An Experimental Model on the Biomechanical Behaviour of the Flexor Tendons in New Zealand Rabbits.

BACKGROUND: In order to introduce new pharmacological agents with the intent to inhibit the adhesion formation, it is important to test such products on laboratory animals under a protocol that can evaluate the quantitative and qualitative aspects of healing of the tendons. Most experimental models focus on the tensile strength and histological analysis of the tendons, failing to sufficiently quantify the degree of the adhesion formation. METHODS: The experiment included six male New Zealand rabbits that underwent surgery of their right forepaws. The deep flexor tendon of the middle finger was transected and repaired and after six weeks the rabbits were killed. In order to assess the extent of adhesions, the functional stiffness of the tendons and the range of motion of the specimens' fingers was studied using a tensile testing machine. The setup used allowed the simultaneous recording of the specimens' motion and the pulling force values. RESULTS: The mean values of the left and right forepaws were expressed in the same chart showing a clear difference between the operated and non operated forepaws. CONCLUSIONS: Using a relatively simple set up in the laboratory we had the chance to focus on a more elaborate analysis of the data with the help of low cost and accessible software.

Differences of bone mineral mass, volumetric bone mineral density, geometrical and structural parameters and derived strength of the tibia between premenopausal and postmenopausal women of different age groups: a peripheral Quantitative Computed Tomography (pQCT) study.

Menopause constitutes a significant cause of bone loss, and it is currently debated whether bone mass is preserved or begins to decline substantially before that time in women. We used pQCT of the tibia to estimate differences of bone mineral mass, bone geometry and derived strength between premenopausal and postmenopausal Caucasian women of different age-groups per decade of age (20-79y). For each individual, we assessed total, trabecular and cortical bone mineral content (BMC, mg) and volumetric bone mineral density (BMD, mg/cm3); total and cortical cross-sectional areas (CSA, mm2); periosteal circumference (PERI_C, mm); endosteal circumference (ENDO_C, mm); mean cortical thickness (CRT_THK, mm); and Stress-Strain Index (SSI) . Comparisons were made both between premenopausal (N=84) and postmenopausal (N=231) women as distinct groups, and among women of the different age-groups. Our results indicated that premenopausal women had significantly higher trabecular and cortical BMC and vBMD, with higher cortical CSA, CRT_THK and SSI than postmenopausal women. Moreover, significant differences of trabecular but not cortical BMC, vBMD or SSI were found between women of the younger (<48y) age-groups. PERI_C, ENDO_C displayed lower values in the 20-29y group and higher values in the 70-79y group, denoting significant differences of bone geometry with aging.

The role of Taylor Spatial Frame for the treatment of acquired and congenital tibial deformities in children.

This study evaluates the use of the Taylor Spatial Frame (TSF) for the correction of acquired and congenital tibial deformities in children. The purpose is to underline problems, obstacles and complications that can be observed during treatment to reveal the learning curve and potential risk factors and to propose solutions to avoid difficulties during its use 86 tibia deformities were corrected in 66 children during a period of 7 years and were classified according to anatomical and dominant type of deformity. Follow up was 54.2 months. Gradual correction was performed according to the individualized time schedule. We faced 42 difficulties: 29 problems, 10 obstacles and 3 complications, distributed across all years. Significant correlation was found between patient's age and number of difficulties. The incidence of the difficulties was equally spread over the different etiologies, but it was statistically significant across the years. Proximal tibia and complex multi-plane deformities seem to be related to an increased incidence of postoperative difficulties. TSF can yield accurate results, is easy to handle and provides an excellent concomitant 3-direction correction.

Anatomical study and colour Doppler assessment of the skin perforators of the anterior tibial artery and possible clinical applications.

BACKGROUND: Traumatic or trophic defects of the soft tissue of the lower leg are quite often very difficult to manage, especially in the distal third of the leg. Fasciocutaneous flaps are a relatively simple option for covering small- and medium-sized defects of the lower leg. The aim of this study is to investigate the distribution of septocutaneous perforators of the anterior tibial artery and their possible clinical applications. METHODS: An anatomical study was performed on 50 fresh adult cadaveric lower extremities. Using coloured contrast materials, the location of septocutaneous perforators, originating from the anterior tibial artery, were mapped. These findings were then compared with colour Doppler imaging (CDI) data in 20 living volunteers. RESULTS: The septocutaneous perforators of the anterior tibial artery follow a reproducible pattern all over the lower leg (septa I, II and III). In the distal segment, we found relatively few perforators. There was a marginal difference between cadaveric and CDI data for perforators with diameter >or=1mm. The average number of anterior tibial artery septocutaneous perforators in anatomical dissections was 6.6+/-2.4, while CDI revealed 8.2+/-3.2 perforators in living volunteers (P=0.053). In five areas of the lower leg, there is a >50% chance that a septocutaneous perforator with diameter >or=1mm is coming off the anterior tibial artery. Anatomical dissections for a cutaneous territory 5 cm above the lateral maleollus, and 10 cm in width, revealed 6.1+/-2.2 septocutaneous perforators (range 4 to 12). CONCLUSIONS: CDI, paired with knowledge of anatomical details, is a reliable tool for preoperative identification of septocutaneous perforators of 1mm or larger outer diameter, thus providing critical information for planning and harvesting safe fasciocutaneous flaps of the lower leg. Additionally, according to our anatomical study, a new transverse fasciocutaneous flap (Type B according to the Nahai-Mathes classification), located over the distal anterolateral third of the lower leg and based on perforators of the anterior tibial artery, may be successfully used for covering selected defects of the distal third of the lower leg.

Degenerative spondyloarthropathy of the cervical and lumbar spine in jockeys.

This prospective study analyzed the long-term effects of horse riding on the cervical and lumbar spine of jockeys. Thirty-two jockeys were observed for 13 years. All jockeys had clinical and radiographic evaluation of the spine; three consecutive age groups were studied. Results were compared to age-matched, normal population control groups. The incidence of degenerative changes of the spine was higher in the jockeys compared with the control groups and was more prominent in the older age group for both the lumbar and cervical spine. These findings suggest that equestrian sports, particularly professional horse riding, apart from the increased risk of direct spinal injury caused by a fall from the horse, can lead to progressive spine degeneration as a result of repetitive trauma and increased physical stress on the spine.

Fixation of femoral shaft fractures with a flexible bundle-type nail.

In a prospective study, 31 consecutive patients with a femoral shaft fracture were treated with the Marchetti-Vicenzi intramedullary flexible bundle-type nail. Open reduction of the fracture was necessary in 25 of the 31 patients (81%). Twenty-five of the 31 fractures (81%) united within 2.5 to 6 months after the operation (mean, 4.2 months). Nonunion occurred in one patient (3.2%). Other complications included delayed union in five patients (16%), femoral shortening in five (16%), breakage of the distal pins in two (6.5%), and severe varus malunion in two patients (6.5%). Because of the high complication rate in this series, the authors no longer use the Marchetti-Vicenzi flexible nail for treatment of femoral shaft fractures.

Operative treatment for Maisonneuve fracture of the proximal fibula.

This study reviewed operative treatment of Maisonneuve fracture of the fibula in 26 patients. Operative treatment consisted of restoration of the fibular length, repair of the lateral and medial ankle ligamentous structures, and placement of one or two suprasyndesmotic screws. After average follow-up of 6.4 years, the clinical results were satisfactory in 23 (88.4%) patients. Operative treatment is the treatment of choice for Maisonneuve fractures, and a satisfactory outcome may be anticipated after appropriate management of any associated bony and syndesmotic injuries.

The significance of rotation in fracture-separation of the articular pillar of a lower cervical vertebra. A clinical and cadaveric study.

We report 13 fracture-separations of an articular pillar at the lower cervical spine in 12 patients. There were 9 men and 3 women with a mean age at injury of 32 years, with involvement of C4, C5 and C6 vertebrae. Neurological symptoms were present in 9 patients, 2 were classified as ASIA A and 7 as ASIA D. The average magnitude of rotation of the articular pillar was 24 degrees (10 degrees-36 degrees). 4 patients with neurologic deficit and a rotated articular pillar of more than 25 degrees were operated on, while 8 patients, 3 of which had a rotation of more than 25 degrees, had closed treatment. Patients were followed from 8 months to 15 years (mean 9 years). Patients who had closed treatment and/or with a rotated fractured articular pillar of more than 25 degrees had less satisfactory results. This observation was affirmed by cadaveric studies which showed that rotation of more than 25 degrees is an additional factor of instability in a fractured articular pillar.

Surgical treatment of 35 volar Barton fractures. No need for routine decompression of the median nerve.

35 patients with volar Barton fractures were treated operatively from 1985-1994. The injury was due to a high velocity motor vehicle accident in 20 patients. All fractures were closed without major carpal injuries. 11 fractures were type B3.1, 21 type B3.2 and 3 type B3.3. according to the AO classification. All fractures were openly reduced and internally fixated by small buttress plates and screws. In 31 cases, the median nerve was unaffected by the injury and was not explored or decompressed during surgery. The patients were assessed clinically and radiographically after mean 6 (2-10) years. According to the criteria of Pattee and Thompson (1988), 23 patients had excellent results, 10 good and 2 fair. Posttraumatic arthrosis was found in 12 patients and was related to the congruency of the articular surface achieved at surgery. We conclude that the median nerve, when not damaged or compressed, should not be explored or decompressed during surgery.

Two-level dorsal dislocation of the little finger.

The case of an elderly man who suffered simultaneous interphalangeal joint dislocation in one finger as a result of a hyperextension force on both the distal and proximal interphalangeal joints is presented. This case differs from the few reports of this type of injury in the literature both in its mechanism of injury and time to reduction. Most reports have been in athletes who are actively involved in a sport, whereas the present case was the result of a fall. Also, successful reduction was achieved almost 2 weeks postinjury, indicating that, even with this amount of delay, these injuries can be effectively treated with closed reduction.

Alternative techniques for restoration of bony segments in digital replantation.

We present our experience from 108 partially or totally amputated digits in 87 patients which were replanted or revascularized successfully by the Orthopaedic Microsurgical Team at the University of Ioannina Medical School in Greece, during the period from 1978 to 1994. The majority of the patients were men involved in occupational accidents. Bone shortening always preceded the osteosynthesis and the vessel anastomosis, and most of the available methods for osteosynthesis were used, including small plates, single lag screws, crossed Kirschner wires, a combination of intraosseus cerclage wires and Kirschner wires, and intramedullary Kirschner wires. Our findings suggest that the most appropriate method for bone fixation in digital replantation is the insertion of one intramedullary Kirschner wire, supplemented by another wire which is inserted at the end of the procedure. This technique was found superior for the following reasons: 1) it's simplicity and the speed of the technique reduced the ischemic time; (2) less bone exposure was required; (3) less skeletal mass was needed for fixation; and (4) prior to the insertion of the second Kirschner wire, rotation of the replanted part was possible if it was necessary to re-align the vessels or to correct any rotational deformity.

The effect of heparin after microsurgical repair in traumatically damaged arteries.

A main consideration of microvascular surgery is the avoidance of thrombosis. This traditionally involves the avoidance of thrombogenic trauma, the establishment of normal blood flow and full vessel diameter, as well as the use of anticoagulants, such as heparin, as an antithrombotic measure. In the present study we assessed the effectiveness of heparin in maintaining patency in the femoral arteries of rats which have undergone a crush injury with damage to the intima and media layers of the wall. To accomplish this, the animals were treated with heparin 150 units or 300 units twice daily following microvascular repair using standard microsurgical techniques. Control animals received no treatment. The results of this study indicate that the number of patencies in experimentally-injured femoral arteries did not improve significantly following heparin treatment, although pharmacological doses of heparin (300 units twice daily) were associated with a somewhat lower rate of occlusions. We conclude that heparin appears unable to significantly prevent clotting in vessels which have experienced severe trauma to the intima and media layers.

The "tear drop" (or avulsed) fracture of the anterior inferior angle of the axis.

Fourteen cases of an anterior inferior angle fracture of the axis treated in the Orthopaedic Department of the University of Athens from January 1970 to December 1992 were analysed. The mean follow-up time was 8.5 years. The so-called "tear drop" fracture of the axis composes a special entity characterised by an avulsed fragment, of varying size, from the anterior inferior angle of the body of the axis as a result of hyperextension. This type of injury is not a frequent one, representing 3% of the cervical spine trauma in our Department. There were eight men and six women with a mean age of 47 years. Road traffic accident is by far the most common mode of aetiology. The stability of this lesion is questioned by certain authors, resulting in disagreement concerning the choice of treatment to be followed. All the patients in our series were treated conservatively, consisting at the beginning with Glisson traction and then the use of a simple cervical collar. The rotation of the detached fragment, its anterior displacement, the posterior displacement of the vertebral body as well as the presence of instability at the C1-3 levels were analysed. The high incidence of co-existing lesions at the same or at a more distal level is discussed. This study revealed that there was no significant displacement of the vertebral body, and thus disturbance of the posterior ligaments, rendering the fracture stable.(ABSTRACT TRUNCATED AT 250 WORDS)

Hemodynamic and histological differences in end-to-side anastomoses.

An end-to-side anastomosis is often a necessity in replantation surgery. This study examines the effects of elliptical versus slit arteriotomy and the angle of anastomosis on vessel patency and aneurysm formation. Forty male rats were divided into four groups of ten rats each. The right and left common iliac arteries were selected as a model. The results showed no significant statistical difference in patency rates among our four experimental groups. The end-to-side anastomotic technique of choice uses the elliptical arteriotomy placed at a 90 degrees angle. It provides good visualization and easy suture placement.