Stability Of Osteotomy Research Articles

Stability of osteotomy in minimally invasive hallux valgus surgery with "8" shaped bandage during gait: a finite element analysis.

Hallux valgus, a common foot deformity, often necessitates surgical intervention. This study evaluates the biomechanical alterations in patients post-surgery, focusing on the efficacy of an "8" bandage fixation system to promote optimal recovery. A three-dimensional (3D) model was constructed using CT data from a patient with hallux valgus. A quasi-static finite element analysis (FEA) was conducted in conjunction with gait analysis to evaluate the biomechanical changes at the osteotomy site under "8" shaped bandage fixation following hallux valgus surgery. The effects of the "8" shaped bandage on the stability of the osteotomy site and bone healing were investigated at three load points during the gait cycle. During the Loading Response (LR), Midstance (MSt), and Terminal stance TSt phases, the osteotomy end experienced maximum Von Mises stresses of 0.118, 1.349, and 1.485MPa, respectively. Correspondingly, the maximum principal stresses, all of which were compressive along the Z-axis, were 0.11662N, 1.39266N, and 1.46762N, respectively. Additionally, these phases showed a maximum relative total displacement of 0.848mm and a maximum relative shear displacement of 0.872mm. During the stance phase, the osteotomy end of the first metatarsal is predominantly subjected to compressive stress, with the relative displacement within the safe range to promote healing. The application of an "8" bandage for external fixation after surgery can maintain the dynamic stability of osteotomy sites post-minimally invasive hallux valgus correction during the gait cycle, thereby promoting the healing of the osteotomy ends.

Radiographic and complication evaluation of 2 different bioresorbable pins in hallux valgus corrective surgery.

Osteotomies to correct hallux valgus are usually secured using metal implants. Their main disadvantage is the need for a repeat surgery for removal of implanted material. Bioresorbable implants would make it possible to overcome this complication. Few studies analyse the results of using bioresorbable pins. The primary objective of this study is to compare hallux valgus correction radiographic results with the use of two types of bioresorbable pins. The secondary objectives are to screen for possible complications related to the use of these bioresorbable pins. This is a descriptive, retrospective, single-centre study carried out between May 2018 and May 2022 in the orthopaedic surgery department of the Centre Chirurgical Emile Gallé at the CHRU in Nancy (France). The study involved 105 hallux valgus (98 patients) operated on by open double metatarsal and phalangeal osteotomy. Osteotomies were stabilised with resorbable polylactic acid (PLLA) pins (Arthrex® TRIM-IT® drill pin) in 57 cases (53 patients), and with resorbable polylactic acid-polyglycolic acid copolymer (PGLA) pins (Bioretec® ActivaPins®) in 48 cases (45 patients). The efficacy of hallux valgus correction was analysed in terms of changes in preoperative and postoperative radiographic parameters at 1 and 6 months on a weight-bearing foot. Descriptive statistics were used to describe the demographic and radiological parameters of each group. The mean age was 59.7 years (range 25-81 years) in the PLLA group and 56 years (range 23-78 years) in the PGLA group. The mean preoperative HVA was 30° (range 15-63°) in the PLLA group and 30.8° (range 15-57°) in the PGLA group. The mean preoperative IMA was 14.4° (range 7-30°) in the PLLA group and 13.8° (range 7-20°) in the PGLA group. There was a statistically significant correction of hallux valgus in the PLLA (p=5.24 X 10-15 ) and PGLA (p=3.56 X 10-13 ) groups. The mean correction for the hallux valgus angle was 13° in the PLLA group and 12° in the PGLA group. There was no statistically significant difference in hallux valgus correction between the PLLA and PGLA groups, particularly in terms of hallux valgus severity. There was no radiological or clinical complication in the groups related to bioresorbable pins. The use of bioresorbable pins allows effective stabilisation of osteotomies to correct hallux valgus. There was no significant difference in correction between PLLA and PGLA implants, regardless of the severity of the hallux valgus. We did not observe any obvious clinical or radiological complications related to their use. The use of bioresorbable osteosynthesis material in forefoot surgery seems to offer interesting advantages, providing patients with safer and less invasive treatment solutions.

Effect of Plate Configuration in the Primary Stability of Osteotomies and Biological Reconstructions of Femoral Defects: Finite-Element Study.

Osteosynthesis is an alternative treatment for stabilizing femur-bone traumas. The initial stability of the fixation systems is one of the biomechanical parameters affecting implant failure and bone union, especially in surgeries of intercalary reconstructions after the removal of bone tumors. This study aimed to investigate the initial biomechanical effect of using one or two osteosynthesis plate configurations for femoral fixation and the effect of fastening the allograft to the osteosynthesis plate in the case of femoral allograft reconstructions. Three finite-element models of a femur with three different fixation conditions for a transverse osteotomy in the middle of the diaphysis, i.e., using one and two osteosynthesis plates and an intercalary allograft, were constructed. An eight-hole compression plate and a six-hole second plate were used to simulate osteosynthesis plates. The plate screws were tightened previously to the loading, and the tightening sequences simulate the bolt-tightening procedure in a surgical environment. The models were imported into the ADINA System for nonlinear analysis, using compression loads applied over the femur head. Models with the dual fixation systems had the most outstanding compression stiffness. The femur head movement in the dual plate system was 24.8% smaller than in the single plate system. A statistical analysis of a region of interest (VOI) placed in the femur diaphysis showed that the biomechanical effect of using the dual plate system is smaller in the osteotomy region than at the femur head, e.g., a displacement average decrease of only 5% between the two systems, while the maximum value decreases by 26.8%. The allograft fixation to the second osteosynthesis plate leads to an improvement in the system stability. The results presented in this work show that including the bolt analysis in the femoral diaphysis osteotomy fixation will allow for capturing the nonlinear behavior of the osteotomy region more realistically. The stability of the intercalary reconstruction of the femoral diaphysis was higher when the allograft was fastened to the second osteosynthesis plate.

Stabilizing a Femur Osteotomy with a Plate Fixation in Ambystoma mexicanum.

The axolotl (Ambystoma mexicanum) is a promising model organism for regenerative medicine due to its remarkable ability to regenerate lost or damaged organs, including limbs, brain, heart, tail, and others. Studies on axolotl shed light on cellular and molecular pathways ruling progenitor activation and tissue restoration after injury. This knowledge can be applied to facilitate the healing of regeneration-incompetent injuries, such as bone non-union. In the current protocol, the femur osteotomy stabilization using an internal plate fixation system is described. The procedure was adapted for use in aquatic animals (axolotl, Ambystoma mexicanum). ≥20 cm snout-to-tail tip axolotls with fully ossified, mouse-size comparable femurs were used, and special attention was paid to the plate positioning and fixation, as well as to the postoperative care. This surgical technique allows for standardized and stabilized bone fixation and could be useful for direct comparison to axolotl limb regeneration and analogous studies of bone healing across amphibians and mammals.

Stability of Proximal Femoral Osteotomies in Pediatric Bone Models Fixed with Flexible Intramedullary Nails and Evaluated by the Finite Element Method.

Objective To evaluate the stability of osteotomies created in the subtrochanteric and trochanteric regions in a pediatric femur model fixed by flexible intramedullary rods. Method Tomographic sections were obtained from a pediatric femur model with two elastic titanium rods and converted to a three-dimensional model. This model created a mesh with tetrahedral elements according to the finite element method. Three virtual models were obtained, and osteotomies were performed in different regions: mediodiaphyseal, subtrochanteric, and trochanteric. A vertical load of 85N was applied to the top of the femoral head, obtaining the displacements, the maximum and minimum main stress, and the equivalent Von Mises stress on the implant. Results With the applied load, displacements were observed at the osteotomy site of 0.04 mm in the diaphyseal group, 0.5 mm in the subtrochanteric group, and 0.06 mm in the trochanteric group. The maximum stress in the diaphyseal, subtrochanteric, and trochanteric groups was 10.4 Pa, 7.52 Pa, and 26.4 Pa, respectively. That is around 40% higher in the trochanteric group in regards to the diaphyseal (control). The minimum stress of the bone was located in the inner cortical of the femur. The equivalent Von Mises stress on the implants occurred at osteotomy, with a maximum value of 27.6 Pa in the trochanteric group. Conclusion In both trochanteric and subtrochanteric osteotomies, fixation stability was often lower than in the diaphyseal model, suggesting that flexible intramedullary nails are not suitable implants for proximal femoral fixations.

Sixty Years of Innovation in Biomechanical Orthognathic Surgery: The State of the Art and Future Directions

Craniofacial surgery is proposed and performed for a variety of reasons, ranging from congenital or acquired malformations to emotional disorders and parafunctions of the masticatory, respiratory, auditory, and visual systems. Surgery of the mandible and its orthostatic repositioning is the most common of these corrections of craniofacial anomalies. Throughout the history of these procedures, various techniques have been proposed and perfected, but always with a high rate of minor and major complications. The recurrence rate of mandibular malposition is high, as is the temporary loss of facial sensitivity and motor skills. These outcomes are often related to the choice of surgical technique rather than the skill of the surgeon, which is considered to be one of the most important factors in the final outcome. Surgical techniques involving direct manipulation of the vascular-nervous bundles, such as bilateral sagittal split osteotomy, clearly present the possibility of major or minor complications. In this study, an orthognathic surgical technique, performed by the same team for over 40 years and now available through a 20-year postoperative patient follow-up study, is presented with a literature review relating it to biomechanical concepts and bone remodeling to analyze the evolution of orthognathic surgery since it became common practice to correct maxillofacial discrepancies. In this review, we also present a case report in which previous orthodontic treatment prepared a patient for surgical correction of mandibular bone discrepancy without the need for combined maxillary and/or genioplasty, and we describe the most commonly used techniques today, as well as their advantages and disadvantages. The combination of established concepts together promotes favorable stability of mandibular osteotomies, functional anatomical positioning of the temporomandibular joint, reduced risk of injury to the mandibular vasculo-nervous bundle, and good aesthetics with positive patient acceptance and no relapse, thus these are the objectives for proposing innovative treatments that combine the technologies available today.

Geometric Cuts by an Autonomous Laser Osteotome Increase Stability in Mandibular Reconstruction With Free Fibula Grafts: A Cadaver Study

BackgroundNon-union and plate exposure represent a major complication after mandibular reconstruction with free fibula flaps. These drawbacks may be resolved by geometric osteotomies increasing inter-segmental bone contact area and stability. PurposeThe aim of this study was to compare inter-segmental bone contact and stability of geometric osteotomies to straight osteotomies in mandibular reconstructions with free fibula grafts performed by robot-guided erbium-doped yttrium aluminum garnet laser osteotomy. Study design, setting, sampleThis cadaveric in-vitro study was performed on fresh frozen human skull and fibula specimens. CT-scans of all specimens were performed for virtual planning of mandibular resections and three-segment fibula reconstructions. The virtual planning was implemented in a Cold Ablation Robot-guided Laser Osteotome. Predictor/exposure/independent variableFor predictor variables straight and geometric puzzle-shaped osteotomies were designed at resection of the mandible and corresponding fibula reconstruction. Main outcome variablesThe primary outcome variable was the stability of the reconstructed mandible investigated by shearing tests. Moreover, secondary outcome variables were the duration of the laser osteotomies, the contact surface area and the accuracy of the reconstruction, both evaluated on post-surgical CT-scans. CovariatesCovariables were not applicable AnalysisData were reported as mean values (± standard deviation) and were statistically analyzed using an independent-sample t-test on a significance level of α = 0.05. Root mean square deviation was tested for accuracy. Results8 skulls and 16 fibula specimens were used for the study. 112 successful laser osteotomies (96 straight and 16 geometrical) could be performed. Geometric osteotomies increased stability (110.2±36.2 N vs. 37.9±20.1N, p<0.001) compared to straight osteotomies. Geometric osteotomy of the fibula took longer than straight osteotomies (10.9±5.1min vs. 5.9±2.2min, p=0.028), but could provide larger contact surface (431.2±148.5mm2 vs. 226.1±50.8mm2, p=0.04).Heat map analysis revealed a mean deviation between preoperational planning and post-reconstructive CT-scan of -0.8 ±2.4mm and a root mean square deviation of 2,51mm. ConclusionMandibular resection and reconstruction by fibula grafts can accurately be performed by a cold ablation robot-guided laser osteotome without need for cutting guides. Osteotomy planning with geometric cuts offers higher stability and an increased bone contact area which may enhance healing of the reconstructed mandible.

Impact of the lateral skeletal stability following bilateral sagittal split ramus osteotomy for mandibular asymmetry

This study evaluated the stability of bilateral sagittal split ramus osteotomy (BSSRO) associated with positional plagiocephaly and temporal and masseter muscles using posteroanterior cephalogram analysis and three-dimensional computed tomography (3D-CT). This retrospective cohort study included 31 patients who underwent BSSRO for mandibular asymmetry. The cranial vault asymmetry index (CVAI) and the cephalic index were used as indicators of positional plagiocephaly. The distance from the vertical reference line to the menton (Me) was measured on posteroanterior cephalograms immediately and 1 year after surgery, and postoperative stability was assessed. Temporal and masseter muscles were constructed from 3D-CT data and their volumes were measured. Simple regression analysis showed a significant correlation between postoperative changes in the vertical reference line to the Me and the CVAI (R=0.56, p=0.001), the amount of surgical movement in the vertical reference line to the Me (R=0.41, p=0.023), and the variable temporal muscle volume (R=0.27, p=0.028). There was no significant correlation between postoperative changes in the vertical reference line to the Me and the cephalic index (R=0.093, p=0.62) and variable masseter muscle volume (R=0.16, p=0.38). According to multivariate analysis, CVAI (p=0.003) and amount of surgical movement in the vertical reference line to the Me (p=0.014) were significant predictors of postoperative change in the vertical reference line to the Me. Positional plagiocephaly and amount of surgical movement influence lateral skeletal stability following BSSRO for mandibular asymmetry.

Preliminary study on the stabilization of varus proximal femoral osteotomies using pediatric LCP plates in adults undergoing combined correction of proximal femoral and acetabular dysplasia.

Proximal femoral osteotomy (PFO) with periacetabular osteotomy (PAO) improves femoral head coverage in patients with proximal femoral and acetabular dysplasia. Historically, blade plates used in the PFO cause soft-tissue irritation and often lead to implant removal. Here we present a technique using a lower profile pediatric proximal femoral locking compression plate (LCP) for the PFO in a series of adults. The results from 13 hips in 11 patients ≥ 18years old (age 18-37) with > 10months of follow-up are presented. All patients had improved radiographic parameters, pain, and total Merle d'Aubigné-Postel scores postoperatively. Eleven hips (85%) had the LCP removed an average of 15.8 ± 8.6months postoperatively, often due to pain over the greater trochanter. The pediatric proximal femoral LCP is effective for PFO in combined PAO PFO procedures but has a high rate of lateral hip discomfort leading to implant removal.

Proximal bone block with distal screw trajectory improves mechanical stability during distalization tibial tubercle osteotomy.

The purpose of this study was to quantify differences in mechanical stability of a wedge-shaped distalization tibial tubercle osteotomy (TTO) with a standard technique, versus a modified technique with use of a proximal bone block and distally angled screw trajectory. Ten fresh-frozen cadaver lower extremity specimens (five matched pairs) were utilized. Within each specimen pair, one specimen was randomly assigned to undergo a standard distalization osteotomy fixed with two bicortical 4.5-mm screws oriented perpendicular to the long axis of the tibia, and the other to undergo a distalization osteotomy with modified fixation utilizing a proximal bone block and distally angled screw trajectory. Each specimen's patella and tibia were mounted on a servo-hydraulic load frame using custom fixtures (MTS Instron). The patellar tendon was dynamically loaded to 400 N at a rate of 200 N/second for 500 cycles. Following the cyclic loading, loading to failure was done at 25mm/min. The modified distalization TTO technique demonstrated significantly higher average load to failure compared to the standard distalization TTO technique (1339 N vs. 844.1 N, p < 0.001). Average maximum tibial tubercle displacement during cyclic loading was significantly smaller in the modified TTO technique group compared to the standard TTO technique (1.1mm vs. 4.7mm, p < 0.001). This study demonstrates that distalization TTO utilizing a modified technique with a proximal bone block and distally aimed screws is biomechanically superior to standard distalization TTO without proximal bone block and screw trajectory perpendicular to the long axis of the tibia. This increased stability may aid in reducing the reported higher complication rates (including loss of fixation, delayed union and nonunion) following distalization TTO, although future clinical outcome studies are warranted.

Long-term vertical stability of horseshoe osteotomy for the correction of large vertical excess of the maxilla, a retrospective assessment in 15 patients

IntroductionVertical stability after a Le Fort I (LF1) osteotomy with substantial upward movement can be compromised by the position and the volume of the inferior turbinate. A horseshoe (HS) osteotomy represents then an alternative as it preserves the hard palate and the intranasal volume. The aim of this study was to assess the vertical stability of the maxilla after HS osteotomy. Materials and methodsPatients who underwent a HS osteotomy for the correction of long-face syndrome were retrospectively analyzed. The vertical stability was assessed on lateral cephalograms performed preoperatively (T0), immediately postoperatively (T1), and at the last follow-up (T2) by studying points C (the distal cusp of the first maxillary molar), point P (the prosthion, the lowest edge of the maxillary alveolus of the central incisor), and point I (the upper central incisor edge) in a coordinate system. Postoperative complications and aesthetics of the smile were also investigated. ResultsFifteen patients were included (7 females, 8 males, mean age 25.5 ± 9.8 yeras). The mean impaction ranged from 5 mm on point P to 6.1 mm on point C, with a maximal movement of 9.5 mm. A non-significant relapse of 0.8 ± 1.7, 0.6 ± 0.8, and 0.5 ± 1.8 mm was observed after a mean 20.7 months on point C, P, and I respectively. Smile parameters were significantly improved by the procedure, mainly regarding the correction of the gum smile. ConclusionHS osteotomy represents a good alternative to total LF1 osteotomy for substantial maxillary upward movement in long face syndrome deformities.

What are the surgical risks and 2-year stability of mandibular anterior subapical osteotomy in the treatment of dentoalveolar protrusion?

To investigate the stability and complications of mandibular anterior subapical osteotomy (ASO) in the treatment of bimaxillary dentoalveolar protrusion by way of a retrospective study. One hundred and twenty patients who received orthognathic surgery at a single center between 2008 and 2017 were included. Relapse was assessed by serial tracings of lateral cephalograms which were obtained pre-operatively (T1), within 6weeks after surgery (T2) and at 2years after surgery. The changes between T2 and T3 represented stability and were tested using the paired t test. The relationship between the extents of surgical repositioning (T2-T1) and relapse (T3-T2) was investigated using the Pearson correlation coefficient. The associations between the variables and the occurrence of relapse and complications identified the risk factors and were evaluated using the χ2 test or Fisher's exact test. When r > 0.80, clinical correlation was considered significant; and statistical significance was set at P < 0.05, while confidence interval was set at 95%. There was a mean uprighting of L1-MP by 12.7°. At 2years after surgery, 96.7% of the patients experienced a mean relapse of L1-MP by 2.9°. The extent of surgical repositioning was only weakly correlated with that of relapse and no specific factor that increased the risk of relapse could be identified. The most frequent complications were blood loss requiring transfusion, wound dehiscence or infection, gingival recession, and periodontal bone loss, involving 25.8 to 43.3% of the patients. The remaining complications included tooth root damage, fixation hardware exposure or infection, lingual mucosal laceration, and tooth devitalization. There were no cases of avascular necrosis or nonunion. Although relapse occurred in most of the patients after 2years, the actual extent was small (2.9°) which was not likely to be clinically significant. HKUCTR-2964 CLINICAL RELEVANCE: Although ASO may be valuable in correcting mandibular dentoalveolar protrusion, the procedure brings with it risks and complications and should be reserved for severe deformities.

"In vitro" evaluation of bacterial biofilm formation on different cerclage systems.

Cerclage wiring may be used for fracture fixation or osteotomy stabilization in revision arthroplasty. There is a lack of evidence regarding the potential risk of bacterial colonization for the different types of cerclages. The objective of our research is to study the adhesion and biofilm formation of S. epidermidis, S. aureus, and P. aeruginosa on two different cerclage cable models, comparing a polymer cable and a stainless steel metal cable. A two-cm cerclage piece of each material was submerged in 2mL of tryptic soy broth (TSB) inoculated with 10μL of a 0.5 McFarland bacterial culture, and incubated at 37°C during 2h for adhesion and 48h for biofilm formation. The cerclages were washed with 1xPBS and sonicated in a new culture medium. Aliquots of several dilutions of each sonicated culture were spread in TSB agar and incubated at 37°C for 24h. The number of colonies was counted. The colony-forming units per ml (CFU/mL) and the percentage of reduction were calculated. Experiments were triplicated. For P. aeruginosa, a statistically significant reduction in biofilm formation was found on the polymer cerclage cable, compared to the metal cerclage cable. Reductions of 59% and 88%, after 2h and 48h, respectively, were observed. For S. epidermis and S. aureus, there was a trend towards lower bacterial adhesion and biofilm formation for the polymer cerclage cable. In summary, these results demonstrate that the braided polymer cerclage cable may be less prone to bacterial adherence and biofilm formation compared to the braided metal cerclage cable.

Undercorrection: the undesired effect of compression on the osteotomy gap of the medial opening wedge high tibial osteotomy and its clinical significance.

Undercorrection is a common problem in opening wedge high tibial osteotomy (OWHTO). We investigated the compression effect of cortex screw on the osteotomy gap and its clinical significance. A standard OWHTO using the TomoFix plate was conducted on 20 bone models in two groups to get a 10-mm medial osteotomy gap. A cortex screw was used temporarily in a neutral (at the center) and an eccentric position (near the inclined plane) of the dynamic hole in group 1 and group 2, respectively. The mean of undercorrection observed in the two groups was compared using an independent t test. Also, the effect of compression on the gap between the plate and medial tibial cortex, and the osteotomy gap was evaluated using a Sine rule. Besides, the mean undercorrection observed was assessed for clinical significance based on the effect on the weight-bearing axis (WBA) using a Cosine Rule. The mean undercorrection was 1.3 ± 0.6mm and 2.6 ± 0.6mm in group 1 and group 2, respectively. A significantly greater undercorrection was observed in group 2 (p < 0.001). The correction loss in group 2 has resulted from combinations of the sliding effect of the dynamic hole and oblique compression effect over the gap between the plate and medial tibial cortex whereas in group 1 it has only resulted from the oblique compression effect. The observed undercorrection in group 2 has resulted in clinically significant WBA shift (10%) over the width of the tibial plateau. In OWHTO, compression is important for the stability and healing of osteotomy, but it can also cause loss of correction. In patients requiring large correction, the surgeon should control the amount of compression required and consider making extra osteotomy gap to avoid undercorrection. Furthermore, the placement of cortex screws in neutral is essential to lower the risk of undercorrection.

Biomechanical Evaluation of a New Fixation Method for Stabilization of Sagittal Split Ramus Osteotomy After Mandibular Advancement

Study Design: Biomechanical in vitro study. Mandibular advancement after sagittal split ramus osteotomy (SSRO) is a common procedure in orthognathic surgery. Several fixation methods are used for stabilization of SSRO. Objective: The aim of this study was to compare a new fixation method (gridplate) with more contemporary applied methods of fixation. Material and Methods: In this study, 50 polyurethane hemimandibles with a prefabricated SSRO were used as specimens. All hemimandibles were advanced by 8 mm and divided into 5 groups with different fixation methods: (A) one 4-hole miniplate with 4 monocortical screws; (B) two 4-hole miniplates with 8 monocortical screws; (C) one 4-hole miniplate with 4 monocortical screws and 1 bicortical screw in the retromolar area (hybrid method); (D) 3 bicortical screws in an inverted-L pattern; and (E) one 8-hole gridplate with 8 monocortical screws. Loads in newtons were recorded at displacements of the mandibular incisive edge at 1 mm, 3 mm and 5 mm. Results: Fixation with 3 bicortical screws and the gridplate presented the most stability, followed by two 4-hole miniplates. Fixation with the hybrid method or the single miniplate showed the least stability. Conclusion: According to the results of this study, the 8-hole gridplate design appears a sufficient fixation method regarding stabilization of SSRO with larger mandibular advancement.

Calcaneal cuboid joint motion and osteotomy stability in children one year after calcaneal lengthening osteotomy

IntroductionFlexible pes planovalgus in children may be corrected with a calcaneal lengthening osteotomy (CLO).However, CLO surgery may displace the distal calcaneal fragment dorsally and affect the motion in the calcaneal-cuboid joint (CCJ). We used radiostereometric analysis (RSA) to evaluate CCJ motion and CLO stability in children one year after CLO. MethodsTen patients (10 feet) with symptomatic flexible pes planovalgus were investigated one year after CLO. Mean age was 11.5 years (range 8.2–14.2). Standardised RSA measurements of the foot were obtained one year after surgery without and with weight-bearing (single leg stance). Tantalum markers inserted during surgery, were used to described the CCJ motion as cuboid bone motion with respect to the distal calcaneus, and the CLO stability as distal calcaneal migration with respect to the proximal calcaneus. ResultsOne year after surgery the CLO was stable. The motion in the CCJ upon full weight-bearing was mean −1.04 mm (CI95% −1.40; −0.67) joint distraction, mean 2.27 mm (CI95% 1.57; 2.96) cuboid dorsal translation, mean −1.94 mm (CI 95% −2.68; −1.20) cuboid medial translation, and mean 7.43° (CI 95% 3.97; 10.88) adduction. ConclusionThe motion in the CCJ of children with CLO corrections for pes planovalgus is similar to that of adults during stance load with a normal foot posture and the patients were asymptomatic. Marker-based RSA may be used to evaluate causalities of foot symptoms after CLO surgery.

Biomechanical investigation of pelvic stability in developmental dysplasia of the hip: unilateral salter osteotomy versus one-stage bilateral salter osteotomy

BackgroundDevelopmental dysplasia of the hip (DDH) is a common disease in infants and children, and the treatment of bilateral DDH remains controversial. This study aimed to evaluate the stability of one-stage bilateral Salter pelvic osteotomy for bilateral DDH in patients of walking age.MethodsIn total, nine child cadavers aged 2–6 years were included. A universal mechanical testing machine was used for stability test. We performed two different surgical procedures on the specimens: nine child cadavers underwent unilateral Salter pelvic osteotomy, and six child cadavers were randomly selected to undergo Salter pelvic osteotomy again to simulate one-stage bilateral Salter pelvic osteotomy. The stability of the bilateral sacroiliac joints, local stability of the operation area, ultimate load test, and axial stiffness were evaluated.ResultsBoth unilateral and bilateral Salter osteotomy could destroy the integrity of the pelvic ring and increase the risk of pelvic instability. In this study, compared with unilateral Salter osteotomy, bilateral Salter osteotomy had similar pelvic stability, and there was no significant difference between unilateral and bilateral Salter osteotomy in sacroiliac joint stability (p > 0.05), local stability (p = 0.763), ultimate load (p = 0.328), and axial stiffness (p = 0.480).ConclusionsOne-stage bilateral Salter pelvic osteotomy as a potential surgical method is viable and stable for children with bilateral DDH.

Graft materials provide greater static strength to medial opening wedge high tibial osteotomy than when no graft is included

BackgroundThe purpose of this study was to compare the stability of medial opening-wedge high tibial osteotomy (MOWHTO) with and without different graft materials. Good clinical and radiological outcomes have been demonstrated when either using or not using graft materials during MOWHTO. Variations in the biomechanical properties of different graft types, regarding the stability they provide a MOWHTO, have not been previously investigated.MethodsA 10 mm biplanar MOWHTO was performed on 15 artificial sawbone tibiae, which were fixed using the Activmotion 2 plate. Five bones had OSferion60 wedges (synthetic group), five had allograft bone wedges (allograft group), and five had no wedges (control group) inserted into the osteotomy gap. Static compression was applied axially to each specimen until failure of the osteotomy. Ultimate load, horizontal and vertical displacements were measured and used to calculate construct stiffness and valgus malrotation of the tibial head.ResultsThe synthetic group failed at 6.3 kN, followed by the allograft group (6 kN), and the control group (4.5 kN). The most valgus malrotation of the tibial head was observed in the allograft group (2.6°). The synthetic group showed the highest stiffness at the medial side of the tibial head (9.54 kN·mm− 1), but the lowest stiffness at the lateral side (1.59 kN·mm-1). The allograft group showed high stiffness on the medial side of the tibial head (7.54 kN·mm− 1) as well as the highest stiffness on the lateral side (2.18 kN·mm− 1).ConclusionsThe use of graft materials in MOWHTO results in superior material properties compared to the use of no graft. The static strength of MOWHTO is highest when synthetic grafts are inserted into the osteotomy gap. Allograft wedges provide higher mechanical strength to a MOWHTO than when no graft used. In comparison to the synthetic grafts, allograft wedges result in the stiffness of the osteotomy being more similar at the medial and lateral cortices.

The preliminary report about the modified supramalleolar tibial osteotomy for asymmetric ankle osteoarthritis.

Supramalleolar tibial osteotomy (SMO) for asymmetric ankle osteoarthritis (OA) is known to lead to satisfactory. Here, authors present a preliminary report on SMO surgical treatment in patients with asymmetric ankle arthritis. We reviewed cases of asymmetric ankle OA treated by modified SMO between January 2011 and October 2015. Clinical assessment was performed with the use of the ankle and hindfoot score of the American Orthopedic Foot and Ankle Society (AOFAS), foot function index, and visual analogue scale (VAS). Patient satisfaction with surgery and postoperative subjective symptoms were examined. Radiographic evaluation included preoperative and postoperative tibial anterior surface angle (TAS angle), talar tilt angle (TT angle), and tibial lateral surface angle (TLS angle). Takakura stage was measured. The average follow-up period was 46.3 months. The AOFAS score was 55.7 ± 6.03 preoperatively and 76.0 ± 4.73 postoperatively. Foot function index was 60.7 ± 8.78 preoperatively and 30.8 ± 7.59 postoperatively. VAS was 7.2 ± 0.53 before surgery and 1.9 ± 0.85 after surgery. Clinical evaluations showed statistically significant improvement. The majority of patients reported satisfactory results in the subjective satisfaction evaluation. TAS angle was 84.6 ± 1.82 preoperatively and 94.0 ± 2.79 postoperatively. TLS angle was 78.8 ± 2.11 preoperatively and 81.8 ± 1.80 postoperatively. TT angle was 3.6 ± 1.26 before surgery and 2.1 ± 0.79 after surgery. Thirteen cases showed radiographic improvement of Takakura stage. Complications were not observed. Modified SMO is a useful procedure that provides for the union and stability of osteotomy with the advantages of the existing SMO and can be performed without bone graft.

Stabilization of chevron osteotomy with a capsuloperiosteal flap: Results in 15 years of follow-up.

Distal chevron osteotomy (DCO) is used more frequently than other methods for the correction of mild-to-moderate hallux valgus deformity because it is markedly more stable. Here, we evaluated the use of a capsuloperiosteal flap to stabilize DCO and presented our last longer follow-up. This study included a total of 57 patients (86 feet) made up of 50 women (79 feet) and 7 men (7 feet) with a mean age of 37.8 years who were diagnosed with hallux valgus and met the inclusion criteria. These patients received treatment using a capsuloperiosteal flap to stabilize DCO from 1994 to 2000. Clinical outcomes of the patients were assessed using the American Orthopaedic Foot and Ankle Society hallux scale. The mean follow-up duration was 14.8 years. The score increased from a preoperative mean of 52 points to a mean of 90.5 points at last follow-up. The mean hallux valgus angle changed from 30.3° preoperatively to 14.4° postoperatively at the last follow-up. The first to second intermetatarsal angle changed from 13.6° preoperatively to 10.5° postoperatively. The correction in the range of motion proved to be consistent with only an average of 1° correction loss and 5.5° loss. Eighty-four feet (97.6%) were pain-free. Discomfort with shoe wear was absent in 82 feet (95.3%) postoperatively, and 23 of 24 (95.8%) patients were fascinated cosmetically. Correction of mild-to-moderate hallux valgus deformity with the use of capsuloperiosteal flap for stabilization of DCO provided findings comparable with the literature regarding clinical and radiological outcomes at long-term follow-up. Level of Evidence: IV, Retrospective Case Series.