Capsular resection versus capsular repair in direct anterior approach for total hip arthroplasty: a randomized controlled trial

Indirect comparisons of traction table versus standard table in total hip arthroplasty through direct anterior approach: a systematic review and frequentist network meta-analysis

BACKGROUND

It remains unclear whether the use of an orthopaedic traction table (TT) in direct anterior approach (DAA) total hip arthroplasty (THA) results in better outcomes. The aim of this systematic review and network meta-analysis was to compare the THA outcomes through DAA on a standard operating table and the THA outcomes through DAA on a TT.

METHODS

PubMed, Epistemonikos, and Google Scholar were searched for relevant randomized controlled trials (RCTs) up to 01 January 2024. An indirect comparison in network meta-analysis was performed to assess treatment effects between DAA on a TT and DAA on a standard table, using fixed-effects and random-effects models estimated with frequentist approach and consistency assumption. Standardized mean differences (SMDs) with 95% confidence intervals (CIs) were estimated for continuous variables and odds ratios (ORs) with 95% CIs were estimated for binary variables.

RESULTS

The systematic review of the literature identified 43 RCTs with a total of 2,258 patients. DAA with TT had a 102.3 mL higher intraoperative blood loss and a 0.6 mmol/L lower Hb 3 days postoperatively compared with DAA without TT (SMD = 102.33, 95% CI 47.62 to 157.04; SMD = - 0.60, 95% CI  - 1.19 to - 0.00). DAA with TT had a 0.15 lower periprosthetic fracture OR compared with DAA without TT (OR 0.15, 95% CI 0.03 to 0.86). There were no further significant differences in surgical, radiological, functional outcomes and in complication rates.

CONCLUSION

Based on our findings and taking into account the limitations, we recommend that particular attention be paid to the risk of periprosthetic fracture in DAA on a standard operating table and blood loss in DAA with TT. Since numerous other surgical, radiological, functional outcome parameters and other complication rates studied showed no significant difference between DAA on a standard operating table and DAA with TT, no recommendation for a change in surgical technique seems justified.

LEVEL OF EVIDENCE

Level I evidence, because this is a systematic review and meta-analysis of randomized controlled trials.

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

BACKGROUND

Dislocation after total hip arthroplasty (THA) is a primary reason for THA revision. During THA through the direct anterior approach (DAA), the iliofemoral ligament, which provides the main resistance to external rotation (ER) of the hip, is commonly partially transected. We asked: (1) what is the contribution of the medial iliofemoral ligament to resisting ER after DAA THA? and (2) how much resistance to ER can be restored by repairing the ligament?

METHODS

A fellowship-trained surgeon performed DAA THA on 9 cadaveric specimens. The specimens were computed tomography scanned before and after implantation. Prior to testing, the ER range of motion of each specimen to impingement in neutral and 10° of extension was computationally predicted. Each specimen was tested on a 6-degrees-of-freedom robotic manipulator. The pelvis was placed in neutral and 10° of extension. The femur was externally rotated until it reached the specimen's impingement target. Total ER torque was recorded with the medial iliofemoral ligament intact, after transecting the ligament, and after repair. Torque at extremes of motion was calculated for each condition. To isolate the contribution of the native ligament, the torque for the transected state was subtracted from both the native and repaired conditions.

RESULTS

The medial iliofemoral ligament contributed an average of 68% (range, 34 to 87) of the total torque at the extreme of motion in neutral and 80% (58 to 97) in 10⁰ of extension. The repaired ligament contributed 17% (1 to 54) of the total torque at the extreme of motion in neutral and 14% (5 to 38) in 10⁰ of extension, restoring on average 18 to 25% of the native resistance against ER.

CONCLUSIONS

The medial iliofemoral ligament was an important contributor to the hip torque at the extreme of motion during ER. Repairing the ligament restored a fraction of its ability to generate torque to resist ER.

Can Patients Who Have Low-Grade Hip Osteoarthritis Expect the Same Outcome After Total Hip Arthroplasty Compared to Those Who Have End-Stage Osteoarthritis? - A Matched Case-Control Study

BACKGROUND

Total hip arthroplasty (THA) is an effective procedure for patients with end-stage hip osteoarthritis (OA). In addition, when hip preservation surgery is no longer indicated due to the presence of early or mild arthritic changes, THA can also be considered. Whether these patients can expect the same outcome after THA as patients who have end-stage OA remains unclear. The goal of this study was to compare the clinical outcomes after THA of patients who have low-grade OA versus a matched cohort with end-stage OA.

METHODS

This is a retrospective, single-center, multisurgeon case-control study in a high-volume referral center. Based on a cohort of 2,189 primary anterior approach THAs (1,815 patients), 50 low-grade OA cases were matched 1:1 by age, sex, and body mass index to 50 controls who have end-stage OA. Patient-reported outcome measures (PROMs) were Hip Disability and Osteoarthritis Outcome Scores and Short Form-36.

RESULTS

No significant differences in preoperative PROMs between low-grade and end-stage OA patients were found, except for 36-item Short Form Survey pain (33.0 versus 41.0; P = .045). In both groups a significant improvement of all PROMs was found postoperatively. However, all Hip Disability and Osteoarthritis Outcome Scores were significantly lower in the low-grade OA group compared to the end-stage OA group. In the group with low-grade OA, a significantly lower percentage of patients achieved the minimal clinically important difference and substantial clinical benefit after THA compared to the group with end-stage OA.

CONCLUSIONS

Patients who have low-grade OA can expect substantial clinical improvement after THA. However, the improvement is lower compared to patients who have end-stage OA. A thorough understanding of the factors that may lead to inferior clinical outcomes is imperative to improving the indications for THA in individuals who have low-grade OA.

Change in hip laxity after anterior capsular suture in total hip arthroplasty using direct anterior approach

It is clinically unclear whether anterior capsular suture improves hip laxity in total hip arthroplasty using direct anterior approach (DAA-THA). This study aimed to clarify the impact of anterior capsular suture for hip laxity in DAA-THA. In this study, 121 hips of 112 patients who underwent DAA-THA were prospectively enrolled. Mean age was 64.7 ± 10.1 years, and the subjects consisted of 35 hips in 32 men and 86 hips in 80 women. To evaluate hip laxity after implantation, axial head transfer distance (HTD) when the hip was pulled axially at 15 kg was compared before and after anterior capsular suture at the hip intermediate and 10° extension positions. HTD in the intermediate and 10° extension positions averaged 5.9 ± 4.6 mm and 6.3 ± 4.6 mm before the suture, and 2.6 ± 2.7 mm and 2.9 ± 3.1 mm after the suture, respectively. HTD after the suture significantly decreased in both hip positions (p < 0.0001). The amount of change by the suture was greater in cases with greater pre-suturing HTD. In DAA-THA, the anterior capsular suture significantly improved hip laxity against axial traction force, it may contribute to improvement of postoperative hip stability, especially in cases with greater laxity before the suture.

Combined Anteversion Threshold to Avoid Anterior Dislocation in Primary Total Hip Arthroplasty Performed Through the Direct Anterior Approach

BACKGROUND

Component malposition in total hip arthroplasty (THA) can lead to dislocation, early implant failure, and revision surgery. As the surgical approach might affect the targeted combined anteversion (CA) of THA components, the present study aimed to evaluate the optimal CA threshold to avoid anterior dislocation in primary THA performed through a direct anterior approach (DAA).

METHODS

A total of 1,176 THAs in 1,147 consecutive patients (men: 593, women: 554) who had an average age of 63 years (range, 24 to 91) and a mean body mass index of 29 (range, 15 to 48) were identified. Medical records were reviewed for dislocation, whereas postoperative radiographs were assessed to measure the acetabular inclination and CA using a previously validated radiographic method.

RESULTS

An anterior dislocation occurred in 19 patients at an average of 40 days postoperatively. The average CA in patients who did and did not have a dislocation was 66 ± 8° and 45 ± 11°, respectively (P < .001). In 5 of 19 of the patients, a THA was performed for secondary osteoarthritis and 17 of 19 had a 28-mm femoral head. A CA ≥ 60° yielded a sensitivity of 93% and specificity of 90% for predicting an anterior dislocation in the present cohort. A CA ≥ 60° was associated with a significantly higher risk of anterior dislocation (odds ratio = 75.6; P < .001) compared to patients who had a CA<60 points.

CONCLUSION

The optimal CA to avoid anterior dislocations in THA performed through the DAA should be less than 60°.

LEVEL OF EVIDENCE

Cross-sectional study, Level III.

Instantaneous Generation of Subject-Specific Finite Element Models of the Hip Capsule

Subject-specific hip capsule models could offer insights into impingement and dislocation risk when coupled with computer-aided surgery, but model calibration is time-consuming using traditional techniques. This study developed a framework for instantaneously generating subject-specific finite element (FE) capsule representations from regression models trained with a probabilistic approach. A validated FE model of the implanted hip capsule was evaluated probabilistically to generate a training dataset relating capsule geometry and material properties to hip laxity. Multivariate regression models were trained using 90% of trials to predict capsule properties based on hip laxity and attachment site information. The regression models were validated using the remaining 10% of the training set by comparing differences in hip laxity between the original trials and the regression-derived capsules. Root mean square errors (RMSEs) in laxity predictions ranged from 1.8° to 2.3°, depending on the type of laxity used in the training set. The RMSE, when predicting the laxity measured from five cadaveric specimens with total hip arthroplasty, was 4.5°. Model generation time was reduced from days to milliseconds. The results demonstrated the potential of regression-based training to instantaneously generate subject-specific FE models and have implications for integrating subject-specific capsule models into surgical planning software.

Risk Factors for Iliopsoas Tendinopathy After Anterior Approach Total Hip Arthroplasty

BACKGROUND

Iliopsoas tendinopathy is a cause of groin pain following total hip arthroplasty (THA). With the anterior approach becoming increasingly popular, our aim was to determine the prevalence of iliopsoas tendinopathy following anterior approach THA, to identify risk factors and to determine an influence on patient-reported outcomes.

METHODS

This is a retrospective case-control study of prospectively recorded data on 2,120 primary anterior approach THA (1,815 patients). The diagnosis of iliopsoas tendinopathy was based on (1) persistent postoperative groin pain, triggered by hip flexion; (2) absence of dislocation, infection, loosening, or fracture; and (3) decrease of pain after fluoroscopy-guided iliopsoas tendon sheet injection with xylocaine and corticosteroid. Outcomes included hip reconstruction (inclination/anteversion and leg-length), complication rates, reoperation rates, and patient-reported outcomes including Hip disability and Osteoarthritis Outcome Score.

RESULTS

Forty four patients (46 THAs) (2.2%) were diagnosed with iliopsoas tendinopathy. They were younger than patients who did not have iliopsoas tendinopathy (51 years [range, 27-76] versus 62 years [range, 20-90]; P < .001). Logistic regression analyses demonstrated that younger age (P < .001) and presence of a spine fusion (P = .008) (odds ratio 4.6) were the significant predictors of iliopsoas tendinopathy. These patients had lower Hip disability and Osteoarthritis Outcome scores, reported more often low back pain (odds ratio 4.8), and greater trochanter pain (odds ratio 5.4).

CONCLUSION

We found an incidence of 2.2% of iliopsoas tendinopathy patients after anterior approach THA that compromised outcomes. Younger age and previous spine fusion were identified as most important risk factors. These patients were 5 times more likely to report low back pain and greater trochanter pain post-THA.

Is there any clinical advantage of capsular repair over capsular resection for total hip arthroplasty? An updated systematic review and meta-analysis

INTRODUCTION

Although several surgical approaches, with or without capsular repair, can be used during total hip arthroplasty (THA), there is no clear evidence that capsular repair provides a clinical advantage post-surgery, regardless of surgical approach. This systematic review and meta-analysis evaluated whether capsular repair using various surgical approaches provides a clinical advantage over capsular resection post-THA.

METHODS

This study was conducted in accordance with the preferred reporting items for systematic reviews and meta-analyses (PRISMA) 2020 checklist for systematic reviews and meta-analyses. Multiple comprehensive literature searches were performed. Results were summarized qualitatively as meta-analysis of pooled odds ratios, and the standardized mean difference, with 95% confidence intervals for each group: capsular repair or capsular resection. A P value < 0.05 was considered statistically significant. Each study was evaluated for the risk of bias. Publication bias was also assessed.

RESULTS

A total of 12 studies were included after screening and eligibility assessment. The odds ratio for hip dislocation after capsular repair was 0.14 (P < 0.00001). The standard mean difference of the Harris Hip Score (HHS) after capsular repair was 1.11 (P = 0.02). There were no significant differences between groups with respect to operation time (P = 0.79) and blood loss (P = 0.42).

CONCLUSION

The current meta-analysis suggests that capsular repair leads to lower dislocation rates and a better HHS after THA.

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

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.

Perioperative Operating Room Efficiency Can Make Simultaneous Bilateral Total Hip Arthroplasty Cost-effective: A Proposal for a Value-sharing Model

Background

Increasing demand for total hip arthroplasty (THA) and rising health-care costs have led hospitals to improve operating room (OR) efficiency. We compare the cost-effectiveness of a simultaneous bilateral THA to that of staged unilateral procedures following the implementation of OR efficiency strategies.

Methods

Between 2017 and 2019, 446 simultaneous and 238 staged bilateral primary THA patients (mean age 61.3 ± 12.0 years; 41.8% males/58.2% females; mean body mass index 27.2 ± 4.8 kg/m²) were treated by a single surgeon using an efficient, standardized workflow for efficient direct anterior approach THA on a standard operating table. There were no differences in inclusion criteria between both groups. From this cohort, 16 simultaneous bilateral THAs and 34 unilateral THAs were prospectively compared for cost-effectiveness using detailed timestamp measurements and data on personnel and material usage. Outcome was assessed based on complication and reoperation rate and patient-reported outcome measures.

Results

There was a complication rate of 1.2%, without a difference between patients who underwent a simultaneous THA vs those who underwent a staged primary THA (5/446; 1.1% vs 3/238; 1.3% P = .386). The mean OR time (patient in/out and turnover time) was 109.4 ± 19.8 minutes for bilateral THAs and 133.8 ± 12.8 minutes for 2 unilateral THAs (P < .001). An 18% time-saving and 14% cost-saving was achieved per procedure. Sharing 5% of the cost-saving with the surgeon brings benefit to both the hospital and surgeon.

Conclusions

Implementing OR efficiency improves cost-effectiveness of simultaneous bilateral THA compared to unilateral procedures. A new value-sharing model could be a solution to align incentives.

Impact of capsular preservation on patient-reported outcomes and complication rates in total hip arthroplasty using the direct anterior approach

AIMS

It is not known whether preservation of the capsule of the hip positively affects patient-reported outcome measures (PROMs) in total hip arthroplasty using the direct anterior approach (DAA-THA). A recent randomized controlled trial found no clinically significant difference at one year postoperatively. This study aimed to determine whether preservation of the anterolateral capsule and anatomical closure improve the outcome and revision rate, when compared with resection of the anterolateral capsule, at two years postoperatively.

METHODS

Two consecutive groups of patients whose operations were performed by the senior author were compared. The anterolateral capsule was resected in the first group of 430 patients between January 2012 and December 2014, and preserved and anatomically closed in the second group of 450 patients between July 2015 and December 2017. There were no other technical changes between the two groups. Patient characteristics, the Charlson Comorbidity Index (CCI), and surgical data were collected from our database. PROM questionnaires, consisting of the Oxford Hip Score (OHS) and Core Outcome Measures Index (COMI-Hip), were collected two years postoperatively. Data were analyzed with generalized multiple regression analysis.

RESULTS

The characteristics, CCI, operating time, and length of stay were similar in both groups. There was significantly less blood loss in the capsular preservation group (p = 0.037). The revision rate (n = 3, (0.6%) in the resected group, and 1 (0.2%) in the preserved group) did not differ significantly (p = 0.295). Once adjusted for demographic and surgical factors, the preserved group had significantly worse PROMs: + 0.24 COMI-Hip (p < 0.001) and -1.6 OHS points (p = 0.017). However, the effect sizes were much smaller than the minimal clinically important differences (MCIDs) of 0.95 and 5, respectively). The date of surgery (influencing, for instance, the surgeon's age) was not a significant factor.

CONCLUSION

Based on the MCID, the lower PROMs in the capsular preservation group do not seem to have clinical relevance. They do not, however, confirm the expected benefit of capsular preservation reported for the posterolateral approach. Cite this article: Bone Joint J 2022;104-B(7):826-832.

Does Surgical Approach Influence the Natural History of the Unstable Total Hip Arthroplasty?

BACKGROUND

Dislocation following total hip arthroplasty (THA) is a significant complication that occurs in 0.3%-10% of cases with 13%-42% of patients requiring revision surgery. The literature has primarily focused on the dislocation risk associated with different surgical approaches. However, little is known about the natural history of the dislocated hip and whether surgical approach of the index THA is associated with further instability and revision surgery.

METHODS

This is a retrospective, single-center, multi-surgeon consecutive case series of all patients who experienced THA dislocation from 2002 to 2020. Patients were excluded if the initial dislocation was secondary to infection or fracture. The natural history of the cohort as per approach was determined. Outcome measurements of interest were the number of dislocations; the treatment surrounding each dislocation; the necessity and type of revision; and the complications encountered.

RESULTS

Of the 75 patients, 58 (77%) dislocated within 6 months following primary THA. The anterior group had greater odds of dislocation within 2 weeks post-THA compared to the lateral and posterior groups (P = .04). The mean number of dislocations per patient was significantly lower in the anterior (1.5 ± 0.7) compared to the lateral (2.4 ± 1.2) and posterior (2.1 ± 1.0) groups (P = .02). Revision surgery was needed in 30% (6/20) of patients in the anterior, 69% (25/36) of the posterior, and 68% (13/19) of the lateral groups (P = .01).

CONCLUSION

This study illustrates that while primary THA dislocations happen earlier with the anterior approach, they are typically less complicated and have a lower risk of recurrent instability and revision surgery.

The direct anterior approach to the hip: a useful tool in experienced hands or just another approach?

The direct anterior approach (DAA) to the hip was initially described in the nineteenth century and has been used sporadically for total hip arthroplasty (THA). However, recent increased interest in tissue-sparing and small incision arthroplasty has given rise to a sharp increase in the utilization of the DAA. Although some previous studies claimed that this approach results in less muscle damage and pain as well as rapid recovery, a paucity in the literature exists to conclusively support these claims. While the DAA may be comparable to other THA approaches, no evidence to date shows improved long-term outcomes for patients compared to other surgical approaches for THA. However, the advent of new surgical instruments and tables designed specifically for use with the DAA has made the approach more feasible for surgeons. In addition, the capacity to utilize fluoroscopy intraoperatively for component positioning is a valuable asset to the approach and can be of particular benefit for surgeons during their learning curve. An understanding of its limitations and challenges is vital for the safe employment of this technique. This review summarizes the pearls and pitfalls of the DAA for THA in order to improve the understanding of this surgical technique for hip replacement surgeons.

An Anatomic Study of the Relationship Between the Iliocapsularis Muscle and Iliofemoral Ligament in Total Hip Arthroplasty

Background

The preservation of soft tissues is an important factor for preventing dislocation after total hip arthroplasty. Anatomical studies have revealed that the inferior iliofemoral ligament (ILFL) contributes significantly to the native stability of the hip. This study aimed to investigate the anatomical structures of the iliocapsularis muscle (ICM) and ILFL from a surgical perspective.

Methods

In total, we assessed 50 hip specimens from 25 embalmed cadavers. The size and location of ICM and ILFL (at the upper, middle, and lower parts of the femoral head) were assessed in a neutral position. The ratio of ICM and ILFL widths to the femoral head was evaluated.

Results

The mean ICM and ILFL widths were 7.5 and 14.6, 12.0 and 14.2, and 12.8 and 15.2 mm at the upper, middle, and lower levels, respectively. The mean ICM thicknesses were 1.3, 9.0, and 9.1 mm at the upper, middle, and lower levels, respectively. The distributions of ICM and ILFL from the lateral edge of the femoral head were 21.1%–37.4% and 4.9%–36.5%, 9.5%–35.6% and 7.9%–38.7%, and 11.0%–38.7% and 9.5%–42.4% at the upper, middle, and lower levels, respectively.

Conclusion

ICM and ILFL were located at the anterolateral side of the femoral head, and the medial edge of the ILFL corresponded to that of the ICM. ICM can serve as a landmark for preserving ILFL in total hip arthroplasty using the anterior approach.

Capsular Management in Direct Anterior Total Hip Arthroplasty: A Randomized, Single-Blind, Controlled Trial

BACKGROUND

The direct anterior approach (DAA) is a popular approach to total hip arthroplasty (THA). Unlike the posterior approach, the importance of anterior capsular management is unknown. This randomized controlled trial compares capsular repair versus capsulectomy.

METHODS

This single-surgeon, single-blinded, parallel-group randomized controlled trial occurred between 2013 and 2016. Patients undergoing unilateral, primary THA for osteoarthritis consented to undergo blinded, simple randomization to anterior capsulotomy with repair or anterior capsulectomy. Primary outcome measures included hip range of motion, hip flexion strength, and pain with seated hip flexion. Secondary outcome measures included surgical time, estimated blood loss, postoperative complications, and hip disability and osteoarthritis outcome score. Data were prospectively collected intraoperatively, six weeks, six months, an average of over 5 years postoperatively.

RESULTS

Ninety-eight patients were ultimately enrolled in the trial; 50 received capsulectomy and 48 received capsulotomy. No significant differences were seen in preoperative demographics or in primary or secondary outcomes during this study. No difference was seen in pain at final follow-up at average > 5 years postoperatively.

CONCLUSION

This study demonstrates that capsular management in DAA THA does not affect postoperative pain or range of motion. The anterior capsule's role in prosthetic stability after DAA THA remains uncertain, but it does not currently appear that repair provides benefit and may lead to increased surgical time and blood loss. As such, capsular management in DAA THA is at surgeon discretion.