Biomedical subjects

Cengiz Sen

Publications and source records attributed to Cengiz Sen.

At least 19 recordsLinked to original sources

PubMed2007

Effects of diclofenac and tenoxicam on distraction osteogenesis.

INTRODUCTION: In the management of bone defects, pseudoarthrosis, deformities, chronic osteomyelitis and in extremity lengthening procedures, the technique of distraction osteogenesis (DO) has been frequently used. In this experimental animal study, the effects of two non-steroidal anti-inflammatory drugs, i.e., diclofenac and tenoxicam, on the outcomes of distraction osteogenesis are investigated. MATERIALS AND METHODS: In this study, 30 mature New Zealand-type male rabbits (2.5-4.5 kg) were used. The rabbits were randomized into three groups, each consisting of ten animals. Under optimal operating conditions, a pre-reconstructed circular external fixator was applied on the right tibias of rabbits, and osteotomy was performed with a Gigli saw just below the tibial tuberosity. After seven postoperative days, distraction was initiated at a rhythm of 2 x 0.5 mm/day. During the 10 days of distraction, adjunctive therapy was not instituted for group I (control group). For 10 days, group II received i.m. diclofenac sodium (0.5 mg/kg per day) and group III was treated with tenoxicam (8 mg/kg per day i.m.). At the end of 3 weeks postoperatively, five rabbits from each group were killed for histologic examinations. The remaining rabbits were killed at the end of eight postoperative weeks for biomechanical and histological analysis. Besides, radiological examinations were performed at the end of 3, 6 and 8 weeks postoperatively for the radiologic evaluation of calluses. For statistical evaluations between groups, Kruskal-Wallis variance analysis, and for intergroup assessments, Mann-Whitney test were performed. RESULTS: For radiological evaluations, the scoring system developed by Lane and Sandhu, and for histopathological assessments, the grading system of Huddlestone et al. were used. Biomechanical tests were realized using torsional loading. During the first 3 weeks, the groups did not differ much in the radiological parameters. However, in the diclofenac group and in especially the tenoxicam group, the histological scores were lower than in the control group. Radiological images obtained at the end of 6 weeks demonstrated inadequate consolidation in the diclofenac and tenoxicam groups when compared with the control group. At the end of 8 weeks postoperatively, in consideration of biomechanical, radiological and histological tests, significantly worse regenerates were obtained in the diclofenac and tenoxicam groups. CONCLUSIONS: During the distraction osteogenesis period, diclofenac and tenoxicam affected the quality of regenerate unfavorably. This effect is sustained during all periods of bone healing. However, this finding should be supported by experimental and human studies.

Animals↗

PubMed2006

Ferroelectricity in the magnetic E-phase of orthorhombic perovskites.

We show that the symmetry of the spin zigzag chain E phase of the orthorhombic perovskite manganites and nickelates allows for the existence of a finite ferroelectric polarization. The proposed microscopic mechanism is independent of spin-orbit coupling. We predict that the polarization induced by the E-type magnetic order can potentially be enhanced by up to 2 orders of magnitude with respect to that in the spiral magnetic phases of TbMnO3 and similar multiferroic compounds.

Journal Article↗

PubMed2006

Polygonal triple (Kotz) osteotomy (over 10 years experience).

We evaluated the results of polygonal triple (Kotz) osteotomy for the treatment of acetabular dysplasia over 10 years. This study included 31 hips of 27 patients who had the Kotz osteotomy for acetabular dysplasia. The mean age was 21.5 years. We performed the original Kotz osteotomy for the first 22 hips (group I), while the modified Kotz osteotomy through an intra-pelvic approach without damage to the abductor muscle was applied for the last 9 hips (group II). Patients were evaluated by clinically and radiologically. The average follow-up was 106 months in group I, and 18 months in group II. The Trendelenburg gait was unchanged for four patients in group I and for one patient in group II. The Harris Hip Score improved in all patients postoperatively. Radiographic assesment showed improvement in both groups in terms of the angle of CE, VCE, and Sharp postoperatively(P<0.05). The complication rate per hip was 0.29. The original Kotz osteotomy achieves adequate coverage for the treatment of acetabular dysplasia, and patients are generally satisfied by this procedure. Nonetheless, the modified Kotz osteotomy provides recovery of the abductor muscle strength in the early postoperative period and subsequently decreases the rate of the Trendelenburg gait compared to the original Kotz osteotomy.

Adolescent↗

PubMed2006

Tibial slope and high tibial osteotomy using the circular external fixator.

Alteration of tibial slope is one of the important anatomical changes of the proximal tibia after high tibial osteotomy. Increased or decreased tibial slope can effect further total knee prosthesis procedure. In this retrospective study, 18 knees of 17 patients (17 female, mean age 51 range 43-61, mean BMI is 33.6 +/- 4.6 kg/m2) who were applied high tibial osteotomy using circular external fixator due to medial compartment arthrosis of the knee were evaluated in terms of tibial slope changes. While mean correction about 12.3 degrees in mechanical femoro-tibial angle was obtained in frontal plan (P = 0.0001), significant change in tibial slope was not determined in sagittal plan (P = 0.127). The mean posterior proximal femoral angle values were measured as 79.5 +/- 2.1 degrees preoperatively and as 80.3 +/- 2.7 degrees postoperatively and found to fall into the normal range (80.4 +/- 1.6 degrees). As there is no significant alteration in tibial slope after high tibial osteotomy performed with the Ilizarov system, complications due to alteration in tibial slope will not be experienced in follow-up or in further total knee prosthesis procedure.

Adult↗

PubMed2006

High tibial osteotomy with Puddu plate for the treatment of varus gonarthrosis.

In this study, the results of open-wedge osteotomy with Puddu plate for the treatment of varus gonarthrosis have been evaluated prospectively. This study assessed 65 knees of 60 patients with varus gonarthrosis who underwent high tibial osteotomies. Our study population consisted of 13 male and 47 female patients with a mean age of 54 (range 39-76) years. For the clinical evaluation of the patients Hospital of Special Surgery (HSS) score, American Knee Society and Oxford knee scores, and for the radiological assessment mechanical axis deviation (MAD), lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), femorotibial angle and Insall-Salvati index were basically taken into consideration. Our patients were followed up for an average of 34 (range 18-60) months. In the last assessments of our cases, mean improvements detected in HSS scores, Oxford knee scores, knee and functional scores of Knee Society were 26.72, 19.18, 49.9, and 30 points, respectively. The radiological examinations revealed that their mechanical axes on the average passed 5.09 mm laterally achieving an average of 6.5 degrees genu valgum, and a mean Insall-Salvati index of 1.09. As complications, superficial wound infection in two patients (3%), implant infections in one patient (1.5%), deep vein thrombosis in two patients (3%), peroperative lateral tibial plateau fracture in one patient (1.5%), and postoperative lateral tibial plateau fracture due to a falling down were encountered. According to the results obtained, postoperative pain resolves promptly and a significant degree of improvement of knee functions of the patients are achieved. Therefore, we believe that high tibial osteotomy with a Puddu plate is a valuable alternative to total knee arthroplasty in cases with varus gonarthrosis. Although early results are satisfactory, long-term follow-up studies are required especially in the middle aged and elderly patient populations.

Adult↗

PubMed2006

Effects of calcitonin and alendronate on distraction osteogenesis.

In this experimental animal study the effects of calcitonin and alendronate on distraction osteogenesis are investigated. Forty-five mature female New Zealand type rabbits were used. Rabbits were randomized into three groups, each consisting of 15 animals. Under optimal operating conditions a pre-reconstructed circular external fixator was applied to the right tibia of rabbits, and osteotomy was performed with a Gigli saw just below the tibial tuberosity. During the ten days of distraction, a placebo was administered for group I (control group), group II received 10 U of calcitonin, and group III was treated with alendronate (0.5 mg/kg/day) gavages. Rabbits were examined histologically (at the third and eighth weeks, according to Huddlestone et al.), radiologically (at the third, sixth, and eighth weeks, according to Lane and Sandhu), and mechanically (at the eighth week, as torsional loading). During the first three weeks, the groups did not differ much with regard to radiological parameters. However, in the calcitonin and alendronate groups improved histological scores were detected compared with the control group. Radiological images obtained at the end of six weeks demonstrated improved consolidation in the calcitonin and alendronate groups compared with the control group. At the end of eight weeks postoperatively, radiological and histological parameters did not differ among the groups, while torsional failure load was found to be much improved in the calcitonin group (p=0.006). During the distraction osteogenesis period, calcitonin and alendronate affected the quality of regenerate favourably. This effect is sustained until the end of the consolidation period. However, this finding needs to be supported by experimental and human studies.

Alendronate↗

PubMed2006

Reconstruction of segmental bone defects due to chronic osteomyelitis with use of an external fixator and an intramedullary nail.

BACKGROUND: Callus distraction over an intramedullary nail is a rarely used technique for the reconstruction of intercalary defects of the femur and tibia after radical débridement of chronic osteomyelitic foci. The aim of this study was to summarize our experience with distraction osteogenesis performed with an external fixator combined with an intramedullary nail for the treatment of bone defects and limb-shortening resulting from radical débridement of chronic osteomyelitis. METHODS: Thirteen patients who ranged in age from eighteen to sixty-three years underwent radical débridement to treat a nonunion associated with chronic osteomyelitis of the tibia (seven patients) and femur (six patients). The lesions were classified, according to the Cierny-Mader classification system, as type IVA (nine) and type IVB (four). The resulting segmental defects and any limb-length discrepancy were then reconstructed with use of distraction osteogenesis over an intramedullary nail. Two patients required a local gastrocnemius flap. Free nonvascularized fibular grafts were added to the distraction site for augmentation of a femoral defect at the time of external fixator removal and locking of the nail in two patients. At the time of the latest follow-up, functional and radiographic results were evaluated with use of the criteria of Paley et al. RESULTS: The mean size of the defect was 10 cm (range, 6 to 13 cm) in the femur and 7 cm (range, 5 to 10 cm) in the tibia. The mean external fixator index was 13.5 days per centimeter, the consolidation index was 31.7 days/cm, and the mean time to union at the docking site was nine months (range, five to sixteen months). At a mean follow-up of 47.3 months, eleven of the thirteen patients had an excellent result in terms of both bone and functional assessment. There were two recurrences of infection necessitating nail removal. These patients underwent revision with an Ilizarov fixator. Subsequently, the infection was controlled and the nonunions healed. CONCLUSIONS: This combined method may prove to be an improvement on the classic techniques for the treatment of a nonunion of a long bone associated with chronic osteomyelitis, in terms of external fixation period and consolidation index. The earlier removal of the external fixator is associated with increased patient comfort, a decreased complication rate, and a convenient and rapid rehabilitation.

Adolescent↗

PubMed2006

[Combination of microfracture and periosteal transplantation techniques for the treatment of full-thickness cartilage defects].

OBJECTIVES: Microfracture and periosteal transplantation techniques were combined in order to enhance the quality of repair for the treatment of full-thickness cartilage defects. METHODS: In 40 mature New Zealand white rabbits, a full-thickness cartilage defect of 4 mm was induced on the weight-bearing surfaces of the medial condyles of the right femur. The rabbits were randomly divided into four groups equal in size. Control animals remained untreated following defect induction. Two groups were either treated with periosteal transplantation or the microfracture technique, while the fourth group underwent combination of the two techniques. All the animals were immobilized for two weeks postoperatively. At the end of 12 weeks, the animals were sacrificed and the specimens were removed for evaluation according to the criteria of the ICRS scale (International Cartilage Repair Society), and with respect to newly regenerated cartilage areas and the number of viable chondrocytes. RESULTS: Specimens treated with the combination of the two techniques exhibited significant differences from the other groups in all criteria of the ICRS scale (surface, matrix, cellular distribution, cell viability, and cartilage mineralization) except for subchondral bone criteria. In addition, the mean number of viable chondrocytes and newly regenerated cartilage areas were the highest in this group (p=0.0001). CONCLUSION: Due to markedly improved quality of repair, the combination of the microfracture and periosteal flap techniques seems to be more effective than either of the techniques used alone in the treatment of cartilage defects.

Animals↗

PubMed2006

[Atraumatic bilateral patellar tendon rupture in a patient receiving steroid therapy].

Atraumatic bilateral patellar tendon rupture is a rare entity. It is usually due to systemic or local disorders causing tendon degeneration. Early diagnosis and surgical treatment are crucial for recovery of knee functions. Atraumatic bilateral patellar tendon rupture was diagnosed in a 31-year-old female patient who had been receiving steroid therapy for seven years due to systemic lupus erythematosus. She underwent patellar tendon reconstruction with the use of semitendinosus and gracilis tendons. After a follow-up of six months, she could walk without crutches and had a full range of motion.

Adult↗

PubMed2005

Phase fluctuations in strongly coupled d-wave superconductors.

We present a numerically exact solution for the BCS Hamiltonian at any temperature, including the degrees of freedom associated with classical phase, as well as amplitude fluctuations via a Monte Carlo integration. This allows for an investigation over the whole range of couplings: from weak attraction, as in the well-known BCS limit, to the mainly unexplored strong-coupling regime of pronounced phase fluctuations. In the latter, two characteristic temperatures T(*) and T(c), associated with short- and long-range ordering, respectively, can be identified in a mean-field-motivated Hamiltonian. T(*) at the same time corresponds to the opening of a gap in the excitation spectrum. In addition to introducing a novel procedure to study strongly coupled d-wave superconductors, our results indicate that classical phase fluctuations are not sufficient to explain the pseudogap features of high-temperature superconductors.

Journal Article↗

PubMed2005

[A case of congenital pseudarthrosis of the clavicle].

Congenital pseudarthrosis of the clavicle is a rare condition of unknown etiology. It usually presents as a painless mass in the clavicular region; however, it may sometimes be associated with pain and weakness in the shoulder. We presented a 21-year-old male patient who had pain and weakness in the right shoulder during sportive and daily vigorous activities due to congenital pseudarthrosis of the clavicle. The patient was successfully treated by excision of the ends of the medial and lateral fragments, reconstruction of the defect with a tricortical iliac crest autograft, and internal fixation of the clavicle with a plate and bone screws. After seven months postoperatively, his complaints disappeared, with a full range of motion and Constant score.

Adult↗

PubMed2004

Knee arthrodesis using circular external fixator in the treatment of infected knee prosthesis: case report.

A patient (68 years old and male) underwent total knee replacement because of arthrosis, but he subsequently had infection due to a wound problem. Although he underwent early debridement, antibiotherapy, and soft-tissue operation, treatment failed because of improper soft-tissue coverage and progression of the infection. Therefore, the prosthesis was removed and a spacer with antibiotic was placed, in order to provide soft-tissue coverage and to eradicate infection. After 2 months, the patient underwent knee arthrodesis using a circular external fixator to achieve a stable lower extremity and to facilitate return to activities of daily living. We obtained knee fusion at 4 months without any requirement for secondary procedure of soft tissue and bone graft. There was no major complication. Arthrodesis with circular external fixator is a reliable and successive method that should be preferred for the treatment of infected knee replacement.

Aged↗

PubMed2004

Bifocal compression-distraction in the acute treatment of grade III open tibia fractures with bone and soft-tissue loss: a report of 24 cases.

OBJECTIVE: To evaluate the results of bifocal compression-distraction method for the acute treatment of open tibia fractures with bone and soft-tissue loss. DESIGN: Patients were selected for bifocal compression-distraction (shortening and lengthening) who had open tibia fractures with bone and soft-tissue loss and a Mangled Extremity Severe Score of 6 and below indicating good leg viability. PATIENTS: Bifocal compression-distraction osteogenesis using the Ilizarov type circular external fixator was applied to 24 patients with 14 grade IIIA and 10 grade IIIB open tibia fractures with bone and soft-tissue loss. Mean age of the patients was 30.6 years (range 18-53). The mean bone defect was 5 cm (range 3-8.5). The mean soft tissue defect was 2.5 x 3.5 (1 x 2-10 x 5) cm. INTERVENTIONS: Acute shortening at the fracture site was done for patients with bone defects up to 3 cm to achieve apposition of bone ends. Gradual shortening at a rate of 2 mm/d was done for patients who had bone defects more than 3 cm. Leg length discrepancy was overcome by lengthening at the same time through a corticotomy at a proximal or distal level depending on fracture localization, until there was equalization of leg lengths. RESULTS: Mean follow-up period was 30 months (range 18-60). Mean bone healing time was 7.5 months (range 4-11). The mean time in external fixation was 7.1 months (range 3-10), and the average external fixator index was 1.4 months/cm. Results were evaluated using the Paley bone and functional assessment scores. The bone assessment results were excellent in 21 and good in 3 patients. Functional assessment scores were excellent in 19, good in 4, and fair in 1 patient. Pin site infections were present in 10.7% of the pin sites. There were 52 complications in 24 patients, for a complication rate per patient of 2.08. Of the complications, 48.1% were problems (minor complications), 38.5% obstacles (major complications requiring a surgical solution), and 13.4% sequelae (true complications). Minor complications included soft tissue inflammation and infection, translation/angulation, and delayed maturation during distraction and transient knee contracture and loss of motion. All grade 1 and 2 soft tissue inflammations and infections healed with nonoperative therapy. Major complications included pin tract infection and reinfection, equinus deformity, frame failure, and premature consolidation, all of which required additional surgery to correct the problem. Sequelae included leg length discrepancy, loss of knee/ankle range of motion, knee flexion contracture, malalignment, and chronic osteomyelitis. CONCLUSION: Bifocal compression-distraction osteogenesis is a safe, reliable, and largely successful method for the acute treatment of open tibia fractures with bone and soft-tissue loss. Further nonoperative or operative treatment can correct most complications.

Adolescent↗

PubMed2004

[The chondroprotective effect of intra-articular hyaluronic acid at early stages of osteoarthritis: an experimental study in rabbits].

OBJECTIVES: Hyaluronic acid (HA) is used in osteoarthritis, especially for the control of pain. In this study, we investigated the effect of intra-articular HA on experimental osteoarthritis of early stage. METHODS: Osteoarthritis was induced in both knees of 10 rabbits by transecting the anterior cruciate ligament under intramuscular anesthesia with ketamine and xylazine. Intra-articular HA at a dose of 0.6 ml (15 mg/ml) and physiologic saline solution (0.6 ml) were injected into the right and left knees, respectively, three times with a week interval. Three rabbits died during the study period and were excluded. The remaining rabbits were sacrificed in the 12th week via high dose anesthesia to remove the distal femora for histological evaluation using the Mankin scale and for measurements of the cartilage area. RESULTS: The mean cartilage areas calculated in HA- and saline-injected knees differed significantly (1.097 mm2 and 0.477 mm2, respectively; p<0.05). The overall mean Mankin score was significantly lower in HA-injected knees (3.57 versus 11.14; p<0.05). Although, there were no significant differences between the two groups with respect to cellular abnormality, matrix staining, and tidemark continuity (p>0.05), the mean scores for the structure of the cartilage were significantly different (0.86 versus 4.43; p<0.05). The integrity of the tidemark was preserved in all the HA-administered knees, though a notable disruption was observed in four control knees. CONCLUSION: Our results suggest that HA delays the development of osteoarthritis at early stages through exerting a chondroprotective effect.

Adjuvants, Immunologic↗

PubMed2003

The advantages of circular external fixation used in high tibial osteotomy (average 6 years follow-up).

We evaluated the midterm results of high tibial osteotomy in patients with medial compartment arthritis. This study included 53 patients treated with high tibial osteotomy accompanied by either internal fixation (group A, n=26) or Ilizarov-type external fixator (group B, n=27). Clinical assessment of patients was performed using Hospital of Special Surgery scoring. Radiography was based on orientation angles of the knee (medial proximal tibial angle, lateral distal femoral angle, posterior proximal tibial angle) and mechanic axis alignment test. We used the Insall-Salvati index to determine patellar height. The mean follow-up in group A was 77 months (range 63-118) and that in group B 72 months (range 61-113). The patients of group B demonstrated better results in terms of Hospital of Special Surgery score, alignment of lower extremity, and preventing of progression of arthritis. We believe that normal alignment and orientation of the knee could be precisely established with a circular external fixator, and that some disadvantages such as patella infera, failed correction, and loss of bone in proximal tibia as observed after classic high tibial osteotomy can be avoided. Furthermore, progression of arthritis can be prevented if the mechanical axis passes through the lateral compartment of the knee.

Adult↗

PubMed2003

Discoid lateral meniscus: diagnosis and results of arthroscopic treatment.

We evaluated the results of arthroscopic meniscectomy in patients with discoid lateral menisci of the knee. Discoid lateral menisci were detected in 308 patients, of whom 197 (124 males, 73 females; mean age 34.5 years, range 6-67) were clinically, radiologically, and arthroscopically found to be symptomatic and underwent partial meniscectomy. The average period between injury and operation was 13.2 months (range 6-52). The results were evaluated according to the Ikeuchi and Lysholm criteria. The mean follow-up was 57.8 months (range 24-138). The most common complaints were pain (66%) and joint line tenderness (61%). Widening of lateral joint space was the most common radiological finding (25%). The confirmation of diagnosis by magnetic resonance imaging was not congruent with arthroscopic results for some patients (31%). According to the Ikeuchi criteria, the results were excellent in 110 patients (56%), good in 53 (27%), fair in 26 (13%), and poor in 8 (4%). On the other hand, according to the Lysholm scale, the results were excellent in 119 patients (60%), good in 57 patients (29%), fair in 16 (8%), and poor in five (3%) patients. Clinical and radiological findings were not congruent with arthroscopic results for all patients. Therefore arthroscopic evaluation has more value for discoid lateral meniscus. Moreover, tear pattern and degenerative changes in lateral compartment may effect outcomes without relation to the type of surgery. We concluded that arthroscopic partial meniscectomy should be the preferred method for the surgical treatment for discoid lateral menisci, due to it's minimal traumatic effects, possibilities of early mobilization, a lower complication rate, and easy and short rehabilitation period.

Arthroscopy↗

PubMed2003

Polygonal triple (Kotz) osteotomy in the treatment of acetabular dysplasia: 17 patients (19 hips) with 4-9 years of follow-up.

We reviewed 19 hips in 17 patients between 17 and 33 years of age, who underwent a Kotz polygonal triple osteotomy. Their average follow-up was 7 (4.5-9) years. Although 13 patients had less pain after surgery, 3 continued to limp. The average corrections were 36 degrees for the center-edge angle, 31 degrees for the vertical center-edge angle and 19 degrees for Sharp's angle. 3 patients developed transient palsy of the sciatic nerve, and 3 asymptomatic nonunion of the ischium or pubic bone. The degree of arthrosis decreased in 10 hips.

Acetabulum↗

PubMed2003

Management of stiff hypertrophic nonunions by distraction osteogenesis: a report of 16 cases.

OBJECTIVE: Hypertrophic nonunions can be managed successfully with distraction. Hypertrophic changes indicate that the tissue at the nonunion site has a biologic healing potential. The missing component is an appropriate mechanical environment to transform a hypertrophic nonunion into solid bone. DESIGN: At our institution, the records of 10 male and 6 female patients treated for stiff hypertrophic nonunion with the Ilizarov distraction method were retrospectively analyzed. The average age of the patients was 42.3 years (range 15-69 years). The nonunion time ranged from 8-48 months. All patients had at least 1 cm shortening, 3 patients had a deformity in one plane, and 13 had a deformity in two planes. The pathology was localized to the upper extremity in 5 patients, to the lower extremity in 11 patients, with a periarticular localization in 11 patients. An Ilizarov-type circular external fixator was applied in all patients to correct shortening, to correct deformity, and to achieve a solid union. RESULTS: All nonunions healed at an average follow-up of 38.1 months (range 24-95 months). The average time spent in the external fixator was 7.1 months (range 5-10 months). The average preoperative length discrepancy was 2.25 cm (range 1-8 cm), which was eliminated in all patients at the time of frame removal. The average coronal plane angulation of 19.7 degrees (range 15-37 degrees) and sagittal plane angulation of 20.8 degrees (range 5-45 degrees), together with translation in one patient, also were corrected to normal anatomic alignment. Complications included minor pin tract infections and hardware problems; recurrence of deformity was observed in one patient who refused to wear a protective brace after frame removal. CONCLUSIONS: Hypertrophic nonunions can be managed successfully with distraction. The Ilizarov device can address every aspect of a stiff hypertrophic nonunion, including shortening and deformity.

Adolescent↗