Szymon Feliks Dragan

Cytokine induction of sol–gel-derived TiO 2 and SiO 2 coatings on metallic substrates after implantation to rat femur

Material surface is a key determinant of host response on implanted biomaterial. Therefore, modification of the implant surface may optimize implant–tissue reactions. Inflammatory reaction is inevitable after biomaterial implantation, but prolonged inflammation may lead to adverse reactions and subsequent implant failure. Proinflammatory activities of cytokines like interleukin (IL)-1, IL-6, and tumor necrosis factor-alpha (TNF-α) are attractive indicators of these processes and ultimately characterize biocompatibility. The objective of the study was to evaluate local cytokine production after implantation of stainless steel 316L (SS) and titanium alloy (Ti6Al4V) biomaterials coated with titanium dioxide (TiO2) and silica (SiO2) coatings prepared by sol–gel method. Biomaterials were implanted into rat femur and after 12 weeks, bones were harvested. Bone–implant tissue interface was evaluated; immunohistochemical staining was performed to identify IL-6, TNF-α, and Caspase-1. Histomorphometry (AxioVision Rel. 4.6.3 software) of tissue samples was performed in order to quantify the cytokine levels. Both the oxide coatings on SS and Ti6Al4V significantly reduced cytokine production. However, the lowest cytokine levels were observed in TiO2 groups. Cytokine content in uncoated groups was lower in Ti6Al4V than in SS, although coating of either metal reduced cytokine production to similar levels. Sol–gel TiO2 or SiO2 coatings reduced significantly the production of proinflammatory cytokines by local tissues, irrespective of the material used as a substrate, that is, either Ti6Al4V or SS. This suggests lower inflammatory response, which directly points out improvement of materials’ biocompatibility.

Increased Radiation but No Benefits in Pedicle Screw Accuracy With Navigation versus a Freehand Technique in Scoliosis Surgery

Background The clinical value of pedicle screws in spinal deformity surgery is well known; however, screw insertion is demanding and sometimes associated with complications. Navigation systems based on intraoperatively obtained three-dimensional (3-D) images were developed to minimize pedicle screw misplacements. However, there is a lack of data confirming superiority of navigation above other techniques. There are also concerns regarding increased radiation used during the procedure. Questions/purposes The purposes of this study were (1) to compare accuracy of the two methods of pedicle screws placement: intraoperative 3-D image navigation versus a freehand technique in patients with idiopathic scoliosis; and (2) to assess the radiation dose received by patients with both methods. Methods Between 2014 and 2016, 49 patients underwent posterior spinal fusion with all pedicle screw constructs for idiopathic scoliosis performed by two surgeons. The study design involved alternating the use of the freehand technique and navigation to position pedicle screws in consecutive patients, forming groups of 27 patients with 451 navigated screws and 22 patients with 384 screws positioned freehand. The two groups did not differ in age, sex, or magnitude of deformity. Two observers not involved in the treatment evaluated the position of the screws. The pedicle breach was assessed on intraoperatively obtained 3-D O-arm® scans according to a grading system: Grade 0 = no pedicle wall violation; Grade 1 = perforation ⩽ 2 mm; Grade 2 = 2 to 4 mm; and Grade 3 = perforation > 4 mm. Grades 0 and 1 were considered properly positioned and Grades 2 and 3 represented malposition. Results In terms of accuracy, we found no differences, with the numbers available, between the freehand and navigated groups in terms of the proportion of screws that were properly positioned (96% freehand and 96% in the navigation group, respectively; p = 0.518). Grade 3 pedicle screws were observed only in the freehand group and were all located in the upper thoracic spine. Patients undergoing navigated pedicle screw placement received a greater mean radiation dose than those whose screws were placed freehand (1071 ± 447 mGy-cm versus 391 ± 53 mGy-cm; mean difference, 680 mGy-cm; 95% confidence interval, 217-2053 mGy-cm; p < 0.001). Conclusions In patients with moderate idiopathic scoliosis undergoing primary surgery, we did not observe benefits of pedicle screw placement with CT-based navigation, but the patients experienced greater exposure to radiation. Level of Evidence Level III, therapeutic study.

Clinical factors affecting lower limb torsional deformities treatment with the Ilizarov method

INTRODUCTION One of the many uses of the Ilizarov fixator is for torsional deformities correction. Rotational and translational bone displacement related to torsional deformities correction includes the additional tension stresses, which affect the biology of the regenerated bone. Understanding the clinical factors will assist in designing the optimal treatment strategy, thus possibly improving the outcomes. PATIENTS AND METHODS It was case series retrospective study. The study examined 56 patients. The mean follow-up time was 5 years and 6 months. The mean age at the start of treatment was 19 years and 10 months. Patients underwent derotational corticotomies of distal metaphysis of the femur or proximal metaphysis of the tibia using the Ilizarov method. In these patients, following derotational corticotomies with the Ilizarov method, numerous variables were defined and their effect evaluated: the selected treatment strategy, the rate, size, type, and level of derotation on complications, the alignment index, the correction coefficient, the elongation index, and deformation correction factor. RESULTS The differences in the values of alignment index and deformation correction factor in this study subgroups were not statistically significant. We found differences in the elongation index and correction coefficient in a number of subgroups. DISCUSSION In the case of correcting torsional deformation without significant elongation, acute correction and with a value of >30° does not significantly affect the results. Treatment strategy, type and level of derotation had no major influence on torsional deformities treatment. LEVEL OF EVIDENCE Case-control study III.

Balance and lower limb loads distribution after Ilizarov corticotomy

INTRODUCTION Normal balance and symmetric distribution of lower limb loads are associated with adequate muscle strength, joint mobility and proprioception. The aim of this study was to analyze the distribution of lower limb loads and balance prior to and after axis correction and lengthening with Ilizarov method. MATERIALS AND METHODS The prospective analysis included 20 patients from our clinic, who have been subjected to distraction-corrective lower limb corticotomies with the Ilizarov method in 2014-2015. Balance and distribution of lower limb loads were determined with a pedobarographic platform. RESULTS Prior to the surgery, mean loads on affected and non-affected limbs corresponded to42%and58%of body weight, respectively. Mean loads on affected and non-affected limbs during the postoperative examination did not differ significantly. Mean path length of the center of gravity prior to and after the surgery amounted to143.27 cm and 125.11 cm, respectively. Mean area of the center of gravity was 7.81 cm2prior to the surgery and 5.81 cm2after the procedure. DISCUSSION Our present study showed that distraction-corrective Ilizarov corticotomy may provide more symmetric distribution of lower limb loads and improvement of balance. This outcome should be considered satisfactory from the perspective of the locomotor system statics. Corticotomies with Ilizarov method provide symmetric distribution of loads between non-affected and operated limb.

Radiological evaluation of ankle arthrodesis with Ilizarov fixation compared to internal fixation

INTRODUCTION We asked whether the type of ankle joint arthrodesis stabilization will affect: (1) rate of union, (2) rate of adjacted-joint arthritis, (3) malalignment of the ankle joint. MATERIAL AND METHODS We retrospectively radiological studied 62 patients who underwent ankle arthrodesis with Ilizarov external fixator stabilization (group 1,n=29) or internal stabilization (group 2,n=33) from 2006 to 2015. Radiologic outcomes were mesure by: (1) rate of union, (2) rate of adjacent-joint arthritis, (3) malalignment of the ankle joint. The Levenes test,Mann-Whitney U test and Students t-test were used to the statistical analyses. RESULTS Ankle fusion was achieved in 100% of patients treated with external fixation and in 88% with internal stabilization. Desired frontal plane alignment was achieved in 100% of patients with external fixation and 76% with internal stabilization. Desired sagittal plane alignment was achieved in 100% of external fixation and 85% of internal stabilization. A total of 14 (48.3%) patients from group 1 showed a radiographic evidence of pre-existing adjacent-joint OA. The radiographic evidence of pre-existing adjacent-joint OA was also found in 27(81.8%) subjects from group 2. Alterations of adjacent joints were also found on postoperative radiograms of 19 (65.5%) patients subjected to Ilizarov fixation and in all 33 patients from group 2. DISCUSION Ilizarov fixation of ankle arthrodesis is associated with lower prevalence of adjacent-joint OA and ankle joint misalignment,and with higher fusion rates than after internal fixation.Although achieving a complex ankle fusion is generally challenging,radiological outcomes after fixation with the Ilizarov apparatus are better than after internal stabilization.

Assessment of the distribution of load on the lower limbs and balance before and after ankle arthrodesis with the Ilizarov method

Ankle arthrodesis with the Ilizarov method is an accepted form of treatment of advanced degenerative changes of the ankle joint. Incorrect balance and load distribution on the lower limbs may result in pain and dysfunction. The aim of the study was to assess the change of balance and load distribution in lower extremities in patients before and after ankle arthrodesis with the Ilizarov method. Between 2013 and 2016, ankle arthrodesis using the Ilizarov method was performed on 21 patients. The evaluation of balance and percentage of load in each lower limb was performed before the surgery and during the follow-ups. The evaluation was performed using a Zebris pedobarographic platform. Before the surgery, the patients exhibited an average load of 41.9% of body weight in the affected limb, whereas the load in the healthy limb was 58.1%. The difference was statistically significant (p = 0,000031). In two years follow-up, the average load in the treated limbs was 48.19%, whereas the healthy limbs were subjected to an average load of 51.81%. In preoperative tests, the average path length of the center of gravity was 161.55 cm; postoperatively, the average path length of the center of gravity was 129.7 cm (p = 0.00003206). Preoperatively, the average area of the center of gravity was 18.85 cm2; it decreased to 6.19 cm2 (p = 0.000032) postoperatively. Arthrodesis of the ankle with the Ilizarov method improved the statics of the musculoskeletal system by improving the distribution of loads in the lower limbs as well as balance. However, it failed to restore the parameters of a healthy person. Advanced degenerative changes of the ankle disturb the biomechanics of the entire lower limb.

Three-dimensional printing as a technology supporting the treatment of lower limb deformity and shortening with the Ilizarov method

BACKGROUND Treatment of multiplanar deformities, especially in younger children, requires construction of a complex Ilizarov fixator, frequently with small dimensions. The aim of this study is to verify clinical application of a3D-printed bone model in treatment with the Ilizarov method. METHODS The study involved a 6-year-old child in whom clinical and radiological examination revealed multiplanar deformity of the right leg. Then, 3D models of individual bones were printed by means of additive manufacturing and were used as a scaffold to install the Ilizarov apparatus. To compare the expected and factual axial correction and lengthening, we measured spatial orientation of bone fragments three times. The factual axial correction and lengthening were determined with a photometric technique. RESULTS Ilizarov fixator with a configuration developed using a 3D model of the treated bone was mounted on the patients leg. Corticotomy was carried out at the proximal metaphysis of the right tibia, along with osteotomy of the right talus. The treatment resulted in a 3.5-cm lengthening of the limb and a 7° correction of valgus angle. The values of actual lengthening and axial correction were 4.1% lower than the expected values of these parameters. INTERPRETATION Orthopedists should consider differences between the expected and actual lengthening and axial correction in planning treatment with the Ilizarov method. Three-dimensional printing is a useful technology that can be used to support treatment with the Ilizarov method.

The Impact of Direct Vertebral Rotation (DVR) on Radiographic Outcome in Surgical Correction of Idiopathic Scoliosis

Introduction: Recent developments of spinal instruments allow to address nearly all components of idiopathic scoliosis. Direct vertebral rotation (DVR) maneuver was introduced to correct apical axial vertebral rotation. It is however still not well established how efficiently DVR affects results of scoliosis correction. The object of the study was to evaluate en bloc apical vertebral rotation (DVR) and its impact on coronal and sagittal correction of the spine in patients undergoing surgical scoliosis treatment. Material and methods: 36 consecutive patients who underwent posterior fusion with pedicle screws only constructs for idiopathic scoliosis. 15 patients (20 curves) were corrected by rod derotation only and 21 patients (26 curves) had both rod derotation and DVR. Curve measurements were performed on x-rays obtained before and post operatively - coronal curves, kyphosis (T2-T12, T5-T12). Spine flexibility was assessed on prone bending x-rays. Apical axial rotation was determined on CT scans obtained intraoperatively and postoperatively. Rotation angle (RAsag) was measured according to Aaro and Dahlborn. Results: We observed reduction of RAsag in all patients, however in DVR group decrease was greater, by 31.8% comparing to non-DVR group, by 8.6% (p=0.0003). Mean coronal correction in DVR group was 68.8% and in rod derotation group without DVR 55% (p=0.002). No significant correlation was found between degree of derotation obtained and coronal correction. In DVR group T2-T12 kyphosis has increased in 28 (65%) patients whereas in non DVR group in 31 (69%) cases. Mean value of T2-T12 kyphosis growth was 16.7% in DVR and 22.1% in non DVR group. These differences however did not occur statistically significant. Conclusions: Direct vertebral rotation (DVR) manoeuvre reduces significantly apical rotation of the spine, enhances ability of coronal correction and it does not reduce thoracic kyphosis.