Wood as Possible Renewable Material for Bone Implants-Literature Review.

Bone fractures and bone defects affect millions of people every year. Metal implants for bone fracture fixation and autologous bone for defect reconstruction are used extensively in treatment of these pathologies. Simultaneously, alternative, sustainable, and biocompatible materials are being researched to improve existing practice. Wood as a biomaterial for bone repair has not been considered until the last 50 years. Even nowadays there is not much research on solid wood as a biomaterial in bone implants. A few species of wood have been investigated. Different techniques of wood preparation have been proposed. Simple pre-treatments such as boiling in water or preheating of ash, birch and juniper woods have been used initially. Later researchers have tried using carbonized wood and wood derived cellulose scaffold. Manufacturing implants from carbonized wood and cellulose requires more extensive wood processing-heat above 800 °C and chemicals to extract cellulose. Carbonized wood and cellulose scaffolds can be combined with other materials, such as silicon carbide, hydroxyapatite, and bioactive glass to improve biocompatibility and mechanical durability. Throughout the publications wood implants have provided good biocompatibility and osteoconductivity thanks to wood's porous structure.

Fascial Epicondylar Augmentation in Cases of Cubital Tunnel Syndrome With Ulnar Nerve Instability.

Cubital tunnel syndrome (CubTS) is one of the most common compression-traction neuropathy in the upper extremity. The gold standard is simple in situ decompression with revision of potential compression sites through skin incision as small as rationally possible. Properly conducted conservative treatment is more effective in CubTS as opposed to carpal tunnel syndrome. At the same time, optimal management of CubTS remains controversial. Nevertheless, there is a subclass of patients with symptoms of CubTS that have ulnar nerve instability (UNI) with subluxation of the nerve over the medial epicondyle where conservative treatment would not be successful. UNI can be diagnosed by ultrasound preoperatively, but there are situations where the ulnar nerve becomes unstable with elbow flexion already on the operating table. Currently the most popular surgical reconstruction for clinically relevant UNI is anterior transposition of the nerve. With the proposed technique the nerve stays in orthotopic position, and the segmental vascularity is preserved, innervation to the flexor carpi ulnaris muscle is not jeopardized and ulnar nerve glide-floss exercises are possible as opposed to the standard subcutaneous transposition technique. No subfascial transposition, slings or blocking flaps are used for nerve stabilization which we consider contradiction to the surgery of nerve release.

Oberlin's Transfer: Long Term Outcomes.

BACKGROUND: Brachial plexus injury is very commonly associated with road traffic accidents, and frequently affects young adults, causing significant disability and impact on quality of life. The successful treatment of upper plexus injury with the Oberlin technique to restore elbow flexion with good functional results. METHODS: We retrieved the records of all patients with upper plexus injury who underwent Oberlin transfer operation between March 2007 and July 2012. Outcomes were assessed using the Medical Research Council (MRC) power grading system for biceps muscle, Disabilities of the Arm, Shoulder and Hand score (DASH) for patient functional outcomes and the Visual Analogue Scale for daily disability (VAS where 0- no restrictions; 10- significant limitations) for overall patient satisfaction. Follow-up was performed for at least 12 months post-operatively. RESULTS: The average follow up period was 43.6 months. Six cases gained effective elbow flexion, improving to MRC grade 5/5 and four cases improved to MRC grade 4/5 for biceps function. The average DASH score was 27.25. One patient had serious disability with no changes after Oberlin's transfer operation. No permanent impairment of ulnar nerve function was observed. Seven out of 10 patients had begun daily work, with no discomfort and no functional impact on activities of daily living. CONCLUSIONS: We found The Oberlin transfer is a useful salvage procedure and most effective results are for young patients with short interval between injury and operation.

Different angiogenic behaviour of ligated saphenous and epigastric vascular bundles in avascular environment: an in-vivo experimental study.

The purpose of the study was to compare angiogenic response of isolated saphenous and epigastric arteriovenous bundles in avascular environment, in an in-vivo model. Saphenous and epigastric bundles of 20 rats were dissected and ligated distally. The bundles were implanted into silicone tubing to create a biologically neutral environment. Gross and histologic examination was performed at different intervals. No thrombus was detected in any of bundles prior to 24 hours. An adherent thrombus was seen at 24 hours in all ligated saphenous bundles; it persisted at three weeks with no evidence of neovascular sprouting. The ligated epigastric bundles remained patent with evidence of neovascular sprouting. The saphenous vessels are more likely to thrombose and do not show vascular proliferation when placed in an isolated environment, whereas the epigastric vessels are likely to remain patent and show vascular proliferation.

New "loop" suture for FDP zone I injuries.

INTRODUCTION: There are many methods describing distal juncture fixation techniques of the injured flexor digitorum profundus (FDP) or flexor tendon graft. We have noted a tendency in the surgical repair of tissues toward the more expensive and technology-dependent methods. New suture type was developed to find better FDP distal juncture suture not indulging into expensive technology-dependent techniques. The positive aspect of the most popular Bunnell pullout technique is eventual removal of the suture. The negative aspect is necessity to use tie over button to secure the end of the tendon in the bone canal and thus externalizing suture. This can be complicated with maceration, decubitus, and infection. In addition, any device secured to the finger nail can be caught by external objects. MATERIALS AND METHODS: We propose buttonless method of the tendon-to-bone fixation. The only negative aspect is retaining suture. Suture is easy to perform and cheaper than any of the anchor sutures. Twelve patients were included in this preliminary study. Seven patients had acute FDP tendon zone I bone juncture injuries. Five patients had second stage flexor tendon reconstruction with tendon grafts. No infections, ruptures of the FDP or nail growth disturbances were noted. Three patients presented with slight DIP joint flexion contracture. One patient had "mallet" deformity. CONCLUSIONS: Our tendon-to-bone fixation is easy to perform. It is as cheap as standard Bunnell fixation and excludes complications encountered in standard pullout sutures. Although bone suture anchors with modified Becker core suture are superior in tensile strength to 2-stranded sutures, many hand surgeons are limited by the price of the bone anchors and can find our suture more affordable.

Evaluation of two types of vascular bundles for revascularization of avascular tissue.

PURPOSE: Implantation of vascular bundles into ischemic tissue as a means of revascularization has been performed for many decades, but there is considerable confusion regarding its clinical utility. We believe that the varying results quoted in the literature are a result of using bundles that are different from each other. We propose that vascular bundles are of 2 types: a parallel pipe type and an axial flap type. We propose that in rats, the femoral arteriovenous bundle represents a parallel pipe type and the epigastric bundle an axial flap type. We propose that if ligated and implanted into an isolated sterile environment, the parallel pipe type of vascular bundle will thrombose, whereas the axial flap type of bundle will remain patent and demonstrate neovascular sprouting. METHODS: The study was carried out in 20 rats. Femoral and epigastric bundles were dissected, ligated with 10-0 nylon, and implanted into a tubing of sterile latex. The bundles were analyzed at various time intervals by both gross and histologic examination. RESULTS: The femoral bundle did not demonstrate any arteriovenous cross-communication under magnification, confirming its status as a parallel pipe type. The epigastric bundle demonstrated a rich plexus of arteriovenous channels, confirming its status as an axial flap type. A distinct adherent thrombus was seen at 24 hours in all the ligated femoral bundles and was still present at 3 weeks; none of these demonstrated evidence of neovascular sprouting. The ligated epigastric bundles remained patent in all specimens with no evidence of thrombosis, and all demonstrated exuberant neovascular sprouting. CONCLUSIONS: Our experiment establishes that there are at least 2 distinct types of vascular bundles in the rat. It also indicates that parallel pipe type of vascular bundles implanted into latex tubing thrombose and do not demonstrate neovascularization. On the other hand, under the same circumstances axial flap bundles remain patent and demonstrate exuberant neovascularization.

Split flexor carpi ulnaris transfer: a new functioning free muscle transfer with independent dual function.

BACKGROUND: A functioning free muscle transfer is a well-established modality of restoring upper limb function in patients with significant functional deficits. Splitting the neuromuscular compartments of the free muscle based on its intramuscular neural anatomy and using each compartment for a different function would allow for restoration of two functions instead of one at the new distant site. METHODS: The authors previously reported on the clinical use of a pedicled split flexor carpi ulnaris muscle transfer. They now report the use of this muscle as a functioning free split muscle transfer to restore independent thumb and finger extension in a patient with total extensor compartment muscle loss in the forearm and a concomitant high radial nerve avulsion injury. RESULTS: Nine months postoperatively, the patient was able to extend his thumb and fingers independent of each other. CONCLUSION: This is the first report of a functioning free split muscle transfer demonstrating two independent functions in the upper limb.

Combined fractures of the body and hook of hamate: a form of ulnar axial injury of the wrist.

Fractures of the hamate are rare, and usually associated with athletes. We describe an unusual form of the injury involving fractures of the hook as well as an intra-articular medial facet. It is likely to be a result of high velocity ulnar component of the axial injury. Surgical treatment is advocated to achieve accurate reduction and apposition of the fifth carpometacarpal joint.

Salvage of an ischemic "kite" flap by arteriovenous supercharging.

The neurovascular "kite" flap is a well-established procedure for single-stage reconstruction of soft-tissue defects in the thumb. Post-surgical ischemia of the flap due to poor inflow is a rare, but potential, complication. The authors describe a technique of arteriovenous supercharging that was successfully used to salvage such an ischemic flap.