Adherence to the Obeid coronal malalignment classification and a residual malalignment below 20 mm can improve surgical outcomes in adult spine deformity surgery.

PURPOSE: Coronal balance is a major factor impacting the surgical outcomes in adult spinal deformity (ASD). The Obeid coronal malalignment (O-CM) classification has been proposed to improve the coronal alignment in ASD surgery. Aim of this study was to investigate whether a postoperative CM < 20 mm and adherence to the O-CM classification could improve surgical outcomes and decrease the rate of mechanical failure in a cohort of ASD patients. METHODS: Multicenter retrospective analysis of prospectively collected data on all ASD patients who underwent surgical management and had a preoperative CM > 20 mm and a 2-year follow-up. Patients were divided in two groups according to whether or not surgery had been performed in adherence to the guidelines of the O-CM classification and according to whether or not the residual CM was < 20 mm. The outcomes of interest were radiographic data, rate of mechanical complications and Patient-Reported Outcome Measures. RESULTS: At 2 years, adherence to the O-CM classification led to a lower rate of mechanical complications (40 vs. 60%). A coronal correction of the CM < 20 mm allowed for a significant improvement in SRS-22 and SF-36 scores and was associated with a 3.5 times greater odd of achieving the minimal clinical important difference for the SRS-22. CONCLUSION: Adherence to the O-CM classification could reduce the risk of mechanic complications 2 years after ASD surgery. Patients with a residual CM < 20 mm showed better functional outcomes and a 3.5 times greater odd of achieving the MCID for the SRS-22 score.

Anatomical Topographical Investigation of the Medial Branch of the Dorsal Thoracic Branch of the Spinal Nerve in the Segments T10-T12.

INTRODUCTION: The zygapophyseal joints represent one possible cause for back pain. Therefore, many interventions are targeting the denervation of the facet joints. The aim of this study is to describe the course of the medial branch of the dorsal branch of the spinal nerve and its articular branches to the zygapophyseal joints in the segments T10-T12. METHODS: The medial branches in the thoracic segments T10-T12 were dissected in 20 Thiel embalmed cadavers. An Eschenbach magnifying glass (4.0× magnification) was used during dissection preserving the articular branches. The topography and the branching pattern of the medial branches was observed. RESULTS: The course of the nerves in the segments T10-T12 differed from each other because of the different osseous anatomy of each segment. The medial branch at the segment T10 crossed the tip of the transverse process in 28 of the 40 hemivertebral specimens. In the remaining cases it passed superior to the transverse process. At T11 the medial branch ran constantly through an osteofibrous canal. At the segment T12 the medial branches showed a similar course to the medial branches in the lumbar region. In many cases two articular branches, which arose from the medial branch were identified. CONCLUSIONS: The results of this study show a considerable anatomic variety at the segment T10. It also demonstrates that the transverse process is an important landmark to encounter the medial branch. Furthermore, the possibility of a double innervation of the facet joints should always be considered.

Is There a Nerve-free Zone in Which a Subscapularis Split Can Safely be Performed? An Anatomical Study Using Embalmed Specimens.

BACKGROUND: The subscapularis muscle, which is part of the rotator cuff, is located anterior to the shoulder. In anterior approaches to the shoulder, its supplying nerves are at risk of iatrogenic injury, which may cause postoperative complications. It is unclear whether there is any nerve-free zone in which a subscapularis split can be performed without risking nerve damage. QUESTIONS/PURPOSES: In an anatomical study, we asked: (1) With the arm abducted 60° and externally rotated, what are the median and shortest distances between the entrance point of the subscapular nerves into subscapularis muscle and the myotendinous junction of this muscle? (2) What are those distances in other positions of the shoulder? (3) Did those measurements differ between specimen sexes or sides? METHODS: In 84 shoulders of 66 embalmed anatomic specimens, the distance from the myotendinous junction of the subscapularis muscle to the entrance points of the subscapular nerves into the subscapularis muscle was measured using an inelastic thread and a millimeter gauge with the arm abducted 60° and rotated externally. In 16 of 84 shoulders, which were selected randomly, after taking the measurements with the arm abducted 60° and rotated externally, arm positions were changed and further measurements were taken with the arm abducted 60° and rotated neutrally, abducted 60° and rotated internally, and abducted 90° and rotated externally. The positions of the entrance points were described with statistical parameters and compared between different sides, sexes, and joint positions. Measurements were verified using eight fresh-frozen shoulders, showing no difference in distances compared with embalmed specimens and confirming reproducibility of measurements. Absolute distances were used to minimize possible distortion when using correlations and for straightforwardness and clinical applicability. RESULTS: The median (range) distance was 43 mm (24 to 64) for the upper subscapular nerve and 38 mm (23 to 59) for the lower subscapular nerve with the arm rotated externally and abducted 60°. In the 16 subsamples, internal rotation decreased the distance to 34 mm (24 to 49) and 31 mm (15 to 43), respectively, and maximal external rotation and 90° of abduction increased it up to 49 mm (30 to 64) and 41 mm (27 to 56). Comparison of left and right sides yielded no difference. Comparison of sexes showed distances for the lower subscapular nerve of 36 mm (23 to 54) in females versus 39 mm (24 to 60) in males. CONCLUSION: In no specimen did the nerve come closer than 23 mm medial to the myotendinous junction with the arm rotated externally and abducted. Therefore, not exceeding a distance of 20 mm medial to the myotendinous junction with the arm rotated externally seems to provide sufficient protection from nerve injury during surgery. CLINICAL RELEVANCE: Based on the described zone of 20 mm medial to the myotendinous junction, the risk of nerve injury in a subscapularis split approach can be minimized.

Senior Club-Level Rugby Union Player's Positional Movement Performance Using Individualized Velocity Thresholds and Accelerometer-Derived Impacts in Matches.

ABSTRACT: Takamori, S, Hamlin, MJ, Kieser, DC, King, D, Hume, P, Yamazaki, T, Hachiya, M, and Olsen, PD. Senior club-level rugby union player's positional movement performance using individualized velocity thresholds and accelerometer-derived impacts in matches. J Strength Cond Res 36(3): 710-716, 2022-Game demands of professional rugby union players have been well documented; however, there is minimal game demand information using individualized velocity thresholds and collision loads, particularly for amateurs. This study investigated movement patterns of 20 male amateur rugby players during 16 senior premier division one matches using global positioning system (GPS) devices sampling at 10 Hz. Derived GPS variables included distances, velocities, sprinting, and impacts. Data files from 86 player games (≥60 minutes of play per game) were categorized into broad (forwards and backs) and specific (front row, second row, back row, half back, inside back, and outside back) positional groups for analysis. It was most likely that backs covered more distance in the high-speed running (>60% maximal velocity) zone (502 ± 157 m) compared with forwards (238 ± 147 m) (100/0/0%, chances of positive/trivial/negative differences, effect size [ES] = 1.3), performed more striding (backs 1,116 ± 240, forwards 954 ± 240 m, 96/4/0%, ES = 0.5), and sprinting (backs 121 ± 58, forwards 90 ± 65 m, 93/7/0%, ES = 0.5). However, forwards had higher collision loads (35 ± 12 arbitrary units) compared with backs (20 ± 6, 99.9/0.1/0%, ES = 1.3) with back row forwards completing the highest collision load of any playing position (40 ± 13). Our example match movement performance and impact information is valuable to coaches and support staff in preparing player profiles for similar-level rugby players to help manage their workloads.

Ballistic trauma caused by military rifles: experimental study based on synthetic skull proxies.

Rifles are often involved in violent deaths such as homicide and suicide. Consequently, expert knowledge and experimental forensic investigations are important to clarify the nature of ballistic trauma when applied to the human head and neurocranium. This study investigated differences in entrance wound morphology with Synbone® spheres which are described as being comparable to human flat bones. A series of ballistic experiments were conducted using two different rifle calibers (5.56 × 45 mm and 7.62 × 39 mm Full Metal Jacket (FMJ)). Synbone® spheres were used for close-range 0.3 m simulated executions as well as at 25 m and 35 m to simulate urban and military engagements. Results were compared with previously published experimental studies using similar military ammunition. In our study, entry wound morphology closely resembles real forensic cases compared to exit wound and overall shape morphology independently of the distance and the caliber. Circumferential delamination was clearly visible with full metal jacket (FMJ) rounds, yielding similar damage pattern morphology to the human crania. This study documented the presence of hydraulic burst or shock in all ten rounds from all three distances. Krönlein shots were also observed in some cases. Synbone® spheres constitute an acceptable synthetic surrogate for ballistic experiments. The present study offers new initial data on the behavior of Synbone® proxies in ballistic testing of military ammunitions; FMJ gunshot injuries to the human head, for distances that have not previously been published, suggesting that efficient tests can take place under these conditions. Further research on experimental ballistics with a larger number of controlled factors and multiple repetitions is recommended to verify the results of this pilot study before applied in forensic simulations.

Validation of Roebuck 1518 synthetic chamois as a skin simulant when backed by 10% gelatin.

INTRODUCTION: Synthetic skin simulants are used both in wound ballistics and forensic investigations and should display similar mechanical properties to human tissue and therefore need to be validated. It is recognised that skin simulants may have a significantly different performance when different backing combinations are used; therefore, it is essential to specify and control the backing material. Roebuck 1518 synthetic chamois (RBK) backed by 20% ballistic gelatin has been validated as a suitable skin simulant; this study looks at validating the RBK simulant when backed by 10% ballistic gelatin. METHODS: Two layers of RBK synthetic chamois backed by calibrated 10% ballistic gelatin were placed onto the long face of the block and secured. Steel spheres with various sectional densities were fired using a custom-made gas gun to determine the V50 of the simulants and compared with the predicted V50. RESULTS: The results demonstrate that for a sectional density between 2.1 and 6.6 g/cm2, the skin simulants backed by 10% gelatin are within the 35% error bounds predicted by James' patent equation. All samples had a close fit to the regression line (R2 = 0.9738), and a Spearman rho test indicates that there is a "strong" negative correlation between sectional density and the V50 (Rs =- 0.957, p = 0.00). CONCLUSIONS: This validation study confirms that RBK synthetic simulant backed by 10% gelatin is a suitable skin simulant when testing non-deforming projectiles with sectional densities ranging from 2.1 to 6.6 g/cm2. A predictive trend line also indicates that the skin simulant is suitable for non-deforming projectiles with sectional densities ranging from 0.6 to 20 g/cm2 although this needs to be confirmed.

A study into the viability of Synbone® as a proxy for Sus scrofa (domesticus) ribs for use with 5.56-mm open tip match ammunition in ballistic testing.

BACKGROUND: In ballistic testing and forensic reconstruction, there is a need to use repeatable and consistent simulants. While synthetic bone is mechanically similar to human bone, it does not have the same viscoelastic properties. In high-energy impact such as ballistic impacts, bone acts as a stiff, brittle material and fails instantaneously. Therefore, a suitable simulant for use in ballistic testing should have comparable energy deposition to mammalian bones. This preliminary study aims to determine if Synbone® could be a viable proxy for Sus scrofa (domesticus) ribs in ballistic testing. METHODOLOGY: Three thickness of Synbone® were embedded into 10% ballistic gelatin and shot using 5.56-mm ammunition. The models were then analysed to compare the Synbone® to a previous Sus scrofa (domesticus) rib study and focused on the number of fragments within the block, energy deposition, onset of yaw, angle of deviation, the temporary cavity as a percentage of the block and the depth to the temporary cavity centre, depth to maximum gelatin disruption and the permanent wound channel, including shear planes and wound tract diameter. RESULTS: There was no significant difference in the metrics that were compared between Sus scrofa (domesticus) ribs and the three thicknesses of Synbone®, except for a significant difference in the depth to maximum gelatin disruption between the 6 mm (p = 0.009) and 12 mm plate (p = 0.007) and the Sus scrofa (domesticus) ribs. CONCLUSION: This study indicates that the 5-mm Synbone® plate is a suitable proxy for Sus scrofa (domesticus) ribs for use with 5.56-mm OTM ammunition in ballistic testing.

Pseudarthrosis in adult spine deformity surgery: risk factors and treatment options.

PURPOSE: Highlight risk factors for pseudarthrosis in long-segment spinal fusions, collect the approaches carried to address this complication. METHODS: Patients with ASD and fusion of ≥ 4 levels with minimum follow-up (FU) of ≥ 2 years were included. Full-body X-rays were done preoperatively, < 3 months and ≥ 2 years. Oswestry disability index (ODI), Scoliosis Research Society-22 and SF36 assessed pre- and postoperatively. The relationship between demographic, surgical and radiological variables with the development of pseudarthrosis was evaluated. RESULTS: Out of 524 patients included, 65 patients (12.4%) developed pseudarthrosis and 53 underwent revision surgery. Notably, 88% of pseudarthrosis cases are associated with fusion length (OR = 1.17, 95% CI = 1.05-1.292, p = 0.004), osteotomy requirement (OR = 0.28, 95% CI = 0.09-0.85, p = 0.025), pelvic fixation (OR = 0.34, 95% CI = 0.13-0.88, p = 0.026) and combined approaches (OR = 3.29, 95% CI = 1.09-9.91, p = 0.034). Sagittal alignment is not related to the rate of pseudarthrosis. Health related and quality of life scores were comparable at last FU between patients revised for pseudarthrosis and those that didn't require revision surgery (ODI = 28% no revision and 30% revision group). CONCLUSIONS: Pseudarthrosis is not related to malalignment, but with the surgical techniques employed for its treatment. Anterior approaches with anterior support decrease the rate by 30%, while long fusions, osteotomies and pelvic fixation increase its rate.

Benchmarking total hip replacement constructs using noninferiority analysis: the New Zealand joint registry study.

BACKGROUND: The aim of this study was to compare the relative performance of total hip replacement constructs and discern if there is substantial variability in performance in currently commonly used prostheses in the New Zealand Joint Registry (NZJR) using a noninferiority analysis. METHODS: All patients who underwent a primary total hip replacement (THR) registered in the NZJR between 1st January 1999 to June 2020 were identified. Using a noninferiority analysis, the performance of hip prostheses were compared with the best performing contemporary construct. Construct failure was estimated using the 1-Kaplan Meier survival function method to estimate net failure. The difference in failure between the contemporary benchmark and other constructs was examined. RESULTS: In total 135,432 THR were recorded comprising 1035 different THR constructs. Notably 328 constructs were used just once. Forty-eight constructs (62,251 THR) had > 500 procedures at risk at 3 years post-primary of which 28 were inferior by at least 20% relative risk of which, 10 were inferior by at least 100% relative risk. Sixteen constructs were identified with > 500 procedures at risk at 10 years with 9 inferior by at least 20%, of which one was inferior by > 100% relative risk. There were fewer constructs noninferior to the best practice benchmark when we performed analysis by gender. In females at 10 years, from 5 constructs with > 500 constructs at risk, 2 were inferior at the 20% margin. In males at 10 years, there were only 2 eligible constructs of which one was inferior at the 20% margin. CONCLUSIONS: We discerned that there is substantial variability in construct performance and at most time points, just over half of constructs are inferior to the best performing construct by at least 20%. These results can facilitate informed decision-making when considering THR surgery.

Fatal epidural abscess with meningitis: a rare complication of colorectal surgery.

BACKGROUND: Anastomotic leakage following colorectal surgery remains a frequent complication. We report a rare case of a fatal epidural abscess caused by a colo-epidural fistula complicating a laparoscopic proctectomy. CASE PRESENTATION: A 62 year-old-man presented with weight loss, pelvic sepsis and neurological dysfunction four months after closing of the ileostomy following a laparoscopic proctectomy for a rectal adenocarcinoma one year ago. Cross-sectional imaging confirmed an epidural abscess caused by a chronic colorectal anastomotic leak. Systemic antibiotics and laparotomy with defunctioning pelvic loop colostomy were performed. Unfortunately, this management to control the major spinal infection failed. Epidural decompression and debridement was not possible due to his poor condition and the patient subsequently died. CONCLUSION: Colo-epidural fistula can occur as a consequence of colorectal anastomotic leakage. Prior to frank neurology symptoms and sepsis, patients may present with only a low-grade fever. Without prompt and aggressive management of colo-epidural infection, this severe complication can lead to paraplegia and death.

A study into the viability of Synbone® as a proxy for Sus scrofa (domesticus) ribs for use with 7.62 × 51 mm Full Metal Jacket ammunition in ballistic testing.

Forensic reconstructions and ballistic testing requires the use of consistent and repeatable simulants. Synthetic bone has been developed to be mechanically similar to human bone; however, it does not have the same viscoelastic properties. Bone acts as brittle and stiff material and fails instantly under high-energy events such as ballistic impacts. Consequently, bone simulants for use in ballistic testing should show comparable energy deposition to mammalian bones. This study aims to determine if Synbone® flat plates could be a viable proxy for Sus scrofa (domesticus) ribs in ballistic testing with 7.62 × 51 mm Full Metal Jacket ammunition. 5 mm, 6 mm and 12 mm quartered Synbone® plates were embedded into 10% ballistic gelatin and shot using 7.62 mm ammunition. The models were then analysed to compare the Synbone® to a previous Sus Scrofa (domesticus) rib study and focused on energy deposition, the number of fragments within the block, angle of deviation, onset of yaw, the temporary cavity, and the permanent wound channel. No significant difference was seen between the Sus Scrofa (domesticus) and the 5 mm Sybone®. There were significant differences observed between Sus Scrofa (domesticus) ribs and 6 mm Synbone® for the number of fragments, energy deposition and projectile tract diameter, and significant differences seen between Sus scrofa (domesticus) ribs and 12 mm Synbone® for the depth of onset of yaw, energy deposition and projectile tract diameter. This study indicates that the 5 mm Synbone® plate is a suitable proxy for Sus scrofa (domesticus) ribs for use with 7.62 × 51 mm FMJ ammunition in ballistic testing.

A new classification for coronal malalignment in adult spinal deformity: a validation and the role of lateral bending radiographs.

PURPOSE: Coronal malalignment (CM) causes pain, impairment of function and cosmetic problems for adult spinal deformity (ASD) patients in addition to sagittal malalignment. Certain types of CM are at risk of insufficient re-alignment after correction. However, CM has received minimal attention in the literature compared to sagittal malalignment. The purpose was to establish reliability for our recently published classification system of CM in ASD among spine surgeons. METHODS: Fifteen readers were assigned 28 cases for classification, who represented CM with reference to their full-length standing anteroposterior and lateral radiographs. The assignment was repeated 2 weeks later, then a third assignment was done with reference to additional side bending radiographs (SBRs). Intra-, inter-rater reliability and contribution of SBRs were determined. RESULTS: Intra-rater reliability was calculated as 0.95, 0.86 and 0.73 for main curve types, subtypes with first modifier, and subtypes with two modifiers respectively. Inter-rater reliability averaged 0.91, 0.75 and 0.52. No differences in intra-rater reliability were shown between the four expert elaborators of the classification and other readers. SBRs helped to increase the concordance rate of second modifiers or changed to appropriate grading in cases graded type A in first modifier. CONCLUSIONS: Adequate intra- and inter-rater reliability was shown in the Obeid-CM classification with reference to full spine anteroposterior and lateral radiographs. While side bending radiographs did not improve the classification reliability, they contributed to a better understanding in certain cases. Surgeons should consider both the sagittal and coronal planes, and this system may allow better surgical decision making for CM.

Opioids and analgesics use after adult spinal deformity surgery correlates with sagittal alignment and preoperative analgesic pattern.

PURPOSE: To assess pain, health-related quality of life (HRQOL) scores and sagittal parameters of adult spinal deformity (ASD)-operated patients in the context of their analgesic consumption especially opioids (narcotics) over the first year postoperative period. METHODS: In total, 372 patients from a multicenter database were stratified into 3 groups at baseline: 241 patients in the minimal group (no analgesic, or NSAIDs/narcotics weekly or less), 64 in the NSAIDs every day group and 67 in the narcotics every day group. HRQOL and back and leg pain scores were evaluated at 6 months and 1 year postoperatively. Also several sagittal alignment parameters were assessed. RESULTS: Significant improvements in pain and HRQOL scores were observed across all 3 groups by 1 year (P < 0.05) postoperatively. While the minimal group had the best pre- and postoperative HRQOL scores, the NSAID group demonstrated the best improvement in HRQOL. Only the minimal group displayed continued improvement from 6 months to 1 year. 90%, 65% and 40% of minimal, NSAID and narcotic groups of patients, respectively, no longer took any analgesics at 1 year postoperatively. Alternatively, 36% of patients in the narcotics group continued to take narcotics at 1 year. Residual malalignment increased NSAIDs consumption in different groups at 1 year. CONCLUSION: This study evaluated the analgesics use after ASD surgery in relation to the clinical and radiological outcomes. Despite important postoperative opioids consumption in the narcotics group, clinical outcome yet improved. Malalignment parameters demonstrated a predictive value in regard to NSAIDs' usage. These slides can be retrieved under Electronic Supplementary Material.

Are Lipped Polyethylene Liners Associated with Increased Revision Rates in Patients with Uncemented Acetabular Components? An Observational Cohort Study.

BACKGROUND: Recurrent dislocation after THA remains a serious complication that carries with it a high risk of revision surgery. Previous studies have shown reduced dislocation rates with the use of lipped polyethylene (PE) liners in modular uncemented acetabular components, but there may be increased wear because of impingement, which may lead to aseptic loosening in the longer term; whether the aggregate benefit of lipped PE liners outweighs the risks associated with their use remains controversial. QUESTIONS/PURPOSES: We used data from the New Zealand Joint Registry to (1) compare Kaplan-Meier survival rates, (2) rates of revisions for dislocation between neutral and lipped PE liners, and (3) revision rates for aseptic loosening for the four most commonly used modular uncemented cups. METHODS: We used data from the New Zealand Joint Registry (NZJR) to identify 31,247 primary THAs using the four most commonly used uncemented modular acetabular implants from January 1, 1999 to December 31, 2018. The lipped liner group comprised 49% males (9924 of 20,240) compared with 42% (4669 of 11,007) in the neutral group (p < 0.001); 96% (19,382 of 20,240) of patients in the liner group had OA versus 95% (10,450 of 11,007) in the neutral group (p < 0.001). There was no difference in other patient characteristics such as age (mean 66.9 years), BMI (mean 29 ± 6 kg/m) and American Society of Anesthesiologists grade. The mean follow-up was 5.1 years (SD 3.9) and longest follow-up 19.3 years. The NZJR has more than 96% capture rate and data entry is a mandatory requirement of members of the New Zealand Orthopaedic Association. Kaplan-Meier survival rates were compared between 20,240 lipped and 11,007 neutral PE liners. Highly cross-linked polyethylene was used in 99% of lipped liner cups and 85% of neutral liner cups. Associated hazard ratios were calculated using a Cox regression analysis with a Kaplan-Meier revision-free estimates plot. RESULTS: The Kaplan-Meier survival at 10 years for lipped PE liners was 96% (95% confidence interval 95.4 to 96.2) and for neutral liners 95% (95% CI 94.7 to 95.9). After controlling for age, gender approach, femoral head size, and the use of image guidance, the all-cause revision risk was greater for neutral PE liners than that for lipped PE liners (HR 1.17 [95% CI 1.06 to 1.36]; p = 0.032). There was a higher risk of revision for dislocation in those with neutral PE liners than in those with lipped liners (HR 1.84 [95% CI 1.41 to 2.41]; p < 0.001) but no difference in the revision rate for aseptic acetabular component loosening (HR 0.85 [95% CI 0.52 to 1.38]; p = 0.511). CONCLUSIONS: The use of a lipped PE liner is not associated with a higher rate of aseptic loosening in patients who undergo primary THA compared with a neutral PE liner. Lipped PE liners are associated with lower rates of dislocation and lower all-cause revision rates without any increased association with revision rates for wear and aseptic loosening. LEVEL OF EVIDENCE: Level III, therapeutic study.

Infection in neuro-muscular scoliosis deformity correction.

Assess the outcome of a standardised protocol for the treatment of post-operative wound infection in patients undergoing deformity correction for neuro-muscular scoliosis (NMS). Retrospective review of 443 consecutive patients with a minimum 18 months' follow-up, following a primary posterior deformity correction for NMS. In patients who developed a wound complication, the patient demographic and comorbidities, causative pathogen, number of re-operations, length of stay (LOS), rate of cure, and complications were analysed. Forty-four patients (9.9%) developed a wound infection. Marginally more infections were mono-microbial (23) than poly-microbial (21). Coagulase negative staphylococcus and Staphylococcus aureus were the most commonly cultured pathogens. Seventeen patients were treated with antibiotics alone, while 27 patients also required surgical debridement. The average LOS for those treated with antibiotics alone was 12 days (range: 9-15 days), in contrast to those requiring debridement, which was 35 days (range: 35-70 days). All patients were cured from their infection and ultimately achieved fusion. Infection is common in NMS deformity correction. This is marginally more common as a mono-microbial than poly-microbial infection with most pathogens being staphylococcal in origin. Our defined treatment strategy resulted in a cure for all patients and capacity for all patients to achieve fusion.

Variations in Subscapularis Muscle Innervation-A Report on Case Series.

Background and objectives: The subscapularis muscle is typically innervated by two distinct nerve branches, namely the upper and lower subscapular nerve. These usually originate from the posterior cord of the brachial plexus. A large number of variations have been described in previous literature. Materials and Methods: Dissection was carried out in 31 cadaveric specimens. The frequency of accessory subscapular nerves was assessed and the distance from the insertion points of these nerves to the myotendinous junction was measured. Results: Accessory subscapular nerves were found in three cases (9.7%). According to their origin from the posterior cord of the brachial plexus proximal to the thoracodorsal nerve all three nerves were identified as accessory upper subscapular nerves. No accessory lower subscapular nerves were found. Conclusion: Accessory nerves occur rather commonly and need to be considered during surgery, nerve blocks, and imaging procedures.

Cerebral ischaemia following anterior upper thoracic spinal surgery utilizing a partial manubrial resection.

PURPOSE: Firstly, to describe two cases of cerebral ischaemia complicating anterior upper thoracic spinal surgery and define the likely cause of this complication. Secondly, to describe preventative measures and the effect these have had in reducing this complication within our institution. METHODS: Firstly, a review of two cases of cerebral ischaemia complicating anterior upper thoracic spinal surgery utilizing a partial manubrial resection. Secondly, cadaveric dissections of the carotid arteries to determine the effect of neck positioning and aortic arch retraction during a simulated procedure. Thirdly, a retrospective review of 65 consecutive cases undergoing this procedure and assessment of the rate of this complication before and after the adoption of preventative measures. RESULTS: Two cases of carotid artery territory cerebral ischaemia, without radiographic evidence of carotid or cardiac pathology were identified in 50 consecutive cases prior to the implementation of preventative measures. These patients revealed fluctuating hemodynamic instability after placement of the inferior retractor. Cadaveric dissection reveals significant carotid artery traction particularly with neck extension. Since the adoption of preventative measures, no cases of cerebral ischaemia have been encountered. CONCLUSIONS: Cerebral ischaemia is a potential complication of anterior upper thoracic spinal surgery requiring retraction of the aortic arch. This most likely occurs from carotid stenosis due to aortic retraction and therefore, may be reduced by positioning the patient with neck flexion. Continuous non-invasive monitoring of cerebral saturation, as well as actively monitoring for hemodynamic instability and reduced carotid pulsation after retractor placement, allows for early detection of this complication. If detected, perfusion can be easily restored by reducing the retraction of aortic arch.

How to Avoid Posterior Interosseous Nerve Injury During Single-Incision Distal Biceps Repair Drilling.

BACKGROUND: The posterior interosseous nerve (PIN) is occasionally damaged during distal biceps tendon repair. But to our knowledge, no studies have examined the position of the PIN in relation to the bicipital tuberosity in full supination, which is the recommended position during single-incision distal biceps repair or reconstruction QUESTIONS/PURPOSES: (1) What is the anterior safe zone when exposing the anterior tuberosity with the arm in supination? (2) When drilling the radial tuberosity for bicortical button placement in full supination, how should the drill be angled to avoid PIN injury? METHODS: Fifteen adult cadaver elbows had the PIN dissected around the proximal radius. The position of the PIN was measured relative to the most ulnar aspect of the radius at three sites in full supination: at the bicipital tuberosity (bicipital tuberosity-PIN), 10 mm proximal to the bicipital tuberosity (bicipital tuberosity-proximal), and 10 mm distal to the bicipital tuberosity (bicipital tuberosity-distal). We made another measurement by drawing a line from the lateral humeral epicondyle to the radial styloid. The point where the PIN intersects this line, when viewed laterally and measured from the lateral humeral epicondyle, was marked and measured to indicate where it wraps around the radius laterally (PIN-lateral). The last measurement (bicipital tuberosity-lateral) was made where the line from the lateral humeral epicondyle to the radial styloid intersected the position of the bicipital tuberosity. This was determined by the point where a perpendicular line from the bicipital tuberosity was drawn laterally to meet with the lateral line. We did this to establish if the PIN adopts its most lateral position on the radius at the same level as the bicipital tuberosity. RESULTS: The anterior safe zone in the approach to the biceps tuberosity extends approximately 15 mm from its prominence (mean, 20.7 mm; range, 16.0-24.1 mm). The PIN crosses the lateral midline from anterior to posterior at 46.0 mm (range, 31.2-67.0 mm) from the lateral epicondyle (lying directly opposite the bicipital tuberosity at nearly the same level); therefore, the drill exit should be posterior to lateral midline while aiming proximally to the bicipital tuberosity. CONCLUSION: Our anterior safe zone found that the PIN travels from an anterior position on the radius, when measuring 1 cm proximal to the bicipital tuberosity to a lateral position on the radius at the level of the bicipital tuberosity prominence (on the contralateral cortex), to a slightly more posterior position on the radius 1 cm distal to the bicipital tuberosity. Typically, the PIN sits directly opposite the biceps tuberosity, often directly on the cortex of the radius when the forearm is in full supination. CLINICAL RELEVANCE: Because of these findings, perpendicular bicortical drilling starting at the bicipital tuberosity should be avoided. A more proximal and ulnar drilling angle is recommended. Defining a safe zone for an anterior approach seems to be clinically unhelpful due to the high anatomical variability that exists for the position of the PIN around the proximal radius. Future studies could attempt to confirm our findings with the analysis of noncadaveric imaging in three different planes using such modalities as MRI to avoid the effects of tissue distortion during cadaveric preparation and dissection.

Simultaneous combined anterior and posterior approach for en bloc resection of sciatic notch sarcomas.

BACKGROUND: Monobloc resection of soft tissue sarcomas (STSs) has a major impact on overall survival and local recurrence. Anatomical boundaries, such as the sciatic notch, increase the risk of fragmentation of the lesion. To date there are few papers describing the optimal surgical technique to remove such STSs. The objective of this study is to describe a simultaneous anterior and posterior approach for resection of sciatic notch dumbbell tumours. CASE PRESENTATION: We present the surgical management of two patients diagnosed with well-differentiated liposarcomas of the sciatic notch with a retroperitoneal and gluteal extension in the two cases. Pre-operative diagnosis was made with a percutaneous biopsy including molecular analysis which demonstrated MDM2 amplification. We describe a simultaneous anterior and posterior approach, including the ligation of the posterior trunk of the internal iliac artery, to reduce intra-operative blood loss and devascularise the tumour. The anterior approach allows the evaluation of the tumour's retroperitoneal extension, release from its pelvic attachments and control of the surrounding neurovascular structures. During the posterior approach, bleeding is reduced by the devascularisation of the gluteal musculature achieved with internal iliac artery ligation. Clear margins were achieved in both cases. No vascular, skeletal or soft tissue reconstructions were required. CONCLUSIONS: Simultaneous combined anterior and posterior approaches to remove a malignant sciatic notch tumour optimises the chance of complete en bloc resection. This surgical strategy allows oncologic en bloc resection with minimal blood loss.

The utility and benefit of a newly established postgraduate training course in surgical exposures for orthopedic and trauma surgery.

INTRODUCTION: Limited data exist on specialty surgical cadaver courses for graduates, their skill gain, and whether the course contents are transferable to other surgical disciplines. AIM: We present the details on the establishment of a specialist trauma and orthopedics approach course, and explore educational and career outcomes from this program. METHODS: A 3-day surgical approach course was developed, including a dissection program utilizing Thiel embalmed cadavers. The course was accredited with the local orthopedics association. Participants were assessed by survey on acquired surgical knowledge, skill, decision-making, confidence, and on self-development and effect on career. RESULTS: Thirty-one participants successfully completed the courses over 3 years. Increases in surgical skill, knowledge, surgical decision-making and confidence were reported. Skills and confidence also positively impacted on other surgical disciplines. Courses rated highly for learning outcomes; comments highlighted usefulness, applicability, and practicing opportunities, while also impacting positively on career opportunities. CONCLUSION: Surgical courses have shown being useful for the acquisition of skills, knowledge, confidence and decision-making, with a positive impact on confidence and decision-making. This information is relevant to future participants, benefactors, surgical programs, and tertiary institutions who want to establish specialist surgical courses.