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

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

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

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

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

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