Direct Anterior Approach Total Hip Arthroplasty Research Articles

Direct Anterior Approach Total Hip Arthroplasty for Femoral Neck Fractures in the Lateral Position.

To compare the clinical efficacy of artificial total hip arthroplasty(THA) for femoral neck fracture between direct anterior approach(DAA) in lateral position and posterior lateral approach(PLA). Comparison of 200 cases of patients who underwent THA collected between September 2019 and August 2021 was done. Incision length, intraoperative bleeding, operative time, difference in postoperative haemoglobin from preoperative levels, length of hospital stay, postoperative time to get off the floor, visual analogue score (VAS) for pain, preoperative and postoperative Harris scores for the hip, and measurements of the acetabular abduction angle and anterior acetabular tilt angle at 6 months postoperatively were collected, and all the cases were followed up for at least 2 years. Compared with the PLA group, the DAA group had a shorter incision length, less intraoperative blood loss, less postoperative haemoglobin reduction compared with the preoperative period, a shorter hospital stay and an earlier first time to get off the floor after surgery, however, the comparison of operative times was not statistically significant; Patients in the DAA group had a lower VAS in the early postoperative period compared to PLA; Patients in the DAA group had higher hip Harris scores at 6 weeks and 6 months postoperatively; There was no significant difference in acetabular abduction angle and acetabular anterior tilt angle between the two groups at 6 months postoperatively. Compared to PLA, DAA in THA is minimally invasive, has less pain, less bleeding, earlier time out of bed, shorter hospital stay, better early hip function, faster rehabilitation, and better joint stability.

Collared Cementless Femoral Components Reduce the Revision Rates in Primary Total Hip Arthroplasty Using the Direct Anterior Approach: An Australian Orthopaedic Association National Joint Replacement Registry Study

BackgroundAn increased risk of periprosthetic fracture and aseptic loosening is reported when the direct anterior approach (DAA) is used for total hip arthroplasty (THA), especially with cementless implants. We assessed the rate of revision comparing collared and collarless femoral stems when using the DAA for THA. MethodsWe used data from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) for primary THA for osteoarthritis inserted with the DAA between January 2015 and December 2022. There were 48,567 THAs that used the DAA (26,690 collarless cementless, 10,161 collared cementless, and 11,716 cemented). Cumulative percent revision (CPR) was calculated for all-cause revision, revision for periprosthetic femoral fractures, and aseptic femoral stem loosening. Cox proportional hazard ratios were used to compare the revision of collared and collarless cementless stems. We also compared collared cementless stems and cemented stems. ResultsA higher rate of all-cause revision within three months of surgery was observed with collarless compared to collared cementless implants (HR [hazard ratio]: 1.99 [95% CI (confidence interval), 1.56 to 2.54]; P < 0.001). Similarly, collarless cementless implants were associated with a greater rate of revision for fracture in the first six months (HR: 2.90 [95% CI, 1.89 to 4.45]; P < 0.001) and after 6 months (HR 10.04 [95% CI 1.38 to 73.21]; P = 0.02), as well as an increased rate of revision for aseptic loosening after two years (HR: 5.76 [95% CI, 1.81 to 18.28], P = 0.003). Collared cementless and cemented stems performed similarly. ConclusionCollared stems were associated with a reduced rate of all-cause revision for cementless THA performed via the DAA. The reduction in risk may be due to protection from periprosthetic femoral fracture and aseptic loosening.

A Randomized Clinical Trial of Direct Anterior versus Mini-Posterior Total Hip Arthroplasty: Small, Early Functional Differences Did Not Lead to Meaningful Clinical Differences at 7.5 Years

Our previously reported randomized clinical trial of direct anterior approach (DAA) versus mini-posterior approach (MPA) total hip arthroplasty (THA) showed slightly faster initial recovery for patients who had a DAA and no differences in complications or clinical or radiographic outcomes beyond 8 weeks. The aims of the current study were to determine if early advantages of DAA led to meaningful clinical differences beyond 5 years and to identify differences in midterm complications. Of 101 original patients, 93 were eligible for follow-up at a mean 7.5 years (range, 2.1 to 10). Clinical outcomes were compared with Harris Hip, 12-Item Short Form Health Survey (SF-12), and Hip Disability and Osteoarthritis Outcomes Scores (HOOS) scores and sub-scores, complications, reoperations, and revisions. Harris Hip scores were similar (95.3 ± 6.0 versus 93.5 ± 10.3 for DAA and MPA, respectively, P = 0.79). The SF-12 physical and mental scores were similar (46.2 ± 9.3 versus 46.2 ± 10.6, P = 0.79, and 52.3 ± 7.1 versus 55.2 ± 4.5, P = 0.07 in the DAA and MPA groups, respectively). The HOOS scores were similar (97.4 ± 7.9 versus 96.3 ± 6.7 for DAA and MPA, respectively, P = 0.07). The HOOS quality of life subscores were 96.9 ± 10.8 versus 92.3 ± 16.0 for DAA and MPA, respectively (P = 0.046). No clinical outcome met the minimally clinically important difference. There were 4 surgical complications in the DAA group (1 femoral loosening requiring revision, 1 dislocation treated closed, and 2 wound dehiscences requiring debridement), and 6 surgical complications in the MPA group (3 dislocations, 2 treated closed, and 1 revised to dual-mobility; 2 intraoperative fractures treated with a cable; and 1 wound dehiscence treated nonoperatively). At a mean of 7.5 years, this RCT demonstrated no clinically meaningful differences in outcomes, complications, reoperations, or revisions between DAA and MPA THA.

Is There a Learning Curve for the 5-Year Implant Survival Rate of Total Hip Arthroplasty Using the Direct Anterior Approach With a Traction Table? A Prospective Cohort Study

BackgroundThe direct anterior approach (DAA) for total hip arthroplasty (THA) is attracting attention as a minimally invasive surgery, but the learning curve to master this approach is a concern, and its effect on long-term results is unknown. The purpose of this prospective cohort study was to clarify how the learning curve affects the 5-year results of DAA THA with a traction table. MethodsOf 402 THA cases using DAA with a mobile traction table and fluoroscopy, 249 cases composed of the first 50 cases for each surgeon were assessed during a learning curve, and 153 cases were evaluated after more than 50 cases of experience. ResultsThe 5-year-implant survival rate was 99.2% both during and after the learning curve. The 2-year complication rate in the learning curve group was 8.9 versus 5.9%, which was not statistically significant. The 2-to-5-year complication rates also did not differ between the cohorts (0 versus 0.7%). Both groups demonstrated decreased complication rates when comparing 2-year complications to 2-to-5-year complications. Clinical scores significantly improved by 2 years and were maintained at 5 years in both groups. The cup safe-zone success rates were 96.4% during the learning curve and 98.7% after the learning curve. The stem safe-zone success rates were 97.2% during the learning curve and 96.1% after the learning curve. Surgical time was approximately 20 minutes shorter after the first 50 cases than during the learning curve (70.8 versus 90.6 minutes, P = .001). Intraoperative blood loss was significantly less after the learning curve than during the learning curve. ConclusionsThis study implies that the learning curve affects perioperative results such as surgical time and intraoperative blood loss, but has little effect on short-term results up to 2 years after surgery and no effect on mid-term results from 2 to 5 years after surgery.

Current perspectives of south african orthopaedic surgeons to the direct anterior approach in total hip arthroplasty

Background: Despite the global increase in popularity for the use of the Direct Anterior Approach (DAA) for Total Hip Arthroplasty (THA), the current beliefs and reasons for its use and disuse amongst South African orthopaedic surgeons is not well understood. Objective: To determine the perspectives regarding DAA compared to other surgical approaches to THA. Methods: We conducted an anonymous online survey sent to all current members of the South African Orthopedic Association (SAOA). Results: The response rate was 24.25% (n=194). There were 76 (39.18%) respondents that have performed DAA (DAA Performers) and 118 (60.82%) that have never performed DAA (DAA nonperformers). A proportion of 50% and 11.84% of DAA performers were between 30 to 45 years and older than 60 years of age, respectively (p&lt;0.000). The DAA is the preferred approach to THA for 36.84% (n=28) of DAA performers, whilst 63.16% (n=48) prefer an alternative approach. Both DAA performers who prefer DAA and those who prefer alternative approaches consider DAA more satisfactory for length of hospital stay (p&lt;0.000) and short-term functional outcomes (p=0.002) compared to other surgical approaches. For DAA non-performers, the primary reasons for not performing DAA THA were inexperience in surgical technique (72.09%), increased operative time (12.79%), unsatisfactory outcomes (27.91%) and learning curve (67.44%). There were 5 (18.52%) and 30 (70.33%) surgeons who have been in clinical practice for more than 10 years that do and do not intend to use DAA in the future, respectively (p&lt;0.000). Conclusion: The trends of the adoption of the DAA by South African orthopaedic surgeons show increasing popularity, similar to patterns seen in the United Kingdom and the United States of America. Younger surgeons are more likely to perform the DAA THA whilst more experienced surgeons are less likely to deviate from their current standard of practice.

Evaluation of an Initial Robotic-Assisted Direct Anterior Approach Cohort Receiving a New Short Metaphyseal Filling Collared Femoral Implant

Background: Shorter, metaphyseal-filling collared stems have become popular with the direct anterior approach (DAA), based on their ease of broaching and insertion through less invasive surgical exposures. To aid with the DAA, robotic-assisted technology provides three-dimensional computed tomography (CT) preoperative planning and intraoperative guidance to accurately assess stem version. With other femoral stems, this has been shown to provide more accurate implant planning and improved patient outcomes. The purpose of this study was to understand femoral stem placement predictability and patient outcomes for a newly designed metaphyseal-filling collared stem system through a DAA in combination with a robotic-assisted system during a single surgeon’s initial cases. Materials and Methods: A single high-volume surgeon, experienced with robotic-assisted DAA total hip arthroplasty (THA), adopted the use of a metaphyseal-filling collared stem. Intraoperative data and patient outcomes up to six months postoperative were collected prospectively during the surgeon’s first 123 cases. Student’s t-tests (α=0.05) were used for statistical comparisons. Intraoperative and radiographic assessments were performed for all 123 cases. Results: The estimated version with neck-cut view of the robotic-assisted system was 13.81 ± 3.81°. The final version measurement captured with the robotic-assisted system was 16.56 ± 6.61°. The difference between the estimated version and robotic-assisted measured version was, on average, 2.68 ± 5.7° (p&lt;0.001). The femoral stem sat at the level of the calcar in all but five cases. There were no intraoperative or postoperative periprosthetic fractures. Patients reported significant improvements in reduced Hip dysfunction and Osteoarthritis Outcome Score for Joint Replacement (HOOS-JR), Patient-Reported Outcomes Measurement Information System (PROMIS 10), and Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores throughout their six-month recovery process with no patients reporting a periprosthetic joint infection, fracture, or dislocation. Conclusion: The use of a metaphyseal-filling collared stem with robotic-assisted DAA resulted in adequate stem version when assessed visually and with CT scan assessments. Version estimation values were improved upon over visual assessments when using the robotic system that maps out the proximal femur and the improvement was also demonstrated when compared to the prior literature. This may also be related to the stem’s collar providing a visual guide during stem placement posterior fill of this triple-tapered stem design. Although further follow up is needed to assess longer-term outcomes, at six months postoperatively, patients had significant improvements in patient-reported outcomes with all patients reporting minimal to no restrictions with their THA.

Functional Acetabular Component Positioning During Direct Anterior Approach Hip Arthroplasty Using a Novel Three-Dimensional Virtual Mesh Imaging System With Fluoroscopy

BackgroundOptimal position of total hip arthroplasty (THA) components is critical for joint mechanics and stability. Acetabular component positioning during supine surgery in direct anterior approach (DAA) THA may be different in the standing position postoperatively, which traditional fluoroscopy is unable to predict. A novel 3-dimensional (3D) image analysis technology (IAT) that uses artificial intelligence to measure the tilt and rotation of the pelvis has enabled prediction of component positioning from supine to standing. The purpose of this study was to compare intraoperative fluoroscopy, non–3D-IAT, and 3D-IAT with postoperative standing radiographs to assess the accuracy of component positioning. MethodsFrom 2022 to 2023, 30 consecutive patients (86.6% women, mean age 59 [range, 55 to 67]) undergoing primary DAA THA with the use of the 3D-IAT were identified. A separate cohort of 148 patients from 2020 to 2021 (85% women, mean age 65 [range, 55 to 69]) who underwent DAA THA with non–3D-IAT was used for comparison. Leg length discrepancy (LLD), cup anteversion, and inclination were manually measured on intraoperative fluoroscopic images and digitally measured using IAT. Follow-up evaluation occurred at 1 month with standing pelvis radiographs measured using Ein Bild Röntgen Analyze–Cup software. Measurements were compared via Wilcoxon signed rank tests where P ≤ .05 indicates significantly different measurements. ResultsMedian LLD, inclination, and anteversion measurements via non–3D-IAT and fluoroscopy were significantly different compared to postoperative standing radiographs (P < .001). The 3D-IAT more accurately predicted LLD, abduction, and anteversion, with values not significantly different from postoperative standing measurements (P = .23, P = .93, and P = .36, respectively). ConclusionsThe use of the 3D-IAT during DAA THA allowed for the more accurate prediction of acetabular component position in the standing position postoperatively.

Contribution of the Medial Iliofemoral Ligament to Hip Stability After Total Hip Arthroplasty Through the Direct Anterior Approach

BackgroundDislocation after total hip arthroplasty (THA) is a primary reason for THA revision. During THA through the direct anterior approach (DAA), the iliofemoral ligament, which provides the main resistance to external rotation (ER) of the hip, is commonly partially transected. We asked: (1) what is the contribution of the medial iliofemoral ligament to resisting ER after DAA THA? and (2) how much resistance to ER can be restored by repairing the ligament? MethodsA fellowship-trained surgeon performed DAA THA on 9 cadaveric specimens. The specimens were computed tomography scanned before and after implantation. Prior to testing, the ER range of motion of each specimen to impingement in neutral and 10° of extension was computationally predicted. Each specimen was tested on a 6-degrees-of-freedom robotic manipulator. The pelvis was placed in neutral and 10° of extension. The femur was externally rotated until it reached the specimen’s impingement target. Total ER torque was recorded with the medial iliofemoral ligament intact, after transecting the ligament, and after repair. Torque at extremes of motion was calculated for each condition. To isolate the contribution of the native ligament, the torque for the transected state was subtracted from both the native and repaired conditions. ResultsThe medial iliofemoral ligament contributed an average of 68% (range, 34 to 87) of the total torque at the extreme of motion in neutral and 80% (58 to 97) in 10⁰ of extension. The repaired ligament contributed 17% (1 to 54) of the total torque at the extreme of motion in neutral and 14% (5 to 38) in 10⁰ of extension, restoring on average 18 to 25% of the native resistance against ER. ConclusionsThe medial iliofemoral ligament was an important contributor to the hip torque at the extreme of motion during ER. Repairing the ligament restored a fraction of its ability to generate torque to resist ER.

Surgical Approach and Body Mass Index Impact Risk of Wound Complications Following Total Hip Arthroplasty

BackgroundPrevious studies have suggested that wound complications may differ by surgical approach after total hip arthroplasty (THA), with particular attention toward the direct anterior approach (DAA). However, there is a paucity of data documenting wound complication rates by surgical approach and the impact of concomitant patient factors, namely body mass index (BMI). This investigation sought to determine the rates of wound complications by surgical approach and identify BMI thresholds that portend differential risk. MethodsThis multicenter study retrospectively evaluated all primary THA patients from 2010 to 2023. Patients were classified by skin incision as having a laterally based approach (posterior or lateral approach) or DAA (longitudinal incision). We identified 17,111 patients who had 11,585 laterally based (68%) and 5,526 (32%) DAA THAs. The mean age was 65 years (range, 18 to 100), 8,945 patients (52%) were women, and the mean BMI was 30 (range, 14 to 79). Logistic regression and cut-point analyses were performed to identify an optimal BMI cutoff, overall and by approach, with respect to the risk of wound complications at 90 days. ResultsThe 90-day risk of wound complications was higher in the DAA group versus the laterally based group, with an absolute risk of 3.6% versus 2.6% and a multivariable adjusted odds ratio of 1.5 (P < .001). Cut-point analyses demonstrated that the risk of wound complications increased steadily for both approaches, but most markedly above a BMI of 33. ConclusionsWound complications were higher after longitudinal incision DAA THA compared to laterally based approaches, with a 1% higher absolute risk and an adjusted odds ratio of 1.5. Furthermore, BMI was an independent risk factor for wound complications regardless of surgical approach, with an optimal cut-point BMI of 33 for both approaches. These data can be used by surgeons to help consider the risks and benefits of approach selection. Level of EvidenceLevel III.

Direct Anterior Approach in Total Hip Arthroplasty for Severe Crowe IV Dysplasia: Retrospective Clinical and Radiological Study.

Background and Objectives: total hip arthroplasty (THA) for Crowe IV hip dysplasia poses challenges due to severe leg shortening, muscle retraction and bone stock issues, leading to an increased neurological complication, and revision rate. The direct anterior approach (DAA) is used for minimally invasive THA but its role in Crowe IV dysplasia is unclear. This retrospective study examines if DAA effectively restores hip biomechanics in Crowe IV dysplasia patients with <4 cm leg length discrepancy, managing soft tissue and yielding functional improvement, limb length correction, and limited complications. Materials and Methods: 19 patients with unilateral Crowe IV hip osteoarthritis and <4 cm leg length discrepancy undergoing DAA THA were reviewed. Surgery involved gradual soft tissue release, precise acetabular cup positioning, and stem placement without femoral osteotomy. Results: results were evaluated clinically and radiographically, with complications recorded. Follow-up revealed significant Harris Hip Score and limb length discrepancy improvements. Abductor muscle insufficiency was present in 21%. The acetabular component was accurately placed, centralizing the prosthetic joint's rotation. Complications occurred in 16% of cases, including fractures, nerve issues, and infection. DAA in THA showcased positive outcomes for hip function, limb length, and biomechanics in Crowe IV dysplasia. Conclusions: the technique enabled accurate cup positioning and rotation center adjustment. Complications were managed well without implant revisions. DAA is a viable option for Crowe IV dysplasia, restoring hip function, biomechanics, and reducing limb length discrepancy. Larger, longer studies are needed for validation.

Does Approach Matter in Robotic-Assisted Total Hip Arthroplasty? A Comparison of Early Reoperations Between Direct Anterior and Postero-Lateral Approach

BackgroundThere is no consensus on whether direct anterior approach (DAA) or postero-lateral approach (PLA) total hip arthroplasty (THA) confers a lower risk of postoperative complications. Robotic assistance in THA results in a more consistently accurate component position compared to manual THA. The objective of this study was to compare rates of dislocation, reoperation, revision, and patient-reported outcome measures between patients undergoing DAA and PLA robotic-assisted primary THA. MethodsWe identified 2,040 consecutive robotic-assisted primary THAs performed for primary osteoarthritis, using DAA (n = 497) or PLA (n = 1,542) between 2017 and 2020. The mean follow-up was 18 months. Kaplan-Meier analysis estimated survivorship free of dislocation, reoperation, and revision. Achievement of patient acceptable symptom state and minimum clinically important difference were used to compare changes in the Hip Disability and Osteoarthritis Outcome Score, Joint Replacement (HOOS JR) and Visual Analog Scale. ResultsDislocation was rare in this series (14 in 2,040, 0.7%), including 1 of 497 (0.2%) in the DAA cohort and 13 of 1,542 (0.8%) in the PLA cohort (P = .210). There was no difference in 2-year reoperation-free survivorship (97.8 versus 98.6%, P = .59) or revision-free survivorship (98.8 versus 99.0%, P = .87) at any time point. After controlling for age, sex, and body mass index, there was no difference in dislocation, reoperation, or revision. At 6-week follow-up, after controlling for age, sex, and body mass index, patients in the DAA cohort had higher odds of achieving HOOS JR minimum clinically important difference (odds ratio = 2.01, P = .012) and HOOS JR patient acceptable symptom state (odds ratio = 1.72, P = .028). There were no differences in patient-reported outcome measures by 3 months. ConclusionsFor robotic-assisted primary THA, DAA may confer enhanced early (<6 weeks) functional recovery compared to the PLA, but there was no significant difference in postoperative dislocation, reoperation, or revision rates.

Fluoroscopy Versus Imageless Optical Navigation in Direct Anterior Approach Total Hip Arthroplasty.

Utilization of the direct anterior approach (DAA) for total hip arthroplasty (THA) has risen in popularity. Accurate implant placement is a critical factor that influences patient outcomes. The goal of this study was to compare the accuracy and precision of fluoroscopy with imageless optical navigation in DAA THA. This was a cohort study of 640 consecutive primary DAA THAs performed with intraoperative fluoroscopy (n = 300 patients) or imageless optical navigation (n = 304 patients). Accuracy was compared by measuring acetabular cup inclination, anteversion, and leg-length discrepancy (LLD). The proportion of implants placed within the Lewinnek safe zone and those placed within a more precise target of 40 ± 5° inclination and 20 ± 5° anteversion was evaluated. According to the Lewinnek criteria, there was no difference in the percentage of implants placed within both inclination and anteversion targets (fluoroscopy: 90.3%; navigation: 88.8%, P = 0.519). Using the more precise targets, navigation increased the implants positioned correctly for both inclination and anteversion (fluoroscopy: 50.3%; navigation: 65.6%, P < 0.001). Navigation increased the proportion of implants positioned within the target anteversion zone (fluoroscopy: 71.3%; navigation: 83.8%, P < 0.001) but not inclination (fluoroscopy: 71.9%; navigation: 76.9%, P = 0.147). The mean LLD was higher with the use of fluoroscopy compared with navigation (5.5 mm, standard deviation: 4.1; 4.6 mm, SD: 3.4, P < 0.005). No difference in dislocation rate was observed ( P = 0.643). Both fluoroscopy and imageless optical navigation demonstrated accurate acetabular implant positioning during DAA THA. Navigation was more precise and associated with improved acetabular anteversion placement and restoration of LLD. Navigation is an accurate alternative to fluoroscopy with decreased radiation exposure.

Major complications after total hip arthroplasty with the direct anterior approach at a high-volume Ontario tertiary care centre.

The rate of major surgical complications for high-volume orthopedic surgeons using the direct anterior approach (DAA) in Ontario, Canada, is not known. The purpose of this study was to investigate the rate of major surgical complications after total hip arthroplasty (THA) using DAA performed by experienced orthopedic surgeons at a high-volume tertiary care centre in Ontario. We conducted a retrospective cohort review of primary THA through DAA performed by 2 experienced fellowship-trained surgeons at an academic hospital in London, Ontario, between Jan. 1, 2012, and May 1, 2019. We excluded the first 100 cases to allow for surgeon learning curves. We recorded major surgical complications (intraoperative events, postoperative periprosthetic fractures, dislocation requiring closed or open reduction, implant failure [aseptic loosening or subsidence], early (< 6 wk) deep wound infection requiring irrigation and débridement, late (≥ 6 wk) deep wound infection requiring irrigation and débridement, and wound complications [wound dehiscence, stitch abscess, erythema, hematoma or seroma]) within 1 year of THA. A total of 875 primary DAA THA procedures were included. The rates of surgical complications were 0.9% for intraoperative events, 1.5% for postoperative periprosthetic fractures, 0.8% for implant failure, 0.7% for early deep wound infection, 0.1% for late deep wound infection and 3.2% for wound complications; there were no cases of dislocation. The rate of revision for implant failure within 1 year was 0.1%. Male sex was associated with a greater risk of implant failure (p = 0.01), and having a higher body mass index was associated with both increased rates of infection (p < 0.01) and having a wound complication (p < 0.01). Intraoperative events, postoperative periprosthetic fractures, implant failure, deep wound infection and wound complications accounted for the major surgical complications within 1 year of THA through DAA. The low revision rate suggests that DAA is a safe approach for THA.

Conventional versus lateral fasciotomy for prevention of lateral femoral cutaneous nerve injury in the non-fan-type nerve in total hip arthroplasty with direct anterior approach.

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. 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. 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). 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.

The Anatomical Course of the Femoral Nerve with Regard to the Direct Anterior Approach for Total Hip Arthroplasty

BackgroundFemoral nerve (FN) injury is noted as a serious neurological complication following total hip arthroplasty performed via a direct anterior approach (DAA). Therefore, we aimed to clarify the anatomical course of the FN around the acetabular rim and in relation to retractor placement during DAA. MethodsAccording to standard protocol, a DAA for total hip arthroplasty was performed on 69 hemipelves from formalin-preserved full-body donors. The surgery was halted after retractor placement at the anterior part of the acetabulum. Then dissection was performed to expose the FN and the iliopsoas muscle. Various measurements were taken using a reference line from the anterior superior iliac spine to the acetabulum’s center. A total of 6 measurement points, one every 30° from 0° to 150° along the reference line were used to determine the association between the FN and the retractor tip (RT) and the anterior acetabular rim. ResultsThe mean distance from the RT to the FN was 22.5 millimeters (mm). The distance from the FN to the anterior acetabular rim decreased from 0 to 90°, where it was 18.8 mm, before increasing again to 27.3 mm at 150°. ConclusionsIn our cadaveric study, the FN was within 11 to 36 mm of the RT. Second, we found the FN to be closest to the anterior acetabular rim at 90° and 120°. Accordingly, special care should be taken during retractor placement, and if possible, placement at 90° and 120° avoided.

A neck-sparing short stem shows significantly lower blood loss in total hip arthroplasty compared to a neck-resecting short stem

Short stems are associated with a significantly lower blood loss (BL) compared to straight stems in total hip arthroplasty (THA). Different types of stems differ in design, fixation and level of femoral neck osteotomy. Therefore, we sought to evaluate the difference regarding the perioperative BL between two short stems with different designs in direct anterior approach (DAA). A total of 187 THA performed by a single surgeon were analysed. 107 patients received a neck-resecting (Group A) and 80 patients a neck-sparing short stem (Group B). Blood counts of the day before surgery and of two days after surgery were evaluated. Total blood volume and BL were calculated. Additionally, duration of surgery was analysed. The perioperative BL was significantly lower in Group B (451.4 ± 188.4 ml) compared to Group A (546.6 ± 232.7 ml; p = 0.002). The postoperative haematocrit (31.6 ± 3.7% vs. 30.4 ± 4.4%; p = 0.049) and haemoglobin-level (11.0 ± 1.3 g/dL vs. 10.4 ± 1.5 g/dL; p = 0.002) were significantly higher in Group B. Duration of surgery was significantly shorter in Group B (62.0 ± 11.4 min vs. 72.6 ± 21.8 min; p < 0.001). The use of a neck-sparing short stem leads to a significantly decreased BL compared to a neck-resecting short stem in DAA THA. A less extensively conducted capsular release necessary for optimal femoral exposition might lead to a lower perioperative BL and shorter durations of surgery.

Fluoroscopy-based robotic assistance for total hip arthroplasty improves acetabular cup placement accuracy for obese patients compared to the manual, fluoroscopic- assisted technique.

Patient obesity is a risk factor for poor acetabular cup positioning in total hip arthroplasty (THA). To assess the impact of using a novel, fluoroscopy-based robotic THA system on acetabular cup placement in obese versus non-obese patients. A review of 105 consecutive manual unassisted (mTHA) (47 Obese/58 Non-obese) and 102 robotic-assisted (RA-THA) (50 Obese/52 Non-obese) primary, direct anterior approach THA procedures was conducted. All cases were performed by a single surgeon, for a pre-operative diagnosis of osteoarthritis, avascular necrosis, or rheumatoid arthritis. Obesity was defined as a Body Mass Index (BMI) ⩾ 30 kg/m2. Outcomes included acetabular cup inclination and anteversion, and the proportion of cups within the Lewinnek safe-zone. Obese patients in the mTHA cohort had larger cup inclination angles on average compared to non-obese patients (44.82∘± 6.51 vs. 41.39∘± 6.75; p= 0.009). Obese mTHA patients were less likely to have cup placement within the Lewinnek zone compared to non-obese mTHA patients (0.48 vs. 0.67; p= 0.027). Obesity had no effect on the accuracy of RA-THA. Obesity affects the placement of the acetabular component in manual THA. The novel, fluoroscopy-based robotic THA system in this study demonstrated accurate cup placement regardless of obesity status.

Robotic-assisted total hip arthroplasty utilizing a fluoroscopy-guided system resulted in improved intra-operative efficiency relative to a computerized tomography-based platform.

Robotic-assisted total hip arthroplasty (THA) using a computerized-tomography (CT) based workflow increases surgical time relative to traditional manual technique. The purpose of this investigation was to compare the intra-operative efficiencies of two robotic THA systems: a fluoroscopy-based platform (FL-RTHA) and a contemporary, CT-based (CT-RTHA) platform. A review of 107 consecutive FL-RTHA and 159 CT-RTHA primary, direct anterior approach (DAA) THA procedures was conducted. All cases were performed by one of two surgeons operating at the same institution, for a pre-operative diagnosis of osteoarthritis, avascular necrosis, or rheumatoid arthritis. Primary outcome variables included averages and consistencies (variances) for surgical times and operating room (OR) times. A secondary outcome was to quantify the duration of robot-active phases in the FL-RTHA workflow. The FL-RTHA cohort experienced shorter surgical times (38.71min ± 7.00 vs. 75.33min ± 11.38; p < 0.001) and OR times (101.35min ± 12.22 vs. 156.74min ± 17.79; p < 0.001) compared to the CT-RTHA cohort. Surgical times and OR times were both more consistent in the FL-RTHA cohort compared to the CT-RTHA cohort (p < 0.001). Patients who underwent DAA THA with the assistance of a fluoroscopy-based robotic system experienced shorter and more consistent surgical times and OR times compared to patients who underwent similar DAA THA procedures with a contemporary, CT-based robotic platform.

Perioperative periprosthetic femur fracture associated with direct anterior total hip arthroplasty using metaphyseal fit and fill stem

IntroductionThis study aims to identify radiographic and clinical risk factors of perioperative periprosthetic femur fracture associated with the direct anterior approach (DAA) using a metaphyseal fit and fill stem. We hypothesize stem malalignment with this femoral implant places increased stress on the medial calcar region, which leads to an increased risk of periprosthetic fracture.MethodsWe compared patients with periprosthetic femur fractures following DAA total hip arthroplasty (THA) utilizing the Echo Bi-Metric Microplasty Stem (Zimmer Biomet, Warsaw, IN) to a cohort of patients who did not sustain a periprosthetic fracture from five orthopedic surgeons over four years. Postoperative radiographs were evaluated for stem alignment, neck cut level, Dorr classification, and the presence of radiographic pannus. Univariate and logistic regression analyses were performed. Demographic and categorical variables were also analyzed.ResultsFourteen hips sustained femur fractures, including nine Vancouver B2 and five AG fractures. Valgus stem malalignment, proud stems, extended offset, and patients with enlarged radiographic pannus reached statistical significance for increased fracture risk. Low femoral neck cut showed a trend toward statistical significance.ConclusionPatients undergoing DAA THA using a metaphyseal fit and fill stem may be at increased risk of perioperative periprosthetic fracture when the femoral stem sits proudly in valgus malalignment with extended offset and when an enlarged pannus is seen radiographically. This study identifies a specific pattern in the Vancouver B2 fracture cohort with regard to injury mechanism, time of injury, and fracture pattern, which may be attributed to coronal malalignment of the implant.

The Impact of Total Hip Arthroplasty Surgical Approach on Short-Term Postoperative and Patient-Reported Outcomes.

Background While multiple studies have compared outcomes between the direct anterior approach (DAA) and posterolateral (PL) total hip arthroplasty (THA), the debate over the optimal approach remains. Proponents of the DAA suggest that its muscle-sparing properties and unrestricted rehabilitation facilitate a more rapid return to function. The majority of studies demonstrate that patient-reported outcomes (PROs) are similar between approaches beyond the one-year timeframe, but results are mixed when evaluating earlier time points. The purpose of this study was to compare clinical outcomes and PROs between DAA and PL THAs at six weeks postoperatively. Methods A retrospective review of 749 primary THAs (151 PL, 598 DAA) from March 2020 to November 2022 was performed. All surgeries were performed by one of the five board-certified and fellowship-trained orthopedic surgeons. All patients completed Patient Reported Outcomes Measurement Information System-Physical Function (PROMIS-PF) questionnaires preoperatively and at six weeks postoperatively. A univariate comparison of clinical outcomes (length of stay (LOS), home discharge rate, 90-day ED returns, and readmissions) and six-week PROMIS-PF scores between approaches was performed. Multivariate analysis was performed to evaluate the effect of the approach on outcomes after adjusting for baseline differences between groups. Results Patients undergoing DAA THA experienced significantly shorter average LOS (0.71 vs. 1.36 days, p<0.001), higher rates of home discharge (99.0 vs. 92.1%, p<0.001), and lower rates of 90-day readmissions (0.7 vs. 6.0%, p<0.001) than those undergoing the PL approach. At six weeks postoperatively, DAA patients achieved higher average PROMIS-PF scores (42.2 vs. 39.9, p=0.001). After adjusting for the Charlson Comorbidity Index and baseline physical function, the DAA was significantly associated with shorter LOS (β=-0.52, p<0.001), increased odds of home discharge (OR=5.70, p=0.001), reduced risk of 90-day readmission (OR=0.14, p=0.001), and higher PROMIS-PF scores at six weeks postoperatively (β=1.37, p=0.045). Conclusion In comparison to patients undergoing PL THA, those treated using the DAA experienced improved clinical and PROs over the six-week postoperative period. While both approaches resulted in satisfactory outcomes, these results support the assertion that DAA THA may result in more rapid recovery and return to function.