Total hip arthroplasty outcomes in morbidly obese patients: A systematic review

Body Mass Index Does Not Drive the Risk for Early Postoperative Instability After Total Hip Arthroplasty: A Matched Cohort Analysis

BACKGROUND

Instability remains the leading cause of revision following total hip arthroplasty (THA). The objective of the present investigation was to determine whether an elevated body mass index (BMI) is associated with an increased risk of instability after primary THA.

METHODS

An administrative claims database was queried for patients undergoing elective, primary THA for osteoarthritis between 2010 and 2022. Patients who underwent THA for a femoral neck fracture were excluded. Patients who had an elevated BMI were grouped into the following cohorts: 25 to 29.9 (n = 2,313), 30 to 34.9 (n = 2,230), 35 to 39.9 (n = 1,852), 40 to 44.9 (n = 1,450), 45 to 49.9 (n = 752), and 50 to 59.9 (n = 334). Patients were matched 1:1 based on age, sex, and Elixhauser Comorbidity Index, as well as a history of spinal fusion, neurodegenerative disorders, and alcohol abuse, to controls with a normal BMI (20 to 24.9). A multivariate logistic regression controlling for age, sex, Elixhauser Comorbidity Index, and additional risk factors for dislocation was used to evaluate dislocation rates at 30 days, 90 days, 6 months, 1 year, and 2 years. Rates of revision for instability were similarly compared at 1 year and 2 years postoperatively.

RESULTS

No significant differences in dislocation rate were observed between control patients and each of the evaluated BMI classes at all evaluated postoperative intervals (all P values > .05). Similarly, the risk of revision for instability was comparable between the normal weight cohort and each evaluated BMI class at 1 year and 2 years postoperatively (all P values > .05).

CONCLUSIONS

Controlling for comorbidities and known risk factors for instability, the present analysis demonstrated no difference in rates of dislocation or revision for instability between normal-weight patients and those in higher BMI classes.

Infiltration of local anesthetic in the Interspace between the popliteal artery and capsule of the posterior knee "IPACK block" versus adductor canal block "ACB" for pain relief after open wedge high tibial osteotomy: a randomized clinical trial

BACKGROUND

A high tibial osteotomy is usually associated with severe postoperative pain. Both adductor canal block (ACB) and interspace between the popliteal artery and capsule of the posterior knee (IPACK) have been described as effective block techniques for providing analgesia after knee surgeries, with few comparisons in wedge osteotomy cases. We aim to compare the postoperative analgesic profile of the previously mentioned two block techniques in patients undergoing tibial osteotomies.

METHODS

Sixty patients were enrolled in this randomized prospective trial (30 received IPACK and 30 received ACB). Both blocks were installed before the spinal anesthesia after infiltration of 2 mL lidocaine 2%. Twenty mL of bupivacaine 0.25% mixed with dexamethasone as anesthetic adjuvant were used for both blocks. The postoperative analgesic profiles were compared between the two groups.

RESULTS

Postoperative pain scores were lower in the IPACK group, and that decrease was evident throughout the first 10 hours postoperatively. Additionally, the duration of analgesia was much prolonged with the same block (487.50±82.39 vs. 301.93±92.06 minutes with ACB). There was a significant decline in postoperative analgesic consumption (1.27±0.45 vs. 1.8±0.61 gm, P=0.000), and a significant increase in the ambulation distance (19.10±0.60 vs. 17.73±0.45 m, P=0.000) with a significant decline in the duration of hospitalization (43.27±7.61 vs. 54±8.35 hours) in the IPACK group compared to the ACB group.

CONCLUSIONS

IPACK is a superior block technique compared to ACB in patients undergoing high tibial osteotomy regarding postoperative analgesia, ambulation distance, and patient satisfaction with little rate of adverse events in both groups.

How Has the Total Hip Arthroplasty Patient Population Changed? A Ten-Year Analysis of Total Hip Arthroplasty Patients From 2013 to 2022: A Retrospective, Single-Center Study

BACKGROUND

Over the past decades, utilization of total hip arthroplasty (THA) has steadily increased. Understanding the demographic trends of THA patients can assist in projecting access to care. This study sought to assess the temporal trends in THA patient baseline characteristics and socioeconomic factors.

METHODS

We retrospectively analyzed 16,296 patients who underwent primary elective THA from January 1, 2013, to December 31, 2022. Demographic data, including age, sex, race, body mass index (BMI), Charlson comorbidity index, insurance, and socioeconomic status, as determined by median income by patients' zip code, were collected. The trends of these data were analyzed using the Mann-Kendall test.

RESULTS

Over the past decade at our institution, patient age (2013: 62.1 years to 2022: 65.1 years, P = .001), BMI (2013: 29.0 to 2022: 29.5, P = .020), and mean Charlson comorbidity index (2013: 2.4 to 2022: 3.1, P = .001) increased. The proportion of Medicare patients increased from 48.4% in 2013 to 54.9% in 2022 (P = .001). The proportion of African American patients among the THA population increased from 11.3% in 2013 to 13.0% in 2022 (P = .012). Over this period, 90-day readmission and 1-year revision rates did not significantly change (2013: 4.8 and 3.0% to 2022: 3.4 and 1.4%, P = .107 and P = .136, respectively). The proportion of operations using robotic devices also significantly increased (2013: 0% to 2022: 19.1%; P < .001).

CONCLUSIONS

In the past decade, the average age, BMI, and comorbidity burden of THA patients have significantly increased, suggesting improved access to care for these populations. Similarly, there have been improvements in access to care for African American patients. Along with these changes in patient demographics, we found no change in 90-day readmission or 1-year revision rates. Continued characterization of the THA patient population is vital to understanding this demographic shift and educating future strategies and improvements in patient care.

Short stem hip arthroplasty with the optimys prosthesis is a safe and effective option for obese patients: a mid-term follow-up multicenter study

INTRODUCTION

Short stems are a valuable option in young patients undergoing total hip arthroplasty (THA) because of their bone stock preserving properties facilitating revision hip arthroplasty. Although the effect of obesity on conventional THA is well studied, data about short stem THA in obese patients are lacking. Therefore, this study aimed to investigate the influence of obesity on complications, revisions, and outcome after short stem THA.

MATERIALS AND METHODS

This multicenter, observational cohort study included patients undergoing short stem THA with the optimys prosthesis. Follow-up examinations were performed at specific intervals up to 7 years postoperatively. Operation characteristics, general and specific complications, revisions, VAS rest pain, VAS load pain, VAS patient satisfaction, and Harris Hip Score (HHS) were recorded and statistically compared between obese (BMI ≥ 30 kg/m2) and non-obese (BMI < 30 kg/m2) patients.

RESULTS

Of the 224 patients included with a mean follow-up of 87.2 months (range 81.9-104.0), 69 were assigned to the OB group and 155 to the non-OB group. A minimally invasive approach was significantly less often selected in obese patients (p = 0.049), whereas operating time and length of hospital stay were not significantly different. The rate of general and specific complications did not significantly differ between both groups. Survival of the optimys prosthesis was 99.1% at 7-year follow-up and one patient per group had to undergo revision surgery. VAS rest pain, load pain, and satisfaction improved from preoperatively to postoperatively in both groups without a significant difference between both groups. While the HHS was improved from preoperatively to postoperatively, obese patients showed a significantly lower HHS at the 7-year follow-up (p = 0.01) but still exhibited an excellent scoring above the PASS threshold.

CONCLUSION

Short stem THA with the optimys prosthesis is a safe and effective option also in obese patients with an excellent clinical outcome and a low complication rate.

The Impact of Obesity on Total Hip Arthroplasty Outcomes When Performed by High-Volume Surgeons-A Propensity Matched Analysis From a High-Volume Urban Center

BACKGROUND

Previous data suggest that obesity does not impact surgical outcomes following total knee arthroplasty performed by high-volume (HV) surgeons. However, this effect has yet to be studied in total hip arthroplasty (THA) patients. This study aimed to evaluate the impact of patient obesity on THA outcomes when surgery is performed by HV surgeons.

METHODS

A retrospective analysis of patients who underwent primary, elective THA between January 2012 and December 2022 with a HV surgeon (top 25% of surgeons by number of annual primary THA) was performed. Patients were stratified by their body mass index (BMI) into 3 cohorts: BMI ≥ 40 (morbidly obese [MO]), 30 ≤ BMI < 40 (obese), and BMI < 30 (nonobese); and 1:1:1 propensity matched based on baseline characteristics. A total of 13,223 patients were evaluated, of which 669 patients were included in the final matched analysis (223 patients per group). The average number of annual THAs performed for HV surgeons was 171 cases.

RESULTS

The MO patients had significantly longer surgical times (P < .001) and hospital lengths of stay (P < .001). Rates of 90-day readmissions (P = .211) and all-cause, septic, and aseptic revisions at the latest follow-up (P = .268, P = .903, and P = .168, respectively) were comparable between groups. In a subanalysis for non-HV surgeons, MO patients had a significantly greater risk of revision (P = .021) and trended toward significantly greater readmissions (P = .056).

CONCLUSIONS

Clinical outcomes and complication rates after THA performed by a HV surgeon are similar regardless of patient obesity status. Patients who have MO may experience improved outcomes and reduced procedural risks if they are referred to HV surgeons.

LEVEL OF EVIDENCE

III.

Does Body Mass Index (BMI) Affect the Reconstruction of Biomechanical Parameters in Patients Undergoing Total Hip Replacement (THR) through the Direct Anterior Approach (DAA)?

OBJECTIVE

Direct anterior approach total hip replacement (DAA-THR) is gaining increased interest due to its tissue-sparing nature and rapid recovery. Obesity has been shown to be a significant parameter influencing cup positioning in DAA-THR. It was the intention of this retrospective study to examine how obesity would influence the restoration of native hip biomechanical parameters during DAA-THR.

MATERIALS AND METHODS

A total of 74 patients from a high-volume university orthopedic center after unilateral DAA-THA were included. Patients were retrospectively allocated to a study group (BMI > 30 kg/m2) and a control group (BMI < 30 kg/m2). Furthermore, propensity-score matching for baseline parameters was performed, leaving 30 patients in each group. Biomechanical parameters of the hip (i.e., femoral offset (FO), abductor lever arm (ABL), acetabular offset (AO), center of rotation (COR), stem alignment (SA), body weight lever arm (BWL), cup inclination (CI), and leg length discrepancy (LLD) were evaluated on standardized plain radiographs, and parameters were compared to the native contralateral hip.

RESULTS

Mean BMI in the study group was 35.07 ± 5.13 kg/m2 and 25.43 ± 2.64 kg/m2 in the control group. There was a significant decrease of the ABL only in the study cohort (p = 0.01). CI and SA did not differ between both cohorts. FO was slightly increased compared to the native hip in both groups. There was a marginally higher but non-significant proportion of improper FO restoration in the study group (19 vs. 16 patients, p = 0.60).

CONCLUSIONS

Obesity, as quantified by BMI, only has a limited impact on the adequate reconstruction of native biomechanical parameters of the hip during DAA-THR. ABL was the only parameter to be significantly decreased in the overweight patients after DAA-THR. Therefore, special care should be taken on proper acetabular reaming and consequent seating of the cup in the obese patient to avoid excessive lateral positioning.

Short-term outcomes of thin highly cross-linked polyethylene liners in primary total hip arthroplasty

INTRODUCTION

The use of thin highly cross-linked polyethylene (HXLPE) liners in total hip arthroplasty (THA) allows utilisation of larger femoral heads. However, concern surrounding postoperative complications remains. This study aims to investigate rates of revision and re-admission associated with thin HXLPE liners at short-term follow-up.

METHODS

We retrospectively reviewed 3047 patients who underwent THA with a cementless modular acetabular implant with a 36-mm femoral head, and different thicknesses of HXPLE liners from 2011 to 2021. We identified 723 patients (23.7%) with a minimum 2-year follow-up and 206 patients (6.8%) with a minimum 5-year follow-up. Patients in the thin group (TG, n = 1020) received <5.1-mm liners with 52-mm size cups while patients in the non-thin group (NTG, n = 2027) received >5.1-mm liners with >52-mm size cups. Outcomes were compared using multi-variable logistic regressions while controlling for all significant demographic differences.

RESULTS

We found no significant differences in re-admission (3.9% vs. 4.3%, OR 0.97; 95% CI, 0.63-1.49; p = 0.874) and revision (2.5% vs. 3.2%, OR 0.72; 95% CI, 0.41-1.26; p = 0.246) rates between groups. The difference in fracture rate between groups was not significant, but the 1 recorded acetabular fracture (5%) occurred in the NTG. Although the rate of liner exchange was lower in the TG (1.1%) compared to the NTG (2.3%), the difference was not statistically significant (OR 0.51; 95% CI, 0.24-1.05; p = 0.068). Liners were exchanged for liner wear in 1 hip (1%), aseptic reasons in 38 hips (66%), and peri-prosthetic joint infection in 19 hips (33%).

CONCLUSIONS

Patients undergoing THA with a thin liner were not significantly predisposed to higher rates of revision surgery or poorer clinical outcomes at short-term follow-up when compared to those who received a thicker liner. Consequently, further long-term studies regarding the utility of thin HXLPE implants in reducing complications should be pursued.

Body Mass Index (BMI) Cutoffs and Racial, Ethnic, Sex, or Age Disparities in Patients Treated With Total Ankle Arthroplasty

Background

The rising prevalence of obesity among American adults has disproportionately affected Black adults and women. Furthermore, body mass index (BMI) has historically been used as a relative contraindication to many total joint arthroplasty (TJA) procedures, including total ankle arthroplasty. The purpose of this study was to investigate potential disparities in patient eligibility for total ankle arthroplasty based on race, ethnicity, sex, and age by applying commonly used BMI cutoffs to the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database.

Methods

Patients in the ACS-NSQIP database who underwent TAA from 2011 to 2020 were retrospectively reviewed in a cross-sectional analysis. BMI cutoffs of <50, <45, <40, and <35 were then applied. The eligibility rate for TAA was examined for each BMI cutoff, and findings were stratified by race, ethnicity, sex, and age. Independent t tests, chi-squared tests, and Fisher exact tests were performed to compare differences at an α = 0.05.

Results

A total of 1215 of 1865 TAA patients (65.1%) were included after applying the exclusion criteria. Black patients had disproportionately lower rates of eligibility at the most stringent BMI cutoff of <35 (P = .004). Hispanic patients had generally lower rates of eligibility across all BMI cutoffs. In contrast, Asian American and Pacific Islander patients had higher rates of eligibility at the BMI cutoffs of <35 (P = .033) and <40 (P = .039), and White non-Hispanic patients had higher rates of eligibility across all BMI cutoffs. Females had lower eligibility rates across all BMI cutoffs. Ineligible patients were also younger compared to eligible patients across all BMI cutoffs.

Conclusion

Stringent BMI cutoffs may disproportionately disqualify Black, female, and younger patients from receiving total ankle arthroplasty.

Level of Evidence

Level III, retrospective cross-sectional study.

Risk Factors for Failure of Total Ankle Replacements: A Data Linkage Study Using the National Joint Registry and NHS Digital

BACKGROUND

Despite the increasing numbers of ankle replacements, there remains debate about which patients should undergo an ankle replacement, and there are limited studies analyzing risk factors for failure of an ankle replacement. The primary aim of this study is to analyze the risk factors for failure of total ankle replacements.

METHODS

A data linkage study combining the National Joint Registry (NJR) Data and NHS (National Health Service) Digital data was performed. The primary outcome of failure is defined as the removal or exchange of any components of the implanted device. Kaplan-Meier survival charts were used to illustrate survivorship. Multivariable Cox proportional hazards regression models were fitted to analyze potential risk factors for failures or ankle replacements.

RESULTS

The overall 5-year survival was 90.2% (95% CI 89.2%-91.1%). In multivariable (adjusted) Cox regression models, only age (hazard ratio [HR] 0.96, 95% CI 0.94-0.97), body mass index (BMI; HR 1.03, 95% CI 1.01-1.06), and underlying etiology (HR 0.88, 95% CI 0.80-0.97) were associated with an increased risk of failure.

CONCLUSION

This study demonstrates that younger patients and those with an increased BMI have an increased risk of failure of a primary ankle replacement. We also show that rheumatoid patients have higher survivorship than those with osteoarthritis.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Disparities in Elective and Nonelective Total Hip Arthroplasty

BACKGROUND

Prior studies have shown disparities in utilization of primary and revision total hip arthroplasty (THA). However, little is known about patient population differences associated with elective and nonelective surgery. Therefore, the aim of this study was to explore factors that influence primary utilization and revision risk of THA based on surgery indication.

METHODS

Data were obtained from 7,543 patients who had a primary THA from 2014 to 2020 in a database, which consists of multiple health partner systems in Louisiana and Texas. Of these patients, 602 patients (8%) underwent nonelective THA. THA was classified as "elective" or "nonelective" if the patient had a diagnosis of hip osteoarthritis or femoral neck fracture, respectively.

RESULTS

After multivariable logistic regression, nonelective THA was associated with alcohol dependence, lower body mass index (BMI), women, and increased age and number of comorbid conditions. No racial or ethnic differences were observed for the utilization of primary THA. Of the 262 patients who underwent revision surgery, patients who underwent THA for nonelective etiologies had an increased odds of revision within 3 years of primary THA (odds ratio (OR) = 1.66, 95% Confidence Interval (CI) = 1.06-2.58, P-value = .025). After multivariable logistic regression, patients who had tobacco usage (adjusted odds ratio (aOR) = 1.36, 95% CI = 1.04-1.78, P-value = .024), alcohol dependence (aOR = 2.46, 95% CI = 1.45-4.15, P-value = .001), and public insurance (OR = 2.08, 95% CI = 1.18-3.70, P-value = .026) had an increased risk of reoperation.

CONCLUSION

Demographic and social factors impact the utilization of elective and nonelective primary THA and subsequent revision surgery. Orthopaedic surgeons should focus on preoperative counseling for tobacco and alcohol cessation as these are modifiable risk factors to directly decrease reoperation risk.

Pre- and Post-Operative Rehabilitation Interventions in Patients at Risk of Poor Outcomes Following Knee or Hip Arthroplasty: Protocol for Two Systematic Reviews

Objective

Total knee (TKA) and hip arthroplasty (THA) are successful procedures in treating end-stage osteoarthritis when nonoperative treatments fail. However, a growing body of literature has been reporting suboptimal outcomes following TKA and THA. While pre- and post-operative rehabilitation is imperative to recovery, little is known about their effectiveness for patients at risk of poor outcomes. In the 2 systematic reviews with identical methodology, we aim to evaluate the effectiveness of (a) pre-operative and (b) post-operative rehabilitation interventions for patients at risk of poor outcomes following TKA and THA.

Methods

The 2 systematic reviews will follow the principles and recommendations outlined in the Cochrane Handbook. Only randomized controlled trials (RCTs) and pilot RCTs will be searched in 6 databases: CINAHL, MEDLINE, Embase, Web of Science, Pedro, and OTseeker. Eligible studies including patients at risk of poor outcomes and evaluating rehabilitation interventions following and preceding arthroplasty will be considered for inclusion. Primary outcomes will include performance-based tests and functional patient-reported outcome measures, and secondary outcomes will include health-related quality of life and pain. The quality of eligible RCTs will be evaluated using the Cochrane's risk of bias tool, and the strength of evidence will be assessed using the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE).

Discussion

These reviews will synthesize the evidence regarding the effectiveness of pre-and post-operative rehabilitation interventions for patients at risk of poor outcomes, which in turn may inform practitioners and patients in planning and implementing the most optimal rehabilitation programs to achieve the best outcomes after arthroplasty.

Systematic Review Registration

PROSPERO CRD42022355574.

Telemedicine approach for patient follow-up after total knee and reverse total shoulder arthroplasty: a pilot study

PURPOSE

The study aimed to demonstrate the reduction in postoperative follow-up visit time for patients receiving total knee arthroplasty (TKA) or reverse total shoulder arthroplasty (RTSA) by implementing a novel asynchronous telemedicine system compared to face-to-face visits. The range of motion interobserver agreement and patient satisfaction were evaluated in the telemedicine group.

METHODS

A randomized controlled trial was conducted with a total of 28 patients with a mean age of 71 years (range 13.3). Patients were distributed into two study groups, TKA (n = 14) and RTSA (n = 14), and each group was randomly allocated into a face-to-face or virtual follow-up visit group. For the virtual group, software was designed including patient-specific model items (X-ray, range of motion and functional scores) for each arthroplasty. Functional assessment was conducted using the International Knee Documentation Committee (IKDC) score for TKA and American Shoulder and Elbow score (ASES) and Simple Shoulder Test (SST) for RTSA. The range of motion interobserver concordance was conducted in the virtual follow-up groups via an intraclass correlation coefficient. Finally, a satisfaction survey was performed in the virtual follow-up groups. Mann-Whitney U test was used for statistical analysis.

RESULTS

Mean time differences between face-to-face and virtual follow-ups were 502.5 s (95% CI 387.8-617.1; p < 0.002) in the RTSA group and 710 s (95% CI 597.91-822; p < 0. 002) in the TKA group. The range of motion interobserver concordance in the virtual group was 0.974 for TKA and 0.804 for RTSA. Finally, virtual follow-up satisfaction using the telematic method was 8.9 out of 10.

CONCLUSION

The results of this study showed that a virtual follow-up using asynchronous telemedicine systems could reduce visit times, allow a correct articular range of motion evaluation and maintain satisfaction perception for patients. Asynchronous telemedicine could be an efficient method to conduct postoperative follow-up after knee and shoulder arthroplasty.

Total Hip Arthroplasty in Morbidly Obese: Does a Strict Body Mass Index Cutoff Yield Meaningful Change?

PURPOSE

The number of obese patients seeking total hip arthroplasty (THA) continues to expand despite body mass index (BMI) cutoffs. We sought to determine the outcomes of THA in the morbidly obese patient, and hypothesized they would have comparable outcomes to two cohorts of obese, and normal weight patients.

MATERIALS AND METHODS

THA performed on morbidly obese patients (BMI >40 kg/m²) at a single academic center from 2010 until 2020 were retrospectively reviewed. Eighty morbidly obese patients were identified, and matched in a 1:3:3 ratio to control cohorts with BMI 30-40 kg/m² and BMI <30 kg/m². Acute postoperative outcomes and BMI change after surgery were evaluated for clinical significance with univariate and regression analyses. Cox proportional hazard ratio was calculated to evaluate prosthetic joint infection (PJI) and revision surgery through follow-up. Mean follow-up was 3.9 years.

RESULTS

In the acute postoperative period, morbidly obese patients trended towards increased hospital length of stay, facility discharge and 90-day hospital returns. At final follow-up, a higher percentage of morbidly obese patients had clinically significant (>5%) BMI loss; however, this was not significant. Cox hazard ratio with BMI <30 kg/m² as a reference demonstrated no significant difference in survival to PJI and all-cause revision in the morbidly obese cohort.

CONCLUSION

Morbidly obese patients (BMI >40 kg/m²) require increased resource expenditure in the acute postoperative period. However, they are not inferior to the control cohorts (BMI <30 kg/m², BMI 30-40 kg/m²) in terms of PJI or all-cause revisions at mid-term follow-up.

Total knee replacements using rotating hinge implants in polio patients: clinical and functional outcomes

Little evidences are available in the literature concerning the outcomes of total knee replacement (TKR) in poliomyelitis patients with severe knee deformities or degeneration. Encouraging results have been reported concerning the use of constrained implants, i.e., rotating hinge knee prosthesis (RHK), compared to less constrained ones. The purpose of this paper is to report our experience with rotating hinge total knee replacement, using only RHK prosthesis, to determine functional results, complications, and survival of TKR in poliomyelitis patients. We performed a retrospective chart review of 14 patients with a history of knee osteoarthritis following poliomyelitis that underwent primary TKR, for a total of 15 surgical procedure (one bilateral case). Preoperative and postoperative clinical measurements have been conducted for all patients using the Knee Society Score (KSS). Hip-knee angle, recurvatum knee angle, and Insall-Salvati index were evaluated with full weight-bearing panoramic view X-ray preoperatively and postoperatively. The 2-year postoperative clinical KSS significantly improved from the preoperative scores. The average clinical KSS improved from 32,9 (range 3-48) preoperatively to 77,4 (range 60-88) postoperatively (P value < 0.005). The average functional KSS improved from 32,5 (range 10-60) preoperatively to 59,4 (range 30-95) postoperatively (P value < 0.005). TKR is a successful treatment in improving knee function and patient's quality of life. Using constrained implants, especially rotating hinge implants in polio patients with a quadriceps muscle weakness, could be a good alternative to maintain a physiological kinematics and reducing the revision rate due to knee instability.

The Impact of Morbid Obesity on In-hospital Outcomes after Revision Total Hip Arthroplasty: An Analysis of the National Inpatient Sample

Introduction:

There remain limited data on the effect of obesity on in-hospital outcomes after revision total hip arthroplasty (rTHA).

Methods:

Discharge data from the National Inpatient Sample were used to identify patients undergoing rTHA from 2006 to 2015. Propensity score analysis was done to analyze the effects of obesity and morbid obesity on in-hospital economic and complication outcomes after rTHA.

Results:

The estimated 460,297 rTHAs were done during the study period. Obese patients were more likely to suffer from any complication than not obese patients (41.44% versus 39.41%, P = 0.0085), and morbidly obese patients were more likely to suffer from any complication than obese patients (47.22% versus 41.44%, P < 0.0001). Obesity was associated with increased risk of postoperative anemia compared with not obese patients, while morbid obesity was associated with increased risk of postoperative anemia, hematoma/seroma, wound dehiscence, and postoperative infection (P < 0.05). Morbidly obese patients also had a significantly greater average length of stay (6.40 days) than obese (5.23 days) and not obese (5.37 days) patients (P < 0.0001).

Discussion:

Although both obesity and morbid obesity are associated with higher risk of in-hospital postoperative complications after rTHA, morbid obesity is a larger risk factor and is associated with a longer length of stay.

Alternative treatment of hip pain from advanced hip osteoarthritis utilizing cooled radiofrequency ablation: single institution pilot study

OBJECTIVE

To establish the effectiveness of cooled radiofrequency ablation in managing hip pain from osteoarthritis at 6 months after receiving treatment in patients who failed conservative treatments and are not surgical candidates due to comorbidities or unwillingness to undergo arthroplasty surgery by targeting the femoral and obturator branches and assessing the degree of hip pain relief and change of function.

MATERIALS AND METHODS

This prospective pilot study includes a total of 11 consecutive patients experiencing persistent chronic hip pain in the setting of advanced osteoarthritis. Patients initially underwent anesthetic blocks of the obturator and femoral nerve branches to determine cooled radiofrequency ablation candidacy. After adequate response to the anesthetic blocks (> 50% immediate pain relief), patients were subjected to the procedures 2-3 weeks later. Treatment response was evaluated utilizing clinically validated questionnaires and visual analog score in order to assess impact on pain severity, stiffness, and functional activities of daily living. Follow-up outcome scores were collected up to 6 months after cooled radiofrequency ablation procedure.

RESULTS

A total of 11 hips were treated consecutively between August 2019 and March 2020 (mean patient age 61.4 years; 8 M:3F). The mean total HOOS score improved significantly from baseline at 17.0 ± 6.0 to 52.9 ± 5.4 at a mean of 6.2 months after treatment (p < 0.0001), with significant improvement in mean pain score from 16.1 ± 6.6 to 53.4 ± 7.4 (p < 0.0001) and mean stiffness score from 15.0 ± 8.1 to 53.6 ± 11.0 (p < 0.0001). No major complications were encountered. No patients went on to re-treatment, surgery, or other intervention.

CONCLUSION

Image-guided obturator and femoral nerve cooled radiofrequency ablation is effective and safe in treating chronic hip pain/stiffness in the setting of advanced osteoarthritis.

Patterns and Predictors of Weight Change Before and After Total Hip Arthroplasty in Class 2 and 3 Obese Patients

BACKGROUND

This study aimed to better understand body mass index (BMI) change patterns and factors associated with BMI change before and after total hip arthroplasty (THA) in Class 2 and 3 obese patients, and assess if preoperative or postoperative BMI change affects postoperative clinical outcomes.

METHODS

We retrospectively reviewed World Health Organization Class 2 and 3 obese patients (BMI > 35.0 at surgery) who underwent THA at a tertiary medical center from 2010 to 2020. BMI was recorded at 1 year preoperatively (mean 11.6 months), and at most recent postoperative visit (mean 29.0 months). Baseline demographics and postoperative clinical outcomes were recorded.

RESULTS

We reviewed 436 THAs with a mean age of 59.9 (11.5) years. Leading up to surgery 55.5% had unchanged BMI, and postoperatively 48.2% had unchanged BMI. Multivariate logistic regression revealed that those who lost BMI preoperatively were more likely to gain BMI postoperatively (odds ratio [OR] 3.28, confidence interval [CI] 1.83-5.97, P = .005), but those who gained >5% BMI preoperatively had no association with BMI change postoperatively. Those in a higher BMI class preoperatively were less likely to gain BMI preoperatively (Class 3 obese patients: OR 0.001, CI 0.0002-0.004, P < .001). African American patients were more likely to gain BMI preoperatively (OR 2.32, CI 1.16-4.66, P = .017). We did not detect an association between BMI change and postoperative clinical outcomes.

CONCLUSION

In World Health Organization Class 2 or 3 obese patients, most maintained BMI between their first preoperative and final postoperative visit. Preoperatively, Class 3 obese patients were less likely to gain weight than Class 2 obese patients. The primary predictor of postoperative weight gain was preoperative weight loss. Weight change preoperatively and postoperatively were not associated with worse clinical outcomes.

Direct anterior approach vs Hardinge in obese and nonobese osteoarthritic patients: A randomized controlled trial

BACKGROUND

The increased prevalence of obesity has resulted in orthopedic surgeons being likely to face many patients with a high body mass index (BMI) who warrant total hip arthroplasties (THAs) over the coming years. Studies' findings considered the postoperative clinical, and functional outcomes in these patients are controversial, and selecting the most appropriate surgical approach remains debatable.

AIM

To compare pain-levels, functionality, and quality-of-life in obese and nonobese osteoarthritic patients who have undergone primary total hip arthroplasty through either direct-anterior-approach (DAA) or Hardinge-approach.

METHODS

One hundred and twenty participants (> 50 years) were divided into four groups according to the surgical approach (DAA or Hardinge) and patients' BMI (nonobese < 30 kg/m² vs obese ≥ 30 kg/m²). Outcomes were measured preoperatively and postoperatively (6^th and 12^th week). Pain was measured with Face Pain Scale-Revised (FPS-R). Functionality was measured with Timed Up & Go (TUG) test and Modified Harris Hip Score-Greek version (MHHS-Gr). Quality-of-life was evaluated with the 12-item-International Hip Outcome Tool-Greek version (iHOT12-Gr) (Clinical Trial Identifier: ISRCTN15066737).

RESULTS

DAA vs Hardinge: (week 6) DAA-patients showed 12.2% less pain, more functionality (14.8% shorter TUG-performance time, 21.5% higher MHHS-Gr), and 38.16% better quality-of-life (iHOT12-Gr) compared to Hardinge-patients (all P values < 0.001). These differences were further increased on week 12 (all P values ≤ 0.05)]. DAA-obese vs Hardinge–obese: (week 6) DAA-obese patients had less pain, shorter TUG-performance time, better MHHS-Gr and iHOT12-Gr scores than Hardinge-obese (all P values < 0.01). (Week 12) Only the TUG-performance time of DAA-obese was significantly shortened (22.57%, P < 0.001). DAA-nonobese vs DAA-obese: no statistically significant differences were observed comparing the 6^th and 12^th weeks' outcomes.

CONCLUSION

DAA-groups reported less pain, more functionality and better quality-of-life, compared to the Hardinge-groups. The DAA benefited obese and nonobese patients, similarly yet faster, suggesting that it should be the more preferred choice for obese patients, instead of Hardinge. However, more comparative studies with more extended follow-up periods are needed to confirm our results and better evaluate all patients' long-term outcomes.

Clinical Outcome of Primary Total Hip Arthroplasty in Patients with Morbid Obesity—Retrospective and Prospective Follow-Up Studies

Background and objective: There is a general clinical concern on the negative impact of obesity on surgical complications and functional outcomes. We hypothesized that the patients with morbid obesity are exceptionally prone to a significantly increased risk for surgical and short-term complications after primary total hip arthroplasty (THA). We aimed to identify the range of Body Mass Index (BMI) values of patients with a significant risk for lower functional improvement after THA. Materials and methods: In Stage 1 of the study, we conducted a retrospective comparative analysis of the rate of complications and functional outcomes in patients treated by primary THA, with normal weight (BMI 19–25, N = 1205) vs. Class 1 (BMI 26–34, N = 450), Class 2 (BMI 35–39, N = 183), and Class 3 (BMI ≥ 40, N = 47) obese patients. After the statistical similarity rates of complications and 6- and 12-month functional outcomes (by Harris Hip and SF-36 scores) were revealed in Class 1 patients and patients with normal BMI, we conducted the Stage 2 prospective study, by the same comparison protocol, on the cohorts of Class 2 (N = 29) and Class 3 (N = 16) patients compared to the Class 1 patients (N = 37) as controls. Results: Stage 1: There was no difference in surgical complications and function on 6- and 12-month postoperative follow-up (physical and mental) between Class 1 and patients with normal BMI (p > 0.05). Surgical complications were significantly higher in Class 2 (p < 0.05) and Class 3 (p < 0.001) patients. Functional activity on the 12-month follow-up increased significantly in all study groups, but in the Class 3 patients, the functional parameters were significantly lower (0.001). The mental health status on the follow-up was similar in all study groups. Stage 2 study revealed similar to the retrospective study comparison of parameters, except for the significantly lower mental health scores in Class 2 and Class 3 patients (p < 0.05) and functional scores in Class 3 patients (p < 0.05). Conclusion: Although the functional ability increased in all patients, it was significantly lower in Class 3 patients (with morbid obesity). Therefore, the patients with Class 1 and Class 2 obesity should be conceptionally distinguished from Class 3 patients in the decision-making process for a primary THA because of the less favorable functional and mental health improvement in those with morbid obesity (Class 3).

Morbid obesity is not a contraindication to lower limb arthroplasty

There are concerns that increased BMI is associated with a greater length of stay (LOS) and perioperative complications following total knee (TKR) and total hip replacements (THR). We analysed data from a six-month period to see if there was a correlation between BMI and LOS. We performed a subgroup analysis for patients with morbid obesity (BMI >40) looking at perioperative complications. 285 TKRs and 195 THRs were analysed. For TKRs, the average length of stay was 2.7 days. The average BMI was 32.4. There was no significant correlation between BMI and LOS (r=-0.0447, p=0.2267). The morbidly obese category (n=33) had the shortest LOS (2.5 days) compared to other BMI categories. 30- day readmission rate was 6%. 90-day re-admission rate was 12%. Six patients had minor wound issues requiring no intervention or antibiotics only. The was one prosthetic joint infection, one stitch abscess, one DVT and one patellar tendon injury. For THRs, the average LOS was 2.9 days. The average BMI was 29.9. There was no significant correlation between BMI and LOS (r=0.007, p=0.4613). The morbid obese category (n=9) had the shortest LOS (1.9 days) compared to other BMI categories. No patients were readmitted within 90 days or had documented complications. We have shown that for TKRs and THRs, increased BMI is not associated with increased LOS. The morbidly obese were found to have the shortest LOS. Re-admission rates and complications were commendable for patients with morbid obesity. BMI >40 is not a contraindication to TKR or THR.

Association of Surgical Experience With Risk of Complication in Total Hip Arthroplasty Among Patients With Severe Obesity

IMPORTANCE

Severe obesity is a risk factor for major early complications after total hip arthroplasty (THA).

OBJECTIVE

To determine the association between surgeon experience with THA in patients with severe obesity and risk of complications.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective population-based cohort study was performed in Ontario, Canada, from April 1, 2007, to March 31, 2017, with data analysis performed from March 2020 to January 2021. A cohort of patients who received a primary THA for osteoarthritis and who also had severe obesity (body mass index [calculated as weight in kilograms divided by height in meters squared] ≥40) at the time of surgery was defined. These patients were identified using the Canadian Institute for Health Information Discharge Abstract Database and physician claims from the Ontario Health Insurance Plan. Generalized estimating equations were used to determine the association between overall THA and severe obesity-specific THA surgeon volume and the occurrence of complications after controlling for potential confounders. The study hypothesized that surgeon experience specific to patients with severe obesity could further reduce the risk of complications.

EXPOSURES

Primary THA.

MAIN OUTCOMES AND MEASURES

Complications were considered as a composite outcome (revision, infection requiring surgery, or dislocation requiring reduction), within 1 year of surgery. This was defined before the study, as was the study hypothesis.

RESULTS

A total of 4781 eligible patients was identified. The median age was 63 (interquartile range [IQR], 56-69) years, and 3050 patients (63.8%) were women. Overall, 186 patients (3.9%) experienced a surgical complication within 1 year of surgery. The median overall THA surgeon volume was 70 (IQR, 46-106) cases/y, whereas the median obesity-specific surgeon volume was 5 (IQR, 2-9) cases/y. After controlling for patient and hospital factors, greater obesity-specific THA surgeon volume (adjusted odds ratio per additional 10 cases, 0.65 [95% CI, 0.47-0.89]; P = .007), but not greater overall THA surgeon volume (adjusted odds ratio per 10 additional cases, 0.97 [95% CI, 0.93-1.02]; P = .24), was associated with a reduced risk of complication.

CONCLUSIONS AND RELEVANCE

Increased surgeon experience performing THA in patients with severe obesity was associated with fewer major surgical complications. These findings suggest that surgeon experience is required to mitigate the unique anatomical challenges posed by surgery in patients with severe obesity. Referral pathways for patients with severe obesity to surgeons with high obesity-specific THA volume should be considered.

Increasing Reoperations and Failures With Increasing BMI in Patients Undergoing 2-Stage Exchange for Infected Total Hip Arthroplasty

BACKGROUND

While morbid obesity is associated with increased infection after total hip arthroplasty, little is known on the outcomes after 2-stage reimplantation for prosthetic joint infection (PJI) in this population. The purpose of this study is to evaluate the impact of morbid obesity (body mass index>40 kg/m2) on reinfection, postoperative complications, readmissions, and reoperations.

METHODS

We conducted a retrospective review of 107 patients undergoing first time 2-stage reimplantation for PJI from 2013 to 2019. 18 patients (50% women) with body mass index>40 kg/m2 were identified. To minimize confounders, three propensity score matched cohorts were created, yielding 16 nonobese (<30 kg/m2), 16 obese (30-39.9 kg/m2), and 18 morbidly obese (>40 kg/m2) patients. Outcomes were compared using chi-square or Fisher's exact tests. All patients had minimum 12-month follow-up, with mean follow-up of 36.3, 30.1, and 40.0 months in the nonobese, obese, and morbidly obese cohorts, respectively.

RESULTS

Compared with nonobese patients, morbidly obese patients had a higher rate of reinfection (0% vs 33%, P = .020 and higher likelihood of length of stay>4 days (19% vs 61%, P = .012). In addition, compared with nonobese and obese patients, morbidly obese patients had higher rate of return to the operating room for any reason (13% vs 19% vs 50%, respectively, P = .020). No differences between cohorts were found regarding complications, death, or revision surgery.

CONCLUSION

Morbidly obese patients have significantly increased risk of reinfection and reoperation after 2-stage reimplantation for PJI when compared with obese and nonobese patients. These data can be used to counsel morbidly obese patients contemplating total hip arthroplasty and supports the notion of deferring arthroplasty in this population pending optimization.

Robotics Versus Navigation Versus Conventional Total Hip Arthroplasty: Does the Use of Technology Yield Superior Outcomes?

BACKGROUND

The use of technology such as navigation and robotic systems may improve the accuracy of component positioning in total hip arthroplasty (THA), but its impact on patient-reported outcome measures (PROMs) remains unclear. This study aims to elucidate the association between the use of intraoperative technology and PROMs in patients who underwent primary THA.

METHODS

We retrospectively reviewed a consecutive series of patients who underwent primary THA between 2016 and 2020 and answered PROM questionnaires. Patients were separated into 3 groups depending on intraoperative technology utilization: computer-assisted navigation, robotic-assisted, or no technology (conventional) THA. Forgotten Joint Score-12 and Hip disability and Osteoarthritis Outcome Score, Joint Replacemen scores were collected at various time points. Demographic differences were assessed with chi-square and analysis of variance. Mean scores between groups were compared using univariate analysis of covariance, controlling for all significant demographic differences.

RESULTS

Of the 1960 cases identified, 896 used navigation, 135 used robotics, and 929 used no technology. There were significant statistical differences in one-year Hip disability and Osteoarthritis Outcome Score, Joint Replacement scores (85.23 vs 85.95 vs 86.76, respectively; P = .014) and two-year Forgotten Joint Score-12 scores (64.72 vs 73.35 vs 74.63, respectively; P = .004) between the 3 groups. However, these differences did not exceed the mean clinically important differences. Length of stay was statistically longest for patients who underwent conventionally performed THA versus navigation and robotics (2.22 vs 1.46 vs 1.91, respectively; P < .001). Surgical time was significantly longer for cases performed using robotics versus navigation and conventionally (119.61 vs 90.35 vs 95.35, respectively; P < .001).

CONCLUSION

Statistical differences observed between all modalities are not likely to be clinically meaningful with regard to early patient-reported outcomes. Although intraoperative use of technology may improve the accuracy of implant placement, these modalities have not yet translated into improved early reported functional outcomes.

LEVEL III EVIDENCE

Retrospective cohort.

Radiation exposure in fluoroscopy-guided anterior total hip arthroplasty: a systematic review

PURPOSE

To investigate the average fluoroscopy time, as well as the patient and surgical staff average radiation exposure in the context of intraoperative fluoroscopy use during anterior total hip arthroplasty (THA).

METHODS

PubMed, Cochrane, Embase, Web of Science and Scopus were systematically searched for studies pertaining to intraoperative anterior THA fluoroscopy (PROSPERO ID 258049). The comprehensive literary search was conducted using "THA," "fluoroscopy" and "radiation exposure" as the search criteria, which resulted in 187 total papers. Of these 187 papers, 11 studies were included in this systematic review as they involved anterior THA and specifically contained data regarding radiation exposure dose and/or time.

RESULTS

Eleven studies were included, enrolling 1839 patients. The average fluoroscopy time was 21.4 (95% confidence interval [CI] 16.6-26.1) seconds, whereas the average patient radiation dose was 1.8 × 10^-3 (95% CI 7.4 × 10^-4-2.9 × 10^-3) Gy.

CONCLUSIONS

Although several studies fail to report fluoroscopy time and radiation dose in THA patients, fluoroscopy-guided THA has emerged as a safe procedure. Additional studies may analyze if radiation exposure during the surgeon's THA learning curve is significantly higher, as well as what protocols may potentially reduce radiation exposure even further.

Risk Factors for Readmissions After Total Joint Replacement: A Meta-Analysis

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We performed a systematic review and meta-analysis of predictive modeling studies examining the risk of readmission after total hip arthroplasty (THA) and total knee arthroplasty (TKA) in order to synthesize key risk factors and evaluate their pooled effects. Our analysis entailed 15 compliant studies for qualitative review and 17 compliant studies for quantitative meta-analysis.

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A qualitative review of 15 predictive modeling studies highlighted 5 key risk factors for risk of readmission after THA and/or TKA: age, length of stay, readmission reduction policy, use of peripheral nerve block, and type of joint replacement procedure.

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A meta-analysis of 17 studies unveiled 3 significant risk factors: discharge to a skilled nursing facility rather than to home (approximately 61% higher risk), surgery at a low- or medium-procedure-volume hospital (approximately 26% higher risk), and the presence of patient obesity (approximately 34% higher risk). We demonstrated clinically meaningful relationships between these factors and moderator variables of procedure type, source of data used for model-building, and the proportion of male patients in the cohort.

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We found that many studies did not adhere to gold-standard criteria for reporting and study construction based on the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) and NOS (Newcastle-Ottawa Scale) methodologies.

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We recommend that these risk factors be considered in clinical practice and future work alike as they relate to surgical, discharge, and care decision-making. Future work should also prioritize greater observance of gold-standard reporting criteria for predictive models.

Obesity, Bariatric Surgery, and Hip/Knee Arthroplasty Outcomes

Obesity is an independent risk factor for osteoarthritis due to mechanical and inflammatory factors. The gold-standard treatment of end-stage knee and hip osteoarthritis is total joint arthroplasty (TJA). Weight loss decreases progression of osteoarthritis and complications following TJA in patients with obesity. Bariatric surgery allows significant, sustained weight loss and comorbidity resolution in patients with morbid obesity. Existing data describing bariatric surgery on TJA outcomes are limited but suggest a benefit to bariatric surgery prior to TJA. Further studies are needed to determine optimal risk stratification, bariatric procedure selection, and timing of bariatric surgery relative to TJA.

A Sensor-Based Screening Tool for Identifying High Pelvic Mobility in Patients Due to Undergo Total Hip Arthroplasty

There is increasing evidence that pelvic mobility is a critical factor to consider in implant alignment during total hip arthroplasty (THA). Here, we test the feasibility of using an inertial sensor fitted across the sacrum to measure change in pelvic tilt, and hence screen for patients with high pelvic mobility. Patients (n = 32, mean age: 57.4 years) due to receive THA surgery participated in the study. Measures of pelvic tilt were captured simultaneously using the device and radiograph in three functional positions: Standing, flexed-seated, and step-up. We found a strong correlation between the device and radiograph measures for the change in pelvic tilt measure from standing to flexed-seated position (R² = 0.911); 75% of absolute errors were under 5 degrees. We demonstrated that the device can be used as a screening tool to rapidly identify patients who would benefit from more detailed surgical planning of implant positioning to reduce future risks of impingement and dislocation.

The Effect of Body Mass Index Class on Patient-Reported Health-Related Quality of Life Before and After Total Hip Arthroplasty for Osteoarthritis: Registry-Based Cohort Study of 64,055 Patients

BACKGROUND

Overweight status and obesity represent a global epidemic, with serious consequences at the individual and community levels. The number of total hip arthroplasties (THAs) among overweight and obese patients is expected to rise. Increasing body mass index (BMI) has been associated with a higher risk of mortality and reoperation and lower implant survival. The evaluation of perioperative health-related quality of life (HRQoL) has recently gained importance because of its direct relation to, and impact on, patients' physical, mental, and social well-being as well as health-service utilization. We sought to evaluate the influence of BMI class on HRQoL preoperatively and at 1 year following THA in a register-based cohort study.

METHODS

This observational cohort study was designed and conducted on the basis of registry data derived from the Swedish Hip Arthroplasty Register (SHAR) and included 64,055 primary THAs registered between January 1, 2008, and December 31, 2015. Patients' baseline preoperative and 1-year postoperative EuroQol-5 Dimension-3 Level (EQ-5D-3L) responses were documented by the treating department and reported to the SHAR through the patient-reported outcome measures program. The EQ-5D-3L includes a visual analogue scale (EQ VAS), which measures the patient's overall health status.

RESULTS

At 1 year of follow-up, all BMI classes showed significant and clinically relevant improvements in all HRQoL measures compared with preoperative assessment (p < 0.05). Patients reported improved perception of current overall health status for the EQ VAS. Underweight, overweight, and all obesity classes showed increasingly worse 1-year HRQoL compared with normal weight, both with unadjusted and adjusted calculations.

CONCLUSIONS

In this study, we found that all BMI classes had significant improvement in HRQoL at 1 year following THA. Patients who were underweight, overweight, or obese (classes I to III), compared with those of normal weight, reported worse hip pain and EQ-5D-3L and EQ VAS responses prior to THA and at 1 year postoperatively. These results can assist both health-care providers and patients in establishing reasonable expectations about THA outcomes.

LEVEL OF EVIDENCE

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

Early Surgical Complications of Total Hip Arthroplasty in Patients With Morbid Obesity: Propensity-Matched Cohort Study of 3683 Patients

BACKGROUND

The aim of this study is to determine whether the high risk of surgical complications within 1 year of total hip arthroplasty (THA) is due to associated comorbidities or morbid obesity alone as measured by body mass index (BMI ≥ 40 kg/m²).

METHODS

Population-based retrospective cohort study was conducted of all adults in Ontario undergoing primary THA for osteoarthritis (2012-2018). All patients were followed for 1 year. Outcomes were compared among matched groups (hypertension, diabetes, chronic obstructive pulmonary disease, frailty, congestive heart failure, coronary artery disease, asthma, and Charlson score). Primary outcome measure was major surgical complications within 1 year (composite of deep infection requiring surgery, dislocation requiring closed or open reduction, and revision surgery).

RESULTS

A total of 3683 patients with morbid obesity were matched and had a significantly greater risk of major complications within 1-year (132 [3.6%] vs 54 [1.5%]; hazard ratio [HR] 2.54, 95% confidence interval [CI]; 1.98-3.25). This included greater risk for deep infection requiring surgery (100 [2.8%] vs 26 [0.7%]; HR 3.85, 95% CI; 2.70-45.48) and revision arthroplasty (86 [2.4%] vs 34 [0.9%]; HR 2.61, 95% CI; 1.92-3.55). Operative time was also longer with a median 116 (99-138) vs 102 (87-121) minutes. There were no significant differences in hospital stay, cost of acute care episode, or medical complications.

CONCLUSION

Patients' large body habitus seems to contribute to the increased risk of surgical complications within 1-year of THA. Future research is needed to identify ways of mitigating surgical complications such as centralizing care for this complex group of patients in specialist centers.

Impact of comorbidity on the short- and medium-term risk of revision in total hip and knee arthroplasty

Background

The impact of comorbidity on the risk of revision in patients undergoing Total Knee arthroplasty (TKA) and Total Hip Arthroplasty (THA) is not currently well known. The aim of this study was to analyze the impact of comorbidity on the risk of revision in TKA and THA.

Methods

Patients recorded in the Catalan Arthroplasty Register (RACat) between 01/01/2005 and 31/12/2016 undergoing TKA (n = 49,701) and THA (n = 17,923) caused by osteoarthritis were included. As main explanatory factors, comorbidity burden was assessed by the Elixhauser index, categorized, and specific comorbidities from the index were taken into account. Descriptive analyses for comorbidity burden and specific conditions were done. Additionally, incidence at 1 and 5 years’ follow-up was calculated, and adjusted Competing Risks models were fitted.

Results

A higher incidence of revision was observed when the number of comorbidities was high, both at 1 and 5 years for THA, but only at 1 year for TKA. Of the specific conditions, only obesity was related to the incidence of revision at 1 year in both joints, and at 5 years in TKA. The risk of revision was related to deficiency anemia and liver diseases in TKA, while in THA, it was related to peripheral vascular disorders, metastatic cancer and psychoses.

Conclusions

Different conditions, depending on the joint, might be related to higher revision rates. This information could be relevant for clinical decision-making, patient-specific information and improving the results of both TKA and THA.

Total Hip Arthroplasty in the Obese Patient: Tips and Tricks and Review of the Literature

AIM

There is a lack of consensus on the optimal method of performing primary hip arthroplasty in obese patients and limited evidence. This article presents a series of considerations based on the authors' experiences as well as a review of the literature.

PREOPERATIVE CARE

In the preoperative phase, an informed consent process is recommended. Weight loss is recommended according to NHS England guidelines, and body habitus should be taken into account. When templating, steps are taken to avoid overestimating the implant size.

SURGICAL PROCEDURE

During the surgical procedure, specialist bariatric equipment is utilised: bariatric beds, extra supports, hover mattresses, longer scalpels, diathermy, cell saver and minimally invasive surgery equipment. Communication with the anaesthetist and surgical team to anticipate is vital. Intraoperative sizing and imaging, if required, should be considered. Pneumatic foot pumps are preferable for VTE prophylaxis. Regional anaesthesia is preferred due to technical difficulty. IV antibiotics and tranexamic acid are recommended. The anterior and posterior surgical approaches are most frequently used; we advocate posterior. Incisions are extensile and a higher offset is considered intraoperatively, as well as dual mobility and constrained liners to reduce dislocation risk. When closing the wound, Charnely button and sponge should be considered as well as negative pressure wound dressings (iNPWTd) and drains.

POST-OPERATIVE CONSIDERATIONS

Postoperatively, difficult extubation should be anticipated with ITU/HDU beds available. Epidural anaesthetics for postoperative pain management require higher nursing vigilance. Chemical prophylaxis is recommended.

CONCLUSION

Despite being technically more difficult with higher risks, functional outcomes are comparable with patients with a normal BMI.

Maryland's Global Budget Revenue model associated with lower inpatient costs and 30-day readmissions in patients undergoing total hip arthroplasty

BACKGROUND

Maryland implemented the Global Budget Revenue (GBR) to reduce hospital costs, improve quality, and decrease readmissions. Studies assessing its impact on inpatient total hip arthroplasty (THA) procedures are lacking. This study compared before and after GBR changes in 1) patient characteristics; 2) discharge dispositions and lengths of stay (LOS); 3) costs and charges of inpatient stays; and 4) 30-day readmission rates (RR) for THA recipients.

METHODS

The Maryland State Inpatient Database was queried for patients who underwent THA between 2010 and 2016 utilizing the ICD-9 and ICD-10 procedure codes (n = 43,251). Pre- and post-GBR periods were grouped as 2010 to 2013 and 2014 to 2016, respectively. Chi-square analyses were used to analyze patient characteristics. Student's t-tests were utilized to compare ages, LOS, costs, charges, and RR.

RESULTS

There were no differences in the proportion of minorities undergoing THA between the pre- and post-GBR periods (18.3% vs 19.4% African American, 1.2% vs 1.3% Hispanic; P = .056). The number of THA patients with Medicaid insurances increased during post-GBR (4.0% vs 6.7%; P < .001). There was an increased rate of home discharges during post-GBR (33.1% vs 40.9%; P < .001). We found lower LOS (-0.50 days; 95% CI: -0.458 to -0.533; P < .001), mean inpatient costs (-$1417.44; 95% CI -$1143.76 to -$1150.32; P < .001), and mean inpatient charges (-$2196.50; 95% CI: -$1980.10 to -$2412.90; P < .001) during the post-GBR period. There were lower 30-day RR during the post-GBR period (-0.9%; P < .001).

CONCLUSIONS

Our findings suggest favorable preliminary results for patients undergoing THA under the GBR model.

Effect of morbid obesity on patient-reported outcomes in total joint arthroplasty: a minimum of 1-year follow-up

The objective of this study is to explore the effect of morbid obesity on patient-reported outcomes in primary total joint arthroplasty. We retrospectively reviewed 755 primary total joint arthroplasty cases with a minimum of 1-year follow-up. Two groups were compared: (1) patients with BMI < 40 and (2) those with BMI ≥ 40. The primary outcome was the difference in Short Form-12 physical component summary, Short Form-12 mental component summary, Western Ontario and McMaster Universities Osteoarthritis Index, and patient satisfaction. Multivariate analyses were performed to control for potential confounding factors. 37 patients (5%) were morbidly obese. Morbidly obese patients undergoing total knee arthroplasty had significantly lower net gains in their Short Form-12 physical component summary (P = .008), Short Form-12 mental component summary (P = .049), and Western Ontario and McMaster Universities Osteoarthritis Index (P = .009) in the first 6 months only. For total hip arthroplasty, morbid obesity did not affect any of the outcomes measured (P > .05). There was also no difference in patient satisfaction rates between the two groups (P = .401 and .143 for total hip arthroplasty and total knee arthroplasty, respectively). The impact of morbid obesity on patient-reported outcomes appears to be limited to total knee arthroplasty only in the initial 6 months after surgery.

Total hip arthroplasty in obesity: separating 'fat' from fiction

Obesity is a modern-day epidemic with increasing prevalence that is directly impacting the global burden of primary total hip arthroplasty. The risk of requiring total hip arthroplasty for osteoarthritis increases incrementally with increasing obesity class. Surgical intervention in obese patients presents a set of unique challenges that should be recognized by the treating medical team. Although predominantly satisfactory outcomes have been reported, perioperative anaesthetic and surgical concerns require thorough patient assessment. There is an increased potential risk of thrombogenic and septic complications, but the body mass index cutoff level beyond which total hip arthroplasty should not be offered in the obese patient remains controversial. Preoperative medical optimization of the patient and appropriate intraoperative interventions are essential to mitigate the risk of complications.

Body mass index is associated with risk of reoperation and revision after primary total hip arthroplasty: a study of the Swedish Hip Arthroplasty Register including 83,146 patients

Background and purpose - The prevalence of obesity is on the rise, becoming a worldwide epidemic. The main purpose of this register-based observational study was to investigate whether different BMI classes are associated with increased risk of reoperation within 2 years, risk of revision within 5 years, and the risk of dying within 90 days after primary total hip arthroplasty (THA). We hypothesized that increasing BMI would increase these risks. Patients and methods - We analyzed a cohort of 83,146 patients who had undergone an elective THA for primary osteoarthritis between 2008 and 2015 from the Swedish Hip Arthroplasty Register (SHAR). BMI was classified according to the World Health Organization (WHO) into 6 classes: < 18.5 as underweight, 18.5-24.9 as normal weight, 25-29.9 as overweight, 30-34.9 as class I obesity, 35-39.9 as class II obesity, and ≥ 40 as class III obesity. Results - Both unadjusted and adjusted parameter estimates showed increasing risk of reoperation at 2 years and revision at 5 years with each overweight and obesity class, mainly due to increased risk of infection. Uncemented and reversed hybrid fixations and surgical approaches other than the posterior were all associated with increased risk. Obesity class III (≥ 40), male sex, and increasing ASA class were associated with increased 90-day mortality. Interpretation - Increasing BMI was associated with 2-year reoperation and 5-year revision risks after primary THA where obese patients have a higher risk than overweight or normal weight patients. As infection seems to be the main cause, customizing preoperative optimization and prophylactic measures for obese patients may help reduce risk.