with the ultimate goal of creating tendon substitutes that are readily available to the reconstructive hand surgeon.

Apoptosis in Adhesions and the Adhesion-Tendon Gliding Interface: Relationship to Adhesion-Tendon Gliding Mechanics

Adhesion formation is closely related to tendon-gliding function. We aimed to investigate apoptosis (programmed cell death) in adhesions and tendons and study its relationship to the mechanics of adhesions and healing tendons. The flexor digitorum profundus tendons of 30 long toes in 15 chickens were completely transected and repaired surgically. At postoperative weeks 4, 6, and 8, tendon-gliding excursions were tested and adhesion scores were recorded. Tendons and surrounding adhesions were then harvested for analysis of apoptosis using in situ terminal deoxynucleotidyl transferase dUTP (deoxyuridine triphosphate) nick end labeling assay. Three-dimensional image reconstruction was used to provide an overall view of cellular distribution in tendons and adhesions. Finally, we analyzed the correlation between the apoptotic index measured at the adhesions and the gliding excursions. Ten uninjured tendons served as normal controls. Apoptosis was found to be a dominant cellular event in the adhesion tissues at both the adhesion-tendon gliding interface and the adhesion core. The apoptotic index in the adhesions was generally above 20% to 50%. The apoptotic index was significantly higher in the adhesions than in the junction region of the cut tendon ends at weeks 4, 6, and 8. A higher apoptotic index in the adhesions significantly correlated to lower tendon excursions at week 6. Apoptosis in adhesions and at the adhesion-tendon interface is a prominent event in the tendon-healing process. The tendons exhibiting a lower tendon-gliding amplitude, meaning more severe adhesions, tended to have a greater apoptotic index in their adhesions during a certain period of the tendon-remodeling process. Apoptosis in the adhesions and at the adhesion-tendon interface may contribute remarkably to the fate of adhesions and the restoration of the tendon gliding surface, which may be closely related to the tendon function.

Magnetoelectric Confinement and Stabilization ofZPinch in a Soft–x-RayAr+8Laser

Magnetoelectric confinement and stabilization of the plasma column in a soft-x-ray Ar(+8) laser, which is excited by a capillary Z pinch, via the combined magnetic and electric fields of the gliding surface discharge is experimentally demonstrated. Unlike soft-x-ray lasers excited by the conventional capillary Z pinches, the magnetoelectric confinement and stabilization of plasma do provide the laser operation without using any external preionization circuit.

Flagella stator homologs function as motors for myxobacterial gliding motility by moving in helical trajectories

Many bacterial species use gliding motility in natural habitats because external flagella function poorly on hard surfaces. However, the mechanism(s) of gliding remain elusive because surface motility structures are not apparent. Here, we characterized the dynamics of the Myxococcus xanthus gliding motor protein AglR, a homolog of the Escherichia coli flagella stator protein MotA. We observed that AglR decorated a helical structure, and the AglR helices rotated when cells were suspended in liquid or when cells moved on agar surfaces. With photoactivatable localization microscopy, we found that single molecules of AglR, unlike MotA/MotB, can move laterally within the membrane in helical trajectories. AglR slowed down transiently at gliding surfaces, accumulating in clusters. Our work shows that the untethered gliding motors of M. xanthus, by moving within the membrane, can transform helical motion into linear driving forces that push against the surface.

Do Changing Toll-like Receptor Profiles in Different Layers and Grades of Osteoarthritis Cartilage Reflect Disease Severity?

Cartilage degeneration in osteoarthritis (OA) leads to release of potential danger signals. The aim of our study was to profile OA cartilage for the Toll-like receptor (TLR) danger signal receptors. Osteochondral cylinders from total knee replacements were graded using OA Research Society International score and stained for proteoglycans, collagenase-cleaved type II collagen, and TLR 1-10, which were analyzed histomorphometrically. Grade 1 OA lesions contained 22%-55% TLR 1-9-positive cells in the surface zone, depending on the TLR type. In Grade 2 TLR, immunoreactivity was 60%-100% (p < 0.01) and it was even higher in Grades 3 and 4 (p < 0.01 vs Grade 1). TLR-positive cells in Grade 1 middle zone were low, 0-19.9%, but were 5.1%-32.7% in Grade 2 (p < 0.01) and 34%-83% in Grades 3-4 samples (p < 0.001). TLR values in Grade 5 were low (14.3%-28.7%; p < 0.001). In Grades 3-4 OA, cartilage matrix stained strongly for TLR. In Grade 1, COL2-3/4M was restricted to chondrocytes, but was increasingly seen in matrix upon progress of OA to Grade 4, and then declined. Cells in the gliding surface zone are fully equipped with TLR in mild OA. Their proportion increases and extends to the middle or even the deep zone, reflecting OA progression. COL2A-3/4M staining suggests Endo180-mediated intake for intralysosomal degradation by cathepsins in Grade 1, but in higher grades this chondrocyte-mediated clearance fails and the matrix demonstrates extensive collagenase-induced damage. Detached and/or partially degraded matrix components can then act as endogenous danger signals (damage-associated molecular patterns or DAMP) and stimulate increasingly TLR-equipped chondrocytes to inflammation. At the peak inflammatory response, soluble TLR may exert negative feedback, explaining in part the low TLR levels in Grade 5 OA.

A reliable option for wrist soft tissue defects: adipofascial flaps for immediate and late reconstruction

Extensive volar injuries are common and devastating because of the long-term adhesion potency. The gliding effect of the adipose tissue is essential in preventing tendon adhesions after injury. In this study, we present the results of performing adipofascial flaps for the reconstruction of soft tissue defects following wrist trauma. The study included 15 patients. Adipofascial flaps were performed for immediate coverage of the tissue defect in 2 patients and for late adhesion-related problems in 13 patients. Flap dimensions varied from 8 × 14 to 8 × 20 cm. All but one of the flaps and skin grafts survived uneventfully. None of the patients, whether immediate or late, required another operation to address further adhesion problems. Since adipofascial flaps provide a gliding surface, they are a good choice for immediate coverage of soft tissue defects in the wrist that are not suitable for skin grafting alone as well as for late adhesion-related problems.

Der temporoparietale Faszienlappen zur Rekonstruktion von Weichteildefekten

Soft tissue reconstruction with a temporoparietal fascial flap (TPFF). Defect coverage with thin, pliable, and well-vascularized tissue. A bilayered TPFF provides a gliding surface in tendon reconstruction. Further options include TPFF harvest with overlying skin or subjacent bone for composite tissue reconstruction or the application as a sensate local fascial flap. Maximum defect dimensions: 17 × 14cm. Absolute: prior injury to the flap or flap pedicle, temporal arteritis, Moyamoya syndrome, defects with volume deficit. Relative: alopecia along the planned incision. Pedicle location is outlined using Doppler ultrasound. Injection of the incision line with diluted epinephrine solution. Skin incision with subsequent visualization of the temporoparietal fascia and supplying vessels. Skin flaps are raised carefully paying special attention to the hair follicles (CAVE: postoperative alopecia). Primary closure of the donor site. Defect coverage with pedicled or free TPFF with subsequent full or split-thickness skin grafting. Dressing: Bolster or V.A.C. Immobilization/elevation in the setting of extremity reconstruction. Removal of bolster dressing or V.A.C. on postoperative day5. Dangling protocol instituted on postoperative day7. Removal of sutures/staples at the donor site on postoperative day5-7 and at the recipient site on postoperative day12-14. The TPFF was utilized for soft tissue reconstruction in 8patients. A pedicled TPFF was used in 2patients. Mean time to healing was 16.3days. Mean follow-up was 13.4months. Successful reconstructive results with satisfactory functional and aesthetic appearance were obtained in all patients. Complications were encountered in 3patients and included alopecia at the donor site and iatrogenic injury to the frontal branch of the facial nerve. Vascular compromise was observed in the early postoperative period in a third patient. However, operative revision resulted in successful flap salvage.

Composite anterolateral thigh perforator flaps in the management of complex hand injuries

The anterolateral thigh (ALT) fasciocutaneous flap has been well described for hand skin cover, however its use in its composite (multiple tissue) form incorporating bone, muscle and/or fascia has been less well described. We report the usefulness of the composite ALT flap in six complex hand trauma cases, four male and two female (age range 14-46 years). The palm of the hand was affected by injury in three cases, the dorsum in two cases, and the radial side in one case. The first web formed part of the injury in three cases. There was variable involvement of the tendons, nerves and bones. Fascia lata was included in the flap to provide a gliding surface in four cases, part of the vastus lateralis muscle was included to obliterate dead space in two cases and to create a first web in one case, and a bone block from the iliac crest was included to reconstruct the lost metacarpals in one case. All flaps survived with minimal complications. This work shows that the anterolateral thigh composite flap is a reliable option when multiple tissue types are required in hand reconstruction.

Free‐flap resurfacing of tissue defects in the foot due to large gouty tophi

Large or extensive gouty tophi on the feet can cause functional impairment, drainage sinus, and infected necrosis, finally resulting in complex soft-tissue defects with tendon, joint, bone, nerve, and vessel exposure. Reconstruction of complex soft-tissue defects of the foot is still challenging. The purpose of this report was to review the outcomes of free-flap reconstructive surgery for treating the metatarsal joint defects of the feet caused by chronic tophaceous gout. Ten patients who had large tophus masses (>5 cm) and ulceration on the feet were admitted to our hospital between September 2006 and September 2010. Six patients underwent free-flap reconstruction after debridement to resurface the circumferential wound, protect the underlying structures, and provide a gliding surface for exposed tendons. The patients' age, sex, comorbidities, location and size of the defects, reconstructive procedures, surgical outcomes, complications, follow-ups, and recurrence of tophaceous gout were reviewed and recorded. The mean patient age was 49.8 years (range, 36-72 years). The average skin defect size was 92.2 cm(2) . Five patients were treated using free anterolateral thigh flaps, and 1, using a free medial sural flap. These free flaps were safely raised and showed excellent functional and cosmetic results, with a mean follow-up of 31.7 months (range, 7-50 months). Chronic tophaceous gout can cause severe skin infection and necrosis, even resulting in deformity or sepsis if left untreated. Surgical debridement is inevitable in patients with extensive wounds. We reconstructed the large, ulcerative skin and soft-tissue defects on the dorsum of the foot by performing free-flap reconstruction after adequate debridement and achieved good functional and cosmetic results.