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Biomedical subjects

O S Atik

Publications and source records attributed to O S Atik.

11 recordsLinked to original sources
PubMed2001

Histological and magnetic resonance imaging alterations after irradiation of meniscus using Holmium:YAG laser.

OBJECTIVE: The authors performed an experimental and a prospective clinical study to evaluate the histological and magnetic resonance imaging (MRI) alterations after irradiation of meniscus using holmium:YAG (Ho:YAG) laser VersaPulse Select 60 watts and InfraTome Delivery Systems 30 degrees Handpiece (spot size at fiber tip 0.4 mm; Coherent Medical, Palo Alto, CA). BACKGROUND DATA: Recently, some authors reported a few cases with articular cartilage damage or paraarticular osteonecrosis following arthroscopic knee surgery in which the laser was used to assist in the treatment of meniscal pathology. METHODS: Meniscus specimens in saline immersion were exposed to Ho:YAG laser irradiation. The laser wavelength was 2.1 microm and pulse duration was 250 microsec. Power settings were 1-1.5 joules per pulse and 10-15 Hz. Total laser energy used in these procedures was 2, 3.5, and 6 K joules. Eight patients with meniscal problems underwent arthroscopic partial meniscectomy using Ho:YAG laser. Total laser energy used for these surgeries was 1.5-2.5 K joules. MRI was performed preoperatively and at 6 months postoperatively. RESULTS: At higher energy levels (more than 3 K joules), separation of the gap between the collagen fibers, and a three-dimensional dispersion in the striation were observed on electron microscopic evaluation of meniscus specimens. No patient had abnormal signals in MRI (a sign of articular cartilage damage or osteonecrosis) following arthroscopic laser surgery. CONCLUSION: When higher energy level is required, conventional instruments should be preferred in the treatment of meniscal lesions. Laser should be reserved for the posteriorly located and smaller meniscal lesions.

Holmium↗
PubMed2001

Surgical repair of cartilage defects of the patella.

The structure and biomechanical forces on the patellar joint challenges researchers to define an ideal method for resurfacing the patellar cartilage. The articular surface of the patella presents variability between individuals, and has various minor articulations that bear partial or total compressive, shear, and combined forces during movement. Surgical techniques for the repair of patellar cartilage defects have evolved from cumulative advances in basic science and technology. Such surgeries include the techniques that promote either fibrocartilage formation or hyalinelike cartilage formation. Techniques promoting the formation of fibrocartilage yield short-term solutions because fibrocartilage lacks the durability and the mechanical properties of articular hyaline cartilage. Currently, there is no ideal method for the repair of patellar cartilage defects; all methods are considered experimental. Additional controlled and randomized clinical studies with large series of patients and long-term followup are required.

Cartilage Diseases↗
PubMed1999

Prevention of oxidative stress due to tourniquet application. Analysis of the effects of local hypothermia and systemic allopurinol administration.

In this study various methods for the prevention of oxidative stress due to tourniquet application were compared. An ischemia period of two hours followed by a reperfusion period of one hour was produced in the right posterior limb in 32 rats. In the first group no treatment was given. In the second group local cold application was performed before and after ischemia. In the third group allopurinol was given orally for 5 days before the procedure. In the fourth group both local hypothermia application and oral allopurinol treatment were given. Ultrastructural study of the gastrocnemius muscles in the various groups revealed that the least damage in the ultrastructure of the striated muscle was obtained using allopurinol alone and using a combination of allopurinol and local hypothermia. When tissue glutathione levels were measured, it was seen that a combination of allopurinol and local hypothermia was the best treatment for preventing oxidative stress.

Administration, Oral↗
PubMed1999

Bicompartmental knee replacement and patellar resurfacing. A prospective study with a minimum follow-up of ten years.

We avoid routine patellar resurfacing during knee replacement because of the risk of major complications. We undertook a prospective study to evaluate the functional outcome of the patients who had no patellar resurfacing. Eleven patients (17 knees) who met the criteria for inclusion participated in the study. The preoperative diagnosis was osteoarthritis in all patients. A lateral retinacular release was performed when necessary. The knees were evaluated using the Hospital for Special Surgery knee scoring system. The mean follow-up was 10.5 years (range: 10 to 10.8 years). The average HSS score raised from 40 points to 83 points. The mean postoperative range of motion of the knee joint was 105 degrees. Postoperative radiographic evaluation revealed that there was no correlation between the integrity of the cartilage and the degree of pain. We concluded that patellar resurfacing is not a routine procedure in knee replacement when the diagnosis is osteoarthritis.

Aged↗
PubMed1999

Does the Holmium:Yag laser cause osteonecrosis?

Some authors have reported a few cases of paraarticular osteonecrosis following arthroscopic knee surgery in which laser was used to assist in the treatment of cartilage and meniscal pathology. We performed a prospective randomized clinical study to determine if osteonecrosis occurs after arthroscopic laser surgery. Fifty-five patients with cartilage problems in their knee joints were randomized into two groups: the laser group included 30 patients and the conventionally instrumented group consisted of 25 patients. Power settings for the Holmium:YAG laser were 0.5 to 1.5 joules per pulse and 5 and 25 Hertz. Total energy used for the procedures was 1 to 2 K joules. Magnetic resonance imaging was performed on all patients preoperatively and postoperatively (in third, sixth, and thirteenth months). None of the patients had osteonecrosis following arthroscopic laser surgery. When the Holmium:YAG laser is used at an optimal dosage (optimal joule and Hertz) with an optimal technique (keeping the handpiece at an appropriate angle and distance) and for an optimal time (avoiding overtreatment), it does not cause osteonecrosis.

Arthroscopy↗
PubMed1995

Relevance of mangled extremity severity score to compartment syndromes.

This study investigated the relevance of a mangled extremity severity score (MESS) to the evaluation of intracompartmental pressure in injured patients. We measured intracompartmental pressures with a modification of the Whitesides method and compared these values with MESS in 27 patients after trauma. For 5 of them fasciotomy was necessary to relieve high intracompartmental pressures. In our series MESS seemed to correlate with intracompartmental pressure values (r = 0.733, P < 0.05). We conclude that the MESS system provides objective criteria in determining the risk of a compartment syndrome.

Adolescent↗
PubMed1983

Prostaglandin E2 - like activity and senile osteoporosis.

Prostaglandin E2-like activity in bone samples from patients with senile osteoporosis was determined and found higher than in samples obtained from normal patients. The results suggest that endogenous prostaglandins may have a role in the pathogenesis of senile osteoporosis.

Aged↗
PubMed1983

Zinc and senile osteoporosis.

The zinc ion levels in serum and bone tissue of patients with senile osteoporosis were determined and found to be less than that obtained from normal patients. The results suggest that zinc depletion may have a role in the pathogenesis of senile osteoporosis.

Aged↗
PubMedDate not supplied

Determination of tibial torsion by computed tomography.

Torsional malalignment of the lower extremity, especially during childhood, is a common concern and even an anxiety to the parents. Torsional deformity may be seen at one or more sites, and tibial torsion is a frequent cause of this problem. Medial femoral torsion and metatarsus adductus also affects the alignment of the extremity. Although a corrective osteotomy for tibial torsion is performed very rarely, the precise determination is mandatory. Tibial torsion and the torsion of the leg was measured in 25 adults by computed tomography. The inclination between the dorsal tangent to the tibial condyles and the distal reference line was considered as tibial torsion. The distal reference line was formed with intersection of centers of medial and lateral malleoli. While measuring the torsion of the leg, tangent dorsal to the femoral condyles was used for proximal reference line. In the females, the average of tibial torsion was 31.07 degrees for the right side and 30.02 degrees for the left. For the males, the averages were 32.7 and 35.26 degrees for the right and left sides, respectively.

Adolescent↗
PubMedDate not supplied

Pachydermoperiostosis: a case report.

Pachydermoperiostosis in three males of seven siblings from a village of mid-Anatolia is presented. Although X-linkage could not have been ruled out, the autosomal recessive inheritance was considered most likely. It differs from the autosomal dominant form by growth retardation, early ulcers, and acrolysis of the distal parts of the extremities with secondary contractures.

Adolescent↗