Mehmet Colak

Mersin University, Mercin, Mersin, Turkey

Are you Mehmet Colak?

Claim your profile

Publications (15)29.42 Total impact

  • Article: Bacteriophage Therapy in Implant-Related Infections: An Experimental Study.
    [show abstract] [hide abstract]
    ABSTRACT: BACKGROUND: Implant-related infections with bacteria resistant to multiple antibiotics represent one of the major problems in orthopaedic surgery. It was our hypothesis that local application of bacteriophages, which are bacteria-destroying viruses, would be effective against biofilm-forming bacteria. METHODS: An implant-related infection model was created using methicillin-resistant Staphylococcus aureus (MRSA) in forty-eight rats and Pseudomonas aeruginosa in another forty-eight rats. Each group was divided into four subgroups; one subgroup received a bacterium-specific bacteriophage (Sb-1 in the MRSA group and PAT14 in the Pseudomonas aeruginosa group), one received antibiotic for fourteen days (20 mg/kg/day teicoplanin in the MRSA group, and 120 mg/kg/day imipenem + cilastatin and 25 mg/kg/day amikacin in the Pseudomonas group), one received antibiotic and bacteriophage, and one received no treatment. Animals receiving bacteriophage therapy were injected locally with 107 bacteriophages in a 0.1-mL suspension on three consecutive days. All animals were killed on the fifteenth day after initiation of treatment, and the tibia was excised. Results were assessed with use of microbiology, light microscopy, and electron microscopy. RESULTS: In the MRSA group, the antibiotic administration significantly decreased the number of colony-forming units per subject in quantitative cultures (control subgroup, 50,586; bacteriophage, 30,788; antibiotic, 17,165; antibiotic + bacteriophage, 5000; p = 0.004 for the comparison of the latter group with the control). Biofilm was absent only in the antibiotic + bacteriophage subgroup. In the Pseudomonas group, the number of colony-forming units per subject in quantitative cultures was significantly lower in each treatment subgroup compared with the control subgroup (control subgroup, 14,749; bacteriophage, 6484 [p = 0.016]; antibiotic, 2619 [p = 0.01]; antibiotic + bacteriophage, 1705 [p < 0.001]). The value in the antibiotic + bacteriophage subgroup was also significantly lower than the values in the other subgroups (p = 0.006). Biofilm thickness did not differ significantly among the subgroups in the Pseudomonas group. CONCLUSIONS: The addition of bacteriophage treatment to an appropriate antibiotic regimen helped to dissolve the biofilm of both types of bacteria studied. This effect on MRSA was more pronounced than that on Pseudomonas aeruginosa. CLINICAL RELEVANCE: The addition of bacteriophage therapy to a standard antibiotic regimen may represent a valuable adjunct for eradicating implant-related infections.
    The Journal of Bone and Joint Surgery 01/2013; 95(2):117-125. · 3.27 Impact Factor
  • Article: Clinical findings of vertebral osteomyelitis: Brucella spp. versus other etiologic agents.
    [show abstract] [hide abstract]
    ABSTRACT: We aimed to evaluate patients with vertebral osteomyelitis (VO) in our region and to compare the clinical and laboratory parameters of brucellar and non-brucellar VO patients (NBVO). This retrospective study included 80 patients with VO followed in our hospital between August 2004 and September 2010. The distribution of gender was 43 females (53.8%) and 37 males (46.2%) with average age of 52.5. Patients with brucellar vertebral VO (BVO; n = 30) accounted for 37.5% of all patients, and the rest (n = 50) were with NBVO. Co-morbidities existed in 32.5% of patients. In statistical comparison of VO patients who had the Brucella spp. as the infectious agent with patients of VO by non-brucellar pathogens, the following factors were found out to be significantly associated with BVO; low Charlson score (P = 0.0001), lower co-incidence with chronic renal failure (P = 0.001), high frequency of constitutional symptoms (P = 0.006), fever (P = 0.005), low-level inflammatory markers (WBC; Neutrophil; ESR; CRP, P values 0.006; 0.001; 0.022; 0.002, respectively), low-rate surgical treatment (P = 0.02) and culture positivity (P = 0.0001) and higher hemoglobin, total protein, albumin values (P = 0.002; 0.032; 0.016, respectively). VO may be strongly associated with brucellosis in patients presenting with fever and symptoms, low Charlson score and indistinct inflammatory markers.
    Rheumatology International 11/2011; · 1.88 Impact Factor
  • Article: Forty-five-degree or higher insertion angles are required to penetrate the opposite cortex in bicortical applications of Kirschner wires: an in vitro study on sheep bones.
    [show abstract] [hide abstract]
    ABSTRACT: Slippage of the wires over the opposite cortex from the endosteal side is frequent and can lead to insufficient stability. This in vitro biomechanical study was planned to investigate the angle of wire insertion that leads to trans cortex perforation. Long bones of sheep were cut longitudinally into two pieces and half bones were stabilised on a frame. Three orthopaedic surgeons performed the experiment using ten wires of four different diameters at two different drilling speeds. Each wire was introduced from the endosteal side at angles starting at 30° in 5° increments until perforation. When perforation was achieved, the angle was recorded. To determinate the critical angle of perforation, receiver operating characteristic (ROC) curve analyses was performed. Two-way factorial analysis of variance (ANOVA) and Kruskal-Wallis tests were used for statistical comparisons. Kirschner-wire insertion angles of ≥ 45° provided perforation with a percentage of 83.9 %. Wire diameter, drilling speed and surgeon variables had no effect on perforation angles (p > 0.05). If preoperative evaluation of fractures to be fixed by K wires reveals the need for oblique wire insertion angle < 45°, a standard trocar-tip K wire application would lead to slippage of the wire tip on the endosteal surface of the opposite cortex. According to this study, the operative plan should be changed if such obliquity of the K wire is mandatory during bicortical applications.
    International Orthopaedics 05/2011; 36(4):857-62. · 2.03 Impact Factor
  • Article: Anterior cruciate ligament reconstruction improves the metabolic energy cost of level walking at customary speeds.
    [show abstract] [hide abstract]
    ABSTRACT: The metabolic energy cost of walking is altered by pathological changes in gait. It is thought that anterior cruciate ligament (ACL) deficiency alters the energy requirement for level walking through its effect on gait pattern. In this study, it is hypothesised that the metabolic energy cost of walking would improve after ACL reconstruction. Eight patients who were undergoing ACL reconstruction for an isolated rupture were included in this prospective study. Clinical examinations, Lysholm scores and metabolic tests were performed preoperatively and at 3, 6 and 12 months after ACL reconstruction using autologous quadruple hamstring tendons. For the metabolic evaluation, net oxygen cost was calculated while walking on a treadmill at 50-, 70- and 90-m/min velocities. A two-way factorial ANOVA was performed in order to evaluate the primary effects and interactions of the time point and velocity variables on net oxygen cost. All patients had positive Lachman and anterior drawer tests preoperatively that became negative postoperatively and remained negative until the last follow-up point. The mean preoperative Lysholm score was 66, whereas the mean postoperative follow-up scores were 85, 91 and 94, respectively. The interaction between follow-up time point and velocity was not significant. Regardless of the selected velocity, the net oxygen cost was lower than that at preoperative levels at each postoperative time point (p < 0.05). The results of the present study indicate that the energy cost of level walking in chronic ACL-deficient patients improves after ACL reconstruction. Cause-effect-based studies with correlation evaluations that compare kinetic, kinematic and electromyographic data and metabolic cost calculations should facilitate more accurate analyses. Therapeutic study, Level 4.
    Knee Surgery Sports Traumatology Arthroscopy 02/2011; 19(8):1271-6. · 2.21 Impact Factor
  • Article: A new upper extremity sparing non-weight bearing orthosis.
    [show abstract] [hide abstract]
    ABSTRACT: Axillary and forearm crutches are commonly utilized in the treatment of foot and ankle injuries. In order to decrease the energy expenditure during mobilization, to prevent upper extremity complications, and to let the upper extremity free for other usages, we designed a new orthosis. The study is conducted to compare walking energy parameters of this newly designed orthosis with the axillary and forearm crutches. 10 healthy young male volunteers walked on treadmill with three different orthoses in randomized order. Oxygen expenditure, oxygen cost, rate of perceived exertion (Borg scale), and observer stability assessment were analyzed. Concerning oxygen consumption, perceived exertion, and observer stability assessment, the new device was found superior to the other devices (P<0.05). The new orthosis was superior to forearm crutches concerning oxygen cost (P=0.027) but not significantly different from the axillary crutches (P=0.062). Compared to frequently used orthoses, the developed device provides mobilization using less or similar amount of energy. Additionally it spares one upper extremity to be used for other activities.
    Gait & posture 10/2010; 32(4):661-3. · 2.58 Impact Factor
  • Source
    Article: Intrapelvic mass causing femoral compression neuropathy in a patient with Gaucher disease: a case report.
    [show abstract] [hide abstract]
    ABSTRACT: Gaucher disease is a lysosomal storage disorder in which glucocerebroside accumulates within the macrophages in any part of the body. Varying degrees of skeletal involvement may occur besides anemia, coagulation abnormalities and hepatosplenomegaly. Most of the factors influencing the quality of life in a patient with Gaucher disease are related to bone involvement. Gaucher cell deposits may extrude through cortical erosions and cause soft tissue masses around bones which are involved by the disease. We present a 38-year-old female patient with Gaucher disease who had a large intrapelvic mass originating from left iliac bone causing femoral compression neuropathy. The classification of disease is based on neurological involvement and if symptoms exist whether the symptoms are acute or subacute. The neurological impairment caused by compression by a tumor should be distinguished from the ones reported in neurogenic forms of the disease.
    Eklem hastalıkları ve cerrahisi = Joint diseases & related surgery. 01/2009; 20(3):169-73.
  • Article: Septic arthritis of the hip in relation with femoral neck fracture: a report of three cases.
    Orthopedics 02/2008; 31(1):83. · 2.66 Impact Factor
  • Source
    Article: [The effect of low-intensity pulsed sound waves delivered by the Exogen device on Staphylococcus aureus morphology and genetics].
    [show abstract] [hide abstract]
    ABSTRACT: We investigated the effect of low-intensity pulsed sound waves delivered by the Exogen device, which is recommended for the treatment of delayed union and nonunion in orthopedic surgery, on the colony number, antimicrobial susceptibility, bacterial morphology, and genetics of Staphylococcus aureus, which is a frequent pathogen in orthopedic infections. Thirty tubes containing 0.5 McFarland suspensions of S. aureus (ATCC 25923) were used. Fifteen tubes forming the test group were subjected to low-intensity sound waves by the Exogen device for 20 minutes. The remaining 15 tubes were untreated as controls. The two groups were then compared with respect to colony number, antibiotic susceptibility, and genotypic properties. The tubes were examined histologically by electron microscopy. The test tubes treated with sound waves showed a significantly lower number of bacteria colonies compared to the control tubes (p<0.001). The two groups were similar with respect to antibiotic susceptibility and genotypic properties. Bacterial cell wall structure in the control group was of normal appearance, whereas partial destruction and break-up were observed in test samples. Bacterial cell wall thickness was significantly higher in the test group compared to the control group (41.54 nm and 24.27 nm, respectively; p<0.001). Low-intensity sound waves may be beneficial as a prophylactic measure to prevent infections in primary orthopedic operations and as an adjuvant therapy for infected nonunions.
    acta orthopaedica et traumatologica turcica 02/2008; 42(4):272-7. · 0.34 Impact Factor
  • Article: Histoacryl glue in meniscal repairs (a biomechanical study).
    [show abstract] [hide abstract]
    ABSTRACT: The purpose of this study was to investigate the biomechanical efficacy of Histoacryl (cyanoacrylate, N-asetil 2 butyl sistein) in meniscal tear repair. In our study, the primary stability of three different repair techniques in delaying the formation of a gap of 2 mm was investigated. A meniscal tear was repaired with two vertical sutures and Histoacryl in the first group; it was repaired only with Histoacryl in the second group, and with only two vertical sutures in the third group. Menisci were then placed in a tensile loading machine, and the primary stability of the repair zones was measured until a displacement of 2 mm occurred. Biomechanical force was significantly (P<0.05) high (112.0+/-17.20 N) in all groups when vertical suture and Histoacryl glue were used together during displacements of 0.5, 1.0, 1.5 and 2.0 mm. We believe that Histoacryl is superior to vertical sutures regarding gap delaying. It potentiates the effect of vertical suture strength, permits early motion and thus merits an in vivo study.
    International Orthopaedics 04/2007; 31(2):241-6. · 2.03 Impact Factor
  • Article: The effect of pentoxifylline in treatment of skin degloving injuries: an experimental study.
    [show abstract] [hide abstract]
    ABSTRACT: Management of skin degloving injuries is still a problematic issue and the avulsed part of the skin may become necrotic. In this pilot study, we attempted to develop an experimental model for degloving injuries and investigated the efficacy of pentoxifylline, a well-known potent agent in enhancement of erythrocyte flexibility and tissue vascularization, in treatment of this injury model. Degloving injuries were created in 15 rats' tails by circular puncturing of the skin at the middle of the tail and then applying moderate force to avulse the skin from the underlying tissue. Then, the skin was repaired back to its original position. No treatment was given in the first group (n=6). In the second group (n=3), 0.4cm(3) physiological serum was administered intraperitoneally for 10 days. In the third group (n=6), intraperitoneal 25mg/kg pentoxifylline was administered for 10 days. Tails were observed daily for 21 days and then examined histopathologically. At the end of the study, the avulsed segment of the skin became cyanotic and ulcerated in the first and the second group, and in the third group, the skin was intact. In histopathological examination, loss of superficial ephitelium and dense infiltration of inflammatory cells were seen in groups 1 and 2, and the skin layers were normal in the group 3. Pentoxifylline improved tissue preservation and was proved to be highly beneficial in treatment of skin degloving injuries.
    Injury 08/2006; 37(7):638-41. · 1.98 Impact Factor
  • Article: Early internal fracture fixation prevents bacterial translocation.
    [show abstract] [hide abstract]
    ABSTRACT: The aim of our study was to determine whether early internal fixation of major bone fractures helps prevent bacterial translocation in patients with multitrauma. Thirty-seven Sprague-Dawley rats were divided into three groups: (1) anesthesia only (n = 12); (2) the trauma group: tibia and femur fractures and moderate head trauma under anesthesia (n = 14); and (3) the fixation group: fixation of tibia and femur fractures and moderate head trauma under anesthesia (n = 11). After 24 hours, mesenteric lymph nodes, liver, spleen, and systemic blood samples were quantitatively cultured. The terminal ileum was assessed histopathologically. The incidence of bacterial translocation was less in the anesthesia group (two of 12 rats) and the fixation group (two of 11 rats) than in the trauma group (10 of 14 rats). The number of organs containing viable bacteria was significantly lower in the fixation group than in the trauma group. Histopathologically, villous architecture was preserved mostly in the fixation group; however, marked mucosal damage was detected in the trauma group. Our data suggest early internal fixation of long bone fractures in polytraumatized experimental animals with head injury results in preservation of the intestinal mucosal barrier and decreased bacterial translocation from the gut.
    Clinical Orthopaedics and Related Research 06/2006; 446:253-8. · 2.53 Impact Factor
  • Article: Traumatic musculocutaneous neuropathy: a case report.
    [show abstract] [hide abstract]
    ABSTRACT: Isolated injury of the musculocutaneous nerve is a rare disorder. Reported cases are claimed to present with loss of biceps and brachialis power without a disturbing pain. The injury generally occurs after strenuous exercise and could be demonstrated by electrophysiological examination. We report a case of musculocutaneous nerve injury which occurred after a vigorous push and which presented with unusual symptoms and findings. The patient complained of episodic severe pain attacks which started from the axilla and radiated over the musculocutaneous nerve distribution including the lateral antebrachial cutaneous nerve area. He did not respond to 3 months of conservative treatment including multiple corticosteroid injections and finally required surgical release. Surgical epineurotomy resulted in immediate relief. This is the first reported case of acute musculocutaneous nerve injury presenting with unusual symptoms and findings. The operative release procedure performed was also not required in any of the other reported cases. An excellent result was obtained with epineurotomy.
    Archives of Orthopaedic and Trauma Surgery 08/2005; 125(6):414-6. · 1.37 Impact Factor
  • Article: Effect of patient age and symptom duration on subjective and objective outcomes of carpal tunnel surgery.
    [show abstract] [hide abstract]
    ABSTRACT: This study prospectively examined the relationship between patient age and symptom duration on surgical outcome of carpal tunnel syndrome. Surgical outcomes were evaluated using both subjective and objective measures and statistical analysis was performed using canonical analysis. The result revealed patient age and symptom duration have significant effects on bot subjective and objective outcomes of carpal tunnel surgery.
    Orthopedics 07/2005; 28(6):600-2. · 2.66 Impact Factor
  • Article: Injection-induced contracture of the quadriceps femoris muscle in children.
    Orthopedics 02/2004; 27(1):65-6. · 2.66 Impact Factor
  • Article: Nerve entrapment in painful heel syndrome.
    [show abstract] [hide abstract]
    ABSTRACT: Subcalcaneal heel pain is one of the most common foot ailments, yet the exact etiology is still controversial. Nerve entrapment has been suggested as one of the possible causes of this painful condition in recalcitrant cases. The purpose of this study is to determine the role of nerve entrapment in painful heels. Twenty patients with heel pain (25 heels) were compared with an age and body mass index-matched control population using electrodiagnostic methods. The results of the study revealed 22 heels (88%) with heel pain had lateral plantar nerve entrapment signs with or without medial plantar nerve findings on EMG. There were no abnormal values in the control group. Nerve entrapment syndrome has previously been considered only in cases with intractable heel pain, but this study suggests that it may play a role the early phases of painful heel syndrome.
    The Foot and Ankle Online Journal 04/2002; 23(3):208-11. · 1.22 Impact Factor