The effect of posterior tibial slope on anteroposterior stability in posterior cruciate retaining total knee arthroplasty.

BACKGROUND: It has been suggested that the posterior tibial slope (PTS) plays an important role in increasing the anteroposterior stability following total knee arthroplasty. Although the relationship between the PTS and the flexion range has been investigated many times, studies on the relationship between PTS and anterior-posterior stability are limited. The primary aim of this study was to investigate the relationship and effects of PTS on anteroposterior stability in posterior cruciate retainer total knee arthroplasty. METHODS: 154 primary TKAs were identified retrospectively to analyze the any association between PTS and anteroposterior laxity following posterior cruciate-retaining total knee arthroplasty in the overall study populations. Anteroposterior displacement was measured at the final follow-up based on the following two procedures: KT-1000 arthrometer and sagittal drawer radiographic images. In addition, the relationship between PTS and functional scores-ROM was examined. RESULTS: There was no correlation between patients' posterior tibial slope and postoperative VAS (r: -0.060, p:0.544), WOMAC (r:0.037, p:0.709), KSS (r: -0.073, p:0.455). In addition, there was no significant correlation between postoperative knee ROM and postoperative PTS (r:0.159, p:0.106). Moreover, no correlation was found between KT-1000 arthrometer and 20 degrees AP translation with PTS. There was a negative correlation between PTS and 70 degrees AP translation (r: -0.281, p:0.008). CONCLUSIONS: This study aimed to clarify the association between instability and AP laxity in flexion of implanted knees, and to determine what degree of AP laxity results of instability. A fundamental finding of this study was that; the optimum TS angle to increase anterior-posterior stability after total knee arthroplasty is between ≥ 4 to < 6 degrees, we also proved that there is no relationship between stability and patient satisfaction.

Effect of lengthening speed on the quality of callus and complications in patients with congenital pseudarthrosis of tibia.

PURPOSE: This study aims to evaluate the effect of lengthening speed on the quality of callus and complications during distraction osteogenesis and describe an optimal lengthening speed in patients with congenital pseudarthrosis of tibia (CPT). METHODS: Twenty-seven patients with CPT with a minimum follow-up of 36 months who underwent limb lengthening surgery between 1997 and 2016 with external fixator only were included in this study. All patients underwent lengthening procedures after achieving complete bone union in this study. Regenerate quality is evaluated according to the Li classification on the X-ray taken one month after the end of the distraction period. Complications were noted in post-operative follow-up period. Receiver operator characteristics (ROC) curve analysis was performed to obtain optimal lengthening speed for these patients. RESULT: The mean age at the time of surgery was 5.74 years. The mean lengthening speed was 0.596 mm/day. Follow-up period of 136.14 months with a mean lengthening period of 92.4 days. Mean amount of lengthening was 5.44 cm for patients with CPT. Total rate of callus with good morphological quality was calculated as 66%. According to ROC analysis, optimal cut-off values of lengthening speed for the obtaining good morphological quality callus was 0.564 mm/day for tibial lengthening in CPT. There was a significantly positive correlation between complication rate and lengthening speed for each group. CONCLUSION: We recommend a mean lengthening rate of 0.56mm/day for the lengthening procedures with external fixator in patients with CPT who had complete bone union at the area of pseudarthrosis.

Effect of radiofrequency microtenotomy on degeneration of tendons: an experimental study on rabbits.

INTRODUCTION: Radiofrequency microtenotomy is used to enhance healing by increasing vascularity in the degenerated tendon. In the present study, the effect of radiofrequency microtenotomy (Rf-mt) treatment on tendon degeneration was investigated. MATERIALS AND METHODS: A total of 32 New Zealand rabbits were enrolled in the current study. Experimental degeneration was performed by injecting prostaglandin E1 (PGE1) into the bilateral Achilles tendons of rabbits. After excluding 4 rabbits with an infection on the injection site, 4 other rabbits were sacrificed to define the histopathologic changes in the tendons. The remaining 24 rabbits were divided into 2 groups: the control group and the Rf-mt group. In the control group, the Rf-mt device was only applied to the Achilles tendon without running the device. In the Rf-mt group, the Rf-mt device was applied bilaterally at the fourth energy level for 500ms to an area within 2cm proximal to the insertion site at 0.5cm intervals in order to form a grid. Six rabbits from each group were sacrificed at 6 and 12 weeks. The Achilles tendons were evaluated histopathologically by a modified Movin scale and by immunohistopathologic staining for vascular endothelial growth factor and type 4 collagen. RESULTS: After the PGE1 injection, findings similar to chronic degenerative tendinopathy were observed. The Rf-mt group showed significant improvement in vascularity in the histopathological and immunohistochemical examination (P<0.05). However, there was no significant difference in healing between the control and Rf-mt groups (P>0.05). CONCLUSIONS: Rf-mt treatment increases vascularity in degenerated tendons but does not create difference to facilitate the healing process comparing control group.

Tracing the disc: The novel qualitative morphometric MRI based disc degeneration classification system.

Background: This study aimed to develop a classification system for lumbar disc degeneration using routine magnetic resonance images (MRIs) that is easily applicable and unaffected by existing classifications' limitations, and to compare its reliability, reproducibility, and discriminative power to the widely used Pfirrmann classification. Methods: Five features were graded. This new classification system has eight grades, with at least one of these five features altering each grade. The T2-weighted sagittal images were acquired using a rapid spin-echo sequence with a repetition time of 2680 to 4900 milliseconds, an echo time of 100 to 109 milliseconds, and an echo train length of 17. Slice thick was 4 mm and the display field of view was 32 × 32 cm. The new classification system used five features: signal intensity, disc height, disc boundary regularity, and nucleus annulus separation. Increased signal intensity, decreased height, decreased regularity, and decreased nucleus-annulus separation indicated degeneration. Four raters classified 400 discs from 80 patients using the Pfirrmann and Novel systems. Statistical analyses were conducted to investigate reliability and correlation. Results: The overall ICC and kappa values were found to be higher in the novel classification. (0.988 indicating excellent agreement for ICC and 0.76/0.94 indicating good-very good agreement for kappa). The Kendall tau c value, which shows the correlation between the two classifications and indicates the validity of the new classification, was 0.872, which is very strong. Through the use of cross-tabulations, the discriminatory power of the two newly added classification criteria was determined. Conclusions: This study demonstrates the intra-rater and inter-rater reliability of an easy-to-use, discriminative novel morphometric MRI based classification system for lumbar disc degeneration. The differentiation of grades based on five distinct criteria may generate novel hypotheses regarding treatment selection and response monitoring, as well as new insights into the study of disc degeneration.

Coronal plane fractures of the distal humerus involving the capitellum and trochlea treated with open reduction internal fixation.

INTRODUCTION: Coronal plane fractures of the distal humerus involving the capitellum and trochlea are rare. Treatments have evolved from closed reduction to open reduction and internal fixation (ORIF) to achieve a stable joint that allows early mobilization. BACKGROUND: We determined the functional outcomes of treating coronal plane fractures of the distal humerus with ORIF. METHODS: We reviewed the records of all patients with coronal plane fractures of the distal humerus treated by ORIF. Fractures were classified according to Bryan and Morrey. Cannulated screws were used for fixation. All patients were evaluated using the Mayo Elbow Score Performance Index (MEPI) and disabilities of the arm, shoulder, and hand (DASH) scores at least 1 year later. RESULTS: Of the 18 patients evaluated (12 women), the mean (SD) age was 45.3(16.5) years (range 16-70). There were seven Type-I, five Type-III, and six Type-IV fractures. Mean follow-up was 43.6 (38.1) months (range 12-120). The mean elbow range of motion in sagittal plane at last follow-up ranged from 8.9° to 132.8°. The mean MEPI score was 86.7 (15.2) points (range 60-100), corresponding to 12 excellent, 2 good, and 4 fair outcomes. The mean DASH score was 15.3 (13.5) points (range 17-35.8). Heterotrophic ossification developed in one patient with delayed fixation; 14 patients with excellent or good results returned to their previous activity levels. Functional scores did not differ by age, sex, or fracture types (P > 0.05 for all comparisons). CONCLUSION: ORIF with cannulated screws, which maintain a stable anatomic articular position, provides satisfactory results in coronal plane fractures of the distal humerus. LEVEL OF EVIDENCE: Level IV case series.

Comparison of arthrodesis, resurfacing hemiarthroplasty, and total joint replacement in the treatment of advanced hallux rigidus.

The purpose of the present study was to compare the functional results of arthrodesis, resurfacing hemiarthroplasty, and total joint replacement in hallux rigidus. The data from patients treated from 2006 to 2010 for advanced stage hallux rigidus were retrospectively reviewed. A total of 38 patients who had at least 2 years (range 24 to 66 months, mean 31.1) of follow-up were included in the present study. Of the 38 patients, 12 were included in the total joint replacement group (group A), 14 in the resurfacing hemiarthroplasty group (group B), and 12 in the arthrodesis group (group C). At the last follow-up visit, the functional outcomes were evaluated using the American Orthopaedic Foot and Ankle Society-Hallux Metatarsophalangeal Interphalangeal (AOFAS-HMI) scale, visual analog scale (VAS), and metatarsophalangeal range of motion. Significant improvements were seen in the AOFAS-HMI score, with a decrease in the VAS score in all 3 groups. According to the AOFAS-HMI score, no significant difference was found between groups A and B. However, in group C, the AOFAS-HMI scores were significantly lower than in the other groups owing to the lack of motion. According to the final VAS scores, no significant difference was found between groups A and B; however, the VAS score had decreased significantly more in group C than in the other groups. No major complications occurred in any of the 3 groups. After 2 years of follow-up, all the groups had good functional outcomes. Although arthrodesis is still the most reliable procedure, implant arthroplasty is also a good alternative for advanced stage hallux rigidus.

Factors affecting mortality after hip fracture surgery: a retrospective analysis of 578 patients.

PURPOSE: To determine the effect of patient and surgical factors on mortality after hip fracture surgery. DESIGN: Retrospective study. SETTING: Level-one trauma and tertiary referral centers. METHODS: Patients were eligible if they were aged 65 years or older and had undergone surgery for a non-pathological femoral neck or intertrochanteric hip fracture between 2008 and 2011. The primary outcome was mortality: within the first year after surgery, after the first year, and survival as of the last questioning date. Of the 578 eligible patients, 399 (69%) were women; mean age was 79 years; and mean follow-up was 17 months. RESULTS: Mortality during the first year was significantly more frequent in patients aged 80 years or older (67 vs. 33%; P < 0.001). Estimated overall survival was significantly longer in women (43 vs. 37%; P = 0.01). The type of fracture had no impact on mortality (P = 0.96). Patients with high ASA class had a significant effect on mortality (P < 0.001). Surgery timing did not affect mortality in univariate analysis (P = 0.25). The mortality rate for hemiarthroplasty was higher than osteosynthesis options (P = 0.03). The effect of the type of anesthesia on mortality was not significant (P = 0.74). CONCLUSIONS: Older men had the highest risk of mortality within the first year. Patients with ASA ratings of class 3 or 4 need to be evaluated carefully because they appear to be at higher risk of early mortality. Osteosynthesis has a lower mortality than does arthroplasty for hip fracture and thus should be preferred if either treatment is possible. LEVEL OF EVIDENCE: IV.

Revealing the Effect of Spinopelvic Alignment on Hip Disorders.

Background: Hip osteoarthritis (HOA) is a growing burden and one of the leading causes of hip pain. The relationship between the HOA and the alignment of the spinopelvic region has been intensively studied, however the issue remains controversial. Spinopelvic imbalance, HOA, and dysplasia were investigated in relation to sagittal spinopelvic parameters in this study. Methods: We collected computerized tomography (CT) topograms of the pelvis or abdomen from 380 patients. In antero-posterior (AP) topograms, Tonnis grading, center-edge angle (CEA) and Sharp's acetabular angle (AA) measurements were performed on each patient. Lateral topograms were used to evaluate the following spinopelvic parameters for each patient: pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), sacral table angle (STA), lumbar lordosis (LL), proximal lumbar lordosis (PLL), distal lumbar lordosis (DLL), and PI-LL difference. Initially, the cohort was divided into two subgroups based on whether or not they had HOA. Then, they were divided into two subgroups based on whether or not they had dysplasia. Ultimately, it was divided in half based on the PI-LL imbalance. Statistical analyses were conducted to determine the likely correlations between the spinopelvic parameters of these subgroups. In addition, the correlations between spinopelvic parameters were investigated. Results: There were 380 patients evaluated. We found no association between HOA or dysplasia and spinopelvic parameters. In addition, there was no association between PI-LL imbalance and HOA or dysplasia. Conclusion: There was no difference in constant PI and STA angle, besides other variable parameters, between groups having HOA and dysplasia or not. PI-LL imbalance has no effect on HOA and dysplasia.

Does the technique of limb lengthening affect physeal growth in patient with achondroplasia? Comparison of the simultaneous and consecutive tibia and femur lengthening with external fixators.

We aimed to retrospectively investigate and compare patients who underwent bilateral simultaneous and consecutive lengthening surgery of the femur and tibia in terms of the effect on physeal growth. We hypothesize that compared with the sequential lengthening technique, simultaneous lengthening of the bilateral femur and tibia affects physeal growth to a greater extent. Twenty-six patients with achondroplasia who operated in our clinic between 1995 and 2015 for limb lengthening were included in the study. Fourteen patients with bilateral lengthening of the femur and tibia at the same time were named as simultaneous bilateral lengthening (SBL). Twelve patients with bilateral lengthening of the femur and then bilateral tibia lengthening in other sections or vice versa, at a different time was named consecutive bilateral lengthening (CBL). All patients were followed until at least 18 years old. The physeal arrest was measured with predicted final length at the first visit (investigated with the multiplier method), the total amount of lengthening, and final clinical, and radiological length. Mean limb lengthening was 145 mm (48.5%) and 151 mm (46.6%) for simultaneous and consecutive groups respectively. For lower extremity length, the first group reached 527.6 mm while the expected was 447.3 mm. Considering 151 mm lengthening, the mean growth disturbance for the SBL group was 70.7 mm and for the CBL group was 47.5 mm. For total height comparing between two groups, disturbance for height was 80.5 mm and 65.4 mm, respectively. Although there was no statistical difference, simultaneous bilateral femoral and tibial lengthening has more physiological physeal disturbance effects than consecutive lengthening in patients with achondroplasia.

Plate fixation after lengthening with an external fixator in patients with achondroplasia : A comparative study between two centers.

BACKGROUND: This study compared internal fixation with a plate after lengthening (PAL) with an external fixator with the conventional method (CM) in terms of radiologic and clinical outcomes in the lower extremities of patients with achondroplasia. METHODS: In this study 20 patients (50 lower extremity long bones) who underwent PAL or CM were divided into 2 cohort groups. The amount of lengthening, percentage lengthening, external fixator index (EFI), external fixator time, Li regeneration index, complication rate, and knee range of motion (ROM) were compared between the groups. RESULTS: The median age was 9.4 years (range 6-16 years) in the PAL group and 12 years (range 9-16 years) in the CM group (p = 0.01). Males comprised 80% of the patients in the PAL group and 47% of the patients in the CM group (p = 0.02). The median amount of lengthening in the PAL and CM groups was 7.5 cm (range 5.5-9.5 cm) and 6.0 cm (range 5.5-9.0 cm), respectively (p < 0.01). The median percentage of lengthening in the PAL and CM groups was 44.6% (range 20.0-70.1%) and 43.0% (range 20.5-57.3%), respectively (p = 0.01). The median external fixator time in the PAL and CM groups was 127 days (range 94-185 days) and 180 days (range 105-355 days), respectively (p < 0.01). The median EFI in the PAL and CM groups was 21 days/cm (range 10-33 days/cm) and 27 days/cm (range 15-59 days/cm), respectively (p < 0.01). The Li regeneration index was 3 (interquartile range, IQR 2-4) in both groups (p = 0.2). The total complication rate was similar between the groups. CONCLUSION: In patients with achondroplasia, after lengthening with an external fixator, internal fixation with a plate can be a reliable alternative to the conventional method. LEVEL OF EVIDENCE: Level III therapeutic.

An AI based classifier model for lateral pillar classification of Legg-Calve-Perthes.

We intended to compare the doctors with a convolutional neural network (CNN) that we had trained using our own unique method for the Lateral Pillar Classification (LPC) of Legg-Calve-Perthes Disease (LCPD). Thousands of training data sets are frequently required for artificial intelligence (AI) applications in medicine. Since we did not have enough real patient radiographs to train a CNN, we devised a novel method to obtain them. We trained the CNN model with the data we created by modifying the normal hip radiographs. No real patient radiographs were ever used during the training phase. We tested the CNN model on 81 hips with LCPD. Firstly, we detected the interobserver reliability of the whole system and then the reliability of CNN alone. Second, the consensus list was used to compare the results of 11 doctors and the CNN model. Percentage agreement and interobserver analysis revealed that CNN had good reliability (ICC = 0.868). CNN has achieved a 76.54% classification performance and outperformed 9 out of 11 doctors. The CNN, which we trained with the aforementioned method, can now provide better results than doctors. In the future, as training data evolves and improves, we anticipate that AI will perform significantly better than physicians.

Anisotropy of electrical transport in pnictide superconductors studied using Monte Carlo simulations of the spin-fermion model.

An undoped three-orbital spin-fermion model for the Fe-based superconductors is studied via Monte Carlo techniques in two-dimensional clusters. At low temperatures, the magnetic and one-particle spectral properties are in agreement with neutron and photoemission experiments. Our main results are the resistance versus temperature curves that display the same features observed in BaFe(2)As(2) detwinned single crystals (under uniaxial stress), including a low-temperature anisotropy between the two directions followed by a peak at the magnetic ordering temperature, that qualitatively appears related to short-range spin order and concomitant Fermi surface orbital order.

CORONAL PLANE GROWTH MODULATION FOR GENU VALGUM IN SKELETAL DYSPLASIA.

Objective: To investigate the efficiency and rates of correction by hemiepiphysiodesis using 8-plate to manage genu valgum deformity in children with skeletal dysplasia. Methods: Eleven children with skeletal dysplasia (three female, eight male; mean age = 10.5 years; age range = 7-13) who underwent temporary hemiepiphysiodesis using 8-plates for genu valgum deformity were retrospectively reviewed. There were nine bilateral cases and two unilateral cases. The mean follow-up time from the index surgery to the final follow-up was 45 (ranging from 24 to 72) months. Radiographical assessment including preoperative and final follow-up measurements of joint orientation angles and mechanical axis deviation (MAD) were conducted. Results: Deformities were completely corrected in nine lower extremities (45%) and partially corrected in seven extremities (35%). In four extremities of two children with Morquio syndrome, MAD worsened. The correction rate of MAD was 1.25 ± 1.62 mm/mo. Conclusion: Though hemiepiphysiodesis using 8-plate requires a longer treatment period, it seems to be an effective treatment for correction of genu valgum in children with skeletal dysplasia. Level of Evidence IV, Case Series.

Objetivo: Investigar a eficiência e as taxas de correção da hemiepifisiodese usando placa-8 no tratamento da deformidade de geno valgo em crianças com displasia esquelética. Métodos: Foram avaliadas retrospectivamente 11 crianças com displasia esquelética (três meninas e oito meninos; idade média = 10,5 anos; faixa etária = 7-13) que foram submetidas à hemiepifisiodese temporária com placa-8 devido à deformidade do geno valgo. Havia nove casos bilaterais e dois casos unilaterais. O acompanhamento médio desde a cirurgia de implante até o acompanhamento final foi de 45 (variação de 24 a 72) meses. Foi feita avaliação radiográfica incluindo medidas de acompanhamento pré e pós-operatórias dos ângulos de orientação da articulação e desvio mecânico do eixo (MAD). Resultados: As deformidades foram completamente corrigidas em nove extremidades inferiores (45%) e parcialmente corrigidas em sete (35%). Em quatro extremidades de duas crianças com síndrome de Morquio, o MAD piorou. A taxa de correção do MAD foi de 1,25 ± 1,62 mm/mês. Conclusão: Embora a hemiepifisiodese com placa-8 necessite de um período de tratamento mais longo, a técnica parece ser um tratamento eficaz para a correção do geno valgo em crianças com displasia esquelética. Nível de Evidência IV, Série de Casos.

Temporary Epiphysiodesis Using the Eight-Plate in the Management of Children with Leg Length Discrepancy: A Retrospective Case Series.

Background: Although eight-plates have been shown to be effective in correcting angular deformities of the knee, the literature is scarce regarding the efficiency of this method in treatment of children with LLD. Objectives: The aim of this study was to determine the efficiency, rates of correction and complications of epiphysiodesis using eight-plate in the management of children with leg length discrepancy (LLD). Methods: Eleven consecutive patients with LLD (7 boys, median age = 9, age range 6-11 years) who were treated by temporary epiphysiodesis using eight-plates were retrospectively reviewed and included in the study. The main indication for temporary epiphysiodesis was an LLD between 2 and 5 cm in all patients. LLD and lower limb alignment were examined on lower extremity weight-bearing radiography preoperatively and at skeletal maturity. Longitudinal correction rate was calculated. The final LLD was categorized as ''good result'' (final LLD < 1.5 cm), ''fair result'' (1.5-2 cm), and ''poor result'' (> 2 cm). Results: The mean treatment period with the eight-plate was 44 (min to max = 32-72) months, and the mean follow-up from the index surgery to the final follow-up was 62 (min to max = 39-106) months. The mean LLD was significantly reduced from 39 (range 25-50) mm preoperatively to 22.40 (range 6-55) mm postoperatively (p = 0.006). The mean longitudinal correction rate was found to be 0.48 mm/mo. Radiographic evidence of lower limb deformity in frontal and sagittal planes was determined in neither preoperative nor postoperative deformity analysis. No major complications were recorded. Conclusion: For the management of children with LLD of 2-5 cm, temporary hemiepiphysiodesis using the eight-plate seems to be an effective treatment with low complication rates.

IS VOLAR PLATING IN DISTAL RADIUS FRACTURES SAFE REGARDING PRONATOR QUADRATUS?

Objective: This study aimed to investigate whether isokinetic strength decrease significantly after using volar plating for distal radius fractures and evaluate the pronator quadratus muscle regarding atrophy. Methods: This study took place between 2011 and 2015 and included 18 distal radius fracture patients (group 1) who were treated via volar plating at least one year prior and 14 healthy controls (group 2). All participants were tested isokinetically. Grip strength, radiological evaluation, wrist range of motion, disabilities of the arm, shoulder, and hand and visual analog scale scores were assessed for clinical and functional outcomes. Ultrasonography evaluated the pronator quadratus muscle thicknesses. Results: The peak supination torque (PT) and supination work per repetition (WPT) strength values significantly decreased (p:0.039, p:0.025, respectively). Although we determined an 11% pronation PT deficit and a 19% pronation WPT deficit, neither were significant. In group 1, the pronator quadratus muscle thickness decreased 5.9% ± 13.3 in the radial area and 9.7% ± 10.5 in the interosseous area according with ultrasonography; these results were not statistically significant compared to group 2. All clinical and functional outcomes were not statistically significant between the groups. Conclusion: The use of volar plating after distal radius fractures is a safe method regarding isokinetic strength and pronator quadratus muscle atrophy. Level of evidence III; Retrospective case-control study .

Objetivo: Este estudo teve como objetivo investigar se as forças isocinéticas diminuem significativamente após o uso de placa volar para tratamento de fraturas do rádio distal e avaliar o músculo pronador quadrado quanto à atrofia. Métodos: Este estudo realizado entre 2011 e 2015 incluiu 18 pacientes com fratura do rádio distal (grupo 1) que tenham sido tratadas com placa volar pelo menos um ano antes e 14 pessoas saudáveis como controle (grupo 2). Todos os participantes foram testados isocineticamente. Força de preensão, avaliação radiológica, amplitude de movimento do punho, deficiências do braço, ombro e mão e escores da escala visual analógica foram avaliados clinica e funcionalmente. A ultrassonografia avaliou a espessura do músculo pronador quadrado. Resultados: A força máxima do torque de supinação (TM) e do trabalho por repetição (ER) de supinação diminuíram significativamente (p: 0,039, p: 0,025, respectivamente). Embora tenhamos determinado um déficit de TM de pronação de 11% e um déficit de ER de pronação de 19%, nenhum dos dois foi significativo. No grupo 1, a espessura do músculo pronador quadrado diminuiu 5,9% ± 13,3 na área radial e 9,7% ± 10,5 na área interóssea, segundo ultrassonografia; estes resultados não foram estatisticamente significativos em comparação com o grupo 2. Nenhum resultados clínico ou funcional foi estatisticamente significativo entre os grupos. Conclusão: O uso de placa volar após fraturas do rádio distal é um método seguro em relação à força isocinética e atrofia do músculo pronador quadrado. Nível de evidência III; estudo retrospectivo de caso-controle .

The Relationship Between Limb Lengthening Rate and Callus Quality in Patients with Achondroplasia.

Objectives: This study investigated the effect of the femur, tibia, and humeral lengthening rate in patients with achondroplasia and regenerated bone quality. Methods: The records of the patients with achondroplasia who underwent limb lengthening surgery for both upper and lower extremities between 2002 and 2019 were retrospectively reviewed. Bone formation regeneration was evaluated in each segment at anteroposterior and lateral radiographs and the callus quality was determined at the first month of the consolidation period according to Li's classification system. Results: This study included 42 (28 females and 14 males), 38 (26 females and 12 males), and 17 (11 females and 6 males) patients with bilateral femoral, bilateral tibial, and bilateral humeral lengthening. The mean lengthening rate was 0.920 ± 0.23 (range, 0.53-1.67), 0.813 ± 0.17 (range, 0.51-1.26), and 1.02 ± 0.26 (range, 0.58-150) mm/day in the femoral, tibial, humeral groups, respectively. In the femoral group, 75% femur with good morphological quality, 56.6% good morphological quality in tibial group and 55.9% good morphological quality in humeral group. Statistically significant relationships were found between femoral lengthening rate and callus quality (p < 0.001; r = 0.454). However, no significant correlation was found in the humeral and tibial groups. Moreover, the sensitivity and specificity of the lengthening rate for obtaining good morphological quality callus were 72% and 80%, respectively, with an optimum diagnostic cutoff value of 0.976 mm/day for femoral lengthening. Conclusions: A higher-rate good morphological callus was obtained in femoral lengthening compared with tibia and humerus in patients with achondroplasia.

The "butterfly" suture technique for meniscal repair.

One of the important factors effecting meniscal healing is the strength of primary fixation obtained by repairing technique. From this perspective, it is important to choose the technique ensuring a higher primary fixation strength for meniscal repairs. We described a new technique for meniscal repair called "butterfly" technique using Viper device and hypothesized that high primary fixation strength can be obtained with this technique. The study was performed on calve knees. Full-thickness longitudinal tears 2 cm in length and 3 mm medial from the periphery were created in corpora of medial menisci of 14 calves. After creating tears, menisci were divided into two equal groups. In Group 1, two vertical loop sutures 1 cm apart were placed using a Viper device. Whereas in Group 2, tears were repaired using "butterfly" sutures. The mean load to failure was 156.3 ± 13.1 and 186 ± 15.8 N in Group 1 and 2, respectively (p = 0.002). The fixation strength in Group 2 was significantly higher than in Group 1. We suggest that, using Viper device and all-inside "butterfly" suturing techniques, meniscal ruptures with appropriate locations can be repaired with higher primary fixation strength.

The Effect of Intraarticular Insulin on Chondral Defect Repair.

OBJECTIVE: The aim of this study is to evaluate the effects of intraarticular insulin on the treatment of chondral defects. DESIGN: Twenty-four mature New Zealand rabbits were randomly divided into 3 groups as control (Group 1), microfracture (Group 2), and microfracture and insulin (Group 3). Four-millimeter full-thickness cartilage defects were created to the weight-bearing surface on the medial femoral condyles of each rabbit. In the first group, any additional interventions were not performed. Microfracture was performed on defects in groups 2 and 3. Additionally, 10 IU of insulin glargine was administrated into the knee joints of the third group. Three months after surgery, the knee joints were harvested and cartilage quality was assessed according to Wakitani and ICRS (International Cartilage Repair Society) scores histopathologically. Insulin injections were performed into the knees of 2 additional rabbits without creating a cartilage defect to evaluate the potential adverse effects of insulin on healthy cartilage (Group 4). RESULTS: The total ICRS and Wakitani scores of the insulin group were found to be significantly lower than the microfracture group but similar to the control group. No negative effects of insulin on healthy cartilage were detected. Intraarticular insulin after surgery has led to a statistically significant decrease in systemic blood sugar levels whereas the decrease observed after administration to intact tissues was not statistically significant. CONCLUSIONS: Insulin had a negative influence on the quality of cartilage regeneration and had no effect on healthy cartilage. Intraarticular insulin administration does not cause significant systemic effects in intact tissue.

Effects of Collagen- and Arginine-Fortified Osteokine Supplementation on Fracture Healing.

Introduction Delayed union or nonunion is an important clinical challenge for orthopedic surgeons. In addition to the main treatment algorithms, the use of nutritional supplements is increasingly common. In this study, we investigated the effects of nutritional supplements fortified with arginine and collagen on fracture healing. Materials and methods Twenty-four rats with femur fractures were divided into experimental and control groups. Intramedullary fixation was performed in both groups. 20 ml/kg nutritional supplement was given to the experimental group. Radiological examination was performed at third and sixth weeks, and histopathological examination was performed at the sixth week. Results No statistically significant difference was found between the radiological scores of the groups at the third and sixth weeks. Nutritional supplement affected the histological properties of callus. Histological evidence of bone healing was observed by the sixth week in both groups but the score was higher in nutritional supplement group. A statistically significant difference was found between the histopathological scores of the groups at the sixth week. Conclusion Arginine- and type two collagen-augmented traditional nutritional supplements may help to achieve more successful results in fracture healing.

First order colossal magnetoresistance transitions in the two-orbital model for manganites.

Large-scale Monte Carlo simulation results for the two-orbital model for manganites, including Jahn-Teller lattice distortions, are presented here. At hole density x=1/4 and in the vicinity of the region of competition between the ferromagnetic metallic and spin-charge-orbital ordered insulating phases, the colossal magnetoresistance (CMR) phenomenon is observed with a magnetoresistance ratio ∼10,000%. Our main result is that this CMR transition is found to be of first order in some portions of the phase diagram, in agreement with early results from neutron scattering, specific heat, and magnetization, thus solving a notorious discrepancy between experiments and previous theoretical studies. The first order characteristics of the transition survive, and are actually enhanced, when weak quenched disorder is introduced.