[The complexity of hand-surgical procedures in the context of cross-sector care concepts: a consensus recommendation of the German Society of Hand Surgery] / Die Komplexität handchirurgischer Therapien im Kontext sektorenübergreifender Versorgungskonzepte: Konsensusempfehlung der Deutschen Gesellschaft für Handchirurgie.

Overboarding politcal influence in Germany concerning medical issues has come to a new peak. The report by the IGES Institute published in 2022 made an important contribution in this regard. Unfortunately, only that part of the recommendations of this report were implemented in a new version of the contract for outpatient surgery according to Section 115b SGB V (AOP contract), that called for an expansion of outpatient surgery. In particular, those aspects that are important from a medical point of view for a patient-specific adjustment of outpatient surgery (e. g. old age, frailty, comorbidities) as well as the important structural requirements for outpatient postoperative care were included in the new AOP contract at best in a rudimentary manner. For this reason, the German Society for Hand Surgery felt compelled to give its members a recommendation as to which medical aspects must be taken into account, especially when performing hand surgery operations, in order to ensure the highest level of safety for the patients entrusted to us while performing outpatient surgery. An expert group of experienced hand surgeons and hand therapists who work in hospitals of all levels of care as well as resident surgeons was formed in order to formulate mutually agreed recommendations for action.

Arthroscopic Capsulodesis for the Treatment of Dynamic Scapholunate Dissociations.

Management of scapholunate dissociations remains a significant challenge. Open approaches suffer from a disadvantageous further impairment of the stabilizing local structures. The minimally invasive arthroscopic technique described provides reliable stability of the scapholunate interosseous ligament complex in dynamic lesions. The anatomic key structure is the dorsal capsuloligamentous scapholunate septum, which provides a mechanical connection between the scaphoid, lunate, and dorsal capsule of the wrist. Arthroscopic capsuloplasty aims to tighten and stabilize this complex structure in long term. This approach preserves the adjacent structures, namely the secondary wrist stabilizers and their neuromuscular feedback loops. With a certain degree of experience in wrist arthroscopy, the technique is reliably adaptable and reproducible.

Ulnocarpal Impaction.

Ulnocarpal impaction syndrome is a common cause for ulnarsided wrist pain caused by an abutment between the ulnar head and the lunotriquetral complex. This pain is typically triggered by load bearing and rotation of the forearm. Radiographic examination is often associated with positive ulnar variance and cysts in the lunate, edema of the ulnoproximal lunate is shown in MRI. Operative treatment aims to reduce load on the lunate, either by open ulnar shortening osteotomy or arthroscopic wafer procedure.

Composite tissue allotransplantation in Europe. Logistics and infrastructure of a centre.

BACKGROUND: Composite Tissue Allotransplantation (CTA) is a new medical field of growing importance. This paper focuses on the infrastructure and organisation of European CTA centres and discusses the differences between national health systems. MATERIAL/METHODS: Eight European centres (Valencia, Innsbruck, Munich, Lyon, Amiens, Creteil, Wroclaw, Monza) were sent with a specially-designed, standardized, 20-item questionnaire. RESULTS: Five of the eight centres returned our questionnaire: Munich, Innsbruck, Lyon, Amiens, Wroclaw. Since 1998, CTA has been performed at these centres. In both French centres and the Polish centre public funding is available in addition to the coverage provided by health insurers. In Munich the costs for a double upper-arm transplantation were Euro 150,000 with an additional Euro 50,000-70,000 per year. In Lyon the costs for a singular hand transplantation were Euro 70,000 per year and in Wroclaw (Poland) the costs for a hand or upper arm transplantation were Euro 20,000-30,000. As many as 17 different medical professions are involved in the CTA at the different centres. CONCLUSIONS: CTA is an innovative promising therapeutic tool that is based on the experiences of solid organ transplantation and profound microsurgical skills. Due to the complexity of the infrastructure, sourcing and the organisation CTA can only be successfully performed at specialized centres. A European network with an international European waiting list and a central coordination for CTA should be established. In order to advance CTA as an important tool in reconstructive surgery we must turn our attention to how the costs will be met, the legal environment for procurement of adequate donors and open ethical questions.

Non-viral genetic transfection of rat Schwann cells with FuGENE HD© lipofection and AMAXA© nucleofection is feasible but impairs cell viability.

PURPOSE: To determine transfection efficiency of FuGENE HD© lipofection and AMAXA© nucleofection on rat Schwann cells (SC). METHODS: The ischiadic and median nerves of 6-8 week old Lewis rats were cultured in modified melanocyte-growth medium. SCs were genetically transfected with green fluorescent protein (GFP) as reporter gene using FuGENE HD© lipofection and AMAXA© nucleofection. Transfection rates were determined by visualization of GFP fluorescence under fluorescence microscopy and cell counting. Transfected cell to non-transfected cell relation was determined. RESULTS: Purity of Schwann cell culture was 88% as determined by immunohistologic staining. Transfection rate of FuGENE HD© lipofection was 2%, transfection rate of AMAXA© nucleofection was 10%. With both methods, Schwann cells showed pronounced aggregation behavior which made them unfeasible for further cultivation. Settling of Schwann cells on laminin and poly-L-ornithine coated plates was compromised by either method. CONCLUSION: Non-viral transfection of rat SC with FuGENE HD© lipofection and AMAXA© nucleofection is basically possible with a higher transfection rate for nucleofection than for lipofection. As cell viability is compromised by either method however, viral transfection is to be considered if higher efficiency is required.

Efficacy of various durations of in vitro predegeneration on the cell count and purity of rat Schwann-cell cultures.

The efficacy of Schwann-cell cultivation can be enhanced by in vitro predegeneration of the harvested cells compared to immediate culture. The aim of this study was to improve Schwann-cell culture efficacy by comparing three different durations of predegeneration. The sciatic and median nerves of 6-8-week-old Lewis rats were harvested and subjected to either 2-day, 7-day, or 14-day predegeneration in Dulbecco's Modified Eagle's Medium supplemented with 10% fetal calf serum and 1% Penicillin/Streptomycin. Afterward, tissue was enzymatically dissociated and placed in a modified melanocyte growth medium. The cell count was determined immediately after dissociation while the cell purity was determined one subculture/trypsinization cycle later after cell attachment to the culture plate by means of optical microscopy and immunocytochemistry. Particular attention was then paid to the Schwann-cell-to-fibroblast relation. The cumulative cell count in the culture was 5.8 x 10(5) for 2-day, 1.12 x 10(6) for 7-day, and 1.48 x 10(6) for 14-day predegeneration. The culture purity was approximately equal for 2- and 7-day predegeneration (88% Schwann cells, 12% fibroblasts after 2 days; 85% Schwann cells, 15% fibroblasts after 7 days). After 14 days, however, cell cultures were significantly debased by fibroblast proliferation (57% Schwann cells, 43% fibroblasts). In vitro predegeneration is a particularly suitable procedural method to increase the cultural Schwann-cell yield. The number of cultivated rat Schwann cells is doubled by 7-day in vitro predegeneration in comparison to 2-day predegeneration. After 14-day predegeneration, however, the culture is significantly debased by fibroblasts. Therefore, 7-day in vitro predegeneration is an advisable predegeneration period.

Functional recovery after implantation of artificial nerve grafts in the rat- a systematic review.

PURPOSE: The aim of this study was to compare functional data of different nerve-gap bridging materials evaluated in rat experiments by means of a systematic review. MATERIALS AND METHODS: A systematic review was conducted, searching MEDLINE, HTS and CENTRAL to identify all trials evaluating functional recovery of artificial nerve conduits in the rat model. RESULTS: There was a trend towards a favourable outcome of conduits coated with Schwann-cells compared to the plain synthetics. Histomorphometry, electrophysiology and muscle-weight correlated poorly with functional outcome. CONCLUSION: Schwann-cell coated conduits showed promising results concerning functional recovery. Further standardization in outcome reporting is encouraged.

Local administration of DFO-loaded lipid particles improves recovery after end-to-end reconstruction of rat median nerve.

PURPOSE: The improvement of regeneration and functional recovery after peripheral nerve injury is a major challenge in neurosurgery. Although microsurgical techniques for nerve reconstruction have seen great advancements over the last years, the clinical outcome with patients is often unsatisfactory. The aim of the present study was to investigate if administration of the iron chelator Deferroxamine (DFO), can improve postoperative outcome in the rat median nerve reconstruction model. METHODS: After complete transection, the right median nerve was repaired by end-to-end neurorrhaphy. The suture site was wrapped by a 1-cm-long external jugular vein segment, either empty or filled with DFO-loaded lipid particles (Perineurin or with a vehicle (unloaded lipid particles) alone. Functional testing was carried out weekly by means of the grasping test. At the time of withdrawal, 12 weeks post-operatively, muscle tropism recovery was assessed by weighing flexor digitorum sublimis muscle that is innervated by the median nerve only. Before harvesting of the nerve specimens electrophysiological analyses were performed with measuring the latency, the threshold and the conduction velocity. Finally, the repaired nerves were withdrawn for immunocytochemistry with a neurofilament antibody and axon quantitative morphology. RESULTS: The comparison between the groups showed that intraoperative application of the DFO-loaded lipid particles at the neurorrhaphy site led to a significant increase in the density of regenerating axons as well as to an accelerated recovery of both muscle tropism and motor function. The electrophysiological results demonstrated a decrease of the threshold, a lower latency, and a higher conduction velocity in the Perineurin-treated animals. CONCLUSIONS: The results of the present study suggest that local administration of Perineurin might have a therapeutic potential for improving the postoperative outcome after microsurgical nerve reconstruction in patients.

Long nerve gaps limit the regenerative potential of bioartificial nerve conduits filled with Schwann cells.

PURPOSE: Recently we successfully used a conduit of epsilon-caprolactone-co-trimethylene carbonate filled with Schwann cells (SC) across a 20 mm gap in a rat median nerve. In this study we applied the tubes with SC across a 40 mm gap in order to analyse the regenerative potential of the tubes in long nerve defects. METHODS: To augment the nerve defect a cross-chest procedure was used and the tubes were implanted with injected isogeneic SCs inside (group 3). Both ulnar nerves were used for a 40 mm autograft (group 2). For control group non-operated animals were used (group 1). The grasping test, histology (S-100, PAM), electrophysiology, and the muscle weight were used to assess regeneration. RESULTS: After 12 months, grasping was seen only in three animals of group 3 (3.6 g [95% CI: 0 to 7.6 g]). However, in group 2 all rats had a partial functional regeneration (42.8 g [95% CI: 39.1 to 46.6 g]). The grasping force of the non-operated animals (group 1) was 240.9 g [95% CI: 237.2 to 244.7 g] at the time. Histology from group 3 confirmed an irregular arrangement of fibres in contrast to more organized structures in group 2. Electrophysiology in group 3 displayed potentials only in the three animals with functional regeneration. In group 2 all animals exhibited potentials. A significant decrease of muscle weight was observed in groups 2 and 3, most prominent in the latter. CONCLUSION: Regeneration was not successful across the 40 mm gap using the applied tube in combination with SC. For future experiments further consideration should be taken in optimizing the cellular and material components that are critical for a successful application to overcome very large nerve gaps.

Memantine treatment of complex regional pain syndrome: a preliminary report of six cases.

OBJECTIVES: Recent studies have confirmed the contribution of the central nervous system (CNS) to the pathogenesis of Complex Regional Pain Syndrome (CRPS), because animal models of neuropathic pain syndromes demonstrate an overexpression of N-methyl-D-aspartate-receptors in the CNS. The aim of this work was to study the influence of a central acting drug-the N-methyl-D-aspartate receptor antagonist Memantine-in patients with CRPS of one upper extremity. Here we present the results of 6 patients treated with Memantine for 8 weeks. METHODS: All patients developed CRPS after traumatic injury to one upper extremity. To document changes during the study, levels of pain were measured after clenching the hand using a numeric pain intensity scale ranging from 0 (no pain) to 10 (maximum pain). Motor symptoms were documented for the fingers (fingertips to palm and fingernails to table) and the wrist (flexion/extension). Furthermore, the force was analyzed using a JAMAR-Dynamometer and a Pinchmeter. For assessment of central changes, functional magnetic resonance imaging and magnetoencephalography were used to further document the results of other experiments in 1 patient. Autonomic changes were photographed and pictures were compared before and after treatment with Memantine. RESULTS: Six months after treatment with Memantine, all patients showed a significant decrease in their levels of pain which coincided with an improvement in motor symptoms and autonomic changes. The functional magnetic resonance imaging and magnetoencephalography results provided evidence of cortical reorganization [changes in somatotopic maps in the primary somatosensory cortex (S1)]. These changes returned to a cortical pattern comparable to the unaffected side after treatment with Memantine. DISCUSSION: Based on these first results, the use of Memantine for treatment of CRPS seems promising and supports the hypothesis of a CNS contribution to the pathogenesis and maintenance of neuropathic pain syndromes.

Neuroma formation in a rat median nerve model: influence of distal stump and muscular coating.

BACKGROUND: The purpose of this study was to investigate neuroma formation in a rat median nerve model. METHODS: In three groups, the median nerve was exposed and a gap was created. In the first group, a short gap of 1 cm (n = 12) was created; in the second, a long gap of 2 cm (n = 12) was created in the nerve. Another group was used to analyze the development of neuroma formation when the proximal stump was buried in adjacent muscle with an additional gap of 2 cm (n = 12). The use of different lengths should allow one to gain information about dilution effects of distal stump factors that may contribute to neuroma formation. Nine months later, specimens were gathered and histologically analyzed. The cross-sectional areas of neuromas were measured and the neural/connective tissue ratios were estimated. RESULTS: The cross-sectional areas demonstrated that neuroma formation was significantly higher in the short-gap group than in the long-gap group, and smallest in the muscle-covered group. The percentage of neural tissue was highest in the muscle-covered and long-gap groups and lowest in the short-gap group. CONCLUSIONS: These results demonstrate an association between neuroma formation and distal stump distance. This observation may be explained by the factors originating from the distal stump that were blocked when the proximal nerve stump was completely buried in the muscle. For clinical application, the authors recommend not only burying the proximal stump in a muscle but also surgically augmenting the gap between the proximal and distal stumps.

Sonography of brachial plexus traction injuries.

OBJECTIVE: Our purpose was to evaluate the feasibility of sonography in identifying nerve abnormalities in patients with traction injury of the brachial plexus. CONCLUSION: Sonography of the brachial plexus was technically feasible, although the entire brachial plexus could not be evaluated. Sonography appears to be a useful bedside imaging technique for assessing brachial plexus injury. The potential of sonography as a complementary diagnostic tool in the evaluation of these patients warrants further investigation.

Cross-chest median nerve transfer: a new model for the evaluation of nerve regeneration across a 40 mm gap in the rat.

A new animal model for the study of nerve regeneration in rats across a 40 mm gap between both median nerves is described. For autologous grafting, the ulnar nerves were dissected and sutured together. From the left median nerve, they were transplanted across the chest to the right median nerve. Animals having undergone this operation were observed for 12 months and periodically assessed using the grasping test and measurements of body-weight. For histological analysis rats were sacrificed after this period and axon counts were determined at the suture points of operated animals and in the median nerve of non-operated animals. Functional recovery could be seen, although partially, beginning as early as the fifth postoperative month, as demonstrated by the grasping test. Quantification of the number of axons demonstrated axonal regeneration across all three coaptation points. This model provides a new approach for analysis of long distance peripheral nerve regeneration without impairment of behaviour.

Nerve regeneration across a 2-cm gap in the rat median nerve using a resorbable nerve conduit filled with Schwann cells.

OBJECT: In a rat model, nerve regeneration was evaluated across a 2-cm defect in the median nerve by using a resorbable artificial nerve conduit. The aim of this study was to develop an artificial, biocompatible nerve guide to induce regeneration in the peripheral nervous system. METHODS: The authors compared a nerve conduit of trimethylenecarbonate-co-epsilon-caprolactone (TMC/CL) filled with autologous Schwann cells with both an empty hollow conduit and an autologous nerve graft. Animals that did not undergo surgery served as the control group. Nerve regeneration was evaluated with the grasping test, histological analysis of the nerve, muscle weight analysis (flexor digitorum superficialis muscle), and electrophysiological examination. After an observation period of 9 months, regeneration occurred only in animals that had received an autologous graft or a Schwann cell containing nerve conduit. No signs of regeneration were found in animals supplied with the empty conduit. CONCLUSIONS: Results of this study reveal the important role of Schwann cells in the regeneration process across a 2-cm defect in the rat median nerve. Furthermore, Schwann cell-filled nerve conduits induced functional recovery, as demonstrated in the grasping test, that was comparable with that of the autologous graft 9 months after implantation.

Management of complete obstetric brachial plexus lesions.

From 1978 to 2002, the authors have operated on 723 babies for obstetric brachial plexus repair. Complete paralyses and associated root ruptures and avulsions are severe, and the results cannot be evaluated before the end of growth. A series of 73 patients operated on from 1978 to 1994 were followed with a mean follow-up of 6.4 years. Secondary operations (mainly on the shoulders) were necessary 123 times. Although the results show that the shoulders and elbows did not do as well as in upper-type lesions, the results at the level of the hand were encouraging, showing 75% useful results after 8 years, even in patients with avulsion injuries of the lower roots. These results demonstrate the usefulness of early exploration and repair of the obstetric plexus.

Vascular dominance in the forearm.

The dominance of the radial or ulnar artery at the forearm level and their contributions to the circulation of the hand remain a matter of contention. Therefore, the authors proposed to investigate the predominance of one of these arteries first by anatomic studies on 40 fresh cadaver upper extremities, and then by dynamic studies. The dynamic studies included color Doppler sonography in 22 individuals (44 hands) and five-channel plethysmography in 40 individuals (40 right hands). It was found that the ulnar artery is dominant at the elbow, but after originating its collateral branches, the radial artery becomes the dominant artery in the distal forearm and, consequently, constitutes the major source of vascularization to the hand. The ulnar artery is rarely dominant at the forearm level and is physiologically less important. Therefore, there is no hemodynamic reason to prefer the radial artery to the ulnar artery for any invasive maneuvers.

Continuous brachial plexus analgesia and NMDA-receptor blockade in early phantom limb pain: a report of two cases.

OBJECTIVE: To provide a mechanism-based acute pain management strategy for early phantom limb pain following traumatic amputations and to collect first evidence of its acute and potentially preventative effects on the formation and maintenance of phantom limb pain. The combination of continuous brachial plexus analgesia and prolonged block of N-methyl-D-aspartate (NMDA) receptors over 4 weeks aimed to attenuate peripheral and central sensitization, currently thought to be substantially involved in establishing and maintaining phantom limb pain. CASE REPORT: Two patients, after traumatic upper limb amputations and early phantom limb pain, were treated on the second and fifth day following amputation by continuous brachial plexus analgesia with ropivacaine 0.375% (30 ml for the initial block, continuous infusion rate = 5 ml/h) for 5 (Patient 1) and 9 days (Patient 2). Both patients received oral memantine (a noncompetitive NMDA-receptor antagonist) in increasing doses from 10 to 30 mg/d over a 4-week period. Ropivacaine only produced minor motor block, with almost unimpaired motor function. Memantine was well tolerated and no relevant side effects were observed. In both patients the treatment prevented the establishment of phantom limb pain, which did not reappear during follow-up of 1 year. CONCLUSIONS: The combination of long-term regional analgesia with prolonged block of NMDA receptors might be effective for treatment and prevention of phantom limb pain following traumatic amputations. The absence of clinically relevant side effects, together with maintained motor function suggests this treatment to be a promising preventive strategy for phantom limb pain following traumatic amputations.