Total hip arthroplasty (THA) is one of the most successful orthopedic procedures for relieving pain, restoring joint function, and improving quality of life in patients with end-stage hip disorders such as osteoarthritis, avascular necrosis, inflammatory arthritis, and femoral neck fractures [1]. Advances in implant design, perioperative care, and surgical techniques have significantly improved the longevity and functional outcomes of THA, making it the standard treatment for debilitating hip pathology [2]. The choice of surgical approach plays a crucial role in determining postoperative recovery, complication rates, and functional outcomes. Commonly used approaches include the posterior, lateral, anterolateral, and direct anterior approach (DAA). Among these, the DAA has gained considerable popularity because it utilizes an internervous and intermuscular plane, minimizing muscle detachment and preserving soft tissue integrity [3]. The approach was originally described by Hueter in the nineteenth century and later popularized by Smith-Petersen for hip surgery, with modern refinements making it increasingly applicable to contemporary THA [4]. The muscle-sparing nature of the DAA has been associated with reduced postoperative pain, earlier mobilization, shorter hospital stay, and rapid recovery of gait when compared with conventional approaches [5]. Several comparative studies have demonstrated improved early functional outcomes and higher patient satisfaction following DAA, although long-term functional results are generally comparable to other approaches [6,7]. Furthermore, preservation of posterior soft tissues contributes to a lower incidence of postoperative dislocation, while fluoroscopic guidance during surgery may improve component positioning and restoration of hip biomechanics [8]. Despite these advantages, the DAA is technically demanding and has a well-recognized learning curve. During the initial phase of adoption, surgeons may encounter longer operative times and a higher incidence of complications such as lateral femoral cutaneous nerve neuropraxia, intraoperative femoral fractures, and wound-related problems [7,9]. With increasing surgical experience and appropriate patient selection, however, these complication rates decrease substantially and become comparable to those of traditional approaches [7]. As the utilization of the DAA continues to increase worldwide, evaluation of surgical techniques and functional outcomes in different clinical settings is essential to determine its safety, reproducibility, and effectiveness. Therefore, the present case series was undertaken to describe the surgical techniques employed during the direct anterior approach to the hip and to evaluate the early functional outcomes and perioperative results in patients undergoing this procedure. [10] The present study aims to evaluate the surgical techniques and functional outcomes of the Direct Anterior Approach (DAA) for total hip arthroplasty in patients treated at a tertiary care teaching hospital. The objectives are to describe the surgical technique employed, assess postoperative functional outcomes using the Harris Hip Score, evaluate perioperative parameters including operative time, blood loss, hospital stay, and time to mobilization, and determine the incidence of intraoperative and postoperative complications. The study is justified because the Direct Anterior Approach has emerged as a muscle-sparing technique with the potential advantages of faster recovery, reduced postoperative pain, and improved early functional outcomes; however, evidence regarding its safety, reproducibility, and outcomes from Indian tertiary care centers remains limited. The findings of this case series are expected to provide valuable data on the feasibility and effectiveness of the Direct Anterior Approach, support optimization of surgical techniques and patient selection, and serve as a foundation for future comparative studies and long-term evaluation of functional outcomes following total hip arthroplasty.

This retrospective case series will be conducted in the Department of Orthopaedics at a tertiary care teaching hospital and medical college in Ahmedabad, Gujarat, India. The hospital is a high-volume referral center that caters to patients with complex orthopedic disorders from Ahmedabad and surrounding regions. The study will be carried out over a period of one year, from January 2025 to December 2025. All patients who undergo primary total hip arthroplasty (THA) using the Direct Anterior Approach (DAA) during the study period will be screened for eligibility. Consecutive patients fulfilling the inclusion criteria will be enrolled in the study, making the sample size dependent on the number of eligible cases performed during the study period. Patients aged 18 years and above who undergo primary THA using the Direct Anterior Approach and have complete clinical, operative, radiological, and follow-up records with a minimum follow-up duration of six months will be included. Patients undergoing revision THA, THA performed through surgical approaches other than the Direct Anterior Approach, those with incomplete medical records, or those lost to follow-up before six months will be excluded from the study. Data will be collected retrospectively from hospital medical records, operative notes, anesthesia records, radiographs, and outpatient follow-up records using a predesigned case record form. Information regarding demographic characteristics, indication for surgery, side of involvement, operative time, intraoperative blood loss, length of hospital stay, perioperative complications, radiographic parameters, and postoperative rehabilitation will be documented. Functional outcomes will be assessed using the Harris Hip Score (HHS), which will be recorded preoperatively and at the latest follow-up visit. Additional outcome measures will include time to ambulation, component positioning, postoperative complications, and need for revision surgery, if any. The collected data will be entered into Microsoft Excel and analyzed using SPSS version 26.0. Continuous variables will be expressed as mean ± standard deviation or median with interquartile range, whereas categorical variables will be presented as frequencies and percentages. Preoperative and postoperative functional outcomes will be compared using the paired t-test or Wilcoxon signed-rank test, depending on the distribution of data. A p-value of <0.05 will be considered statistically significant. Institutional Ethics Committee approval will be obtained prior to commencement of the study. Patient confidentiality and anonymity will be maintained throughout the study, and all procedures will be conducted in accordance with the ethical principles outlined in the Declaration of Helsinki. CASE SUMMARIES Case 1 A 34-year-old male presented with progressively worsening pain in the right hip, difficulty in walking, and limitation of daily activities for approximately one year. Clinical examination revealed painful restriction of hip movements with an antalgic gait. Radiographic evaluation demonstrated advanced avascular necrosis (Ficat stage IV) of the right femoral head with collapse of the articular surface and secondary degenerative changes. Following failure of conservative management, the patient underwent cementless right total hip arthroplasty through the Direct Anterior Approach (DAA). The procedure was completed successfully without intraoperative complications. Immediate postoperative radiographs demonstrated satisfactory positioning of the acetabular cup and femoral stem with restoration of limb length and appropriate hip biomechanics. Early postoperative rehabilitation was initiated on the first postoperative day. Clinical assessment demonstrated symmetrical lower limb alignment, active hip flexion, comfortable unsupported sitting, and excellent early functional recovery. The anterior surgical incision healed uneventfully with a cosmetically acceptable scar. At follow-up, the patient reported marked pain relief, independent ambulation without assistive devices, and return to routine daily activities without evidence of implant-related complications. Case 2 A 21-year-old male presented with severe pain in the left hip, progressive limp, and restriction of hip movements that significantly affected his mobility and quality of life. Clinical examination demonstrated painful limitation of hip flexion and internal rotation. Preoperative radiographs revealed advanced avascular necrosis of the left femoral head with femoral head collapse and secondary degenerative changes, while the contralateral hip showed early radiological changes without significant functional limitation. The patient underwent cementless left total hip arthroplasty using the Direct Anterior Approach. Surgery was completed without intraoperative complications, and postoperative radiographs confirmed satisfactory alignment of the acetabular and femoral components with stable fixation and restoration of hip biomechanics. Early postoperative rehabilitation included active range-of-motion exercises, straight-leg raising, hip flexion exercises, bed mobility, and progressive sitting. Clinical photographs demonstrated excellent muscle control, restoration of limb alignment, active straight-leg raising, comfortable sitting posture, and good functional recovery during the early postoperative period. The surgical wound healed satisfactorily, and the patient achieved independent ambulation with significant pain relief and improved hip function during follow-up. Case 3 A 68-year-old female sustained a displaced intracapsular fracture neck of the right femur following a low-energy fall. Owing to her active lifestyle and good pre-injury functional status, primary total hip arthroplasty through the Direct Anterior Approach was performed. Operative time was 105 minutes with an estimated blood loss of 300 mL. The patient commenced assisted ambulation on the second postoperative day and progressed well with physiotherapy. At six months, she had regained independent mobility, and the HHS improved from 36 preoperatively to 90 with no evidence of dislocation or infection. Case 4 A 59-year-old male with secondary osteoarthritis following childhood septic arthritis presented with chronic hip pain, limp, and restricted range of motion. Preoperative HHS was 45. Cementless DAA total hip arthroplasty was completed in 95 minutes with blood loss of 280 mL. The postoperative period was notable for transient numbness over the anterolateral aspect of the thigh due to lateral femoral cutaneous nerve neuropraxia, which resolved spontaneously within three months. At final follow-up, the patient had regained painless hip function, and HHS improved to 91. Case 5 A 65-year-old female with end-stage osteoarthritis of the left hip experienced disabling pain, reduced walking capacity, and impaired quality of life despite prolonged conservative treatment. Her preoperative HHS was 40. She underwent cementless total hip arthroplasty using the Direct Anterior Approach with an operative time of 90 minutes and blood loss of 240 mL. Mobilization began on the first postoperative day, and she was discharged after four days. At six-month follow-up, the patient had resumed independent household activities with complete pain relief, and the HHS improved to 96. Case 6 A 57-year-old male with bilateral avascular necrosis underwent staged total hip arthroplasty, with the more symptomatic right hip operated first using the Direct Anterior Approach. The surgery lasted 86 minutes with an estimated blood loss of 210 mL. Rehabilitation progressed smoothly, allowing independent ambulation within two weeks. Radiographic evaluation confirmed satisfactory implant alignment and fixation. At six months, the patient's HHS improved from 46 to 94, and no postoperative complications were observed. Case 7 A 71-year-old female with advanced primary osteoarthritis of the right hip presented with severe pain and progressive limitation of daily activities. Preoperative HHS was 39. Cementless DAA total hip arthroplasty was performed in 98 minutes with blood loss of 270 mL. The patient developed delayed superficial wound healing, which was successfully managed with regular dressing and oral antibiotics without further intervention. Functional recovery was satisfactory, and the HHS improved to 89 at six months. Case 8 A 60-year-old male with ankylosing spondylitis and secondary degenerative arthritis of the right hip presented with marked stiffness, pain, and restricted mobility. His preoperative HHS was 38. Owing to significant soft tissue contracture, the procedure required careful release and lasted 110 minutes with an estimated blood loss of 320 mL. Postoperative rehabilitation resulted in gradual restoration of mobility, and the patient achieved independent ambulation. At six months, HHS improved to 88, and radiographs demonstrated satisfactory implant positioning without complications. Case 9 A 56-year-old female with idiopathic osteonecrosis of the left femoral head underwent cementless DAA total hip arthroplasty after progressive collapse of the femoral head and failure of conservative management. The procedure was completed in 84 minutes with minimal blood loss of 200 mL. She was mobilized within 24 hours and discharged on the fourth postoperative day. At six-month follow-up, the patient reported complete pain relief and unrestricted daily activities. Her HHS improved from 50 preoperatively to 97, with no postoperative complications. Case 10 A 64-year-old male presented with end-stage primary osteoarthritis of the right hip characterized by severe pain, limp, and marked restriction of hip movements. His preoperative HHS was 44. Cementless total hip arthroplasty through the Direct Anterior Approach was performed successfully in 93 minutes with an estimated blood loss of 260 mL. The postoperative recovery was uncomplicated, and full weight-bearing was initiated on the first postoperative day. At six-month follow-up, radiographs confirmed stable implant fixation with appropriate component positioning. The patient regained excellent hip function with an HHS of 94 and returned to normal daily activities without the need for walking aids.

A total of 10 patients underwent primary total hip arthroplasty using the Direct Anterior Approach (DAA) during the study period. The mean age of the patients was 61.6 ± 5.7 years, with an equal distribution of males and females. The most common indication for surgery was primary osteoarthritis (40%), followed by avascular necrosis (30%), secondary osteoarthritis (20%), and fracture neck of femur (10%). The right hip was operated on in 60% of cases. The mean operative time was 94.1 ± 8.2 minutes, with an average estimated blood loss of 255 ± 38 mL. Patients were mobilized early, with a mean time to first ambulation of 1.2 ± 0.4 days, and the average hospital stay was 4.2 ± 0.8 days. No patient required blood transfusion or experienced intraoperative femoral fracture or major neurovascular injury. Functional outcomes showed marked improvement following surgery. The mean Harris Hip Score increased significantly from 42.8 ± 4.5 preoperatively to 92.7 ± 3.2 at six months of follow-up (p < 0.001). Similarly, the mean pain score (VAS) decreased from 8.4 ± 0.8 to 1.2 ± 0.6, while hip flexion improved from 72 ± 11° to 108 ± 8° (p < 0.001 for both). All patients achieved independent ambulation by the final follow-up. Postoperative complications were minimal, with 80% of patients experiencing no complications. One patient (10%) developed transient lateral femoral cutaneous nerve neuropraxia, which resolved spontaneously, and one patient (10%) had delayed superficial wound healing that responded to conservative treatment. There were no cases of deep infection, dislocation, periprosthetic fracture, deep vein thrombosis, or revision surgery. Based on the final Harris Hip Score, 90% of patients achieved excellent functional outcomes, while the remaining 10% had good outcomes, indicating that the Direct Anterior Approach provided excellent early functional recovery with a low complication rate in this case series. Table 1. Baseline Demographic and Clinical Characteristics of Patients (n = 10) Variable Value Age (years), Mean ± SD 61.6 ± 5.7 Gender Male 5 (50.0%) Female 5 (50.0%) Operated Side Right 6 (60.0%) Left 4 (40.0%) Diagnosis Primary Osteoarthritis 4 (40.0%) Avascular Necrosis 3 (30.0%) Fracture Neck of Femur 1 (10.0%) Secondary Osteoarthritis 2 (20.0%) Preoperative Harris Hip Score, Mean ± SD 42.8 ± 4.5 Table 2. Surgical Characteristics and Perioperative Outcomes (n = 10) Variable Mean ± SD / n (%) Operative Time (minutes) 94.1 ± 8.2 Estimated Blood Loss (mL) 255 ± 38 Time to First Ambulation (days) 1.2 ± 0.4 Length of Hospital Stay (days) 4.2 ± 0.8 Cementless Prosthesis Used 10 (100%) Blood Transfusion Required 0 (0%) Intraoperative Femoral Fracture 0 (0%) Intraoperative Nerve Injury 0 (0%) Table 3. Functional Outcomes Following Direct Anterior Total Hip Arthroplasty Variable Preoperative Final Follow-up p-value Harris Hip Score 42.8 ± 4.5 92.7 ± 3.2 <0.001* Independent Ambulation 0 (0%) 10 (100%) <0.001* Pain (VAS Score) 8.4 ± 0.8 1.2 ± 0.6 <0.001* Hip Flexion (°) 72 ± 11 108 ± 8 <0.001* *Paired t-test Table 4. Postoperative Complications and Clinical Outcomes Variable Frequency Percentage (%) No Complications 8 80.0 Transient Lateral Femoral Cutaneous Nerve Neuropraxia 1 10.0 Delayed Superficial Wound Healing 1 10.0 Deep Infection 0 0 Hip Dislocation 0 0 Periprosthetic Fracture 0 0 Deep Vein Thrombosis 0 0 Revision Surgery 0 0 Final Functional Outcome (HHS) Excellent (≥90) 9 90.0 Good (80–89) 1 10.0 Fair/Poor (<80) 0 0 Table 5. Individual Case Summary of Patients Undergoing Direct Anterior Total Hip Arthroplasty Case Age/Sex Diagnosis Side Operative Time (min) Blood Loss (mL) Pre-operative HHS Final HHS Complication 11 34/M Avascular Necrosis (Ficat Stage IV) Right 90 230 47 95 None 12 21/M Avascular Necrosis (Ficat Stage IV) Left 87 210 45 96 None 3 68/F Fracture Neck of Femur Right 105 300 36 90 None 4 59/M Secondary Osteoarthritis Left 95 280 45 91 Transient Lateral Femoral Cutaneous Nerve Neuropraxia 5 65/F Primary Osteoarthritis Left 90 240 40 96 None 6 57/M Bilateral Avascular Necrosis (Right THA) Right 86 210 46 94 None 7 71/F Primary Osteoarthritis Right 98 270 39 89 Delayed Superficial Wound Healing 8 60/M Secondary Osteoarthritis (Ankylosing Spondylitis) Right 110 320 38 88 None 9 56/F Avascular Necrosis Left 84 200 50 97 None 10 64/M Primary Osteoarthritis Right 93 260 44 94 None

The present case series evaluated the surgical technique and early functional outcomes of the Direct Anterior Approach (DAA) for total hip arthroplasty in ten patients. Excellent clinical and functional outcomes were observed, with a significant improvement in the mean Harris Hip Score (HHS) from 42.8 ± 4.5 preoperatively to 92.7 ± 3.2 at six months. Early mobilization, short hospital stay, and a low complication rate were the notable findings of the study. The majority of patients in the present study underwent DAA for primary osteoarthritis (40%), followed by avascular necrosis (30%), secondary osteoarthritis (20%), and fracture neck of femur (10%). Similar indications have been reported in previous studies, where osteoarthritis and avascular necrosis constituted the most common reasons for primary total hip arthroplasty using the anterior approach, reflecting the expanding indications for this muscle-sparing technique [11,12]. The mean operative time in the present series was 94.1 ± 8.2 minutes. This duration is comparable to the findings of Menzies-Wilson et al., who demonstrated acceptable operative times after overcoming the initial learning curve [13]. Likewise, Meneghini et al. emphasized that although DAA may initially require longer operative times, increasing surgical experience substantially reduces operative duration and complication rates [14]. Patients in the current study experienced early postoperative mobilization (1.2 ± 0.4 days) and a mean hospital stay of 4.2 ± 0.8 days. These findings are consistent with the systematic review by Feng et al., which reported significantly shorter hospital stay and faster functional recovery following DAA compared with the posterolateral approach [15]. Similar observations were reported in the meta-analysis by Peng et al., demonstrating earlier ambulation and reduced postoperative pain among patients undergoing DAA [16]. Functional recovery was excellent in the present study, with the mean Harris Hip Score improving from 42.8 to 92.7, and 90% of patients achieving excellent outcomes. These findings are comparable with those reported by Nairn et al., who highlighted excellent early functional recovery following the Direct Anterior Approach once the learning curve was achieved [17]. Similarly, Miller et al. reported favorable early clinical outcomes with DAA while emphasizing that long-term functional outcomes become comparable between different surgical approaches [18]. The overall complication rate in the present series was low. Only one patient (10%) developed transient lateral femoral cutaneous nerve neuropraxia and one patient (10%) experienced delayed superficial wound healing, while no cases of dislocation, deep infection, periprosthetic fracture, deep vein thrombosis, or revision surgery were encountered. These observations are consistent with previous reports indicating that transient lateral femoral cutaneous nerve symptoms are among the most common DAA-specific complications, whereas major complications remain uncommon in experienced hands [19]. Furthermore, Yang et al. reported a relatively higher incidence of lateral femoral cutaneous nerve injury with DAA but lower postoperative pain and dislocation rates compared with the posterior approach [20]. Overall, the findings of the present case series support the growing body of evidence suggesting that the Direct Anterior Approach is a safe and effective technique for total hip arthroplasty. When performed by surgeons familiar with the approach, DAA provides excellent early functional recovery, rapid mobilization, satisfactory implant positioning, and a low incidence of complications, making it an attractive option for appropriately selected patients [11–20].

The present case series demonstrated that the Direct Anterior Approach (DAA) for primary total hip arthroplasty is a safe and effective surgical technique, providing excellent early clinical and functional outcomes. Patients showed significant improvement in Harris Hip Score, substantial pain relief, early postoperative mobilization, and a short hospital stay. The complication rate was low, with only minor self-limiting postoperative events and no cases of dislocation, deep infection, periprosthetic fracture, or revision surgery. These findings suggest that, when performed by experienced surgeons with appropriate patient selection, the Direct Anterior Approach offers reliable implant positioning, rapid rehabilitation, and excellent patient satisfaction. Although the results are encouraging, larger comparative studies with longer follow-up are required to further establish the long-term effectiveness and durability of this approach. LIMITATIONS OF THE STUDY The present study had certain limitations that should be considered while interpreting the findings. First, the study included a relatively small sample size of 10 patients, which limits the generalizability of the results to the broader population undergoing total hip arthroplasty. Being a single-center case series without a comparison group, the study could not directly compare the Direct Anterior Approach with other established surgical approaches such as the posterior or lateral approach. The follow-up period was limited to six months, which was insufficient to evaluate long-term implant survivorship, functional outcomes, and late postoperative complications. As all procedures were performed by a single experienced surgical team, the results may not reflect outcomes achieved during the learning curve or by surgeons with varying levels of expertise. Furthermore, functional assessment was primarily based on the Harris Hip Score, while other validated patient-reported outcome measures and quality-of-life assessments were not included. Long-term radiological parameters, including implant migration, polyethylene wear, osteolysis, and component survival, were not evaluated. Finally, owing to the limited sample size, the study was underpowered to detect uncommon or rare postoperative complications. RECOMMENDATIONS Based on the findings of the present study, larger multicenter prospective studies with adequate sample sizes are recommended to validate the clinical and functional outcomes of the Direct Anterior Approach for total hip arthroplasty. Future research should include comparative studies between the Direct Anterior Approach and other commonly used approaches, such as the posterior and lateral approaches, to better define their relative advantages and limitations. Long-term follow-up is necessary to assess implant survivorship, component longevity, radiological outcomes, and late postoperative complications. Future studies should also incorporate standardized patient-reported outcome measures, quality-of-life assessments, gait analysis, and objective functional evaluations to provide a more comprehensive assessment of patient recovery. Structured surgeon training programs should be encouraged to reduce complications associated with the learning curve of the Direct Anterior Approach. Additionally, further research should evaluate the cost-effectiveness, patient satisfaction, rehabilitation outcomes, and return to daily activities following this approach. Careful patient selection and adherence to standardized surgical techniques and postoperative rehabilitation protocols are recommended to optimize clinical outcomes and minimize perioperative complications

1. Learmonth ID, Young C, Rorabeck C. The operation of the century: total hip replacement. Lancet. 2007;370(9597):1508-19. 2. Evans JT, Evans JP, Walker RW, Blom AW, Whitehouse MR, Sayers A. How long does a hip replacement last? A systematic review and meta-analysis of case series and national registry reports. Lancet. 2019;393(10172):647-54. 3. Kennon RE, Keggi JM, Wetmore RS, Zatorski LE, Huo MH, Keggi KJ. Total hip arthroplasty through the direct anterior approach using a minimally invasive technique. J Bone Joint Surg Am. 2003;85(Suppl 4):39-48. 4. Matta JM, Shahrdar C, Ferguson T. Single-incision anterior approach for total hip arthroplasty on an orthopaedic table. Clin Orthop Relat Res. 2005;441:115-24. 5. Barrett WP, Turner SE, Leopold JP. Prospective randomized study of direct anterior versus posterolateral approach for total hip arthroplasty. J Arthroplasty. 2013;28(9):1634-8. 6. Higgins BT, Barlow DR, Heagerty NE, Lin TJ. Anterior versus posterior approach for total hip arthroplasty: a systematic review and meta-analysis. J Arthroplasty. 2015;30(3):419-34. 7. Cheng TE, Wallis JA, Taylor NF, Holden CT, Marks P, Smith CL, et al. A prospective randomized clinical trial in total hip arthroplasty—comparing early results between the direct anterior approach and the posterior approach. J Arthroplasty. 2017;32(3):883-90. 8. Jewett BA, Collis DK. High complication rate with anterior total hip arthroplasties on a fracture table. Clin Orthop Relat Res. 2011;469(2):503-7. 9. De Geest T, Fennema P, Lenaerts G, De Loore G. Direct anterior total hip arthroplasty: comparative outcomes and contemporary results. World J Orthop. 2015;6(1):94-101. 10. Huo MH, Stockton KG, Mont MA, Parvizi J. What's new in total hip arthroplasty. J Bone Joint Surg Am. 2022;104(9):830-9. 11. Zawadsky MW, Paulus MC, Murray PJ, Johansen MA. Early outcome comparison between the direct anterior approach and mini-incision posterior approach for primary total hip arthroplasty. J Arthroplasty. 2014;29(6):1256-60. 12. Restrepo C, Mortazavi SMJ, Brothers J, Parvizi J, Rothman RH. Hip dislocation: are hip precautions necessary in anterior approaches? Clin Orthop Relat Res. 2011;469(2):417-22. 13. Menzies-Wilson R, Marino IT, Mahalingham K, Field R. Functional outcomes of direct anterior approach hip arthroplasty: oblique "bikini" versus longitudinal skin incision. J Orthop Trauma Rehabil. 2020;27(1):52-6. 14. Meneghini RM, Elston AS, Chen AF, Kheir MM, Fehring TK. Direct anterior approach: risk factor for early femoral failure of cementless total hip arthroplasty. J Bone Joint Surg Am. 2017;99(2):99-105. 15. Feng S, Liu S, Han M, et al. Direct anterior versus posterolateral approaches for clinical outcomes after total hip arthroplasty: a systematic review and meta-analysis. J Orthop Surg Res. 2020;15:231. 16. Peng L, Zeng Y, Wu Y, et al. Clinical, functional and radiographic outcomes of primary total hip arthroplasty between direct anterior approach and posterior approach: a systematic review and meta-analysis. BMC Musculoskelet Disord. 2020;21:338. 17. Nairn LN, Gyemi L, Gouveia K, Ekhtiari S, Patel RV. The learning curve for the direct anterior total hip arthroplasty: a systematic review. Int Orthop. 2021;45(8):1971-82. 18. Miller LE, Gondusky JS, Kamath AF, Boettner F, Wright J, Bhattacharyya SK. Influence of surgical approach on complication risk in primary total hip arthroplasty. Acta Orthop. 2018;89(3):289-94. 19. Yang Y, Hu X, Zhang Q, Wang Y. Direct anterior approach versus posterolateral approach in total hip arthroplasty: a systematic review and meta-analysis of randomized controlled studies. Orthop Surg. 2020;12(3):774-85. 20. Putananon C, Tuchinda H, Arirachakaran A, Wongsak S, Narinsorasak T, Kongtharvonskul J. Comparison of direct anterior, lateral, posterior and posterior-2 approaches in total hip arthroplasty: network meta-analysis. Eur J Orthop Surg Traumatol. 2018;28(2):255-67.