Synovial Flap Research Articles

Recurrent carpal tunnel syndrome: Outcomes after neurolysis and synovial flap

ObjectivesIf symptoms recur after primary neurolysis of the median nerve, surgical revision is required. Soltani et al. (2013) demonstrated that surgical revision with vascularized flap coverage had a higher success rate (86%) than surgical revision without a flap (75%). The aim of this retrospective study was to present clinical outcomes in 36 cases of secondary open neurolysis of the median nerve, with synovial flap in case of recurrent carpal tunnel syndrome. MethodThirty-three patients (36 hands) who had undergone secondary neurolysis of the median nerve combined with synovial flap coverage between 2012 and 2019 were selected for this study. We included only recurrent carpal tunnel syndrome cases presenting with scarring of the transverse carpal ligament or epineural fibrosis of the median nerve and with a symptom-free period of at least 3 months. The results were ranked on a 4-point scale as excellent, good, null or poor, depending on progression at last follow-up. ResultsDescriptive analysis showed that 80% of patients had a positive outcome (excellent 33%, good 47%), 6% null outcome and 14% poor outcome. ConclusionThis is an interesting, relatively non-invasive surgical option, and should be part of the therapeutic armamentarium for recurrent carpal tunnel syndrome in case of adherence of the nerve to the transverse carpal ligament.

Surgery of True Recurring Median Carpal Tunnel Syndrome with Synovial Flap by Wulle Plus Integument Enlargement Leads to a High Patient's Satisfaction and Improved Functionality.

This prospective study was conducted to investigate electrophysiological qualities and patient’s satisfaction of a synovial gliding tissue flap in treating true recurring carpal tunnel syndrome. In 14 patients (11 women, three men), 15 median nerves were included in this retrospective study. For all 15 nerves, motor and sensory nerve conduction velocity, compound muscle action potential, a Visual Analogue Scale-score (VAS-score) questionnaire and an adapted Levine-Test were evaluated pre- and postoperatively. All participants underwent operative neurolysis of the median nerve, which was then enwrapped by a synovial gliding tissue flap. Eleven procedures were completed by integument enlargement. Follow-up period was 12 months. Postoperatively, distal latency decreased significantly by 15.6%. Compound muscle action potential and sensory nerve conduction velocity did not improve significantly. VAS score regarding pain reduced highly significantly with 74.1%. The adapted Levine-Test function score improved highly significantly with 39.2%. The synovial gliding tissue flap lead to an excellent patient’s satisfaction for treating true recurring carpal tunnel syndrome. Primary wound closure should be completed with integument enlargement if needed.

Effects of a synovial flap and gelatin/β-tricalcium phosphate sponges loaded with mesenchymal stem cells, bone morphogenetic protein-2, and platelet rich plasma on equine osteochondral defects

This study aimed to evaluate the efficacy of a synovial flap and gelatin/β-tricalcium phosphate (GT) sponge loaded with mesenchymal stem cells (MSCs), bone morphogenetic protein-2 (BMP-2), and platelet rich plasma (PRP) for repairing of osteochondral defects in horses. Osteochondral defects were created on the medial condyle of both femurs (n=5). In the test group, a GT sponge loaded with MSCs, BMP-2, and PRP (GT/MSCs/BMP-2/PRP) was inserted into the defect and then covered with a synovial flap. In the control group, the defect was treated only with the GT/MSCs/BMP-2/PRP. The test group showed significantly higher macroscopic scores than the control group. In addition, hyaline cartilaginous tissue was detected in the test group in areas larger than those in the control group. This study demonstrated that the combination of a synovial flap and GT sponge loaded with MSCs, BMP-2, and PRP promoted osteochondral regeneration in an equine model.

Arterial vascularization of the flexor digitorum superficialis synovial flap. An anatomical study

Among the various techniques proposed to protect the median nerve from scarring and to provide it with a vascular supply, the synovial flap represents a simple and effective method. The flap is taken from the flexor tendons sheath and results in a thin and richly vascularized tissue that will act as a barrier to scarring and provide neovascularization to improve nerve regeneration and gliding. The aim of this study was to evaluate the arterial vascularization of this flap to assess its reliability. An anatomic study was carried out on 24 fresh upper limbs infused with colored and radiopaque solutions before or after flap elevation. Anatomical findings showed the synovial flap to be supplied by a consistent vascular pedicle arising from the ulnar artery 2 to 5 centimeters proximal to the pisiform bone and running between the flexor tendons of the ring and little fingers. The synovial flap is known to be a simple and effective method for protecting the median nerve. The present study shows that its consistent vascularization makes it a reliable technique. We believe this procedure is relevant for the treatment of recurring carpal tunnel syndrome.

Coverage of neuroma in continuity

Neurogenic pain can develop after microsurgical repair of a median nerve injury or when the lesion is underestimated and therefore not treated at all. Nerve injury with neuromatous pain may be associated with tumefaction at the wrist, increased pain and tingling when tapped [1]. The aim of the treatment is to both minimize pain and preserve residual function of the median nerve. Surgical procedures such as neurolysis do not always relieve the patients’ pain. Reconstruction with grafts is reserved only for cases with very poor sensory and motor recovery. Neurolysis should be performed carefully to avoid devascularization of the nerve and formation of a new scar around the nerve [2]. Particular attention has been given to the coverage and wrapping of a neuroma with different pedicle flaps as the pronator quadratus muscle flap [3], the Becker flap [4], the reverse island radial fascial flap with or without inclusion of the radial artery [2,5-7] and the local synovial flap [8]. With regards to free flaps, Wintsch [9] believes that a thin flap of gliding fascia is the ideal flap to cover a nerve, whereas Jones [10] advocates the use of a small hemi-latissimus dorsi muscle flap. The lateral arm flap [2,11,12] and the scapular flap [2,11] represent other options but the thickness of the subcutaneous tissue and the overlying skin often produce very prominent flaps [10]. Goitz and Steichen [13] reported the coverage of a scarred median nerve with a free omental flap. The purpose of this study is to review the treatment of painful neuroma of the median nerve at the wrist treated with external neurolysis and coverage using the ulnar artery perforator adipofascial flap (UAPAF) or the radial artery perforator adipofascial flap (RAPAF).

Couverture d’une perte de substance palmaire par un lambeau synovial des fléchisseurs superficiels des doigts

Post-traumatic palmar soft tissue defects are a difficult problem in plastic surgery and many techniques have been described. We report the case of a 41-year-old patient with a large palmar soft tissue defect of the right hand due to a work accident. The classical flaps used in this indication were not usable. So, we chose the synovial flap of the Flexor digitorum superficialis to cover this palmar defect. We discuss the coverage possibilities for a hand palmar defect in emergency, and the use of the synovial flap in this indication. This case report shows that the synovial flap could be an option for the coverage of palmar soft tissue defects.

Anatomical study and clinical relevance of the flexor superficialis synovial flap: an assessment of 31 hand dissections

The authors present an anatomical study of the flexor digitorum superficialis synovial flap and its clinical application for palmar soft tissue defects in hand trauma. Green latex was injected into the brachial artery of thirty-one human upper limbs from corpses donated to science. Anatomical features of this pedicled flap were assessed: arterial vascularization, dimensions and covering surface. The anatomical support of this flap is the synovial tissue of the flexor tendons, and particularly the superficial layer of the synovial system, covering the flexor digitorum superficialis (FDS) tendons in the forearm. It is vascularized by four different arteries: a constant collateral branch of the ulnar artery, and three inconstant arterial supports: from collateral branches of the superficial palmar arch, from the radial artery, and from the vasa nervorum of the median nerve. The flap is harvested from proximal to distal on the ulnar pedicle to cover the palmar soft tissue defects of the hand. A clinical application of this synovial flap is presented via a case report for covering a palmar skin defect secondary to a hand injury. The synovial flap contains a constant ulnar pedicle and could be considered a useful alternative to cover palmar soft tissue defects.

CLINICAL AND ELECTROPHYSIOLOGICAL COMPARISON OF DIFFERENT METHODS OF SOFT TISSUE COVERAGE OF THE MEDIAN NERVE IN RECURRENT CARPAL TUNNEL SYNDROME

To evaluate the clinical and electrophysiological results of 26 patients treated with either a hypothenar fat flap or a synovial flap to prevent recurrent scar compression of the median nerve after previously failed carpal tunnel decompression. A total of 26 patients underwent flap coverage as a result of a nerve tethering attributable to a position within scar; 15 were covered by a synovial flap and 11 by a hypothenar fat flap. Only patients in whom the median nerve was significantly enveloped in scar tissue were included. All candidates underwent a thorough clinical examination and nerve conduction test. The pre- and postoperative nerve conduction tests and the results of the two groups were statistically compared. The reduction rates of brachial nocturnal pain and pillar pain were 25 and 25%, respectively, in the synovial flap group and 64 and 37%, respectively, in the hypothenar fat flap group. The reduction rates of a positive Tinel's sign (25%) and a positive Phalen's test (13%) were lower in the synovial flap group compared with hypothenar fat flap coverage (55% Tinel's sign, 46% Phalen's test). Thenar atrophy and paresthesia were reduced in 44 and 62%, respectively, in the synovial flap group and in 46 and 64%, respectively, in the hypothenar fat flap group. The overall patient satisfaction (73%) and the Disabilities of the Arm, Shoulder and Hand score (31 points) appeared superior in the hypothenar fat flap group compared with the synovial flap group (56%; 37 points). Nerve conduction tests demonstrated a significant improvement when comparing the pre- and postoperative measurements in both groups. Distal motor latency decreased in the hypothenar fat flap group from 6.81 ms to 4.92 msec (P = 0.01; mean value) and in the synovial flap group from 6.04 ms to 4.43 msec (P < 0.001; mean value). Coverage by an ulnar-based hypothenar fat flap appeared to produce superior clinical results compared with coverage with synovial tissue from adjacent flexor tendons, although conclusive statistical evaluation of clinical outcomes was not possible. Further studies to confirm this are warranted.

The Synovial Flap in Recurrent and Failed Carpal Tunnel Surgery

Recurrent carpal tunnel syndrome is defined by a return of numbness after a symptom-free period after surgical decompression. The most common reason for recurrent symptoms is thought to be the formation of a constrictive scar. In this event, it seems reasonable to lay a barrier about the nerve after rerelease to try to prevent recurrent scar formation. We believe this approach is also reasonable during revision surgery for iatrogenic nerve injury. In this article, we describe the indications and technique and clinical experience using a synovial flap used to cover the median nerve after revision decompression at the wrist.

Vascularized synovial flap promoting regeneration of the cryopreserved meniscal allograft: experimental study in rabbits

AbstractThe purpose of this investigation was to evaluate whether a vascularized or free synovial flap or a fibrin clot can promote regeneration of meniscal allograft in the rabbit. Seventy-eight mature New Zealand white rabbits were used. The harvested medial meniscus for the allotransplantation was frozen and stored at –80°C for 2 weeks. After resecting the medial meniscus, an allogenic meniscus was transplanted in the anatomical position (group A). The surface of the graft was covered by a vascularized synovial flap (group B), a free synovial flap (group C), or a fibrin clot (group D). The animals were killed 4, 6, 8, 12, and 16 weeks after transplantation, and the transplants were examined by gross inspection, histology, and microangiography. Connective tissue infiltration into the matrix of the graft was found to begin at 6 weeks (2/5 menisci) and to be complete at 8 weeks (5/5 menisci) in group B, whereas it began at 8 weeks (1/5) in group A. The newly formed repair tissue developed from the synovial tissue and consisted of connective tissue at the beginning and fibrocartilage later. The fibrocartilage had appeared at 8 weeks (3/5) in group B but not yet in group A (0/5). A free flap or fibrin clot coverage resulted in delayed revascularization compared to a vascularized synovial flap, but both tended to achieve faster revascularization than the controls. We concluded that regeneration of allografted meniscus with a vascularized synovial flap occurs earlier than under other conditions. Thus, allografts with synovial implantation may be considered for management of the meniscectomized knee.

THE SYNOVIAL FLAP AS TREATMENT OF THE RECURRENT CARPAL TUNNEL SYNDROME

After an exact definition of the recurrent carpal tunnel syndrome, its treatment, as described in the literature, is presented. To cover the median nerve isolated from the extended scar tissue with a thin and well-circulated tissue, the author proposes and demonstrates the synovial flap. The follow-up of 27 cases operated since 1979 with a follow-up time between 1 month to 14 years shows 6 excellent, 16 good, 3 satisfactory and 2 bad results.

Second Look Arthroscopy After Meniscal Repair

Second look arthroscopy was performed on 46 of 137 consecutive patients who underwent arthroscopic meniscal repair. All tears were of the vertical type. Thirty-two tears were located in avascularized areas. Thirty-one patients had associated anterior cruciate ligament insufficiencies. Anterior cruciate ligament reconstructions were performed simultaneously on 26 patients. The double-needle cannula method was used in all the patients. An additional transplantation of a vascularized synovial pedicle flap to the suture site was performed on 7 tears in avascularized areas. Second look arthroscopy showed no healing in 8 patients and healing in 38. Four of the 8 unhealed tears were located in avascularized areas, and 4 had unreconstructed anterior cruciate ligament injuries respectively. All 7 patients with synovial pedicle flaps showed healing. All patients with anterior cruciate ligament reconstructions showed healing, and the healing rate was significantly higher than that of the other patients (p < 0.005). Patients with anterior cruciate ligament insufficiencies showed a significantly lower healing rate than the others (p < 0.005). In patients with tears in avascularized areas, the conventional meniscal repairs showed a lower healing rate than did the repairs with a synovial pedicle transplantation or an anterior cruciate ligament reconstruction (p < 0.005). These results suggest that the most important factors influencing meniscal healing are the presence of anterior cruciate ligament tears, ligamentous reconstruction, and vascularity of the tear site.

Meniscal repair by synovial flap transfer. Healing of the avascular zone in rabbits.

We studied repair of a longitudinal incision of the right medial meniscus in 44 rabbits after the transfer of a pedunculated synovial flap, without immobilization of the knee. The left medial meniscus was used as the control, after creating the same lesion without synovial flap. Healing was analyzed by histologic studies, including India ink perfusion after 8, 12, 24, and 48 weeks. In three quarters of the cases, the meniscus showed healing with vascularization of an originally avascular zone.

Repair of temporomandibular joint disc perforation using a synovial membrane flap in Macaca fascicularis monkeys: Light and electron microscopy studies

Previous studies have demonstrated that experimentally produced perforations in the discs of Macaca fascicularis monkeys lead to osteoarthrosis. Synovial membrane hyperplasia also was demonstrated in monkey and human joints with disc perforations. The hypothesis was advanced that a synovial flap obtained from within the affected joint would be the most appropriate tissue to repair chronic disc perforation. To test this hypothesis, four adult M fascicularis monkeys were anesthetized and 4- to 6-mm perforations were made in the posterolateral aspects of the avascular discs bilaterally. The wounds were sutured leaving the perforations open, and the animals were fed their normal diet. After 4 weeks, one joint in each monkey was reopened and a repair was performed using a double-layered flap from the synovial lining of the superior and inferior recesses. Four weeks after repair, the animals were killed and the temporomandibular joints (TMJs) were removed en bloc and decalcified. The joints were sectioned into lateral, middle, and medial sections and were photographed using a stereomicroscope and then processed for light and electron microscopy. The same processing was done to four intact joints that were used as controls. Eight weeks following perforation, the joint components showed degenerative changes consistent with osteoarthritis. Close to the perforations the disc showed loss of collagen, vacuolation of extracellular matrix, accumulation of dense proteoglycan-like material, and the appearance within the disc of type A or macrophage-like cells of the synovium. The discal tissue away from the perforation showed high cellularity and vascularity. The temporal and condylar surfaces showed denudation, fibrillation, osteophytes, and chondrocytic clustering, all characteristics of osteoarthrosis. The surgically repaired discs were intact and the articular surfaces showed no degenerative changes. Discal collagen was restored and appearance of myofibroblasts and elastogenesis were a consistent feature of the repaired disc. The vascularity of the condylar cartilage of the repaired joints appeared similar to that of embryonic cartilage. The reversibility of the degenerative alterations following discal repair in this experimental model should provide the basis for a rational and useful method for surgical repair of TMJ disc perforation using intraarticular synovial tissue.

Porous polymer implant for repair of meniscal lesions: a preliminary study in dogs

Artificial meniscal lesions extending into the avascular part of the meniscus, which do not heal by any other means, were repaired by suturing either a porous polymer implant or a synovial flap into the defect. The implant guided the ingrowth of vascular repair tissue into the defect. This fibrous tissue later on transformed into fibrocartilage. Reconstruction with a synovial flap was not successful. It appeared that healing can be achieved by implantation of a porous polymer implant in a large number of cases. Future research will be aiming at improvement of the results of meniscal repair and application of this type of polymer for repair of cartilage defects.

Experimental models to promote healing of tears in the avascular segment of canine knee menisci.

Longitudinal tears were created in canine lateral menisci and techniques were applied to induce healing by removal of a core of tissue from the periphery of the meniscus to the tear or by implantation of a vascularized synovial flap into the tear. The meniscal tears did not heal in knees that were not immobilized, and they healed poorly and sporadically in knees that were immobilized in a cast but bore some weight. However, a higher percentage of tears that were treated by the core-removal or synovial-flap technique healed when the knee was firmly immobilized and weight-bearing was prevented by the use of an external skeletal fixator across the joint for eight to twelve weeks. Neovascularization and access to a source of reparative cells appear to be important in the healing process.

An Experimental Study of Reconstructive Procedures in Lesions of the Meniscus

Reconstructive procedures were investigated in meniscal lesions in 25 rabbits. Large meniscal defects were repaired with either a synovial flap or a carbon fiber implant. Fibrous tissue healing with occasional areas of fibrocartilage occurred after both types of reconstruction. When carbon fibers were used the ingrowing fibroblasts showed directional orientation.