The purpose of our study was to prospectively examine early functional differences in gait between the direct anterior and direct lateral surgical approaches for total hip arthroplasty over the first three months postoperatively. Forty participants were prospectively enrolled to either the direct anterior (20 patients) or direct lateral group (20 patients) based on their surgeon's expertise. Outcome measures were collected preoperatively at their preadmission appointment and postoperatively at discharge from the hospital, two weeks, six weeks and three months. We used the GAITRite® system to measure gait velocity, stride length, single-limb support and single-limb support symmetry. We also had participants complete the Timed Up and Go test and a series of questionnaires at each visit: WOMAC, SF-12, Harris Hip Score, and pain VAS. Our primary outcome, gait velocity, was significantly greater in the direct anterior group at discharge and six weeks postoperatively with adjusted mean differences of 0.12m/s and 0.17m/s respectively. Single-limb support symmetry was also significantly better in the direct anterior group at two weeks, six weeks and three months with adjusted mean differences of 0.10, 0.09 and 0.04 respectively. The direct anterior group also had significantly shorter times to complete the Timed Up and Go test at two and six weeks with adjusted mean differences of −9.02s and −2.64s. There were no differences between the groups at any time point for the WOMAC, SF-12, Harris Hip Score, or pain VAS. Preliminary results of our expertise-based study have found the direct anterior approach to total hip arthroplasty offers better early functional outcomes than the direct lateral approach

Introduction. The direct anterior (DA) approach for total hip arthroplasty has demonstrated successful short term outcomes. However, debate remains about which patients are candidates fo this approach. To our knowledge, there are no studies which specifically investigate short-term outcomes in obese versus non-obese patients undergoing THA through a DA approach. The purpose of this study was to evaluate complication rates and short term outcomes of obese, pre-obese, and normal BMI patients undergoing THA through DA approach. Methods. A retrospective review of 151 consecutive patients who underwent unilateral THA through a DA approach for osteoarthritis or avascular necrosis was performed after IRB approval. Forty patients had a normal BMI, 54 were pre-obese, and 57 were obese by WHO classification (37 class I obese, 12 class II obese, and 8 class III obese). Electronic and paper charts were reviewed to determine differences in surgical time, length of stay, disposition, wound and major complications, and short term outcome measures. Results. When comparing normal and pre-obese patients to a combined group of WHO class I, II, and III obese patients, surgical time was increased by 15.8 minutes (P <0.0001), narcotic use was increased at two weeks (P=0.0242), and assistive device use was increased at 2 weeks (P=0.0079) in the obese patient group. There were trends toward increased wound complications in obese patients, 14.3% vs 4.2% (P=0.0569), increased major complications, 7.1% vs 1.1% (P=0.0633), and a higher use of rehabilitation facilities, 20.0% vs 9.5% (p=0.0676). Conclusions. This study demonstrated significantly increased surgical time and higher use of narcotics and assistive devices in obese patients. Trends toward increased wound and major complications, and a higher likelihood of rehabilitation placement were found. This study helps determine appropriate candidates for THA through a DA approach as obese patients may have more complicated postoperative courses

INTRODUCTION. Cadaveric studies have reported damage to the direct head of rectus femoris and tensor fascia lata muscles with direct anterior approach(DAA) and to the abductors, external rotators with posterior approach(PA). The aim of this prospective study was to evaluate differences in hip muscle strength recovery between DAA and posterior approach (PA) THA. METHODS. Patients with unilateral hip osteoarthritis undergoing THA at a single institution from January 2011 to October 2011 were enrolled. All DAA THA's were performed by one surgeon, and all PA THA's were performed by another surgeon with similar design of components, pain management and rehabilitation protocols. Hip muscle strength was measured with a handheld dynamometer in all planes by a single observer preoperatively, at 6 weeks, 3 months and 6 months. Functional recovery was assessed with the motor component of Functional Independence Measure, UCLA activity score, Harris hip score, SF-12 score. RESULTS. There were 30 patients (15 per group) with similar age, sex, BMI and preoperative functional scores. There was a significant difference between groups in ER strength recovery pattern(p=0.04) with greater mean deficit in PA group from preoperative to 6 weeks(37%), 3 months (28%) and 6 months (25%); whereas DAA group demonstrated 3% mean deficit at 6 weeks, 2% mean improvement at 3 months and 10% mean improvement at 6 months from preoperative values. Flexion strength decreased in DAA group by a mean of 10% at 6 weeks(p=0.07) but improved at 3 months by a mean of 12% as compared to preoperative values. There were no differences in recovery pattern of other hip movements between groups. Functional recovery scores between groups were similar. DISCUSSION. Both DAA and PA THA offer similar recovery in hip muscle strength up to 6 months with exceptions of ER strength deficit in PA group and a trend to flexion strength deficit at 6 weeks in DAA group

Background. Between 1999 and August 2005, we performed Direct Lateral Approach (DLA) in lateral decubitus position as the main approach for primary total hip arthroplasty (THA). After August 2005, we introduced Direct Anterior Approach(DAA) in supine position. Intraoperative target orientation in primary THA was planned in 40–45°cup abduction, 10–20°cup anteversion, and 10–20° stem anteversion. Precice implant positioning has been considered to be very important for postoperative function and stability. The purpose of this study was to compare the DLA and DAA for implant positioning accuracy. Methods. From 1999 to July 2009, we performed 566 primary THAs(78 male, 488 female). The subjects were divided into two groups of 224 DLA and 342 DAA (72 in early stage and 270 in late stage) The difference of the mean age at surgery and preoperative diagnosis among the groups were not significant. We planned to set the cup anteversion at 20°in DAA early stage and 12.5°in late stage DAA due to the development of postoperative dislocation in several cases with early stage DAA. We measured the cup and stem alignment postoperatively using radiography and computed tomography, and measured the combined anteversion angle by Widmer. Statistical analysis was done using the Bartlett Statistical Test and F-test. The results were expressed as median and interquartile range, with an alpha level set at less than 0.05. Results. Cup abduction angle with DLA was 42.7±6.25 °(average±standard deviation), 42.1±4.1°with early stage DAA and 41.9±5.3°with late stage DAA. There was no significant difference between the approaches with average and standard deviation (SD) of cup abduction. The mean cup anteversion with DLA (17.3±10.0°) was significantly smaller than that with early stage DAA(26.6±8.1°) and late stage DAA(21.0±8.0°). SD of cup anteversion with DLA was significantly larger than that with both DAA groups. The mean stem anteversion was significantly smaller with DLA (18.9±14.3) and late stage DAA (16.7±11.1°) than that with early stage DAA (23.5±11.9°). SD of stem anteversion with DLA was significantly larger than that with both DAA groups. There were 9 hips of dislocation: 5 hips in DLA, 3 in early DAA and one in late DAA. SD of combined anteversion Value with DLA(30.5±13.7) was significantly larger than that with early DAA (40.3±12.2) and late DAA (32.7±11.1.∗∗∗∗∗. Conclusion. Significantly less SD for anteversion of stem and cup was demonstrated with DAA compared with DLA. Stable operative positioning with DAA could yield a more accurate and reliable implantation compared with DLA in lateral position. DAA in supine position was a superior approach for primary THA

Background. The anterior approach for total hip arthroplasty has recently been hypothesized to result in less muscle damage. While clinical outcome studies are essential, they are subject to patient and surgeon bias. We prospectively analyzed biochemical markers of muscle damage and inflammation in patients receiving anterior and posterior minimally-invasive total hip arthroplasty to provide objective evidence of the surgical insult. Methods. 29 patients receiving an anterior and 28 patients receiving a posterior total hip arthroplasty were analyzed. Peri-operative and radiographic data were collected to ensure similar cohorts. Creatine kinase, C-reactive protein, Interleukin-6, Interleukin-1beta, and Tumor necrosis factor-alpha were collected pre-operatively, post-operatively, and on post-operative days 1 and 2. Comparisons between the groups were made using the Student's t-test and Fisher's Exact test. Independent predictors of elevation in markers of inflammation and muscle damage were determined using multivariate logistic regression analysis. Results. Markers of inflammation were slightly decreased in direct anterior group (mean differences in C-reactive protein 27.5 [95% confidence interval −24.7–79.6] mg/dL, Interleukin-6 13.5 [95% confidence interval −11.5–38.4] pg/ml, Interleukin-1beta 42.6 [95% confidence interval −10.4–95.6], and Tumor necrosis factor-alpha 148.6 [95% confidence interval −69.3–366.6] pg/ml). The rise in creatine kinase was 5.5 times higher in the post anesthesia care unit (mean difference 150.3 [95% confidence interval 70.4–230.2] units/L, p < 0.05) and nearly twice as high cumulatively in the miniposterior approach group (305.0 [95% confidence interval −46.7–656.8] units/L, p < 0.05). Conclusion. Anterior total hip arthroplasty caused significantly less muscle damage compared to traditional posterior surgery as indicated by creatine kinase levels. The clinical importance of this rise needs to be delineated by further clinical studies. The overall physiologic burden as measured by markers of inflammation, however, appears to be similar. Objective measurement of muscle damage and inflammation provides an unbiased way of determining the immediate effects of surgical intervention in total hip arthroplasty patients

We perform the direct approach using a standard radiolucent operative table with extender at the foot, and the assistance of fluoroscopy. The patient is positioned supine with the pubic symphysis aligned at the table break. The anterior superior iliac spine (ASIS) and center of the knee are marked, and a line drawn between. The incision commences proximally from two finger breadths distal and two finger breadths lateral to the ASIS, and extends distally 8–10 cm. Using fluoroscopy, the anterior aspect femoral neck is located. The incision is placed over the lateral aspect of the greater trochanter, which avoids the lateral femoral cutaneous nerve. The tensor fascia lata is identified, which has a distinctive purple hue, and dissected free from the intermuscular septum lateral to the sartorius and the rectus muscles. The deep, investing aponeurosis of the tensor fascia lata is split using a tonsil. Just below lie the lateral circumflex vessels, two veins and one artery, which must be either ligated or cauterised. A retractor is placed superior to the femoral neck over top of the superior hip capsule. A blunt, cobra-type retractor is then placed along the inferior femoral neck, deep to the rectus muscle and the rectus tendon. A sharp retractor is then used to peel the rectus off from the anterior capsule and placed over the anterior rim of the acetabulum. An anterior capsulectomy is performed. A saw blade is positioned for femoral neck resection and confirmed with fluoroscopy. After resection, acetabular retractors are placed, the socket is reamed, the cup is placed, and position confirmed with fluoroscopy. Turning to the femoral side, the surgeon palpates underneath and around the tensor, around the lateral aspect of the femur, proximal to the gluteus maximus tendon, and places a bone hook around the proximal femur. Femoral preparation and stem insertion require maneuvering the table and adjusting the patient position. The table is “jack-knifed” by lowering the foot of the table to approximately 45 degrees and placing the bed into approximately 15 degrees of Trendelenburg. The contralateral well leg is placed on the padded Mayo stand. A table-mounted femur elevator is attached to the bed, requiring a change in surgical gloves, and attached to the traction hook around the proximal femur. Gentle retraction is placed on the femur to tension the capsule. As the capsule is released the femur will begin to come up/out of the wound and into view. With increasing gentle retraction via the table-mounted hook, the femur is elevated. Simultaneously, the operative limb is externally rotated and adducted underneath the non-operative leg in a lazy “figure of 4” position by the assistant. The use of a “broach-only” stem design is preferred as direct straight reaming of the femur is difficult in most cases. Fluoroscopic images are obtained to confirm femoral implant positioning, offset, neck and leg length. A standardised rapid recovery hospitalization and rehabilitation protocol is used in all cases.

Introduction

Dissemination of Total hip Arthroplasty through the direct anterior approach has, depending upon one's experience and perspective, benefitted from or been plagued by aggressive marketing. Although first developed over 60 years ago it was all but unknown until the past decade. This study exams one community surgeon's experience and thus sheds light on whether the ATHA is a viable operation for all orthopaedic surgeons.

Introduction:

Direct anterior approach (DAA) total hip arthroplasty (THA) has been reported to be a muscle sparing approach. The purpose of this study was to compare gait patterns over time between patients undergoing THA via DAA and posterior approach (PA).

Direct anterior approach (DAA) arthroplasty has generated great interest because of its minimally invasive and muscle sparing nature. Obese patients are reported to be associated with greater incidence of complications in primary joint replacement. The purpose of this study was to compare patient outcomes and complication rates between obese and non-obese patients undergoing primary total hip arthroplasty (THA) through a Bikini direct anterior incision. This retrospective, single surgeon study compared the outcome of 258 obese patients and 200 non-obese patients undergoing DAA THA using a Bikini incision, over a 7-year period. The average follow-up was 4.2 years (range 2.6-7.6 years). There were no statistically significant differences in the complication rate between the two groups. The obese group recorded 2 major (venous thromboembolism and peri-prosthetic fracture) and 2 minor complications (superficial wound infection), compared with the non-obese group, which recorded 2 major (deep-wound infection and peri-prosthetic fracture) and 1 minor complication (superficial wound infection). Patient-reported outcomes (WOMAC and Harris Hip Scores) showed significant post-operative improvements (p < 0.001) and did not differ between the two groups. Bikini DDA THA does not increase the complication rate in obese patients and offers similar clinical improvements compared to non-obese patients. (200 words)

Utilization of C-arm fluoroscopy during direct anterior total hip arthroplasty (THA) is disruptive and potentially increases the risks of patient infection and cumulative surgeon radiation exposure. This pilot study evaluated changes in surgeon C-arm utilization during an initial 10 cases of direct anterior THA in which an imageless computer-assisted navigation device was introduced. This retrospective study includes data from 20 direct anterior THA cases performed by two orthopaedic surgeons (BC; SRE) in which an imageless computer-assisted navigation device was utilized (Intellijoint HIP®; Intellijoint Surgical, Waterloo, ON, Canada). Total C-arm image count was recorded in each case, and cases were grouped in sets of 5 for each surgeon. The mean C-arm image count was calculated for each surgeon, and combined C-arm image counts were calculated for the study cohort. Student's t-tests were used to assess differences. The use of intraoperative C-arm fluoroscopy decreased from a mean of 9.4 images (standard deviation [SD]: 8.6; Range: 3 – 23) to a mean of 2 images (SD: 2.9; Range: 0 – 7) for surgeon BC (P=0.10) and decreased from a mean of 10.75 images (SD: 1.2; range 9 – 12) to a mean of 6.7 images (SD: 8.3; range: 0 – 16) for surgeon SRE (P=0.36). Combined, an overall decrease in intraoperative C-arm image count from a mean of 11.3 images (SD: 6.9; range: 6 – 23) to a mean of 3.7 images (SD: 3.9; range: 0 – 8.5) was observed in the study cohort (P=0.06). The adoption of imageless computer-assisted navigation in direct anterior THA may reduce the magnitude of intraoperative C-arm fluoroscopy utilization; however further analysis is required

Navigation in total hip arthroplasty has been shown to improve acetabular positioning and can decrease the incidence of mal-positioned acetabular components. The aim of this study was to assess two surgical guidance systems by comparing intra-operative measurements of acetabular component inclination and anteversion with a post-operative CT scan. We prospectively collected intra-operative navigation data from 102 hips receiving conventional THA or hip resurfacing arthroplasty through either a direct anterior or posterior approach. Two guidance systems were used simultaneously: an inertial navigation system (INS) and optical navigation system (ONS). Acetabular component anteversion and inclination was measured on a post-operative CT. The average age of the patients was 64 years (range: 24-92) and average BMI was 27 kg/m. 2. (range 19-38). 52% had hip surgery through an anterior approach. 98% of the INS measurements and 88% of the ONS measurements were within 10° of the CT measurements. The mean (and standard deviation) of the absolute difference between the post-operative CT and the intra-operative measurements for inclination and anteversion were 3.0° (2.8) and 4.5° (3.2) respectively for the ONS, along with 2.1° (2.3) and 2.4° (2.1) respectively for the INS. There was significantly lower mean absolute difference to CT for the INS when compared to ONS in both anteversion (p<0.001) and inclination (p=0.02). Both types of navigation produced reliable and reproducible acetabular cup positioning. It is important that patient-specific planning and navigation are used together to ensure that surgeons are targeting the optimal acetabular cup position. This assistance with cup positioning can provide benefits over free-hand techniques, especially in patients with an altered acetabular structure or extensive acetabular bone loss. In conclusion, both ONS and INS allowed for adequate acetabular positioning as measured on postoperative CT, and thus provide reliable intraoperative feedback for optimal acetabular component placement

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

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.”

Introduction. According to the literature, the gait does not return to normal after THA. However, the three-dimensional hip anatomy is usually not assessed before and after surgery. Our hypothesis was that an accurate reconstruction of the hip anatomy, based on a three-dimensional preoperative planning, may normalize the gait after THA. Material and method. 18 consecutive patients, graded Charnley A, aged of 59.3 ±13 years, underwent THA for unilateral primary osteoarthritis using a direct anterior minimal invasive approach. A 3D computerised planning was performed, the implants size and position were chosen in order to restore, the leg length, the off-set, the centre of rotation and the anteversion angles (Figure 1). At 1 year follow up, a 3D gait analysis was performed and included 29 parameters describing the kinetics and the kinematics. Each patient was compared to himself using the contra-lateral healthy hip, as well as to a group of 13 healthy volunteers. Results. The real implants were the same than the ones planned in all the patients. The hip anatomy was restored with a high accuracy: 0.1±3mm for the hip rotation centre, −1.4±3 mm for the leg length and −0.9±3.5mm for the femoral offset. With respect to the gait, there was no significant difference between the operated side and the control-lateral leg. When compared to the control group, all the patients were within the normal range for all the parameters (Figure 2). Discussion and conclusion. The results suggest that the combination of an accurate 3D reconstruction and a direct anterior minimal invasive approach may allow to achieve a normal gait after THA at one year follow up

Introduction. Many authors have described component position and leg length discrepancy (LLD) after total hip arthroplasty (THA) as the most important factors for good postoperative outcomes. However, regarding the relationships between component position and different approaches for THA, the optimal approach for component position and LLD remains unknown. The aims of this study were to compare these factors among the direct anterior, posterolateral, and direct lateral approaches on postoperative radiographs retrospectively, and determine which approach leads to good orientation in THA. Methods. We retrospectively evaluated 150 patients who underwent unilateral primary THA in our department between January 2009 and December 2014, with the direct anterior, posterolateral, or direct lateral approach used in 50 patients each. Patients with significant hip dysplasia (Crowe 3 or 4), advanced erosive arthritis, prevented osteotomy of the contralateral hip, and body mass index (BMI) of more than 30 were excluded. The mean age, sex, and preoperative diagnosis of the affected hip were equally distributed in patients who underwent THA with the different approaches. The mean BMI did not differ significantly among the groups. The radiographic measurements included cup inclination angle, dispersion of cup inclination from 40°, and LLD on an anteroposterior pelvic radiograph, and cup anteversion angle and dispersion of cup anteversion from 20° on a cross-table lateral radiograph postoperatively. We also measured the ratios of patients with both cup inclination of 30–50° and cup anteversion of 10–30° (target zone in our department), femoral stem varus/valgus, and LLD of 10 mm or less. Statistical analyses used an unpaired t-test and Fisher's exact test, with significance set at p<0.05. Results. The mean cup inclination was 36.9±5.1° for direct anterior approach, 40.8±7.5° for posterolateral approach, and 38.5±7.5° for direct lateral approach. Dispersion of cup inclination from 40° was almost identical in the three groups, with no significant differences. The mean cup anteversion was 23.4±5.5° for direct anterior approach, 25.9±9.2° for posterolateral approach, and 24.3±8.6° for direct lateral approach. Dispersion of cup anteversion from 20° differed between direct anterior approach and posterolateral or direct lateral approach (P<0.05 for each). The mean LLD was 1.3±6.6mm for direct anterior approach, 3.0±8.6mm for posterolateral approach, and 2.6±7.4mm for direct lateral approach. The mean LLD did not differ significantly among the three groups. The ratio of patients with both cup inclination of 30–50° and cup anteversion of 10–30° was significantly better for direct anterior approach than for posterolateral or direct lateral approach (78% vs. 52% and 52%, respectively; p<0.05). The ratios of femoral stem varus/valgus and LLD of 10 mm or less did not differ among the groups. Conclusions. The direct anterior approach in THA appeared to have small dispersion of cup anteversion angle and high ratio of cup component position in our target zone compared with the posterolateral and direct lateral approaches. However, the LLD and femoral stem varus/valgus after THA did not differ significantly among the three approaches postoperatively

The accuracy of cup position in total hip arthroplasty is essential for a satisfactory result as malpositioning increases the risk of complications including dislocation, high wear rate, loosening, squeaking, edge loading, impingement and ultimately failure. We studied 173 patients in a single surgeon series of matched cohorts of patients who underwent total hip arthroplasty. Four separate groups were identified comprising of posterior approach +/− navigation and direct anterior approach +/− navigation. We found a significant difference between the direct anterior navigated group and the posterior non-navigated group for both anteversion (p < 0.05, CI −3.86 to −1.73) and inclination (p < 0.05, CI −3.08 to −1.08). 72% of anterior navigated patients fell within 5° of the navigation software set target cup position of 45° inclination and 20° anteversion and 100% were within 10°. Only 30% of posterior non-navigated were within 5° of both anteversion and inclination and 73% were within 10°. There was also a significant difference between the direct anterior navigated and non-navigated group with respect to anteversion only (p < 0.05, CI 1.50 to 1.30). There were no other significant differences between approaches +/− navigation. The direct anterior approach allows ease of access to both anterior-superior iliac spines for navigation and a supine patient allows anteversion and inclination to be measured in the frontal plane. We conclude that the direct anterior approach with navigation improves accuracy of cup position compared to the conventional posterior approach without navigation

This session will be practically oriented, focusing on important surgical decisions and on technical tips to avoid complications. The panel will be polled concerning individual preferences as regards the following issues in primary total hip arthroplasty: 1. Perioperative antibiotics; 2. Blood management and tranexamic acid protocols; 3. Surgical indications: high BMI patients; 4. Surgical approach for primary total hip arthroplasty: indications or preferences for direct anterior, anterolateral, posterior; 5. Acetabular fixation; 6. Tips for optimizing acetabular component orientation; 7. Femoral fixation: (a) Indications for cemented and uncemented implants. Case examples will be used.; (b) Is there still a role for hip resurfacing?; 8. Femoral material and size: (a) Preferred head sizes and materials in different situations.; (b) Is there a role for dual mobility implants in primary THA?; 9. Bearing surface: present role of different bearings. Case examples will be used. 10. Tips for optimizing intraoperative hip stability; 11. Tips for optimizing leg length; 12. Postoperative venous thromboembolism prophylaxis; 13. Heterotopic bone prophylaxis; 14. Postoperative pain management; 15. Hospital discharge: is there a role for outpatient surgery?; 16. Postoperative rehabilitation protocol: weight bearing, role of physical therapy; 17. Postoperative activity restrictions; hip dislocation precautions; 18. Is there value to physical therapy as outpatient after THA?; 19. Long-term antibiotic prophylaxis for procedures

Acetabular implant position is important for the stability, function, and long-term wear properties of a total hip arthroplasty (THA). Prior studies of acetabular implant positioning have demonstrated a high percentage of outliers, even in experienced hip surgeons, when conventional instruments are used. Computer navigation is an attractive tool for use in (THA, as it has been shown to improve the precision of acetabular component placement and reduce the incidence of outliers. However, computer navigation with imageless, large-console systems is costly and often interrupts the surgeon's workflow, and thus, has not been widely adopted. Another method to improve acetabular component positioning during THA is the use of fluoroscopy with the direct anterior approach. Studies have demonstrated that the supine position of the patient during surgery facilitates the use of fluoroscopic guidance, thus improving acetabular component position. A handheld, accelerometer based navigation unit for use in total hip replacement has recently become available to assist the surgeon in positioning the acetabular component during anterior approach THA, potentially reducing the need for intraoperative fluoroscopic studies. We sought to compare the radiographic results of direct anterior THA performed with conventional instrumentation vs. handheld navigation to determine the accuracy of the navigation unit, and to see whether or not there was a reduction in the fluoroscopic time used during surgery. Furthermore, we timed the use of the navigation unit to see whether or not it required a substantial addition to surgical time. Our results demonstrate that a handheld navigation unit used during anterior approach THA had no difference with regard to acetabular cup positioning when compared to fluoroscopically assisted THA, but led to a reduction in the use of intraoperative fluoroscopy time

Background. There is increasing impetus to use rapid recovery care pathways when treating patients undergoing total hip arthroplasty (THA). The direct anterior (DA) approach is a muscle sparing technique that is believed to support these new pathways. Implants designed for these approaches are available in both collared and collarless variations and understanding the impact each has is important for providing the best treatment to patients. Purpose/Aim of Study. This study aims to examine the role of implant design on implant fixation and patient recovery. Materials and Methods. Patients (n=50) with unilateral hip OA who were undergoing primary DA THA surgery were recruited pre-operatively to participate in this prospective randomized controlled trial. All patients were randomized to receive either a collared (n=25) or collarless (n=25) cementless, fully hydroxyapatite coated femoral stem. Patients were seen at nine appointments (pre-operative, <24 hours post-operation, two-, four-, six-weeks, three-, six-months, one-, and two-years). Patients underwent supine radiostereometric analysis (RSA) imaging <24 hours post-operation prior to leaving the hospital, and at all follow-up appointments. Patients also completed an instrumented timed up-and-go (TUG) test using wearable sensors at each visit, excluding the day of their surgery. Participants logged their steps using Fitbit activity trackers and a seven-day average prior to each visit was recorded. Findings/Results. Twenty-two patients that received a collared stem and 27 patients that received a collarless stem have been assessed. There were no demographic differences between groups. From <24 hours to two weeks the collared implants subsided 0.90 ± 1.20 mm and the collarless implants subsided 3.80 ± 3.37 mm (p=0.001). From two weeks to three months the collared implants subsided 0.67 ± 1.61 mm and the collarless implants subsided 0.45 ± 0.46 mm (p=0.377). Step count was reduced at two weeks to 3108 ± 1388 steps for collared patients and 2340 ± 1685 steps for collarless patients (p=0.072). Step count was increased at three months to 8939 ± 3494 steps for collared patients and 6114 ± 2529 steps for collarless patients (p=0.034). TUG test time was increased at two weeks compared to pre-operatively by 3.45 ± 6.01 s for collared patients and 2.29 ± 4.92 s for collarless patients (p=0.754). TUG test time decreased from two weeks to three months by 6.30 ± 6.05 s for collared patients and 5.68 ± 4.68 s for collarless patients (p=0.922). Conclusions. Collared implants subsided less in the first two weeks compared to collarless implants but subsequent subsidence after two weeks was not significantly different. Presence of a collar on the stem impacted patient activity but not function. This suggests that both the implant design as well as the surgical technique may play a role in the patient's early post-operative experience

BACKGROUND. The obesity crisis in the United States has caused a significant increase of hip arthritis. Surgical complication rates are higher in this population and guidelines are being used to select patients who are acceptable candidates for surgical intervention. This retrospective study evaluated the complication rates for obese patients undergoing total hip replacement compared to non-obese patients as defined by the World Health Organization (WHO). Additionally, we compared complication rates of the direct anterior approach (ATHA) versus the posterior approach (PTHA) in a consecutive group of patients using similar protocols. METHODS. This study is an IRB approved retrospective review of 210 patients undergoing ATHA and 201 patients undergoing PTHA during the same time period by 2 experienced, high-volume total joint surgeons. Non-obese patients were compared to obese patients using WHO body mass index (BMI) classification. Minor and major complications were reviewed as well as surgical time, length of stay, disposition, and short-term outcome measures (including pain scores, narcotic use, and assistive device use). RESULTS. The non-obese cohort (BMI < 30) had lower complication rates (2.8% major, 4.4% minor) when compared to the obese cohort (8.7% major, 9.9% minor). Major complications by obese class were as follows: Class I 8.6%, Class II 7.1% and Class III 11.5%. The non-obese ATHA cohort had lower complication rates (0.8% major, 5.0% minor) compared to the PTHA cohort (5.0% major, 6.7% minor). ATHA obese patients had 6.3% major and 9.9% minor complication rates, compared to 11.1% major and 10.0% minor complication rates in PTHA. Lastly, the evaluation of short term outcomes showed more favorable results for ATHA compared to PTHA for both obese and non-obese patients. CONCLUSION. Obesity was associated with an increased risk of complications and less favorable short-term outcomes following THA. Direct anterior THA was also associated with lower complication rates and more favorable short-term outcomes