Bikini anterior hip replacements in obese patients are not associated with an increased risk of complication

Body Mass Index Above 35 Has Increased Risk of Complications but Still Achieves Clinically Meaningful Improvement in Patient-Reported Outcomes After Anterior-Based Total Hip Arthroplasty

Background

Increased perioperative complications in obese patients undergoing total hip arthroplasty (THA) have previously been reported. There is a relative paucity of data evaluating these complications strictly in the context of anterior-based THA. In this study, we compare the outcomes following anterior-based THA as a function of body mass index (BMI).

Methods

A 1:1 matched retrospective cohort study was conducted. Patients undergoing anterior-based THA from January 2022 to June 2024 with a BMI >35 kg/m2 were matched 1:1 based on age and sex to patients with a BMI <35 kg/m2 from our division registry. Demographic data, surgical details, complications (intraoperative and postoperative), and patient-reported outcome measures (PROMs: 12-Item Short Form P/M, Western Ontario and McMaster Universities Osteoarthritis Index-P/S/F) were collected and analyzed.

Results

There were 280 patients included (140 per group). There were 27 postoperative complications in the BMI >35 kg/m2 group and 10 in the BMI <35 kg/m2 group (P < .01). There were 10 major complications (4 dislocations, 2 periprosthetic fractures, and 4 deep infections requiring incision and drainage) in the BMI over 35 kg/m2 group, with no major complications occurring in the lower BMI group. There were 3 intraoperative complications (periprosthetic fracture), all in patients with BMI >35 kg/m2. There was significant improvement in Western Ontario and McMaster Universities Osteoarthritis Index P/S/F scores and 12-Item Short Form pain in both groups at 3 months postoperatively, with greater improvements seen in the BMI >35 kg/m2 group.

Conclusions

The present study found that despite significant differences in postoperative complications, there were significant improvements in PROMs in patients with a BMI above and below 35 kg/m2 who underwent anterior THA.

A Systematic Review and Meta-Analysis of Periprosthetic Joint Infection Rates in Morbidly Obese Patients Undergoing Total Hip Arthroplasty

INTRODUCTION

Periprosthetic joint infection (PJI) is a severe complication associated with higher rates in obese individuals after total hip arthroplasty (THA). Hard cutoffs for body mass index (BMI) levels may lead to restricted access to care; however, a certain level of obesity may warrant these restrictions for patient safety. The purpose of this study was to perform a systematic review and meta-analysis of articles comparing PJI rates in morbidly versus nonmorbidly obese patients undergoing primary THA.

METHODS

A systematic search of PubMed, EMBASE, Cochrane, and Google Scholar databases was conducted following Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Original studies comparing PJI rates in morbidly obese (BMI ≥40 kg/m2) and nonobese (BMI <40 kg/m2) THA patients were included. Data extraction, bias assessment, and quantitative synthesis were done.

RESULTS

After exclusion criteria, 10 studies comprising 46,080 THAs were included. Morbidly obese patients were found to have markedly higher rates of PJI compared with nonmorbidly obese patients (odds ratio = 4.332, 95% confidence interval [CI], 2.943 to 6.375, I2 = 0, P-value = 0.901). Analysis of cohorts stratified by BMI showed consistent trends; morbidly obese patients demonstrated markedly increased risk of blood transfusions, postoperative fractures, superficial infections, dislocations, readmission within 90 days, surgical complications, and revision surgery.

CONCLUSION

Morbidly obese patients demonstrate markedly increased risk of PJI and other complications after primary THA. This should be discussed with patients to safely provide the option of THA while minimizing restrictions on access to care.

For many but not for all: the bikini incision direct anterior approach for total hip arthroplasty. A narrative review

Total hip arthroplasty (THA) has significantly improved the lives of patients with degenerative hip disorders. The direct anterior approach (DAA) is favored for its minimally invasive nature, leading to less postoperative pain and a faster recovery. The bikini incision (BI) approach was developed to enhance aesthetic outcomes while maintaining the clinical and functional benefits of the DAA. Despite its advantages, the BI technique presents challenges, controversies persist regarding its efficacy and safety, and there is no consensus within the medical community about its overall benefits. Incisions aligned with Langer's lines, like the BI, promote better healing and minimal scarring. Studies indicate that BI patients report higher satisfaction with scar appearance and texture compared to traditional DAA patients. However, the BI carries a higher risk of lateral femoral cutaneous nerve (LFCN) injury, although most symptoms resolve within 6 months. For obese patients, the BI is associated with fewer complications, such as infections and delayed healing, compared to the conventional DAA, making it a safe and effective option. BI patients also experience better aesthetic outcomes and functional recovery, with reduced pain and itching. The BI technique in THA represents a significant advancement, offering improved aesthetic and wound-healing outcomes. The shift from the traditional DAA to the BI aligns with patient preferences for scars that are less visible and conspicuous. Despite the steep learning curve and risks, careful patient selection and refined surgical techniques can enhance the BI's benefits. Future research should focus on long-term outcomes and comparative studies to further establish the BI's efficacy and safety. As patient demand for aesthetically favorable surgeries grows, the BI is likely to become a preferred approach in THA.

Surgical Approach and Body Mass Index Impact Risk of Wound Complications Following Total Hip Arthroplasty

BACKGROUND

Previous studies have suggested that wound complications may differ by surgical approach after total hip arthroplasty (THA), with particular attention toward the direct anterior approach (DAA). However, there is a paucity of data documenting wound complication rates by surgical approach and the impact of concomitant patient factors, namely body mass index (BMI). This investigation sought to determine the rates of wound complications by surgical approach and identify BMI thresholds that portend differential risk.

METHODS

This multicenter study retrospectively evaluated all primary THA patients from 2010 to 2023. Patients were classified by skin incision as having a laterally based approach (posterior or lateral approach) or DAA (longitudinal incision). We identified 17,111 patients who had 11,585 laterally based (68%) and 5,526 (32%) DAA THAs. The mean age was 65 years (range, 18 to 100), 8,945 patients (52%) were women, and the mean BMI was 30 (range, 14 to 79). Logistic regression and cut-point analyses were performed to identify an optimal BMI cutoff, overall and by approach, with respect to the risk of wound complications at 90 days.

RESULTS

The 90-day risk of wound complications was higher in the DAA group versus the laterally based group, with an absolute risk of 3.6% versus 2.6% and a multivariable adjusted odds ratio of 1.5 (P < .001). Cut-point analyses demonstrated that the risk of wound complications increased steadily for both approaches, but most markedly above a BMI of 33.

CONCLUSIONS

Wound complications were higher after longitudinal incision DAA THA compared to laterally based approaches, with a 1% higher absolute risk and an adjusted odds ratio of 1.5. Furthermore, BMI was an independent risk factor for wound complications regardless of surgical approach, with an optimal cut-point BMI of 33 for both approaches. These data can be used by surgeons to help consider the risks and benefits of approach selection.

LEVEL OF EVIDENCE

Level III.

Vertical or Horizontal (Bikini) Incision for Direct Anterior Total Hip Arthroplasty: Outcomes of Early (<90 day) Revision

BACKGROUND

The horizontal 'bikini' incision for direct anterior approach (DAA) total hip arthroplasty has gained popularity due to its early wound healing characteristics; however, the nonextensile nature of this approach may pose problems in treating early complications. This study sought to characterize the outcomes of early revision (<90 days) in patients who underwent anterior hip arthroplasty utilizing either a traditional longitudinal incision or a horizontal (bikini) incision.

METHODS

This retrospective study identified patients who underwent DAA primary total hip arthroplasty with a subsequent DAA revision within 90 days. Patients were divided into two cohorts based on the orientation of their incision: either 'longitudinal incision' (in accordance with the Smith Peterson interval) or 'horizontal bikini incision' (in accordance with the hip flexion crease).

RESULTS

There were 74 patients who underwent DAA revision arthroplasty within 90 days of primary arthroplasty; 65 had a longitudinal incision, and 9 had a horizontal (bikini) incision. In the longitudinal incision group, 2 patients (3.1%) required plastic surgery closure, and 11 patients (16.9%) required additional operations. Of the 9 bikini incision patients, 6 patients required the assistance of plastic surgery closure, and 7 patients required multiple orthopaedic operations.

CONCLUSIONS

Our study suggests that a horizontal bikini incision is less forgiving in the early postoperative period if a more extensile exposure is needed for revision surgery, as measured by the need for plastic surgery and additional returns to the operating room. In our cohort, the longitudinal incision allowed for the management of early surgical complications with less morbidity.

Comparison of postoperative outcomes between endoscopy assisted minimal invasive direct anterior approach and bikini direct anterior approach in total hip arthroplasty

BACKGROUND

We have innovatively developed a modified bikini direct anterior approach total hip arthroplasty (THA), endoscopy assisted minimal invasive direct anterior approach (Endo-DAA). The study compared aesthetic appearance of the scar, postoperative radiographic and functional outcomes, and complications of Endo-DAA with Bikini-DAA.

METHODS

Patients who underwent primary THA using Endo-DAA or Bikini-DAA were included. The main innovation of Endo-DAA is the use of minimally invasive 5-7 cm proximal transverse incision and distal puncture with an endoscopy assisted split-type tool to complete the acetabular preparation and prosthesis implantation. Outcomes evaluated included evaluation of scar satisfaction, hip reconstruction including inclination, anteversion and leg-length discrepancy (LLD) and patient-reported outcomes including Harris Hip Scores (HHS) and Forgotten Joint Score (FJS). Follow-up time points included preoperative, 6 weeks, 6 months and 12 months.

RESULTS

Finally, 195 hips in Endo-DAA and 207 hips in Bikini DAA completed the follow-up. The Endo-DAA group was superior to the Bikini-DAA group in the cosmetic aspects of scars. the cup anteversion angle of Endo-DAA group was significantly better than that in the Bikini-DAA group. The early HHS and FJS of the Endo-DAA group were superior to those of the Bikini-group. Operation time, blood loss, incision length, length of stay and duration to start no-assistive-device walking were also significantly better in the Endo-DAA group. Furthermore, the Bikini-DAA group had a higher incidence of complication.

CONCLUSION

Compared with Bikini-incision, Endo-DAA improves patients' subjective satisfaction with scar aesthetics, accelerates rapid recovery of postoperative function, and reduces postoperative complications.

Impact of wound complications in obese versus non-obese patients undergoing total hip arthroplasty: A meta-analysis

This meta-analysis examined the post-operative wound effect of both obese and non-obese in total hip arthroplasty (THA) patients. To gather as complete an overview as possible, the researchers took advantage of 4 databases-PubMed, Embase, Cochrane Library and Web of Science-to conduct a critical assessment. Following the development of inclusion and exclusion criteria, the researchers evaluated the quality of each document. A total of 9 related trials were conducted to determine the 95% CI (CI) and OR using a fixed-effect model. The final meta-analyses were conducted with RevMan 5.3. Our findings indicate that there is no statistically significant benefit in terms of post-operative wound complications among obese and non-obese patients. Obese subjects had a significantly higher risk of injury than those without obesity (OR, 1.43; 95% CI, 1.04, 1.95, p = 0.03); obesity was also associated with a significantly higher risk of operative site infection than in non-obese subjects (OR, 1.96; 95% CI, 1.76, 2.18, p < 0.0001); and after surgery, there was also a significant increase in the risk of post-operative wound infections among obese subjects than in non-obese subjects (OR, 1.57; 95% CI, 1.34, 1.84, p < 0.0001). However, due to the small size of the cohort study in this meta-study, caution is required in the analysis. More randomized, controlled studies will be needed to validate these results.

Is the Direct Anterior Approach for Total Hip Arthroplasty Effective in Obese Patients? Early Clinical and Radiographic Results from a Retrospective Comparative Study

Background and objectives: Total hip arthroplasty (THA) in obese patients (BMI > 30) is considered technically demanding, and it is associated with higher rates of general and specific complications including infections, component malpositioning, dislocation, and periprosthetic fractures. Classically, the Direct Anterior Approach (DAA) has been considered less suitable for performing THA surgery in the obese patient, but recent evidence produced by high-volume DAA THA surgeons suggests that DAA is suitable and effective in obese patients. At the authors' institution, DAA is currently the preferred approach for primary and revision THA surgery, accounting for over 90% of hip surgeries without specific patient selection. Therefore, the aim of the current study is to evaluate any difference in early clinical outcomes, perioperative complications, and implant positioning after primary THAs performed via DAA in patients who were divided according to BMI. Material and methods: This study is a retrospective review of 293 THA implants in 277 patients that were performed via DAA from 1 January 2016 to 20 May 2020. Patients were further divided according to BMI: 96 patients were normal weight (NW), 115 were overweight (OW), and 82 were obese (OB). All the procedures were performed by three expert surgeons. The mean follow-up was 6 months. Patients' data, American Society of Anesthesiologists (ASA) score, surgical time, days in rehab unit, pain at the second post-operative day recorded by using a Numerical Rating Scale (NRS), and number of blood transfusions were recorded from clinical charts and compared. Radiological evaluation of cup inclination and stem alignment was conducted on post-operative radiographs; intra- and post-operative complications at latest follow-up were recorded. Results: The average age at surgery of OB patients was significantly lower compared to NW and OW patients. The ASA score was significantly higher in OB patients compared to NW patients. Surgical time was slightly but significantly higher in OB patients (85 ± 21 min) compared to NW (79 ± 20 min, p = 0.05) and OW patients (79 ± 20 min, p = 0.029). Rehab unit discharge occurred significantly later for OB patients, averaging 8 ± 2 days compared to NW patients (7 ± 2 days, p = 0.012) and OW patients (7 ± 2 days; p = 0.032). No differences in the rate of early infections, number of blood transfusions, NRS pain at the second post-operative day, and day of post-operative stair climbing were found among the three groups. Acetabular cup inclination and stem alignment were similar among the three groups. The perioperative complication rate was 2.3%; that is, perioperative complication occurred in 7 out of 293 patients, with a significantly higher incidence of surgical revisions required in obese patients compared to the others. In fact, OB patients showed a higher revision rate (4.87%) compared to other groups, with 1.04% for NW and 0% for OW (p = 0.028, Chi-square test). Causes for revision in obese patients were aseptic loosening (2), dislocation (1), and clinically significant post-operative leg length discrepancy (1), with a revision rate of 4/82 (4.87%) during follow-up. Conclusions: THA performed via DAA in obese patients could be a solid choice of treatment, given the relatively low rate of complications and the satisfying clinical outcomes. However, surgical expertise on DAA and adequate instrumentation for this approach are required to optimise the outcomes.