Acute impact of blood flow restriction on strength-endurance performance during the bench press exercise.

The main goal of the present study was to evaluate the acute effects of blood flow restriction (BFR) at 70% of full arterial occlusion pressure on strength-endurance performance during the bench press exercise. The study included 14 strength-trained male subjects (age = 25.6 ± 4.1 years; body mass = 81.7 ± 10.8 kg; bench press 1 repetition maximum (1RM) = 130.0 ± 22.1 kg), experienced in resistance training (3.9 ± 2.4 years). During the experimental sessions in a randomized crossover design, the subjects performed three sets of the bench press at 80% 1RM performed to failure with two different conditions: without BFR (CON); and with BFR (BFR). Friedman's test showed significant differences between BFR and CON conditions for the number of repetitions performed (p < 0.001); for peak bar velocity (p < 0.001) and for mean bar velocity (p < 0.001). The pairwise comparisons showed a significant decrease for peak bar velocity and mean bar velocity in individual Set 1 for BFR when compared to CON conditions (p = 0.01 for both). The two-way repeated measures ANOVA showed a significant main effect for the time under tension (p = 0.02). A post-hoc comparisons for the main effect showed a significant increase in time under tension for BFR when compared to CON (p = 0.02). The results of the presented study indicate that BFR used during strength-endurance exercise generally does not decrease the level of endurance performance, while it causes a drop in bar velocity.

Can Supplementation of Vitamin D Improve Aerobic Capacity in Well Trained Youth Soccer Players?

There is no clear evidence that vitamin D effectively improves physical capacity in high-level athletes. The aim of this study was to confirm that vitamin D supplementation of soccer players during eight-week high-intensity training would have a significant effect on their aerobic capacity. The subjects were divided into two groups: the experimental one that was supplemented with vitamin D (SG, n = 20), and the placebo group (PG, n = 16), not supplemented with vitamin D. All the players were subjected to the same soccer training described as High-Intensity Interval Training (HIIT). The data of the vitamin D level, PWC170, lactate threshold (LT) were collected just before and after the intervention. A significant increase in vitamin D concentration (119%) was observed in the supplemented group, while the non-supplemented group showed a decrease of 8.4%. The studied subjects improved VO2max results by 20% in the SG, and by 13% in the PG. The improvement in velocity at the LT was similar in both groups. Results of this study show that vitamin D can have a positive, though moderate, effect on aerobic performance in players subjected to high-intensity training in the form of small-sided games for 8 weeks.

[Results of operative treatment thoraco-lumbar fractures by posterior lumbar interbody fusion, Daniaux reconstruction or combination of both methods]. / Wyniki operacyjnego leczenia zlaman kregoslupa piersiowego i ledzwiowego tylna spondylodeza miedzytrzonowa, rekonstrukcja trzonu wedlug Daniaux oraz obiema metodami równoczesnie.

The aim of the study was to compare clinical and radiological results of treatment thoraco-lumbar spine fractures by short segment transpedicular stabilization accompanied by three techniques of reconstruction: posterior lumbar interbody fusion, vertebral body Daniaux reconstruction and combination of both methods. AO system was used to classify the fractures. Frankel's grade system was used for assessment of neurological deficit on admission and subsequently in the postoperative and follow-up period. The height of the fractured vertebral body and angle of segmental kyphotic deformation was measured on lateral X-ray pre- and post-operatively and at last follow-up. To the retrospective analysis we included 167 patients operated in the Orthopaedic and Traumatology Department, Medical University of Lublin in years 1998-2007. Posterior lumbar interbody fusion was performed in 69 patients (41%), isolated vertebral body Daniaux reconstruction in 82 patients (49%) and combination of both methods was performed in 16 patients (10%). The follow-up period has ranged from 3 to 13 years (mean 6.9 years). The most common type of the fracture was a B type (104 patients -62%), followed by type A (43 patients--26%), and type C (20--patients 12%). The neurological deficit was present in 80 patients. The postoperative neurological improvement was noticed in 37 patients (46%), whereas in 46 patients (54%) neurological status has not changed after the treatment. From 87 patients without neurological symptoms, we observed postoperatively contemporary neurological complications in 11 (12.6%) cases. The biggest correction of fractured vertebral height (mean 0.15) and correction of segmental kyphotic deformity (mean 6.3 degrees) we have noticed in the group of isolated vertebralbody Daniaux reconstruction with use of bone grafts. However in every group of patients we observed significant loss of correction during follow-up period. At the latest follow-up assessment there were no differences in vertebral body height of segmental kyphotic deformation between the analyzed groups of patients. None of analyzed methods of treatment: posterior lumbar interbody fusion, vertebral body Daniaux reconstruction or combination of these methods did not protect from recurrence of kyphotic deformity.

Covalent coating of hydroxyapatite by keratin stabilizes gentamicin release.

A novel hybrid hydroxyapatite (HAP) matrix, covalently coated with rarely applied, hardly degradable keratin and effectively modified by gentamicin immobilized in mixed-type mode (via interactions of diverse strength), was created. This hybrid showed a remarkably high drug immobilization yield and the most sustainable antibiotic release among all tested composites. It was also able to inhibit bacterial growth, both in surrounding liquid and on matrix surface, much longer (for at least 121 days of experiment) than analogous gelatin-modified and nonmodified matrices. Gentamicin-keratin-coated-HAP granules were nontoxic to human osteoblasts and enabled their proliferation with a rate similar as noncoated HAP. Presence of keratin on HAP granules seemed to slightly enhance the osteoblast proliferation. The results indicate that newly created HAP hybrid with covalently immobilized keratin and gentamicin--nontoxic and osteoblast-friendly--is a promising biomaterial of significantly prolonged antibacterial activity.

Treatment outcome after one-stage reconstruction of the anterior cruciate ligament and mosaicplasty of the articular cartilage of the knee.

Background. Chronic rotational instability of the knee after damage to the anterior cruciate ligament (ACL) fairly quickly produces undesirable secondary changes in the joint. Concomitant damage may affect the meniscus or the articular cartilage of the femoral condyle. The purpose of our study was to compare outcome in patients who had undergone one-stage surgical repair of damage to the ACL and articular cartilage. Material and methods. We studied 17 patients with associated cartilage and ligament damage. The control group consisted of 36 patients with isolated ACL damage. Joint function was assessed according to the Marshall Scale and the Lysholm and Gilquist Scale. Examinations were performed before treatment, 2 and 6 weeks post-operatively, and again 3, 6 and 12 months after surgery. Results. In the course of rehabilitation we observed a slightly slower recovery in the patients with combined damage up to 6 months after surgery. There were no statistically significant differences in rehabilitation outcome at the end of the observation period Conclusions. This treatment method has the potential to permanently remedy knee slippage and cancel its early effects. The surgical outcome in repair of damage to the patellofemoral joint, combined with centralization of the knee's extension apparatus, are comparable at 2 years to centralization of the patella alone when the normal structure of the articular cartilage has been perserved.

[Transpedicular reconstruction of vertebral body height with simultaneous interbody spondylodesis]. / Transpedikularna rekonstrukcja wysokosci zlamanych trzonów kregowych z równoczesna spondylodeza miedzytrzonowa

BACKGROUND AND PURPOSE: Surgical treatment of traumatic spinal injury should include fast and complete decompression of spinal cord and radices wits reduction of broken vertebral body, restoration of physiological spinal curvatures and spondylodesis of injured segments. Restoration of natural spinal curvatures is only possible when the height of broken vertebral body is reconstructed. MATERIAL AND METHODS: Between 1992 and 2001, 75 patients were operated on because of traumatic injuries of thoracolumbar spine in the Ortopaedic and Traumatology Department Skubiszewski Medical University of Lublin. 48 patients had broken vertebral body reduction with simultaneous filling of bone loss with autogenic bone grafts inserted through pediculum. Only in 4 cases posterior spondylodesis was carried out on arches and spinous processes. Transpedicular plasty of 44 broken vertebral bodies was connected with posterior interbody fusion with PLIF technique using graft application to interbody space. RESULTS: The operative protocol presented above allowed for the height of the anterior vertebral wall to be restored on average to 81.5% of the original height. We did not observe either fatigue breakage of the screws or screws loosening with kyphosis recurrence. We did not note serious postoperative complications, including neurological compromise. The operative procedure did not significantly change the neurological status of the patients. In 9 cases we noted neurological improvement: usually by 1 or 2 grades in Frankel's score. CONCLUSIONS: Restoration of the fractured vertebral body with bone grafts combined with posterior interbody spondylodesis effectively prevents the recurrence of the kyphotic deformation.

Posterior interbody fusion in the treatment of diseases and injuries of the thoraco-lumbar spine.

Background. The aim of our study was to evaluate the effectiveness of posterior interbody spondylodesis with autogenous bone grafts in the treatment of diseases and injuries of the thoraco-lumbar spine. Material and methods. In the period 1994-2003 122 patients were treated in the Orthopedics and Traumatology Department of the Skubiszewski Medical University of Lublin with posterior interbody fusion. The indications for surgery were spondylolisthesis in 24 patients, and injuries to the thoraco-lumbar spine in 98 patients. Results. Intraoperative injury of the spinal dura occurred in 4 patients. Graft migration to the vertebral canal with radicular pain occurred in one patient 4 weeks after surgery. Bone graft incorporation was observed in all patients. There was no breakage of instrumentation or loss of spondylolisthesis reduction. Conclusions. Posterior interbody fusion is an effective method of treatment to achieve durable stability of injured segments of the thoraco-lumbar spine.

Metacarpal fractures.

Background. The purpose of our study was to evaluate bone union in metacarpal fractures, in terms of the pathomorphic nature of the damage and the use of surgical treatment. Severe multi-tissue damage and fracture with Bennett's dislocation were excluded. Material and methods. At the Clinic of Orthopedics and Traumatology in Lublin, 92 patients were hospitalized from 1991 to 2001 for metacarpal fractures. Most of the fractures had an oblique or spiral course. In 18 patients with associated multi-organ injuries and multiple fractures, non-surgical treatment with plaster casts was applied. In 39 patients surgical treatment was applied. The metacarpal fractures were stabilized with crossed or intramedullary Kirschner wires, microscrews, or plates and screws. Results. In 32 cases we obtained bone union and complete pain-free hand function. Complications occurred in 7 cases: loosening of the union, severance of the extensor tendons, tenodesis of the extensor tendons, and slow bone union. Conclusions. Stabilization of bone fragments with Kirschner wires, a generally available and easy method, can be used in most types of metacarpal fracture.

Complications of transpedicular spine fixation and their causes.

Background. Transpedicular stabilization of the spine caries the risk of complications. Iatrogenic neurological symptoms after spinal cord or spinal roots involvement, misguided screws, stress fractures and loosening of screws are the most dangerous.
The aim of the study was the assessment of reasons and types of complications after transpedicular stabilization.
Material and methods. We assessed 138 patients treated in Orthopaedic Department, Medical Academy of Lublin in years 1993-2001. Operative indications in 73 cases were trauma and in 41 cases were spondylolisthesis and tumors.
Results and Conclusions. 2 patients (1,45%) died in early postoperative period due to gastric ulcer perforation and thoracic trauma. In 1 patient (0,73%) septic complications occurred. Incorrect introduction of transpedicular screws was found in 4 patients (2,95%) -i 2 patients they perforated lateral wall of the vertebral body and in 2 patients internal wall of the spinal canal. Stress fractures of the screws were found in 3 patients (2,17%) after one year from the operation. In all four cases the reason of the fracture was lack of spondylodesis. In 5 patients (3,68%) we noticed dura mater lacerations caused by intraoperative separation of fractured vertebral body or tumor.

Investigations of ultrastructure of damaged and regenerated skeletal muscle fibers.

Our investigations concerned the head of the parietal part of quadriceps femoris, and we based our investigation on observations of the ultrastructure of muscle fibers using an electron microscope. We observed tissue samples taken from patients (10 men) 25-35 years old, who had old damage of knee joint ligament (after about 6 week's immobilization). In the first group, segments of tissue of parietal head of quadriceps femoris were taken inter-operationally from patients in whom there was found old damage of knee joint ligament. The second group was of tissue segments of this muscle after surgical repair of knee and rehabilitation, which consisted in power training using resistance machines. The muscle fiber samples of quadriceps femoris which were taken from patients during the first operation, showed big changes in their ultrastructure. These changes included: myofibrils disintegration; disturbance of regularly arranged striation in sarcomers; dissappearance of Z line. In the sarcoplasm, we observed large vacuolisation, and in the interfibrillar spaces--an accumulation of exudate and morphotic elements of blood outside the capillary vessels. Observations of muscle tissue after regeneration, showed a big improvement in the muscle cell's ultrastructure--the myofibrils were regularly arranged, and the sarcomers striations showed no deviations from normal structure. We also observed a considerable increase in the number of properly formed ultrastructure mitochondria when compared with the first group.

[One-stage approach to the anterior and posterior vertebral column in operative treatment of advanced traumatic and neoplastic changes of the thoraco-lumbar spine]. / Jednoczesny przedni i tylny dostep w operacyjnym leczeniu nowotworów oraz pourazowych znieksztalcen kregoslupa piersiowego i ledzwiowego.

There were presented indications and operative technique of one-stage approach to anterior and posterior part of the thoraco-lumbar spine. Presented technique gave chance to control antero-lateral and posterior aspects of the spine. There were 2 patients with delayed compressions of the vertebral bodies in lumbar part with severe kyphotic deformity. Those deformities were the cause of progression of neural symptoms in a few months after injury. Another 4 patients had the spinal tumours. In one case it was giant-cell tumour which destroyed body and the arch of Th12. In two patients metastases of renal cancer infiltrated L2 and L3. The last one had breast cancer metastasis into Th12. In all patients it was necessary to control anterior and posterior columns of the spine to restore its axis and the shape of spinal canal.

Radiological assessment of indications for surgical treatment of spinal metastases.

Background. The purpose is to assess the risk of spinal cord compression in patients with spine metastases using radiological data.
Material and methods. We evaluate 103 patients with the thoraco-lumbar vertebral body metastases - 52 with neurological symptoms of spinal cord compression and 51 symptoms free. We measured the statistical relation between spinal cord compression, pathological fracture, angle deformity of the spine and metastasis location. We divide spine into 3 columns and named pediculum as the fourth. We used statistical multiple regression analysis.
Results. The risk of spinal cord compression is depended on the location of the metastasis in vertebral body (p < 0,01). We found spinal cord compression symptoms in 25 out of 31 patients in group with pediculum involvement and in 27 out of 72 in group with other locations. It was highly statistically important (p < 0.001). In 45 out of 68 patients with vertebral fractures we found spinal cord compression symptoms (p < 0.01). We did not found statistical correlation between angle deformity and compression symptoms.
Conclusions. The risk of spinal cord compression is higher if the metastases are localised in thoraco-lumbar part of spine and if the pediculum is involved. The pathological fracture increases the risk of the compression, too.

[Repair of focal chondral lesions of femoral condyles treated with osteochondral autografts]. / Naprawy ogniskowych uszkodzen chrzastki stawowej klykci kosci udowych autogennymi przeszczepami chrzestno-kostnymi.

A series of 15 patients with focal chondral lesions of the femoral condyles were treated at the Orthopaedics Department of the University of Medical Sciences of Lublin between 1998-2000. The patients' age varied from 20 to 72 years and the follow-up period from 6 months to 2.5 years. Osteochondritis dissecans was observed in 9 patients. Articular cartilage defects associated with chronic ligament instability was noted in 5 cases and 1 patient suffered from a chondral fracture of the lateral femoral condyle during a traumatic luxation of the patella. The depth of the lesions was graded according to ICRS scale. Grade IV was found in 11 cases and the remaining 4 cases had grade III lesions. The defects were treated with osteochondral autografts using OATS instrumentation set. Results were prospectively evaluated according to the HSS score. The preoperative value of HSS score ranged from 28 to 51 points (average 40.3). During follow-up the score values ranged from 76 to 91 points (average 84.7 points). All patients regained full range of motion in the knee, although in one case arthroscopic release of intraarticular adhesions was performed 6 months after chondroplasty. The lowest HSS values at follow-up were found in elderly patients with concomitant mild degenerative changes in the lateral knee compartment and in the patello-femoral joint. All patients had MRI examination early post-op, then after 6, 12 and 24 months from the procedure. MRI confirmed proper structure of the grafted cartilage but bony parts of the graft did not integrate with the surroundings.

[Evaluation of the anterior cruciate ligament injury treatment results using patellar tendon grafts]. / Ocena wyników leczenia uszkodzen wiezadel krzyzowych przednich przy uzyciu przeszczepów 1/3 srodkowej wiezadla rzepki.

The analysed material consisted of 38 cases of chronic knee insufficiency because of anterior cruciate ligament injury. Patients were divided into 2 groups. The first group (18 patients) was treated with 1/3 patellar tendon graft (B-T-B) stabilised by sutures on either screws or staples with a 4-5 week immobilisation period post-op. The second group (20 patients) had graft fixation with interferential screws and no post-op immobilisation. Statistically significant better results were achieved in the group treated with interferential screws. The results were evaluated using HSS and Lysholm and Gillquist rating scores.