Osteotomy Angle Research Articles

An animal experimental study on domestic robot-assisted total knee arthroplasty

To evaluate the performance, safety, and precision of the Yuanhua robotic-assisted total knee arthroplasty system (YUANHUA-TKA) through animal experiments, which will provide reference data for human clinical trials. Six 18-month-old goats, weighing 30-35 kg, were used in this study. The experimental study was divided into two parts: the preoperative planning and intraoperative bone resection. CT scans of the goats' lower extremities were firstly performed before the experiments. Then the CT scans were segmented to generate the femoral and tibial three-dimensional (3D) models in the YUANHUA-TKA system. The volumes and angles of each resection plane on the femur and tibia were planned. The bone resection was finally implemented under the assistance of the YUANHUA-TKA system. After completing all bone resections, the lower extremities of each goat were taken to have CT scans. By comparing the femoral and tibial 3D models before and after the experiments, the actual bone resection volumes and angles were calculated and compared with the preoperative values. During the experiments, no abnormal bleeding was found; the YUANHUA-TKA system ran smoothly and stably and was able to stop moving and keep the osteotomy in the safe zone all the time. After the experiment, the resection planes were observed immediately and found to be quite flat. There was no significant difference between the planned and actual osteotomy thickness and osteotomy angle ( P>0.05); the error of the osteotomy thickness was less than 1 mm, and the error of the osteotomy angle was less than 2°. The YUANHUA-TKA system can assist the surgeons to perform osteotomy following the planned thickness and angle values. It is expected to assist surgeons to implement more accurate and efficient osteotomy in the future clinical applications.

Anatomical Study of the Cuboid and Its Ligamentous Attachments and Its Implications for a Cuboid Osteotomy.

Background:Lateral column lengthening (LCL) for flexible flatfoot is an effective surgery with powerful correction of deformity because it tightens only the lateral third of the long plantar ligament (LPL). However, LCL has been associated with joint damage at the osteotomy site and loss of foot flexibility owing to joint fixation. We focused on the cuboid and investigate a novel anatomical LCL osteotomy site that effectively tightens the LPL without damaging any joints.Methods:We studied 24 feet of 12 cadavers (mean age, 80.8 years). The lengths of the LPL and short plantar ligament, locations of the attachments, and shape and location of the cuneocuboid joint on the medial side of the cuboid were studied. ImageJ software was used to measure the osteotomy angle.Results:The lateral cuboid attachment of the LPL on average was located 4.6 mm from the calcaneocuboid joint, and the cuneocuboid joint on average was located 6.7 mm from the cuboid-metatarsal joint on the medial surface of the cuboid. The direct line connecting the anterior cuneocuboid joint and the oblique crest of the cuboid on average was at a 10.3-degree inclination posterior to the cuboid-metatarsal joint.Conclusion:A straight line must be selected between a point 4 mm from the calcaneocuboid joint laterally and 6 mm from the cuboid-metatarsal joint medially at a 10-degree posterior tilt to the cuboid-metatarsal joint to perform a cuboid osteotomy LCL without damaging the articular surface.Clinical Relevance:We investigated a potential novel cuboid osteotomy method for LCL.

The Radiographic Support for Distal Tibia Medial Opening-Wedge Osteotomy with Fibular Valgization Osteotomy for Medial Ankle Osteoarthritis

Category:Ankle; Ankle ArthritisIntroduction/Purpose:Supramalleolar osteotomy (SMO) has recently been accepted as the major surgical option for treating painful asymmetric ankle arthritis. The effectivenss of additional fibular valgization osteotomy during SMO procedure is still controversial. This study aimed to evaluate radiological and clinical outcomes of medial compartment ankle osteoarthritis (OA) after SMO with fibular valgization osteotomy. Also, the study is aimed to describe the radiographic support for the SMO with additional fibular osteotomy in relieving the medial ankle pain.Methods:The study is based on 45 cases of medial compartment ankle arthritis (43 patients) with moderate to severe medial ankle pain (at least 1-year follow-up). SMO and fibular valgization oblique osteotomy was performed concomitantly in 37 ankles (82.2%). As for the functional evaluation, visual analogue scale (VAS) pain scores, American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot scores and patient satisfaction were evaluated. On radiographs, tibial anterior surface angles (TAS), tibial lateral surface angles (TLS), and talar tilt angles (TT) were measured and the severity of ankle OA was classified by the Takakura stage. The evaluation of the effect of fibular valgization osteotomy entailed a comparison of new radiological measurement (medial clear space gap distance and talus center migaration distance) between two groups: Group 1 (with 37 cases of SMO with fibular valgization osteotomy) and Group 2 (with 8 cases of SMO without fibular valgization osteotomy).Results:The mean VAS pain score decreased from preoperative 6.5 to postoperative 1.3, and AOFAS score significantly improved from preoperative 60.4 to 88.3 at final follow-up. 91 percent (41 ankles) of the patients were satisfied with surgery. Mean TAS improved from preoperative 83.8° to postoperative 94.9° and TLS from 78.5° to 82.0°. 23 of 30 Takakura stage IIIa cases (77%) and 3 of 7 stage IIIb cases (42%) improved to stage II after SMO at final follow-up. Mean fibular valgization osteotomy angle was 12.4°. Medial gutter space gap distance improved from preoperative 0.7mm to postoperative 2.10mm. Talus center migration distance improved from -0.53mm to 2.03mm. Both radiologic parameters showed statistically significant differences between two groups, but there was no correlation between radiologic parameters and clinical outcomes.Conclusion:SMO for the patients with painful medial compartment ankle OA achieved favorable clinical and radiological outcomes. Also, high patient satisfaction (91%) as well as the improvement of Takakura stage was observed. SMO with additional fibular valgization osteotomy yielded widening of medial gutter space and recovery of talus center. Therefore, additional fibular valgization osteotomy during SMO could be optimal surgical option for the recovery of normal ankle mechanical axis.

Sacrum osteotomy to change pelvic parameters: Surgical technique and 3D modeling

PurposeSome clinical situations, such as great sagittal imbalance, high-grade isthmic spondylolisthesis or sacral malunion could require a sacral osteotomy to decrease pelvic parameters, horizontalize the sacrum or correct sacral malunion. Here is described a novel technique to perform a sacral osteotomy to decrease pelvic parameters with a lumbo-pelvic construct, with first a sacral slope decrease, then a pelvic tilt decrease. MethodsSimulations have been performed using tridimensional reconstructions of the lumbar spine and pelvis, made from CT-scan images of a healthy individual. A cadaveric study has then been performed. Results3D modeling exhibited linear relationship between osteotomy angle and pelvic incidence correction, through multiple simulations with 1° increment. Cadaveric study demonstrated feasibility. ConclusionThis preliminary work shows that this technique is efficient to decrease pelvic parameters. A linear relationship has been exhibited between osteotomy angle and PI decrease, as per the following formula: osteotomy angle=PI change/0.84.

Effects of Osteotomy Angle on Tibial Angulation and Torsion During CORA-Based Leveling Osteotomy in Toy Breed Dogs: A Computer Modeling-Based Study

Effects of Osteotomy Angle on Tibial Angulation and Torsion During CORA-Based Leveling Osteotomy in Toy Breed Dogs: A Computer Modeling-Based Study

Stress distribution is susceptible to the angle of the osteotomy in the high oblique sagittal osteotomy (HOSO): biomechanical evaluation using finite element analyses

Aim This computational study aimed to evaluate the influence of the angle of the osteotomy when performing a high oblique sagittal osteotomy over the distribution of stress to the osteosynthesis plates and mandibular segments. Material and methods: For this purpose, a finite element analysis of different combinations was carried out based on the osteotomy angle and mandibular mobilization using Autodesk Inventor® resulting in a total of 72 simulations. To check the correlation between the osteotomy angles with respect to the tension in the mandibular structure in different mobilizations, a student t-test was used. Results: The results of the advancement mobilizations (2.5 mm to 5.5 mm) reported increasing values for tension in the probe of the fourth screw and in the probe of the plate surface as the osteotomy angle increased (p-value <10-8). The results of the setback mobilizations (−2.5 mm to −5.5 mm) show comparable values (p-value <10-8). The resulting contact surface between bone segments varies depending on the osteotomy angle, increasing 44.67% from 45° to 70° and decreasing 22.05% when the angle is reduced to 30°. Conclusion: The angle of the osteotomy is a very relevant parameter in the design of the studied mandibular osteotomy, since the distribution of the reported stresses is substantially susceptible to its variation.

An In-House Computer-Aided Design and Computer-Aided Manufacturing Workflow for Maxillofacial Free Flap Reconstruction is Associated With a Low Cost and High Accuracy

In-house computer-aided surgical design and computer-aided manufacturing (CAD/CAM) can be used in oral and maxillofacial surgery for virtual surgical planning and 3-dimensional printing of patient-specific models. The purpose of this study was to measure the cost and accuracy of an in-house CAD/CAM workflow for maxillofacial free flap reconstruction. A retrospective cohort study of patients undergoing mandibular resection and free flap reconstruction was performed between July 2017 and March 2018 in which in-house CAD/CAM was used. The predictor variable was the in-house CAD/CAM workflow. The outcome variables were in-house workflow cost, as measured by the material expenses, and accuracy, as measured by comparative distance, osteotomy angle, and surfaced overlay measurements and the root mean square (RMS) between the preoperative virtual reconstructive plan and the postoperative computed tomography scan. Additional variables evaluated were time required for in-house CAD/CAM workflow, and clinical and radiographic outcomes. In-house CAD/CAM was used for 26 patients undergoing mandibular resection for benign or malignant disease and free flap reconstruction with fibula (n=24) or scapula free flap (n=2). Overall flap success rate was 95%. The mean in-house workflow cost per case was $3.87 USD. There were no significant differences between the mean comparative distance and osteotomy angle measurements between the planned and actual mandibular reconstructions with an RMS ranging from 5.11 to 9.00mm for distance measurements and 17.41° for the osteotomy angle measurements. The mean surface overlay difference was 1.90mm with an RMS of 3.72mm. The in-house CAD/CAM workflow is a low cost and accurate option for maxillofacial free flap reconstruction. The in-house workflow should be considered as an alternative to current practices using proprietary systems in select cases.

The clinical significance of osteotomy angle prediction for sagittal alignment reconstruction

As an effective way to reconstruct the spinal alignment, osteotomy has been widely used to reconstruct the sagittal alignment of spine and achieved significant results.In order to avoid the secondary sagittal disequilibrium caused by the inaccurate osteotomy angle, it is very important to make an appropriate operation plan before the operation and evaluate the osteotomy angle accurately.At present, scholars have proposed different targets for sagittal reconstruction of the spine with different patients and diseases.They also proposed various prediction methods of osteotomy angle according to different reconstruction standards and principles, as well as the selection of osteotomy sites and methods.In this paper, the preoperative evaluation of the osteotomy angle was reviewed in terms of the target of sagittal reconstruction, the prediction of osteotomy angle and the selection of osteotomy method and osteotomy site.

Accuracy of Correction and Postoperative Complications Associated with a PEEK Opening Wedge High Tibial Osteotomy Implant

Objectives:To evaluate the accuracy of correction angle of an all-PEEK medial opening wedge high tibial osteotomy (HTO) system, as well as determine the effect of correction angle on postoperative complications.Methods:Retrospective review was performed on patients who underwent an HTO by the senior author using an all-PEEK HTO system between 2014-2018 with a >6-month follow-up were included. Measurements were performed and classifications formulated by three senior residents and the senior author. Lateral hinge fractures (LHF) were classified according to Takeuchi classification system. Bivariate statistics were performed.Results:Thirty HTOs in 27 patients were included (50% female; age, 37.8±10.8 years). Average follow-up was 16.2±10.1 months. Average post-operative radiographic valgus correction (Δ, 5.8±2.4°) was significantly less than that of the average implant correction angle (8.1±2.3°; p<0.001), indicating an overall average under-correction of 2.3±2.1°. There were 5 failures (16.7%; defined as approximately >5° loss of planned correction) that shared a common mechanism of medial cortical failure inferior to the implant. When selecting out the construct failures, the average correction accuracy of the 25 (83.3%) non-failures (1.5±1.2°) was significantly better than the 5 (16.7%) failures (6.3±1.8°; p=0.002). Four fractures (13.3%) were identified: 3 (10%) Takeuchi type I and 1 (3.3%) type III. All type I fractures were associated with >5° planned correction loss with medial cortex buckling. Overall, 9 knees (30%) experienced minor complications: neuropathy (n=1; 3.3%), deep vein thrombosis (n=2; 6.7%), and superficial infection (n=3; 10%).Conclusion:The use of an all-PEEK medial opening wedge HTO implant is a safe and effective system, with an acceptable average under-correction of 1.5° in patients not sustaining medial cortex failure. Loss of correction was associated with medial cortex failure and Takeuchi type I LHF. This is the first description of this failure mechanism (medial cortex buckling) that is specific to this implant and technique.

Augmented reality guided osteotomy in hallux Valgus correction

BackgroundAn optimal osteotomy angle avoids shortening of the first metatarsal bone after hallux valgus surgery and therefore reduces the risk of transfer-metatarsalgia. The purpose of the present ex-vivo study was to investigate whether augmented reality (AR) would improve accuracy of the distal osteotomy during hallux valgus surgery.MethodsDistal osteotomies of the first metatarsals were performed on a foot model by two surgeons with different levels of surgical experience each with (AR, n = 15 × 2) or without (controls, n = 15 × 2) overlay of a hologram depicting an angle of osteotomy perpendicular to the second metatarsal. Subsequently, the deviation of the osteotomy angle in the transverse plane was analyzed.ResultsOverall, AR decreased the extent of deviation and the AR guided osteotomies were more accurate (4.9 ± 4.2°) compared to the freehand cuts (6.7 ± 6.1°) by tendency (p = 0.2). However, while the inexperienced surgeon performed more accurate osteotomies with AR with a mean angle of 6.4 ± 3.5° compared to freehand 10.5 ± 5.5° (p = 0.02), no significant difference was noticed for the experienced surgeon with an osteotomy angle of around 3° in both cases.ConclusionThis pilot-study suggests that AR guided osteotomies can potentially improve accuracy during hallux valgus correction, particularly for less experienced surgeons.

Comparison and Validation of Preoperative Planning Techniques for Distal Femoral Osteotomies and Proximal Tibial Osteotomies

Preoperative planning is important for accurate intraoperative execution in many surgical fields. Planning for distal femoral osteotomies (DFOs) and proximal tibial osteotomies (PTOs) consists of choosing the level of the osteotomy, measuring the angle of the osteotomy based on hip-knee-ankle alignment, and choosing a proper osteotomy wedge size. Medical imaging IT solutions company Sectra has implemented a new osteotomy tool in their radiographic system that is simpler than the accepted standard of modified center of rotation of angulation (mCORA) technique, yet unvalidated. In this study, we aim to compare the Sectra osteotomy tool versus the mCORA technique to measure the osteotomy angles as well as wedge sizes in both DFOs and PTOs to validate this new tool.We enrolled n = 30 consecutive patients with DFOs and n = 30 PTOs from the last year. The Pearson correlation coefficient (PCC) along with descriptive statistics was used to evaluate for similarity between the two techniques. We also compared interobserver and intraobserver reliability using intraclass correlation coefficients (ICC).The PCC for osteotomy angles in DFOs and PTOs were both 0.998 (p < 0.001 for both). For wedge sizes, the PCC in DFOs was 0.993 and 0.980 in PTOs (p < 0.001 for both). ICCs were high for both interobserver measurements in osteotomy angles and wedge sizes (range: 0.989-0.999) as well as intraobserver measurements (0.994-0.999).The Sectra osteotomy tool is a validated tool for preoperative measurements of DFOs and PTOs. It is reliable and simpler than the current practice of the mCORA technique. We suggest future studies to analyze this Sectra osteotomy tool in other settings as to incorporate it into widespread clinical use.

Simultaneous Surgery for Contouring the Prominent Zygoma and Mandibular Angles With Facelift in Middle-Aged Patients.

As the pursuit of higher self-attractiveness grows, an increasing number of middle-aged people are unsatisfied with their facial contour and required osteotomy. However, for these patients, performing osteotomy only would accelerate the aging process. Herein, the authors put forward simultaneous surgery for contouring the prominent zygoma and mandible with facelift for elderly patients. Patients were divided into 3 groups: group A with prominent mandible, group B with protruding zygoma, and group C with prominent mandible and zygoma. By implementing intraoral incision, outer cortex grinding, mandibular angle curved osteotomy, and reduction malarplasty were performed. Through facelift incision, the zygomatic arch was reduced and facelift was conducted. Patients were followed up for at least 12 months and were asked to evaluate their experience. From March 2009 to January 2018, a total of 55 patients received the surgery: 17 patients received mandibular angle osteotomy and facelift, 22 received malarplasty and facelift, and 16 underwent mandible and zygoma contouring and facelift. The recovery process was uneventful, with only 2 patients in group A and 1 patient in group C who suffered from a hematoma, which relieved without surgical intervene. The postoperative images showed smoother facial contours. Patients were satisfied with surgical outcomes. Significant improvements were seen comparing pre- and postoperative photos. Conducting osteotomy and rhytidectomy concurrently results in smooth facial contour and youthful appearance which improves patients' self-image and contributes to high patients' satisfaction. With a low complication rate and no long-term complication, the surgery is safe to perform. Level IV, the case study.

Effectiveness of distal tibial osteotomy with distraction arthroplasty in varus ankle osteoarthritis

BackgroundIn highly active older individuals, end-stage ankle osteoarthritis has traditionally been treated using tibiotalar arthrodesis, which provides considerable pain relief. However, there is a loss of ankle joint movement and a risk of future arthrosis in the adjacent joints. Distraction arthroplasty is a simple method that allows joint cartilage repair; however, the results are currently mixed, with some reports showing improved pain scores and others showing no improvement. Distal tibial osteotomy (DTO) without fibular osteotomy is a type of joint preservation surgery that has garnered attention in recent years. However, to our knowledge, there are no reports on DTO with joint distraction using a circular external fixator. Therefore, the purpose of this study was to examine the effect of DTO with joint distraction using a circular external fixator for treating ankle osteoarthritis.MethodsA total of 21 patients with medial ankle arthritis were examined. Arthroscopic synovectomy and a microfracture procedure were performed, followed by angled osteotomy and correction of the distal tibia; the ankle joint was then stabilized after its condition improved. An external fixator was used in all patients, and joint distraction of approximately 5.8 mm was performed. All patients were allowed full weight-bearing walking immediately after surgery.ResultsThe anteroposterior and lateral mortise angle during weight-bearing, talar tilt angle, and anterior translation of the talus on ankle stress radiography were improved significantly (P < 0.05). Signal changes on magnetic resonance imaging also improved in all patients. Visual analog scale and American Orthopedic Foot & Ankle Society scores improved significantly (P < 0.05), and no severe complications were observed.ConclusionDTO with joint distraction may be useful as a joint-preserving surgery for medial ankle osteoarthritis in older patients with high levels of physical activity.Level of evidenceLevel IV, retrospective case series.

Fully Immersive Virtual Reality for Total Hip Arthroplasty: Objective Measurement of Skills and Transfer of Visuospatial Performance After a Competency-Based Simulation Curriculum.

Fully immersive virtual reality (VR) uses headsets to situate a surgeon in a virtual operating room to perform open surgical procedures. The aims of this study were to determine (1) if a VR curriculum for training residents to perform anterior approach total hip replacement (AA-THR) was feasible, (2) if VR enabled residents' performance to be measured objectively, and (3) if cognitive and motor skills that were learned with use of VR were transferred to the physical world. The performance of 32 orthopaedic residents (surgical postgraduate years [PGY]-1 through 4) with no prior experience with AA-THR was measured during 5 consecutive VR training and assessment sessions. Outcome measures were related to procedural sequence, efficiency of movement, duration of surgery, and visuospatial precision in acetabular component positioning and femoral neck osteotomy, and were compared with the performance of 4 expert hip surgeons to establish competency-based criteria. Pretraining and post-training assessments on dry bone models were used to assess the transfer of visuospatial skills from VR to the physical world. Residents progressively developed surgical skills in VR on a learning curve through repeated practice, plateauing, on average, after 4 sessions (4.1 ± 0.6 hours); they reached expert VR levels for 9 of 10 metrics (except femoral osteotomy angle). Procedural errors were reduced by 79%, assistive prompts were reduced by 70%, and procedural duration was reduced by 28%. Dominant and nondominant hand movements were reduced by 35% and 36%, respectively, and head movement was reduced by 44%. Femoral osteotomy was performed more accurately, and acetabular implant orientation improved in VR assessments. In the physical world assessments, experts were more accurate than residents prior to simulation, but were matched by residents after simulation for all of the metrics except femoral osteotomy angle. The residents who performed best in VR were the most accurate in the physical world, while 2 residents were unable to achieve competence despite sustained practice. For novice surgeons learning AA-THR skills, fully immersive VR technology can objectively measure progress in the acquisition of surgical skills as measured by procedural sequence, efficiency of movement, and visuospatial accuracy. Skills learned in this environment are transferred to the physical environment.

Stability of lingual plate osteotomy in orthognathic surgery for patients with severe facial asymmetry: A retrospective analysis with 1-year follow-up

This study aimed to evaluate the stability of lingual plate osteotomy after sagittal split ramus osteotomy (SSRO) in patients with severe facial asymmetry. It included 20 patients undergoing lingual plate osteotomy between January 2011 and January 2017. Cephalometric X-ray imaging and three-dimensional computed tomography (3DCT) were performed before the operation and then 1 day and 1 year after the operation. The relapse rate and postoperative complications were assessed. The operation time was compared between lingual plate osteotomy and transoral angle osteotomy.Specific values measured on cephalometric X-ray and 3DCT images showed significant changes 1 day after the operation, with 47.9% correction occurring in the occlusal plane angle (mean ± SD = 1.74 ± 0.84°, p < 0.05). However, no significant differences were found between measurements taken 1 day and 1 year after the operation, with a 5% change seen in the occlusal plane angle (mean ± SD = 0.1 ± 0.24°, p = 0.61), suggesting that the surgical outcomes can be well maintained for at least 1 year after surgery.Three patients experienced numbness postoperatively but recovered within 1 year. The operation time for lingual plate osteotomy was shorter than that for transoral angle osteotomy. Our findings indicate that lingual plate osteotomy after SSRO is stable, effective, and safe in patients with severe facial asymmetry.

Innovative triangular cutting guide in cranial tibial wedge osteotomy in dogs with a cranial cruciate ligament rupture

Damage of the cranial cruciate ligament is a frequent cause of limb lameness in dogs. The aim of the study was to present the usefulness of a new guide for the blade of the oscillating saw in the Cranial Tibial Wedge Osteotomy (CTWO) technique. CTWO procedures using a proprietary triangular guide were performed on 62 dogs of both sexes. Radiological evaluation of the formation of bone scars in the Hammer scale showed that 3 months after the surgery most patients had a solid 2nd or 3rd degree of osteotomy consolidation. Lameness rating by the Functional Stifle Scale showed an improvement in the clinical condition of the dogs. This was reflected in the opinions of the owners expressed in Canine Brief Pain Inventory questionnaires, as presented in the chart. Values of the Pearson and Kendall correlation coefficients and statistical significance coefficients confirmed the relationship between the owners’ satisfaction and the results of the therapy and improvement in clinical trials. The triangular guide of the oscillating saw blade facilitates the transfer of the osteotomy angle determined on a digital radiogram onto the operating field, ensures precise orthogonal osteotomy incisions in the course of CTWO, significantly affects the time of callus formation, and accelerates the recovery of limb function.

The influence of different eating ways on the postoperative rehabilitation of female patients with the operation of mandibular angle osteotomy of inside oral cavity

Objective Researching the influence on patients with different eating ways after the operation of mandibular angle osteotomy of inside oral cavity. Method By using the method of convenience sampling, 50 patients were chosen who had operation of mandibular angle osteotomy of inside oral cavity in orthopedic surgery department of our hospital from January 2017 to December 2017 and the number was arranged according to the order of hospitalization. Patients with singular member were divided into the month feeding group (liquid diet were fed with the injection syringe which linked leather hose of 4-5cm after 6 hours awakening after general anesthesia in operation); patients with even number were divided into the nasal feeding group (stomach tube was put in the operation and nasal feeding was provided after 6 hours awakening after general anesthesia in operation and 5 hours after the operation). In every group, there were 25 patients. Observation scale which was made by themselves was used to evaluate the patients in the two groups and comparison for difference was made in the two groups, including weight change, wound drainage amount, oral wound secretion, the aspects of choke and cough, and the comfortable sensation of eating. Results For weight, in nasal feeding group, (2.19±0.48) kg were reduced and in month feeding group, (5.78±0.58) kg were reduced; the difference had the statistical significance (t=23.870, P 0.05). Conclusion The nasal feeding way can improve recovery level for patients after the operation of mandibular angle osteotomy of inside oral cavity and it is worthy of promotion in clinic application. Key words: Eating way; Inside oral cavity way; Mandibular angle osteotomy; Postoperative rehabilitation

Targeted endodontic microsurgery and endodontic microsurgery: a surgical simulation comparison.

To compare surgical time, bevel angle and site volumetric profiles of osteotomy and resection accomplished by targeted endodontic microsurgery (TEMS) and traditional endodontic microsurgery (EMS) in a surgical simulation model. An 80x80-mm cone beam computed tomography (CBCT) file was imported into Mimics software where artificial periapical lesions were created encompassing twelve root apices. Maxillary and mandibular models were 3D-printed. TEMS surgical guides were designed and 3D-printed for each surgical site. Three board-certified endodontists used the original CBCT to plan and perform EMS on models of six maxillary and six mandibular teeth. Next, the same endodontists performed TEMS on duplicate 3D-printed models for the same teeth. All surgeries were timed. Postoperative CBCT images of experimental models were made and imported into Amira software for measurement of bevel angle and site volumetric profiles. Paired t-tests compared the mean differences between EMS and TEMS groups. A Bonferroni correction determined data to be significant at P<0.004. TEMS significantly reduced surgical time (P<0.00001), had bevel angles more closely approaching zero degrees (P<0.01) and had significantly less volume of over-resection (P<0.001) and length of root resection (P<0.01). In this surgical simulation scenario, TEMS provided more efficient completion of osteotomy and resection, with a more appropriate root-end resection volume and bevel angle.

PO 18197 - PROMO technique for hallux valgus treatment

Introduction: Hallux valgus (HV) deformity is a prevalent condition that affects several aspects of the foot, causing pain, imbalance, immobility and increased risk of falls. Various osteotomies have been described for HV treatment, and osteotomy is the best option currently available among hundreds of surgical techniques, although no osteotomy is considered better than any other. The incidence of complications is associated with the degree of deformity, which may be defined according to the HV angle, the intermetatarsal angle and the degree of sesamoid subluxation. When the deformity is diagnosed as severe, the risk of recurrence is higher. Wagner et al. (2017) focused on controlling these complex cases and described a technique called Proximal ROtational Metatarsal Osteotomy (PROMO), inspired by the rotational osteotomy for Blount’s disease. Objective: To present the outcomes of 10 cases of severe HV (16 feet) treated using the PROMO technique. Methods: The pre- and postoperative data of 16 consecutive patients treated at a private hospital in São Paulo, SP, were collected. All patients were treated using the PROMO technique described by Wagner et al., and radiographs were taken to measure the parameters and collect records. A calculator programed in Microsoft Excel®, together with a cell phone application, were used to calculate the target angle correction power and osteotomy angle according to a process is described in this study. Results: There was satisfactory improvement in the American Orthopedic Foot and Ankle Society (AOFAS) score and subjective pain in all cases, in addition to a clear resolution of the deformity on physical examination and on radiographs. The union time; complications, such as symptomatic or asymptomatic pseudarthrosis; and angle correction power are also described in the present study. Conclusion: The PROMO technique is a safe and interesting option for the treatment of severe HV that has low rates of complications and a high angle correction power.

Measurement of proximal tibial morphology in northeast Chinese population based on three-dimensional reconstruction computer tomography.

Tibial component of total knee arthroplasty (TKA) is designed according to morphology of proximal tibia to a large extent. Owing to racial difference, current design of tibial component based on Caucasian may not be suitable for Chinese patients. Meanwhile, data of proximal tibial morphology in Chinese population is lacking. The objective of this research was to investigate proximal tibial morphology of northeast Chinese population.Computer tomography (CT) image of 164 northeast Chinese participants was collected. After three-dimensional (3D) reconstruction, size of tibia plateau and TKA resected surface were gauged to guide the design of TKA tibia prothesis in northeast Chinese population. Measurement of tibial size mainly includes tibial mediolateral length (tML), tibial medial/lateral anteroposterior length (tMAP and tLAP). Afterwards, tML/tAP ratio of tibia plateau and TKA resected surface were calculated as feature point of tibia prothesis. tMAP/tLAP ratio of TKA resected surface was calculated to represent tibial asymmetry degree. Medial and lateral posterior tibial slope (MPTS and LPTS) were also measured to give reference to posterior angle of tibia prothesis and angle of tibia osteotomy in TKA. Independent sample t test was performed to conduct statistical analysis, P < .05 was regarded as statistically significance.Northeast Chinese male has larger knee size than female. Significant difference of tML/tAP ratio was also observed between male and female on tibia plateau (1.71 ± 0.07 vs 1.77 ± 0.09) but not on TKA resected surface (1.60 ± 0.05 versus 1.61 ± 0.06). Significant difference of tMAP/tLAP ratio between male and female was also found and they were 1.31 ± 1.03 and 1.11 ± 0.05 respectively. Northeast Chinese female has higher PTS than male (MPTS: 9.56 ± 2.96° vs 8.81 ± 2.87° and LPTS: 8.57 ± 3.19° vs 8.44 ± 2.76°).Significant gender-difference of tibial size and asymmetry degree of tibial resected surface were found between northeast Chinese male and female. Meanwhile, northeast Chinese population has smaller knee size, larger PTS and tML/tAP ratio than that of Caucasian population. Therefore, Chinese-specific and gender-specific tibial prostheses were strongly recommended to be designed.