Biomedical subjects

Mahmut Nedim Doral

Publications and source records attributed to Mahmut Nedim Doral.

At least 19 recordsLinked to original sources

PubMed2006

Pullout strength of meniscal repair after cyclic loading: comparison of vertical, horizontal, and oblique suture techniques.

This in vitro biomechanical study with cyclic loading compared the pullout strength of vertical, horizontal, and oblique sutures used for meniscal lesion repair. Following repair of vertical longitudinal lesions created in bovine medial menisci, three groups of seven specimens (vertical, horizontal, and oblique sutures) underwent cyclic loading in a randomized test order (5 mm/min, cycling between 5 and 50 N at 1 Hz for 100 cycles) prior to load to failure testing (5 mm/min). Displacement did not differ between groups during cyclic or load to failure testing. Construct stiffness during cyclic testing was superior for the oblique suture (6.9 +/- 1.5 N/mm, P = 0.007) and the vertical suture (6.4 +/- 7 N/mm, P = 0.03) groups compared to the horizontal suture group (4.4 +/- 0.52 N/mm). The oblique suture (171.9 +/- 25.9 N, P < 0.0001) and the vertical suture (145.9 +/- 32.3 N, P = 0.001) groups displayed superior load at failure compared to the horizontal suture group (88.8 +/- 8.2 N). Construct stiffness during load to failure testing did not differ between groups. Suture rupture was the failure mode for all specimens of the oblique suture group. Suture rupture was the failure mode for 57% (4/7) of the vertical suture group with the remaining specimens (3/7, 43%) failing from intact suture pullout through meniscal tissue. All horizontal suture group specimens failed by intact suture pulling through meniscal tissue. With comparable stiffness during cyclic testing, comparable load at failure as vertical sutures, and less evidence of intact suture pullout through the meniscus, an oblique suture technique may combine the beneficial characteristics of vertical (superior biomechanical strength) and horizontal (ease of application, longer sutures with a tendency to cover a larger meniscal tissue area) suture-repair techniques.

Animals↗

PubMed2006

Three-bundle popliteus tendon: a nonsymptomatic anatomical variation.

A 34-year-old man suffering from knee pain on the medial side of his right knee underwent knee arthroscopy. The arthroscopy revealed the popliteus tendon with an appearance of three bundles. Three-bundle popliteus tendon is a normal variant finding with no clinical significance.

Adult↗

PubMed2006

A complete supra-patellar plica with an unusual presentation.

A suprapatellar plica is a persistent remnant of the embryologic synovial membrane between the suprapatellar pouch and the knee joint. Pathologic synovial plica is not a common entity, however, when present, it can mimic a variety of clinical situations. We describe here a case of pathologic suprapatellar plica that has a check-valve mechanism, which results in a clinical presentation as knee joint swelling.

Adult↗

PubMed2006

Anatomic factors and biomechanics in ankle instability.

Ankle sprains are common in both sport and leisure activities. Despite the high success rates of conservative management, approximately 10% to 30% patients develop chronic instability. Surgery yields high success rates, but clinical problems such as functional and mechanical instability, persistent talar tilt, range of motions limitations, and pain may persist despite surgery.

Ankle Joint↗

PubMed2005

Decrease in the numbers of mechanoreceptors in rabbit ACL: the effects of ageing.

It is proposed that there is a positive correlation between the numbers of mechanoreceptors and proprioceptive function. On the other hand, normal aging process is associated with deficits in proprioception. This study is designed to test the hypothesis that aging resulted in decreased numbers of mechanoreceptors. Anterior cruciate ligaments of 14 male rabbits (2 months, n=5; 12 months, n=4 and 60 months, n=5) were extracted and the total numbers of Ruffini, Pacini and Golgi tendon-like receptors were accounted. As a result, the numbers of mechanoreceptors, especially Ruffini receptors, decreased with aging (p<0.05). Increased age was associated with changes in the morphology of mechanoreceptors. In conclusion, aging results in both diminished numbers and changed morphology of mechanoreceptors.

Aging↗

PubMed2005

The effects of menstrual cycle on the knee joint position sense: preliminary study.

The purpose of this study was to determine the effects of menstrual cycle on proprioception by using the active knee joint position sense test (JPST). The 19 healthy women (ages between 20 years and 27 years) who have normal regular menstrual cycle were included in the study. We applied JPSTs at two different directions throughout the three different phases of the menstrual cycle, i.e. menstrual, follicular, and early luteal in dominant knees. When we started from flexion (90 degrees ), target angles were 70 degrees , 50 degrees , and 30 degrees and we started from extension (0 degrees ), target angles were 20 degrees , 40 degrees and 60 degrees . The absolute reposition errors from the target angles have been evaluated. Results have shown that reposition errors from the target angle at 40 degrees , 50 degrees and 70 degrees of knee angles were higher in the menstrual phase than that of the follicular phase (P<0.05). In addition, higher value of reposition error from the target angle at 40 degrees was found in the menstrual phase compared to luteal phase (P<0.05). In conclusion, we have demonstrated that active JPST was significantly reduced in the menstruation period.

Adult↗

PubMed2005

Analgesic effect of intra-articular tramadol compared with morphine after arthroscopic knee surgery.

PURPOSE: The aim of the study was to compare the analgesic effect of 5 mg intra-articular (IA) morphine with 50 mg IA tramadol. TYPE OF STUDY: Prospective double-blind randomized trial. METHODS: Seventy-five patients having elective arthroscopic surgery of the knee were randomized to receive IA tramadol 50 mg (tramadol group), IA morphine 5 mg (morphine group), or IA normal saline (control group), in equivalent volumes (20 mL). The tourniquet was released 10 minutes after analgesic administration. Verbal pain rating score between 0 and 10 (VRS), supplemental analgesic requirements, and incidence of side effects were recorded postoperatively. RESULTS: Results are given as (median [5-95 percentiles]). The control group had a significantly shorter time to first analgesic request (25 min [15-55]) than morphine group, (34 min [15-158], P < .008) and the tramadol group, (33 min [17-728], P < .008). The patients in the control group complained of more severe pain (VRS 7 [4-10]) when they arrived at the postanesthesia care unit compared with the morphine group (VRS 1 [0-9], P = .002) and with the tramadol group (VRS 0 [0-9], P = .002). These treatment benefits were especially prominent in the patients who had meniscectomy or in the subgroup of patients with more than 6 months of preoperative pain. There was no statistical difference between the tramadol and morphine groups in the time to first analgesia, postoperative pain scores after arrival at the postanesthesia care unit, consumption of rescue analgesic, or side effects. CONCLUSIONS: We conclude that 50 mg IA tramadol provides analgesia equivalent to 5 mg IA morphine. LEVEL OF EVIDENCE: Level II, randomized controlled trial that shows no significant difference and lacks narrow confidence intervals.

Adult↗

PubMed2005

Ketamine sedation during spinal anesthesia for arthroscopic knee surgery reduced the ischemia-reperfusion injury markers.

We studied the effect of ketamine sedation on oxidative stress during arthroscopic knee surgery with tourniquet application by determining blood and tissue malonyldialdehyde (MDA) and hypoxanthine (HPX) levels. Thirty ASA I-II patients undergoing arthroscopic knee surgery with tourniquet were randomly divided into two groups. Spinal anesthesia induced with 12.5 mg bupivacaine was administered to all patients. In the ketamine group, after IV administration of 0.01 mg/kg midazolam, a continuous infusion of ketamine (0.5 mg . kg(-1) . h(-1)) was used until the end of surgery whereas the placebo group received a volume-equivalent placebo infusion. Ramsey Sedation Scale (RSS) was used for assessing the sedation level. Venous blood and synovial membrane tissue samples were obtained before ketamine infusion, at 30 min of tourniquet ischemia, and at 5 min after tourniquet deflation for MDA and HPX measurements. Tissue MDA and HPX levels were significantly less in the ketamine group than the control group after reperfusion. RSS scores were higher in the ketamine group without any adverse effect. We conclude that ketamine sedation attenuates lipid peroxidation markers in arthroscopic knee surgery with tourniquet application.

Adult↗

PubMed2005

[The effect of the tibial tunnel fixation level on the results of cyclic loading in anterior cruciate ligament reconstruction].

OBJECTIVES: This study was designed to compare the biomechanical characteristics of non-anatomic (far from joint) and anatomic (close to joint) levels of tibial tunnel fixation with soft tissue graft using a soft tissue interference screw in anterior cruciate ligament (ACL) reconstruction. METHODS: Twelve bovine tibiae and digital extensor tendons were divided into two homogeneously equal groups after removing soft tissues. Tibial tunnels were prepared with a 7-mm drill with the use of an ACL guide adjusted to 45 degrees . Each tunnel was then dilated to 9 mm in 0.5 mm increments. Digital extensor tendons were fixed at non-anatomic (group I) or anatomic (group II) tibial tunnel levels with a soft tissue metal interference screw, 9 x 30 mm in size. All the specimens were cycled 500 times from 50 to 250 N with 1 Hz frequency in a servo-hydraulic testing machine followed by ultimate load at-failure testing at a rate of 20 mm/min. Statistical analyses were made using the Mann-Whitney U-test. RESULTS: The mean screw insertion torque values were 8.2+/-2.4 Nm and 7.8+/-2.3 Nm in groups I and II, respectively (p=0.88). The mean values of graft displacement (1.9+/-0.75 mm versus 2.2+/-1.2 mm, p=0.63) and stiffness (132.72+/-10.93 N/mm versus 125.14+/-15.93 N/mm, p=0.63) did not differ significantly. CONCLUSION: The biomechanical properties of ACL reconstruction with soft tissue graft fixation using a soft tissue interference screw are not influenced by the level of tibial tunnel fixation.

Absorbable Implants↗

PubMed2005

[The effect of anterior or posterior tibial tunnel placement of a soft tissue graft with a soft tissue interference screw on fixation biomechanics].

OBJECTIVES: We investigated the biomechanical characteristics of anterior or posterior tibial tunnel placement of the soft tissue graft with a soft tissue interference screw in anterior cruciate ligament (ACL) reconstruction. METHODS: Twelve bovine tibiae and digital extensor tendons were divided into two homogeneously equal groups after they were stripped of all soft tissues. Tibial tunnels were prepared and digital extensor tendons were fixed at nonanatomic (apart from the joint) anterior (n=6, group I) or posterior (n=6, group II) tibial tunnel positions with a soft tissue metal interference screw, 9x30 mm in size. All the specimens were cycled 500 times from 50 to 250 N at 1 Hz frequency in a servo hydraulic test device, after which ultimate load-at-failure testing was performed at a rate of 20 mm/min. RESULTS: The mean screw insertion torque values were 8.2+/-2.4 Nm and 8.4+/-2.8 Nm in groups I and II, respectively (p=0.88). No significant differences were found between the two groups with respect to graft displacement (1.9+/-0.8 mm vs 2.3+/-0.4 mm; p=0.38) and stiffness (132.7+/-10.9 N/mm vs 126.4+/-8.5 N/mm, p=0.98) at the end of cyclic loading. CONCLUSION: Our results show that the site of nonanatomic soft tissue graft fixation in the tibial tunnel (anterior or posterior) with a soft tissue interference screw do not affect the biomechanical parameters in ACL reconstruction.

Animals↗

PubMed2004

The impact of proximal fibula fractures in the prognosis of tibial plateau fractures: a novel classification.

Fifty-five patients who presented with the complaint of tibia plateau fractures between January 1998 and November 2001 were retrospectively evaluated. The evaluation was based on their treatment modality. Twenty-five conservatively-treated patients (group 1) and 30 surgically-treated patients (group 2) were evaluated. In group 1, seven patients with proximal fibula fractures had lateral hamstring tightness. Five out of these seven patients had concomitant lateral knee pain. Similarly, nine patients with proximal fibula fractures in group 2 had lateral hamstring tightness, and seven patients in the same group suffered from lateral knee pain. The patients with no fibula proximal fracture in both groups had no hamstring tightness or lateral knee pain. The proximal fibula in the knee joint and its anatomical structures are of utmost importance for the anatomical integrity of the knee and its normal functions. The fibula has rich anatomical relations, some of which are important structures of the knee. These anatomical structures and the fibula provide stability of the knee joint and its functions as well as being an important mechanical support to the knee joint. Therefore, the knee joint will receive the negative effects from the pathologies of the bone or soft tissue that may occur in fibula fractures.

Adolescent↗

PubMed2004

Reliability of isokinetic ankle inversion- and eversion-strength measurement in neutral foot position, using the Biodex dynamometer.

This study was designed to investigate the intratester and intertester reliability of isokinetic ankle inversion and eversion-strength measurement in neutral foot position in healthy adults using the Biodex dynamometer. Twenty-five men and women performed five maximal concentric contractions at 60 and 180 degrees/s angular velocities. Two physicians tested each subject. The first physician applied the test four times, and the second physician three times. Reliability of peak torque was assessed by calculating the intraclass correlation coefficient (ICC). At both angular velocities, inversion strength was greater than eversion, and when the angular velocity was increased, inversion and eversion strength were decreased, as tested by both physicians. The first measurements of inversion and eversion strength of the first physician were significantly lower than the other measurements (p<0.01). The intratester ICCs for ankle inversion in healthy young adults were highly reliable (ICC 0.92-0.96), and for the eversion values ranged from 0.87 to 0.94. Intertester ICCs for ankle inversion and eversion peak torque values demonstrated a value of 0.95. Isokinetic tests of ankle inversion and eversion strength at 60 and 180 degrees/s angular velocities in neutral foot position for healthy adults are highly reliable with the Biodex dynamometer.

Adult↗

PubMed2004

Influence of irrigation solutions combined with colchicine and diclofenac sodium on articular cartilage in a rat model.

A two stage, controlled animal trial was designed to observe the effects on normal and manually damaged articular cartilage of the rat knee joint of colchicine (COL) and diclofenac sodium (DIC) added into washout solutions. In the first stage, 21 rats were randomized into three groups, and right knees of all groups were washed-out by either COL, DIC or physiologic saline (PS) solutions. The left side was kept as a paired control. After 18 months, all knees were evaluated macroscopically and microscopically for cartilage changes. In the second stage, 25 rats were randomized into four groups, and a 2 x 2 mm defect was created surgically on the medial condyle. The joints were washed out by either COL, DIC or PS solutions. At the end of the six months, macroscopic, microscopic and transmission electron microscopy (TEM) evaluations were performed to observe the changes to the defective area. The results showed that washout procedures with certain arthroscopic fluid modifications revealed macroscopically less fibrillation and surface changes for the COL and DIC groups in the first stage. Colchicine and diclofenac sodium solutions conducted a better effect on the thickness of the cartilage and gave better results according to Mankin's criteria for degeneration. In the second stage, COL and DIC groups showed better effects on the cartilage regeneration. The pharmacological agents added into the arthroscopic washout fluid may have an effect on the ultrastructure and biologic properties of the joint cartilage, and may improve the results of arthroscopic treatment in chondral pathologies, especially in secondary arthritis.

Administration, Topical↗

PubMed2004

The efficacy of intra-articular ketamine for postoperative analgesia in outpatient arthroscopic surgery.

PURPOSE: The purpose of this study was to compare the postoperative analgesic effects of intra-articularly administered ketamine, neostigmine, and bupivacaine after outpatient arthroscopic surgery. TYPE OF STUDY: Prospective, randomized, double-blind, clinical study. METHODS: In this study, 60 patients undergoing arthroscopic surgery other than ligament reconstruction were evaluated for postoperative pain. Ketamine, neostigmine, and bupivacaine were administered intra-articularly. The period of effective analgesia, recorded in minutes, was measured between time 0 and first usage of patient-controlled anesthesia (PCA) by the patients. The visual analog scale (VAS) was used to describe the pain level of the patient. RESULTS: VAS values were lower for the 3 medication groups compared with the placebo at rest and 90 degrees knee flexion. Intra-articular administration of 0.5 mg/kg ketamine provided longer duration of analgesia as defined by the first PCA use time (P <.05). The total amount of pethidine and analgesia time were longer for the 3 medication groups. CONCLUSIONS: Our basic finding was reduction in postoperative pain and consumption of adequate analgesic drugs with intra-articular ketamine, bupivacaine, or neostigmine use. We have not seen any psychomimetic side effects, particularly as seen with higher doses or systemic use. This study may conclude that intra-articular administration of ketamine provides long-lasting and effective analgesia, similar to neostigmine but less effective than bupivacaine after knee arthroscopy without any adverse effects. LEVEL OF EVEIDENCE: Level I.

Adolescent↗

PubMed2004

Vascular malformation in the infrapatellar (Hoffa's) fat pad.

A 16-year-old girl presented with pain and swelling of her right knee for 2 years. Magnetic resonance imaging disclosed a mass in the infrapatellar fat pad. Arthroscopic removal of the lesion led to a histopathologic diagnosis of vascular malformation, which has not been reported exclusively in this location.

Adipose Tissue↗

PubMed2004

Cervical and lumbar spinal changes diagnosed in four-view radiographs of 732 military pilots.

BACKGROUND: Pilots who fly jet fighters or helicopters frequently experience vertebral problems due to acceleration and vibration, wearing helmets and other headgear, and sitting in suboptimal postures. METHODS: We looked for spondylarthritic or spondylitic changes in 4-view radiographs (AP, lateral, left and right oblique) of the cervical and lumbar vertebrae of 732 pilots and 202 non-flying controls. The subjects included 91 F-16 jet pilots, 363 other jet pilots, 119 transport pilots, and 159 helicopter pilots. RESULTS: The prevalence of cervical changes in helicopter pilots was 19%, significantly higher than those for other pilots (8-13%) or controls (10%). There was no difference among groups with respect to prevalence of lumbar changes. Among all pilots, compression fractures were more common in the lumbar region than in the cervical region. Age was the most important variable related to spondylarthritic or spondylitic changes in all subjects, whereas height was an important factor only among jet pilots. CONCLUSION: We found an increased prevalence of cervical changes, especially osteoarthritis, in helicopter pilots. Increasing age and tall stature were associated with an increased prevalence of vertebral spondylarthritic or spondylitic changes in jet pilots.

Adult↗

PubMed2004

[Wrist injuries in children and adolescent athletes: macrotrauma and overuse].

Young children and adolescents are becoming increasingly involved in recreational and professional sports. This inevitably leads to an increase in the number of sports-related injuries involving the hand and the wrist. Hence, physicians should have a good insight into macro- and microtraumas affecting the hand and the wrist. Prevention of injuries, correction of muscle-tendon imbalances, and maintenance of strength and flexibility are important issues for the prevention of disabilities in this age group.

Adolescent↗

PubMed2004

[Patellar instability: arthroscopic surgery, indications and techniques].

A significant incidence of knee pain and disability arises from patellofemoral disorders. An accurate diagnosis relies both on a comprehensive history and a careful physical examination; radiologic modalities also play an important part in the diagnosis and follow-up. Most patellofemoral disorders can be examined in three groups: pain due to soft tissue abnormalities, patellar instability, and patellofemoral osteoarthritis. Conservative therapy can be successful in many patellofemoral disorders. Surgical treatment consists of lateral release, medial plication and reconstruction of the medial patellofemoral ligament, proximal and distal realignments, patellar osteotomies, and patellectomy. In traumatic dislocations primary reconstruction or arthroscopy assisted medial stabilization can be performed.

Arthroscopy↗