Osteoarthritis (OA) is a highly prevalent degenerative joint disorder characterized by joint pain and physical disability. Aberrant subchondral bone induces pathological changes and is a major source of pain in OA. In the subchondral bone, which is highly innervated, nerves have dual roles in pain sensation and bone homeostasis regulation. The interaction between peripheral nerves and target cells in the subchondral bone, and the interplay between the sensory and sympathetic nervous systems, allow peripheral nerves to regulate subchondral bone homeostasis. Alterations in peripheral innervation and local transmitters are closely related to changes in nociception and subchondral bone homeostasis, and affect the progression of OA. Recent literature has substantially expanded our understanding of the physiological and pathological distribution and function of specific subtypes of neurones in bone. This review summarizes the types and distribution of nerves detected in the tibial subchondral bone, their cellular and molecular interactions with bone cells that regulate subchondral bone homeostasis, and their role in OA pain. A comprehensive understanding and further investigation of the functions of peripheral innervation in the subchondral bone will help to develop novel therapeutic approaches to effectively prevent OA, and alleviate OA pain. Cite this article: Bone Joint Res 2022;11(7):439–452

Between 1988 and 1998, a total of 12 patients (6 men and six women, of average age 36 years) underwent surgery for schwannoma of the peripheral nerves of the upper extremity. The incidence according to the involved nerve was analyzed and the follow-up results and complications after surgical treatment were reviewed. The median nerve was most frequently involved (6 cases), followed by the ulnar nerve (4 cases) and the radial nerve (2 cases). The average duration of symptoms was 2 years (3 months-8 years). Pain or painful paresthesias were usually the main complains. None of the patients suffered from Recklinhausen’s disease. Magnetic resonance imaging is the preferred exploration technique, particularly useful in case of deep tumor. EMG studies were carried out in all patients. Preservation of nerve continuity is the underlying goal of the therapeutic strategy. Marginal excision was performed in all cases. The tumors were extricable displacing the nerve fiber bundles without penetrating into the bundle itself and it was possible thus to be resected without interrupting the nerve continuity. Postoperatively, 7 patients were pain free, while 5 improved. Neurological deficits were favourably influenced by the operation. Out of 4 patients with motor deficits 3 had complete and 1 had partial recovery. Three out of 6 patients with sensory deficits had complete recovery, 2 remained unchanged, while 1 worsened. One patient developed new motor and another one new sensory deficits. New deficits developed predominantly in patients with large tumorsor longstanding symptoms. There was no reccurence or malignant transformation until the average of 52 months of follow-up

Purpose of the study: Benign tumors of peripheral nerves are exceptional. Schwannomas predominate. Most tumors are revealed by tumefaction or pain over a nerve trajectory. The risk of degeneration is very low. Magnetic resonance imaging is the exploration of choice. The risk of sequelae or recurrence must nevertheless be determined with precision. We reviewed our experience with 93 benign tumors of peripheral nerves to search for factors predictive of prognosis. Material and methods: This retrospective analysis included patients seen between 1979 and 2004. We collected a series of 89 patients, 41 women and 48 men, mean age 48 years, age range 18–80, with 93 benign tumors. Mean time from symptom onset (pain) to diagnosis was 20 months. The patients consulted for pain (n=78), presence of a mass (n=79) or both (n=66). Percussion produced paresthesia in 54 patients. Pre-operative magnetic resonance imaging was available for 45 patients. The same surgeon performed nerve microsurgery in all patients. A prior procedure had been performed in another institution for 23 patients. The tumors were: schwannoma (n=74), neurofibroma (n=14), plexiform neurofibroma (n=3), angiolipoma (n=1) and intranervous lipoma (n=1). Mean tumor size was 31 mm (range 7–120 mm). Tumors were located in the brachial plexus (n=13), the upper limb (n=29), the trunk (n=1) and the lower limb (n=50). Complete resection was achieved in 83 cases, with removal of a non-stimulatable fascicle in 50 cases and a motor fascicle in. 4. Nerve repair was required for 11 cases: 5 by direct suture and 6 with grafts. Resection was impossible for 4 tumors treated by neurolysis, decompressive epineu-rotomy, biopsy and interfascicular dissection. Results: Mean follow-up was 96 months (range 3–300). Outcome was very good for 42, good for 25, fair for 8 and poor for 5 (all seen secondarily). Nine patients were lost to follow-up. There were no cases of recurrence. Discussion: Microsurgical procedures are necessary for resection of nerve tumors in order to preserve the fascicles and thus function. Unresectable tumors and secondary grafts yield les satisfactory results, in our series and in the literature. Similarly, the duration of the symptoms and the size of the tumor increase the risk of operative difficulty and sequelae. Despite high-performance imaging techniques, surgery is the only sure way to establish certain diagnosis

Solitary tumors of the peripheral nerves are uncommon and found to be benign in 90 p. 100 of the cases. They develop from the elements constituting the nerve and are generally schwannomas (80 p. 100). Other tumors are much more exceptional and exhibit wide histological variability. The diagnosis of a tumor of the peripheral nerve must be envisaged for all cases with tumefaction or pain on the path of a nerve exacerbated at percussion. Magnetic resonance imaging is the preferred exploration technique, particularly useful in case of a deep tumor. Preservation of nerve continuity is the underlying goal of the therapeutic strategy, irrespective of the type of tumor. Extricable tumors are to be distinguished from inextricable tumors. Extricable tumors (schwannomas, intranervous lipomas) displace nerve fiber bundles without penetrating into the bundle itself and can thus be resected without interrupting nerve continuity. Prognosis is excellent if no recurrence or degeneration occurs. In case of persistent symptoms, a new exploration may be required to search for other localized tumor(s) unperceived at the first procedure. Inextricable tumors (solitary neurofibromas, hemangiomas of the Schwann sheath, neurofibrolipomas) infiltrate the structural elements of the nerve fibers making complete excision impossible without altering the nerve fibers. Epineurotomy (associated with an interfascicular biopsy for pathology examination) allows decompression and can often provide symptom relief although moderate paresthesia may persist. Patients must be informed of this possibility prior to surgery. Any recent and rapidly evolving modification in the clinical findings is suggestive of recurrence and should be followed by revision exploration. Malignant degeneration has not been observed in solitary tumors to our knowledge. Our own experience with 51 cases is generally in agreement with reports in the literature

Purpose: Isolated tumours of the peripheral nerves are exceptional and benign in 90% of the cases. They develop from the constitutive elements of the nerve and correspond to schwannomas in 80% of cases. Other tumours are much more rare and exhibit wide histological variability. Material and methods: Fifty-one patients were reviewed at mean 4.6 years. Forty-one had a resectable tumour: schwannoma (n=39), intranervous lipoma (n=2). Ten an unresectable tumour: solitary neurofibroma (n=5), peri-nervous hemangioma (n=3), neurofibrolipoma (n=2). We detailed the type of lesion, diagnostic elements, and results of complementary explorations. Enucleation was performed for resectable tumours. Epineurotomy for decompression with systematic interfascicular biopsy was performed in the event of an unresectable tumour. Results: Postoperative neurological deficits were exceptional and transient. In a first case, prognosis was excellent due to the absence of recurrence or degeneration. In the second, neurological disorders persisted but decreased (paraesthesia). The course remained stable. Discussion: Our findings are in line with reports in the literature. The diagnosis of nerve tumour should be entertained in the event of tumefaction along a nerve trajectory or if palpation triggers pain. MRI is the most powerful complementary exploration, particularly for deep tumours. The nature of the tumour, its benignity, and the possibility for resection can be suspected on the basis of clinical and complementary findings, but surgery and pathology examination of the surgical specimen are required for confirmation. Preservation of nerve continuity is the key to the therapeutic approach. For resectable tumours, exceptional persistence of symptoms should be followed by a new exploration to search for small unrecognised tumour(s) at the same operative site. For all other cases, recent and rapid changes in the clinical presentation is a sign of recurrence and requires appropriate intervention. To our knowledge, malignant degeneration has never been observed. Conclusion: First-intention resection of a nerve with a nerve tumour is never indicated

Introduction and aims

We present a series of patients who have had secondary reconstruction of war injuries to the upper and lower limbs, sustained during the Iraq and Afghanistan conflicts.

Introduction

We present a series of patients who have had secondary reconstruction of war injuries to the upper and lower limbs, sustained during the Iraq and Afghanistan conflicts.

The concept of non-anatomic reversed arthroplasty is becoming increasingly popular. The design medializes and stabilizes the center of rotation, and lowers the humerus relative to the acromion, and lengthens the deltoid muscle up to 18%. Such a surgically created global distraction of muscles is likely to affect nervous structures. When nerves are stretched up to 5–10%, axonal transport and nerve conduction starts to be impaired. At 8% of elongation, venous blood flow starts to diminish and at 15% all circulation in and out of the nerve is obstructed. [. 1. ] To understand nerve dynamics following reversed arthroplasty, we investigated nerve strain and excursion in a cadaver model. In a formalin-embalmed female cadaver specimen, the brachial plexus en peripheral upper limb nerves were carefully dissected and injected with an iodine containing contrast medium. At the same time 1.2 mm-diameter leaded markers were implanted at topographically crucial via points for later enhanced recognition on CT reconstructions. After the first session of CT scanning a plastic replica of the Delta reversed shoulder prosthesis® was surgically placed followed by re-injection of the plexus with the same solution. The preoperative and the postoperative specimen were studied using a helical CT scan with a 0,5 mm slice increment. The Mimics® (Materialise NV, Belgium) software package was used for visualization and segmentation of CT images and 3D rendering of the brachial plexus and peripheral nerves. After surgery, there was an average increase in nerve strain below physiologically relevant amplitudes. In a few local segments of the brachial plexus an increase in nerve strain exceeding 5–10 % was calculated. The largest increase in strain (up to 19%) was observed in a segment of the medial cord. These results suggest there might be a clinically relevant increase in nerve strain following reversed shoulder arthroplasty

Introduction. External fixation (EF) devices are commonly used in the management of complex skeletal trauma, as well as in elective limb reconstruction surgery for the management of congenital and acquired pathology. The subsequent removal of an EF is commonly performed under a general anaesthetic in an operating theatre. This practice is resource intensive and limits the amount of operating theatre time available for other surgical cases. We aimed to assess the use of regional anaesthesia as an alternative method of analgesia to facilitate EF removal in an outpatient setting. Materials & Methods. This prospective case series evaluated the first 20 consecutive cases of EF removal in the outpatient clinic between 10/06/22 to 16/09/22. Regional anaesthesia using ultrasound-guided blockade of peripheral nerves was administered using 1% lidocaine due to its rapid onset and short half-life. Patients were assessed for additional analgesia requirement, asked to evaluate their experience and perceived pain using the Visual Analogue Scale (VAS). Results. Twenty patients were included in the study. The mean age was 46.6 years (range 21–85 years). Two thirds were male patients (N=13). Post procedure all patients indicated positive satisfaction ratings, each participant responding as either ‘satisfied’ (N=4), ‘very satisfied’ (N=15) or ‘highly satisfied’ (N=1). In addition, 85% of participants reported they would opt for this method of EF removal in future should it be necessary. VAS for pain immediately following completion of the procedure was low, with an average score of 0.45 (range 0–4), where a score of 0= ‘No pain’, and 10 = ‘worst pain possible’. Conclusions. We present the first description of outpatient EF removal using sole regional anaesthesia, with a prospective case series of 20 EF removed in fully awake patients. This novel technique is cost-effective, reproducible, and safe. This not only reduces the burden of these surgical cases on an operating list but also improves patient experience when compared to other forms of conscious sedation. By eliminating the use of Entonox and methoxyflurane for sedation and analgesia, this project demonstrates a method of improving environmental sustainability of surgery, anaesthesia and operating theatres

Invasive intraneural electrodes implanted in peripheral nerves are neural prosthetic devices that are exploied to control advanced neural-interfaced prostheses in human amputees. One of the main issues to be faced in chronic implants is represented by the gradual loss of functionality of such intraneural interfaces due to an electrical impedance increase caused by the progressive formation of a fibrotic capsule around the electrodes, which is originally due to a nonspecific inflammatory response called foreign body reaction (FBR). In this in vitro work, we tested the biocompatibility and ultra-low fouling features of the synthetic coating - poly(ethylene glycol) (PEG) - compared to the organic polymer - zwitterionic sulfated poly(sulfobetaine methacrylate) (SBMA) hydrogel - to prevent or reduce the first steps of the FBR: plasma protein adsorption and cell adhesion to the interface. Synthesis and characterization of the SBMA hydrogel was done. Preliminary biocompatibility analysis of the zwitterionic hydrogel, using hydrogel-conditioned medium, showed no cytotoxicity at all vs. control. We seeded GFP-labelled human myofibroblasts on PEG- and SBMA hydrogel-coated polyimide surfaces and evaluated their adhesion and cell viability at different time-points. Because of the high hydration, low stiffness reflecting the one of neural tissue, and ultra-low fouling characteristics of the SBMA hydrogel, this polymer showed lower myofibroblast adhesion and different cell morphology compared to adhesion controls, thereby representing a better coating than PEG for potentially mitigating the FBR. We conclude that soft SBMA hydrogels could outperform PEG coatings in vitro as more suitable dressings of intraneural electrodes. Furthermore, such SBMA-based antifouling materials can be envisioned as long-term diffusion-based delivery systems for controlled release of anti-inflammatory and anti-fibrotic drugs in vivo

After big loos of substances of peripheral nerves, in order to connect proximal with distal stump, it is possible to use, in alternative to autologous grafting, different kind of conduits. The chitosan conduit and the muscle in vein technique showed very good results in pre clinical and clinical settings. We compared in this study the efficacy of empty chitosan conduit versus chitosan conduit enriched with fresh muscle fibbers (MIT) to improve peripheral nerve regeneration. The median nerve of rat was repaired by means of empty chitosan conduit or MIT (nerve gam 6mm, conduit length 10 mm). As control group we used auto grafting technique. We performed analysis at short term (7,14,28 days) and at long term (12 weeks) in order to register bimolecular modification (quantitative real time PCRand western blot), morphological modification (optic and electronic microscope) and functional changing (grasping test). Bimolecular analysis showed that muscle fibbers produced and released Neuregulin1, needed for regeneration and activity of Schwann cells. Otherwise also the autograft product Neuregulin1, instead no production was observed in empty conduit. So muscle fibbers compensate this fact. Morphological analysis showed that the first myelinc fibbers appear in MIT after 14 days, but not in empty tube. The results of our work are very interesting because can merge the easiness of the implantation of chitosan tube and the efficacy of fresh muscle fibbers, as previously demonstrated by muscle in vein technique. From a clinical point of view this procedure could be an alternative to auto grafting that is nowadays the gold standard for nerve repair, but present soma disadvantages

Scar tissue formation between nerve and surrounding muscle is one of the most undesired occurrence in nerve surgery In order to prevent scar tissue apposition after surgery, a lot of biocompatible products have been developed and tested first of all on animal models and then in surgical practice. we tested the efficacy of a CMC-PEO gel in reduction of perineural scar tissue formation in a mice model and in a small group of patients. We performed surgical procedures on 26 male mices The animals were randomized into three groups. In each group the muscular bed of sciatic nerve was burned with diathermocoagulator. In treated group we applied the tested gel in order to reduce the post surgical scar. After 3 weeks the strenght of the scar was studied using a specific tool. Also histologic analysis was performed. We also reported the results of CMC-PEO gel on 8 patients who underwent surgical decompression of peripheral nerves affected by recurrent compressive syndrome. The biomechanical analysis showed that gel application strongly reduces scar tissue. The difference between not treated and treated group was statistically significative. The histological analysis confirmed this data showing a cleavage plan between scar tissue and sciatic nerve. In patients we monitored VAS pre and post operative and we described reduction from 8 to 1 in 6 patients and from 6 to 1 in two patients. In conclusion, our study proves the efficacy in animal models of Dynavisc in scar tissue formation prevention and discloses the absolute security and biocompatibility of this products. Moreover also the small sample of patients showed the safety of this product on human, and proved its efficacy on recurrent nerve compression syndrome associated with neurolysis

Purpose of the study: Injury to peripheral nerves are common. Excessive tension on the suture can be a source of connective tissue reaction and ischemia unfavourable for nerve regeneration. A nerve graft is usually proposed to avoid this problem. The technique we propose was inspired by the one reported by De Medinacelli of which it reproduces solely the principle of distant recruitment. Material and methods: We used an aponeurotic platform or a hemitendinous platform harvested at the site of the injury. Distant anchorage was sutured with a 7/O thread. The two nerve ends were brought together by rolling the aponeurotic platform around a fine forceps. The section cut was abutted with 10/0 sutures. Results: This method has been used in 42 patients since 1995 and was preceded by an experimental phase in the rat. It has allowed us to abut nerve ends retracted up to 2.5 cm for large nerve trunks. Preliminary results are globally similar to those of an epiperineural suture or a nerve graft, depending on the case. Discussion: This technique avoids the complexity of the princeps method of De Medinacelli. It is also much less costly. It also broadens potential indications for direct suture and reduces the need for nerve grafts

Magnetic Resonance Imaging (MRI) is the cornerstone investigation for cervical disc disease (CDD). However, MRI changes suggestive of CDD are found in people above forty, even in asymptomatic healthy individuals [1]. Mere presence of MRI changes of CDD does not exclude the presence of concomitant extra-foraminal pathology. No study design. We present here a series of three cases where use of ‘high resolution ultrasound’ has allowed accurate diagnosis of concomitant extra-foraminal pathology in patients with MRI-proven CDD. The three cases were acute neuropraxia of aberrant C5 nerve root, anterior interossous nerve compression due to pseudo-aneurysm of brachial artery and ‘acute brachial neuritis’ respectively. No outcome measure. Use of diagnostic high resolution ultrasound revealed accurate diagnosis of concomitant extra-foraminal pathology in all three cases. The cases with acute neuropraxia and acute brachial neuritis recovered with conservative treatment. Pseudo-aneurysm was treated successfully with surgery. High resolution ultrasound of the brachial plexus and peripheral nerves may be useful in following scenarios to identify an extra-foraminal pathology: (1) when symptoms and signs are out of proportion to the MRI findings of CDD; (2) when there is obvious discordance between MRI and nerve conduction findings; (3) where an entrapment neuropathy is suspected but the site of nerve lesion cannot be located

This study documents the gross and histologic structure of the infrapatellar plica, and fat pad, and adds to an earlier report to the COA. The important new findings are that the femoral attachment of the plica is an enthesis, and that the plica itself is. This study seeks to demonstrate that the structure of the fat pad (FP) and infrapatellar plica (IPP) is that of an enthesis organ. Twelve fresh frozen cadaver knees, each with an IPP, were dissected and the gross anatomic features recorded. The IPP and FP were harvested for study. Representative histologic sections were prepared on tissue fixed in 10% neutral buffered formalin, embedded in paraffin, cut at 4 microns on a rotatory microtome. Staining techniques included hematoxylin and eosin, Masson's trichrome, elastic stain and S100. Appropriate decalcification of sections of the femoral insertion of the IPP was performed. All sections were examined by light microscopy at low, medium and high power. IPP types included 8 separate, 1 split, 2 fenestrated, and one vertical septum. The origin of the IPP is a fibrous arc arising from the apex of the notch separate from the margin of the articular cartilage. This attachment site is the instant centreof rotation of the IPP and FP; they are thus not isometric. The central zone of the IPP consists of a mix of connective tissue types. Representative sections taken of the femoral attachment of the IPP display a transition zone between dense fibrillar collagen of the IPP, then fibrocartilage and cortical bone similar to a ligament attachment site or enthesis. The central plica histology is composed predominantly of dense regular connective tissue with variable clear space between the collagen bundles, and is thus ligamentous. There is abundant elastase staining throughout, as well as crimping of the collagen suggesting capacity for stretch. S100 staining demonstrates nerves around and in the substance of the IPP. The central body shows lobulated collections of mature adipose tissue admixed with loose connective tissue, containing abundant small peripheral nerves and vessels (all showing crimping and redundancy), merging with the dense fibrous tissue of the IPP. The FP is highly innervated, deformable, and fibro-fatty. Its histology shows lobules of fat, separated by connective tissue septa, which merge with the synovial areolar membrane surrounding the FP. The linked structures, IPP, central body, and FP occupy the anterior compartment, and function as an enthesis organ: the IPP tethers the FP via the central body and together they rotate around the femoral origin of the IPP. They are not isometric, and must stretch and relax with knee motion. The histology correlates with this requirement. The origin of the IPP is an enthesis, a new observation. Elastase staining, redundancy of vessels and nerves, crimping and redundancy of the dense connective tissue all reflect the requirement to deform. The fat pad merges with the central body, both highly innervated space fillers, tethered by the IPP, which is a non-isometric ligament, also containing nerves. The important clinical significance of these structures is that release of the IPP at the origin reuces or eliminates anterior knee pain in most

Objective: This study was performed to review the current treatment and outcome of extra abdominal fibromatosis in our hospital, supplemented by a current review of the literature. Method: A retrospective study of 72 patients with fibromatosis seen at the Royal National Orthopaedic Hospital (RNOH) between 1980 and 2009 was performed. Patients were identified using the databases at the peripheral nerves injury (PNI) unit and the histopathology department. Medical and radiological records were reviewed. Results: There were 72 patients treated at the Sarcoma and PNI units. 40 patients were primary referrals, and 32 more had operations at the referring hospital. An operation was not carried out in 5 patients. 48 patients were treated by operation alone and this was supplemented by adjuvant therapy in 19 patients. Recurrence was seen in 24 (50.0%) of the operation alone group and 10 (52.6%) in the operation and adjuvant therapy group. The rate of recurrence was lower with complete excision. However, complete excision was impossible in some cases because of extension into the chest or spinal canal, or involvement with the axial vessels and lumbosacral or brachial plexus. Conclusion: We suggest that operative excision should seek to preserve function and that supplementary adjuvant therapy may reduce the risk of recurrence, although excision margin appears to be the most important factor. The aggressive, infiltrative behaviour of deep fibromatoses and the associated genetic mutations identified, clearly distinguish them from the superficial fibromatoses and makes their treatment more difficult and dangerous, especially where vital structures are involved. We agree with the recent recommendation that these lesions should be treated in regional soft tissue sarcoma units

Introduction: The presence of atypical muscle groups especially in sportsmen population is one of the causes of ulnar nerve entrapmnet. To treat this problem a close cooperation in between neurophysiologist, US-diagnost, surgeon and physiotherapist is mandatory. The inching (short segment study – SSS) of the peripheral nerves was introduced for testing the ulnar neuropathy at the elbow (UNE). The conventional fractionated ulnar nerve conduction studies localize the lesion only approximately to the elbow region, should be followed by inching of the ulnar nerve at the elbow. Dynamic, functional US also precise the character and localise the lesion and region of mechanical obstacles for the nerve. These methods can disclose the degree of focal conduction block or pinpoint the region of focal slowing, giving complementary information about the character of the lesion and help to choose a therapy by neuromobilisation or operative treatment. Aim: To compare results of SSS and US with intraoperative observations in a group of 24 patients operated due to peripheral neuropathy. Results: US and SSS shows a 97–100% diagnostic specificity and sensitivity These methods are also useful among patients with functional disturbances due to joint instability or presence of abnormal muscle groups like the anconeus epitrochlearis muscle, additional triceps aponeurosis or abnormality of the medial head of triceps brachii. Conclusions: Precise diagnosis helps to choose optimal therapy of UNE directed at the specific site of involvement. In our observations muscular pathology is responsible for UNE in about 40% of cases among sportsmen

Introduction: Diabetes mellitus is a systemic disease affecting peripheral nerves and the use of regional anaesthesia in diabetic patients undergoing surgery could be unpredictable. We investigated the efficacy of brachial plexus block in diabetic patients undergoing upper limb surgery compared to normal individuals. Method: Four hundred and fifty-two patients had a brachial plexus block performed under ultra-sound guidance by senior anaesthetists. There were 221 males and 231 females. Fifty-five patients were diabetic (mean age of 61 years, SD 12), 24 with type 1 and 31 with type 2 diabetes. Mean age of non-diabetic patients was 55 years (SD 15). A mixture of 0.5% Bupivacaine and 1% Prilocaine was used for the block. Post-operative proximal and distal motor and sensory functions were assessed. The assessment was conducted at a mean of 4.6 hours (SD 2.2 hours) post-operatively. MRC grading system was used to asses motor function while sensory function was assessed subjectively using a graded scale between 0, absent sensation, 1, altered sensation and 2, normal sensation. Results: Brachial plexus block was as efficient in diabetic patients proximally for motor and sensory functions compared to non-diabetic patients. There was significant difference in the efficacy of the block distally between diabetic and non-diabetic patients in both motor (P< 001) and sensory function (P< 0001). Furthermore, in diabetic patients the response to the block between type 1 and type 2 was statistically significant (P< 001). Conclusion: In diabetes, the efficacy of brachial plexus block is different compared to normal individuals. This study showed that brachial plexus block can be used efficiently in shoulder surgery in patients with diabetes. In more distal surgery, orthopaedic surgeons as well as anaesthetists should be prepared to either reinforce the block by using a local anaesthetic or to convert to general anaesthesia, if necessary, in diabetic patients

Porous collagen-glycosaminoglycan (Col/GAG) scaffolds have previously been used clinically as regeneration templates for peripheral nerves and skin. [1]. For defects involving even minimal load-bearing applications however, these scaffolds do not possess the required stiffness. Calcium phosphates (CaPs) are often used as bone-graft substitutes due to their biocompatibility and direct bone-bonding ability. While CaPs have sufficient stiffness for bone-defect applications, unlike Col/GAG they lack elasticity and are very brittle. Combining these two materials produces a composite with enhanced material properties and chemical similarity to natural bone. The addition of CaP nanocrystallites into the Col/GAG matrix produces a 3-dimensional structure that maintains its structural integrity even when wet. In this study, the in vivo performance of mineralised Col/GAG composites was evaluated by implantation into a six-week ovine bone-defect model. Four different materials were implanted; Col/GAG alone, Col/GAG with octacalcium phosphate, Col/GAG with hydroxyapatite and Col/GAG with brushite. Implants with a diameter of 9mm and length of 9mm, were placed bilaterally into the distal femoral condyle of the hind legs of thirteen sheep. This site was selected due to the large volume of load-bearing cancellous bone. Cancellous autograft was harvested from the tibial tuberosity and placed in the defect sites of two sheep as a positive control. All animals were sacrificed after 6 weeks and tissue containing the implants was prepared for histological evaluation. Image analysis of Von Kossa stained sections showed that all mineralised Col/GAG implants had significantly more bone in the implant site than unmineralised Col/GAG but were not significantly different between CaPs. Interestingly, new bone formation often followed the structure of the porous material struts which acted as a template. The defect containing the autograft contained the greatest amount of new bone. Conclusions. The inclusion of mineral substantially improves the osteoconductivity of Col/GAG. No significant difference between the different calcium phosphates was seen. Whilst these materials did not stimulate bone formation to the same extent as autograft, many bone graft procedures are carried out with allograft which performs less favourably

As they pass trough fibrous, osteofibrous and fibromuscular tunnels, peripheral nerves from their origin in the spinal cord to their effector organ, risk compression, damage and impairment of their end function. Patients present with signs and symptoms usually associated with the motor or sensory function of the involved nerve. Careful linking of these signs and symptoms can indicate a specific compressive or painful pathology commonly known as a tunnel or canalicular syndrome, and very often known as entrapment compression neuropathy. While the names may vary, according to the compressed nerve, the anatomical area affected, the motion producing the compression or the name of the describing author, these syndromes all originate from the entrapment of the nerve elements in a narrow anatomical space. Narrowing can be caused by changes intrinsic or extrinsic to the tunnel. Patients present to their physician with symptoms that can range from vague complaints of diffuse pain or numbness to specific complaints of muscle weakness or of sensory changes over localized skin areas. A careful history and physical exam must be done prior to ordering tests, scans, or electrodiagnostic studies which should be used to confirm or clarify clinical findings. MR imaging will, with an increase in resolution and a refinement in application, be of use prior to surgical exploration. Treatment of nerve entrapment syndromes, whether conservative or surgical, must address the etiology causing nerve compression. Surgical decompression (open or endoscopic) remains the resort when conservative therapy fails. In this Symposium “Nerve entrapment” the competent authors will present the general overview, MR images and electrodiagnostic of the syndromes and especially entrapment syndromes in athletes