The impact of surgery resident training on the duration of tibial plateau leveling osteotomy surgery.

OBJECTIVE: To investigate the impact of surgery resident training on surgery duration in tibial plateau leveling osteotomy (TPLO) and evaluate whether surgery duration differs with each year of residency training. STUDY DESIGN: Retrospective medical record review. ANIMALS: A total of 256 client-owned dogs underwent TPLO. METHODS: Records of dogs that underwent TPLO between August 2019 and August 2022 were reviewed. The effects of the surgeon (faculty/resident) and the procedure (arthrotomy/arthroscopy) on TPLO surgery duration were examined with an analysis of variance, and geometric least squares means (GLSM) were compared. A linear mixed effects model (LMM) was fitted to quantify fixed and random effects. RESULTS: Four faculty surgeons performed 74 (29%) TPLOs, while 10 residents performed 182 (71%) TPLOs under the direct supervision of a faculty surgeon. All TPLOs were conducted with arthrotomy (109; 43%) or arthroscopy (147; 57%). Overall, residents (GLSM, 153 min) required 54% more surgery duration than faculty surgeons (GLSM, 99 min). Surgery duration among first-year residents (GLSM, 170 min) was 15% longer than second- (GLSM, 148 min) and third-year (GLSM, 147 min) residents, whereas the duration did not differ statistically between second- and third-year residents. Arthroscopy, meniscal tear treatment, surgery on the right stifle, and increasing patient weight were also associated with longer surgery duration. CONCLUSION: The duration of TPLO surgery significantly decreased after the first year of residency, but did not decrease afterward. CLINICAL SIGNIFICANCE: The results will aid with resource allocation, curricula planning, and cost management associated with resident training.

Learning Curve for Minimally Invasive Surgery and How to Minimize It.

In this article the authors discuss their experience of performing minimally invasive surgery, with emphasis on technique and how to avoid pitfalls. They also discuss the educational literature for learning new techniques and how to shorten the "learning curve."

Lapidus, a Percutaneous Approach.

Described in the early 1900s by Albrecht and Lapidus, the Lapidus procedure became an important tool in the armamentarium. With the increase of percutaneous techniques, the development of a percutaneous Lapidus seemed obvious.

Evolution of Minimally Invasive Surgery in Hallux Valgus.

Minimally invasive (MIS) or percutaneous surgery has evolved rapidly through the development of novel techniques with precise description, correct indications, and the incorporation of modifications of safe and effective techniques described in open surgery. The correct term to describe these procedures should be percutaneous and MIS should be reserved for procedures between percutaneous and open surgery (eg, osteosynthesis). According to results, third-generation techniques are useful, effective, and easier than open procedures. It seems that MIS surgery has an extensive learning curve, and therefore it may be difficult to duplicate the results shown on already-published data.

The learning curve for performing three-column osteotomies in adult spinal deformity patients: one surgeon's experience with 197 cases.

BACKGROUND CONTEXT: Three-column osteotomy (3CO) is used to correct rigid adult spinal deformity. It presents risk of complications because it involves extensive osseous resection and spinal destabilization. PURPOSE: Our purpose was to characterize the learning curve for performing 3CO in adult spinal deformity patients. DESIGN: Retrospective review. PATIENT SAMPLE: A surgical registry at a tertiary care center was used to identify 238 cases of 3CO for correction of adult spinal deformity by 1 surgeon between 2005 and 2014. Patients with at least 1 year of clinical and radiographic follow-up were included (n=197; mean duration of follow-up, 43 months; range, 12-121). OUTCOME MEASURES: We quantified associations between surgeon experience and (1) estimated blood loss per vertebral level fused (EBL/VLF), (2) incidence of new neurologic deficits, (3) incidence of reoperation for instrumentation failure, (4) operative time in minutes, and (5) magnitude of correction at the level of the osteotomy. METHODS: The learning curve for binary outcomes was demonstrated using a LOWESS smoother plot of the probability of occurrence. Change in risk was calculated using a generalized linear model with link identity and binomial family. The learning curve for continuous variables was demonstrated using a scatter plot and a line of best fit based on linear regression analysis. Alpha=0.05. RESULTS: EBL/VLF decreased by a mean of 19.7 mL (95% confidence interval [CI]: 11.3-28.1) with each 10 cases (decrease of 388 mL/level fused by the end of the study period). The risk of a neurologic deficit declined by 7.98% (95% CI: 7.98%, 7.99%) with every 100 cases. The risk of reoperation declined by 1.99% (95% CI: 0.83%, 3.17%) with every 10 cases until the 100th case. After that point, there was no significant change in the probability of reoperation (p>.05). The magnitude of correction and operative time did not change with increasing surgeon experience (p>.05). CONCLUSION: Incidence of reoperation for instrumentation failure, incidence of new neurologic deficits, and estimated blood loss improved with increasing surgeon experience at performing 3CO. Most outcomes, except the risk of reoperation, improved through the last case.

Structured-mentorship Program for Periacetabular Osteotomy Resulted in Few Complications for a Low-volume Pelvic Surgeon.

BACKGROUND: The Bernese periacetabular osteotomy (PAO) is a complex surgical procedure with a substantial learning curve. Although larger hospital and surgeon procedure volumes have recently been associated with a lower risk of complications, in geographically isolated regions, some complex operations such as PAO will inevitably be performed in low volume. A continuous structured program of distant mentoring may offer benefits when low numbers of PAOs are undertaken, but this has not been tested. We sought to examine a structured, distant-mentorship program of a low-volume surgeon in a geographically remote setting. QUESTIONS/PURPOSES: The purposes of this study were (1) to identify the clinical results of PAO performed in a remote-mentorship program, as determined by patient-reported outcome measures and complications of the surgery; (2) to determine radiographic results, specifically postoperative angular corrections, hip congruity, and progression of osteoarthritis; and (3) to determine worst-case analysis of PAO survivorship, defined as nonconversion to THA, in a regionally isolated cohort of patients with a high rate of followup. METHODS: Between August 1992 and August 2016, 85 PAOs were undertaken in 72 patients under a structured, distant-mentorship program. The patients were followed for a median of 5 years (range, 2-25 years). There were 18 males (21 hips) and 54 females (64 hips). The median age of the patients at the time of surgery was 26 years (range, 14-45 years). One patient was lost to followup (two PAOs) and one patient died as a result of an unrelated event. Patient-reported outcome measures and complications were collected through completion of patient and doctor questionnaires and clinical examination. Radiographic assessment of angular correction, joint congruity, and osteoarthritis was undertaken using standard radiology software. PAO survivorship was defined as nonconversion to THA and is presented using worst-case analysis. The loss-to-followup quotient-number of patients lost to followup divided by the number of a patients converted to THA-was calculated to determine quality of followup and reliability of survivorship data. RESULTS: The median preoperative Harris hip scores of 58 (range, 20-96) improved postoperatively to 78 (range, 33-100), 86 (range, 44-100), 87 (range, 55-97), and 80 (range, 41-97) at 1, 5, 10, and 14 years, respectively. Sink Grade III complications at 12 months included four relating to the PAO and one relating to the concomitant femoral procedure. The median lateral center-edge angle correction achieved was 22° (range, 3°-50°) and the median correction of acetabular index was 19° (range, 3°-37°). Osteoarthritis progressed from a preoperative mean Tönnis grade of 0.6 (median, 1; range, 0-2) to a postoperative mean of 0.9 (median, 1; range, 0-3). Six hips underwent conversion to THA: five for progression of osteoarthritis and one for impingement. At 12-year followup, survivorship of PAO was 94% (95% confidence interval [CI], 85%-98%) and survivorship with worst-case analysis was 90% (95% CI, 79%-96%). The loss-to-followup quotient for this study was low, calculated to be 0.3. CONCLUSIONS: When PAO is performed using a structured process of mentoring under the guidance of an expert, one low-volume surgeon in a geographically isolated region achieved good patient-reported outcomes, a low incidence of complications at 12 months, satisfactory radiographic outcomes, and high survivorship. A structured distant-mentorship program may be a suitable method for initially learning and continuing to perform low-volume complex surgery in a geographically isolated region. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Teaching of distal radius shortening osteotomy: three-dimensional procedural simulator versus bone procedural simulator.

In order to facilitate the learning of distal radius shortening osteotomy by junior surgeons, the main assumption was that using a three-dimensional procedural simulator was better than a bone procedural simulator. After viewing a video, ten junior surgeons performed a distal radius shortening osteotomy: five with a bone procedural simulator (Group 1) and five with a three-dimensional procedural simulator (Group 2). All subsequently performed the same surgery on fresh cadaveric bones. The duration of the procedure, shortening of the radius, and the level of osteotomy were significantly better in Group 2. The three-dimensional procedural simulator seems to teach distal radius osteotomy better than a bone model and could be useful in teaching and learning bone surgery of the wrist.

102 lumbar pedicle subtraction osteotomies: one surgeon's learning curve.

PURPOSE: Pedicle Subtraction Osteotomy (PSO) is an effective surgical technique for the correction of fixed sagittal malalignment of the spine. It is a demanding technique that requires a long learning curve. The aim of this study is to analyze a surgeon's learning curve for lumbar PSO in relation to the preoperative, perioperative, and postoperative management, with assessment of the global outcome. MATERIALS AND METHODS: 102 patients operated over an 8-year period were included, distributed in 3 groups over the time, and retrospectively analyzed. The following data were collected: demographic characteristics, preoperative and postoperative radiological parameters, operative technical details, and complications. Multiple regression analysis was performed, and while the number of cases was the predictor, other variables such as demographic, radiographical, and surgical variables were considered as a covariate in the final model. RESULTS: When comparing the first group and the last group of patients, the mean surgical time had decreased by 50 min, the estimated blood loss was decreased by 655 ml, and a significant decrease in dural tear occurrence was noticed. In addition, we found a significant decrease in the hospital stay length. Multivariate linear regression analysis showed that when the surgeon's experience doubles, the operative time decreases by 29 min, the blood loss by 281 ml, and the odds of hospital stay ≥ 21 days decrease by 0.66 times. CONCLUSION: PSO technique has a relatively long learning curve. This study showed that accumulating the experience over the years, while performing cases on a regular basis, is definitely the key in mastering this complex and risky technique, with significant improvements in the perioperative parameters that directly impact the recovery and global outcome. These slides can be retrieved under Electronic Supplementary Material.

Distracción maxilar con dispositivos internos en pacientes fisurados: Planificación virtual y transferencia de datos al campo quirúrgico / Maxillary distraction with internal devices in cleft patients: virtual planing and transference of dates to surgical field

Objetivo. Los dispositivos internos de distracción maxilar han sido poco utilizados debido a la dificultad que supone su colocación precisa. Esto se debe a que pequeñas imprecisiones en su orientación dan lugar a grandes imprecisiones en la posición final del hueso distraído. En este sentido, la cirugía asistida por ordenador es una herramienta de gran ayuda para alcanzar la máxima precisión. El objetivo de este trabajo es presentar nuestro protocolo de planificación de la posición de distractores internos, así como un nuevo objeto CAD/CAM para transferir los datos al campo quirúrgico. Material y método. Se planifica de forma virtual el avance maxilar de 2 pacientes fisurados y los vectores de movimiento virtual. Para la transferencia de datos al campo quirúrgico se utiliza una férula especial con acoples laterales que orientan el vector de distracción. Resultados. Dos pacientes fueron intervenidos con resultados satisfactorios. Conclusión. Tanto el protocolo de planificación virtual del vector de distracción como el objeto CAD/CAM para transferencia de datos al campo quirúrgico presentado son útiles para aumentar la precisión en la posición final del maxilar. De esta forma el uso de distractores internos para avances menores de 12 mm resulta una técnica predecible (AU)

Objetive. Maxillary internal distractors have not been widely used since the accurate positioning is challenging. This is because a small deviation in the positioning results in a great deviation in the final position of the distracted maxilla. Computer assisted surgery is a powerful tool to reach accurate results. The authors report a protocol for internal distractor positioning as well as a new object for transferring dates from virtual planning to surgical field. Material and method. Virtual planning was performed to plan the maxillary advance in 2 cleft patients. A wafer with 2 lateral attachments was used to transfer the vector of distraction from virtual planning to surgical field. Results. Satisfactory result was achieved in both patients. Conclusion. This virtual planning protocol as well as the CAD/CAM objet to transfer dates from computer to surgical field are useful in order to achieve a suitable final position of the maxilla. These tools facilitate the positioning of internal distractors, leaving the use of external distractors for advancement greater than 12 mm (AU)

Teaching and practice patterns of lateral osteotomies for rhinoplasty.

PURPOSE: Lateral osteotomies are important during rhinoplasty and represent a challenging technique that otolaryngology and plastic surgery trainees must learn. The approaches for osteotomies are difficult to teach as they are accomplished through tactile feedback. Trends in teaching and practice patterns of lateral osteotomies are poorly described in the literature, and this study aims to fill this knowledge gap. MATERIALS AND METHODS: Members of the American Academy of Facial Plastic and Reconstructive Surgery were surveyed to characterize surgeon preferences for intranasal versus percutaneous lateral osteotomies and understand how techniques are taught. RESULTS: Among surgeons who completed the survey (n=172), 87% reported that they "always" or "mostly" use intranasal lateral osteotomies whereas only 8% "always" or "mostly" use percutaneous approaches. There is no significant trend towards changing osteotomy techniques when teaching trainees. Only 15% of respondents allow trainees to perform lateral osteotomies in more than half of operations. CONCLUSIONS: Most facial plastic surgeons prefer to use intranasal lateral osteotomies. However, many do not allow trainees to perform this critical step during rhinoplasty. This study has implications for both patient care and surgical education.

Educational Cadaveric Module for Teaching Percutaneous and Intranasal Osteotomies in Rhinoplasty.

Lateral osteotomies are essential to rhinoplasty and are performed through percutaneous or intranasal approaches. Both techniques are difficult to teach as they rely on tactile feedback. Thus, it is critical to understand trainee learning curves to minimize complications. Herein, we aim to (1) demonstrate an educational module for teaching lateral osteotomies and (2) examine potential differences in outcomes between the 2 surgical approaches when performed by trainees. After a hands-on cadaveric laboratory, trainees (n = 24) reported increased confidence in performing both types of osteotomies ( P < .0001). Completion of the bony cut was similar between intranasal and percutaneous osteotomies (96% vs 75%, P = .097), as was correct placement of the osteotomy (75% vs 67%, P = .53). Intranasal osteotomies were more likely to cause periosteal disruption ( P = .02). This pilot study demonstrates that cadaveric laboratories are an effective way to teach lateral osteotomies and that percutaneous osteotomies may be less likely to cause periosteal disruption in trainees' hands.

Importance of Stereoscopy in Haptic Training of Novice Temporal Bone Surgery.

UNLABELLED: We investigate the effects of stereoscopic simulation on novice trainee surgical performance. METHODS: 20 first year medical students were randomized into a stereo or non-stereo group. Each participant viewed a 13 minute instructional video and then performed 3 mastoidectomy procedures with an in-house haptic temporal bone simulation, using a 3D-capable display with either active (stereo) or inactive (non-stero) shutter glasses. Following training, participants performed an actual mastoidectomy on a single 3D-printed bone model. The printed models were evaluated by 3 blinded neurotologic surgeons using a 7 point grading system. RESULTS: Two-tailed t-tests showed no significant difference in overall performance (mean score across test categories over all subjects) between stereo (M=3.8, SD=1.1) and non-stereo (M=4.4, SD=1.5) conditions (p=0.163). No significant differences existed in any of the assessed sub-domains. CONCLUSIONS: The addition of stereo-vision to haptic training may not affect temporal bone surgical skill acquisition in novice users.

Surgical education of eccentric rotational acetabular osteotomy for hip trainees.

BACKGROUND: Periacetabular osteotomy is an excellent intervention for patients at early-stage osteoarthritis, but surgical education for this technique is more difficult than that for total hip arthroplasty. SUBJECTS AND METHODS: 47 joints were included from patients who underwent eccentric rotational acetabular osteotomy (ERAO) performed by 6 trainees under the instructing physician's guidance. We evaluated operative time, blood loss, radiographic parameters, clinical scores, perioperative complications, and 10-year survival rates. We also compared trainees' cases with 47 joints from patients in a sex- and age-matched control group that underwent ERAO performed by the instructing physician. RESULTS: Hip surgery trainees took an average of 152 minutes and the instructor took 103 minutes. Blood loss during surgery by the trainees and the instructor was 382 and 276 g, respectively. Postoperatively, for the trainee and instructor groups, respectively, the Harris Hip Score improved to 88.9 and 93.7 points; the average centre-edge angle improved to 34.0°and 36.1°; and the average acetabular head index was 93.9% and 95.7%. Perioperative and postoperative complications were observed in 14 patients of the trainee group and 3 patients of the instructor group, which were significantly different (p = 0.0061). The 10-year survival rates were 97.8% and 100% for the trainee and instructor groups, respectively. CONCLUSIONS: Postoperative imaging evaluations showed no evident differences in coverage. Postoperative clinical outcomes were also satisfactory. Thus, under proper guidance, education to hip surgery trainees on operative techniques is possible. Instructors need to make more effort to prevent complications by providing good education.

What Is the Early/Mid-term Survivorship and Functional Outcome After Bernese Periacetabular Osteotomy in a Pediatric Surgeon Practice?

BACKGROUND: The Bernese periacetabular osteotomy (PAO) is a recognized joint-preserving procedure. Achieving joint stability without creating impingement is important, but the orientation target that best balances these sometimes competing goals has not yet been clearly defined. Moreover, the learning curve of this challenging procedure has not been described. QUESTIONS/PURPOSES: The purposes of this study were (1) to determine the 10-year survivorship and functional outcome after Bernese PAO in a single-surgeon series; (2) to review which patient, surgical, and radiographic factors might predict outcome after the procedure; and (3) to define the learning curve for target acetabular correction. METHODS: The first 68 PAOs performed for symptomatic hip dysplasia were retrospectively evaluated. None have been lost to followup with followup less than 2 years. Endpoints for the lost to followup (n = 2) are at the time of when last seen. During the study period, the same surgeon performed 562 pelvic osteotomies (including Salter, Pemberton, Dega and Chiari) and 64 shelf acetabuloplasties. Bernese PAO was used only for symptomatic dysplasia (center-edge angle < 25° and nonhorizontal acetabular roof) in developmentally mature hips without evidence of major joint incongruence or subluxation. Most patients were female (n = 49 [60 hips, 88%]); mean age at operation was 25 years (SD 7). Sixteen hips had previous hip procedures. The study's mean followup was 8 years (range, 2-18 years). Patient-reported functional outcome was obtained using the WOMAC score (best-worst: 0-96). Radiographic parameters of dysplasia (acetabular index [AI], center-edge angle [CEA], congruency, Tönnis grade, and joint space) were evaluated from preoperative and postoperative radiographs using computer software. RESULTS: The 10-year survival rate was 93% (95% confidence interval [CI], 82%-100%); four patients underwent further surgery to the hip in the study period. The mean WOMAC was 12 (range, 0-54). Factors that influenced survival included joint congruency (100% versus 78%; 95% CI, 61%-96%; p = 0.03) and acetabular orientation correction achieved (AIpostoperative < 15° [100% versus 65%; 95% CI, 43-88; p < 0.001] and CEApostoperative 20° to 40° [100% versus 71.9%; 52.8-100; p < 0.001]). Better WOMAC scores were seen if postoperative AI < 15° (7 versus 25, p = 0.005) and CEA between 20° and 40° (7 versus 23, p = 0.005) were achieved. The chances of obtaining acetabular correction within this range improved after the 20(th) procedure (30% versus 70%, p = 0.008). CONCLUSIONS: This study reports excellent results after Bernese PAO in the hands of an experienced pediatric hip surgeon. We advocate cautious correction of the acetabular fragment. Future studies should concentrate on how to determine what the optimal target is and how to achieve it intraoperatively, minimizing the learning curve associated with it. LEVEL OF EVIDENCE: Level III, therapeutic study.

Peak and ceiling effects in final-product analysis of mastoidectomy performance.

BACKGROUND: Virtual reality surgical simulation of mastoidectomy is a promising training tool for novices. Final-product analysis for assessing novice mastoidectomy performance could be limited by a peak or ceiling effect. These may be countered by simulator-integrated tutoring. METHODS: Twenty-two participants completed a single session of self-directed practice of the mastoidectomy procedure in a virtual reality simulator. Participants were randomised for additional simulator-integrated tutoring. Performances were assessed at 10-minute intervals using final-product analysis. RESULTS: In all, 45.5 per cent of participants peaked before the 60-minute time limit. None of the participants achieved the maximum score, suggesting a ceiling effect. The tutored group performed better than the non-tutored group but tutoring did not eliminate the peak or ceiling effects. CONCLUSION: Timing and adequate instruction is important when using final-product analysis to assess novice mastoidectomy performance. Improved real-time feedback and tutoring could address the limitations of final product based assessment.

Learning Curves of Virtual Mastoidectomy in Distributed and Massed Practice.

IMPORTANCE: Repeated and deliberate practice is crucial in surgical skills training, and virtual reality (VR) simulation can provide self-directed training of basic surgical skills to meet the individual needs of the trainee. Assessment of the learning curves of surgical procedures is pivotal in understanding skills acquisition and best-practice implementation and organization of training. OBJECTIVE: To explore the learning curves of VR simulation training of mastoidectomy and the effects of different practice sequences with the aim of proposing the optimal organization of training. DESIGN, SETTING, AND PARTICIPANTS: A prospective trial with a 2 × 2 design was conducted at an academic teaching hospital. Participants included 43 novice medical students. Of these, 21 students completed time-distributed practice from October 14 to November 29, 2013, and a separate group of 19 students completed massed practice on May 16, 17, or 18, 2014. Data analysis was performed from June 6, 2014, to March 3, 2015. INTERVENTIONS: Participants performed 12 repeated virtual mastoidectomies using a temporal bone surgical simulator in either a distributed (practice blocks spaced in time) or massed (all practice in 1 day) training program with randomization for simulator-integrated tutoring during the first 5 sessions. MAIN OUTCOMES AND MEASURES: Performance was assessed using a modified Welling Scale for final product analysis by 2 blinded senior otologists. RESULTS: Compared with the 19 students in the massed practice group, the 21 students in the distributed practice group were older (mean age, 25.1 years), more often male (15 [62%]), and had slightly higher mean gaming frequency (2.3 on a 1-5 Likert scale). Learning curves were established and distributed practice was found to be superior to massed practice, reported as mean end score (95% CI) of 15.7 (14.4-17.0) in distributed practice vs. 13.0 (11.9-14.1) with massed practice (P = .002). Simulator-integrated tutoring accelerated the initial performance, with mean score for tutored sessions of 14.6 (13.9-15.2) vs. 13.4 (12.8-14.0) for corresponding nontutored sessions (P < .01) but at the cost of a drop in performance once tutoring ceased. The performance drop was less with distributed practice, suggesting a protective effect when acquired skills were consolidated over time. The mean performance of the nontutored participants in the distributed practice group plateaued on a score of 16.0 (15.3-16.7) at approximately the ninth repetition, but the individual learning curves were highly variable. CONCLUSIONS AND RELEVANCE: Novices can acquire basic mastoidectomy competencies with self-directed VR simulation training. Training should be organized with distributed practice, and simulator-integrated tutoring can be useful to accelerate the initial learning curve. Practice should be deliberate and toward a standard set level of proficiency that remains to be defined rather than toward the mean learning curve plateau.

Plate selection for fixation of extra-articular distal humerus fractures: a biomechanical comparison of three different implants.

Operative fixation of extra-articular distal humerus using a single posterolateral column plate has been described but the biomechanical properties or limits of this technique is undefined. The purpose of this study was to evaluate the mechanical properties of distal humerus fracture fixation using three standard fixation constructs. Two equal groups were created from forty sawbones humeri. Osteotomies were created at 80mm or 50mm from the tip of the trochlea. In the proximal osteotomy group, sawbones were fixed with an 8-hole 3.5mm LCP or with a 6-hole posterolateral plate. In the distal group, sawbones were fixed with 9-hole medial and lateral 3.5mm distal humerus plates and ten sawbones were fixed with a 6-hole posterolateral plate. Biomechanical testing was performed using a servohydraulic testing machine. Testing in extension as well as internal and external rotation was performed. Destructive testing was also performed with failure being defined as hardware pullout, sawbone failure or cortical contact at the osteotomy. In the proximal osteotomy group, the average bending stiffness and torsional stiffness was significantly greater with the posterolateral plate than with the 3.5mm LCP. In the distal osteotomy group, the average bending stiffness and torsional stiffness was significantly greater with the posterolateral plate than the 3.5mm LCP. In extension testing, the yield strength was significantly greater with the posterolateral plate in the proximal osteotomy specimens, and the dual plating construct in the distal osteotomy specimens. The yield strength of specimens in axial torsion was significantly greater with the posterolateral plate in the proximal osteotomy specimens, and the dual plating construct in the distal osteotomy specimens. Limited biomechanical data to support the use of a pre-contoured posterolateral distal humerus LCP for fixation of extra-articular distal humerus exists. We have found that this implant provided significantly greater bending stiffness, torsional stiffness, and yield strength than a single 3.5mm LCP plate for osteotomies created 80mm from the trochlea. At the more distal osteotomy, dual plating was biomechanically superior. Our results suggest that single posterolateral column fixation of extra-articular humerus fractures is appropriate for more proximal fractures but that dual plate fixation is superior for more distal fractures.

Constructive real time feedback for a temporal bone simulator.

As demands on surgical training efficiency increase, there is a stronger need for computer assisted surgical training systems. The ability to provide automated performance feedback and assessment is a critical aspect of such systems. The development of feedback and assessment models will allow the use of surgical simulators as self-guided training systems that act like expert trainers and guide trainees towards improved performance. This paper presents an approach based on Random Forest models to analyse data recorded during surgery using a virtual reality temporal bone simulator and generate meaningful automated real-time performance feedback. The training dataset consisted of 27 temporal bone simulation runs composed of 16 expert runs provided by 7 different experts and 11 trainee runs provided by 6 trainees. We demonstrate how Random Forest models can be used to predict surgical expertise and deliver feedback that improves trainees' surgical technique. We illustrate the potential of the approach through a feasibility study.