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

Aims. Surgical approaches that claim to be minimally invasive, such as the direct anterior approach (DAA), are reported to have a clinical advantage, but are technically challenging and may create more injury to the soft-tissues during joint exposure. Our aim was to quantify the effect of soft-tissue releases on the joint torque and femoral mobility during joint exposure for hip resurfacing performed via the DAA. Methods. Nine fresh-frozen hip joints from five pelvis to mid-tibia cadaveric specimens were approached using the DAA. A custom fixture consisting of a six-axis force/torque sensor and motion sensor was attached to tibial diaphysis to measure manually applied torques and joint angles by the surgeon. Following dislocation, the torques generated to visualize the acetabulum and proximal femur were assessed after sequential release of the joint capsule and short external rotators. Results. Following initial exposure, the ischiofemoral ligament (7 to 8 o’clock) was the largest restrictor of exposure of the acetabulum, contributing to a mean 25% of overall external rotational restraint. The ischiofemoral ligament (10 to 12 o’clock) was the largest restrictor of exposure of the proximal femur, contributing to 25% of overall extension restraint. Releasing the short external rotators had minimal contribution in torque generated during joint exposure (≤ 5%). Conclusion. Adequate exposure of both proximal femur and acetabulum may be achieved with minimal torque by performing a full proximal circumferential capsulotomy while preserving short external rotators. The joint torque generated and exposure achieved is dependent on patient factors; therefore, some cases may necessitate further releases. Cite this article: Bone Joint J 2024;106-B(3 Supple A):59–66

Aims. It is not known whether preservation of the capsule of the hip positively affects patient-reported outcome measures (PROMs) in total hip arthroplasty using the direct anterior approach (DAA-THA). A recent randomized controlled trial found no clinically significant difference at one year postoperatively. This study aimed to determine whether preservation of the anterolateral capsule and anatomical closure improve the outcome and revision rate, when compared with resection of the anterolateral capsule, at two years postoperatively. Methods. Two consecutive groups of patients whose operations were performed by the senior author were compared. The anterolateral capsule was resected in the first group of 430 patients between January 2012 and December 2014, and preserved and anatomically closed in the second group of 450 patients between July 2015 and December 2017. There were no other technical changes between the two groups. Patient characteristics, the Charlson Comorbidity Index (CCI), and surgical data were collected from our database. PROM questionnaires, consisting of the Oxford Hip Score (OHS) and Core Outcome Measures Index (COMI-Hip), were collected two years postoperatively. Data were analyzed with generalized multiple regression analysis. Results. The characteristics, CCI, operating time, and length of stay were similar in both groups. There was significantly less blood loss in the capsular preservation group (p = 0.037). The revision rate (n = 3, (0.6%) in the resected group, and 1 (0.2%) in the preserved group) did not differ significantly (p = 0.295). Once adjusted for demographic and surgical factors, the preserved group had significantly worse PROMs: + 0.24 COMI-Hip (p < 0.001) and -1.6 OHS points (p = 0.017). However, the effect sizes were much smaller than the minimal clinically important differences (MCIDs) of 0.95 and 5, respectively). The date of surgery (influencing, for instance, the surgeon’s age) was not a significant factor. Conclusion. Based on the MCID, the lower PROMs in the capsular preservation group do not seem to have clinical relevance. They do not, however, confirm the expected benefit of capsular preservation reported for the posterolateral approach. Cite this article: Bone Joint J 2022;104-B(7):826–832

Aims. Lateral femoral cutaneous nerve (LFCN) injury is a potential complication after the direct anterior approach for total hip arthroplasty (DAA-THA). The aim of this study was to determine how the location of the fasciotomy in DAA-THA affects LFCN injury. Methods. In this trial, 134 patients were randomized into a lateral fasciotomy (n = 67) or a conventional fasciotomy (n = 67) group. This study was a dual-centre, double-blind, prospective randomized controlled two-arm trial with parallel group design and a 1:1 allocation ratio. The primary endpoint was the presence of LFCN injury, which was determined by the presence of numbness, decreased sensation, tingling, jolt-like sensation, or pain over the lateral aspect of the thigh, excluding the surgical scar, using a patient-based questionnaire. The secondary endpoints were patient-reported outcome measures (PROMs) using the Western Ontario and McMaster Universities osteoarthritis index (WOMAC), Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire (JHEQ), and the Forgotten Joint Score-12 (FJS-12). Assessments were obtained three months after surgery. Results. The incidence of LFCN injury tended to be lower in the lateral fasciotomy group (p = 0.089). In the lateral fasciotomy group, there were no significant differences in the mean PROM scores between patients with and without LFCN injury (FJS-12: 54.42 (SD 15.77) vs 65.06 (SD 26.14); p = 0.074; JHEQ: 55.21 (SD 12.10) vs 59.72 (SD 16.50); p = 0.288; WOMAC: 82.45 (SD 6.84) vs 84.40 (SD 17.91); p = 0.728). In the conventional fasciotomy group, there were significant differences in FJS-12 and JHEQ between patients with and without LFCN injury (FJS-12: 43.21 (SD 23.08) vs 67.28 (SD 20.47); p < 0.001; JHEQ: 49.52 (SD 13.97) vs 59.59 (SD 15.18); p = 0.012); however, there was no significant difference in WOMAC (76.63 (SD 16.81) vs 84.16 (SD 15.94); p = 0.107). Conclusion. The incidence of LFCN injury at three months after THA was comparable between the lateral and conventional fasciotomy groups. Further studies are needed to assess the long-term effects of these approaches. Cite this article: Bone Joint J 2023;105-B(12):1252–1258

Aims. The most effective surgical approach for total hip arthroplasty (THA) remains controversial. The direct anterior approach may be associated with a reduced risk of dislocation, faster recovery, reduced pain and fewer surgical complications. This systematic review aims to evaluate the current evidence for the use of this approach in THA. Materials and Methods. Following the Cochrane collaboration, an extensive literature search of PubMed, Medline, Embase and OvidSP was conducted. Randomised controlled trials, comparative studies, and cohort studies were included. Outcomes included the length of the incision, blood loss, operating time, length of stay, complications, and gait analysis. Results. A total of 42 studies met the inclusion criteria. Most were of medium to low quality. There was no difference between the direct anterior, anterolateral or posterior approaches with regards to length of stay and gait analysis. Papers comparing the length of the incision found similar lengths compared with the lateral approach, and conflicting results when comparing the direct anterior and posterior approaches. . Most studies found the mean operating time to be significantly longer when the direct anterior approach was used, with a steep learning curve reported by many. Many authors used validated scores including the Harris hip score, and the Western Ontario and McMaster Universities Arthritis Index. These mean scores were better following the use of the direct anterior approach for the first six weeks post-operatively. Subsequently there was no difference between these scores and those for the posterior approach. Conclusion . There is little evidence for improved kinematics or better long-term outcomes following the use of the direct anterior approach for THA. There is a steep learning curve with similar rates of complications, length of stay and outcomes. . Well-designed, multi-centre, prospective randomised controlled trials are required to provide evidence as to whether the direct anterior approach is better than the lateral or posterior approaches when undertaking THA. Cite this article: Bone JointJ 2017;99-B:732–40

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

Aims. The direct anterior approach (DAA) for total hip arthroplasty (THA) has potential advantages over other approaches and is most commonly performed with the patient in the supine position. We describe a technique for DAA THA with the patient in the lateral decubitus position and report the early clinical and radiological outcomes, the characteristics of the learning curve, and perioperative complications. Methods. All primary DAA THAs performed in the lateral position by a single surgeon over a four-year period from the surgeon’s first case using the technique were identified from a prospectively collected database. Modified Harris Hip Scores (mHHS) were collected to assess clinical outcome, and routine radiological analysis was performed. Retrospective review of the medical records identified perioperative complications, the characteristics of the learning curve, and revisions. Results. A total of 257 patients were included in the study. Their mean age was 60 years (SD 9.0). A total of 164 (64%) were female. The mean mHHS improved significantly from 52.1 (SD 16.2) preoperatively to 94.4 (SD 11) at a follow-up of one year (p < 0.001), with 212 of 225 patients (94%) achieving a minimal clinically important difference (MCID) (> 8 points). Radiological evaluation showed a mean leg length discrepancy of 2.6 mm (SD 5.9) and a mean difference in femoral offset of 0.2 mm (SD 4.9). A total of 234/243 acetabular components (96.3%) were positioned within Lewinnek’s safe zone. Analysis of operating time, blood loss, the position of the components, and complications did not identify a learning curve. A total of 14 patients (5.4%) had a major perioperative complication and three (1.2%) required revision THA. There were no major neurovascular complications and no dislocations. Conclusion. We have described and analyzed a surgical technique for undertaking DAA THA in the familiar lateral decubitus position using a routine operating table, positioning devices, and instrumentation, and shown that it can be performed safely and effectively under these circumstances. Cite this article: Bone Joint J 2021;103-B(7 Supple B):53–58

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

The excitement and enthusiasm that accompanies the introduction of many new technologies and techniques can be self-sustaining, meaning that the appeal of doing something new or different (not necessarily doing something better) becomes the prime driver. Such is likely the case today with the direct anterior approach to total hip arthroplasty. Can THA be done successfully through a direct anterior approach? Certainly the answer is yes; and with experience it can be done in relatively broad groups of patients with an acceptable risk of complications. Is it a better way to do THA than other approaches? Well probably not in 2012. Contemporary THA done with a variety of approaches and coupled with advanced anesthetic, pain management and rapid rehabilitation protocols has been shown to be safe and effective with both short hospital stays (48 hours) and even outpatient surgery in selected patients. No substantial clinical advantage has been shown to date with a direct anterior approach. The sometimes extraordinary claims associated with the direct anterior approach are accompanied by relatively ordinary data. The purported benefits of direct anterior related to more rapid recovery, better function, or a lower dislocation risk just have not proved to be demonstrable in broad groups of patients. In regard to recovery there are now several studies suggesting no difference at 2 hours; 2 days; 2 weeks or 2 years after surgery; and likely no difference at 2 months either. In regard to function there are now multiple gait analysis studies with no demonstrable benefit at 2 weeks or 6 weeks. In regard to lower risk of dislocation if we pool the data from big published studies Sariali (1.5%) Matta (0.6%) Jewett (1%) and Woolson (0%) the mean is 0.88%. Interestingly, contemporary posterior approach THA with formal capsular repair also has <1% dislocation rate when we look at published data from White (0.5%) Pagnano (0.3%) and Dorr (0%). The direct anterior does come at a cost including: longer operative times; additional equipment and/or personnel; unique complications; and in some techniques the need for intra-operative fluoroscopy with attendant exposure to radiation for the surgeon and staff. It is clear in 2012 that the direct anterior approach is just another technique for performing a very successful procedure, namely total hip arthroplasty. With advanced anesthetic, pain management, and rapid rehabilitation protocols it will be extremely difficult to prove any marginal benefit associated with THA surgical technique. To summarize the available data on direct anterior THA it is not unreasonable to conclude that “the extraordinary claims are accompanied by very ordinary data.”

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

A complete cement mantle is important for the longevity of a total hip replacement. In the minimally-invasive direct anterior approach used at the Innsbruck University hospital, the femoral component has to be inserted into the femoral canal by an angulated movement. In a cadaver study, the quality and the extent of the cement mantle surrounding 13 Exeter femoral components implanted straight through a standard anterolateral transgluteal approach were compared with those of 13 similar femoral components implanted in an angulated fashion through a direct anterior approach. A third-generation cementing technique was used. The inner and outer contours of the cement mantles was traced from CT scans and the thickness and cross-sectional area determined. In no case was the cement mantle incomplete. The total mean thickness of the cement mantle was 3.62 mm (95% confidence interval 3.59 to 3.65). The mean thickness in the group using the minimally-invasive approach was 0.16 mm less than that in the anterolateral group. The distribution of the thickness was similar in the two groups. The mean thickness was less on the anteromedial and anterolateral aspect than on the posterior aspect of the femur. There is no evidence that the angulated introduction of Exeter femoral components in the direct anterior approach in cadavers compromises the quality, extent or thickness of the cement mantle

Aims. To establish whether there was a consensus among the members of the Hip Society (HS) on the role of direct anterior approach (DAA) contemporary primary total hip arthroplasty (THA). Methods. An online survey was sent to all 112 active and senior members of the HS, to which 71 members responded. The survey was constructed to determine whether they believed that evidence-based medicine proves, in modern clinical practice, that the DAA has significant benefits compared to risks when contrasted with other approaches. In addition, they were asked if they currently used the DAA. Results. While only 16.9% (12/71) of respondents had been trained in a generic anterior approach during residency, 49.3% (35/71) had used the DAA in their clinical practice in the past or were using it at the present time. Unexpectedly, 42.9% (15/35) of respondents who had used the DAA in the past had abandoned it by the time of this survey. Only 22.5% (16/71) of all respondents believed that evidence-based medicine proves that the DAA has significant benefits compared to risks in contrast to other approaches. Conclusion. A comprehensive literature review found only three prospective randomized clinical trials (RCT) comparing the DAA with another approach with greater than one-year follow-up. Two showed minor benefits within the early postoperative period only, and one of those showed poorer mid-term results. Most of the published comparison studies with short follow-up show longer surgical times and greater blood loss for the DAA, and many three-month comparison studies show higher complication rates for the DAA using a proprietary traction table. The complications included problems with wound healing, lateral femoral cutaneous nerve injury, femoral component loosening, and femoral fractures. Because of the lack of evidence from RCTs showing superiority of the DAA over other approaches and reports of higher complications, the opinion of a large majority (77.5%; 55/71) of HS surgeons was that the DAA lacks sufficient evidence to warrant its use. Cite this article: Bone Joint J 2020;102-B(7 Supple B):57–61

Aims. Use of the direct anterior approach (DAA) for total hip arthroplasty (THA) has increased in recent years due to proposed benefits, including a lower risk of dislocation and improved early functional recovery. This study investigates the dislocation rate in a non-selective, consecutive cohort undergoing THA via the DAA without any exclusion or bias in patient selection based on habitus, deformity, age, sex, or fixation method. Methods. We retrospectively reviewed all patients undergoing THA via the DAA between 2011 and 2017 at our institution. Primary outcome was dislocation at minimum two-year follow-up. Patients were stratified by demographic details and risk factors for dislocation, and an in-depth analysis of dislocations was performed. Results. A total of 2,831 hips in 2,205 patients were included. Mean age was 64.9 years (24 to 96), mean BMI was 29.2 kg/m. 2. (15.1 to 53.8), and 1,595 patients (56.3%) were female. There were 11 dislocations within one year (0.38%) and 13 total dislocations at terminal follow-up (0.46%). Five dislocations required revision. The dislocation rate for surgeons who had completed their learning curve was 0.15% compared to 1.14% in those who had not. The cumulative periprosthetic infection and fracture rates were 0.53% and 0.67%, respectively. Conclusion. In a non-selective, consecutive cohort of patients undergoing THA via the DAA, the risk of dislocation is low, even among patients with risk factors for instability. Our data further suggest that the DAA can be safely used in all hip arthroplasty patients without an increased risk of wound complications, fracture, infection, or revision. The inclusion of seven surgeons increases the generalizability of these results. Cite this article: Bone Joint J 2021;103-B(7 Supple B):38–45

Aims. This study aimed to use intraoperative free electromyography to examine how the placement of a retractor at different positions along the anterior acetabular wall may affect the femoral nerve during total hip arthroplasty (THA) when undertaken using the direct anterior approach (THA-DAA). Methods. Intraoperative free electromyography was performed during primary THA-DAA in 82 patients (94 hips). The highest position of the anterior acetabular wall was defined as the “12 o’clock” position (middle position) when the patient was in supine position. After exposure of the acetabulum, a retractor was sequentially placed at the ten, 11, 12, one, and two o’clock positions (right hip; from superior to inferior positions). Action potentials in the femoral nerve were monitored with each placement, and the incidence of positive reactions (defined as explosive, frequent, or continuous action potentials, indicating that the nerve was being compressed) were recorded as the primary outcome. Secondary outcomes included the incidence of positive reactions caused by removing the femoral head, and by placing a retractor during femoral exposure; and the incidence of femoral nerve palsy, as detected using manual testing of the strength of the quadriceps muscle. Results. Positive reactions were significantly less frequent when the retractor was placed at the ten (15/94; 16.0%), 11 (12/94; 12.8%), or 12 o’clock positions (19/94; 20.2%), than at the one (37/94; 39.4%) or two o’clock positions (39/94; 41.5%) (p < 0.050). Positive reactions also occurred when the femoral head was removed (28/94; 29.8%), and when a retractor was placed around the proximal femur (34/94; 36.2%) or medial femur (27/94; 28.7%) during femoral exposure. After surgery, no patient had reduced strength in the quadriceps muscle. Conclusion. Placing the anterior acetabular retractor at the one or two o’clock positions (right hip; inferior positions) during THA-DAA can increase the rate of electromyographic signal changes in the femoral nerve. Thus, placing a retractor in these positions may increased the risk of the development of a femoral nerve palsy. Cite this article: Bone Joint J 2022;104-B(2):193–199

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

Background. Pre-operative autologous blood donation is recommended as a means of reducing the need for allogeneic transfusion before simultaneous bilateral total hip arthroplasty (THA). However, there have been few reports on the optimal amount of autologous donation for this procedure. In this study we sought to determine the amount of autologous blood required for patient undergoing simultaneous bilateral THA using the direct anterior approach. Methods. We retrospectively enrolled 325 consecutive patients (650 hips) underwent simultaneous bilateral primary THA from January 2012 to June 2014. Thirty-three patients were men and 290 patients were women. The patients’ mean age at THA was 59.1 years. All THAs were performed using the direct anterior approach. Intraoperative blood salvage was applied for all patients and postoperative blood salvage was not applied for any patients. Results. The mean intraoperative blood loss and the mean operative time for the bilateral procedure were 413±165 g and 87.2±12.3 minutes, respectively. Two hundreds and forty-one of the 325 patients (74.2%) donated an average of 1.9 (range, 1–2) units of autologous blood before the operation. The mean hemoglobin levels on the preoperative day, postoperative day 1 and postoperative day 5 were 12.5g/dl, 10.5 g/dl and 9.5 g/dl, respectively. Only 1 patient (0.3%) required postoperative transfusions of allogeneic blood. All of the autologous units collected were transfused, and no units were wasted. Conclusion. Simultaneous bilateral THA can be performed without allogenic blood transfusion in 99.7% of patients. We could not find out significant effectiveness of an average of 1.9 units of autologous blood donation for this procedure in this study. We concluded that simultaneous bilateral THA can be performed without autologous blood donation in healthy patients without severe hip deformity. Whereas, preoperative donation of autologous blood might be suitable for patients with low body weight or patients with severe hip deformity. The minimally invasive aspect of the direct anterior approach seems to allow a low rate of allogeneic blood transfusion in the study

Introduction:. The incidence of heterotrophic ossification after primary total hip arthoplasty (THA) has been reported to be between 8 to 90%. The incidence is higher in lateral approach because of extensive muscular trauma associated with it. There exists limited data on the incidence of heterotrophic ossification after direct anterior approach (DAA) THA. The purpose of this study was to assess the incidence of heterotrophic ossification after THA via the direct anterior approach and the influence of surgical technique and chemoprophylaxis. Method:. A consecutive series of four hundred two primary uncemented direct anterior approach total hip arthoplasties in 378 patients were reviewed for incidence of heterotrophic ossification. In the first 200 total hip arthoplasties an anterior capsulectomy (Group 1) was done for exposure while in the subsequent 202 total hip arthoplasties a capsulotomy (Group 2) followed by complete release of supero-lateral flap of from its attachement to the gluteus minimus muscle and trochanter was performed (Figure 1). Group 1 received warfarin for thromboprophylaxis; while aspirin (thromboprophylaxis) and celecoxib (pain) was used in group 2. Heterotrophic ossification was classified according to Brooker's classification on plain radiographs. Results:. Heterotrophic ossification was significantly less in group 2 (4/202, 1.98%) as compared to group 1 (29/200, 14.5%). No severe heterotrophic ossification was found in group 2. Conclusion:. Release of the superior-lateral capsular flap from the gluteus minimus muscle allows the femoral mobilization required during the femoral preparation and exposes the trochanter for easier retractor placement and thereby minimizes the muscular traumatic insult. When combined with aspirin and celecoxib chemoprophylaxis, this technique may diminish heterotrophic ossification

Aims. Optimal exposure through the direct anterior approach (DAA) for total hip arthroplasty (THA) conducted on a regular operating theatre table is achieved with a standardized capsular releasing sequence in which the anterior capsule can be preserved or resected. We hypothesized that clinical outcomes and implant positioning would not be different in case a capsular sparing (CS) technique would be compared to capsular resection (CR). Methods. In this prospective trial, 219 hips in 190 patients were randomized to either the CS (n = 104) or CR (n = 115) cohort. In the CS cohort, a medial based anterior flap was created and sutured back in place at the end of the procedure. The anterior capsule was resected in the CR cohort. Primary outcome was defined as the difference in patient-reported outcome measures (PROMs) after one year. PROMs (Harris Hip Score (HHS), Hip disability and Osteoarthritis Outcome Score (HOOS), and Short Form 36 Item Health Survey (SF-36)) were collected preoperatively and one year postoperatively. Radiological parameters were analyzed to assess implant positioning and implant ingrowth. Adverse events were monitored. Results. At one year, there was no difference in HSS (p = 0.728), HOOS (Activity Daily Life, p = 0.347; Pain, p = 0.982; Quality of Life, p = 0.653; Sport, p = 0.994; Symptom, p = 0.459), or SF-36 (p = 0.338). Acetabular component inclination (p = 0.276) and anteversion (p = 0.392) as well as femoral component alignment (p = 0.351) were similar in both groups. There were no dislocations, readmissions, or reoperations in either group. The incidence of psoas tendinitis was six cases in the CS cohort (6%) and six cases in the CR cohort (5%) (p = 0.631). Conclusion. No clinical differences were found between resection or preservation of the anterior capsule when performing a primary THA through the DAA on a regular theatre table. In case of limited visibility during the learning curve, it might be advisable to resect a part of the anterior capsule. Cite this article: Bone Joint J 2021;103-B(2):321–328

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

Introduction. Prosthetic replacement remains the treatment of choice for displaced femoral neck fractures in the elderly population, with recent literature demonstrating significant functional benefits of total hip arthroplasty (THA) over hemiarthroplasty. Yet the fracture population also has historically high rates of early postoperative instability when treated with THA. The direct anterior approach (DAA) may offer the potential to decrease the risk of postoperative instability in this high-risk population by maintaining posterior anatomic structures. The addition of intraoperative fluoroscopy can improve precision in component placement and overcome limitations on preoperative planning due to poor preoperative radiographs performed in the emergency setting. Methods. We retrospectively reviewed clinical and radiographic outcomes of 113 consecutive patients with displaced femoral neck fractures treated by two surgeons over a five-year period. All underwent surgery via the DAA using fluoroscopic guidance, and were allowed immediate postoperative weight bearing without any hip precautions or restrictions. Charts were reviewed for relevant complications, while radiographs were reviewed for component positioning, sizing, and leg length discrepancy. Mean follow-up was 8.9 months. Results. Mean age was 79.3 years (range, 42 to 101), 73% of patients were women, and mean BMI was 22.6 kg/m. 2. Ninety patients (80%) received THA while 23 (20%) received unipolar or bipolar hemiarthroplasty. Mean acetabular anteversion was 15.0 degrees (range, 4 to 24) and mean abduction was 39.2 degrees (range, 27 to 51) with 95% of acetabular components in the combined safe zone as described by Lewinnek. Mean radiographic leg-length difference was +2.2 mm (range, −4.9 to +8.8mm). There was no femoral stem subsidence of more than 2mm. Only one patient (0.9%) dislocated postoperatively, who was eventually constrained for recurrent posterior instability 3 months following surgery. Delayed wound healing (6.1%) was the most common postoperative complication. Conclusions. The direct anterior approach allows a safe, effective, and reproducible approach for treatment of displaced femoral neck fractures, with very low rate of early postoperative instability compared to historical controls. The use of intraoperative fluoroscopy allows excellent component positioning, sizing, and restoration of leg length in spite of inconsistent preoperative radiographs

Aims. It has been suggested that the direct anterior approach (DAA) should be used for total hip arthroplasty (THA) instead of the posterior approach (PA) for better early functional outcomes. We conducted a value-based analysis of the functional outcome and associated perioperative costs, to determine which surgical approach gives the better short-term outcomes and lower costs. Methods. This meta-analysis was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol and the Cochrane Handbook. Several online databases were searched. Non-stratified and stratified meta-analyses were conducted to test the confounding biases in the studies which were included. The mean cost and probability were used to determine the added costs of perioperative services. Results. The DAA group had significantly longer operating times (p < 0.001), reduced length of hospital stay by a mean of 13.4 hours (95% confidence interval (CI) 9.12 to 18; p < 0.001), and greater blood loss (p = 0.030). The DAA group had significantly better functional outcome at three (p < 0.001) and six weeks (p = 0.006) postoperatively according to the Harris Hip Score (HHS). However, there was no significant difference between the groups for the HHS at six to eight weeks (p = 0.230), 12 weeks (p = 0.470), six months (p = 0.740), and one year (p = 0.610), the 12-Item Short Form Survey (SF-12) physical score at six weeks (p = 0.580) and one year (p = 0.360), SF-12 mental score at six weeks (p = 0.170) and one year (p = 0.960), and University of California and Los Angeles (UCLA) activity scale at 12 weeks (p = 0.250). The mean non-stratified and stratified difference in costs for the operating theatre time and blood transfusion were $587.57 (95% CI 263.83 to 1,010.29) to $887.04 (95% CI 574.20 to 1,298.88) and $248.38 (95% CI 1,003.40 to 1,539.90) to $1,162.41 (95% CI 645.78 to 7,441.30), respectively, more for the DAA group. However, the mean differences in costs for the time in hospital were $218.23 and $192.05, respectively, less for the DAA group. Conclusion. The use of the DAA, rather than the PA, in THA has earlier benefits for function and pain. However, these are short-lasting, with no significant differences seen at later intervals. In addition the limited benefits were obtained with higher cumulative costs for DAA. Cite this article: Bone Joint J 2021;103-B(6):1078–1087

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

Introduction: Less invasive hip arthroplasty has been promoted since 2002 but with few reports having follow-up data. Existing information is often from developer-surgeons, selecting patients and investigating only the immediate post-operative course. More complete and less biased information is needed. Methods: This prospective series, 275 hips done consecutively beginning April 2003, by a single surgeon using the direct anterior approach first described by Robert Judet, is entirely unselected: 31% obese, 16% over 80, but 22% Charnley category A. Follow-up is at least 2 years. Standardized hip scores and radiographic measurements were obtained regularly. Result: Nine re-operations (3.5%) were required: 2 infections (0.8%), 6 component failures (2%) and 2 superficial wound infections (1%). There were 3 dislocations (1.2%). Charnley Merle d’Aubigne, WOMAC and Harris Hip Scores improved significantly (p=0.001 for each) and component positioning was reproducible. Over 80% of these patients were discharged directly home after an average length of stay 2.2 days. Walking without assistance averaged 4 weeks; return to work 6 weeks. Surgical time and hospital stay decreased significantly during the time of study (p = 0.001 for each). Discussion: Given the excellent result from conventional hip arthroplasty, a change in technique might, at best, slightly benefit most patients at the risk of greatly harming a few. This report suggests that the single incision direct anterior approach is applicable to all THA patients, early recovery is acceptable, and a reasonable learning curve exists; but early complications may be increased when compared to the best experience using traditional approaches

Objectives: The direct anterior approach (DAA) is a distal portion of Smith-Peterson approach to the hip joint. Independent from the length of skin incision, no muscular dissection has to be done for total hip arthroplasty (THA). We have developed minimally invasive THA using DAA on the standard surgical table. The purpose of this study is to present the clinical results of 162 THAs with this approach and to know whether DAA can be safely performed on a standard surgical table. Patients and Methods: Between August in 2004 and June in 2006, 189 primary THAs in 167 patients were performed through DAA in our hospital. We excluded patients with severe developmental dysplasia (12 hips) and with previous hip surgery (7 hips). The severity of dysplasia was graded according to the Crowe classification. We excluded Crowe type 3 or 4 osteoarthritis which requires a modified procedure to cope with the difficult anatomic situation and a different rehabilitation protocol, although it was possible to perform THA with DAA. In order to assess the recovery rate and safety of a rapid rehabilitation protocol after surgery, we also excluded patients with walking disability of uninvolved lower limb (8 hips). Thus, the results included 162 hips in 149 patients (125 women and 24 men). They were followed for at least 3 months postoperatively. The mean age was 62.6 years. The mean BMI was 23.1. The preoperative diagnosis was osteoarthritis in 142 hips, avascular necrosis of the femoral head in 11 hips, femoral neck fracture in 7 hips and rapid destructive cox-arthrosis in 2 hips. In patients with osteoarthritis, 136 hips (95.7%) are secondary to developmental dysplasia (Crowe 1: 112 hips, Crowe 2: 24 hips). Only 5 hips (5.4%) were primary osteoarthritis. The Bicontact total hip stem was used in 135 hips, the CentPilar system in 21 hips and others in 6 hips. Results: Mean surgical time was 70.1 (range: 45 to 150) minutes. Mean operative blood loss was 368 (range: 73 to 1053) ml. Patients were able to walk over 50 meters with T-cane an average of 4.7 (1~30) days after surgery. Complications included one cup migration, one traumatic dislocation, one transient femoral nerve palsy, one heterotopic ossification and one asymptomatic stem subsidence (4 mm) in the early period postoperatively. The cup migration occurred 1 month after surgery and required re-surgery through the same incision. The radiographic analysis showed a mean cup inclination of 42.1 ± 7.1 degrees and a mean anteversion angle of 16.9 ± 4.3 degrees. The femoral component coronal alignment was within 3 degrees of neutral position in 159 hips. Varus alignment of more than 3 degrees was found in 3 hips. Conclusion: We confirmed that the direct anterior approach was a safe and reproducible technique on the standard surgical table and allowed the prosthesis to implant correctly with no muscular dissection and no risk of denervation

The Posterior and Lateral approaches are most commonly used for Total Hip Arthroplasty (THA) in the United Kingdom (UK). Fewer than 5% of UK surgeons routinely use the Direct Anterior Approach (DAA). DAA THA is increasing, particularly among surgeons who have learned the technique during overseas fellowships. Whether DAA offers long-term clinical benefit is unclear. We undertook a retrospective analysis of prospectively collected 10-year, multi-surgeon, multi-centre implant surveillance study data for matched cohorts of patients whose operations were undertaken by either the DAA or posterior approach. All operations were undertaken using uncemented femoral and acetabular components. The implants were different for the two surgical approaches. We report the pre-operative, and post operative six-month, two-year, five-year and 10-year Oxford Hip Score (OHS) and 10-year revision rates. 125 patients underwent DAA THA; these patients were matched against those undergoing the posterior approach through propensity score matching for age, gender and body mass index. The 10-year revision rate for DAA THA was 3.2% (4/125) and 2.4% (3/125) for posterior THA. The difference in revision rate was not statistically significant. Both DAA and Posterior THA pre-operative OHS were comparable at 19.85 and 19.12 respectively. At the six-month time point, there was an OHS improvement of 20.89 points for DAA and 18.82 points for Posterior THA and this was statistically significant (P-Value <0.001). At the two, five and 10-year time-points the OHS and OHS improvement from the pre-operative review were comparable. At the 10-year time point post-op the OHS for DAA THA was 42.63, 42.10 for posterior THA and the mean improvement from pre-op to 10-years post op was 22.78 and 22.98 respectively. There was no statistical difference when comparing the OHS or the OHS mean improvements at the two, five and 10-year point. Whilst there was greater improvement and statistical significance during the initial six month time period, as time went on there was no statistically significant difference between the outcome measures or revision rates for the two approaches

Introduction. The direct anterior approach (DAA) total hip arthroplasty (THA) is now widely used. A recent unpublished survey of 1000 AAHKS members found that over half currently used a DAA technique and that most users felt the DAA was financially beneficial to their practice. Conversely, non-DAA users felt that their surgical volume had decreased. An online survey of Hip Society (HS) members was done to determine member's preference for a surgical approach and opinions regarding the DAA. Methods. 71 of 112 active and senior HS members (63%) responded to this 20-question survey. Results. The survey found that only 17% of respondents had trained in an anterior approach during residency, but that half (35 respondents) had used this approach in practice at one time. Subsequently, 43% of those 35 DAA users had abandoned it. The DAA learning curve was estimated at over 50 cases by 47% of respondents. Only 23% of 71 respondents answered “yes” to the statement “Do you believe that evidence-based medicine proves significant benefits over risks of the DAA THA versus other approaches?” Financial factors were common reasons for beginning to use the technique including accommodating patient requests and preventing the loss of patients to other DAA surgeons. Conclusion. 15 years after the emergence of “minimally invasive” DAA THA, a literature review finds that only one small (44 patient) clinical trial with >1-year follow-up showed small early functional benefits but with longer average surgical times and higher blood loss. If the DAA procedure has minimal benefits, is more difficult to perform with a high complication rate (LFCN injury, femoral fracture and loosening) in the hands of non-specialists and has a long learning curve (that caused a significant percentage of HS DAA users to abandon it), then financial factors must be the main reasons for its popularity. For any tables or figures, please contact the authors directly

In recent years, the direct anterior approach (DAA) has become a standard approach for primary total hip arthroplasty (THA). With the increasing use of the DAA in primary cases also more and more revision surgeries are performed through the same interval. With ability to extend the DAA interval proximally and distally, loose cups, loose stems, and even periprosthetic femoral fractures (PPF) can be treated. Especially, PPF are devastating complications causing functional limitations and increased mortality. Therefore, we conducted a study to report the outcome of surgical treatment of PPF with the DAA interval. We report on the one year complications and mortality in 40 cases with a mean clinical follow-up of 1.5 years. Mean age of patients was 74.3 years. Fractures were classified as Vancouver B2 (36), and B3 (N=4). In 14 cases, a standard stem was used, and in 26 cases a modular revision stem. In 30 cases, a distal extension +/- tensor release was used, in 4 cases a proximal tensor release was done, and in the remaining 6 cases revision could be performed without extension of the approach. Median cut/suture time was 152 minutes (IQR 80 – 279). The overall complication rate in our patient group was 12.5%. 2 patients died in the first three months after operation. One patient had a transient femoral nerve palsy, which completely recovered. The DAA interval to the hip for the treatment of PFF showed similar results compared with other approaches regarding mortality, complications, fracture healing, dislocation rate and clinical results. We conclude that femoral revision in case of PPF in the DAA interval is a safe and reliable procedure. Each Vancouver type of periprosthetic fracture can be treated by use of this approach

Introduction. The incorporation of computer navigation in total hip arthroplasty (THA) has been much slower then for total knee arthroplasty (TKA). Computer navigation has proven itself in the realm of TKA but still has yet to advance in THA. The reasons for this include the lack of ease of incorporation, accuracy and precision, and the addition of overall operative time. Another reason for this lack of progress is that a majority of THA's are done with the patient in the lateral position through a posterior or lateral approach making the tracker placement and the registration process somewhat cumbersome. In the direct anterior approach the patient is in the supine position, which accommodates pelvic tracker placement and significantly facilitates the registration process. At our institution we use the direct anterior approach and computer navigation on all of our primary THA's. We hypothesized that computer navigation facilitates cup placement and leg length determination with out significantly increasing our operative time. Materials and Methods. This was a prospective study comparing a consecutive series of 150 computer navigated total hips to a consecutive series of 150 none navigated total hips. The two groups were similar by age, sex, and BMI. Operative times were collected using our secure online database. The start and stop of operative time was incision to final reduction respectively. Post operative radiographs were analyzed using TraumaCad 2.0 (Voyant Health, Columbia, MD). Cup angle and leg length were measured on A/P pelvic views. Simple descriptive statistics and t-tests were used to analyze data. Results. There were a total of 134 men and 166 women with a pre operative diagnosis of osteoarthritis. The conventional cohort contained 64 men and 86 women with an average age of 65.6 (26.1-91.3) and BMI of 29.3(15.7-50.9). The computer navigation cohort contained 70 men and 80 women with an average age of 65.5 (44.8-90.2) and BMI of 28.6 (17.5-44.0). The average operative times of the conventional and computer navigation cohorts were 62.4 min (33-165) and 53.0 min (38-63) (p<0.0001) respectively. The average cup angle was 37.2 (25-52) for the conventional cohort and 41.0 (26-55) for the computer navigation cohort (p=0.0046). The leg length discrepancy average was 3.2 mm (-13.0mm to 13.0mm) for the conventional cohort and 2.1 mm (-6.0mm to 15.0mm) for the computer navigation cohort (p=0.0012). Conclusion. The results from our study suggest that computer navigation is easy to incorporate when utilizing a direct anterior approach and in fact shortens the operative time. The accuracy and precision of cup angle placement and leg length discrepancy are comparable to our conventional method but appears to be slightly improved with computer navigation. Although more work is needed to progress this promising technology, we feel that incorporating computer navigation for hip surgery in the supine position is simple and of great value

Acetabular component positioning is commonly referenced with the pelvis in the supine position in direct anterior approach THA. Changes in pelvic tilt (PT) from the pre-operative supine to the post-operative standing positions have not been well investigated and may have relevance to optimal acetabular component targeting for reduced risk of impingement and instability. The aims of this study were therefore to determine the change in PT that occurs from pre-operative supine to post-operative standing, and whether any factors are associated with significant changes in tilt ≥13° in posterior direction. 13° in a posterior direction was chosen as that amount of posterior rotation creates an increase in functional anteversion of the acetabular component of 10°. 1097 THA patients with pre-operative supine CT and standing lateral radiographic imaging and 1 year post-operative standing lateral radiographs (interquartile range 12–13 months) were reviewed. Pre-operative supine PT was measured from CT as the angle between the anterior pelvic plane (APP) and the horizontal plane of the CT device. Standing PT was measured on standing lateral x-rays as the angle between the APP and the vertical line. Patients with ≥13° change from supine pre-op to standing post-op (corresponding to a 10° change in cup anteversion) were grouped and compared to those with a <13° change using unpaired student's t-tests. Mean pre-operative supine PT (3.8±6.0°) was significantly different from mean post-operative standing PT (−3.5±7.1°, p<0.001), ie mean change of −7.3±4.6°. 10.4% (114/1097) of patients had posterior PT changes ≥13° supine pre-op to standing post-op. A significant number of patients, ie 1 in 10, undergo a clinically significant change in PT and functional anteversion from supine pre-op to standing post-op. Surgeons should be aware of these changes when planning component placement in THA

The purpose of this study was to investigate the influence of surgical approach on femoral stem version in THA. This was a retrospective database review of 830 THAs in 830 patients that had both preoperative and postoperative CT scans. All patients underwent staged bilateral THAs and received CT-based 3D planning on both sides. Stem version was measured in the second CT-scan and compared to the native neck axis measured in the first CT-scan, using the posterior condyles as the reference for both. Cases were performed by 104 surgeons using either a direct anterior (DAA, n=303) or posterior (PA, n=527) approach and one of four stem designs: quadrangular taper, calcar-guided short stem, flat taper and fit-and-fill. Sub-analyses investigated changes in version for low (≤5°), neutral (5–25°) and high (≥25°) native version subgroups and for the different implant types. Native version was not different between approaches (DAA = 12.6°, PA = 13.6°, p = 0.16). Overall, DAA stems were more anteverted relative to the native neck axis vs PA stems (5.9° vs 1.4°, p<0.001). This trend persisted in hips with high native version (3.2° vs -5.3°, p<0.01) and neutral native version (5.3° vs 1.3°, p<0.001), but did not reach significance in the low native version subgroup (8.9° vs 5.9°, p=0.13). Quadrangular taper, calcar-guided, and flat taper stem types had significantly more anteversion than native for DAA, while no differences were found for PA. Stems implanted with a direct anterior approach had more anteversion than those implanted with a posterior approach. The smaller surgical field, soft tissue tension and lack of a “tibial” vertical reference frame may contribute to this finding

INTRODUCTION. The capsular releasing sequence is crucial to safely conduct the Direct Anterior Approach for THA on a regular OR table. The release of the anterior capsule is the first step of the releasing sequence and allows for optimal exposure. This can be done by either resecting a part of the anterior capsule or by preserving it. Our zero hypothesis was that clinical outcomes would not be different between both techniques. MATERIALS & METHODS. 190 Patients operated between November 2017 and May 2018, met the inclusion criteria and were randomly allocated in a double blinded study to either the capsular resection (CR)(N=99) or capsular preservation (CP)(N=91) cohort. The same cementless implant was used in all cases. Patient-reported outcome measures (PROMS) were collected pre- and post-operatively at 6 weeks, 3 months and 1 year. Adverse events were recorded. Outcomes were compared with the Mann-Withney U test and a significance level of p<0,05. RESULTS. Both cohorts had significant improvements of all PROMS post-operatively. There was no significant difference in HSS, HOOS or SF-36 between both cohorts (p>0,05). The incidence of peri-articular muscle soreness and transient tenderness in the groin was 7.5% of patients in the CR cohort and in 9.3% in the CP cohort, at 6 weeks to 3 months post-operatively (p>0.05). At one year, 80% of patients had a forgotten hip (p>0.05). There were no dislocations, readmissions or reoperations in both groups. Acetabular and femoral component position was similar in both groups (p>0,05). CONCLUSION. No clinical differences were found between resection or preservation of the anterior capsule when performing a primary THA through the anterior approach on a regular OR table. During the learning curve, it might be advisable to resect a part of the capsule in order to optimize the acetabular exposure, without compromising the clinical outcomes

Background. The use of the direct anterior approach (DAA) for total hip arthroplasty (THA) has increased in recent years. This is in part due to the proposed benefits of a faster early recovery and a lower risk of dislocation. The purpose of this study is to understand the dislocation rate in a non-selective, consecutive cohort of patients undergoing THA via the DAA including those at high risk for instability due to spinopelvic pathology. Methods. We performed a retrospective review of a large prospectively collected single institution database assessing all patients undergoing THA via the DAA between 2011 and 2017. The primary outcome measure was dislocation at minimum two-year follow-up. We then stratified patients by known risk factors for dislocation including spinopelvic pathology and performed an in-depth analysis of those patients who had a dislocation event. Results. 2,831 hips in 2205 patients were included in the study. Mean age was 64.9 (24–96) and 1,595 (56.3%) were female. Mean BMI was 29.2 (15.1–53.8). There were 11 dislocations within one year of the index operation (0.38%) and 13 total dislocations at terminal follow-up (0.45%). Five dislocations required revision (38.4% of dislocations 0.17% overall). When stratified by experience the dislocation rate for surgeons who had completed their learning curve was 0.15% compared to 1.11% in those who hadn't. There were 666 patients with an established diagnosis of spinopelvic pathology or prior surgical instrumentation, only 2 (0.30%) dislocated and neither required revision. Conclusion. In a non-selective, consecutive cohort of patients undergoing THA via the DAA the risk of dislocation is low. Even amongst patients with lumbosacral stiffness secondary to spinal instrumentation or degenerative changes, the rate of dislocation is low following THA via the DAA. Our data suggests that utilizing the DAA in high risk patients may be protective against dislocation without the need for additional constraint or the use of newer bearing constructs that lack long term outcome studies. The inclusion of seven surgeons suggests that these results are generalizable

Aims. The hypothesis of this study was that thigh circumference, distinct from body mass index (BMI), may be associated with the positioning of components when undertaking total hip arthroplasty (THA) using the direct anterior approach (DAA), and that an increased circumference might increase the technical difficulty. Patients and Methods. We performed a retrospective review of prospectively collected data involving 155 consecutive THAs among 148 patients undertaken using the DAA at an academic medical centre by a single fellowship-trained surgeon. Preoperatively, thigh circumference was measured at 10 cm, 20 cm, and 30 cm distal to the anterior superior iliac spine, in quartiles. Two blinded reviewers assessed the inclination and anteversion of the acetabular component, radiological leg-length discrepancy, and femoral offset. The radiological outcomes were considered as continuous and binary outcome variables based on Lewinnek’s ‘safe zone’. Results. Similar trends were seen in all three thigh circumference groups. In multivariable analyses, patients in the largest 20 cm thigh circumference quartile (59 cm to 78 cm) had inclination angles that were a mean of 5.96° larger (95% confidence interval (CI) 2.99° to 8.93°; p < 0.001) and anteversion angles that were a mean of 2.92° larger (95% CI 0.47° to 5.37°; p = 0.020) than the smallest quartile. No significant differences were noted in leg-length discrepancy or offset. Conclusion. There was an associated increase in inclination and anteversion as thigh circumference increased, with no change in the risk of malpositioning the components. THA can be performed using the DAA in patients with large thigh circumference without the risk of malpositioning the acetabular component. Cite this article: Bone Joint J 2019;101-B:529–535

Background. Despite growing interest in direct anterior approach total hip arthroplasty, perioperative femoral fracture and early aseptic loosening are increasingly recognized complications. Previous research has documented the role of surgeon experience in association with these femoral complications. The purpose of this study was to explore the relationship between femoral component design and early periprosthetic femoral complications. Methods. This was an extension of previous work with an updated patient cohort of 5090 consecutive direct anterior primary total hip arthroplasties at a single institution with a single-taper, wedge femoral stem with 4 variants involving length and geometry: Group 1) full length, standard profile; Group 2) full length, reduced distal profile; Group 3) short length, standard profile; and Group 4) short length, reduced distal profile. Records were reviewed retrospectively for the incidence of early periprosthetic fracture or aseptic loosening and analyzed with regard to patient demographics and femoral stem type. Results. There were 42 (0.83%) periprosthetic femur complications observed in the early postoperative period. Increased age (p<0.001) and female gender (p=0.023) were significantly associated with incidence of femoral complications in univariate analysis, while age maintained this significant relationship in multivariate analysis (P<0.001). There was a trend toward increased complication rate in patients receiving a short stem with full profile taper (1.27%, p=0.0539). Conclusion. Despite an overall low rate of femoral complications after direct anterior total hip arthroplasty, the risk is increased in elderly patients and females. Furthermore, femoral stem design may portend an elevated risk of these complications

Aims. Accurate placement of acetabular and femoral stem components in total hip arthroplasty (THA) is an important factor in the success of the procedure. A variety of free hand or navigated techniques is reported. Survivorship and complications have been shown to be directly related to implant position during THA. The aim of this cadaver study was to assess the accuracy of the placement of the components in THA using patient specific instruments (PSI) in combination with a 3D planning software and the direct anterior approach. Method. Patient specific instruments (PSI) were developed to guide the surgeon during THA that were 3D printed with their bone models following a 3D software planning protocol (LPH software V2.5.1, Onefit-Medical, Eos Imaging Company, Besancon, France). Acetabular guides: cup, offset and straight reamer handle and impactor, femoral- and chisel guides were used in each THA (Fig. 1). To define anatomic bone landmarks and to generate a 3D model of each hip joint CT scans were performed preoperatively. The planning of component position was done by one surgeon (AZ) preop. Surgery was performed by two experienced surgeons (AZ, SD) on cadaver specimen with 4 hips in two separate series. A total of 8 hip replacements were evaluated pre- and postoperatively using CT-scans of each hip joint to compare planned to achieved results. Mechanical simulations of the guides were carried out to verify that there were no conflicts between the different instruments. To meet the ISO standard 16061: 2015 the compatibility of the instruments with the guides has been checked. Parameters were evaluated in 3D pelvic and femoral planes: center cup position, inclination angle, anteversion angle, cutting height and plan orientation, anteversion angle, flexion/extension angle, varus/valgus angle, anatomical and functional leg length, offset. Acceptance criteria: postop. parameters evaluated must not have a deviation of more than 5 degrees, 2,5 mm according to preop. planning. For every THA the test protocol has been completely realized. Results. The difference between the preop. and postop. measures in the first series of 4 hips revealed 2 outliers because of fractures of the acetabulum in 2 cases, related to bad cadaver quality. In the second series we found satisfactory results comparing the planned preop and postop component position (Fig. 2). For example difference of leg length showed a mean absolute of 1,58 mm, standard deviation 1,21 mm (min 0,62; max 3,34 mm). Offset revealed a mean absolute of 1,62 mm, standard deviation 0,57 mm (min 1,06; max 2,14 mm) concerning the difference between preop. planning and result postop. Conclusion. Accurate and safe placement of total hip components in THA, both acetabular cup and stem, performing the direct anterior approach can be achieved using a 3D preoperative planning along with patient specific instruments. The results of the cadaver study tests are promising and that is to be proven in the clinical setting and by application in the future

Introduction: Minimally invasive total hip arthroplasty has evoked substantial controversy with regard to whether it provides superior outcomes compared with conventional total hip arthroplasty. The objective of this study was to compare the results of a minimal invasive direct anterior approach (MIDA) with those of a conventional lateral transgluteal approach (CLT). Methods: 120 patients (120 hips) admitted for unilateral total hip arthroplasty were randomized to undergo surgery via minimal invasive direct anterior or conventional lateral transgluteal approach. Patients with a body mass index of more than 35, previous hip surgery, preoperative neurological deficits and with an age of more than 80 years were excluded. Two surgeons performed all procedures. To estimate muscle damage serum creatinkinase was assessed. Blood loss was calculated according to Rosencher by comparing preoperative to postoperative hematocrit. Postoperative pain and the ability to perform the activities of daily living were recorded in a dairy via modified WOMAC first on a daily basis, then on each second day and finally once a week for a total of 12 weeks. WOMAC questionnaire and SF-36 were administered at 6 weeks and 3 months follow-up. Results: The groups were similar demographically. Patients in MIDA group had significantly less total blood loss (p = 0.006), postoperative blood levels of creatinine kinase were significantly lower (p = 0.001). Operative time was similar in both groups, we found no difference in component placement. Physical component summary of SF-36 at 12 weeks follow-up showed a significant benefit for the MIDA group. Averaged modified WOMAC scores and their pain and function subscores demonstrated a clear advantage on every recorded day during the first 12 weeks for MIDA. Median WOMAC sum score and respective pain as well as function subscores were better in the MIDA group at 6 and 12 weeks follow up. Conclusions: A minimally invasive direct anterior approach is superior to a conventional lateral transgluteal approach with regard to blood loss and muscle trauma, resulting in better health related quality of life in the first three months after operation

Increasing data is emerging, consistently demonstrating a more rapid recovery for patients undergoing direct anterior approach (DAA) surgery. In one study, objective findings of early recovery including timed up and go tests, Functional Independence Measures are significantly faster in the first 2 weeks, and normalise by 6 weeks. A more recent randomised study shows a quicker achievement of the functional milestones of discontinuing walking aids, discontinuing opioids, stair ascent, and walking 6 blocks, as well as accelerometer measures of activity in the first 2 weeks after surgery. In both of these studies, seasoned surgeons well beyond their learning curves performed the surgeries. A prospective MRI study of volume before and after surgery has shown full recovery or mild hypertrophy of most muscles at an average of 24 weeks from surgery, but a sustained loss of muscle volume for the obturator internus muscle in the DAA, and sustained loss of muscle volume for obturator internus, obturator externus, piriformis, and quadratus femoris in the posterior approach patients. The muscles that are released in the surgeries recover incompletely. Prospective assessment of muscle strength demonstrated loss of flexion strength in the DAA group and loss of external rotation strength in the posterior group at 6 weeks. By 3 months, the DAA group had returned to normal in their strength, while the posterior group had persistent external rotation weakness. Prospective assessment of gait, pre-operatively and at 6 months showed similar improvements in frontal and sagittal plane range of movement in gait, with a similar improvement in transverse plane movement (internal and external rotation) in the DAA group, but no change in the posterior cohort. The precision of socket placement, after undergoing a learning curve, was greater with the use of fluoroscopy in the DAA. Cutting and subsequently repairing a muscle can have a clinically insignificant, but nonetheless objectively measurable effect on the function of that muscle. Observed downsides of DAA include a higher prevalence of wound complications in obese patients, and possibly a higher risk of periprosthetic fractures in elderly, thin women. Recent larger registry data would also suggest that there is no difference in dislocation rate between the 2 referenced approaches, and possibly a higher femoral revision rate for the DAA. These may be honest and real depictions of a large learning curve as we further understand and disseminate the subtleties of proper execution of DAA surgery

Introduction. Dislocation is one of severe complications after total hip arthroplasty (THA). Direct anterior approach (DAA) is useful for muscle preservation. Therefore, it might be also effective to reduce dislocation. The purpose of this study is to investigate the ratio and factors of dislocations after THA with DAA. Materials & methods. Nine hundred fifity two primary THAs with DAA are examined. Mean age at operation was 64.9 yrs. 838 joints are in women and 114 (joints) in men. All THAs were performed under general anesthesia in supine position. We reviewed the ratio, onset and frequency of dislocations, build of the patients, preoperative Japanese Orthopaedic Association (JOA) Hip scores, implant setting angles, pelvic tilt angles and diameter of inner heads. Results. The ratio of dislocation was 14 joints (1.47%). All patients were women and mean age was 67.1 yrs. Anterior dislocation was in 9 joints and posterior was in 5 joints. Primary diagnosis for THA was the following: osteoarthritis in 9 hips and rheumatoid arthritis in 5 (hips). About primary onset, 7 joints were within 3 weeks, 5 joints from 3 weeks to 3 months and 2 joints after 3 months. About frequency, 9 joins were simple and 5 joints were multiple. Revision surgery was done in 2 joints due to ceramic fracture and cup migration. About build of the patients, mean body height was 153.1cm, mean body weight (was) 55.6 kg and mean BMI (was) 23.6. Mean preoperative JOA score was 40.0 points. Implant setting angles were the following: mean cup inclination was 42.4 degree, mean cup anteversion (was) 24.8 degree and mean stem anteversion (was) 18.7 degree. Cup inclination and anteversion in the anterior dislocation group were bigger than that in no dislocation group. Stem anteversion in the posterior dislocation group was smaller than that in no dislocation group. The difference of pelvic tilt angle between supine and standing position was 6.4 degree. It was significant bigger in the posterior dislocation group. The most of used Inner head was 28mm in 375 joints. There was no significant difference of the dislocation rate among inner head size. Discussion and conclusion. DAA-THA can expect the reduction of dislocation rate due to intermusclar approach; however there are some reports of high dislocation rate because of difficult technique. In our study, dislocation ratio was 1.47%. Risk factors of dislocation after THA was rheumatoid arthritis, large cup inclination and anteversion for anterior dislocation, small stem anteversion and large difference of pelvic tilt angle between supine and standing position for posterior dislocation

Evidence supporting the use of virtual reality (VR) training in orthopaedic procedures is rapidly growing. However, the impact of the timing of delivery of this training is yet to be tested. We aimed to investigate whether spaced VR training is more effective than massed VR training. 24 medical students with no hip arthroplasty experience were randomised to learning the direct anterior approach total hip arthroplasty using the same VR simulation, training either once-weekly or once-daily for four sessions. Participants underwent a baseline physical world assessment on a saw bone pelvis. The VR program recorded procedural errors, time, assistive prompts required and hand path length across four sessions. The VR and physical world assessments were repeated at one-week, one-month, and 3 months after the last training session. Baseline characteristics between the groups were comparable (p > 0.05). The daily group demonstrated faster skills acquisition, reducing the median ± IQR number of procedural errors from 68 ± 67.05 (session one) to 7 ± 9.75 (session four), compared to the weekly group's improvement from 63 ± 27 (session one) to 13 ± 15.75 (session four), p < 0.001. The weekly group error count plateaued remaining at 14 ± 6.75 at one-week, 16.50 ± 16.25 at one-month and 26.45 ± 22 at 3-months, p < 0.05. However, the daily group showed poorer retention with error counts rising to 16 ± 12.25 at one-week, 17.50 ± 23 at one-month and 41.45 ± 26 at 3-months, p<0.01. A similar effect was noted for the number of assistive prompts required, procedural time and hand path length. In the real-world assessment, both groups significantly improved their acetabular component positioning accuracy, and these improvements were equally maintained (p<0.01). Daily VR training facilitates faster skills acquisition; however weekly practice has superior skills retention

We investigated whether a novel, real-time fluoroscopy based navigation system optimized component positioning and leg length in fluoroscopically aided Direct Anterior Approach Total Hip Arthroplasty (DAA-THA). We retrospectively reviewed 75 fluoroscopically assisted DAA-THA performed by a single surgeon: 37 procedures used the software intraoperatively to overlay anteversion, inclination, and leg length information over the existing fluoroscopic radiograph with the aim of enhancing component positioning. The control group consisted of 38 procedures from the single surgeon's patient pool who had undergone non-navigated fluoroscopic assisted DAA-THA one month prior to the system's trial. We used the software to compute each data point on an immediate post operative AP radiograph to replicate the intra operative measurement process. Our results demonstrate that the navigation group measurements were significantly closer to the target numbers with less variation. The mean values were significantly closer to target values anteversion (control: 14°, navigated: 19.1°), inclination (control: 37.7°, navigated: 40.8°) and leg length discrepancy (control: 4.7mm, navigated: 0.1mm). The mean difference from target value were also statistically significant: for anteversion (control: −6.0°, navigated: −0.9°), inclination (control: −2.3°, navigated: 0.8°) and leg length discrepancy (control: 2.7°, navigated: −1.9°). In addition, surgical time was shorter in the navigation group (75.7 vs. 74 minutes; p=0.001). The p values were all statistically significant (anteversion 0.0001, inclination 0.0019, LLD < 0.001 and surgical time 0.001). The real-time feedback and calculations provided by the navigation software provided a reproducible precision for component positioning and leg length measurement during DAA-THA. For any figures or tables, please contact authors directly

Direct anterior approach (DAA) is one of the best way to the hip joint for prevention of post-operative dislocation. We have applied this method as minimum invasive surgery (MIS) to more than two hundred developmental dysplastic hip of Japanese patients in total hip arthroplasty (THA) and there is no post-operative dislocation within three years of last observation carried forward (LOCF). The reason of this benefit is derived from the accuracy of cup positioning and keeping good muscle balance. But the learning curve is very important and some technical pitfalls are there in this approach. We have chosen thirty four patients that the duration of operating time more than one and half hours and loss of blood more than five hundred gram in hour series. The most important factors of the difficulties are the combinations of shortening of femoral neck, especially Perthes like deformity of developmental deformities of the hip joint (DDH) and widening of pelvic bone for the reason of insufficiency working spaces and the difficulties of broaching insertion (8/34). The second factor is the contracture of hip and knee joints combinations for the difficulties of lift up the proximal femur as broaching stem (3/34). The obesity, Body Mass Index (BMI) above thirty is not the reason of difficulties of women in our series. DAA can be extended to Smith-Petersen approach and very useful technique for primary THA in Japanese dysplastic hip patients

Background. Minimally invasive surgery is being widely used in the field of total hip arthroplasty (THA). The advantages of the direct anterior approach (DAA), which is used in minimally invasive surgery, include low dislocation rate, quick recovery with less pain, and accuracy of prosthesis placement. However, minimally invasive surgery can result in more complications related to the learning curve. The aim of this study was to evaluate the learning curve of DAA-THA performed by a senior resident. Methods. Thirty-three consecutive patients (33 hips) who underwent primary THA were enrolled in this study. All operations were performed by a senior resident using DAA in the supine position without the traction table. The surgeon started using DAA exclusively for all cases of primary THA after being trained in this approach for 6 months. Operative time, intraoperative blood loss, complications, and accuracy of prosthesis placement were investigated. Results. The mean intraoperative blood loss was 524 mL (range, 130–1650 m L). The mean operative time was 60 min (range, 41–80 min). Radiographic analysis showed an average acetabular anteversion angle of 17.0±3.3°, abduction angle of 37.8±4.3°, and stem alignment of 0±0.8°. Thirty-two (97%) of 33 cups were placed within the Lewinnek's safe zone. The overall complication rate was 12% (4 of 33 hips), including 1 proximal femoral fracture (salvaged with circumferential wiring), 1 temporary femoral nerve palsy (completely recovered in 2 weeks), 1 stem subsidence (5 mm), and 1 cup migration. Three of these complications were occurred in the first 10 cases. No revision surgery was required, No postoperative dislocation occurred. Conclusion. We investigated the learning curve of DAA-THA performed by a senior resident. We considered the first 10 cases as the learning curve, but concluded that with adequate training this procedure can be performed safely and effectively without increasing the risk of complications

Background. Acromegaly, which stems from high level of serum growth hormone secreted by a benign tumour in the anterior pituitary gland, is likely to cause severe peripheral joint pains due to hypertrophic changes in such joints. Recently, the life expectancy of such patients has been improved and more patients with acromegaly have undergone joint surgeries to mitigate joint pain and malfunctions. However, little is known about to what extent surgical procedures can improve the joint functions of acromegalic patients compared to non-acromegalic cases. Methods. First, we qualitatively analysed prognosis of total hip arthroplasty (THA) of acromegalic patients by investigating 11 cases in which direct anterior approach (DAA) THAs were performed to 8 acromegalic patients in our hospital between 2012 and 2015. Second, we quantitatively compared the functional prognosis of the 11 cases with that of 107 non-acromegalic cases. Technically, to control the difference in age, sex, height, and weight between the two patient groups, we first identified a model that could predict 3month-/6month-/12month-functional prognosis in the control cases. We estimated differences in functional outcomes between the two groups by calculating how accurately the control-case-based model could predict the prognosis of the acromegalic cases. Results. In the qualitative analysis, we found that compared to the control, the most acromegalic cases had atypically advanced degenerative arthritides with osteophytes and enthesophytes proliferations. In addition, some cases showed other signs, such as flattering of femoral head and arthritis with slight osteophytes. Regarding surgical procedures, acromegalic cases were likely to require longer operation time and larger amounts of blood loss compared to the control. In the quantitative analysis, we first identified a model in which age and body height could predict the functional prognosis of DAA THA in the non-acromegalic cases (F[2,104] = 6.7, P = 0.0017). We then found that the actual functional outcomes of the acromegalic cases were not significantly different from those predicted by this control-case-based model (P = 0.18). Conclusions. The qualitative analysis shows the atypical joint structures and resultant prolonged operation time and blood loss in the acromegalic cases. However, the quantitative analysis could not find significant differences in prognosis between the acromegalic and non-acromegalic cases. Although these observations and analyses need to be examined in studies with large sample sizes, this work suggests that functional outcomes of DAA THA to acromegalic patients can be comparable to that to non-acromegalic patients

Direct anterior approach (DAA) using the Hueter interval for total hip replacement (THA) provides an inter-nervous and inter-muscular access to the hip joint. Although it is technically demanding, the learning curve has been shown to be around 40 cases and 6 months in a high-volume joint surgeon's practice. A level-one study has demonstrated that DAA provides equal or better results and an equivalent rate of complications when compared to the highly utilized direct lateral approach. Using the available evidence to perform a multi-criteria decision analysis we demonstrated that DAA can be the most efficient approach to perform THA. From our standpoint, there is no reason to speculate a surgical approach with such advantages will be abandoned in the future. The DAA is here to stay, and may become the gold standard for THA

Introduction. Early functional recovery following total hip arthroplasty (THA) has the potential to increase patient satisfaction and reduce resource utilization. The direct anterior approach (DA) has been shown to provide earlier recovery compared to the direct lateral (DL) approach based on functional tests and outcome scores. There are limited studies that objectively evaluate functional recovery comparing the two approaches in the early post-operative period. Activity trackers have emerged as a valid tool to objectively quantify physical activity levels and potentially better assess functional status compared to commonly reported functional questionnaires. The purpose of this study is to measure physical activity levels in patients undergoing THA with the DA approach and compare these to THA with the direct lateral approach in the immediate postoperative period. Methods. In a tertiary academic center we prospectively enrolled patients with primary OA that were eligible for a primary THA undergoing either the DA or the DL approach using the same prosthesis. Patients with comorbidities precluding them from ambulation, diagnoses of AVN or RA or undergoing bilateral THA were excluded. The number of steps walked per day were measured using wristband activity tracking technology for one week preoperatively, the first 2 weeks postoperatively and for 1 week leading up to their 6-week follow-up appointment. The University of California, Los Angeles (UCLA) activity score was also collected at the same two time points. Demographics were analyzed with descriptive statistics. A non-parametric Mann Whitney U test was used to determine whether a difference in physical activity levels exist between the DA and DL approach groups in the first 2 weeks and 6 weeks postoperatively. Results. One hundred and thirty-nine patients with primary OA were enrolled. Seventeen were withdrawn prior to beginning the study (7 – patient requested, 5 – could not work the activity tracker, 5 – health issues). Following enrolment 29 patients were withdrawn due to lack of data available for analysis. There were 53 patients in the DA group and 40 patients in the DL group. Patient demographics including age and gender were similar in both groups. Body mass index was higher in the DL group (32.4 ± 6.9) compared to the DA group (28.2 ± 3.9) (p=0.001). There was no difference in the average steps taken per day or the UCLA score between the two groups preoperatively. The UCLA score and the overall average steps walked collected at 2 weeks postoperatively were significantly higher in the DA group compared to the DL group (median 4(1–6) vs. 3(2–6), p<0.001 and median 1641(329 – 8678) vs. 890(87 – 4347), p<0.001) respectively. When each postoperative day was evaluated individually, the DA group had a greater number of steps per day for the entire two weeks. At 6 weeks, the average number of steps taken by the DA group (median 4734 (1703 – 16605) () were greater than those taken by the DL group (median 3534 (462–8665) ± 2263) (p=0.007). A similar finding was demonstrated for the UCLA with the DA having greater self-reported activity levels (median 6 vs. 4, p<0.001). Discussion/Conclusions. The DA approach provided faster functional recovery in the immediate postoperative period compared to the DL approach as measured by a wristband activity tracker. DA approach patients walked a greater number of steps at both 2 weeks and 6 weeks. Further examination regarding the economic implications of the improved early function from the perspective of the patient, caregiver, and care payer is indicated

Dual mobility cups (DMC) reduce the risk of dislocation in femoral neck fractures (FNF). Direct anterior approach (DAA), historically promoted for better stability, has been developed in recent years for better functional results. The aim of this study was to compare the early functional results of DMC in FNF by DAA versus posterolateral approach (PLA). A prospective study was conducted on a continuous series of patients who received DMC for FNF by DAA or PLA. The primary endpoint was Harris Hip Score and Parker score assessed at the first follow-up visit. Intraoperative complications were collected during hospitalization. One year clinical results and all cause revision rate were also collected. Radiographic data of cup positioning and limb length were evaluated. Fifty-two patients were included in the DAA group and 54 in the PLA group. Two patients were lost to follow-up. The mean age was 72.8 years. There was no significant difference in HHS or Parker score at 3 and 12 months follow up (p=0.6, p= 0.75). DAA was associated with more intraoperative complications with 4 fractures and 1 femoral nerve deficit (p=0.018). There were 3 revisions in the DAA group (1 infection, 1 dislocation, 1 peri prosthetic fracture) and 1 in the PLA group (infection), which was not statistically significant (p=0.34). Cup anteversion was 6° greater and inclination 9° lesser in DAA group (p=0.028, p<0.01). Results suggest that DAA does not provide any early functional benefit in THA-DMC for FNF compared to PLA. It could lead to more intraoperative complications and a higher revision rate. DAA requires an experienced surgeon and careful patient selection

Background. The direct anterior approach (DAA) for total hip arthroplasty (THA) is marketed with claims of superiority over other approaches. Femoral exposure can be technically challenging and potentially lead to early failure. We examined whether surgical approach is associated with early THA failure. Methods. A retrospective review of 478 consecutive early revision THAs within five years of primary THA at three academic centers from 2011 through 2014 was performed. Exclusion criteria resulted in a final analysis sample of 341 early failure THAs. Primary surgical approach was documented for each revision, along with time to revision, and failure etiology. Results. Early femoral component failure was more common with the DAA (49.6%) than the direct lateral (36.6%) and posterior (13.8%) approaches (p = 0.001). In multivariate regression controlling for age, sex, laterality, Dorr bone type, BMI at revision, bilateral procedure (yes/no), and femoral stem type, the DAA remained a significant predictor of early femoral failure (p = 0.001). The majority of early revisions for instability were associated with the posterior approach (47.5%) and the DAA (37.5%) compared to the direct lateral approach (15.9%, p = 0.0002). Conclusions. Despite claims of early recovery and improved outcomes with the DAA, our findings indicate the DAA likely confers greater risk for early femoral failure and, along with the posterior approach, a greater risk of early instability compared to the direct lateral approach following THA

INTRODUCTION. Traditionally, acetabular component insertion in direct anterior approach (DAA) total hip arthroplasty (THA) has been performed using fluoroscopic guidance. Handheld navigation systems can be used to address issues of alignment, cup placement and accuracy of measurements. Previous navigation systems have been used successfully in total knee arthroplasty (TKA) and has now been introduced in THA. We investigated the use of a new accelerometer-based, handheld navigation system during DAA THA to compare it to traditional means. This study aims to determine accuracy of acetabular cup placement as well as fluoroscopy times between two groups of patients. METHODS. Data was prospectively collected for a group of consecutive DAA THA procedures using a handheld navigation system (n=45) by a single surgeon. This was compared to data retrospectively collected for a group that underwent the same procedure without use of the navigation system(n=50). The time for use of the navigation system, including insertion of pins/registration, guiding cup position, and removal of pins, was recorded intraoperatively. Postoperative anteroposterior and cross-table lateral radiographs were used to measure acetabular inclination and anteversion angles. Targeted angles for all cases were 40° ±5 for inclination and 20° ±5 for anteversion. Intraoperative fluoroscopy exposure times were obtained from post-anesthesia care unit radiographs. RESULTS. Mean time of pin insertion/registration, cup positioning and removal was 180.5 seconds, 127.7 seconds and 26 seconds, giving a mean total time of 5.6 minutes. There were no significant differences in mean postoperative acetabular inclination angles between the navigation group as compared to the non-navigation group (39.8° vs 40.6°) (p = .2). There were no significant differences in mean postoperative acetabular anteversion angles between the navigation group as compared to the non-navigation group (24.3° vs 23.7°) (p=.5). Mean intraoperative fluoroscopy exposure times were significantly lower in the navigation group as compared to the non-navigation group (12.6 vs 22.2 seconds) (p<.0001). CONCLUSION. The findings demonstrated that a new handheld navigation system required minimal increase in operative time and was as accurate for cup positioning as fluoroscopically assisted DAA THA. Furthermore, there was a 45% reduction in fluoroscopy exposure time. Reduction in fluoroscopy time will lower radiation exposure for the surgeon and patients

Introduction. The direct anterior approach (DAA) for total hip arthroplasty (THA) has gained popularity in recent years. Potential advantages over other surgical approaches include less postoperative pain, fewer postoperative precautions, and quicker early recovery. It is most commonly performed in the supine position with traction tables or table mounted bone hooks to facilitate exposure. In this study, we describe a reproducible surgical technique for DAA THA in the lateral decubitus position with use of standard THA equipment and report on our results and learning curve. Methods. A prospectively collected hip repository was queried for all primary THA DAA performed in the lateral position by a single surgeon over a 4-year period from the surgeon's first case utilizing the technique. Retrospective chart review was performed to identify complications and revisions. Modified Harris Hip Score (mHHS) was collected pre-operatively and again at 1-year post-operative. Radiographic parameters including were measured on the 1-year postoperative radiographs. Results. Three hundred forty-one hips were identified in patients over 18 years of age with 337 hips meeting our inclusion/exclusion criteria. A total of 257 hips (76%) had a minimum of 1-year follow-up. 212 of 225 hips (94%) with available mHHS data achieved MCID, defined as mHHS change of > 8. Mean surgical time was 88 ± 16 minutes. Radiographic evaluation demonstrated reproducible results with mean radiographic side to side leg length discrepancy of 2.6 ± 5.9mm and femoral offset difference of 0.2 ± 4.9mm. Among patients with adequate postoperative radiographs, 234 of 243 (96%) had acetabular component positions within Lewinnick's safe zone. 3 hips (0.9%) required revision THA within the first year postoperatively. There were no dislocations and there was no learning curve detected in terms of operative time, blood loss, complication rate or acetabular component position. Discussion. Critics of DAA THA cite its long learning curve with increased risk of complications as an argument against its widespread use. In this study, we have described a safe and efficient technique for performing THA via the DAA in the familiar lateral decubitus with the use of a standard operating table, positioning devices and THA instrumentation. Our results demonstrate excellent acetabular component placement and low rates of complications within the first postoperative year. Conclusion. DAA THA can be performed safely and efficiently in the lateral decubitus position without a specialized table or instrumentation. Surgeon familiarity with patient position and instruments using the technique presented here may be associated with a shorter procedural learning curve

INTRODUCTION. The Woodpecker pneumatic broaching system facilitates femoral preparation to achieve optimal primary fixation of the stem in direct anterior hip replacement using a standard operating table. The high-frequency axial impulses of the device reduce excess bone tension, intraoperative femoral fractures and overall operating time. The Woodpecker device provides uniformity and enhanced control while broaching, optimizing cortical contact between the femur and implant and thereby maximizing prosthetic axial stability and longevity. This study aims to describe a single surgeon's experience using the Woodpecker pneumatic broaching system in 649 cases of direct anterior approach (DAA) total hip arthroplasties to determine the device's safety and efficacy. METHODOLOGY. All consecutive patients undergoing elective anterior bikini total hip arthroplasties (THA) performed by a single surgeon between July 2013 and June 2018 were included. Patients undergoing a THA with the use of the Woodpecker device through a different surgical approach, revision THA or arthroplasties for a fractured neck of femur were excluded (n=219). The pneumatic device was used for broaching the femoral canal in all cases. Pre-operative and post-operative Harris Hip Scores (HHS) and post-operative radiographs were analyzed to identify femoral fractures and femoral component positioning at 6 weeks, 6 months and 12 months post-operative. Any intra-operative or post-operative surgical complications and component survivorship until most recent follow up were recorded in the clinical notes. RESULTS. A total of 649 patients (L THA=317, R THA=328 and bilateral=2) with a mean age of 69 (range 46–91yrs) and mean BMI of 28.3 (range = 18.4–44.0) underwent a DAA THA using a Woodpecker device were included in the study. Of these patients, 521 (80%) underwent uncemented and 128 (20%) underwent cemented femoral components. The time taken to broach the femur using Woodpecker broaching this system averaged 2.8 minutes (1.4 to 7.5 minutes) in both cemented and uncemented cases. In 91% of cases the templated broach size was achieved with the remaining 9% within +/− 1 size of the planned template. Radiographic analysis revealed 67.3% of the stems placed in 0–1.82 degrees of varus and 32.7% placed in 0–1.4 degrees of valgus. Average HHS were 24.4 pre-operatively, with drastic improvements shown at 6 weeks (80.95), 6 months (91.91) and 12 months (94.18) after surgery. Intraoperative femoral fractures occurred in three patients (0.4%) during trial reduction, a further three patients had periprosthetic post-operative fractures (0.4%) from falls, two patients had stem subsidence (0.3%) and a further two patients had wound infections (0.3%). At the most recent follow up, the survivorship of the acetabular component was 99.7% and the femoral component was 99.1%, with mean follow up of 2.9 years (0.5 to 5 years). No intraoperative or post-operative complications could be directly attributed to the Woodpecker broaching system. CONCLUSION. The pneumatic Woodpecker device is a safe and effective alternative tool in minimally invasive direct anterior hip replacement surgery for femoral broaching performed on a standard operating table. The skill and experience of the surgeon must be taken into consideration when utilizing new surgical devices