Key Points
Question
What is the association between surgical approach (anterior vs lateral or posterior) and complications in adults undergoing total hip arthroplasty?
Findings
In this population-based, retrospective cohort study that included 5986 propensity-score matched patients, an anterior surgical approach, compared with posterior or lateral approach, was significantly associated with a higher risk of major surgical complications within 1 year (2% vs 1%, respectively).
Meaning
The small but statistically significant increased risk of major surgical complications associated with the anterior approach may help inform decisions for total hip arthroplasty, although further research is needed to understand pain and functional outcomes.
Abstract
Importance
Controversy exists about the preferred surgical approach for total hip arthroplasty (THA).
Objective
To determine whether an anterior approach is associated with lower risk of complications than either a lateral or posterior approach.
Design, Setting, and Participants
Population-based retrospective cohort study of all adults in Ontario, Canada, who had undergone primary THA for osteoarthritis between April 1, 2015, and March 31, 2018. All patients were followed up over a 1-year period (study end date, March 31, 2019).
Exposures
Surgical approach (anterior vs lateral/posterior) for THA.
Main Outcomes and Measures
Major surgical complications within 1 year (composite of deep infection requiring surgery, dislocation requiring closed or open reduction, or revision surgery). Outcomes were compared among propensity-score matched groups using Cox proportional hazards regression.
Results
Of the 30 098 patients (mean [SD] age, 67 years [10.7 years]; 16 079 women [53.4%]) who underwent THA, 2995 (10%) underwent the anterior approach; 21 248 (70%), the lateral approach; and 5855 (20%) the posterior approach performed at 1 of 73 hospitals by 1 of 298 surgeons. All patients were followed up for 1 year. Compared with those undergoing the lateral or posterior approach, patients undergoing an anterior approach were younger (mean age, 65 vs 67 years; standardized difference, 0.17); had lower rates of morbid obesity (4.8% vs 7.6%; standardized difference, 0.12), diabetes (14.2% vs 19.9%; standardized difference, 0.15), and hypertension (53.4% vs 62.9%; standardized difference, 0.19); and were treated by higher-volume surgeons (median range, 111 procedures; interquartile range, 69-172 vs 77 procedures, interquartile range, 50-119 in the prior year; standardized difference, 0.55). Compared with 2993 propensity-score matched patients undergoing a lateral or posterior approach, the 2993 matched patients undergoing anterior approaches had a significantly greater risk of a major surgical complication (61 patients [2%] vs 29 patients [1%]; absolute risk difference, 1.07%; 95% CI, 0.46%-1.69%; hazard ratio, 2.07; 95% CI, 1.48 to 2.88).
Conclusions and Relevance
Among patients undergoing total hip arthroplasty, an anterior surgical approach compared with a posterior or lateral surgical approach was associated with a small but statistically significant increased risk of major surgical complications. The findings may help inform decisions about surgical approach for hip arthroplasty, although further research is needed to understand pain and functional outcomes.
This cohort study uses Ontario administrative data to estimate the risk of complications associated with posterior or lateral vs anterior surgical approaches to total hip replacement arthroplasty.
Introduction
Total hip arthroplasty (THA) enables patients disabled by arthritic hip pain to improve their quality of life to a degree greater than any other elective procedure.1,2 More than 500 000 primary THAs were performed in the United States in 2018, with numbers steadily increasing.3 THA design has been similar for more than 20 years.1 Current controversy instead relates to the surgical approach: lateral, posterior, and, more recently, anterior.4
Lateral and posterior approaches are performed with the patient on their side with excellent visualization for component positioning and are easily extensile if complications occur.5 Potential disadvantages of the lateral approach include splitting the abductor muscles, which may cause limping, whereas the posterior approach has been associated with a higher historical dislocation rate.5 The anterior approach is performed with the patient supine and exploits a natural plane between muscles to theoretically reduce these complications.5,6,7,8 However, higher complication rates have been reported including nerve injuries, fractures, and infections.5,6,7,8
Evidence comparing approaches is limited to expert opinion, case series, and small unblinded trials.5,6,7,8 Results of this research are mixed and limited in generalizability beyond specialized arthroplasty centers.9 Systematic reviews of this limited evidence base found no differences in patient function or complication rates between approaches.5,6,7,8 Nevertheless, media reports10 and surgeon promotion11 of better outcomes with the anterior approach have been widespread and performance of anterior THAs in the United States was estimated to have increased from 12% in 2009 to 40% in 2018.4
Reflecting technical evolution in the anterior approach and public interest in the procedure, in 2015 the Canadian Institute for Health Information began identifying the surgical approach used to conduct each THA in the country.12 The objective of this study was to use these population-based data to determine whether an anterior approach was associated with lower risk of surgical complications than were associated with either lateral or posterior approaches.
Methods
Ethics Approval
Use of the data in this project was authorized by the ICES Privacy and Compliance Office under section 45 of Ontario’s Personal Health Information Protection Act, which does not require review by a research ethics board or individual patient consent.
Data Sources and Setting
This was a population-based, propensity-score matched, retrospective cohort study of patients undergoing THA in Ontario (Canada’s most populous province). Administrative health care data housed at ICES, an independent not-for-profit health services research institute funded by the Ontario Ministry of Health, was used. All their medical care, physician and hospital information, and demographic characteristics of Ontario residents are recorded in this database. Validated algorithms used previously to identify patients undergoing THA, covariates and outcomes in the database were retained.13
Patients
The cohort comprised all consecutive adults (>18 years) in Ontario who received their first primary elective THA for osteoarthritis between April 1, 2015, and March 31, 2018. The beginning of the accrual period was selected on the basis of when a variable identifying the surgical approach for THA was introduced.12 All patients were followed up for 1 year (study end date March 31, 2019).
Main Exposure
Surgical approach was categorized using the Canadian Classification of Health Interventions CCI codes.12 Patients undergoing lateral and posterior approaches were grouped together and compared with the anterior approach in the primary analysis a priori and analyzed separately in sensitivity analyses post hoc.
Covariates
Validated algorithms identified patients with a history of preexisting cardiovascular disease,14 congestive heart failure,15 diabetes,16 hypertension,17 asthma,18 and chronic obstructive pulmonary disease (COPD).19 Morbid obesity (body mass index [BMI], calculated as weight in kilograms divided by height in meters squared, >40) and counseling for smoking cessation were identified using physician billing codes. Additional comorbidities listed on hospital discharge abstracts in the 3 years before the index THA admission were categorized according to an adaptation of the Charlson Comorbidity Index.20 The Johns Hopkins ACG System (version 10)21 was used to classify patient frailty.21 Those living in rural areas were identified. The neighborhood income quintile was used as a surrogate for socioeconomic status. This variable categorizes each patient into 1 of 5 population groups, with the lowest quintile referring to the least affluent.22 To characterize the environment in which each procedure was performed, surgeon and hospital volume were defined as the total number of hip arthroplasty procedures (both primary and revision) performed by the surgeon and hospital in the 365 days prior to the date of surgery. Surgeon and hospital volume covariates were permitted to change for each subsequent procedure performed by the same surgeon and hospital.13
Outcomes
The primary study outcome was the occurrence of a major surgical complication within 1 year of surgery. Because the rates of these complications were expected to be low (<1%), a composite complication was defined a priori as the primary outcome. This composite encompassed revision arthroplasty, deep surgical site infection requiring surgery, and hip dislocation requiring open or closed reduction. Each major surgical complication was also considered individually as a secondary outcome. Other secondary outcomes were (1) length of stay considered as a continuous variable in days; (2) surgery duration measured as the total time elapsed in minutes between the entry into and exit out of the operating room23; (3) readmission to at any Ontario hospital; and (4) and presentation to any Ontario emergency department, the latter 2 points within 30 days.
Statistical Analysis
Patients in the cohort were classified according to surgical approach (anterior vs lateral or posterior). Baseline cohort characteristics were reported using proportions and means (SDs) or medians (interquartile ranges [IQRs]) if skewed. Patients who had an anterior approach were matched to those who had either a lateral or a posterior approach 1:1 by greedy matching on the logit of propensity scores with a caliper of 0.2 × SD.24 Variables thought to be potential confounders were entered into the propensity score and included sociodemographics (age, sex, rural residence, income quintile, year of surgery), patient health status (Charlson score, frailty, hypertension, COPD, congestive heart failure, diabetes, coronary artery disease, BMI, counseling on smoking cessation) and physician and hospital characteristics (annual surgeon and hospital volume). Standardized differences for all covariates were calculated before and after matching, with 10% or more considered indicative of imbalance.25 Primary and secondary outcomes were compared between the 2 groups after matching. Generalized estimating equations (GEE) calculated percent absolute risk differences (% absolute risk difference [RD], with 95% CIs) for categorical outcomes. The cumulative incidence of major surgical complication events was calculated using the Kaplan-Meier method, and the log-rank test was used to calculate the P value. Hazard ratios (HRs) for the occurrence of surgical complications were also calculated using a Cox proportional hazards model with robust variance estimation that accounted for pair matching.26 Mortality was not a competing risk because there were no deaths among matched patients within 1 year of surgery. The proportionality assumption was tested by graphical methods and was met (eFigure 1 in the Supplement). For continuous outcomes, medians with IQRs for within-pair differences (anterior vs lateral or posterior) were calculated. All analyses were performed at ICES using SAS version 9.3 (SAS Institute Inc). The 2-sided type I error probability was set to .05. Because of the potential for type I error due to multiple comparisons, findings for analyses of secondary end points should be interpreted as exploratory. Missing data, which was less than 1% for all variables considered, were excluded from regression models.
Sensitivity Analyses
Four post hoc sensitivity analyses were conducted. First, outcomes were analyzed between lateral and posterior approaches separately (eAppendix 1 in the Supplement). Second, analyses adjusting for surgeon experience with the anterior approach were conducted (eAppendix 2 in the Supplement). Third, GEE were used to account for potential clustering of complications at the hospital and surgeon levels (eAppendix 3 in the Supplement). Fourth, the number of surgeons with major surgical complications were compared between approach types after matching (eTable in the Supplement).
Results
Patient Characteristics Before Matching
Of the 30 098 patients (mean [SD] age, 67 years [10.7 years] years; 16 079 women [53.4%]) who underwent THA, 2995 (10%) underwent the anterior approach; 21 248 (70%), the lateral approach; and 5855 (20%) posterior approach at 1 of 73 hospitals and performed by 1 of 298 surgeons. All patients were followed up at 1 year (Table 1). Compared with patients undergoing either the lateral or posterior approaches, those undergoing the anterior approaches were younger (mean age 65 vs 67 years, standardized difference, 0.17); had lower rates of morbid obesity (4.8% vs 7.6%, standardized difference, 0.12), diabetes (14.2% vs 19.9%, standardized difference, 0.15), and hypertension (53.4% vs 62.9%, standardized difference, 0.19); and were treated by higher-volume surgeons who performed a median of 111 (IQR, 69-172) procedures vs 77 procedures (IQR, 50-119) in the prior year standardized difference, 0.55) at hospitals that had a median of 433 (IQR, 191-651) vs 349 (IQR, 234-533) THAs in the prior year, standardized difference, 0.12). The anterior approach became increasingly common from 8% of all THAs in 2015 to 12% in 2017. Before matching, patients who had undergone the anterior approach had a significantly greater risk of a major surgical complication within 1 year: 61 of 2995 (2%) vs 398 of 27 103 (1.5%) (absolute RD, 0.57%; 95% CI, 0.04%-1.09%; HR, 1.41; 95% CI, 1.08-1.85).
Table 1. Characteristics of Total HA Recipients by Surgical Approach Before and After Matchinga.
| No. (%) of patients | SDMb | No. (%) of patients | SDMb | |||
|---|---|---|---|---|---|---|
| Before matching | After matching | |||||
| Anterior approach | Lateral or posterior approach | Anterior approach | Lateral or posterior approach | |||
| No. of patients | 2995 | Lateral, 21 248 Posterior, 5855 |
2993 | Lateral, 2326; Posterior, 667 |
||
| No. of surgeons | 134 | 297 | 133 | 263 | ||
| Demographics | ||||||
| Age, mean (SD), y | 65.3 (11.4) | 67.2 (10.6) | 0.17 | 65.3 (11.4) | 65.3 (11.1) | 0 |
| Men | 1494 (49.9) | 12 525 (46.2) | 0.07 | 1493 (49.9) | 1469 (49.1) | 0.02 |
| Women | 1501 (50.1) | 14 578 (53.8) | 0.07 | 1500 (50.1) | 1524 (50.9) | 0.02 |
| Rural residence | 548 (18.3) | 4237 (15.6) | 0.07 | 548 (18.3) | 482 (16.1) | 0.06 |
| Income quintile | ||||||
| Lowest | 440 (14.7) | 4464 (16.5) | 0.05 | 440 (14.7) | 433 (14.5) | 0.01 |
| 2 | 533 (17.8) | 5248 (19.4) | 0.04 | 533 (17.8) | 530 (17.7) | 0 |
| 3 | 604 (20.2) | 5235 (19.3) | 0.02 | 604 (20.2) | 620 (20.7) | 0.01 |
| 4 | 612 (20.4) | 5586 (20.6) | 0 | 612 (20.4) | 613 (20.5) | 0 |
| Highest | 804 (26.8) | 6540 (24.1) | 0.06 | 804 (26.9) | 797 (26.6) | 0.01 |
| Comorbidities | ||||||
| Hypertension | 1600 (53.4) | 17 039 (62.9) | 0.19 | 1599 (53.4) | 1597 (53.4) | 0 |
| Diabetes | 425 (14.2) | 5381 (19.9) | 0.15 | 425 (14.2) | 430 (14.4) | 0 |
| COPD | 449 (15.0) | 4892 (18.0) | 0.08 | 449 (15.0) | 430 (14.4) | 0.02 |
| Smoking cessation counseling | 190 (6.3) | 1691 (6.2) | 0 | 190 (6.3) | 164 (5.5) | 0.04 |
| BMI >40 | 143 (4.8) | 2069 (7.6) | 0.12 | 143 (4.8) | 166 (5.5) | 0.03 |
| Frail | 147 (4.9) | 1737 (6.4) | 0.06 | 147 (4.9) | 141 (4.7) | 0.01 |
| Congestive heart failure | 109 (3.6) | 1275 (4.7) | 0.05 | 109 (3.6) | 119 (4.0) | 0.02 |
| Coronary artery disease | 85 (2.8) | 934 (3.4) | 0.03 | 85 (2.8) | 85 (2.8) | 0 |
| Asthma | 75 (2.5) | 875 (3.2) | 0.04 | 73 (2.4) | 81 (2.7) | 0.02 |
| Charlson scorec | ||||||
| 0 | 2547 (85.0) | 21 124 (77.9) | 0.18 | 2546 (85.1) | 2543 (85.0) | 0 |
| 1 | 259 (8.6) | 3585 (13.2) | 0.15 | 259 (8.7) | 249 (8.3) | 0.01 |
| 2 | 123 (4.1) | 1569 (5.8) | 0.08 | 122 (4.1) | 121 (4.0) | 0 |
| ≥3 | 66 (2.2) | 825 (3.0) | 0.05 | 66 (2.2) | 80 (2.7) | 0.03 |
| Fiscal year of procedure | ||||||
| 2015 | 767 (25.6) | 8665 (32.0) | 0.14 | 766 (25.6) | 822 (27.5) | 0.04 |
| 2016 | 938 (31.3) | 9205 (34.0) | 0.06 | 937 (31.3) | 968 (32.3) | 0.02 |
| 2017 | 1290 (43.1) | 9233 (34.1) | 0.19 | 1290 (43.1) | 1203 (40.2) | 0.06 |
| Procedure volume, median (IQR)d | ||||||
| Hospital | 433 (191-651) | 349 (234-533) | 0.12 | 433 (191-651) | 385 (262-611) | 0.03 |
| Surgeon | 111 (69-172) | 77 (50-119) | 0.55 | 111 (69-172) | 118 (71-161) | 0 |
Abbreviations: BMI, body mass index, calculated as weight in kilograms divided by height in meters squared; COPD, chronic obstructive pulmonary disease; IQR, interquartile range; SDM, standardized difference of the mean.
Greedy matching occurred 1:1 on the logit of a propensity score with a caliper of 0.2 SD.
SDMs of 0.1 or more represent meaningful differences in covariates between groups before and after matching.
Deyo-Charlson score is a measure of patient comorbidity (prior to their hip replacement) and ranges from 0 (lowest complication risk) to 3 or more (highest complication risk). Patients may also be classified as having no prior hospital admissions.
Number of hip arthroplasty procedures performed in the 365 days prior to the date of surgery.
Outcomes After Matching
A total of 2993 patients (>99%) who had undergone an anterior approach were matched to a patient who had undergone either a lateral or posterior approach with standardized differences of less than 10% for all covariates, indicating an adequate match (Table 2). After matching, patients who had undergone an anterior approach were at a significantly greater risk of experiencing a major surgical complication within 1 year (61 [2%] vs 29 [1%]; absolute RD, 1.07%; 95% CI, 0.46%-1.69%; HR, 2.07; 95% CI, 1.48 to 2.88). The cumulative incidence of major surgical complications calculated using the Kaplan-Meier method is shown in the Figure and the log-rank P value <.001.
Table 2. Comparison of Primary and Secondary Outcomes Between Propensity-score Matched Groups.
| Outcome | No. (%) of patients | Absolute risk difference (95% CI), %b |
Hazard ratio (95% CI)c |
|
|---|---|---|---|---|
| Anterior approach (n = 2993) |
Lateral or posterior approach (n = 2993)a |
|||
| Primary outcome | ||||
| Major surgical complication, within 1 y | 61 (2.0) | 29 (1.0) | 1.07 (0.46 to 1.69) | 2.07 (1.48 to 2.88) |
| Secondary outcomes | ||||
| Categorical | ||||
| Surgical complications ≤1 y | ||||
| Deep infection | 36 (1.2) | 11 (0.4) | 0.84 (0.39 to 1.29) | 3.27 (1.91 to 5.62) |
| Dislocation | 21 (0.7) | 8 (0.3) | 0.44 (0.08 to 0.79) | 2.63 (1.40 to 4.93) |
| Revision | 36 (1.2) | 20 (0.7) | 0.54 (0.05 to 1.01) | 1.75 (1.17 to 2.62) |
| ED ≤30 d | 449 (15.0) | 433 (14.5) | 0.54 (−1.26 to 2.33) | |
| Readmission ≤30 d | 7 (0.2) | 10 (0.3) | −0.10 (−0.37 to 0.17) | |
| Continuous | Median (IQR) within-pair differencesd | |||
| Surgery time, median (IQR), min | 108 (94 to 130) | 99 (84 to 118) | 11 (−13 to 36) | |
| LOS, median (IQR), d | 2 (1 to 3) | 2 (2 to 3) | −1 (−2 to 0) | |
Abbreviations: ED, emergency department; IQR, interquartile range; LOS length of stay.
Lateral, 2326 patients; posterior, 667 patients.
Expressed as a percentage (with 95% CIs) calculated using generalized estimating equations.
Hazard ratios for occurrence of each surgical complication were also calculated using a Cox proportional hazards model with robust variance estimation that accounted for pair matching. The reference group was use of either the lateral or posterior approach.
Median and IQRs for within-pair differences (anterior vs lateral or posterior) after matching for surgical duration and acute length of stay were calculated.
Figure. Cumulative Incidence of Infection, Dislocation, or Revision Among Patients Who Underwent Total Hip Arthroplasty.
Breaking this down further by specific complication, patients who had an anterior approach had a significantly greater risk of deep infection that required surgery (36 [1.2%] vs 11 [0.4%]; absolute RD, 0.84%; 95% CI, 0.39%-1.29%; HR, 3.27; 95% CI, 1.91-5.62), dislocation requiring closed or open reduction (21 [0.7%] vs 8 [0.3%]; absolute RD, 0.44%; 95% CI, 0.08%-0.79%; HR, 2.63, 95% CI, 1.40-4.93), and revision arthroplasty (36 [1.2%] vs 20 [0.7%]; absolute RD, 0.54%; 95% CI, 0.05%-1.01%; HR, 1.75; 95% CI, 1.17-2.52).
Patients who had undergone an anterior approach had a significantly longer median surgical duration of 108 minutes (IQR, 94 to 130 minutes) vs 99 minutes (IQR, 84 to 118 minutes), for a median difference 11 minutes (IQR, –13 to 36 minutes; P<.001), but a significantly shorter median length of stay of 2 days (IQR, 1 to 3 days) vs 2 days (IQR, 2-3 days), for a median difference of –1 (IQR, –2 to 0 days; P<.001). There was no significant difference in the rate of return to the emergency department with 449 patients (15.0%) vs 433 (14.5%), for an absolute RD of 0.54% (95% CI, –1.26% to 2.33%) or readmission to the hospital within 30 days of surgery with 7 patients (0.2%) vs 10 (0.3%), absolute RD of –0.10% (95% CI, –0.37% to 0.17%).
Relationships between approach type and complications were robust to sensitivity analyses accounting for (1) lateral and posterior approaches separately (2) clustering at the surgeon and hospital level, and (3) surgeon experience with the anterior approach (eAppendexes 2 and 3 in the Supplement). Twenty-seven of 133 surgeons (20%) in the anterior group that had a major complication compared with 24 of 263 surgeons (9%) in the lateral and posterior group (eTable in the Supplement).
Discussion
In this retrospective cohort study of patients who had undergone THA in Ontario, Canada, those who had operations involving an anterior approach compared with those who had operations involving a lateral or posterior approach had a small but statistically significant higher risk of major surgical complications within 1 year (deep infection, dislocation, revision surgery).
Controversy exists among arthroplasty surgeons and patients about the best surgical approach for THA. Those who have summarized the evidence on this topic have advocated for large randomized clinical trials comparing approaches to determine which is preferable.5 Given the known placebo effects of orthopedic procedures,27 it may be debated whether an unbiased randomized trial of functional outcomes can be conducted when surgeons and patients cannot be blinded to their surgical approach. Feasibility is also a concern because major surgical complications (such as infection and dislocation) following THA are rare (<1%).
The finding from this population-based study that an anterior approach has a risk profile significantly different from its public perception may inform clinical decision-making for the increasing number of patients with hip arthritis and surgeons performing THA. For example, a survey of surgeon websites found that potential benefits of an anterior approach were mentioned 9 times more frequently than any potential risk of the procedure.11 Emphasizing disclosure of the increased rate of major surgical complications associated with an anterior approach is important in this context.
There are several possible explanations for an association between surgical approach and complications. Infections may be due to proximity of the anterior wound to the groin-abdominal fold, less robust fascia available for deep closure, use of intraoperative fluoroscopy, and longer operative times.28,29 Tendon and capsular releases that comprise a standard part of the modern anterior approach may be responsible for the higher dislocation rate. Femoral exposure with the anterior approach may be more challenging despite releases and use of a traction table, potentially leading to component malposition, fracture, and thus subsequent revision surgery.30
These challenges may not be insurmountable, and there is evidence that increased experience with the anterior approach, often described as a learning curve, may mitigate some of these complications.5 Although outcomes may be different in the hands of different surgeons, with different experience levels, the purpose of this population-based study was to assess outcomes of the different approaches as they currently are being performed. Prior research on this topic has limited generalizability because only patients from specialized arthroplasty centers were included.5 Nevertheless, surgeon experience, or lack thereof, is unlikely to be responsible for the findings herein, given that anterior approaches in the study were more likely performed by higher–volume arthroplasty surgeons at higher volume arthroplasty centers where few complications would be expected. Relationships between approach type and complications were also robust to sensitivity analyses accounting for (1) clustering at the surgeon and hospital level and (2) surgeon experience with the anterior approach.
This study used recent population-based data from a heterogenous surgeon and patient pool in the Canadian province with the largest population and is generalizable to surgeons and patients contemplating anterior approaches in the United States4 and Europe,5 where THA is performed predominantly through lateral and posterior approaches. All hip replacements for osteoarthritis in Ontario were identified during the study period, as well as any subsequent complication, even if patients were lost to follow-up from their original surgeon. Major surgical complications after THA are rare (<1%) and small sample sizes may explain why prior research has failed to find differences in outcomes between approaches.5,6,7,8 The large sample size of this study enabled power to detect a significant difference in the rates of these complications. Techniques referenced in some prior literature are also outdated as the technical aspects of each surgical approach has evolved.30 Data from this study was collected between 2015 and 2019 and thus reflects more contemporary surgical practices. Several potential confounders associated with increased risk of surgical complications after THA were also measured and controlled for. These include morbid obesity,31 diabetes,32 hypertension,33 congestive heart failure,34 COPD,35 frailty,36 low socioeconomic status,37 and surgeon inexperience.13 Prior to matching, several of these factors were significantly less common among patients receiving anterior approaches and would have predisposed this group to having lower complications if the approach used were a neutral factor.
Limitations
The study has several limitations. First, no information was available in the administrative database about specific postoperative protocols. Dislocations in the anterior group may be explained, in part, by surgeons’ leniency with postoperative hip precautions for these patients.38 Second, there was no information about short-term functional outcomes and pain scores cited by expert opinion as the main advantage of an anterior approach.30 The significant difference in length of stay may reflect this. However, some of these perceived benefits of the anterior approach may be secondary to the type of patients who receive them. The anterior-approach group was younger, healthier, and plausibly more physically able and motivated to be discharged earlier in ways that could not be measured.31 Third, specific THA implants were not identified but different centers and surgeons use similar implant types in Canada’s publicly funded health care system.39 Fourth, 2 complications more commonly reported with anterior approaches—meralgia paresthetica40 and periprosthetic fractures5—were not assessed. Though fractures necessitating revision arthroplasty would have been captured, this limitation may have underestimated the risk posed by the anterior approach.
Conclusions
Among patients undergoing total hip arthroplasty, an anterior surgical approach compared with a posterior or lateral surgical approach was associated with a small but statistically significant increased risk of major surgical complications. The findings may help inform decisions about surgical approach for hip arthroplasty, although further research is needed to understand pain and functional outcomes.
eFigure 1. Testing the proportional hazard assumption
eAppendix 1. Results of lateral and posterior approaches analyzed separately
eFigure 2. Cumulative Incidence of Major Surgical Complications in Patients Undergoing Total Hip Arthroplasty by Surgical Approach Type After Matching
eAppendix 2. Analysis accounting for experience with the anterior approach
eAppendix 3. Analyses accounting for clustering
eTable. Number of surgeons with major surgical complications by approach after matching
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
eFigure 1. Testing the proportional hazard assumption
eAppendix 1. Results of lateral and posterior approaches analyzed separately
eFigure 2. Cumulative Incidence of Major Surgical Complications in Patients Undergoing Total Hip Arthroplasty by Surgical Approach Type After Matching
eAppendix 2. Analysis accounting for experience with the anterior approach
eAppendix 3. Analyses accounting for clustering
eTable. Number of surgeons with major surgical complications by approach after matching