Murat Asci

A biomechanical comparison of polymethylmethacrylate-reinforced and expansive pedicle screws in pedicle-screw revisions

OBJECTIVES Different techniques and choices exist for revision of pedicle screws, two of which are pedicle screw combined with cement augmentation and expansive pedicle screw fixation. This biomechanical study was designed to compare the pullout strengths of two different revision techniques. METHODS Fourteen lumbar vertebrae obtained from four calves (mean age 15 months) were divided into two groups equal in number. Monoaxial 6.0-mm pedicle screws were inserted into the right pedicles, and axial pullout testing was performed at a rate of 10 mm/min and failure strengths were recorded. Revision was performed with the same-sized pedicle screws reinforced with polymethylmethacrylate in group 1, and with 7.0-mm expansive pedicle screws in group 2, and pullout testing was repeated to record maximum revision pullout strengths. RESULTS The mean pullout strengths recorded before and after revision were significantly different in both groups, being 2,162.9+/-718.5 N and 2,794.3+/-979.2 N in group 1 (p=0.041) and 2,605.0+/-487.6 N and 3,327.1+/-640.8 N in group 2 (p=0.012), respectively. However, the mean pullout strengths recorded before and after revision did not differ significantly between the two groups (p>0.05). CONCLUSION Our results showed that expansive pedicle screws 1 mm larger in diameter provide similar pullout strengths to those of same-sized, polymethylmethacrylate-reinforced screws in revision of pedicle screw fixation, suggesting that they can be preferred with the additional advantages of ease of application and avoiding risks for pedicle fracture and cement leakage.

Simvastatin improves spinal fusion in rats

OBJECTIVE Statins stimulate bone formation by inducing the expression of bone morphogenetic proteins (BMP-2). The aim of our study was to investigate the effects of orally administered simvastatin on spinal fusion in rats. METHODS Twenty rats were randomized into a spinal fusion group (SF) (n=10) or a spinal fusion and oral simvastatin administered group (SFS) (n=10). A spinal fusion was performed between L4-L6 representing two levels. Simvastatin (120 mg/kg/day) was administered orally in the SFS group. The rats were killed at the end of the 12 week study period. RESULTS Manual palpation revealed two moderate fusions in the SF group. The SFS group did not reveal any signs of pseudoarthrosis. An average three-point bending force causing failure of fusion revealed results of 148.80±39.403 Newtons and 123.80±28.479 Newtons in SFS and SF groups, respectively (p>0.05). Histological examination revealed better fusion grades in the SFS group (mean: 9.30±0.949) than in the SF group (mean: 6.80±2.044) (p=0.003). Radiographic examination revealed Grade C fusion in two levels and Grade A fusion in 18 levels in the SF group. In the SFS group, Grade C fusion was detected in one level and Grade A fusions in 19. CONCLUSION Our results suggest that simvastatin can promote spinal fusion and can be used as an adjunct to spinal fusion procedures in an elderly population with high cholesterol levels.

Evaluation of mobile bearing unicompartmental knee arthroplasty, opening wedge, and dome-type high tibial osteotomies for knee arthritis.

OBJECTIVE Three methods of surgery used in the treatment of knee osteoarthritis (OA) are mobile bearing unicompartmental knee arthroplasty (Oxford UKA), opening wedge high tibial osteotomy (HTO), and dome-type HTO. This article aimed to retrospectively compare these three methods in terms of outcomes for health status, patient satisfaction, and function. METHODS Between 2003 and 2010, 255 knees of 235 patients underwent operations for medial knee OA. Three types of surgery were performed. Group 1 consisted of 109 knees of 94 patients who underwent Oxford UKA. Group 2 was made up of 36 knees of 36 patients who underwent HTO using circular external fixation, and Group 3 comprised 57 knees of 52 patients on whom opening wedge type HTO using locking plate fixation was performed. SF-36 and HSS knee scores were used to compare the functional outcomes among groups. RESULTS Statistically significant differences were found between the preoperative and postoperative measures in all 3 of the treatment groups for physical function, physical role, pain, general health, vitality, social function, emotional role, and mental health according to SF-36 and HSS scores. In the 2nd group, the average correction of the mechanical axis deviation (MAD) was 38 mm with 11.7º along the femorotibial axis and 6.2º along the medial proximal tibial angle (MPTA). In the 3rd group, the average correction in the MAD was 28 mm with 9.7º along the femorotibial axis and 5.6º along the MPTA. All 3 of the treatment alternatives were observed to be sufficient. Satisfactory postoperative results were achieved in the UKA group in terms of social function and mental health, and the patients were able to achieve early rehabilitation and return to their previous life activities. CONCLUSION UKA is the ideal option for patients who wish for the earliest possible return to social and recreational activities.

Intraarticular Hyaluronic Acid Injection after Microfracture Technique for the Management of Full-Thickness Cartilage Defects Does Not Improve the Quality of Repair Tissue

Objective: Tissue repair that occurs after microfracture does not include hyaline-like cartilage. Therefore, other treatment modalities must be combined with microfracture to improve repair tissue quality. In this study, we combined exogenous hyaluronic acid with microfracture. Design: Thirty mature New Zealand rabbits were randomly divided into 3 groups as control, microfracture (MF), and microfracture and hyaluronic acid (MFHA). Four-millimetre full-thickness cartilage defects were created in the medial femoral condyle of each rabbit. Microfracture was performed on defects in the MF and MFHA groups. At 1 week following surgery, 1 mL of saline was injected into the knees of the control and MF groups, whereas 1 mL (15 mg/mL) hyaluronic acid was injected into the knees of the MFHA group 3 times weekly. At 6 months postsurgery, defects were evaluated according to the ICRS (International Cartilage Repair Society) and Wakitani scales. Results: According to the ICRS and Wakitani scales, the quality of repair tissue was improved in MF and MFHA groups as compared the control group (P = 0.001 and 0.001, respectively). No significant difference was observed between the MF and MFHA groups (P = 0.342). Conclusions: According to the model in this study, no beneficial effect was obtained when HA injection was combined with microfracture in the treatment of full-thickness cartilage defects.

Concurrent AC joint dislocation, coracoclavicular ligament rupture and coracoid base fracture

On plain radiographs, type 3 AC joint dislocation, fracture at the base of the coracoid extending to glenoid and multiple rib fractures on the right side was detected. Also, it was observed that CC distance was increased (Fig. 1). A computed tomography scan was obtained which revealed the displacement of the fracture that creates significant incongruity on the glenoid articular surface. Five days after the trauma, operation was performed in the beach chair position. Also, in order to harvest a tendon autograft, ipsilateral lower extremity was prepared and covered. A deltopectoral incision was used, and the glenohumeral joint was exposed through the rotator interval. Tear of the CC ligaments from their insertion site on the clavicle and the tear of the supraspinatus tendon attributed to trauma were observed. Fracture at the base of the coracoid was reduced and fixed by using two 4.5 mm cannulated screws. As it was not possible to reduce the AC joint, distal end of the clavicle was resected. Then, two 5 mm vertical tunnels were created in the clavicle by using a cannulated reamer. Semitendinosus tendon autograft harvested from the ipsilateral lower extremity was passed under the coracoid process. The limbs of the graft were crossed before being passed from the clavicular tunnels. The medial limb of the graft shuttled behind the clavicle and under the coracoid (Fig. 2). Then, two limbs of the graft were sutured to each other on the anterior surface of the clavicle. A number 5 Fiberwire (Arthrex Company, Naples, FL, USA) was used to reinforce the reconstruction by passing it around the clavicle and under the coracoid. Tear in the supraspinatus tendon was repaired by using two 5 mm anchors. The patient was followed with a sling in the post-operative period. After 3 weeks, rehabilitation was started by initiating shoulder movements. Full range of motion was obtained at the sixth week, and patient started to job at second month. Three years after the operation, he was Introduction

The effects of melatonin and caffeic acid phenethyl ester (CAPE) on fracture healing under ischemic conditions

OBJECTIVE The aim of this study was to investigate the effects of antioxidant molecules melatonin and caffeic acid phenethyl ester (CAPE) on fracture healing under ischemic conditions. METHODS A right tibia fracture was created and fixed with an intramedullary pin in forty four male Wistar-albino rats. The rats were then randomly allocated to fracture, fracture-ischemia, fracture- ischemia-melatonin, and fracture-ischemia-CAPE groups. Ischemia was created by clamping femoral arteries four and a half hours. Animals were killed and radiographic, histological and biomechanical evaluation was performed sixth week after surgery. RESULTS The radiological and histological scores of the fracture-ischemia-CAPE group were significantly better than the fracture- ischemia group at 6th week follow-up. Complete radiographical and histological healing of all fractures was detected in all groups. There was a significant difference between the maximum fracture force between the groups (fracture-ischemia<fracture-ischemia-melatonin<fracture<fracture-ischemia-CAPE) (p<0.005). Although difference was not statistically significant between fracture and fracture-ischemia-CAPE groups, all other groups revealed statistically significant difference with respect to toughness (N/mm). Fracture-ischemia group revealed the lowest toughness. CONCLUSION Ischemia adversely affects the fracture healing of rat tibias. Melatonin and CAPE eradicate adverse effects of ischemia. Possible adverse effects of ischemia on fracture healing can be eradicated with melatonin and CAPE in patients with tibia fractures associated with vascular injury or compartment syndrome.

Ipsilateral distal femoral and proximal tibial epiphyseal growth plate injury: a case report

IntroductionBoth the isolated distal femoral epiphysiolysis and the isolated proximal tibial epiphysiolysis are the least common epiphyseal injuries. Even though they are uncommon, they have a high incidence rate of complications.Case presentationWe present a case with Gustilo-Anderson grade 3b open and Salter-Harris type 1 epiphysiolysis of the distal femur and proximal tibia caused by a farm machinery accident. The patient was a 10-year-old boy, treated by open reduction and internal fixation.ConclusionAlthough distal femoral and proximal tibial growth plate injuries are rarely seen benign fractures, their management requires meticulous care. Anatomic reduction is important, especially to minimize the risk of growth arrest and the development of degenerative arthritis. However, there is a high incidence of growth arrest and neurovascular injury with these type of fractures.

Comparison of Ultrasound-Guided Supraclavicular and Interscalene Brachial Plexus Blocks in Postoperative Pain Management After Arthroscopic Shoulder Surgery

The interscalene brachial plexus block (ISBB) is an effective procedure for minimizing postoperative opioid consumption and pain following arthroscopic shoulder surgery. The ultrasound (US)‐guided supraclavicular brachial plexus block (SCBB) seems to be an alternative technique for arthroscopic shoulder surgery. However, evidence is lacking regarding the impact of SCBB on postoperative pain management and recovery after arthroscopic shoulder surgery. The aim of this study was to compare the effects of SCBB with ISBB in terms of postoperative pain and quality of recovery after arthroscopic shoulder surgery.

“Horizontal butterfly” technique in repair of radial meniscus tears: A biomechanical study

Introduction Radial meniscus tears are seen in young patients, especially with anterior cruciate ligament ruptures. Repair of complete radial meniscus tear is necessary for the meniscus functions. The most important factor for success of the meniscus repair is primary stability, but it is still unknown which technique is ideal repair technique. Aim We developed a new suture technique named Horizontal Butterfly (HB). In this novel technique the contact between meniscal tissue and suture is more than Horizontal Loop (HL) that routinely used today. So, we think that this technique will provide better fixation than HL. We aimed to compare 2 repair techniques (HB vs. HL) using human lateral menisci biomechanically with cyclic loading and load to failure tests. Material-method We used 22 intact lateral meniscus obtained from patients that operated (total knee replacement) for varus gonarthrosis in our clinic. All menisci were cut radially. In the first group (n:11) menisci were repaired with standard horizontal loop technique, and in the second group (n:11) horizontal butterfly technique were used for repair. All specimens were tested with load to failure test after cyclic loading test (500 cycle X 5–30 N). Results Both groups have similar failure load (71,4 ± 17,52 N vs. 77,9 ± 28,49 N; p:0,559) and stiffness (24,46 ± 19,19 N vs. 24,48 ± 15,87 N; p:0,818). HB group has less peak displacement (6,26 ± 1,24 mm vs. 8,4 ± 1,92 mm; p:0,010). Conclusion This novel repair technique decreases the amount of displacement according to standard technique while as strong as standard technique routinely used. In this way; we believe that it will increase the rate of healing in clinical use.

A novel technique in repair of radial meniscus tear: Biomechanical comparison of horizontal cross loop and horizontal loop techniques with cyclic loading

Introduction: Radial meniscus tears are seen in young patients, especially with anterior cruciate ligament ruptures. Repair of complet radial meniscus tear is necessary for the meniscus functions. The most important factor for success of the meniscus repair is primary stability, but it is still unknown which technique is ideal repair technique. Aim: We developed a new suture technique named Cross Horizontal Loop(CHL). In this novel technique the contact between meniscal tissue and suture is more than Horizontal Loop(HL) that routinely used today. So, we think that this technique will provide better fixation than HL. We aimed to compare 2 repair techniques (CHL vs. HL) using human lateral menisci biomechanically with cyclic loading and load to failure tests Materials-Methods: We used 20 intact lateral meniscus obtained from patients that operated (total knee replacement) for varus gonarthrosis in our clinic. All menisci were cut radially. In the first group (n:10) menisci were repaired with standart horizontal loop technique, and in the second group (n:10) cross horizontal loop technique were used for repair. All specimens were tested with load to failure test after cyclic loading test (500 cyclus X 5-30 N). Results: Both groups have similar failure load (71,4±17,52 N vs. 77,9±28,49 N; p:0,559) and stiffness (24,46±19,19 N vs. 24,48±15,87 N; p:0,818). CHL group has less peak displacement (6,26±1,24 mm vs. 8,4±1,92 mm; p:0,010). Conclusions: This novel repair technique decreases the amount of displacement according to standard technique while as strong as standart technique routinely used. In this way; we believe that it will increase the rate of healing in clinical use. Tablo 1. Radial Yırtıkların Gruplara Göre Dağılımı Gruplar Değiskenler Horizontal Cross Horizontal Loop t/Z p n Ort±SS n Ort±SS Peak Displacement (mm) 9 6,26±1,24 11 8,4±l,92 2,880 0,010* Peak Force (N) 9 35,82±1,47 11 38,5±2,67 2,842 0,015* Static Peak Force (N) 9 71,4±17,52 11 77,9±28,49 0,596 0,559* Stiffness (N/mm) 6 24,46±19,19 6 24,48±15,87 0,320 0,818 p<0.05 anlamlılık düzeyidir. * Bağımsız Örneklem T Testi ** Mann Whitney U Testi Schematic drawing of the repair techniques