The less invasive anterior approach for total hip arthroplasty: a comparison to other approaches and an evaluation of the learning curve - a systematic review

The effect of 3 commonly used surgical approaches for total hip arthroplasty on mid- to long-term patient-reported outcome measures

INTRODUCTION

The most effective surgical approach for total hip arthroplasty (THA) remains controversial. Comparisons of surgical approach based on patient-reported outcome measures (PROMs) have been limited to short- to mid-term outcomes or the comparison of only 2 approaches. The aim of this study was to compare PROMs for the 3 main approaches for THA with up to 10 years follow-up.

METHODS

A total of 906 patients who underwent primary THA at a single hospital between 2009 and 2020 through an anterior (312), lateral (211) or posterior (383) approach were evaluated using the Oxford Hip Score (OHS), EuroQoL-5-Dimension (EQ-5D-5L) and visual analogue scale/verbal rating scale for pain (VAS/VRS). PROMs were prospectively collected before surgery and routinely at 6 weeks, 6 months and 1, 2, 5 and 10 years after surgery.

RESULTS

There was no significant difference in demographics or comorbidities between the 3 groups. All 3 approaches resulted in a significant improvement in overall PROMs after THA, and plateaued after 6 months postoperatively, with no difference between the approaches (OHS, p < 0.01;EQ-5D-5L Index, p < 0.01;VAS/VRS, p < 0.01). The EQ-5D-5L mobility dimension showed that the lateral approach resulted in 20% more patients reporting problems with mobility than the posterior and anterior approaches at the 6-week, 6-month, 2-year and 10-year follow-up.

CONCLUSIONS

This study shows that all 3 common THA approaches substantially and similarly improve the OHS, EQ-5D-5L Index and VRS between 6 months and 10 years postoperatively. However, patient-reported mobility was poorer after a lateral approach and continued to be so at long-term follow-up.

The Direct Superior Approach in Total Hip Arthroplasty: A Systematic Review

BACKGROUND

Evolution of the surgical approach for total hip arthroplasty (THA) has led to the development of the minimally invasive direct superior approach (DSA). It is hypothesized that the DSA reduces postoperative pain and hospital length of stay (LOS). We aimed to provide an overview of current evidence on clinical, functional, and radiological outcomes with respect to risk of revision, complications, pain scores, physical function, operative time, LOS, blood loss, radiological outcomes, and learning curve.

METHODS

A comprehensive search of Medline, Embase, Web of Science, Cochrane Central Register of Controlled Trials, and Google Scholar, reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses literature search extension guidelines, was conducted to identify studies evaluating clinical, functional, and radiological outcomes of the DSA. Quality assessment was performed using the Cochrane Risk of Bias tool and Newcastle-Ottawa Scale. The review protocol was prospectively registered in the International Prospective Registry of Systematic Reviews.

RESULTS

Seventeen studies were included, generally of moderate quality. Qualitative synthesis evidenced accurate implant positioning, short LOS, and a short learning curve. Conflicting findings were reported for postoperative complications compared with conventional approaches. Better functional outcomes were seen in the early postoperative period than the posterolateral approach (PLA). Outcomes such as blood loss and operative time exhibited conflicting results and considerable heterogeneity.

CONCLUSION

Based on moderate-certainty evidence, it is uncertain if the DSA provides short-term advantages over conventional approaches such as PLA. There is limited evidence on long-term outcomes post-THA using the DSA. Further studies and ongoing registry monitoring is crucial for continuous evaluation of its long-term outcomes.

LEVEL OF EVIDENCE

Level III. See Instructions for Authors for a complete description of levels of evidence.

A Comparative Study of Bipolar Hemiarthroplasty for Intertrochanteric Fracture: Direct Anterior Approach versus Conventional Posterolateral Approach

Purpose

The aim of this study was to compare short-term results from use of the direct anterior approach (DAA) and the conventional posterolateral approach (PLA) in performance of bipolar hemiarthroplasty for treatment of femoral intertrochanteric fractures in elderly patients.

Materials and Methods

A retrospective review of 100 patients with intertrochanteric fractures who underwent bipolar hemiarthroplasty was conducted. The PLA was used in 50 cases from 2016 to 2019; since that time we have used the DAA in 50 cases from 2019 to 2021. Measurements of mean operative time, blood loss, hospitalization period, and ambulation status, greater trochanter (GT) migration and stem subsidence were performed. And the incidence of complications was examined.

Results

Operative time was 73.60±14.56 minutes in the PLA group and 79.80±8.89 minutes in the DAA group (P<0.05). However, after experiencing 20 cases using DAA, there was no statistically difference in operative time between two groups (P=0.331). Blood loss was 380.76±180.67 mL in the PLA group and 318.14±138.51 mL in the DAA group (P<0.05). The hospitalization was 23.76±11.89 days in the PLA group and 21.45±4.18 days in the DAA group (P=0.207). In both groups, there were no progressive GT migration, intraoperative fractures or dislocations, although there was one case of infection in the PLA group.

Conclusion

Although use of the DAA in performance of bipolar hemiarthroplasty required slightly more time in the beginning compared with the PLA, the DAA may well be an alternative, safe surgical technique as a muscle preserving procedure in elderly patients with intertrochanteric fractures.

Accuracy of Positioning and Risk Factors for Malpositioning Custom-Made Femoral Stems in Total Hip Arthroplasty-A Retrospective Multicenter Analysis

Total hip arthroplasty (THA) is commonly performed using off-the-shelf implants. In the case of a severe mismatch between the anatomy of the proximal femur and the geometry of the stem, the use of custom-made stems might become necessary. The goal of this study was to investigate the precision of the implantation of custom-made stems of one manufacturer (CTX stem, AQ Implants) and to determine risk factors for malpositioning. All patients receiving a custom-made CTX stem between 2014 and 2020 at six high-volume academic centers were retrospectively recruited. The achieved position of the stem, as determined by stem version, stem coronal angle, and implantation depth on radiographs, was compared to the plan. The influence of radiographic and demographic parameters on the position was investigated. The results revealed a high variability of the achieved implant position in relation to the preoperative plan. While the stem coronal angle only differed slightly from the intended position, the stem version and the implantation depth showed a high frequency and amount of deviation. Right stems showed significantly higher positions than planned. Surgeons must be aware of this potential problem when implanting custom-made stems.

Is outcome of total hip arthroplasty for hip fracture inferior to that of arthritis in a contemporary arthroplasty practice?

INTRODUCTION

Outcome of total hip arthroplasty (THA) for femoral neck fractures (FNF) has been associated with higher complication rates. However, THA for FNF is not always performed by arthroplasty-surgeons. This study aimed to compare THA outcomes for FNF to osteoarthritis (OA). In doing so, we described contemporary THA failure modes for FNF performed by arthroplasty surgeons.

METHODS

This was a retrospective, multi-surgeon study from an academic center. Of FNF treated between 2010 and 2020, 177 received THA by an arthroplasty-surgeon [mean age 67 years (range, 42 to 97), sex: 64.4% women]. These were matched (1:2) for age and sex with 354 THAs performed for hip OA, by the same surgeons. No dual-mobilities were used. Outcomes included radiologic measurements (inclination/anteversion and leg-length), mortality, complications, reoperation rates and patient-reported outcomes including Oxford Hip Score (OHS).

RESULTS

Post-operative mean leg-length difference was 0 millimeters (mm) (range, -10 to -10 mm), with a mean cup inclination and anteversion of 41 and 26° respectively. There was no difference in radiological measurements between FNF and OA patients (p=0.3). At 5 years follow-up, mortality rate was significantly higher in the FNF-THA compared to the OA-THA group (15.3 vs. 1.1%; p<0.001). There was no difference in complications (7.3 vs. 4.2%; p=0.098) or reoperation rates (5.1 vs. 2.9%; p=0.142) between groups. Dislocation rate was 1.7%. OHS at final follow-up was similar [43.7 points (range, 10 to 48) vs. 43.6 points (range, 10 to 48); p=0.030].

CONCLUSION

Total hip arthroplasty for the treatment of FNF is a reliable option and is associated with satisfactory outcomes. Instability was not a common reason of failure, despite not using dual-mobility articulations in this at-risk population. This is likely due to THAs being performed by the arthroplasty staff. When patients live beyond 2-years, similar clinical and radiographic outcomes with low rates of revision can be expected, comparable to elective THA for OA.

Outpatient total hip arthroplasty does not increase complications and readmissions: a meta-analysis

BACKGROUND

There is no consensus about the safety of outpatient total hip arthroplasty (THA). Therefore, the purpose of this meta-analysis was to quantitatively evaluate and compare outpatient and inpatient THA studies in terms of complication and readmission rates.

METHODS

A systematic search of the literature was performed on 26 July 2019 on PubMed, Web of Science, Cochrane library, and on the grey literature databases. The papers thus collected were used for a meta-analysis comparing outpatient and inpatient THA in terms of complication and readmission rates. Risk of bias and quality of evidence were defined according to Cochrane guidelines. The PRISMA guidelines were used to determine which papers to include in this study.

RESULTS

The literature search resulted in 2317 articles; of these, 8 articles were used for the meta-analysis. A total of 66,971 patients were included, of which 1428 were THA outpatients. The overall complication rate for outpatient THAs was 3.0%, while inpatient THAs had an overall complication rate of 4.7%. The readmission rate was 1.4% in outpatient THAs and 3.0% in inpatient THAs. Only 6 studies reported the number of deaths, which ranged from 0% to 0.01%. The included studies present a moderate risk of bias and, according to GRADE guidelines, the level of evidence for complications and readmissions is very low.

CONCLUSIONS

This meta-analysis documented that outpatient THA is a feasible approach since it does not increase complications or readmissions with respect to inpatient THA, but the available studies present a moderate risk of bias and the quality of evidence of these findings is very low. Future high-level studies are needed to confirm results and indications for outpatient THA.

A comparative of a single novice surgeon's direct anterior approach and posterior approach learning curves in total hip arthroplasty: a retrospective cohort study

INTRODUCTION

The purpose of the present study was to compare a novice surgeon's learning curves with the direct anterior approach and posterior approach in total hip arthroplasty.

METHODS

A consecutive series of 376 total hip arthroplasties performed from November 2014 to September 2019 in a level-one healthcare center by a single surgeon (V.B) were retrospectively studied. Demographic data, functional outcomes, and complications were collected and compared.

RESULTS

Within the ranks of the patients studied, we found differences between groups with respect to dislocation rate and length of stay; these were lower in the direct anterior approach (DAA) group. The approach was not associated with an increase in complications, but rather with a decrease in the rate of dislocations and better functional outcomes at 1-year follow-up. Operative time was initially higher with this approach, but equalized during the learning curve.

CONCLUSION

The DAA can be safe even in the early stages of a novice surgeon's learning curve. It does not present a higher complication rate than the posterior approach, either in infection rate or in periprosthetic fractures. However, the DAA may provide greater functionality, lower dislocation rate and a shorter hospital stay. It can also be concluded that after having performed a certain number of interventions, operative time for the DAA can be comparable to that of other approaches.

Anterolateral minimally invasive hip approach offered faster rehabilitation with lower complication rates compared to the minimally invasive posterior hip approach-a University clinic case control study of 120 cases

INTRODUCTION

The surgical approach used in total hip arthroplasty (THA) has been identified as a factor affecting the outcome. In our University Hospital, the posterior surgical approach is the gold standard. The Rottinger approach is an anterolateral approach which is truly minimally invasive, as it does not vertically cut any muscle fibers. The objective of this study was to determine the difference in surgical outcomes between the posterior hip approach and the Rottinger approach which was newly adopted at our Hospital.

METHODS

In a retrospective study, a total of 120 patients underwent THA; 60 patients using the Rottinger approach by the young consultant surgeon and another 60 patients using the standard posterior approach by the senior orthopaedic surgeon. Patients have been controlled for age, gender, and ASA grades. All preoperative demographic data showed no significant difference between the control and study groups. The following parameters were analyzed: incision length, duration of the surgery, intraoperative blood loss, WOMAC index, Harris Hip Score, range of motion at 3 and 12 months after surgery, time of quitting the crutches, and willingness for the contralateral hip arthroplasty.

RESULTS

WOMAC index, surgical time, and incision lengths have been without significant difference in both approaches. Intraoperative blood loss was significantly lower in the Rottinger group (CI:  - 10.903,  - 0.064). Harris Hip score was significantly higher (CI: 4.564, 12.973) in the Rottinger group at 3 months, but similar (CI:  - 3.484, 2.134) at 12 months follow-up. At 3 months, active flexion and extension were significantly higher in the Rottinger group (CI: 0.595, 8.239; 2.487, 4.480, respectively), and active abduction and passive adduction (CI:  - 5.662,  - 0.338;  - 6.290,  - 1.410, respectively) in the posterior approach group. Patients in the Rottinger approach group on average quit crutches 3 weeks earlier and had no postoperative dislocations compared to 2 dislocations in the control group.

CONCLUSION

The Rottinger approach offered faster rehabilitation with less need for crutches and with lower complication rates.

Satisfactory clinical and radiologic outcomes with a new shorter and modular stem for end-stage hip osteoarthritis: an international prospective multicentre pilot study

Introduction: This multicenter prospective cohort study aimed to assess the safety and clinical and radiologic performance of the CLS® BreviusTM Stem with Kinectiv® Technology. Material and Methods: A total of 222 consecutive subjects, recruited in five different centers, qualifying for primary total hip arthroplasty (THA), were enrolled in the study. All the subjects received the CLS® BreviusTM Stem with Kinectiv® Technology. All the enrolled study subjects underwent pre-operative clinical and radiographic evaluation. Additionally, all subjects underwent post-operative clinical, functional and radiographic evaluations at 6 months and 1, 2, 3, and 5 years. These evaluations included implant survival, pain and functional performance (Harris Hip Score [HHS], University of California, Los Angeles [UCLA] Activity Score, Oxford Hip Score), subject quality-of-life (EQ-5D), radiographic parameters, complications, and concentration of metal ions (aluminum and titanium) in blood. Results: No revisions were performed during the follow-up period. Of the 222 patients, only 76 completed the 5-year follow-up. Only 7 and 5 patients had aluminum and titanium 5-year evaluations, respectively. All the clinical parameters showed an overall improvement in the overtime measured with ANOVA for repeated measures; furthermore, the clinical scores showed a statistically significant improvement at 5 years with respect to pre-operative value (p < 0.001). Aluminum and titanium showed no variation for repeated measures at different time points (p > 0.05). A total of six complications were reported, of which only two were hip-related. Conclusions: The function of the CLS® BreviusTM Stem with Kinectiv® Technology indicated that subject well-being significantly increased following THA regardless of age, gender, BMI, previous surgery, primary diagnosis, and lifestyle.

Direct Anterior Approach for Total Hip Arthroplasty in the Elderly with Femoral Neck Fractures: Comparison with Conventional Posterolateral Approach

BACKGROUND

The aim of this study was to determine if it was feasible and safe to perform total hip arthroplasty (THA) using the direct anterior approach (DAA) when compared with the conventional posterolateral approach (PA) in patients with femoral neck fractures. The time required to start walking was investigated to identify advantages of the muscle-sparing approach. Safety of the approach was judged based on the incidence and nature of all complications.

METHODS

We retrospectively reviewed 67 THA cases due to femoral neck fractures from October 2015 to January 2019. The PA was used in 31 cases, and the DAA was used in 36 cases. The average operative time and amount of bleeding were evaluated. Cup inclination, anteversion, and leg length discrepancy (LLD) were also measured on radiographs. The time to start walking and complications (e.g., intraoperative fracture, infection, and dislocation) were recorded.

RESULTS

The mean operative time was 84.35 ± 13.95 minutes in PA group and 99.22 ± 20.33 minutes in DAA group (p = 0.010). But after experiencing 20 cases using the DAA, there was no statistically significant difference in the operative time between the groups. The mean volume of bleeding was 428.73 ± 207.26 mL in the PA group and 482.47 ± 150.14 mL in the DAA group. There was no difference in the acetabular cup position between two groups. Ambulation was started at 3.94 days after surgery on average in the PA group and 3.14 days in the DAA group, showing a statistically significant difference. Intraoperative fracture and infection were not observed in either group. The incidence of LLD was 1 in each group. The dislocation rate was 3.2% (1 case) in the PA group and 5.5% (2 cases) in the DAA group.

CONCLUSIONS

Although the DAA for THA was similar to the PA in terms of operative time, volume of bleeding, and complications, the DAA showed a great advantage in early rehabilitation as a muscle-sparing procedure in the elderly with femoral neck fractures.

MRI Assessment of Muscle Damage After the Posterolateral Versus Direct Anterior Approach for THA (Polada Trial). A Randomized Controlled Trial

BACKGROUND

There is controversy in literature whether the direct anterior approach (DAA) results in less muscle damage compared with the posterolateral approach (PLA) for total hip arthroplasty. The aim of this randomized controlled trial was to assess muscle damage between these two approaches.

METHODS

Forty-six patients were included. Muscle atrophy, determined with the Goutallier classification, and muscle surface of twelve muscles were analyzed on magnetic resonance imaging images made preoperatively and one year postoperatively. Differences in component placement after DAA or PLA were assessed on radiographs. Harris hip scores and Hip disability and Osteoarthritis and Outcome Score were used as functional outcomes.

RESULTS

External rotator musculature was damaged in both approaches. After PLA, the obturator muscles showed significantly more atrophy and a decrease in muscle surface. After DAA, the tensor fascia latae showed an increased muscle atrophy and the psoas muscle showed a decreased muscle surface. An increase in muscle surface was seen for the rectus femoris, sartorius, and quadratus femoris after both approaches. The muscle surface of the gluteus medius and iliacus was also increased after PLA. No difference in muscle atrophy was found between the approaches for these muscles. The inclination angle of the cup in PLA was significantly higher. No differences were found in functional outcomes.

CONCLUSION

Different muscle groups were affected in the two approaches. After PLA, the external rotators were more affected, whereas the tensor fascia latae and psoas muscles were more affected after DAA.

Do Patients With Higher Preoperative Functional Outcome Scores Preferentially Seek Direct Anterior Approach Total Hip Arthroplasty?

Background

There is focus on the direct anterior approach (DAA) for total hip arthroplasty because of perceived postoperative functional improvement. We compared baseline, short-term, and long-term outcomes between the DAA and the posterior approach focusing on baseline function.

Material and methods

Multivariate linear and logistic regression models were used to analyze prospective data on 1457 total hip arthroplasties comparing baseline characteristics, operative time, 90-day reoperation, length of stay (LOS), extended LOS (>3 days), and facility discharge. The Patient-Reported Outcome Measurement Information System-Global Health (PROMIS-10) was used to determine physical component score (PCS) and mental component score (MCS), with clinically significant improvement defined as >5 points. Adjusters included age, sex, race/ethnicity, year, Charlson Comorbidity Index, body mass index, alcohol, and tobacco use.

Results

DAA patients had higher preoperative MCS (DAA 50.4 vs posterior approach 47.4, P < .001), PCS (40.7 vs 38.5, P < .001), and postoperative PCS scores (48.9 vs 46.7, P < .001). There was no difference in mean PCS improvement (8.1 vs 8.2; P = .798) or clinically significant PCS change (P = .963). DAA was associated with shorter LOS by 0.49 days (95% confidence interval [CI] = 0.32-0.65, P < .001), lower odds of extended LOS (odds ratio = 0.33, 95% CI = 0.21-0.50, P < .001), and lower odds of facility discharge (odds ratio = 0.54, 95% CI = 0.37-0.79, P < .001). No difference in operative time (86 vs 87 minutes; P = .812) or 90-day reoperations (1 vs 1%; P = .347) was observed.

Conclusion

DAA patients presented with higher preoperative PCS and MCS scores, yet both groups experienced significant improvement. DAA was associated with decreased LOS and lower odds of extended LOS and facility discharge. There was no difference in operative time or reoperation.

Bipolar hemiarthroplasty for the treatment of femoral neck fractures with minimally invasive anterior approach in elderly

OBJECTIVES

The purpose of the study was to evaluate the efficacy of hemiarthroplasty with minimally invasive direct anterior approach (DAA) for the treatment of femoral neck fracture in elderly patients. We aimed to compare the DAA and the standard anterolateral approach (ALA), assessing multiple peri‑ and post-operative parameters.

DESIGN AND SETTING

Between December of 2015 and May of 2017, patients operated with medial femoral neck fractures using bipolar hemiarthroplasty with DAA or ALA were evaluated. The volume of bleeding and transfusion, postoperative level of pain, mobilisation and functional outcome were assessed retrospectively.

PARTICIPANTS

Patients between the age of 75 and 85, suffering Garden Type III Pauwels Type III and Garden Type IV medial femoral neck fractures were entered to the study. Patients had no history of anticoagulant therapy; the operation was performed in the first 48 h. All patients received similar postoperative pain management and physiotherapy. The type of implants was determined by the patients' bone morphology and quality.

MAIN OUTCOME MEASURES

The outcomes of interest were the level of postoperative pain, blood loss, rate of recovery and physiotherapy, altered gait pattern and accuracy of leg length, related to DAA and ALA techniques.

RESULTS

The 51 patients operated with DAA showed significantly less pain, based on VAS (visual analogue scale), starting of the first postoperative day. Those patients who were subjected to DAA met with the criteria of hospital discharge 1.68 days earlier, compared to ALA patients. The length of leg was accurately set in 21% of ALA vs 54.9% of DAA patients. On the 12th week follow-up, limping was detected only 5.9% of DAA vs 46% of ALA groups. On the postoperative 2nd and 6th weeks, the HHS (Harris Hip Score) was significantly better in patients with DAA, compared to ALA (77 vs 65 and 91 vs 77, p < .05).

CONCLUSION

The bipolar hemiarthroplasty with DAA allows earlier mobilisation, reduced postoperative pain and need for rehabilitation with an overall better functional outcome, compared to ALA. DAA is proven a reliable choice for femoral neck fractures, offering good outcome and faster recovery, similarly to total hip arthroplasties with degenerative arthritis.

Does Structured Postgraduate Training Affect the Learning Curve in Direct Anterior Total Hip Arthroplasty? A Single Surgeon's First 200 Cases

Background

The direct anterior approach (DAA) used for primary total hip arthroplasty has been shown to improve early postoperative outcomes, but prior studies have identified a marked learning curve for surgeons transitioning to this approach. However, these studies do not capture surgeons with postgraduate fellowship training in DAA. Therefore, the purpose of this study was to evaluate the learning curve by comparing perioperative outcomes for the first 100 to latter 100 cases and first 50 to final 50 cases.

Methods

The first 200 consecutive primary total hip arthroplasties performed by a single surgeon were prospectively followed up for up to 2 years postoperatively. Data on demographic and perioperative factors, 90-day readmissions, and short- and long-term complications were collected. Radiographic outcomes included acetabular cup anteversion and abduction measurements. Logistic regressions were used to calculate odds ratios and confidence intervals for surgical time greater than 2 hours.

Results

The first 100 and second 100 cases had significant differences in operative times (118.1 vs 110.4 minutes, P = .009), acetabular abduction (38.3 vs 35.5 degrees, P = .001) and anteversion (13.5 vs 15.1 degrees, P = .009), and incidence of neuropraxia (41 vs 9%, P < .001). Estimated blood loss, transfusions, discharge disposition, length of stay, readmission, and other complications had no statistical significance between the first and second 100 cases. The first 50 cases had higher odds of surgical time greater than 2 hours (odds ratio = 5.2, 95% confidence interval = 1.84-14.75, P = .002) than the final 50 cases.

Conclusions

When compared with the existing literature, incorporation of DAA into fellowship training can lead to reduction in fractures and reoperation rates.

Radiographic factors to predict operation time of direct anterior total hip arthroplasty for dysplastic hips

BACKGROUND

This study aimed to identify radiographic factors that could predict surgical difficulty in direct anterior total hip arthroplasty (THA) for dysplastic hips.

PATIENTS AND METHODS

The clinical records of 160 patients (204 hips) who underwent primary THA for the treatment of developmental dysplasia of the hip were retrospectively investigated. All THAs were performed through a direct anterior approach by a single surgeon. A multiple regression analysis was developed to identify the independent predictor of operation time, including variables such as age, sex, height, body mass index (BMI), the use of bone cement, previous hip surgery, and radiographic references, including the pelvic horizontal to vertical ratio, the extent of proximal and horizontal migration of the femoral head, flatness of the femoral head, and the vertical distance between the tips of the greater trochanter and the femoral head.

RESULTS

A multiple regression analysis revealed that as radiographic factors, proximal migration of the femoral head, and lower position of the femoral head related to the greater trochanter were significantly associated with longer operation time. In addition, our results revealed that younger age, male sex, height, high BMI, cement use, and previous hip surgery were also significantly associated with longer operation time.

CONCLUSIONS

Our findings indicate that proximal migration of the femoral head and high-riding greater trochanter are isolated radiographic predictors of the longer operation time of direct anterior THA for dysplastic hips.

Early Experience of Direct Anterior Approach Total Hip Arthroplasty: Analysis of the First 53 Cases

Purpose

To determine if it is feasible and safe for a surgeon to transition from using the posterolateral approach to direct anterior approach (DAA) by evaluating the first 53 cases of total hip arthroplasty using a DAA.

Materials and Methods

A retrospective review of 52 patients who underwent THA using a DAA between July 2017 and December 2018. Reasons for THA were: femoral neck fracture (n=34), avascular necrosis (n=13), and arthritis (n=6). The mean age was 70 years old. An assessment of feasibility was made by analyzing mean operative time and blood loss. Cup inclination, anteversion, and leg length discrepancy (LLD) were measured using postoperative radiology. Safety of the DAA was judged using the incidence and nature of all complications.

Results

The mean operative time was 112 minutes. 135 minutes for the 1st 10 cases, 100 minutes for 2nd 10 cases, 113 minutes for 3rd 10 cases, 119 minutes for 4th 10 cases, and 91 minutes for the final 13 cases. The mean blood loss was 724 mL. Average cup inclination was 40.27°; 2 cases were out of safety angle. Mean anteversion was 16.18°. No intraoperative fractures or infections were observed. LLD was detected in 3 cases, one of which underwent revision due to walking difficulty. Dislocation occurred in 3 cases, all within the first 20 cases, however, there was no recurrent dislocation.

Conclusion

DAA for THA was deemed to be feasible and safe based on an assessment of operative time, blood loss and complications.

A Comparison of the Incidences of Venous Thromboembolism after Total Hip Arthroplasty between the Direct Anterior Approach and the Direct Lateral Approach, Especially in the Early Period after Introduction of the Direct Anterior Approach

OBJECTIVE

To compare the incidence of venous thromboembolism (VTE) after total hip arthroplasty (THA) using the direct anterior approach (DAA) with that using the direct lateral approach (DLA). In addition, patient background characteristics and the incidence of VTE were compared between the first half and the latter half of the period after introducing DAA and against DLA.

METHOD

This was a retrospective, multicenter study involving 109 patients (116 hips) who had undergone primary unilateral THA. Thirty-six hips underwent THA using DAA and 80 hips underwent THA using DLA. Patient information including sex, age, and preoperative diagnosis was collected. The incidence of VTE was compared between DAA and DLA. Moreover, the patients who underwent THA using DAA were divided into 2 groups (first half and latter half groups), and sex, age, body mass index (BMI), and surgical time were compared between the 2 groups. Moreover, the incidence of VTE was compared among the 3 groups (first half of DAA, latter half of DAA, and DLA).

RESULTS

The incidence of VTE in the DAA group was significantly higher than that in the DLA group (p=0.014). The incidence of VTE in the first half group was significantly higher than in the latter half group and the DLA group (p=0.035 and p=0.001, respectively), and there was no difference in the incidence of VTE between the latter half group and the DLA group (p=0.923). Surgical time was significantly longer in the first half group than in the latter half group (p=0.046).

CONCLUSIONS

In the first half of the period after introducing the DAA, more VTEs occurred than in the DLA. It may be important to shorten the surgical time in the early stage of introducing the DAA, and aggressive anticoagulation therapy may be required until the surgeon becomes familiar with the procedure.

Ten-Year Experience With the Anterior Approach to Total Hip Arthroplasty at a Tertiary Care Center

BACKGROUND

The anterior approach (AA) to total hip arthroplasty (THA) has advantages for patients and healthcare providers. However, some studies have reported high rates of adverse events when introducing AA-THA. This was not consistent with our center's experience, where 4 senior surgeons safely introduced AA-THA into practice. The purpose of this study is to define the adverse event rates associated with the introduction of AA-THA by a group of experienced surgeons at a single tertiary care center and define experiential factors that may modify adverse event rates.

METHODS

Retrospective review of prospectively collected data for an observational cohort of all patients undergoing a THA between 2006 and 2017 was conducted. Four senior surgeons at a single institution operated on 1087 primary elective hips using AA-THA.

RESULTS

Between 2006 and 2016, AA-THA rose from 1.5% to 53.2% of annual THA. Adverse events included intraoperative events, early postoperative periprosthetic fractures, dislocation, implant failure, early infection, and wound complications. We observed an overall 90-day adverse event rate of 6.4% (of 1087 hips). The adverse event rate was 41.6% (of 12 hips) in the first 12 months of the study period and 3.6% (of 166 hips) in the final 12 months of the study period reviewed. Sixty hips (5.5%) required a reoperation with or without revision of components, 1 (8.3%) in the first 12 months of the study period and 1 (0.6%) in the final 12 months of the study period. Infection and wound complications were the most common causes of reoperation at 1.8% for all cases (20 hips). Higher rates of adverse events are associated with early procedures (n ≤ 15) for all surgeons but showed no statistically significant impact on 5-year survival rate.

CONCLUSION

Our experience demonstrates that AA-THA can be introduced into practice with an acceptable adverse event rate when compared with other approaches to THA. As expected the incidence of adverse events is higher in the early part of the learning curve. Surgeon mentoring in the first 20 cases should be considered to minimize risk of adverse events.

LEVEL OF EVIDENCE

Therapeutic Level III.

['Hip-in-a-Day']

BACKGROUND

In 2017, the average length of stay for primary hip replacement patients in Germany was 10.2 days. In our hospital, we have been able to reduce the length of stay in the last 10 years to an average of 3.8 days.

OBJECTIVES

Since September 2015, we offer the 'Hip-in-a-Day' program. This ultra-fast-track pathway consists of a hip arthroplasty procedure with the same day discharge of a well-prepared and explicitly selected patient with maximum intensive interdisciplinary care. The aim is to present the philosophy, treatment principles and daily routine during the pre-, intra- and postoperative phase. The challenges in the German health care system will be discussed.

MATERIAL AND METHODS

From September 2015 to November 2019, we operated on 97 patients (50 F: 47 M, ages: 43-77 years, ⌀ 55 years) who had undergone the Hip-in-a-Day pathway. All 97 patients received general anesthesia. Surgery was performed via the direct anterior approach (DAA) to the hip. Patients stayed in the day clinic less than 24 h after surgery. Of these, 30 patients were discharged on the day of surgery (⌀ 12 h stay), and 67 patients left the clinic the day after the operation (⌀ 20 h stay). Due to integrated health-care contracts with health-care providers, we were eligible to receive bundled reimbursement for this patient population.

RESULTS

All 97 patients completed the Ultra-Fast-Track pathway and were able to meet the discharge criteria within 24 h after surgery. 96 of the 97 (98.9%) patients were able to complete Hip-in-a-Day without readmission. One patient had to undergo revision surgery after 10 days due to cup loosening. All patients (100%) were very satisfied with the routine of the day and the fast discharge from the hospital.

CONCLUSION

The aim of Hip-in-a-Day is to discharge patients within 24 h after surgery. The implementation of the setup at the day clinic is intensive interdisciplinary care of all participating departments, as well as the three cornerstones of anesthesiological management, minimally invasive surgical techniques and patient compliance. In our clinic, ultra-fast-track arthroplasty is routinely feasible and has produced great patient satisfaction. Statutory health-care providers should include short-stay hip arthroplasty into the DRG system, so that this care concept can be reimbursed and practiced nationwide in Germany.

Acetabular revision using a Kerboull-type reinforcement device through direct anterior approach

BACKGROUND

The direct anterior approach has gained popularity in total hip arthroplasty (THA) over the past decade. However, there are few reports that describe the use of this approach for cases of complex revision. The purpose of this study was to report the surgical procedure and early clinical results of acetabular revision in the presence of bone defects using a Kerboull-type reinforcement device through the direct anterior approach.

METHODS

Eleven patients who had undergone acetabular reconstruction using a Kerboull-type reinforcement device for aseptic or septic loosening bone defects were enrolled. All procedures were performed using the direct anterior approach on a standard operating table. The mean age was 71.8 years, the mean period from initial surgery to revision THA was 14.5 years, and the mean follow-up period was 19.8 months.

RESULTS

The Kerboull-type acetabular reinforcement device with cemented cup combined with allogenic femoral head bone grafts was used in all hips. The mean operative time and intraoperative blood loss were 148 min and 743 g, respectively. None of the patients required allogeneic blood transfusion. One patient required revision surgery 11 months postoperatively because of device displacement. No other major or minor orthopedic complications were observed.

CONCLUSION

The direct anterior approach allows for less invasive acetabular reconstruction using a Kerboull-type reinforcement device.

ALDI (Anterior Lateral Decubitus Intermuscular) approach to the hip: Comprehensive description of the surgical technique with operative video

The direct anterior approach to the hip is judged to be difficult and even after many solutions, such as special operating tables, have been proposed to perform it, in some reports the complication rate remains high. The complications reported are nerve lesions, dislocation, muscles damages, intraoperative fractures. We describe a modification of the anterior approach, undertaken keeping the patient in lateral decubitus, in order to gain a better range of leg movement and a significant reduction of the force applied to the retractors, the technique was named ALDI (anterior lateral decubitus intermuscular) approach. The surgeon starts behind the patient as in all the other traditional approaches, to maintain unchanged the acetabular view and the dexterity in cup implantation. For the femoral preparation, he moves in front of the patient to have a better visualization. In a series of 150 patients, with a mean operative time of 51.38minutes (range, 40-112), we had no intraoperative fractures, one (0.6%) lateral femoral cutaneous nerve temporary neurapraxia, one (0.8%) posttraumatic dislocation four years after the operation and, no revisions for aseptic loosening or infection. At the 5 years follow-up, the mean Oxford Hip score was 45.2 (range, 38-48; SD 2.6), the mean Harris Hip Score was 96,7 (range, 76-100; SD 2.8), and the mean UCLA score was 7 (range, 5-10; SD 1.4). The possibility to always obtain the optimal position of the surgical window with reduced tension on the muscles, and the unchanged initial surgeon position, could make the ALDI approach the ideal technique for the surgeons that decide to perform an anterior approach.

Surgical approach significantly affects the complication rates associated with total hip arthroplasty

AIMS

A variety of surgical approaches are used for total hip arthroplasty (THA), all with reported advantages and disadvantages. A number of common complications can occur following THA regardless of the approach used. The purpose of this study was to compare five commonly used surgical approaches with respect to the incidence of surgery-related complications.

PATIENTS AND METHODS

The electronic medical records of all patients who underwent primary elective THA at a single large-volume arthroplasty centre, between 2011 and 2016, with at least two years of follow-up, were reviewed. After exclusion, 3574 consecutive patients were included in the study. There were 1571 men (44.0%) and 2003 women (56.0%). Their mean age and body mass index (BMI) was 63.0 years (sd 11.8) and 29.1 kg/m² (sd 6.1), respectively. Data gathered included the age of the patient, BMI, the American Society of Anesthesiologists (ASA) score, estimated blood loss (EBL), length of stay (LOS), operating time, the presence of intra- or postoperative complications, type of complication, and the surgical approach. The approaches used during the study were posterior, anterior, direct lateral, anterolateral, and the northern approach. The complications that were recorded included prolonged wound drainage without infection, superficial infection, deep infection, dislocation, aseptic loosening, and periprosthetic fracture. Finally, the need for re-operation was recorded. Means were compared using analysis of variance (ANOVA) and Student's t-tests where appropriate and proportions were compared using the chi-squared test.

RESULTS

A total of 248 patients had 263 complications related to the surgery, with an incidence of 6.94%. The anterior approach had the highest incidence of complications (8.5% (113/1329)) and the posterior approach had the lowest, at 5.85% (97/1657; p = 0.006). Most complications were due to deep infection (22.8%), periprosthetic fracture (22.4%), and prolonged wound drainage (21.3%). The rate of dislocation was 0.84% (14/1657) with the posterior approach and 1.28% (17/1329) with the anterior approach (p = 0.32).

CONCLUSION

Overall, THA has a relatively low complication rate. However, the surgical approach plays a role in the incidence of complications. We found that the posterior approach had a significantly lower overall complication rate compared with the anterior approach, with an equal dislocation rate. Periprosthetic fracture and surgical site infection contributed most to the early complication rates. Cite this article: Bone Joint J 2019;101-B:646-651.

Do Postoperative Results Differ in a Randomized Trial Between a Direct Anterior and a Direct Lateral Approach in THA?

BACKGROUND

The direct lateral approach to THA provides good exposure and is associated with a low risk of dislocations, but can result in damage to the abductor muscles. The direct anterior approach does not incise muscle, and so recovery after surgery may be faster, but it has been associated with complications (including fractures and nerve injuries), and it involves a learning curve for surgeons who are unfamiliar with it. Few randomized trials have compared these approaches with respect to objective endpoints as well as validated outcome scores.

QUESTIONS/PURPOSES

The purpose of this study was to compare the direct anterior approach with the direct lateral approach to THA with respect to (1) patient-reported and validated outcomes scores; (2) frequency and persistence of abductor weakness, as demonstrated by the Trendelenburg test; and (3) major complications such as infection, dislocation, reoperation, or neurovascular injury.

METHODS

We performed a randomized controlled trial recruiting patients from January 2012 to June 2013. One hundred sixty-four patients with end-stage osteoarthritis were included and randomized to either the direct anterior or direct lateral approach. Before surgery and at 3, 6, 12, and 24 months, a physiotherapist recorded the Harris hip score (HHS), 6-minute walk distance (6MWD), and performed the Trendelenburg test directly after the 6MWD. The patients completed the Oxford Hip Score (OHS) and the EQ-5D. The groups were not different at baseline with respect to demographic data and preoperative scores. Both groups received the same pre- and postoperative regimes. Assessors were blinded to the approach used. One hundred fifty-four patients (94%) completed the 2-year followup; five patients from each group were lost to followup.

RESULTS

There were few statistical differences and no clinically important differences in terms of validated or patient-reported outcomes scores (including the HHS, 6MWD, OHS, or EQ-5D) between the direct anterior and the lateral approach at any time point. A higher proportion of patients had a persistently positive Trendelenburg test 24 months after surgery in the lateral approach than the direct anterior approach (16% [12 of 75] versus 1% [one of 79]; odds ratio, 15; p = 0.001). Irrespective of approach, those with a positive Trendelenburg test had statistically and clinically important worse HHS, OHS, and EQ-5D scores than those with a negative Trendelenburg test. There were four major nerve injuries in the direct anterior group (three transient femoral nerve injuries, resolved by 3 months after surgery, and one tibial nerve injury with symptoms that persist 24 months after surgery) and none in the lateral approach.

CONCLUSIONS

Based on our findings, no case for superiority of one approach over the other can be made, except for the reduction in postoperative Trendelenburg test-positive patients using the direct anterior approach compared with when using the direct lateral approach. Irrespective of approach, patients with a positive Trendelenburg test had clinically worse scores than those with a negative test, indicating the importance of ensuring good abductor function when performing THA. The direct anterior approach was associated with nerve injuries that were not seen in the group treated with the lateral approach.

LEVEL OF EVIDENCE

Level I, therapeutic study.

Direct Anterior Approach Total Hip Arthroplasty: An Adjunct to an Enhanced Recovery Pathway: Outcomes and Learning Curve Effects in Surgeons Transitioning From Other Surgical Approaches

BACKGROUND

The aim of this study was to investigate whether the direct anterior approach (DAA) to total hip arthroplasty (THA) resulted in a shorter length of stay (LOS) in surgeons new to the approach when compared to their previously used approach. Perioperative complications were also assessed.

METHODS

We examined 93 DAA THA performed by 3 hip arthroplasty surgeons at a single institution comparing these to their previous 166 operations performed using the lateral or posterior approach.

RESULTS

Fixed-effects generalized linear modeling demonstrated that patients who underwent THA by the DAA had 26% shorter LOS than those who were operated on using lateral or posterior approaches (adjusted risk ratio = 0.74; 95% confidence interval = 0.65-0.84; P < .001). A greater proportion of DAA patients were discharged directly home (98% vs 87%, F (1,233) = 8.12, P = .005) and complication rates were comparable between groups.

CONCLUSION

The DAA can reduce patient LOS and may be a valuable addition to enhanced recovery pathways. Our findings also suggest that surgeons transitioning to the DAA do not have an increased complication rate when compared to their previous approach.

In-hospital outcomes with anterior versus posterior approaches in total hip arthroplasty: meta-analysis of randomized controlled trials

PURPOSE

The purpose of this study was to determine whether in-hospital outcomes are different with anterior approach (AA) or posterior approach (PA) in primary total hip arthroplasty (THA).

METHODS

We performed a systematic review with random-effects meta-analysis of random-ized controlled trials (RCTs) comparing AA with PA in primary THA. Hospital outcomes were reported as odds ratio (OR), weight mean difference, or standardized mean difference (SMD).

RESULTS

A total of seven RCTs with 609 patients were included. Outcomes favoring AA included 1.4 cm shorter incision (p=0.045), 0.5 days shorter hospital stay (p=0.01), 0.5 points less pain on a 0-10 scale (p=0.007), and less opioid use (SMD=-0.39 corresponding to 12 fewer morphine equivalents per day, p=0.01). The procedure time was 16 minutes longer with AA vs. PA (p=0.002). There were no statistical differences between AA and PA in operative blood loss (mean difference =19 mL, p=0.71), transfusions (9.7% vs. 16.2%, OR=0.45, p=0.39), or complications (5.5% vs. 4.1%, OR=1.42, p=0.62).

CONCLUSION

While the AA to primary THA may take longer time compared with the PA, the incision is shorter, and patients report slightly less pain, require less opioid medication, and leave the hospital earlier. The clinical relevance of these differences during longer-term follow-up is uncertain. The choice of surgical approach in primary THA should also consider factors such as experience of the surgeon and preferences of the surgeon and patient.

Similar Superior Patient-Reported Outcome Measures for Anterior and Posterolateral Approaches After Total Hip Arthroplasty: Postoperative Patient-Reported Outcome Measure Improvement After 3 months in 12,774 Primary Total Hip Arthroplasties Using the Anterior, Anterolateral, Straight Lateral, or Posterolateral Approach

BACKGROUND

Patient-reported outcome measures (PROMs) are used to evaluate the outcome of total hip arthroplasty (THA). We determined the effect of surgical approach on PROMs after primary THA.

METHODS

All primary THAs, with registered preoperative and 3 months postoperative PROMs were selected from the Dutch Arthroplasty Register. Based on surgical approach, 4 groups were discerned: (direct) anterior, anterolateral, direct lateral, and posterolateral approaches. The following PROMs were recorded: Hip disability and Osteoarthritis Outcome Score Physical function Short form (HOOS-PS); Oxford Hip Score; EQ-5D index score; EQ-5D thermometer; and Numeric Rating Scale measuring pain, both active and in rest. The difference between preoperative and postoperative scores was calculated (delta-PROM) and used as primary outcome measure. Multivariable linear regression analysis was performed for comparisons. Cohen's d was calculated as measure of effect size.

RESULTS

All examined 4 approaches resulted in a significant increase of PROMs after primary THA in the Netherlands (n = 12,274). The anterior and posterolateral approaches were associated with significantly more improvement in HOOS-PS scores compared with the anterolateral and direct lateral approaches. Furthermore, the posterolateral and anterior approaches showed greater improvement on Numeric Rating Scale pain scores compared with the anterolateral approach. No relevant differences in delta-PROM were seen between the anterior and posterolateral surgical approaches.

CONCLUSION

Anterior and posterolateral surgical approaches showed more improvement in self-reported physical functioning (HOOS-PS) compared with anterolateral and direct lateral approaches in patients receiving a primary THA. However, clinical differences were only small.

The direct anterior minimal invasive approach in total hip replacement: a prospective departmental study on the learning curve

INTRODUCTION

Introduction of new surgical techniques is normal, but seldom monitored in real time. The purpose of this study was to monitor the learning curve when introducing a new surgical technique to a department. We did a prospective evaluation of the learning curve when introducing the minimally invasive direct anterior approach in total hip arthroplasty. We wish to investigate whether there is a learning curve for the direct anterior minimal invasive approach in total hip replacement and what are the early complications to this approach.

METHODS

The department changed from the direct lateral approach to the minimally invasive direct anterior approach. We monitored the first 522 patients operated using this approach with regards to patient outcome scores and complications 6 months postoperatively.

RESULTS

The last 250 patients operated all had significantly better results with regard to patient outcome scores and cup placement. We investigated 100 patients at a time and compared them with the rest of the patient and found the same pattern. This pattern ends when we reach patients somewhere between 200-300.

DISCUSSIONS

We established the learning curve on a departmental level with regards to introduction of the minimal invasive direct anterior approach. We see a steady improvement in scores with regards to patient outcome scores and cup positioning until we reach a steady-state. The learning curve here flattens out. Departments must understand that one should expect early complications and somewhat less than optimal results at first when introducing this new surgical technique.

Cementless Tapered-Wedge Stem Length Affects the Risk of Periprosthetic Femoral Fractures in Direct Anterior Total Hip Arthroplasty

BACKGROUND

Although the popularity of the direct anterior approach for total hip arthroplasty has increased, the femoral procedure in this approach is considered technically challenging, and one of the most frequent complications reported was periprosthetic femoral fractures. The present study aimed to identify factors for predicting the risk of periprosthetic femoral fractures after using stems with a cementless tapered-wedge design through the direct anterior approach.

METHODS

We retrospectively assessed the medical records of 686 patients (851 hips) who underwent primary total hip arthroplasty using a single stem with a cementless tapered-wedge design having a short or standard length option. The direct anterior approach on a standard operating table was used for all hips. Multivariate logistic regression analysis was performed to identify the independent predictors of intraoperative and early postoperative periprosthetic fractures.

RESULTS

Seventeen periprosthetic femoral fractures (2.0%) were observed, including 10 intraoperative (1.2%) and 7 postoperative (0.8%) fractures. The occurrence rate of fractures using short stems was significantly higher compared with that using standard stems. The multivariate logistic regression analysis revealed that only stem length was significantly associated with periprosthetic fractures.

CONCLUSION

Our results indicate that the stem design affects the risk of periprosthetic femoral fractures.

[Mid-term effectiveness of total hip arthroplasty by direct anterior approach]

Objective

To retrospectively compare the mid-term effectiveness between by direct anterior approach (DAA) and by posterolateral approach in total hip arthroplasty (THA).

Methods

Between January 2009 and December 2010, 110 patients (110 hips) treated with THA and followed up more than 5 years were chosen in the study. THA was performed on 55 patients by DAA (DAA group), and on 55 patients by posterolateral approach (PL group). There was no significant difference in gender, age, body mass index, types of hip joint disease, and preoperative Harris score between 2 groups ( P>0.05). The operation time, amount of bleeding, length of hospital stay, postoperative complications, and the Harris scores were recorded and compared.

Results

There was no significant difference in operation time and length of hospital stay between 2 groups ( t=0.145， P=0.876; t=1.305, P=0.093). The amount of bleeding was significantly less in DAA group than in PL group ( t=2.314, P=0.032). All patients were followed up 5-7 years (mean, 5.97 years). Complications happened in 5 cases (9.1%) of DAA group and in 3 cases (5.5%) of PL group, and there was no significant difference in the incidence of complications between 2 groups ( χ²=0.539， P=0.463). There was significant difference in Harris scores at 6 months after operation between 2 groups ( t=2.296, P=0.014), but no significant difference was found in Harris score at 1 year and 5 years between 2 groups ( t=1.375, P=0.130; t=0.905, P=0.087). Further analysis, at 6 months after operation, the joint function score in DAA group was significantly higher than that in PL group ( t=1.087, P=0.034), while there was no significant difference in the pain score and range of motion score between 2 groups ( t=1.872, P=0.760; t=1.059, P=0.091).

Conclusion

THA by DAA has the advantages of less bleeding and faster recovery. The short-term effectiveness is superior to the THA by traditional posterolateral approach, but there is no obvious advantage in the mid-term effectiveness.

Influence of Surgical Approach on Pelvic Lift in Hip Arthroplasty During Cup Insertion

The position of the acetabular cup is a major factor in the long-term outcome of total hip arthroplasty (THA). Malpositioning of the acetabular cup frequently has been reported with the use of a minimally invasive implantation technique. It remains unclear whether the limited visibility or the increased retractor traction and thus tilting of the pelvis during cup implantation is the cause. This study investigated the influence of iatrogenically related pelvic lift using an anterolateral minimally invasive THA technique. In a group of 30 consecutive patients who underwent THA via a minimally invasive anterolateral approach, iatrogenic lifting of the pelvis was measured with a smartphone using a 3-axis accelerometer and compared with patients in a historical age- and sex-matched control group who underwent THA using a transgluteal approach. Postoperatively, the inclination and anteversion of the cup was determined on pelvic radiographs. In the anterolateral group, the pelvis was lifted by a maximum of 6.3° and by an average of 3.9° when the acetabular cup was impacted; no difference was noted compared with the transgluteal group. In contrast, the cups in the anterolateral group showed significantly increased inclination and reduced anteversion. In both techniques, the iatrogenic tilting of the pelvis at the time of cup implantation occurred to a comparable extent. Therefore, the significant differences in postoperative radiographs cannot be attributed to increased retractor traction on exposure of the acetabulum, which means that the limited visibility must be responsible. [Orthopedics. 2017; 40(4):e589-e593.].