Osteotomy Design Research Articles

Split-Calvarial Bone Graft for a Large Calvarial Defect: Revealing Hidden Contours Through Virtual Surgery Planning

Virtual surgical planning (VSP) stands as a novel advancement in craniofacial surgery. Since its inception, VSP has had the ability to improve accuracy and consistency in craniofacial surgery. The current case report describes the use of VSP in the context of a pediatric growing skull fracture and large calvarial defect requiring autologous reconstruction. Emphasis is placed on patient-specific osteotomy design and cutting guide design to decrease risk and optimize surgical outcomes. This case report illustrates a unique application of VSP in craniofacial surgery.

Predicting the Future Focus of Orthognathic Surgery: Outcome-Driven Planning and Treatment With Function, Esthetics, and Occlusion as Key Indicators

As we reflect on the last 7decades since the first descriptions of modern orthognathic surgery (OGS) by Trauner and Obwegeser, we ponder what the next "game-changers" will be over the upcoming decades. We certainly recognize the prior contributions of Hullihen in 1849 and others in the 1920s and 1930s, and the pioneering work of Tessier, Obwegeser, and Bell in the 1960s and 1970s. Although there have been some changes in osteotomy design, as well as the landmark game-changing introduction of rigid internal fixation in the 1970s and 1980s, many of the more recent major changes have occurred only in the past decade or 2. The use of personalized and precision medicine with virtual surgical planning, and patient-specific implants has been transformational. Certainly, there will be more advances in the realm of diagnosis, surgical techniques and protocols, biomaterials and tissue engineering, and surgeon and patient education. But, as an international group of orthognathic surgeons, we believe that the most significant "next big thing" will be a clinical and research focus on patient-oriented outcomes and an improved quality of life. This will require outcome-driven planning and treatment with function, esthetics, and occlusion as key outcome indicators. Here we identify some shared visions and objectives for OGS with the aim to delineate future advancements to enhance the care of patients with dentofacial deformities. While we have organized the sections to cover key areas, the fundamental concepts include advances in these areas: diagnosis and treatment planning (eg, imaging, virtual surgical planning, artificial intelligence, and point-of-care workflows); materials development (eg, patient-specific implant, three-dimensional printing, tissue engineering, biodegradable implants, bone cements, titanium and magnesium implants, and developmental and regenerative medicine); and patient management (eg, minimally-invasive surgery, clear aligner therapy, temporary anchorage devices, outpatient OGS, age-centered treatment, and augmented reality/virtual reality).

Distractor position and distraction amplitude in fronto-facial monobloc advancement : A case series

Fronto-facial monobloc advancement with internal distraction (FFMBA) is a central procedure in the management of faciocraniosynostoses. In techniques with internal distraction, two sets of devices are generally positioned: bilateral fronto-orbital and temporo-zygomatic distractors, using a temporal tongue and groove osteotomy design. It is believed that distractors must be positioned as parallel as possible in the horizontal and sagittal planes to avoid mechanical conflicts between the sliding bone fragments of the tongue and groove during distraction, and thus optimize the advancement amplitude. Several approaches involving surgical planification and guides for distractor positioning have thus been proposed to monitor distractor placement.To explore the need for surgical planification in distractor placement, the parallelism of the position of the 4 distractors was assessed in 19 FFMBA procedures and we correlated a set of 10 distractor angles with the degree of advancement.We report that the horizontal cut of the tongue and groove can be used as a landmark for the positioning of the lower, temporo-zygomatic, distractor in fronto-facial monobloc advancement. Other parameters (relative position of the two homolateral and the two contralateral distractors and the orientations of the vertical and horizontal cuts of the tongue and groove) do not interfere with distraction, other things being equal.Our results indicate that distractor orientation is not a critical issue in fronto-facial monobloc advancement when devices are positioned as parallel as possible based on visual monitoring.

Stable fixation using absorbable sutures in craniofacial surgery in patients over 24 months of age—a retrospective study

PurposeIn craniofacial surgery, the stable fixation of transposed bone segments is crucial in order to ensure good long-term results. The use of absorbable material in fixation avoids the need for a second surgery, which would otherwise be required to remove osteosynthesis material. The authors of the present manuscript have already demonstrated that absorbable sutures ensure the stable fixation of bone segments in patients up to 24 months of age. However, it has thus far remained unclear whether stable fixation is possible in older patients by using only absorbable sutures due to the slower bone remodelling and prolonged healing time in this cohort.MethodFor the present study, osteosynthesis was performed in 50 patients ranging from 25.7 to 192.1 months of age (mean, 61.4 ± 21.7 months) using solely absorbable sutures (PDS II®, Ethicon, Germany). Post-operative stability and possible restrictions—such as foreign body reactions—were evaluated within clinical and radiological routine follow-ups.ResultsAll children demonstrated clinically and radiologically stable osteosynthesis both directly post-operatively and in follow-ups. No significant foreign body reaction could be seen.ConclusionThe present study demonstrates—for the first time—that absorbable sutures with a longer absorption period are also very well suited for the fixation of bone segments in patients over 24 months of age. The sole use of absorbable sutures in children over 24 months of age is a safe procedure with nearly no foreign body reactions. The procedure enables stable and highly cost-effective osteosynthesis without altering the osteotomy design.

Biomechanical Effect of Distal Tibial Oblique Osteotomy: A Preliminary Finite-Element Analysis.

The biomechanical effect of distal tibial oblique osteotomy (DTOO) on osteoarthritic ankles has not been investigated. Using finite element (FE) models, we aimed to elucidate the effect of DTOO on the ankle contact pressure (CP) distribution. This study included two patients with ankle osteoarthritis who underwent DTOO and one asymptomatic control. Patient-specific FE models were reconstructed by matching standing radiographs with supine computed tomography scans. The joint contact area (CA) and maximumCPon the articular surface of the talus were calculated before and after DTOO and compared with those of the control. In the control, the CA was 584 mm2 and the maximum CP was 2.6 MPa. In case 1, the CA increased by 125% from 166 mm2 preoperatively to 375 mm2 postoperatively, accompanied by a 36% decrease in the maximum CP from 9.8 MPa to 6.3 MPa. Similarly, in case 2, the CA increased by 46% from 301 mm2 to 439 mm2, accompanied by a 27% decrease in the maximum CP from 6.7 MPa to 4.9 MPa. This study suggests DTOO improves the biomechanics of the ankle, but not sufficiently compared to the control. This analytical approach may enhance understanding of ankle pathophysiology and assist in the design of the ideal corrective osteotomy.

A neck-sparing short stem shows significantly lower blood loss in total hip arthroplasty compared to a neck-resecting short stem

Short stems are associated with a significantly lower blood loss (BL) compared to straight stems in total hip arthroplasty (THA). Different types of stems differ in design, fixation and level of femoral neck osteotomy. Therefore, we sought to evaluate the difference regarding the perioperative BL between two short stems with different designs in direct anterior approach (DAA). A total of 187 THA performed by a single surgeon were analysed. 107 patients received a neck-resecting (Group A) and 80 patients a neck-sparing short stem (Group B). Blood counts of the day before surgery and of two days after surgery were evaluated. Total blood volume and BL were calculated. Additionally, duration of surgery was analysed. The perioperative BL was significantly lower in Group B (451.4 ± 188.4 ml) compared to Group A (546.6 ± 232.7 ml; p = 0.002). The postoperative haematocrit (31.6 ± 3.7% vs. 30.4 ± 4.4%; p = 0.049) and haemoglobin-level (11.0 ± 1.3 g/dL vs. 10.4 ± 1.5 g/dL; p = 0.002) were significantly higher in Group B. Duration of surgery was significantly shorter in Group B (62.0 ± 11.4 min vs. 72.6 ± 21.8 min; p < 0.001). The use of a neck-sparing short stem leads to a significantly decreased BL compared to a neck-resecting short stem in DAA THA. A less extensively conducted capsular release necessary for optimal femoral exposition might lead to a lower perioperative BL and shorter durations of surgery.

Aesthetic Enhancement of the Gonial Angle and Inferior Mandibular Border in the Chinese Population.

The current absence of a standardized mandibular body osteotomy design poses challenges in surgical planning. Traditional approaches may not suit patients with wider anterior mandibles, potentially resulting in unsatisfactory outcomes. Addressing this issue requires a rational design that combines mandibular angle and body osteotomies for improved clinical practice. In this retrospective cohort study we aimed to analyze mandibular computed tomography (CT) data with digital methods. The goal was to establish an integrated osteotomy design for both mandibular angle and body procedures and classify prevalent mandibular types in the Chinese Han population for surgical guidance. Included were 89 patients who underwent mandibular angle osteotomy without genioplasty between 2016 and 2022 at Peking University Third Hospital. Mimics 21.0 software facilitated CT data reconstruction and osteotomy planning. Postoperative effects were assessed through imaging, complications, and surveys, leading to mandibular type classification. Mandibular angles were categorized by 3 types, based on osteotomy range. Type I involved mandibular body osteotomy only, type II mandibular angle osteotomy only, and type III both mandibular angle and body osteotomies. Distribution within the cohort was 2.25%, 8.99%, and 88.76% for types I, II, and III respectively. Patient satisfaction was high, with minor and major complications at 47.19% and 1.12% by Clavien-Dindo classification. Utilizing Mimics software, we established an integrated osteotomy design and categorized mandibular types. Findings offer valuable guidance for mandibular angle surgery and contribute to understanding of Asian mandibular morphology.

PACS and Photoshop assisted isosceles triangle osteotomy and Kirschner wire tension buckle fixation in the treatment of cubitus varus in children

To investigate the clinical efficacy of picture archiving and communication system (PACS) and Photoshop assisted isosceles triangle osteotomy and Kirschner wire fixation with tension band in the treatment of cubitus varus in children. The clinic data of 20 children with cubitus varus treated with isosceles triangle osteotomy of distal humerus and Kirschner wire fixation with tension band from October 2014 to October 2019, were retrospectively analyzed. There were 13 males and 7 females, aged from 3.2 to 13.5 years old, the median age was 6.65 years old. PACS system was applied for the osteotomy design preoperatively, simulating and measuring the side length of isosceles triangle osteotomy. Then, Photoshop system was used to simulate the preoperative and postoperative osteotomy graphics, which could guide precise osteotomy during operation. All the 20 patients were followed up for 20 to 24 months, with a median of 22.5 months. At the last follow-up, the carrying angle of the affected limb was 5 ° to 13 °, with a median of 8.3 °. The clinical efficacy was evaluated according to the Flynn elbow function score:excellent in 16 cases, good in 2 cases, and fair in 2 cases. The treatment of cubitus varus in children by isosceles triangle osteotomy and Kirschner wire fixation with tension band assisted by PACS and Photoshop system has shown good clinical outcome.

Multidirectional Cranial Distraction Osteogenesis for Craniosynostosis

In this article we explain in detail the Multidirectional Cranial Distraction Osteogenesis(MCDO)procedure for treating craniosynostosis, in which the multiple cranial bone flaps are pulled up in different directions by the external distractor with the helmet-type frame. MCDO has several advantages over conventional procedures such as unilateral cranial distraction osteogenesis(UCDO). First, the design of the osteotomy in MCDO is flexible depending on the deformities. Each bone flap can be moved to the desired direction in MCDO, while being moved only in one direction along the axis of the distractor in UCDO. This enables remodeling of the deformed cranium to the desired shape. Second, compared with UCDO, the distance between each bone flap after distraction is narrower in MCDO, allowing earlier bone formation and fusion, and thus a shorter consolidation period. Third, the expansion efficacy of MCDO is greater than that of UCDO. The maximum defects of MCDO were the large amount of osteotomy and the resulting heavy bleeding. Therefore, we have recently attempted to improve the design and procedure of osteotomy. The MCDO method allows all phenotypes of skull deformity to be reshaped by distraction osteogenesis.

Computer-aided Design of Distal Femoral Osteotomy for the Valgus Knee and Effect of Correction Angle on Joint Loading by Finite Element Analysis.

Lateral open-wedge distal femoral osteotomy (DFO) has been used to treat valgus deformity of the knee, with good clinical outcomes. However, there is a lack of biomechanical studies regarding the angle of correction. The objective of this study was to apply computer-aided design (CAD) for osteotomy planning in a three-dimensional (3D) anatomical model and to assess the biomechanical differences among the varying correction angles on joint loading by finite element analysis (FEA). To model different angles of lateral open-wedge DFO correction, the CAD software package Mimics 21.0 was used to accurately simulate the operated knee. The femur was cut to 0°, 2°, 4°, 6°, 8°, and 10° of varus (equivalent to hip-knee-ankle angles of 180°, 178°, 176°, 174°, 172°, and 170°, respectively). The original knee model and the corrected models were processed by FE software. Then, the FE models were subjected to an axial force to obtain the von Mises stress (VMS) and shear stress distributions within the femoral cartilages and menisci. Under a compressive load of 740 N, the highest VMS in lateral and medial compartments of the intact knee model was 3.418 and 3.303 MPa. The maximum value of both the VMS and the shear stress in the lateral compartment decreased as the varus angle increased, but the corresponding values in the medial compartment increased. When the hip-knee-ankle (HKA) angle was 180°, the VMS in the lateral and medial compartments was balanced (3.418 and 3.303MPa, respectively). Meanwhile, when the HKA angle was 178° (3.488 and 3.625MPa, respectively), the shear stress in the lateral and medial compartments was balanced. In addition, the magnitude of change in the stress was significantly higher in the medial compartment (90.9%) than in the lateral compartment (19.3%). The optimal correction angle of the valgus knee is close to neutral alignment or slightly varus (0° - 2°). Overcorrection is not recommended, as it can result in a steep increase of the stress within the medial compartment and may accelerate the process of medial compartment OA.

The Open Book Genioplatsy Technique: A Modification.

Genioplasty is a versatile procedure in the repertoire of a maxillofacial surgeon since the time it was conceptualized by Trauner and Obwegeser in 1957.1 The chin improves the facial profile and renders a definition to the jaw. An aligned and proportionate chin adds ample aesthetic value and youthfulness to the face. In addition, it influences the apparent length of the face. Genioplasty holds the potential to alter the dynamics of facial harmony with minimal effort.2 Failure to perform a much required genioplasty can jeopardize the outcome of hours of an otherwise successful major orthognathic or cosmetic surgery.3 The slope and nature of rotation of the osteotomized segments dictate the extent of vertical and horizontal changes.4 In this article, we attempt to introduce a modification to the existing plethora of genioplasty techniques, particularly aimed to rectify a short square jaw into a feminine one. This technique comprises two conventional oblique osteotomies that split the chin into two components, superior and inferior. A margin of 5 mm is kept superiorly from the root tip, inferiorly from the lower border of mandible, and laterally from the mental foramen. Additional stripping of muscles along the lower border of the mandible ensures adequate mobility of the osteotomized inferior segment. The osteotomized segment is rotated outward and downward at an angle of about 30 to 40 degrees, wherein the tip of the inferior osseous segment is regarded as the prominence of the newfound mentum and the anterior surface of the chin becomes the lower border of the mandible (Fig. 1). The osseous segments are secured using two four-hole, 2.0-mm titanium plates (Fig. 2). Bony margins are smoothed. Hemostasis is achieved. Closure is performed done using 4-0 Vicryl sutures. A 1-year pictorial and radiographic follow-up is charted. The same substantiates the successful outcome of the procedure in terms of desired vertical increment, horizontal augmentation, a feminine round chin with a pointy upheal, and desired labiomental fold.Fig. 1.: Schematic representation of the open book genioplasty technique, in which point A becomes the newfound chin prominence, B becomes the lower border of the mandible, and C is the thickness of the mandible seen upon rotation.Fig. 2.: Osseous segment secured using titanium plates and screws depicting an open book fixation.The design of this open book osteotomy can be deemed ideal for a patient with an existing broad chin who desires a sharper, more feminine one. We have so far performed this procedure on female patients, who require a horizontal advancement of about 10 to 13 mm. The greatest advantage lies in negating a step formation along the lower border of the mandible, contributing to a smooth jawline. The downward rotation of the inferior segment helps acquire additional length, thus leading to a vertical increment in the lower half of the face. The possibility of a dual-plane augmentation makes this technique a versatile one. The thickness of the mentum is a vital consideration, as the osseous volume directly translates to the extent of advancement that can be achieved. In our vast clinical experience, the proposed open book genioplasty technique has had gratifying results with the desired osseous and soft-tissue outcomes in female patients with a short, square chin. ACKNOWLEDGMENT This study conformed to all guidelines of the Declaration of Helsinki. DISCLOSURE The authors have no financial interest to declare in relation to the content of this article. No funding was received for this work.

Computer-aided Planning and Execution in Facial Gender Surgery: Approaches, Concepts, and Implementation.

Summary:Facial gender surgery (FGS) involves major surgical modification of the craniofacial soft tissues and skeleton. Computer-aided surgery (CAS) has improved precision and accuracy of osteotomies and decreased operative time in complex reconstructive craniofacial surgery. FGS is a natural application for CAS because the procedures are not only technically challenging but also demand a high standard of aesthetic results. Planning FGS cases virtually enables better and more reproducible results through simulated surgical planning and precise execution of osteotomies in surgical fields with limited exposure. We describe our experience with CAS in FGS for each of the facial thirds to introduce new concepts for conceptual planning of osteotomy design and patient-specific implants.

Assessment of an Artificial Intelligence Mandibular Osteotomy Design System: A Retrospective Study.

In this study, an AI osteotomy software was developed to design the presurgical plan of mandibular angle osteotomy, which is followed by the comparison between the software-designed presurgical plan and the traditional manual presurgical plan, thus assessing the practicability of applying the AI osteotomy software in clinical practices. (1) Develop an AI osteotomy software: design an algorithm based on convolutional neural networks capable of learning feature point and processing clustering segmentation; then, select 2296 cases of successful 3D mandibular angle osteotomy presurgical plans, followed by using those 2296 cases to train the deep learning algorithm; (2) compare the osteotomy presurgical plan of AI osteotomy software and that of manual: first step: randomly selecting 80 cases of typical female head 3D CTs, and designing those 80 cases by means of AI osteotomy software designing (group A) and manually designing (group B), respectively; second step: comparing several indexes of group A and those of group B, including the efficiency index (time from input original CT data to osteotomy presurgical plan output), the safety index (the minimum distance from the osteotomy plane to the mandibular canal), the symmetry indexes (bilateral difference of mandibular angle, mandibular ramus height and mandibular valgus angle) and aesthetic indexes (width ratio between middle and lower faces (M/L), mandibular angle and mandibular valgus angle). The efficiency index: the design time of group A is 1.768±0.768 min and that of group B is 26.108±1.137 min, with P=0.000; the safety index: The minimum distances from the osteotomy plane to the mandibular canal are 3.908±0.361mm and 3.651±0.437mm, p=0.117 in groups A and B, respectively; The symmetry indexes: Bilateral differences of mandibular angle are 1.824±1.834° and 1.567±1.059° in groups A and B, respectively, with P=0.278; bilateral differences of mandibular ramus height are 2.083±1.263 and 2.965±1.433, respectively, with P=0.119 in groups A and B; Aesthetic indexes: M/L in groups A and B is 1.364±0.074 and 1.371±0.067, respectively, with P=0.793; mandibular angles in groups A and B are 127.724±5.800° and 127.242±5.545°, respectively, with P=0.681; Valgus angles in groups A and B are 11.474±5.380 and 9.743±4.620, respectively, with P=0.273. With high efficiency, as well as safety, symmetry and aesthetics equivalent to those of a manual design, the AI osteotomy software designing can be used as an alternative method for manual osteotomy designing. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Immediate precision of the digital osteotomy template in the digital stackable template: a clinical study.

This study aimed to evaluate the immediate accuracy of the digital osteotomy template in the digital stackable template. From November 2018 to January 2020, 4 patients with dentition loss were selected from the Prosthodontics Department, West China Stomatological Hospital. All patients met the conditions for immediate planting and immediate restoration. Owing to the lack of vertical target-restoration space, the implantation plan included intraoperative osteotomy. According to the preoperative cone beam CT (CBCT) data, combined with aesthetic digital smile design (DSD) analysis, virtual wax design, and so on, the ideal bone plane design was performed. According to the virtual osteotomy plane, the virtual implantation plan was designed, and then the digital stackable template assuming osteotomy template, implantation guide, and temporary restoration were made and 3D printed. Osteotomy was performed under the guidance of digital osteotomy template during the operation. The preoperative CBCT and postoperative CBCT of all patients overlapped, the deviation between the actual osteotomy and the ideal osteotomy was calculated, and the angle deviation between the postoperative bone plane and the ideal bone plane was measured. The ave-rage volume deviation between the postoperative design and the ideal one was 492.94 mm³, accounting for 21.21% of the preset osteotomy volume. The average deviation between the postoperative osteotomy and the ideal osteotomy in four patients was 0.024 8 mm. The average angle between the postoperative bone plane and the ideal bone plane was 6.03°. The displacement deviation of virtual osteotomy design and the actual osteotomy one under the guidance of digital osteotomy template in the digital stackable template are highly consistent with the original design. Thus, this clinical technique is worth popularizing, accurate, and quantifiable.

Parametrizing the genioplasty: a biomechanical virtual study on soft tissue behavior

PurposeSliding genioplasty is used to surgically correct a retruded or misaligned chin: in this procedure, an osteotomy is performed and the bony segment is repositioned. In this study we investigate the effect of surgical parameters (bony segment movement, osteotomy design) on postop soft tissue changes in a patient cohort.MethodsSeven patients were retrospectively recruited. Cone beam computed tomography data were obtained and soft tissue and bone shape reconstructions were performed. 3D models were created and surgical cuts were replicated according to postop scans. Each model was imported in ANSYS 2019R1 (Ansys Inc, USA) for simulation: the effect of variation in osteotomy plane as well as extent of bony segment movement were assessed by means of design of experiment: surgical parameters were varied in a surgically acceptable range and the soft tissue predictions were evaluated as displacement output of five craniometric landmarks.ResultsSimulation results show the overall changes of the lower third of the face are sensitive to changes in horizontal and vertical displacement of the bony segment as well as segment rotation. No significant changes in the soft tissue response were to attribute to the osteotomy design.ConclusionsOur results are consistent with experimental findings reported in the literature: when planning genioplasty in orthognathic surgery, particular focus on the segment movement (horizontal translation, vertical translation and rotation), rather than on the design of the osteotomy itself, should be considered.

Influence of implant geometry and osteotomy design on early bone healing: A pre‐clinical in vivo study

To analyze the early stages of osseointegration around implants with different geometry following installation in sites using different osteotomy protocols. Two types of implants were installed using regular or modified (reduced diameter) osteotomy protocols in mandibular premolar/molar regions following tooth extraction in six dogs. Three implant site categories were created: Reference (A implant and regular osteotomy), Test-1 (B implant and regular osteotomy), and Test-2 (B implant and modified osteotomy). Implant installation procedures were repeated after 4 and 6weeks. The insertion torque (ITQ) was measured during implant installation and resonance frequency analysis providing implant stability quotient (ISQ) values was performed following implant installation and once every week during the course of the study. Biopsies were obtained immediately after the 3rd installation procedure and prepared for histological analysis. The modified osteotomy protocol created a higher insertion torque (ITQ). The analysis also revealed a correlation between insertion torque at implant installation and radiographic bone loss after 6weeks of healing. The decline in ISQ values during healing was more pronounced at Test-2 than other sites. While the degree of bone-to-implant contact (BIC%) in the marginal area was similar in test and reference sites at 6weeks of healing, Test-2 implants presented with a significantly higher BIC% in the mid and apical areas than Test-1 implants. It is suggested that placement of implants in undersized osteotomy sites will result in an increased remodeling of the cortical bone during the early healing process.

Risk Factors for Occipital Step-Off Deformities in Posterior Vault Distraction Osteogenesis.

The goal of this study was to investigate patient specific factors and surgical techniques that affect occipital step-off deformity in children undergoing posterior vault distraction osteogenesis (PVDO). Patients who underwent PVDO were retrospectively reviewed and included if a high resolution three-dimensional computed tomography scan was available 1-year post-distractor removal. Two craniofacial surgeons were blinded to individual subjects and presented with 3 still images of three-dimensional bone reconstructions and asked to rate the degree of step off: none, mild, moderate, or severe. The data were analyzed with multinomial logistic regressions and other appropriate statistics. Forty-one patients met inclusion criteria. All patients had multisuture or bicoronal craniosynostosis. Multinomial logistic regression identified age at PVDO (Cox and Snell = 0.487, P < 0.001) as a predisposing factor and one potentially protective factor, height of osteotomy (Cox and Snell = 0.394, P = 0.004) in univariate models. Post-hoc pairwise Mann-Whitney U test revealed there was decreased step-off rating when comparing osteotomy below torcula (median 0, [IQR 0, 3]) and above torcula (median 3 [IQR 1, 4]; P = 0.036) as well as a decreased step-off when below inion (median 0 [IQR 0, 1]; P = 0.001) was compared to above the torcula. Older age at PVDO predict increased risk of developing an occipital step-off deformity after PVDO, while design of the occipital osteotomy below the inion is protective. Barrel staves with greenstick outfracture did not lower the risk of occipital step-off in this sample, the reasons for which are unclear.

Application of picture archiving and communication systems in lateral wedge osteotomy for cubitus varus deformity in teenagers

To investigate effectiveness of picture archiving and communication systems (PACS) in lateral wedge osteotomy for cubitus varus deformity in teenagers. A clinical data of 16 teenagers with cubitus varus deformity between July 2014 and July 2016 was retrospectively analyzed. All patients were treated with lateral wedge osteotomy and fixed with plate. Before operation, the osteotomy design (the osteotomy angle and length) was done in the PACS, including the carrying angle of healthy limb and the varus angle of affected side. There were 10 males and 6 females, with an average age of 11.4 years (range, 10-17 years). The disease duration ranged from 2 to 10 years (mean, 5.6 years). The preoperative X-ray film showed that the supracondylar fractures of the humerus had all healed, and 9 cases had internal rotation deformity; the varus angle of the affected side was 19.5°-33.5°. After operation, the fracture healing and cubitus varus deformity correction were observed by X-ray films, the elbow function was evaluated by Mayo scoring, and the elbow range of motion was detected. There was no significant difference between the actual intraoperative osteotomy angle and length and the preoperative design ( P>0.05). The hospital stay was 2-8 days, with an average of 4.5 days. No complication such as incision infection or ulnar nerve injury occurred. All 16 cases were followed up 12-18 months, with an average of 14 months. X-ray films showed that the osteotomy healed at 2-7 months after operation, with an average of 2.5 months. The internal fixators were removed within 8-14 months after operation (mean, 12.0 months). X-ray films measurement showed that the carrying angle of the affected side recovered to (10.3±2.0)° at 1 day after operation, which was not significantly different from that of the healthy side [(10.6±1.5)°] before operation ( t=0.480, P=0.637). The carrying angle of the affected side was (9.8±2.6)° at 1 year after operation, which was not significantly different from that of the healthy side [(10.4±1.6)°] at the same time point ( t=0.789, P=0.438). At 1 year after operation, the ranges of flexion and extension of affected side were (131.6±8.4)° and (6.4±2.6)°, respectively; and the ranges of flexion and extension of healthy side were (134.2±6.3)° and (5.9±2.2)°, respectively. There was no significant difference between the healthy and affected sides ( t=1.143, P=0.262; t=0.587, P=0.561). The elbow joint function at 1 year after operation evaluated by Mayo scoring standard rated as excellent in 9 cases, good in 6 cases, and fair in 1 case, and the excellent and good rate was 93.7%. Before lateral wedge osteotomy, the PACS is used to design the osteotomy angle and length, which can guide the operation and make the osteotomy more accurate and simple.

The UnderSpinal Osteotomy: A modified low Lefort I osteotomy to correct maxillary dentoalveolar protrusion

Maxillary dentoalveolar protrusion is a common dentofacial deformity in some communities. The gold standard movement to treat this deformity is maxillary setback although it is normally not the first choice due to surgical difficulty. The aim of this study was to present The UnderSpinal Osteotomy a Low Lefort I Osteotomy modified for maxillary setback for correcting dentoalveolar protrusion. This osteotomy design prevents the loss of nasal bone support and preserves the nasal chamber volume in cases of maxillary protusion.

A Novel Trapezoid Concept of Fibula Cutting Guide for Mandible Angle Reconstruction.

Virtual surgical planning (VSP) has revolutionized the planning process in the reconstruction of the mandible with a free fibula flap. The traditional planning and design use a triangular osteotomy guide with a closing wedge movement at the angle. With virtual surgical planning, the authors found an additional lateral mandibular tilt angle and tried to incorporate it in our design of osteotomy guide. The authors have proposed a novel design in a trapezoid shape to accommodate the lateral tilt angle in our osteotomy design. Incorporating the two angles in one angle design improves the aesthesis of the reconstructive procedure and saves operative time.