Biomedical subjects

Alexandros E Beris

Publications and source records attributed to Alexandros E Beris.

15 recordsLinked to original sources

PubMed2006

Vascularised bone grafts for the management of non-union.

Non-union of the long bones may have severe consequences, particularly when combined with other post-traumatic sequelae, such as tendon adhesions, reflex sympathetic dystrophy and infection, among others. In these cases, it is important to treat the delayed union or non-union first or at the same time with the other problems in order to achieve adequate function. Once the normal bony healing process has been slowed or stopped, it is necessary to provide both stability to the fracture site, as well as a biological stimulus for the fibrocartilagenous callus to finish the healing process. Vascularised grafts, such as the free fibula, offer not only structural support, but also promote bone healing. The later is achieved by trabecular bone formation, as well as vascular sprouting from pedicle vessels.

Bone Transplantation↗

PubMed2006

Repair of the main nerve trunk of the upper limb with end-to-side neurorrhaphy: an experimental study in rabbits.

The aim of this study was to assess the effectiveness of reinnervation using end-to-side neurorrhaphy in the upper extremity of the rabbit. The cut right ulnar nerve was repaired and sutured to the side of the median nerve about 3 cm above the elbow joint. The extent of reinnervation was quantitatively evaluated, as well as the integrity of the intact donor nerve in 36 rabbits randomly treated with fresh or delayed nerve repair with or without perineurotomy. Evaluations included nerve conduction velocity (NCV) of both the ulnar and medial nerves, dry muscle weight, and histologic examination (neurofilament stain and morphometric assessment) at 3 and 6 months postoperatively. NCV recovery rates were 79% and 87% for the ulnar nerve, and 89% and 94% for the median nerve compared to contralateral intact nerves, at 3 and 6 months, respectively. Flexor carpi ulnaris muscle mass measurements revealed a recovery in dry muscle weight of about 81% and 88% at 3 and 6 months, respectively, compared to the intact contralateral flexor carpi ulnaris. Histologic studies with neurofilament staining reveal numerous axonal sprouts at the distal end of the median nerve, indicative of myelinated axonal regeneration. Morphometric analysis demonstrated no difference between fresh and delayed repairs. These results indicate that in the upper extremity of rabbits, end-to-side neurorrhaphy permits axonal regeneration from the intact donor nerve, and is associated with satisfactory recovery. The effect of the procedure on the donor nerve was negligible.

Animals↗

PubMed2006

Long-term evaluation of rabbit peripheral nerve repair with end-to-side neurorrhaphy in rabbits.

This study was designed to quantitatively assess long-term end-to-side neurorrhaphy in rabbits. The cut right ulnar nerve was repaired and sutured to the median nerve, in which a perineurial window was created in an end-to-side fashion 3 cm above the elbow joint. Both the extent of the reinnervation and the integrity of the intact donor nerve were evaluated in 36 rabbits randomly treated with fresh or delayed nerve repair. Evaluations included motor nerve conduction velocity (MNCV), dry muscle weight (DMW), and histological examinations at 9 and 12 months postoperatively. The recovery rates of MNCV were 90.1% and 92.8% for the ulnar nerve, and 95.7% and 96.8% for the median nerve, compared to intact contralateral nerves at 9 and 12 months, respectively. MNCV was not detectable for the ulnar nerve in control animals, while it was normal for the median nerve. Recoveries of flexor carpi ulnaris dry muscle weight of about 90.7% and 94.5% were observed at 9 and 12 months postoperatively, respectively. However, muscle mass measurements revealed a recovery of only 31.3% and 27% for control groups at 9 and 12 months postoperatively. The differences between experimental groups and control groups were statistically significant (P < 0.01). Neurofilament and silver stains showed numerous sprouting axons originating from the median nerve to the ulnar nerve. The results indicate that end-to-side neurorrhaphy could induce axonal sprouting from the main nerve trunk of upper limbs in rabbits, leading to useful functional recovery.

Animals↗

PubMed2006

Sciatic and peroneal nerve injuries.

In the past, the attitude toward surgical repair of sciatic and peroneal nerve lesions was excessively pessimistic. Refinements of microsurgical technique, nerve conduction studies, and the establishment of indications and optimal timings for surgical interventions have led to significant improvements in outcomes, making repair worthwhile in most cases. Tendon transfers can augment functional outcomes, and are performed as secondary procedures or (in selected cases) in combination with the initial repair. Developments in the basic sciences, bioengineering, and medical imaging may further improve the results of management of these serious nerve injuries.

Algorithms↗

PubMed2006

Musculocutaneous neurotization to restore elbow flexion in brachial plexus paralysis.

Brachial plexus injuries may result in devastating paralysis, especially if they involve all the roots. The upper roots are often traumatized, and therefore elbow flexion is usually lost. The prognosis of these injuries is grave if root avulsions are present and the paralysis includes the hand as well. The current management of brachial plexus injuries should be early, aggressive microsurgical reconstruction of the plexus, combining various neurotizations with intraplexus and extraplexus nerve donors. Following this principle, we present the results of musculocutaneous neurotization in our unit, as well as a review of the literature on this subject. Our results are comparable to those reported in the literature, and indicate that the strongest function is achieved after neurotization via intraplexus donors, while some extraplexus donors (i.e., phrenic and accessory nerve) can offer equally strong elbow flexion, especially if they are used in combination. Neurotization of the musculocutaneous nerve should be one of the primary goals in the reconstruction of the injured plexus, since the return of elbow flexion is of paramount importance in daily activity. The restoration of function is ensured if the stronger and healthier motor donors are dedicated to the neurotization of the musculocutaneous nerve. Sometimes in order to match the axonal number of the target to the lower number of axons offered by the donors, two or more donor nerves may be driven to the same target, such as the musculocutaneous nerve.

Adult↗

PubMed2006

Microsurgical dissection of the carpal tunnel with respect to neurovascular structures at risk during endoscopic carpal tunnel release.

PURPOSE: The goal of this descriptive study was to investigate the anatomy of the carpal tunnel with respect to the related neurovascular structures, because a detailed knowledge of the complex anatomy of this region is essential to perform endoscopic carpal tunnel release. METHODS: Sixteen fresh-frozen cadaveric hands were used for the study. Dissection of the palmar aspect of the hand was performed by use of magnifying loupes, an operative microscope, and microsurgical instruments. All anatomic components were photographed, and dimensions were recorded by use of a micrometer. The distance from the radial aspect of the os pisiformis and the proximal and distal portals to the main structures that may be injured was measured. Topography of the transverse ligament and possible adhesions to the tendons and median nerve were also recorded. RESULTS: The mean distance from the radial aspect of the os pisiformis to the radial border of Guyon's canal and the ulnar edge of the palmaris longus tendon was 10.3 mm (range, 9 to 12 mm) and 16.1 mm (range, 12 to 22 mm), respectively. The mean distance from the distal portal to the superficial palmar arch and the ulnar artery was 10.4 mm (range, 5 to 15 mm) and 7.6 mm (range, 4.5 to 9 mm), respectively. The mean distance from the distal edge of the transverse ligament to the thenar branch of the median nerve was 2.7 mm (range, 0 to 4.1 mm). The mean length of the transverse ligament was 31 mm (range, 25 to 34.5 mm). In 14 hands we also identified the palmaris longus tendon. In 11 hands we found adhesions between the transverse ligament and the sheath of the flexor tendons. CONCLUSIONS: The palmaris longus can be used as a guide for the placement of the proximal portal. Staying at the ulnar side of the palmaris longus keeps the superficial palmar branch of the median nerve at a safe distance from the instruments. The "fat drop sign" is also a useful guide for the placement of the distal margin of the transverse carpal ligament, keeping the distal portal away from the superficial palmar arch. Synovial adhesions can usually cover the inferior surface of the transverse ligament, and they need to be removed for clear endoscopic identification of the transverse fibers before the ligament is cut. CLINICAL RELEVANCE: Detailed knowledge of the complex anatomy of the carpal tunnel is essential to perform endoscopic carpal tunnel release.

Aged↗

PubMed2006

Current concepts in delayed bone union and non-union.

Healing of a fracture is a continuous process that involves various types of histologic regeneration at different sites. This article describes current approaches to managing delayed union and non-union of fracture.

External Fixators↗

PubMed2006

Pediatric fractures of the foot and ankle.

Distal tibial physeal injuries are common in children, accounting for 10% to 40% of all injuries to skeletally immature patients. This article describes the classification, treatment, and complications of distal tibial fractures, fractures of the talus and calcaneus, midfoot and tarsometatarsal injuries, metatarsal fractures, and fractures of the phalanges in children.

Calcaneus↗

PubMed2005

Decompressive surgery for degenerative lumbar spinal stenosis: long-term results.

We report the outcome of 50 patients with degenerative lumbar spinal stenosis who were treated surgically by spinal decompression between 1984 and 1995. Their mean age at the time of surgery was 59.9 (45-77) years and the mean follow-up was 11.6 (6.1-17.2) years. Five patients had a concomitant spinal fusion. The preoperative data were collected retrospectively from the patients' charts. The follow-up data were obtained from a clinical examination and questionnaire including overall pain, ability to work, walking ability, use of analgesics and satisfaction with surgery. The outcome was rated as excellent in 23 patients, good in 13 patients, fair in 9 patients and poor in 5 patients. Patients with concomitant fusion had good to excellent results and were more satisfied, whereas patients with long-standing preoperative symptoms had poor to fair result and were less satisfied.

Aged↗

PubMed2005

Advances in articular cartilage repair.

Many joint and systemic disorders may lead to cartilage defects. Partial thickness defects of the articular cartilage do not have healing potential. When the lesion reaches the subchondral bone, spontaneous healing may be observed, but consists of fibrocartilaginous tissue. The main efforts for cartilage repair are targeted at filling of the cartilage defect with a tissue that possesses the same mechanical properties with hyaline cartilage and the consolidation of this tissue with the native articular cartilage. There are various arthroscopic techniques and although they provide pain relief, they do not restore the damaged cartilage. Osteochondral transplantation is more effective in dealing with small or medium size full thickness defects, but further efforts are required in order to reduce the donor site morbidity, marginal necrosis and partial covering of the defect.

Arthroscopy↗

PubMed2004

Non-union of femoral neck fractures with osteonecrosis of the femoral head: treatment with combined free vascularized fibular grafting and subtrochanteric valgus osteotomy.

Femoral neck fractures, frequently complicated by non-union and femoral head osteonecrosis,present a difficult clinical situation, especially when young patients are concerned. Existing treatment options are valgus osteotomy to address the biomechanical factors or bone grafting to address the biologic factor. The authors describe the operative technique and results of combined subtrochanteric valgus osteotomy and free vascularized fibular grafting in management of five young patients with both non-union and avascular necrosis.

Adolescent↗

PubMed2004

Diagnosis and management of the osteonecrotic triad of the knee.

Generalized osteonecrosis of the knee may include, in addition to osteonecrosis of the medial femoral condyle that occurs most frequently, osteonecrosis of the patella or the tibial plateau. Such involvement is known as the osteonecrotic triad of the knee. Although the clinical picture of idiopathic osteonecrosis of the medial femoral condyle seems similar to several other disorders, certain distinct features, including its typical location,clinical symptoms, and late onset of cartilaginous erosion, facilitate differential diagnosis. Despite the progress made in the diagnosis and treatment of idiopathic osteonecrosis of the medial femoral condyle, the prognosis remains severe. More than 80% of the patients deteriorate to the extent that surgical reconstruction is necessary, whereas only about 20%of the patients demonstrate spontaneous resolution or no additional deterioration of the osteonecrotic lesion.

Adult↗

PubMed2003

Two-stage flexor tendon reconstruction in zone II using a silicone rod and a pedicled intrasynovial graft.

PURPOSE: To evaluate the results of a modified Paneva-Holevich technique for flexor tendon reconstruction in zone II. METHODS: Twenty patients (22 digits) with poor prognosis injuries (Boyes grade 2-5) were reconstructed. The technique included placing a silicone rod and creating a loop between the flexor digitorum profundus (FDP) and the flexor digitorum superficialis (FDS) in the first stage and reflecting the latter as a pedicled graft through the pseudosheath created around the silicone rod in the second stage. RESULTS: After a follow-up period of at least 1 year (mean, 50 mo) the rate of good and excellent results was 82% according to the Buck-Gramco scale and 73% using the modified Strickland scale. CONCLUSIONS: These results compare favorably with those using the classic (Hunter) 2-stage reconstructions with a silicone rod and a free tendon graft. Apart from technical versatility, additional advantages of the technique include using a local intrasynovial graft, the absence of donor site morbidity, and a low rate of postreconstruction tendon ruptures and tenolysis.

Adolescent↗

PubMedDate not supplied

Two-stage flexor tendon reconstruction in zone 2 of the hand in children.

Two-stage flexor tendon reconstruction (Hunter) is indicated in children with extensive adhesions in zone 2 of the hand, with some reservations concerning the patient's age and cooperation. Nine children (mean age 6.9 years) were treated with the modified Paneva-Holevich technique, which has advantages over the classic Hunter reconstructions. It involves an intrasynovial graft (FDS of the injured finger) that is anatomically stable and morphologically more appropriate compared with free grafts. The size of the silicone rod is precisely assessed in the first stage, the proximal tenorrhaphy has healed by the time the second stage is performed, and donor site morbidity is minimized. After a mean follow-up of 40.1 months, the mean total active motion was 196 degrees, and eight patients achieved a good or excellent result according to the Buck-Gramcko and the revised Strickland scale. Staged flexor tendon reconstruction is technically feasible even in very young children. Results in children are comparable to those achieved in adults.

Adolescent↗

PubMedDate not supplied

Free vascularized fibular grafts for reconstruction of skeletal defects.

Nourished by the peroneal vessels, the versatile free vascularized fibular graft can be transferred to reconstruct skeletal defects of the extremities. It may be combined with skin, fascia, muscle, and growth-plate tissue to address the needs of the recipient site. It may be cut transversely and folded to reconstruct the length and width of tibial or femoral defects. The main indications for this graft are defects larger than 5 to 6 cm or with poor vascularity of the surrounding soft tissues. Detailed preoperative planning, experience in microvascular techniques, and careful postoperative follow-up are necessary to minimize complications and improve outcome. The free vascularized fibular graft has been successfully applied as a reconstruction option in patients with traumatic or septic skeletal defect, after tumor resection, and has shown promise in patients with congenital pseudarthrosis.

Bone Neoplasms↗