How do dislocation rates differ between different approaches to total hip arthroplasty? A systematic review and meta-analysis

Abstract

Background: Different surgical approaches for total hip arthroplasty (THA) exist, without predisposition when it comes to dislocation risk. The direct anterior approach (DAA) is thought to have reduced risk since soft tissue trauma is minimalized. Therefore, we assessed the dislocation risk for different surgical approaches, and the relative dislocation risk of DAA compared to other approaches. Methods: Six electronic databases were systematically searched for prospective studies reporting dislocation following THA. Proportion meta-analyses were performed to assess the dislocation rate for subgroups of the surgical approach. Meta-analysis for binary outcomes was performed to determine the relative risk of dislocation for the DAA compared to other approaches. Results: Eleven studies with 2025 patients were included (mean age 64.6 years, 44% male, mean follow-up 10.5 months), of which four studies were also used in the risk ratio meta-analysis. Overall dislocation rate was 0.79% (95% CI 0.37–1.69). Subgroup analyses showed that most dislocations occurred in the posterior approaches group (1.38%), however non-significant. Furthermore, the DAA emerged with a non-significant lower risk of dislocation (RR 0.37, 95% CI 0.05–2.46) compared to other surgical approaches. Conclusion: Current literature shows non-significant predisposition for a surgical approach to THA regarding dislocation risk. To what extent patient characteristics influence the risk of dislocation could not be determined. Future research should focus on this, as well as on the influence of a surgeon's experience with a specific approach.

Keywords

Hip prosthesis joint dislocation risk surgical approach

Introduction

Total hip arthroplasty (THA) is one of the most common and successful orthopedic operations for the treatment of hip disease. It can significantly eliminate hip pain, restore hip function and substantially improve quality of life.¹ The main clinical indications to perform a THA are pain and a reduced range of motion of the hip joint. Patients with osteoarthritis (OA) comprise 87% of all indications for THA.²

As for all surgical procedures, THA presents a risk of complications such as infection, aseptic loosening, Trendelenburg gait, leg length discrepancy, periprosthetic fractures, or dislocation of the joint. The risk of dislocation is the highest in the first few months after surgery.³ In primary THA, the incidence of joint dislocation ranges between 0.3% and 10%, but in revision THA this can even go up to 28%.³ Most dislocations are isolated events and can be treated non-operatively; however, some cases will require hip revision surgery to prevent recurrent dislocations and are performed in approximately one-third of the patients after dislocation following THA.⁴

There are different surgical approaches for THA, without a particular predisposition given the current literature.^5,6 Although the posterolateral approach is still the most frequently used approach, the direct anterior approach (DAA) is gaining popularity.⁷ In the DAA, the hip joint is replaced with reduced soft tissue trauma, theoretically reducing the risk of dislocation.^8,9 Alternatively, the supine positioning may allow for better cup inclination and anteversion.^10,11 In the literature, however, there is no consensus on which surgical approach has the lowest risk of dislocation. Throughout the literature, both a lower^12,13 and higher^14,15 dislocation rate have been reported for the DAA compared to other approaches. However, regardless of the surgical approach that is used, the incidence of dislocation was low in these studies.^12,14,15 Given the inconsistent results regarding dislocation rates, aggregated evidence is desired. Therefore, we performed a systematic review with meta-analysis to assess (a) the risk of dislocation for different surgical approaches and (b) the relative risk of dislocation of the DAA compared to other surgical approaches, for patients after THA.

Materials and methods

This study was conducted using methods from the Cochrane Handbook¹⁶ and in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) 2020 statement.¹⁷ The study protocol was registered on PROSPERO (registration ID: CRD42019121619).

Search strategy

Six electronic databases (PubMed, Embase, Central, Cochrane Library, PEDro, and Trip) were searched on 11 January 2022. The search strategy (Appendix 1) was developed in consultation with an information specialist and combined search terms for three major themes: ‘total hip arthroplasty’, ‘dislocation’, and ‘approach’. Key terms were mapped to controlled headings and expanded to include free-text terms, as appropriate for the specific database. Since we aimed to observe the modern DAA technique and current component sizes, the search was limited to studies published since 2009. Grey literature was also assessed through Greylit and OpenGrey. After the removal of duplicates, three reviewers (MK, AL and JB) independently reviewed all studies on title/abstract and subsequently reviewed eligible studies in full text using RAYYAN.¹⁸ Furthermore, references of included studies were manually searched for additional studies. Disagreement on eligibility was resolved amongst the reviewers and consensus was reached on the inclusion and exclusion of all studies.

Study selection

A study was included if it (a) was a randomized controlled trial (RCT) or prospective observational study, (b) included adult participants undergoing primary THA because of osteoarthritis, (c) reported data on dislocation, and (d) – in case of an RCT – compared DAA with another approach. Studies were excluded if they (a) were retrospective or (b) included patients with other operation indications than osteoarthritis. Furthermore, only studies written in English, German, French, Spanish, and Dutch were included.

Methodological quality

Methodological quality of the included studies was independently graded with the Cochrane risk of bias (RoB) 2.0 tool¹⁹ for RCTs and with the Methodological Index for Non-Randomized Studies (MINORS) criteria²⁰ for the prospective observational studies. The level of evidence was determined using the Grades of Recommendation Assessment, Development and Evaluation (GRADE) approach.²¹

Data extraction

All data were collected in Excel 365 (Microsoft Corp., Redmond, USA). From each study, we extracted the following information: first author, publication year, country, study design, number of patients (per group), sample characteristics, surgical approach, and follow-up length. Then, we extracted the main clinical outcome and the number of dislocations.

Statistical analysis

Statistical analysis was performed using the ‘meta’ package in R version 1.4.1717 (R Foundation for Statistical Computing, Vienna, Austria). First, we calculated the overall mean dislocation rate using a single proportion meta-analysis. Subgroup analyses were performed based on the surgical approach. Then, the relative risk (RR) of dislocation for the DAA compared to other surgical approaches was calculated by means of meta-analysis for binary outcome data. Random-effect models were used. All tests were two-sided, and significance was attributed to a p-value of <0.05. Results of the meta-analyses are presented in forest plots. Finally, a funnel plot was created to visually assess for publication bias.

Results

Study selection and characteristics

The initial search yielded 868 records. After removal of duplicate studies, 703 studies remained. Another 594 studies were excluded based on their titles and abstracts, 11 reports could not be retrieved, thus 98 studies were read in full. Subsequently, 87 were excluded because they failed to meet the inclusion criteria. In the end, 11 studies were included in this systematic review and meta-analysis: eight RCTs and three prospective observational studies. Details of the study selection are presented in Figure 1.

Figure 1.

PRISMA flowchart of study selection.

There were no indications for publication bias, as can be observed in the funnel plot (Figure 2).

Figure 2.

Funnel plot of included studies.

The included studies included a total of 2025 patients, involving 1306 in the posterior subgroup (respectively presented as 189 posterior (PA), 917 posterolateral (PLA), and 200 direct superior (DSA)), 476 direct anterior (DAA), and 243 direct lateral (LA; Table 1). Four of the eight RCTs were considered as prospective observational because the contrast within the study was not the surgical approach. For these studies,^10,22–29 subgroups of patients were merged to conduct the appropriate meta-analysis. Accordingly, all studies were included in the meta-analysis to determine overall mean dislocation, whereas only four RCTs^30–33 were analyzed to determine the RR of DAA compared to other approaches.

Table 1.

Study and participant characteristics of included studies.

Study	Design	Sample size (Pts/Hips), n	Indication	Gender (M/F), n	Age (y), mean	Surgical approach	Follow-up
Barrett, 2013, United States³⁰	RCT	87/87	Non-inflammatory degenerative joint disease	48/39	62.3	DAA n = 43 PLA n = 44	1 year
Cheng, 2017, Australia³¹	RCT	73/73	Unilateral symptomatic OA	33/40	60.9	DAA n = 35 PA n = 38	3 months
Edipoglu, 2021, Turkey²⁹	RCT; considered as prospective cohort	42/42	Primary OA	20/22	62.4	PA	6 months
Mjaaland, 2019, Norway³²	RCT	164/164	OA	55/109	66.5	DAA n = 84 DLA n = 80	> 1 year
Peters, 2019, The Netherlands²⁴	RCT; considered as prospective cohort	408/408	OA	175/233	64.4	PLA n = 408	2 months
Rodriguez, 2014, United States²⁸	CCT; considered as prospective cohort	120/120	Unilateral OA	54/66	59.5	DAA n = 60 PA n = 60	1 year
Spaans, 2015, The Netherlands³⁴	CCT; considered as prospective cohort	465/465	Primary OA	163/302	69.9	PLA n = 465	1 year
Taheriazam, 2017, Iran²⁵	RCT; considered as prospective cohort	180/180	Bilateral OA	111/69	59.2	DLA n = 180	1 year
Taunton, 2018, United States,³³	RCT	101/101	Unilateral hip OA	52/49	64.5	DAA n = 52 MPA n = 49	>1 year
Tsiridis, 2020, Greece³⁵	Prospective cohort	200/200	OA	71/129	66.5	DSA n = 200	1 year
Vandeputte, 2021, Belgium²⁷	RCT; considered as prospective cohort	190/219	Primary OA	77/111	60.9	DAA n = 219	1 year

N, number of patients/hips; RCT, randomized controlled trial; CCT, controlled clinical trial; OA, osteoarthritis; DAA, direct anterior approach; PLA, posterolateral approach; PA, posterior approach; DSA, direct superior approach; DLA, direct lateral approach; MPA, mini-posterior approach.

Quality

Summary of methodological quality appraisal is provided in Appendix 2, all four RCTs^30–33 showed an overall low risk of bias. For the prospective observational studies, or considered as, the quality scores ranged from 6 to 14 out of 16 with a mean score of 11.1 ± 2.9 (70% of maximum), according to the MINORS criteria (Appendix 3). Using the GRADE approach, the overall level of evidence was rated as low, mainly based on broad confidence intervals.

Dislocation rate

A total of 2025 patients were included with a mean age of 64.6 years, 44% male, and a mean follow-up of 10.5 months (range 2–24). The overall dislocation rate was 0.79% (95% CI 0.37–1.69). Subgroup analyses showed that the most dislocations were in the posterior approaches group (18 dislocations/1306 patients, 1.38% (95% CI 0.87–2.18)). There were no significant differences between subgroups of the surgical approach (p = 0.42; Figure 3).

Figure 3.

Forest plot of surgical approach subgroup analysis.

Relative risk of dislocation in the direct anterior approach

An RR of 0.75 (95% CI 0.14–3.93) was observed in favour of the DAA (Figure 4). However, this difference was not statistically significant (p = 0.85).

Figure 4.

Forest plot of risk ratio DAA vs. other surgical approaches.

Discussion

The main findings of this systematic review with meta-analyses were that the posterior approaches group for THA provides the highest risk of dislocation (1.38%), whilst the direct anterior approach emerges with a non-significant lower risk of dislocation (RR 0.37) compared to other surgical approaches for THA. In 2025 patients treated with primary THA for osteoarthritis, the overall dislocation rate was 0.79%. It should be noted, however, that the overall level of evidence was rated as low.

When reviewing the literature on complications amongst different approaches for THA, most recent studies report no differences in major postoperative complications between various approaches. Gazendam et al.⁵ found no significant differences in dislocation between the anterior, posterior, or lateral approaches. Unlike the present study, their network meta-analysis focused on RCTs but observed similar results. Another systematic review by Miller et al.⁶ showed an RR of 0.65 (95% CI 0.44–0.95) in favor of the DAA compared to the PA. They only assessed these two approaches, without making further distinctions, but the inference is similar. Docter et al.³⁶ showed a similar RR of 0.66 (95% CI 0.56–0.77), demonstrating that the direct anterior approach has a significantly lower risk of dislocation compared to the posterior approach. However, retrospective cohort studies were also included in their study. Since these studies had the largest samples, they received more weight in their meta-analysis. Huerfano et al.³⁷ showed a non-significant difference in dislocation between the DAA and PA, however, they also included retrospective studies in their meta-analysis, and included all surgical indications. Miller et al.⁶ and Docter et al.³⁶ did not include the DSA, but it appears to be a promising technique based on the findings, and literature is emerging.^35,38 Above all, the risk of dislocation following THA is generally low according to recent literature. Nonetheless, all reviews show a similar trend, namely that the DAA for THA has a low risk of dislocation compared to other surgical approaches, although non-significant.

Dislocation risk may differ between subgroups of patients based on certain characteristics. Indeed, Gausden et al.³⁹ showed that more dislocations occur in females and also in people with older age. A population-based study by Hermansen et al.⁴⁰ also reported a higher risk of dislocation in patients older than 75 years, and the same was observed in a registry study by Peters et al.²⁴ These characteristics could not be weighted in this review because the dislocations are not specifically reported in terms of characteristics, but may have influenced the observed RR. For example, Barrett et al.³⁰ had a less favorable male/female ratio in the PA group, potentially leading to an overestimation of the RR in favor of the DAA compared to the PA. Regarding age, we found the largest age difference between treatment groups in the study of Cheng et al.³¹ However, although the PA group had higher age, the difference (3.2 years) was rather small thus overestimation of the RR would be minimal. Most studies included in this review included patients of the same age category (elderly), making risk assessment less biased by age. Furthermore, as this age group is representative of patients receiving THA due to severe osteoarthritis,² the current results are clinically relevant.

Besides patient-related characteristics, other factors could also influence the risk of dislocation, such as the surgeon's experience, component size, or patient positioning. Kyriakopoulos et al.⁴¹ indicated that several studies showed both significant and non-significant differences in other complications such as intraoperative fractures in the DAA, depending on the surgeon's learning curve. They did not mention the combination of dislocation and learning curve, but it could be interesting to know whether the experience of the surgeon plays a role in the risk of dislocation in the various surgical approaches. In recent years, larger component sizes like femoral head diameter are being used,⁴² which can have a decreasing risk of dislocation since larger component sizes naturally provide more stability to the joint. Furthermore, the use of intraoperative fluoroscopy in recent years for more accurate component positioning may decrease the risk of dislocation for several approach techniques.⁴³ Regarding patient positioning, approaches that are being performed in a supine position allow for better inclination and anteversion within previously established safe zones, therefore minimizing dislocation risk.¹⁰ On the other hand, the use of a traction table does not seem to affect this risk.⁴⁴ Lastly, the included studies were performed in different countries. Whether the risk of dislocation is influenced by different specialist care and rehabilitation protocols is unclear, almost all included studies were conducted in Western countries and therefore comparability is likely.

There are limitations to this review. First, selection bias may be present owing to certain exclusion criteria. We excluded retrospective studies due to their low level of evidence, and only included studies performed from 2009 onwards, due to compare the new DAA technique including modern used component sizes. Despite possible bias resulting from this decision, the results of this review are more useful for today's clinical care as only currently applied surgical techniques were included. Furthermore, some studies were excluded based on the language criteria, making the results more relatable to the Western clinic. Another limitation is the variability amongst the length of follow-up between the included studies. Some studies reported the timing of the complication, but most reported only the final follow-up lengths, which ranged from 2 to 24 months. Subgroup analysis for follow-up length had no added value because only two studies^24,31 reported a follow-up length of 3 months or less. However, dislocations are known to occur most frequently within the first 3 months after surgery, with around 70% in the first month.⁴⁵ Finally, including prospective observational studies reduced the level of evidence compared to only including RCT studies. However, the amount of high-quality comparative RCTs assessing dislocation risk for the DAA was limited. A strong point of this review, however, is that prospective data was used in combination with a clear outcome measure, preventing the risk of misclassification.

Conclusions

In conclusion, this systematic review with meta-analysis showed no difference between surgical approaches in view of the risk of postoperative dislocation. The choice of approach is determined by a risk-benefit analysis, and recommendations for this analysis regarding the risk of dislocations cannot be made based on the present review. The overall level of evidence for this review, as qualified by GRADE, was low. More high-quality large RCTs are needed to further identify the effects of the surgical approach technique on the risk of postoperative dislocation of the hip joint. Furthermore, to perform a subgroup analysis, important parameters such as surgical experience and the primary indication to perform THA should be recorded per subgroup.

Footnotes

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

ORCID iD

Marc Koster

Appendix 1. PubMed search

#
1	Hip Dislocation [Mesh]
2	hip dislocat[tiab] OR hip displac[tiab] OR hip dysplas[tiab] OR disloc[tiab]
3	#1 OR #2
4	Arthroplasty, Replacement, Hip [Mesh]
5	total hip arthroplast[tiab] OR THA[tiab] OR total hip replacement[tiab] OR hip prosthesis implantation[tiab] OR arthroplasty hip replacement[tiab] OR hip replacement arthroplast*[tiab]
6	#4 OR #5
7	Approach[tiab] OR posterior approach[tiab] OR anterior approach[tiab] OR anterolateral approach[tiab] OR lateral approach*[tiab]
8	#3 AND #6 AND #7

Appendix 2. Risk of bias summary (RoB 2.0 tool) for randomized controlled trials

Study	Random sequence generation	Allocation concealment	Blinding of participants and personnel	Incomplete outcome data	Selective reporting	Overall
Barrett, 2013³⁰	Green	Green	Green	Green	Green	Green
Cheng, 2018³¹	Green	Green	Green	Green	Green	Green
Mjaaland, 2019³²	Green	Green	Green	Green	Green	Green
Taunton, 2018³³	Green	Green	Green	Green	Green	Green

Green indicates low risk of bias.

Appendix 3. Risk of bias summary (MINORS criteria) for non-randomized prospective studies

Study	A clearly stated aim	Inclusion of consecutive patients	Prospective collection of data	Endpoints appropriate to the aim of the study	Unbiased assessment of the study endpoint	Follow-up period appropriate to the aim of the study	Loss to follow-up less than 5%	Prospective calculation of the study size	Total
Edipoglu, 2021²⁹	1	2	1	2	0	1	2	0	9
Peters, 2019²⁴	1	2	2	2	1	2	2	2	14
Rodriguez, 2014²⁸	2	2	2	2	1	1	1	2	13
Spaans, 2015³⁴	2	2	2	2	0	1	0	2	11
Taheriazam, 2019²⁵	1	0	2	2	0	1	0	0	6
Tsiridis, 2020³⁵	1	2	2	2	1	1	2	0	11
Vandeputte, 2021²⁷	2	1	2	2	2	1	2	2	14

Only the non-comparative part of the MINORS criteria was used (i.e. first eight questions). The criteria of MINORS [51] with 0 points when not reported, 1 when reported but not adequate, and 2 when reported and adequate. Maximum score is 16.

References

Pilot

Vehmeijer

Verburg

, et al. State of affairs with regard to total hip and knee arthroplasty. Huisarts Wet 2009; 52: 542–546.

Van Steenbergen

Mäkelä

Kärrholm

, et al. Total hip arthroplasties in the Dutch Arthroplasty Register (LROI) and the Nordic Arthroplasty Register Association (NARA): comparison of patient and procedure characteristics in 475,685 cases. Acta Orthop 2021; 92: 15–22.

Werner

Brown

. Instability after total hip arthroplasty. World J Orthop 2012; 3: 122–130.

Morrey

. Instability after total hip arthroplasty. Orthop Clin North Am 1992; 23: 237–248.

Gazendam

Bozzo

Ekhtiari

, et al. Short-term outcomes vary by surgical approach in total hip arthroplasty: a network meta-analysis. Arch Orthop Trauma Surg 2021. DOI: 10.1007/s00402-021-04131-4.

Miller

Gondusky

Kamath

, et al. Influence of surgical approach on complication risk in primary total hip arthroplasty. Acta Orthop 2018; 89: 289–294.

Peters

van Beers

van Steenbergen

, et al. 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. J Arthroplasty 2018; 33: 1786–1793.

Bal

Vallurupalli

. Minimally invasive total hip arthroplasty with the anterior approach. Indian J Orthop 2008; 42: 301–308.

Johns Hopkins Healthcare. Total hip replacement: anterior approach. https://johnshopkinshealthcare.staywellsolutionsonline.com/Conditions/Orthopedics/Test/Orthopedic/135,402 (2022, accessed 25 January 2022).

10.

Takada

Jinno

Miyatake

, et al. Supine versus lateral position for accurate positioning of acetabular cup in total hip arthroplasty using the modified Watson-Jones approach: a randomized single-blind controlled trial. Orthop Traumatol Surg Res 2019; 105: 915–922.

11.

Grammatopoulos

Gofton

Cochran

, et al. Pelvic positioning in the supine position leads to more consistent orientation of the acetabular component after total hip arthroplasty. Bone Joint J 2018; 100–b: 1280–1288.

12.

Tsukada

Wakui

. Lower dislocation rate following total hip arthroplasty via direct anterior approach than via posterior approach: five-year-average follow-up results. Open Orthop J 2015; 9: 157–162.

13.

Wang

Hou

, et al. A systematic review and meta-analysis of direct anterior approach versus posterior approach in total hip arthroplasty. J Orthop Surg Res 2018; 13: 229–224.

14.

Aggarwal

Elbuluk

Dundon

, et al. Surgical approach significantly affects the complication rates associated with total hip arthroplasty. Bone Joint J 2019; 101–B: 646–651.

15.

Klasan

Neri

Oberkircher

, et al. Complications after direct anterior versus Watson-Jones approach in total hip arthroplasty: results from a matched pair analysis on 1408 patients. BMC Musculoskelet Disord 2019; 20: 77–x.

16.

Higgins

Thomas

Chandler

, et al. Cochrane handbook for systematic reviews of interventions version 6.2 (updated February 2021). United Kingdom: Cochrane, 2021.

17.

Page

McKenzie

Bossuyt

, et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. Br Med J 2021; 372. DOI: 10.1136/bmj.n71.

18.

Ouzzani

Hammady

Fedorowicz

, et al. Rayyan---a web and mobile app for systematic reviews. Syst Rev 2016; 5: 10.

19.

Sterne

JAC

Savović

Page

, et al. Rob 2: a revised tool for assessing risk of bias in randomised trials. BMJ (Clinical Research ed) 2019; 366: l4898.

20.

Slim

Nini

Forestier

, et al. Methodological index for non-randomized studies (minors): development and validation of a new instrument. ANZ J Surg 2003; 73: 712–716.

21.

Guyatt

Oxman

Vist

, et al. GRADE: an emerging consensus on rating quality of evidence and strength of recommendations. Br Med J 2008; 336: 924–926.

22.

Dietz

Klein

Lindsey

, et al. Posterior hip precautions do not impact early recovery in total hip arthroplasty: a multicenter, randomized, controlled study. J Arthroplasty 2019; 34: S221–S227.e221.

23.

Moon

Kim

Hwang

, et al. The incidence of hip dislocation and suture failure according to two different types of posterior soft tissue repair techniques in total hip arthroplasty: a prospective randomized controlled trial. Int Orthop 2018; 42: 2049–2056.

24.

Peters

Ter Weele

Manning

, et al. Less postoperative restrictions following total hip arthroplasty with use of a posterolateral approach: a prospective, randomized, noninferiority trial. J Arthroplasty 2019; 34: 2415–2419.

25.

Taheriazam

Mohseni

Esmailiejah

, et al. Bilateral total hip arthroplasty: one-stage versus two-stage procedure. Hip Int 2019; 29: 141–146.

26.

Tetreault

Akram

, et al. Are postoperative hip precautions necessary after primary total hip arthroplasty using a posterior approach? Preliminary results of a prospective randomized trial. J Arthroplasty 2020; 35: S246–S251.

27.

Vandeputte

Vanbiervliet

Sarac

, et al. Capsular resection versus capsular repair in direct anterior approach for total hip arthroplasty: a randomized controlled trial. Bone Joint J 2021; 103–B: 321–328.

28.

Rodriguez

Deshmukh

Rathod

, et al.

Does the direct anterior approach in THA offer faster rehabilitation and comparable safety to the posterior approach?

Clin Orthop Relat Res 2014; 472: 455–463.

29.

Edipoglu

. Durability of transosseous repair of posterior soft tissues after primary total hip arthroplasty: a prospective randomized controlled trial. Arch Orthop Trauma Surg 2021. DOI: 10.1007/s00402-021-04118-1

30.

Barrett

Turner

Leopold

. Prospective randomized study of direct anterior vs postero-lateral approach for total hip arthroplasty. J Arthroplasty 2013; 28: 1634–1638.

31.

Cheng

Wallis

Taylor

, 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: 883–890.

32.

Mjaaland

Kivle

Svenningsen

, et al.

Do postoperative results differ in a randomized trial between a direct anterior and a direct lateral approach in THA?

Clin Orthop Relat Res 2019; 477: 145–155.

33.

Taunton

Trousdale

Sierra

, et al.

John charnley award: randomized clinical trial of direct anterior and miniposterior approach THA: which provides better functional recovery?

Clin Orthop Relat Res 2018; 476: 216–229.

34.

Spaans

van den Hout

, et al. The result of transmuscular versus transosseous repair of the posterior capsule on early dislocations in primary hip arthroplasty. Hip Int 2015; 25: 537–542.

35.

Tsiridis

Kenanidis

Potoupnis

, et al. Direct superior approach with standard instrumentation for total hip arthroplasty: safety and efficacy in a prospective 200-case series. Hip Int 2020; 30: 552–558.

36.

Docter

Philpott

Godkin

, et al. Comparison of intra and post-operative complication rates among surgical approaches in total hip arthroplasty: a systematic review and meta-analysis. J Orthop 2020; 20: 310–325.

37.

Huerfano

Bautista

Huerfano

, et al. Use of surgical approach is not associated with instability after primary total hip arthroplasty: a meta-analysis comparing direct anterior and posterolateral approaches. J Am Acad Orthop Surg 2021; 29: e1126–e1140.

38.

Duijnisveld

van den Hout

JAAM

Wagenmakers

, et al. No learning curve of the direct superior approach in total hip arthroplasty. Orthop Surg 2020; 12: 852–860.

39.

Gausden

Parhar

Popper

, et al. Risk factors for early dislocation following primary elective total hip arthroplasty. J Arthroplasty 2018; 33: 1567–1571.e1562.

40.

Hermansen

Viberg

Hansen

, et al. “True” cumulative incidence of and risk factors for hip dislocation within 2 years after primary total hip arthroplasty due to osteoarthritis: a nationwide population-based study from the danish hip arthroplasty register. J Bone Joint Surg Am 2021; 103: 295–302.

41.

Kyriakopoulos

Poultsides

Christofilopoulos

. Total hip arthroplasty through an anterior approach: the pros and cons. EFORT Open Rev 2018; 3: 574–583.

42.

Dutch Arthroplasty Register. Prosthesis characteristics, https://www.lroi-report.nl/hip/total-hip-arthroplasty/prosthesis-characteristics/ (2022, accessed 25 January 2022).

43.

Belyea

Lansford

Yim

. Utility of intraoperative fluoroscopic positioning of total hip arthroplasty components using a posterior and direct anterior approach. Mil Med 2022; 187: e11–e16.

44.

Wernly

Wegrzyn

Lallemand

, et al. Total hip arthroplasty through the direct anterior approach with and without the use of a traction table: a matched-control, retrospective, single-surgeon study. J Orthop Surg Res 2021; 16: 45.

45.

Xiao

Xue

. Causes of and treatment options for dislocation following total hip arthroplasty. Exp Ther Med 2019; 18: 1715–1722.