Adolescent idiopathic scoliosis is a three-dimensional deformity of the spine, affecting 1–3% of the population. Most cases are treated conservatively. Curves exceeding 45° in the thoracic spine and 40° in the lumbar spine may require correction and fusion surgery, to limit the progression of the curve and prevent restrictive pulmonary insufficiency (curves above 70°). When fusion is required, it may be performed either by posterior or anterior approaches. Posterior is useful for thoracic (Lenke I) curves, notably to correct the thoracic hypokyphosis frequently observed in AIS. Anterior approaches by thoraco-lombotomies allow an effective correction of thoraco-lumbar and lumbar curves (Lenke V and VI), with fewer levels fused than with posterior approaches. However, the approach requires diaphragm splitting and one may be concerned about the long-term pulmonary consequences. The literature provides conflicting insight regarding the consequences of the approach in anterior scoliosis correction, the interpretation of the results being difficult knowing that the correction of the scoliosis itself may improve pulmonary function. This is a retrospective observational study done at a Tertiary Institution. The HRQOL scores have been collected as a prospective cohort. Clinical and radiographic data was collected from patients charts and analysed by two senior surgeons. A cohort of 64 patients were operated in the given time period. 50 patients met the inclusion criteria. No major complications were reported. The Union rate was 100% and no post operative complications were noted. Pre and post SRS scores improved in all patients. The Anterior approach for Lenke V AIS gives great surgical exposure and allows for excellent correction of Cobb angle with minimal risk to the patient

Background. Over 35% of surgeons in the United States, and 10% in Canada use the direct anterior approach for primary total hip arthroplasty (THA). Some of the key barriers in its wider adoption are the learning curve and associated increased risk of adverse events. The purpose of this study was to determine the adoption rate as well as 90-day re-admission and adverse event of the anterior approach in a community-based hospital. Methods. From December 2015 to August 2018, two laterally based approach senior orthopaedic surgeons with over 20 years of practice performed 319 primary total hip replacements, with 164 being done through the anterior approach and 155 through the lateral approach. All but 8 of the anterior approaches were done on a regular operating table. Results. The anterior and lateral approach groups were comparable in age with mean 69.1+/− 10.2 and 68.9+/−9.3, respectively (p= 0.886), however the anterior group had patients with a statistically significantly lower BMI than the lateral group with mean 28.2+/−5.4 and 31.0+/−6.3, respectively (p < 0.001). Furthermore, there was a much lower percentage of females in the anterior group than in the lateral group with 49.4% and 65.2%, respectively (p= 0.004). It took surgeon A and B 12 and 24 months for the anterior approach to represent over 50% of their monthly cases, respectively. The anterior approach now accounts for approximately 80% of surgeon A's practice and 100% in surgeon B's practice in the last 6 and 18 months, respectively. Intraoperative adverse events were comparable between anterior and lateral approaches, with one incidence in each group (p= 0.968), however post-operative adverse events were more prevalent in the lateral group (n= 24) when compared to anterior group (n= 11) (p= 0.012). Further details of both approaches are provided in figure 1. Conclusion. Within a well-structured environment, the anterior approach can be safely introduced into a community-based practice. The progressive adoption of a new surgical technique combined with more experienced surgeon as a resource is an effective way that requires further study. For any figures or tables, please contact the authors directly

Aims. There is evidence that morbidly obese patients have more intra- and postoperative complications and poorer outcomes when undergoing total hip arthroplasty (THA) with the direct anterior approach (DAA). The aim of this study was to determine the efficacy of DAA for THA, and compare the complications and outcomes of morbidly obese patients with nonobese patients. Methods. Morbidly obese patients (n = 86), with BMI ≥ 40 kg/m. 2. who underwent DAA THA at our institution between September 2010 and December 2017, were matched to 172 patients with BMI < 30 kg/m. 2. Data regarding demographics, set-up and operating time, blood loss, radiological assessment, Harris Hip Score (HHS), International Hip Outcome Tool (12-items), reoperation rate, and complications at two years postoperatively were retrospectively analyzed. Results. No significant differences in blood loss, intra- and postoperative complications, or implant position were observed between the two groups. Superficial wound infection rate was higher in the obese group (8.1%) compared to the nonobese group (1.2%) (p = 0.007) and relative risk of reoperation was 2.59 (95% confidence interval 0.68 to 9.91). One periprosthetic joint infection was reported in the obese group. Set-up time in the operating table and mean operating time were higher in morbidly obese patients. Functional outcomes and patient-related outcome measurements were superior in the obese group (mean increase of HHS was 52.19 (SD 5.95) vs 45.1 (SD 4.42); p < 0.001), and mean increase of International Hip Outcome Tool (12-items) was 56.8 (SD 8.88) versus 55.2 (SD 5.85); p = 0.041). Conclusion. Our results suggest that THA in morbidly obese patients can be safely and effectively performed via the DAA by experienced surgeons. Cite this article: Bone Jt Open 2022;3(1):4–11

Our unit historically performed total hip replacement (THR) through either posterior or anterolateral approaches. In November 2020 a group of 5 consultants transitioned to utilising the Direct Anterior Approach (DAA). Appropriate training was undertaken and cases were performed as dual consultant procedures with intraoperative radiography or robotic assistance. Outcomes were collated prospectively. These included basic demographics, intraoperative details, complication rates and Oxford Hip Scores. A total of 48 patients underwent DAA THR over 1 year. Mean age was 67 and ASA 2. Over this time period 140 posterior approach and 137 anterolateral approach THR's were performed with available data. Propensity score matching was performed on a 1:1 basis using BMI, Age, Sex and ASA as covariates to generate a matched cohort group of conventional approach THR (n=37). Length of stay was significantly reduced at 1.95 days (p<0.001) with DAA compared to Anterolateral and Posterior approach. There was no significant difference with length of surgery, blood loss, Infection, dislocation and periprosthetic fracture rate. There was no significant difference in Oxford Hip Score between any approach at 3 months or 1 year. The transition to this approach has not made a negative impact despite its associated steep learning curve, and has improved efficiency in elective surgery. From our experience we would suggest those changing to this approach receive appropriate training in a high-volume centre, and perform cases as dual consultant procedures

Psoas tendinopathy is a potential cause of groin pain after primary total hip arthroplasty (THA). The direct anterior approach (DAA) is becoming increasingly popular as the standard approach for primary THA due to being a muscle preserving technique. It is unclear what the prevalence is for the development of psoas-related pain after DAA THA, how this can influence patient reported outcome, and which risk factors can be identified. This retrospective case control study of prospectively recorded data evaluated 1784 patients who underwent 2087 primary DAA THA procedures between January 2017 and September 2019. Psoas tendinopathy was defined as (1) persistence of groin pain after DAA THA and was triggered by active hip flexion, (2) exclusion of other causes such as dislocation, infection, implant loosening or (occult) fractures, and (3) a positive response to an image-guided injection with xylocaine and steroid into the psoas tendon sheath. Complication-, re-operation rates, and patient-reported outcome measures (PROMs) were measured. Forty-three patients (45 hips; 2.2%) were diagnosed with psoas tendinopathy according to the above-described criteria. The mean age of patients who developed psoas tendinopathy was 50.8±11.7 years, which was significantly lower than the mean age of patients without psoas pain (62.4±12.7y; p<0.001). Patients with primary hip osteoarthritis were significantly less likely to develop psoas tendinopathy (14/1207; 1.2%) in comparison to patients with secondary hip osteoarthritis to dysplasia (18/501; 3.6%) (p<0.001) or FAI (12/305; 3.9%) (p<0.001). Patients with psoas tendinopathy had significantly lower PROM scores at 6 weeks and 1 year follow-up. Psoas tendinopathy was present in 2.2% after DAA THA. Younger age and secondary osteoarthritis due to dysplasia or FAI were risk factors for the development of psoas tendinopathy. Post-operatively, patients with psoas tendinopathy often also presented with low back pain and lateral trochanteric pain. Psoas tendinopathy had an important influence on the evolution of PROM scores

Short cementless femoral stems are increasingly popular as they allow for less dissection for insertion. Use of such stems with the anterior approach (AA) may be associated with considerable per-operative fracture risk. This study's primary aim was to evaluate whether patient-specific femoral- and pelvic- morphology and surgical technique, influence per-operative fracture risk. In doing so, we aimed to describe important anatomical thresholds alerting surgeons. This is a single-center, multi-surgeon retrospective, case-control matched study. Of 1145 primary THAs with a short, cementless stem inserted via the AA, 39 periprosthetic fractures (3.4%) were identified. These were matched for factors known to increase fracture risk (age, gender, BMI, side, Dorr classification, stem offset and indication for surgery) with 78 THAs that did not sustain a fracture. Radiographic analysis was performed using validated software to measure femoral- (canal flare index [CFI], morphological cortical index [MCI], calcar-calcar ratio [CCR]) and pelvic- (Ilium-ischial ratio [IIR], ilium overhang, and ASIS to greater trochanter distance) morphologies and surgical technique (% canal fill). Multivariate and Receiver-Operator Curve (ROC) analysis was performed to identify predictors of fracture. Femoral factors that differed included CFI (3.7±0.6 vs 2.9±0.4, p3.17 and II ratio>3 (OR:29.2 95%CI: 9.5–89.9, p<0.001). Patient-specific anatomical parameters are important predictors of fracture-risk. When considering the use of short stems via the AA, careful radiographic analysis would help identify those at risk in order to consider alternative stem options

INTRODUCTION. Proponents of the THA anterior approach have advocated for the use of dedicated surgical tables similar to those used in lower extremity fracture care that allow for traction, rotation, and angulation of the limb during surgery. Some tables require a specially-trained assistant to manipulate the table, whereas some may be manipulated by the surgeon. The purpose of this study is to compare the clinical outcomes in patients who underwent THA through an anterior approach on an assistant-controlled (AC) versus a surgeon-controlled (SC) table. METHODS. This is a retrospective study of 343 consecutive THA patients from January 2017 – October 2017. Surgical and clinical data included surgical time, LOS, presence of pain (groin, hip, or thigh pain) at latest follow-up, and revision for any reason. Immediate postoperative radiographs were compared with latest follow-up radiographs to assess for LLD, stem alignment, and stem subsidence. RESULTS. 167 (48.7%) cases were performed using the AC table, and 176 (51.3%) were performed using the SC table. Overall, surgical time was significantly greater for surgeries which utilized the self-controlled table (70.2 minutes vs. 66.1 minutes, respectively). There was a statistically significant difference between the first and last third of cases performed on the SC table (73.6 minutes vs. 68.0 minutes, respectively). There were no significant differences in any clinical or radiographic outcomes. DISCUSSION. Surgeons who routinely perform an anterior approach for THA can expect similar outcomes using an SC table as opposed to an AC table. Although surgical time with the SC table was longer by approximately four minutes, this difference is not clinically significant. In addition, surgical time with the SC table may be decreased following an initial learning curve. The SC table allows for greater surgeon control during the procedure and a significantly smaller institutional financial investment due to the reduced manpower required

Introduction. The limited field of view with less-invasive hip approaches for total hip arthroplasty can make a reliable cup positioning more challenging. The aim of this study was to evaluate the accuracy of cup placement between the traditional transgluteal approach and the anterior approach in a routine setting. Objectives. We asked if the (1) accuracy, (2) precision, and (3) number of outliers of the prosthetic cup orientation differed between three study groups: the anterior approach in supine position, the anterior approach in lateral decubitus position, and the transgluteal approach in lateral decubitus position. Methods. In a retrospective comparative study we compared the inclination and anteversion of the cup after total hip arthroplasty (THA) in a consecutive series of 325 patients (350 hips). The transgluteal approach group consisted of 67 hips operated in lateral decubitus position; the anterior approach in supine position consisted of 127 operated and the anterior approach in lateral decubitus position consisted of 156 hips. The aim of the cup orientation was Lewinnek's safe zone defined by an inclination of 40±10° and an anteversion of 15°±10°. The postoperative cup orientation was determined using a validated computer-assisted method based on statistical shape modeling. This method allows the virtual creation of an accurate three-dimensional pelvic model for each individual patient based on the two-dimensional anteroposterior pelvic radiograph. The inclination and anteversion was then calculated relative to the anterior pelvic plane – a natural reference plane for the calculation of inclination and anteversion. Accuracy was defined as the difference from the cup orientation to Lewinnek's target value. Precision was defined as the standard deviation of the two angles. Outliers were characterized by an anteversion or inclination angle outside of Lewinnek's safe zone. Results. (1) The accuracy of the anterior approach in supine position did not differ compared to the transgluteal approach, but differed to the anterior approach in supine position for inclination (p=0.882; p<0.001) (Figure 1) and anteversion (p = 0.014; p<0.001) (Figure 2). (2) The precision of the anterior approach in supine position was significantly higher compared to the transgluteal approach (p<0.001) and the anterior approach in lateral decubitus position for anteversion (p<0.001 for both groups) and inclination (p<0.001 for both groups) (Figure 3). (3) There was a significantly reduced number of outliers for the anterior approach in supine position compared to the anterior approach in lateral position (p=0.001) but not in comparison to the transgluteal approach (p=0.999) (Figure 2). Conclusions. The anterior approach in supine position results in a more precise placement of the prosthetic cup both for inclination and anteversion. Cup placement with less-invasive approaches does not lead to a higher variability of cup placement despite the more limited surgical field of view. For any figures or tables, please contact authors directly (see Info & Metrics tab above).

Introduction. Cemented femoral fixation has been shown to carry a lower risk of peri-prosthetic fracture (PPF). The aim of this study was to determine whether adequate (1) stem position and (2) cement mantle (i.e. factors associated with outcome of cemented stems) can be achieved with the anterior approach as compared to the posterior approach. Methods. This is a prospective, multi-surgeon, single center, consecutive, case-matched series. Twenty patients/hips (age: 76±SD 14) that underwent cemented fixation of their femoral component via an anterior approach (AA) were matched with twenty hips that received the same cemented femoral components via the posterior approach by the same surgeons. Outcome measures of interest included Barrack classification (A, B, C or D), Coronal alignment defined as Varus (>5º), mild varus (3–5º), neutral, mild valgus (3–5º) and valgus (>5º) of the stem and sagittal component alignment defined as anterior to posterior, neutral, posterior to anterior (±3 degrees) and cement mantle thickness in all Gruen zones. Results. There was no difference between groups in the Barrack classification (DAA: A:12,B:7, D:1); (Posterior: A:13, B:7) [p=0.56]. Coronal alignment (DAA: 15 neutral, 5 mild varus/valgus); (Post:15 neutral, 3 mild varus/valgus, 2 valgus) [p=0.27] and sagittal alignment was similar between groups [p=0.07]. Cement mantle thickness per Gruen zone was also similar between groups in all zones with particular interest zones 8 [P=0.68] and 12 [p=0.3] confirming comparable sagittal cement mantle thickness. Conclusion. This study demonstrates that equivalent stem alignment and cement mantle quality can be achieved with both approaches. As such, patients undergoing the AA approach can benefit from a quick recovery and lower risk of peri-prosthetic femur fracture

The purpose of this study was to report all complications during the first consecutive 865 cases of bikini incision direct anterior approach (DAA) total hip arthroplasty (THA) performed by a single surgeon. The secondary aims of the study are to report our clinical outcomes and implant survivorship. We discuss our surgical technique to minimize complication rates during the procedure. We undertook a retrospective analysis of our complications, clinical outcomes and implant survivorship of 865 DAA THA's over a period of 6 years (mean = 5.1yrs from 2.9 to 9.4 years). The complication rates identified in this study were low. Medium term survival at minimum 2-year survival and revision as the end point, was 99.53% and 99.84% for the stem and acetabular components respectively. Womac score improved from 49 (range 40-58) preoperatively to 3.5(range 0-8.8) and similarly, HHS scores improved from 53(range 40-56) to 92.5(range 63-100) at final follow-up (mean = 5.1 yrs) when compared to preoperative scores. These results suggest that bikini incision DAA technique can be safely utilised to perform THA

The approach to total hip arthroplasty (THA) should allow adequate visualization and access so as to implant in optimal position whilst minimizing muscle injury, maintaining or restoring normal soft tissue anatomy and biomechanics and encouraging a rapid recovery with minimal complications. Every surgeon who performs primary hip arthroplasties will expound the particular virtues of his or her particular routine surgical approach. Usually this approach will be the one to which the surgeon was most widely exposed to during residency training. There is a strong drive from patients, industry, surgeon marketing campaigns, and the media to perform THA through smaller incisions with quicker recoveries. The perceived advantage of the anterior approach is the lack of disturbance of the soft tissues surrounding the hip joint, less pain, faster recovery with the potential for earlier return to work, shorter hospital stay and improved cosmetic results. The potential disadvantages include less visibility, longer operation time, nerve injuries, femoral fractures, malposition and a long learning curve for the surgeon (and his / her patients). The anterior approach was first performed in Paris, by Robert Judet in 1947. The advantages of the anterior approach for THA are several. First, the hip is an anterior joint, closer to the skin anterior than posterior. Second, the approach follows the anatomic interval between the zones of innervation of the superior and inferior gluteal nerves lateral and the femoral nerve medial. Third, the approach exposes the hip without detachment of muscle from the bone. The mini-incision variation of this exposure was developed by Joel Matta in 1996. He rethought his approach to THA and his goals were: lower risk of dislocation, enhanced recovery, and increased accuracy of hip prosthesis placement and leg length equality. This approach preserves posterior structures that are important for preventing dislocation while preserving important muscle attachments to the greater trochanter. The lack of disturbance of the gluteus minimus and gluteus medius insertions facilitates gait recovery and rehabilitation, while the posterior rotators and capsule provide active and passive stability and account for immediate stability of the hip and a low risk of dislocation. A disadvantage of the approach is the fact that a special operating table with traction is required. Potential complications include intraoperative femoral and ankle fractures. These can be avoided through careful manipulation of the limb. If a femoral fracture occurs, the incision can be extended distally by lengthening the skin incision downward along the anterolateral aspect of the thigh, and splitting the interval between the rectus femoris and the vastus lateralis. The choice of approach used to perform a primary THA remains controversial. The primary goals are pain relief, functional recovery and implant longevity performed with a safe and reproducible approach without complications. The anterior approach is promising in terms of hospital stay and functional recovery. Although recent studies suggest that component placement in minimally invasive surgery is safe and reliable, no long-term results have been published. Further follow-up and development is necessary to compare the results with the posterior approach as most of the positive data is based on comparisons with the anterolateral approach. The proposed benefits of the anterior approach are not supported by the current available literature. The issues regarding the difficult learning curve, rate of complications, operative time, requirement for trauma tables and image intensifier should be taken into account by surgeons starting with the anterior approach in THA

Periprosthetic femoral fracture (PFF) following primary total hip arthroplasty (THA) is of raising concern with the aging of the population. The aim of this retrospective study was to assess the incidence of early PFF associated with Charnley- Kerboull (CK) stems cemented line-to-line according to the “French paradox” principles through the anterior approach (AA) in patients older than 70 years old. This monocentric study involved 25 surgeons with various level of experience. From a prospectively collected database, all CK stems (AmisK®, Medacta, Castel San Pietro, Switzerland) done consecutively from January 2018 to May 2022 through the AA in patients older than 70 years were included. The measured parameters included canal flare index (CFI), morphological cortical index (MCI), canal-calcar ratio (CCR), ilium-ischial ratio (IIR), ilium overhang, and anterior superior iliac spine (ASIS) to greater trochanter distance. Dorr classification was also recorded. A total of 416 CK stems performed by 25 surgeons were included. All patients had a minimal 3-month follow-up. The mean age was 77.4 years, and the mean BMI was 25.3 kg/m. 2. According to the Dorr classification 240 hips were of Dorr type A, 144 Dorr type B, and 2 Dorr type C. Mean CFI, MCI, CCR, IIR and ASIS-GT were 3.8, 0.5, 2.8, 2.5, and 101mm, respectively. Amongst the 416 THAs, one (0.24%; 95% CI 0.20 – 0.28%) early PFF Vancouver type B2 fracture that occurred 24 days postoperatively was observed. This study demonstrated that CK stems cemented according to the “French Paradox” were associated with an extremely low rate of early PFF in patients over 70 years. The observed results are better than those reported with uncemented or taper slip cemented stems. Longer follow-up is warranted to evaluate further rate of fracture that may occur during the bone remodeling process around the femoral component

The approach to total hip arthroplasty (THA) should allow adequate visualization and access so as to implant in optimal position whilst minimizing muscle injury, maintaining or restoring normal soft tissue anatomy and biomechanics and encouraging a rapid recovery with minimal complications. The direct anterior approach (DAA) for THA was first performed in Paris, by Robert Judet in 1947. This procedure has since been performed consistently by a small group of surgeons and has recently gained great popularity. Access to the hip can be safely performed with one or two assistants. The advantages of the anterior approach for hip arthroplasty are several. First, the hip is an anterior joint, closer to the skin anterior than posterior. Second, the approach follows the anatomic interval between the zones of innervation of the superior and inferior gluteal nerves lateral and the femoral nerve medial. Third, the approach exposes the hip without detachment of muscle from the bone. Care must be taken to avoid cutting the lateral femoral cutaneous nerve which runs over the fascia of the sartorius. The mini-incision variation of this exposure was developed by Joel Matta in 1996. He rethought his approach to hip arthroplasty and by abandoning the posterior approach and adopting the anterior approach his goals were: lower risk of dislocation, enhanced recovery, and increased accuracy of hip prosthesis placement and leg length equality. This approach preserves posterior structures that are important for preventing dislocation while preserving important muscle attachments to the greater trochanter. The lack of disturbance of the gluteus minimus and gluteus medius insertions facilitates gait recovery and rehabilitation while the posterior rotators and capsule provides active and passive stability and accounts for immediate stability of the hip and a low risk of dislocation. Using the anterior approach, patients are allowed to mobilise their hip freely. The gluteus maximus and tensor fascia latae muscles insert on the iliotibial band which joins them and form a ´hip deltoid´. Lack of disturbance of these abductors and pelvic stabilisers is another benefit of the anterior approach and accelerates gait recovery. The lateral femoral cutaneous nerve is at risk when the fascia is incised between the tensor fascia latae and the sartorius muscle. Damaging it may lead to a diminished sensation on the lateral aspect of the thigh and formation of a neuroma. A disadvantage of the approach is the fact that a special operating table with traction is required. Potential complications include intra-operative femoral and ankle fractures. These can be avoided through careful manipulation of the limb. If a femoral fracture occurs, the incision can be extended distally along the anterolateral aspect of the thigh, and splitting the interval between the rectus femoris and the vastus lateralis. In obese or muscular patients, where visibility is in doubt, an increase of the incision length will give the surgeon the required view. The choice of approach used to perform a primary THA remains controversial. The primary goal of a hip replacement is pain relief, functional recovery and implant longevity performed with a safe and reproducible approach without complications. The anterior approach is promising in terms of hospital stay and functional recovery. Although recent studies suggest that component placement in minimally invasive surgery is safe and reliable, no long-term results have been published. Further follow-up and development is necessary to compare the results with the posterior approach. The proposed benefits of with the DAA are not supported by the current available literature. The issues regarding the difficult learning curve, rate of complications, operative time, requirement for trauma tables and image intensifier should be taken into account by surgeons starting with the DAA in THA

Introduction. In total hip arthroplasty, correct sizing is critical for fixation and longevity of cementless components. Previously, three-dimensional CT templating has been shown to be more accurate than using 2D radiographs. The accuracy of the Optimized Positioning System (OPS. TM. ) planning software has not been reported. The aim of this study was to measure the accuracy of the OPS planning software in predicting the implanted acetabular cup and femoral stem size when used with the direct anterior approach. Method. Between October 2018 and March 2019, 95 patients received a bone preserving cementless MiniHip stem (Corin, UK). Sixty-three of these patients also received a cementless Trinity cup (Corin, UK). All patients were sent for OPS. TM. pre-operative planning, a patient-specific dynamic modelling software used to determine the optimal acetabular and femoral component size and positions. Average age was 57 (28 to 78) and 44% were female. All cases were performed using the direct anterior approach. The sizes of implants used were retrospectively compared to the planned OPS. TM. sizes. Results. Of the 95 cases, 98% (n=93) of MiniHip stems were within one size of that predicted, and 66% (n=63) matched exactly the predicted size. Of the 63 Trinity cups, 98% (n=62) were within one size of that predicted and 48% (n=30) matched exactly the predicted size. All stems and cups were within 2 sizes of plan [Fig. 1]. Conclusion. The OPS. TM. planning software successfully predicted more than 95% of implanted cup and stems within one size, with 100% implants being within 2 sizes. There is significant value in accurately predicting implant sizes preoperatively, both as an indicator to the surgeon as to the size expected, and for reducing the inventory supplied to the hospitals. For any figures or tables, please contact the authors directly

Abstract. Objectives. Non-technical skills including teamwork play a pivotal role in surgical outcomes. Virtual reality is effective at improving technical skills, however there is a paucity of evidence on team-based virtual reality (VR) training. This study aimed to assess if multiplayer virtual reality training was superior to solo training for acquisition of both technical and non-technical skills in learning the complex anterior approach total hip arthroplasty operation. Methods. 10 novice surgeons and 10 novice scrub nurses, were randomised to solo or team virtual reality training to perform anterior approach total hip arthroplasty. Solo participants trained with virtual avatar counterparts, whilst teams trained in pairs (surgeon and scrub nurse). Both groups underwent 5 VR training sessions over 6 weeks. Then, they underwent a real-life assessment in which they performed AA-THA on a high-fidelity model with real equipment in a simulated operating theatre. Teams performed together and solo participants were randomly paired up with a solo player of the opposite role. Videos of the assessment were marked by two blinded expert assessors. Outcomes were procedure time, procedural errors from an expert pre-defined protocol and acetabular component positioning. Non-technical skills were assessed using the NOTECHs II and NOTSS scores. Results. Teams were 28.11% faster than solos in the real world assessment (31.22 minutes ±2.02 vs 43.43 ±2.71, p=0.01), with 34.91% less errors (−15.25 errors ±3.09 vs −23.43 ±1.84, p=0.04). Teams had significantly higher NOTSS and NOTECHS II scores when compared to solos (p<0.001). 8/10 surgeons placed the acetabular component within the target safe zone. Conclusions. Multiplayer training appears to lead to faster surgery with fewer technical errors and the development of superior non-technical skills. VR learnt skills appear to translate to the physical world. This supports the application of multidisciplinary learning to create a more integrated approach to surgical team training

INTRODUCTION. The direct anterior approach (DAA) for total hip arthroplasty has become a popular technique. Proponents of the anterior approach cite advantages such as less muscle damage, lower dislocation risk, faster recovery, and more accurate implant placement for the approach. However, there is a steep, complex learning curve associated with the technique. The present study seeks to define the learning curve based on individual surgical and outcome variables for a high-volume surgeon. METHODS. 300 consecutive patients were retrospectively analyzed. Intraoperative outcomes measured include surgery time and estimated blood loss (EBL). Complications include intraoperative fracture, post-operative fracture, infection, dislocation, leg length discrepancy, loosening, and medical complications such as deep vein thrombosis (DVT) and pulmonary embolism (PE). Segmented regression models were used to elucidate the presence of a learning curve and mastery of the procedure with regard to each individual variable. RESULTS. The mean operative time was 77.1 minutes (range 40–213). Operative time improved at a rate of 6.6 minutes per case for the first 15 cases then by an average of 5 seconds per subsequent case. The mean EBL for the series was 288.6 mL. Segmented regression shows EBL decreased at a rapid rate until case 52, followed by a more gradual decline. Complications were higher in the first 7 surgeries, with a 48% decrease in the likelihood of complication with each subsequent surgery. The improvement continued through the rest of the series with a 0.5% decrease in likelihood with each surgery. DISCUSSION. Our data contributes to the current body of literature by defining the learning curve with what we consider the most pertinent outcomes. First, we show that operative efficiency can be gained quite quickly (15 cases) while the slower improvement in EBL demonstrates continued learning about the anatomy. Our data is consistent with previous published reports regarding complication improvement. The present study will provide surgeons considering DAA useful information regarding what to expect during their learning curve. Furthermore, the data can be useful for surgeons charged with teaching the technique to critically evaluate what learning curve variables can be improved to hasten the learning curve

The direct anterior approach (DAA) is a popular minimally invasive approach for total hip arthroplasty (THA). It usually involves ligation of the lateral femoral circumflex artery's ascending branch (a-LFCA), which contributes to the perfusion of the tensor fasciae latae (TFL) muscle. Periarticular muscle status and clinical outcome were assessed after DAA-THA after a-LFCA preservation versus ligation. We evaluated surgical records of 161 patients undergoing DAA-THA with tentative preservation of the a-LFCA by the senior author between May and November 2021. Among 92 eligible patients, 33 (35 hips) featured successful preservation, of which 20 (22 hips, 13 female) participated in the study. From 59 patients with ligated a-LFCA, 26 (27 hips, 15 female) were enrolled, constituting the control group. MRI and clinical examinations were performed at 17–26 months to analyze volume and fatty infiltration of the TFL, gluteus medius and gluteus minimus muscles relative to the contralateral non-THA hip (15 preserved, 18 ligated). Clinical and radiographic data was retrospectively extracted from patient files. Patient-reported outcomes (PROMs) were added from the THA registry. There was a relative difference in TFL muscle volume of -6.27 cm. 3. (−9.89%, p=0.018) after a-LFCA preservation versus -8.6 cm. 3. (=11.62%, p=0.002) after ligation, without group differences (p>0.340). a-LFCA preservation showed lower relative TFL fatty infiltration (p=0.10). Gluteal muscle status was similar between sides and groups. Coxa valga morphology was more frequent in a-LFCA preservation (83%) than ligation (17%). Clinical outcomes showed high patient satisfaction in both groups, without difference in PROMs, but less anterolateral soft-tissue swelling after a-LFCA preservation (p<0.001). Despite excellent clinical results in both groups, preservation of the a-LFCA was associated with less TFL fatty infiltration and soft tissue swelling. Provided there is no compromise of intraoperative access we recommend a-LFCA preservation for DAA-THA

Anterior approach total hip arthroplasty (AA-THA) has a steep learning curve, with higher complication rates in initial cases. Proper surgical case selection during the learning curve can reduce early risk. This study aims to identify patient and radiographic factors associated with AA-THA difficulty using Machine Learning (ML). Consecutive primary AA-THA patients from two centres, operated by two expert surgeons, were enrolled (excluding patients with prior hip surgery and first 100 cases per surgeon). K- means prototype clustering – an unsupervised ML algorithm – was used with two variables - operative duration and surgical complications within 6 weeks - to cluster operations into difficult or standard groups. Radiographic measurements (neck shaft angle, offset, LCEA, inter-teardrop distance, Tonnis grade) were measured by two independent observers. These factors, alongside patient factors (BMI, age, sex, laterality) were employed in a multivariate logistic regression analysis and used for k-means clustering. Significant continuous variables were investigated for predictive accuracy using Receiver Operator Characteristics (ROC). Out of 328 THAs analyzed, 130 (40%) were classified as difficult and 198 (60%) as standard. Difficult group had a mean operative time of 106mins (range 99–116) with 2 complications, while standard group had a mean operative time of 77mins (range 69–86) with 0 complications. Decreasing inter-teardrop distance (odds ratio [OR] 0.97, 95% confidence interval [CI] 0.95–0.99, p = 0.03) and right-sided operations (OR 1.73, 95% CI 1.10–2.72, p = 0.02) were associated with operative difficulty. However, ROC analysis showed poor predictive accuracy for these factors alone, with area under the curve of 0.56. Inter-observer reliability was reported as excellent (ICC >0.7). Right-sided hips (for right-hand dominant surgeons) and decreasing inter-teardrop distance were associated with case difficulty in AA-THA. These data could guide case selection during the learning phase. A larger dataset with more complications may reveal further factors

For learning any new technique the main principle to follow is: learn the technique thoroughly from start to finish and adopt it as taught, without attempting to modify it until you are very familiar with it. Orthopaedic table enhanced anterior approach THA (ATHA) is at this point a well-established teachable and repeatable technique though its safety and efficacy depends on adherence to details. These technical details have evolved to become part of the technique since I first taught it at a course in 2003. The technical details and innovations have utilised the invaluable input from high volume expert surgeons as well as from less experienced surgeons taking on the challenges of learning. Considering anterior approach (AA), three technical aspects can be a “mental block” for the uninitiated surgeon: 1) supine position, 2) the orthopaedic table, 3) checking cup position, leg length and offset with the image intensifier/C-arm. Keep in mind that though you may have been initially trained and experienced with lateral position, a flat table and no x-ray checks, these three technical aspects greatly facilitate Anterior Approach and enhance its repeatability, safety, accuracy and overall “ease of use”. Anterior approach technical instruction is available at a number of venues and the preceding is consistent with the surgeon developed technique taught at courses. Visiting a surgeon who is expert in AA can also provide an effective supplemental educational experience

Short cementless femoral stems are increasingly popular as they allow for less dissection for insertion. Use of such stems with the anterior approach (AA) may be associated with considerable per-operative fracture risk. This study's primary aim was to evaluate whether patient-specific femoral- and pelvic- morphology and surgical technique, influence per-operative fracture risk. In doing so, we aimed to describe important anatomical thresholds alerting surgeons. This is a single-centre, multi-surgeon retrospective, case-control matched study. Of 1145 primary THAs with a short, cementless stem inserted via the AA, 39 periprosthetic fractures (3.4%) were identified. These were matched for factors known to increase fracture risk (age, gender, BMI, side, Dorr classification, stem offset and indication for surgery) with 78 THAs that did not sustain a fracture. Radiographic analysis was performed using validated software to measure femoral- (canal flare index [CFI], morphological cortical index [MCI], calcar-calcar ratio [CCR]) and pelvic- (Ilium-ischial ratio [IIR], ilium overhang, and ASIS to greater trochanter distance) morphologies and surgical technique (% canal fill). Multivariate and Receiver-Operator Curve (ROC) analysis was performed to identify predictors of fracture. Femoral factors that differed included CFI (3.7±0.6 vs 2.9±0.4, p<0.001) and CCR (0.5±0.1 vs 0.4±0.1, p=0.006). The mean IIR was higher in fracture cases (3.3±0.6 vs 3.0±0.5, p<0.001). % Canal fill was reduced in fracture cases (82.8±7.6 vs 86.7±6.8, p=0.007). Multivariate analysis and ROC analyses revealed a threshold CFI of 3.17 was predictive of fracture (sensitivity:84.6% / specificity:75.6%). Fracture risk was 29 times higher when patients had CFI>3.17 and II ratio>3 (OR:29.2 95%CI: 9.5–89.9, p<0.001). Patient-specific anatomical parameters are important predictors of fracture-risk. When considering the use of short stems via the AA, careful radiographic analysis would help identify those at risk in order to consider alternative stem options