Biomedical subjects

Serhat Ozsoy

Publications and source records attributed to Serhat Ozsoy.

4 recordsLinked to original sources

PubMed2005

Time-dependent changes in failure loads of 3 biceps tenodesis techniques: in vivo study in a sheep model.

BACKGROUND: Failure load of the tendon-fixation material-bone unit has a crucial importance for the rehabilitation protocol after tenodesis procedures. PURPOSE: To investigate and compare the time-dependent changes in fixation strengths of 3 proximal biceps tenodesis techniques. STUDY DESIGN: Controlled laboratory study. METHODS: Two intraosseous techniques (suture sling and tenodesis screw) and 1 extraosseous technique (2 suture anchors) were investigated. Biceps tenodesis was performed on 45 shoulders of 26 sheep, 15 shoulders for each technique. Twelve similar cadaveric sheep shoulders (4 for each technique) provided the day 0 results. Sheep were sacrificed at 3, 6, and 9 weeks, and specimens were tested for the failure load of the tenodeses. RESULTS: All 3 tenodesis techniques were found to have similar failure loads at all time intervals tested. All 3 curves remained below the failure load of the intact tendon (862 +/- 96 N) and above their day 0 results for the study period; similarly, at each time interval, results tended to be better compared to the previous test. The tenodesis screw group exhibited significantly higher failure loads at week 3 (419 +/- 53 N) compared to day 0 values (164 +/- 45 N) (P = .009). The same level of significance was observed at week 6 in the remaining 2 groups. CONCLUSION: Tenodesis of the biceps tendon on the proximal humerus at an extra-articular site does not weaken after surgery. The tenodesis screw group had a significantly higher increase in the fixation strength within the first 3 weeks. CLINICAL RELEVANCE: No significant differences could be found between the failure loads of all 3 investigated tenodeses for the first 9 weeks.

Absorbable Implants↗

PubMed2004

Semirapid maxillary expansion--a study of long-term transverse effects in older adolescents and adults.

A new approach, namely, semirapid maxillary expansion (SRME) was introduced with the hypothesis that SRME may stimulate the adaptation process in the nasomaxillary complex and thus would result in reduction of relapse in the postretention period. The aim of this study was therefore to evaluate the short- and long-term effects of SRME on dentofacial structures in older adolescents and adults. The study sample consisted of 40 individuals, 20 orthodontic patients who required maxillary expansion and 20 control cases who received no orthodontic treatment. The mean ages were 14.57 and 13.83 years at the start of treatment and control periods, respectively, and ranged between MP3cap and Ru hand-and-wrist maturation stages. A rigid acrylic maxillary expander was used for SRME (RME of 5-7 days, followed by slow maxillary expansion). The mean expansion time was 0.34 years, and the mean follow-up period was 2.68 years after retention. PA cephalometric film measurements were performed, and the data were analyzed statistically by using paired and Student's t-tests. Lower nasal and maxillary base widths, and upper intermolar and incisor interapex widths were significantly increased compared with the control group (P < .05, P < .001) and remained unchanged during the retention and follow-up stages. Moreover, significant amount of increases occurred in zygomatic and lower nasal widths during the follow-up period. The findings of this study suggested that the dentoskeletal changes after the use of SRME were maintained satisfactorily in the long term in older adolescents and adults.

Adolescent↗

PubMed2003

Failure strength of bioabsorbable interference screws: effects of in vivo degradation for 12 weeks.

We investigated the effect of in vivo degradation for 6-12 weeks on the fixation strength of polylactide bioabsorbable interference screws. Ten bioabsorbable interference screws were used to fix the patellar tendon autograft in ten live sheep knees, which were equally divided into two groups and killed in the 6th or 12th week. The control group consisted of four cadaveric knees. Following the killing of the animals the screws were retrieved and reused to fix patellar tendon grafts in cadaveric sheep knees. Tendon pull-out tests were performed for the partially degraded screws, for the control group, and for the reused screws of the control group. Macroscopic and microscopic examinations of the 6- and 12-week specimens were performed. Tendons pulled-out with an average force of 357+/-30 N in the cadaveric control group on the first use and with 465+/-118 N on the second use. The partially degraded screws failed with a mean load of 399+/-119 N in the 6-week group, and 12-week screws at 447+/-72 N. No macroscopic sign of degradation was observed on the retrieved screws. Histological examination of the 6 week specimens showed necrotic changes in the tendon around screw contact areas. Healing with granulation tissue was present in the same area in the 12th week. Foreign body reaction or an excessive inflammatory reaction was not observed. In vivo degradation of poly- l-lactide interference screws for 12 weeks thus causes neither a loss in the fixation strength of the screws nor an obvious inflammatory reaction.

Absorbable Implants↗

PubMed2003

Low-cost antibiotic loaded systems for developing countries.

Treatment of osteomyelitis with local antibiotic delivery systems has become a common practice in orthopaedic surgery. This study attempted to show that locally produced pure or bioglass reinforced plaster of Paris, hydroxyapatite and sodium alginate are promising biomaterials and mainly because of economical reasons and availability, may be an alternative in clinical practice, especially for developing countries. A total of 32 rabbits were divided into four groups (n:8). In group A, sodium alginate + cephazoline; in group B, plaster of Paris + bioglass + cephazoline; in group C, plaster of Paris + hydroxyapatite + cephazoline and in group D, plaster of Paris + cephazoline were used. The blood serum cephazoline concentrations were analyzed by high performance liquid chromatography on days 1 to 10 everyday and then at days 13, 17, 18, 24, 25 and 30. The mean values +/- standard deviations and median values of blood serum antibiotic concentrations for groups A, B, C and D were 1.45 +/- 0.40 (1.42) mcg/ml, 1.53 +/- 0.64 (1.31) mcg/ml, 1.92 +/- 0.39 mcg/ml (1.90) and 1.41 +/- 0.65 (1.25) mcg/ml, respectively. The detected antibiotic level was constantly over the minimum inhibitory concentration for Staphylococcus aureus. In conclusion, it can be stated that these materials are promising as a antibiotic delivery system even with simple production methods.

Alginates↗