Murat Korkmaz

A rare pathogen for subacute osteomyelitis in adolescent: Serratia marcescens.

Highlights • Serratia species are rare pathogens for osteomyelitis.• Orthopedic surgeons should be aware of opportunistic microorganism like serratia.• Osteomyelitis is one of the factors for union delay or nonunion, we should be alert.• Osteomyelitis treatment consists of debridement and antibiotics.

Quantitative comparison of a laterally misplaced pedicle screw with a re-directed screw. How much pull-out strength is lost?

Objective Redirecting of a laterally misplaced pedicle screw into the accurate position decreases the pull-out strength due to the reinsertion, lateral wall cortical perforation and widening of the pedicle hole. Thus, this biomechanical study was performed to quantitatively analyze the pullout strength of a redirected laterally misplaced pedicle screw into the accurate position. Methods Thirty pedicules of 15 bovine vertebrae were separated to 3 groups, according to the screw placement method: 1) standard flawless trajectory; 2) trajectory with lateral pedicle wall perforation; 3) trajectory with lateral wall perforation redirected to the standard trajectory. Samples were placed on a universal testing machine and pullout loads were measured. Kruskal-Wallis test was utilized within 95% confidence interval and p value <0.05 to test for the statistical significance. Results The mean pullout strength was 2891±654,2 N(1383-3814,5) in Group 1; 817,8±227,6 N(308,6-1144,9) in Group 2 and 2081,1±487,7 N(1583,5-2962,5) in Group 3. The results found out to be statistically significant (p<0.05). Inter-group comparisons revealed that lateral pedicle wall perforation significantly decreases the pullout strength (p<0.05) and redirection of the screw increases the strength (p<0.05), however it was still weaker than the screws with flawless standard trajectory but this was not statistically significant (p>0.05). Conclusion The results of this study confirm that pullout strength of pedicle screw decreases by approximately 71% when the lateral wall is perforated and decreases 28% after redirection to the accurate position.

Aarskog-Scott syndrome: An unusual cause of scoliosis

A 16-year-old boy who had been diagnosed previously as Aarskog-Scott syndrome (AAS), referred to our clinic with shoulder asymmetry for 1 year. Results of spine examination showed a 52° right thoracic curve at T3-T11. Surgery was planned, and T1–L1 posterior instrumentation and fusion were performed. After surgery, satisfactory correction was achieved, and during 10 years follow-up, the patient had no complaints. AAS is a X-linked genetic disorder with facial, genital, and skeletal manifestations. Scoliosis is not reported as a typical finding of AAS, and there is no reported case in the English literature. Due to mutation affecting the developing skeleton tissue, spinal deformities may develop. In our case, concave side fusion was seen at the deformity. Although we do not know any specific pattern of the scoliotic deformity of this syndrome, surgical correction of the deformity can be difficult because of the premature fusion at these levels.

A minimally invasive technique using a modified stoppa approach for periacetabular osteotomy: A preliminary cadaveric study

Background: Developmental hip dysplasia is diagnosed when the femoral head is not sufficiently covered by the acetabulum. Anterior and lateral cover deficiency is seen, as a result a dysplastic hip joint. Various incision modifications have been developed because of the muscle dissection and wide wound scar in Smith-Peterson incision, which was originally used in Bernese osteotomy. This study evaluates applicability of the modified Stoppa approach in the performance of Bernese periacetabular osteotomy (PAO). Materials and Methods: Ten hemipelvises of five donor cadavers were used. The transverse Stoppa incision was made 2 cm over the symphysis pubis for quadrilateral surface exposure and pubic and ischial bone osteotomies. The second skin incision, a few centimeters lateral to the original incision, was made along the tensor fascia lata. Iliac bone osteotomy was performed starting just above the rectus femoris insertion. The displacement of the osteotomy was measured clinically and radiographically. Results: The mean anterior coverage calculated with center-edge angle was improved from 22.8° ±2.8 (range 20° min–28° max) preoperatively to 44.1° ± 3.7 (range 36° min–48° max). The displacement of the osteotomy at the iliopectineal line calculated on the iliac inlet view radiographs was 22.1 ± 3.4 mm (range 15 mm min–26 mm max). The clinical amount of the anterior displacement on the cadavers was 17.8 ± 3.35 mm (range 11 mm–21 mm) and lateral displacement was 20.3 ± 3.23 mm (range 15 mm–24 mm). The amount of the posterior intact bone enlargement at the quadrilateral surface was 5.3 ± 0.48 mm. Conclusion: This less traumatic two-incision exposure is an adequate technique for Bernese PAO, allowing the bone to be cut under direct visual observation and reducing the need to use fluoroscopy.

Effect of growing rod on sagittal and spinopelvic parameters in early-onset scoliosis patients.

Growing rod is a commonly used surgery for early-onset scoliosis (EOS). However, the effect of growing-rod lengthening on the spinopelvic alignment is unclear. In this study, 21 EOS patients treated by growing rod were evaluated retrospectively and thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI) , sacral slope (SS), pelvic tilt (PT), and sagittal vertical axis (SVA) were measured. Preoperatively, the mean TK, LL, PI, PT, SS, and SVA were 27.4°, 35.2°, 43.8°, 7.5°, 33.8°, and 47.7 mm respectively. After the last lengthening, TK, LL, PI, PT, SS, and SVA were 28.3°, 28.06°, 41.4°, 7°, 5.2°, and 42.6 mm, respectively. The sagittal plane parameters in our EOS patients were not significantly altered during the lengthening period.

Evaluation of Proximal Junctional Kyphosis following Posterior Thoracic Instrumentation: The Effect of Posterior Anatomical Structures and Facet Joints: A Biomechanical Analysis on Fresh Sheep Spine

Introduction Proximal junctional kyphosis (PJK) has traditionally been defined by a 10 degree or greater increase in kyphosis at the proximal junction as measured according to Cobb method. Especially patients who have advanced spine deformity are prone to PJK and it is related with aggressive treatment protocols. In this biomechanical study, we aimed to evaluate interspinous ligament complex disruption and facet joint degeneration on PJK development. Material and Methods Randomly selected 21 sheeps were operated via posterior approach and pedicle screws were instrumented from T2 to T7. Three groups with seven samples were established to create junctional disruption. First group selected as control group (CG), of which posterior soft tissue and facet joints were preserved intact. In the second group (spinous group, SG), interspinous ligament complex which one segment cranial to UIV has been transected, and third group (facet group FG) where facet joint excision was performed. 25 N, 50 N, 100 N, 150 N, and 200 N forces applied at frequency of 5 Hz as 100 cycles axial to the samples. To determine strength of proximal junctional area in static loading 250 N, 275 N, and 300 N forces was applied. Changes in the proximal junctional region were defined radiologically. Lateral X-ray views were taken to measure interspinous distances, kyphosis angles, and discus heights. Abnormal PJK was defined by a proximal junctional angle greater than 10 degree and at least 10 degree greater than the corresponding preoperative measurement. Results In CG group, average interspinous distance was 6.6 ± 1.54 mm and kyphosis angle was 2.2 ± 0.46 degree before biomechanical testing, and they were measured as 9.4 ± 1.21 mm and 3.3 ± 0.44 degree respectively after forces applied to samples. In SG group, average interspinous distance was 6.2 ± 1.71 mm and kyphosis angle was 2.7 ± 1.09 degree before the experiment, and they were measured as 20.8 ± 5.66 mm and 15.1 ± 2.33 degrees, respectively, after biomechanical testing. In FG group, average interspinous distance was 4.8 ± 1.15 mm and kyphosis angle was −1 ± 4.14 degree before experiment, and they were measured as 11.1 ± 1.96 mm and 11 ± 2.87 degree, respectively, after forces applied to samples. Statistically significantly junctional kyphosis development was detected on both FG and SG group than group control group (p < 0.05). PJK was seen significantly more frequently on SG group than FG group (p < 0.05). Disc distances were similar in all groups (p > 0.05). Conclusion Protecting interspinous ligament complex and facet joint on surgical treatment of spine deformity is mandatory to prevent PJK. To our knowledge, this is the first biomechanical study that reveals that the interspinous ligament complex is more effective in preventing PJK development than facet joints.

Comparison of fixation techniques in Vancouver type AG periprosthetic femoral fracture: a biomechanical study.

OBJECTIVE The purpose of this study was to biomechanically compare cable, trochanteric grip plate, and locking plate techniques in Vancouver type AG fracture model in an in vitro test environment. METHODS Fifteen pieces of fourth-generation synthetic femora were separated into 3 groups of 5 models each. A greater trochanteric fracture model was created after femoral stem implantation. Group 1 was fixated with only cable, Group 2 with trochanteric grip plate, and Group 3 with locking plate. Horizontal stiffness, axial stiffness, and failure loads were compared between the groups. RESULTS In horizontal compression tests, Group 3 had the highest values, but the only statistically significant difference was between the locking plate group and cable group. Axial distraction test results showed that mean stiffness of Group 1 was 94.6±9.44 N/mm, that of Group 2 was 174.8±28.64 N/mm, and that of Group 3 was 185.6±71.64 N/mm. While locking plate versus cable fixation and grip plate fixation versus cable fixation showed statistically significant differences (p<0.05), comparison of locking plate versus grip plate fixation showed no statistically significant difference (p>0.05). In axial failure load test, Group 3 had the highest results. The only significant difference was between the locking plate and cable groups (p<0.05). CONCLUSION In Vancouver type AG fractures stable fixation may be achieved with grip plate fixation and locking plates, with the former ensuring more stable osteosynthesis.