The influence of obesity on functional outcome and quality of life after total knee arthroplasty: a ten-year follow-up study

Predictors of health-related quality of life after total knee arthroplasty: a case-control study

Total knee arthroplasty (TKA) improves patients' Health-related quality of life (HRQoL) compared to before surgery. However, based on our knowledge, the improvement in HRQoL after TKA, which depends on various factors, has yet to be investigated compared to healthy people. This study aimed to evaluate the HRQoL of patients compared to healthy people and the factors affecting the HRQoL after TKA. In this matched case-control study (1002 participants), HRQoL in 501 patients who underwent TKA between 2015 and 2022 at Shafa Yahyainan Hospital affiliated with Iran University of Medical Sciences were compared with 501 healthy controls. HRQoL was evaluated in two parts (before compared to 12 months after TKA and 12 months after TKA compared to the healthy population). The 36-item short-form health survey (SF-36) was used to evaluate HRQoL 12 months after surgery. The influencing factors on HRQoL were evaluated by multivariate logistic regression analysis. No significant difference was observed in the demographic characteristics of the participants in the two groups. The mean overall SF-36 score, 12 months after surgery, significantly improved compared to before surgery (64.21 ± 22.2 vs. 37.55 ± 15.13, p:0.001). The mean total score of SF-36 was statistically similar between the case and control groups (64.21 ± 22.2 VS 72.53 ± 25.3). The multivariate analysis showed that sex, BMI, number of comorbidities, postoperative compliance, and complications were significantly related to the decrease in patients' HRQoL (P < 0.001).TKA can improve the HRQoL except for two subscales of happiness/vitality and physical performance, similar to the healthy population. Female gender, obesity and overweight, comorbidity, bilateral TKA, non-adherence to postoperative physiotherapy, and complications were associated with decreased HRQoL.

Factors Correlated with the Quality of Life after Total Knee Arthroplasties: A Literature Review

Introduction

Total Knee Arthroplasty (TKA) has been widely reported to improve outcomes and quality of life (QoL) in patients with knee osteoarthritis (KOA), but there are still 15 - 20% of patients still experience pain, physical limitations, and other complications after TKA. Therefore, it is necessary to identify various factors that correlate with QoL from current evidence. The objective is to review the literature on factors that correlate with QoL in patients who underwent TKA.

Materials and methods

A literature search was conducted on five databases, i.e. ProQuest, CINAHL, Medline, Embase, and Scopus, using the following keywords: total knee arthroplasty (TKA), post-operative, quality of life (QoL), and outcome. There were no restrictions on the research design.

Results

This review found 14 articles (7 prospective studies and 7 retrospective studies) involving 15,972 patients who underwent TKA, with an age range of 32 - 94 years. All articles reported improvement in QoL after TKA. The review revealed 30 factors, of which 15 factors were significantly correlated with QoL after TKA. The factors were grouped into four types: demographic, socioeconomic, clinical, and psychosocial factors.

Conclusion

Information regarding factors that correlate with QoL after TKA can be used for directing treatment and discharge planning according to the patient's factors.

Association between Obesity and Short-Term Patient-Reported Outcomes following Total Knee Arthroplasty: A Retrospective Cohort Study in Japan

Background: This study investigated the association between obesity and short-term patient-reported outcomes after total knee arthroplasty (TKA). Methods: The primary outcomes were the Western Ontario and McMaster Universities Osteoarthritis Index's (WOMAC) pain and function scores. Data were collected preoperatively and 2 and 4 weeks after surgery. Patients were stratified into three groups based on body mass index (BMI): normal weight (BMI < 24.99 kg/m2), overweight (25 ≤ BMI < 29.99 kg/m2), and obese (BMI ≥ 30 kg/m2). The associations between BMI and the WOMAC pain and function scores were assessed using generalized linear mixed models. Results: Among the 102 patients (median age: 75.0, women [85.3%]), 29.4%, 48.0%, and 22.5% were normal weight, overweight, and obese, respectively. The mean pain and function scores at baseline were similar across the BMI-stratified groups (p = 0.727 and 0.277, respectively). The pain score significantly improved 2 weeks post-surgery (p = 0.001). The function score improved significantly 4 weeks post-surgery (p < 0.001). The group and group-by-time interaction effects lacked statistical significance. Conclusions: All patients statistically and clinically showed relevant pain reduction and functional improvement shortly after TKA, irrespective of their obesity status. These data may help healthcare professionals discuss the expectations of pain amelioration and functional improvement with TKA candidates.

Long-term clinical and radiological outcome of a cementless titanium-coated total knee arthroplasty system

INTRODUCTION

To ensure a high-quality standard, it is important to frequently evaluate different prostheses models to avoid prostheses with high failure rates. Thus, the aim of the study was to evaluate the long-term outcome of the uncemented titanium-coated total knee arthroplasty (TKA) system (Advanced Coated System (ACS) III, Implantcast, GERMANY). We hypothesized that the ACS III would have a similar performance as other cemented TKA systems.

MATERIALS AND METHODS

A total of 540 ACS III mobile-bearing knee joint prostheses were implanted in 495 patients. The visual analogue scale (VAS) score, Tegner activity score (TAS), knee society score (KSS), Western Ontario and McMaster (WOMAC) score, and the Short Form 12 (SF-12) score for the evaluation of quality of life (QoL) were taken after at least 9 years of follow-up. In addition, we measured range of motion (ROM) and assessed potential sex differences. In addition, the survival analysis was calculated at a median follow-up of 16.7 years.

RESULTS

At the final follow-up, 142 patients had died, and 38 had been lost to follow-up. The rate of revision-free implant survival at 16.7 years was 90.0% (95% CI 87.1-92.2%) and the rate of infection-free survival was 97.0% (IQR 95.2-98.2%). The reasons for revision surgery were aseptic loosening (32.9%), followed by infection (27.1%), inlay exchange (15.9%), and periprosthetic fractures (5.7%). At the clinical follow-up visit, the mean VAS score was 1.9 ± 1.9, the median TAS was 3 (IQR 2-4), and the mean KSS for pain and function were 83.5 ± 15.3 and 67.5 ± 25.2, respectively. The mean WOMAC score was 81.1 ± 14.9, and the median SF-12 scores for physical and mental health were 36.9 (IQR 29.8-45.1) and 55.8 (IQR 46.2-61.0), respectively. The mean knee flexion was 102.0° ± 15.4°. Male patients had better clinical outcome scores than female patients [SF-12 mental health score, p = 0.037; SF-12 physical health score, p = 0.032; KSS pain score (p < 0.001), and KSS functional score (p < 0.001)].

CONCLUSION

The ACS III TKA system is a suitable option for the treatment of end-stage osteoarthritis of the knee joint because of its adequate long-term survival. Our findings are in line with published data on similar TKA systems that have shown favourable clinical scores in males.

LEVEL OF EVIDENCE

Level III-Retrospective cohort study.

Comparison of time courses in postoperative functional outcomes between simultaneous bilateral and unilateral total knee arthroplasty with propensity score matching

INTRODUCTION/OBJECTIVES

No consensus has been reached on which is better in terms of functional outcomes between simultaneous bilateral and unilateral total knee arthroplasty (TKA). As patient characteristics, such as age, sex, and body mass index, have significant effects on functional outcomes after TKA, these factors should be matched before comparisons are made. This study aimed to compare time courses in functional outcomes between simultaneous bilateral TKA and unilateral TKA after matching the patient characteristics.

MATERIALS AND METHODS

In this retrospective study, the clinical records of patients admitted to a hospital were reviewed. Of 425 patients, 43 underwent simultaneous bilateral TKA, whereas 382 underwent unilateral TKA. Propensity score matching was performed for age, sex, and body mass index between simultaneous bilateral and unilateral TKA patients. Therapists measured pain intensity, knee extensor strength, and knee-specific functional outcomes by using the new knee society score, including total score, symptoms, patient satisfaction, patient expectations, and functional activities preoperatively and 3 and 12 months postoperatively. Two-way repeated analysis of variance was performed to compare the time courses in functional outcomes between simultaneous bilateral and unilateral TKA.

RESULTS

After propensity score matching, 40 patients each for underwent bilateral TKA and unilateral TKA were selected. Knee extensor strength in simultaneous bilateral TKA patients was significantly lower than that in unilateral TKA patients at 3 months postoperatively (p = 0.04). A significant interaction was observed between the effects of time and group on knee extensor strength (F [1, 78] = 3.338; interaction: p = 0.042; η2 = 0.052). No significant interactions were found among the other variables measured.

CONCLUSIONS

Patients who underwent simultaneous bilateral TKA should undergo postoperative rehabilitation focused on alleviating delayed recovery in knee extensor strength during the acute phase.

Increase in Postoperative Body Mass Index in Patients After Total Knee Arthroplasty

Objectives The aim of this is to investigate the changes in body mass index (BMI) following knee arthroplasty and to evaluate their impact on patient-reported outcomes and functional evaluations. Methods This observational study included 90 patients who underwent total knee arthroplasty (TKA) and were followed up for a median period of 2.6 years. BMI measurements were recorded before and after surgery, and patient-reported outcomes and functional evaluations were assessed using standardized scales and tests. Results Following TKA, BMI increased statistically significantly (Wilcoxon signed-rank test, p < 0.000). In addition, half of the patients experienced an increase in BMI, with 32% moving up in their BMI category. However, there were no clinically significant differences in patient-reported outcomes or functional evaluations between the group that gained BMI and the group that maintained or lost BMI. Conclusion This study reveals that patients tend to have increased BMI following TKA. However, these BMI changes do not significantly impact patient-reported outcomes or functional evaluations. It underscores the importance of patient education regarding healthy lifestyle habits, including diet and physical activity, to address postoperative weight gain effectively.

Robotic-assisted technology does not influence functional outcomes among obese and morbidly obese total knee arthroplasty patients

PURPOSE

Despite benefits of total knee arthroplasty (TKA) on function and quality of life, obese patients have less improved functional outcomes following TKA compared to their normal weight counterparts. Furthermore, obesity is a risk factor for aseptic loosening and revision surgery following TKA. With known benefits of robotic-assisted TKA (RaTKA) in precision and patient satisfaction, we aimed to evaluate the differences in patient reported outcome and early complication rates for patients undergoing RaTKA versus conventional TKA among patients of varying BMI groups.

METHODS

This study was a retrospective cohort study of patients who underwent conventional versus RaTKA. Patients were grouped by BMI range (< 30 kg/m2, 30-40 kg/m2, and > 40 kg/m2). Patient-reported outcomes were measured by Oxford Knee Scores and 12-Item Short Form Survey scores preoperatively, 6-month, 1-year, and 2-year postoperatively. Mixed-effects linear models were built for each patient-reported outcome to assess the interaction between type of surgery and BMI while adjusting for known confounders such as demographic variables.

RESULTS

A total of 350 patients (n = 186 RaTKA, n = 164 conventional TKA) met inclusion criteria. SF-12 physical scores were significantly higher at 2-year follow-up among non-obese patients compared to obese and morbidly obese patients (p = 0.047). There was no statistically significant interaction between the type of surgery performed (RaTKA versus conventional TKA) and obesity regarding their effects on patient reported outcomes.

CONCLUSIONS

This study demonstrates no differences in functional outcomes among patients undergoing RaTKA compared to conventional TKA. Furthermore, obesity had no significant effect on this association.

LEVEL OF EVIDENCE

III.

Functional recovery after total hip/knee replacement in obese people: A systematic review

OBJECTIVE

Several studies have investigated the influence of body mass index (BMI) on functional gain after total hip replacement (THR) or total knee replacement (TKR) in osteoarthritis, with contradictory results. This systematic literature review was conducted to ascertain whether obesity affects functional recovery after THR or TKR in the short (<1 year), medium (<3 years) and long term (>3 years).

METHODS

The study was registered with PROSPERO and conducted according to the PRISMA guidelines. A systematic literature search was conducted across Medline and EMBASE databases for articles published between 1980 and 2020 that investigated patient-reported measures of functional recovery after THR and TKR in participants with osteoarthritis and obesity (defined as BMI ≥30 kg/m²).

RESULTS

Twenty-six articles reporting on 68,840 persons (34,955 for THR and 33,885 for TKR) were included in the final analysis: 5 case-control studies, 21 cohort studies (9 for THR only, 10 for TKR only and 2 for both). The average minimum follow-up was 36.4 months, ranging from 6 weeks to 10 years. Most studies found significantly lower pre-operative patient-reported functional scores for participants with obesity. After THR, there was a small difference in functional recovery in favor of those without obesity in the short term (<6 months), but the difference remained below the minimal clinically important difference (MCID) threshold and disappeared in the medium and long term. After TKR, functional recovery was better for those with obesity than those without in the first year, similar until the third year, and then decreased thereafter.

CONCLUSIONS

Although there is a paucity of high-quality evidence, our findings show substantial functional gains in people with obesity after total joint replacement. Functional recovery after THR or TKR does not significantly differ, or only slightly differs, between those with and without obesity, and the difference in functional gain is not clinically important.

PROSPERO NUMBER

CRD42018112919.

The influence of obesity on functional outcomes and patient satisfaction 8 weeks after total knee arthroplasty: results of the prospective FInGK study

OBJECTIVES

To investigate obese versus non-obese subjects´ knee joint function, stiffness, pain, expectations, and outcome satisfaction before and two months after total knee arthroplasty (TKA).

METHODS

This study is a secondary analysis of data retrieved via a prospective single-centre cohort study investigating knee joint function and health care services utilization in patients undergoing TKA (FInGK Study). For the primary study, elective TKA patients were consecutively recruited between December 2019 and May 2021. Preoperative expectations, Western Ontario and McMasters Universities Osteoarthritis Index (WOMAC), surgery outcome satisfaction, and sociodemographic variables were assessed via self-reported questionnaires. In the current study, obese (Body Mass Index (BMI) ≥ 30 kg/m²) versus non-obese (BMI < 30 kg/m²) subjects' data were exploratively compared before and two months after TKA. Multivariable logistic regression assessed factors associated with TKA satisfaction two months postoperatively. Linear regression evaluated factors associated with higher WOMAC change two months postoperatively.

RESULTS

A total of 241 subjects participated (response: 85.2%). Eighty-seven were non-obese (mean age: 70.7 years, 63.2% female) and 154 were obese (mean age: 67.1 years, 57.8% female). Obese subjects reported inferior pre- and postoperative pain and knee joint function compared to non-obese subjects. Yet, WOMAC scores of obese and non-obese subjects significantly improved from preoperative means of 52.6 and 46.8 to 32.3 and 24.4 after surgery, respectively. The only significant TKA satisfaction predictor was subjects' smoking status. Non-obesity and worse preoperative WOMAC scores were predictive of higher WOMAC change scores after two months.

CONCLUSION

Both obese and non-obese subjects reported significant symptom improvements. However, as obese subjects' short-term outcomes were still inferior, more research on TKA rehabilitation measures adapted to the needs of this growing patient group is warranted to maximize their benefits from TKA.

Alignment prior to total knee arthroplasty in high tibial osteotomy patients has no effect on subsequent functional outcomes

INTRODUCTION

The influence of prior high tibial osteotomy (HTO) on total knee arthroplasty (TKA) functional outcomes remains widely debated. Alignment of failed HTO can pose technical challenges with subsequent TKA. The primary aim of this study was to evaluate the influence of HTO alignment on the clinical outcomes of subsequent TKA. The secondary aim was to compare the time to TKA for each HTO alignment type.

METHODS

Patients who underwent TKA post lateral closing-wedge HTO for symptomatic medial compartment osteoarthritis between 2001 and 2014 were prospectively followed up for 2 years. A total of 159 patients were assigned to three groups based on their pre-TKA femora tibia angles using long lower limb radiographs: varus alignment (VrA) ≤ 3^o valgus, neutral alignment (NA) 3-9^o valgus alignment, valgus alignment (VlA) ≥ 9^o valgus. Functional outcomes were quantified using Knee Society Function Score and Knee Scores (KSFS and KSKS respectively), modified Oxford Knee Score (OKS), Short Form 36 Physical Component Score (SF-36 PCS), and SF-36 Mental Component Score (SF-36 MCS). Pre-operative and post-operative knee range of motion were also measured.

RESULTS

Mean pre-TKA KSKS in VrA patients (35 ± 18) was significantly lower than both NA (51 ± 19) and VlA (40 ± 21) patients (p < .05). Otherwise, there was no significant difference in functional outcome scores (KSFS, KSKS, OKS, SF-36 PCS and SF-36 MCS) or range of motion at 6 months and 2 years post-TKA. The mean duration from HTO to TKA was 12 ± 7 years with no significant differences between VrA, NA, and VlA HTO to TKA (13 ± 7 years, 13 ± 6 years and12 ± 8 years respectively, p > .05).

CONCLUSION

HTO alignment did not influence time to subsequent TKA. HTO alignment did not influence early outcomes as well as radiological outcomes of subsequent TKA.

LEVEL OF EVIDENCE

III.

No differences in 10-year clinical outcomes and quality of life between patients with different mediolateral femoral component positions in fixed-bearing medial unicompartmental knee arthroplasty

PURPOSE

There has been a paucity of literature evaluating the role of mediolateral femoral component position (FCP) in medial unicompartmental arthroplasty (UKA). Hence, the aim of this study is to evaluate whether the mediolateral FCP in UKA will affect the 10-year clinical outcomes and quality of life of patients who underwent medial UKA.

METHODS

Data of 262 patients who underwent medial UKA were analyzed. All patients were assessed at 6 months, 2 years and 10 years using the Knee Society Function Score, Knee Society Knee Score, Oxford Knee Score, Short-Form 36 Physical/Mental Component Scores and postoperative satisfaction. The mediolateral FCP on postoperative radiographs was measured by independent assessors using the Picture Archiving and Communication Systems. 144 patients were distributed into group C (center), 98 into group M (medial) and 20 into group L (lateral) according to FCP, and one-way ANOVA was used to compare the functional outcomes of the three groups.

RESULTS

No statistical differences were found between the three groups in terms of 10-year clinical outcomes, quality of life, satisfaction rates and revision rates.

CONCLUSION

Differences in mediolateral FCP did not result in significant difference in 10-year postoperative clinical outcomes for patients who underwent fixed-bearing medial UKAs.

LEVEL OF EVIDENCE

Retrospective study, Level III.

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.

Preoperative Factors Affecting the Patient-Reported Outcome Measures following Total Knee Replacement: Socioeconomic Factors and Preoperative OKS Have a Clinically Meaningful Effect

The Oxford Knee Score (OKS) is a patient-reported outcome questionnaire typically used to assess function and pain in patients undergoing total knee replacement (TKR). However, research is inconclusive as to which preoperative factors are important in explaining variation in outcome following TKR. The operative records of 12,709 patients who underwent primary TKR over a 9-year period were analyzed. The following variables were collected for each patient: age, sex, body mass index (BMI), Index of Multiple Deprivation decile rank, side of operation, diagnosis, the American Society of Anaesthesiologists (ASA) grade, preoperative OKS, EQ-5D index score, EuroQol visual analog scale (EQ-VAS) score, the postoperative OKS at 1 and 2 years. Generalized linear regression models were performed at 1 and 2 years to investigate the effect of the preoperative variables on the postoperative OKS. The effect of age, sex, BMI, Index of Multiple Deprivation decile rank, diagnosis, ASA grade, preoperative OKS, EuroQoL five-dimensional (EQ-5D) index score, and EQ-VAS score were all statistically significant in explaining the variation in OKS at 1 and 2 years postoperatively, with critical level of significance of 0.05 (5%). Being male aged 60 to 69 years of normal BMI, ASA grade I (fit and healthy), living in an affluent area, not reporting preoperative anxiety/depression, were associated with an enhanced mean postoperative OKS at both 1 and 2 years. When adjusted for potential confounding, age of 60-69 years, male sex, normal BMI, lower ASA grade, higher Index of Multiple Deprivation and higher pre-operative EQ-5D, EQ-VAS and OKS were identified as factors that resulted in higher post-operative OKS after primary TKR.

Projected Prevalence of Obesity in Primary Total Knee Arthroplasty: How Big Will the Problem Get?

BACKGROUND

Obesity is a well-established risk factor for complications following primary total knee arthroplasty (TKA). The purpose of this study is to utilize 3 national databases to develop projections of obesity within the general population and primary TKA patients in the United States through 2029.

METHODS

Data from the National Surgical Quality Improvement Program (NSQIP), the Behavior Risk Factor Surveillance System (BRFSS), and the National Health and Nutrition Examination Survey were queried for years 1999-2019. Current Procedural Terminology code 27447 was used to identify primary TKA patients in NSQIP. Individuals were categorized according to body mass index (kg/m²) by year: normal weight (≤24.9); overweight (25.0-29.9); obese (30.0-39.9); and morbidly obese (≥40). Multinomial logistic regression was used to project categorical body mass index data for years 2020-2029.

RESULTS

A total of 8,372,221 individuals were included (7,986,414 BRFSS, 385,807 NSQIP TKA). From 2011 to 2019, the prevalence of normal weight and overweight individuals declined in the general population (BRFSS) and in primary TKA. Prevalence of obese/morbidly obese individuals increased in the general population from 31% to 36% and in primary TKA from 60% to 64%. Projection models estimate that by 2029, 46% of the general population will be obese/morbidly obese and 69% of primary TKA will be obese/morbidly obese.

CONCLUSION

By 2029, we estimate ≥69% of primary TKA to be obese/morbidly obese. Increased resources dedicated to care pathways and research focused on improving outcomes in obese arthroplasty patients will be necessary as this population continues to grow.

LEVEL OF EVIDENCE

Level III, Retrospective Cohort Study.

Are Body Mass Index Cutoffs Creating Racial, Ethnic, and Gender Disparities in Eligibility for Primary Total Hip and Knee Arthroplasty?

BACKGROUND

Unabated increases in the prevalence of obesity among American adults have disproportionately affected women, Black persons, and Hispanic persons. The purpose of this study was to evaluate for disparity in rates of patient eligibility for primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) based on race and ethnicity and gender by applying commonly used body mass index (BMI) eligibility criteria to two large national databases.

METHODS

We retrospectively reviewed data from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database for the years 2015-2019 for primary THA and TKA and the National Health and Nutrition Examination Survey (NHANES) from 2011-2018. Designations of race and ethnicity were standardized between cohorts. BMI cutoffs of <50 kg/m², <45 kg/m², <40 kg/m², and <35 kg/m² were then applied. Rates of eligibility for surgery were examined for each respective BMI cutoff and stratified by age, race and ethnicity, and gender.

RESULTS

143,973 NSQIP THA patients, 242,518 NSQIP TKA patients, and 13,255 NHANES participants were analyzed. Female patients were more likely to be ineligible for surgery across all cohorts for all modeled BMI cutoffs (P < .001 for all). Black patients had relatively lower rates of eligibility across all cohorts for all modeled BMI cutoffs (P < .0001 for all). Hispanic patients had disproportionately lower rates of eligibility only at a BMI cutoff of <35 kg/m².

CONCLUSION

Using BMI cutoffs alone to determine the eligibility for primary THA and TKA may disproportionally exclude women, Black persons, and Hispanic persons. These data raise concerns regarding further disparity and restriction of arthroplasty care to vulnerable populations that are already marginalized.

LEVEL OF EVIDENCE

Retrospective Cohort Study, Level III.

Clinical Outcomes of Scarf-Akin Osteotomy for Hallux Valgus With Simultaneous Bunionette Correction: A Propensity Score-Matched Cohort Analysis

Hallux valgus and bunionette (Tailor's bunion) deformities are debilitating forefoot deformities that may occur together. Successful outcomes of surgery for either pathology have been well-described; however, the literature is sparce on outcomes of patients undergoing simultaneous surgery for both deformities. Between 2007 and 2018, 429 patients underwent a scarf-Akin osteotomy, and 20 patients underwent simultaneous bunionette surgery. Propensity score matching was used to match the scarf + bunionette group in a 1:2 ratio to a corresponding scarf only group using logistic regression. Their hallux and fifth metatarsal visual analogue scale (VAS), American Orthopaedic Foot & Ankle Society (AOFAS) Hallux Metatarsophalangeal-Interphalangeal Scale, Short Form-36 (SF-36), expectations and satisfaction scores were recorded at preoperative, 6-month and 2-year intervals. There were no differences in baseline characteristics between groups after matching (p > .05). At 6 months, the scarf + bunionette group had a significantly worse fifth metatarsal AOFAS (80.7 vs 92.9, p = .002) and VAS (1.5 vs 0.1, p = .008). However, at 2 years, greater improvements in the scarf + bunionette group resulted in no significant differences for fifth metatarsal AOFAS and VAS. The scarf + bunionette group had better SF-36 scores in the domains of physical functioning, bodily pain, general health and mental health (p < .05). Scarf + bunionette patients trended toward higher satisfaction (100.0% vs 85.0%, p = .165) and expectation fulfilment (95.0% vs 80.0%, p = .249) at 2 years, although not significant with the available numbers. In patients with similar baseline hallux and fifth metatarsal pain and function, simultaneous surgery and a scarf osteotomy alone result in similar improvements to pain and function at 2 years. However, patients who undergo both procedures have higher quality of life scores.

Pain, Function, and Satisfaction After Total Knee Arthroplasty, with or Without Bariatric Surgery

BACKGROUND

The impact of obesity on patient-reported outcome (PRO) after total knee arthroplasty (TKA) surgery has demonstrated varying results. We evaluated knee pain, Activity in Daily Life function (ADL), and satisfaction after TKA surgery in patients with and without prior bariatric surgery (BS).

METHODS

Scandinavian Obesity Surgery Registry (SOReg) and the Swedish Knee Arthroplasty Register (SKAR) were used to identify patients operated on with primary TKA for osteoarthritis (OA) between 2009 and 2019 that had a BS within 2 years before the TKA (BS group). These patients were compared to patients with TKA without prior BS (no BS group). The patients filled in the Knee injury and Osteoarthritis Outcome Score (KOOS) preoperatively and one year postoperatively as well as satisfaction with the surgery one year postoperatively. Multiple linear regression analysis was used to evaluate 1-year postoperative KOOS pain and ADL function between the 2 groups. Adjustments were made for sex, age, and preoperative KOOS pain and ADL function respectively.

RESULTS

Forty-four patients were included in the BS group and 3,525 patients in the no BS group. We found no statistically or clinically significant difference in one-year postoperative KOOS pain and ADL function between the BS group and the no BS group. The majority of the patients in both groups were classified as satisfied or very satisfied one year postoperatively to the TKA.

CONCLUSIONS

Our results indicate that patients without BS prior to the TKA gain similar 1-year outcome in pain, ADL function and satisfaction as patients with prior BS.

Effects of Sarcopenic Obesity and Its Confounders on Knee Range of Motion Outcome after Total Knee Replacement in Older Adults with Knee Osteoarthritis: A Retrospective Study

Sarcopenic obesity is closely associated with knee osteoarthritis (KOA) and has high risk of total knee replacement (TKR). In addition, poor nutrition status may lead to sarcopenia and physical frailty in KOA and is negatively associated with surgery outcome after TKR. This study investigated the effects of sarcopenic obesity and its confounding factors on recovery in range of motion (ROM) after total knee replacement (TKR) in older adults with KOA. A total of 587 older adults, aged ≥60 years, who had a diagnosis of KOA and underwent TKR, were enrolled in this retrospective cohort study. Sarcopenia and obesity were defined based on cutoff values of appendicular mass index and body mass index for Asian people. Based on the sarcopenia and obesity definitions, patients were classified into three body-composition groups before TKR: sarcopenic-obese, obese, and non-obese. All patients were asked to attend postoperative outpatient follow-up admissions. Knee flexion ROM was measured before and after surgery. A ROM cutoff of 125 degrees was used to identify poor recovery post-surgery. Kaplan-Meier curve analysis was performed to measure the probability of poor ROM recovery among study groups. Cox multivariate regression models were established to calculate the hazard ratios (HRs) of postoperative poor ROM recovery, using potential confounding factors including age, sex, comorbidity, risk of malnutrition, preoperative ROM, and outpatient follow-up duration as covariates. Analyses results showed that patients in the obese and sarcopenic-obese groups had a higher probability of poor ROM recovery compared to the non-obese group (all p < 0.001). Among all body-composition groups, the sarcopenic-obese group yielded the highest risk of postoperative physical difficulty (adjusted HR = 1.63, p = 0.03), independent to the potential confounding factors. Sarcopenic obesity is likely at the high risk of poor ROM outcome following TKR in older individuals with KOA.

Improvements in functional outcome and quality of life are not sustainable for patients ≥ 68 years old 10 years after total knee arthroplasty

PURPOSE

The aims of this study are to evaluate whether improvements in functional outcome and quality of life are sustainable 10 years after total knee arthroplasty (TKA), and the age cut-off for clinical deterioration in outcomes METHODS: Prospectively collected registry data of 120 consecutive patients who underwent TKA at a tertiary hospital in 2006 was analysed. All patients were assessed at 6 months, 2 years and 10 years using the Knee Society Function Score, Knee Society Knee Score, Oxford Knee Score, Short-Form 36 Physical/Mental Component Scores and postoperative satisfaction. One-way ANOVA was used to compare continuous variables, while Chi-squared test to compare categorical variables. Multivariate logistic regression and receiver operating curve analysis was performed to evaluate the predictive factors associated with deterioration of scores postoperatively.

RESULTS

Significant improvements were noted in all functional outcome and quality of life scores at 6 months after TKA. Between 6 months and 2 years, the KSFS and OKS continued to improve but the KSKS, PCS and MCS plateaued. Between 2 and 10 years, there was a deterioration in the KSFS and OKS, whilst KSKS, PCS and MCS were maintained. Increasing age was noted to be a significant risk factor for deterioration of KSFS at 10 years with age ≥ 68 as the cut-off value. 91.7% of patients with KSFS Minimally Clinically Important Difference(MCID) (≥ 7 points) continued to be satisfied after 10 years compared to 100.0% who did not experience KSFS MCID deterioration (p = 0.02).

CONCLUSION

Patients ≥ 68 years experience deterioration in functional outcomes and quality of life from 2 to 10 years after TKA.

LEVEL OF EVIDENCE

Retrospective study, Level III.

Fast Return to Sports and High Level of Activity after Cementless Oxford Unicompartmental Knee Arthroplasty

Physical activity is essential for overall health. For patients undergoing knee arthroplasty, questions about the implant's suitability for sports arise. The general recommendations for physical activity with knee replacements are often based upon experts' opinions, with a lack of scientific data. This study was performed at an independent high-volume center and aimed to investigate what level of activity patients can achieve and how they perform with a well-functioning cementless unicompartmental knee replacement (UKR). Possible differences in outcome in regards to patients' body mass index (BMI) were also examined. A total of 228 knees treated with cementless Oxford UKR (OUKR) were followed up after a mean of 37.1 months. Tegner's and UCLA (University of California, Los Angeles) scores were obtained to assess the level of physical activity. The Schulthess Clinical Activity Questionnaire was assessed for detailed information on practiced sports, and the SF-36 questionnaire was evaluated to analyze patients' quality of life. The return to activity rate was 92.9%. In total, 64% of the physically active patients had already taken up sports within 3 months after surgery. Mean Tegner's score was at 3.5, and mean UCLA score was at 6.3. High impact sports were not performed very often after surgery. Higher BMI showed a negative correlation with the numbers of sports (r_sp = -0.289) as well as Tegner's (r_sp = -0.222) and UCLA (r_sp = -0.383) scores. The SF-36 scores were comparably good to those in an age-equivalent standard reference group. In conclusion, cementless OUKR allows a fast return to activity with a high level of physical exercise. Patients with increased BMI tend to practice less types of sports with decreased activity scores.

Greater risk of all-cause revisions and complications for obese patients in 3 106 381 total knee arthroplasties: a meta-analysis and systematic review

BACKGROUND

Obesity is a major public health issue and has considerable implications on outcomes of total knee arthroplasty (TKA). However, there has been conflicting evidence and conclusions on the effects of obesity on TKA. This meta-analysis compares the outcomes, complications, and peri-operative parameters of TKA in the obese (body mass index [BMI] ≥ 30 kg/m² ) versus non-obese (BMI < 30 kg/m² ) population as well as subgroup analysis of morbidly obese (BMI ≥ 40 kg/m² ) versus non-obese population.

METHODS

A meta-analysis was conducted with a multi-database search according to PRISMA guidelines on 12 September 2019. Data from all published literature meeting inclusion criteria were extracted and analysed.

RESULTS

Ninety-one studies were included, consisting of 917 447 obese and 2 188 834 non-obese TKA. Obese patients had higher risk of all-cause revisions (odds ratio [OR] = 1.15, 95% CI: 1.08-1.24, p < 0.0001), all complications (OR = 1.21, 95% CI: 1.06-1.38, p = 0.004), deep infections (OR = 1.47, 95% CI: 1.27-1.69, p < 0.0001), superficial infections (OR = 1.59, 95% CI: 1.32-1.91, p < 0.0001), wound dehiscence (OR = 1.46, 95% CI: 1.24-1.72, p < 0.0001) and readmissions (OR = 1.21, 95% CI: 1.05-1.40, p = 0.009). Subgroup analysis of morbidly obese patients revealed greater risks of all-cause revisions (OR = 1.25, 95% CI: 1.10-1.43, p = 0.0009), deep infections (OR = 1.98, 95% CI: 1.05-3.75, p = 0.04), superficial infections (OR = 2.44, 95% CI: 2.08-2.88, p < 0.0001) and readmissions (OR = 1.33, 95% CI: 1.20-1.47, p < 0.0001). No analysis was performed on patient reported outcome measures due to heterogeneous reporting methods.

CONCLUSION

Obese and morbidly obese patients have higher risks of revisions and infections post TKA. Surgeons should counsel patients of these risks during the informed consenting process and adopt preventative strategies into clinical practice to reduce risks where possible. In conclusion, obesity is a significant, modifiable risk factor for increased complications following TKA.

Higher body mass index is associated with larger postoperative improvement in patient-reported outcomes following total knee arthroplasty

BACKGROUND

Total knee arthroplasty is known to successfully alleviate pain and improve function in endstage knee osteoarthritis. However, there is some controversy with regard to the influence of obesity on clinical benefits after TKA. The aim of this study was to investigate the impact of body mass index (BMI) on improvement in pain, function and general health status following total knee arthroplasty (TKA).

METHODS

A single-centre retrospective analysis of primary TKAs performed between 2006 and 2016 was performed. Data were collected preoperatively and 12-month postoperatively using WOMAC score and EQ-5D. Longitudinal score change was compared across the BMI categories identified by the World Health Organization.

RESULTS

Data from 1565 patients [mean age 69.1, 62.2% women] were accessed. Weight distribution was: 21.2% BMI < 25.0 kg/m2, 36.9% BMI 25.0-29.9 kg/m2, 27.0% BMI 30.0-34.9 kg/m2, 10.2% BMI 35.0-39.9 kg/m2, and 4.6% BMI ≥ 40.0 kg/m2. All outcome measures improved between preoperative and 12-month follow-up (p < 0.001). In pairwise comparisons against normal weight patients, patients with class I-II obesity showed larger improvement on the WOMAC function and total score. For WOMAC pain improvements were larger for all three obesity classes.

CONCLUSIONS

Post-operative improvement in joint-specific outcomes was larger in obese patients compared to normal weight patients. These findings suggest that obese patients may have the greatest benefits from TKA with regard to function and pain relief one year post-op. Well balanced treatment decisions should fully account for both: Higher benefits in terms of pain relief and function as well as increased potential risks and complications. Trial registration This trial has been registered with the ethics committee of Eastern Switzerland (EKOS; Project-ID: EKOS 2020-00,879).

Periprosthetic Tissue Reaction Independent of LTT Result and Implanted Materials in Total Knee Arthroplasty

BACKGROUND

An allergic reaction may rarely cause a painful or stiff total knee arthroplasty (TKA). However, no consensus diagnostic criteria for TKA immune failure exist. Lymphocyte transformation testing (LTT) measures immune sensitivity to various materials, but its role in diagnosing an allergic reaction to a TKA has not been established. This study compares TKA periprosthetic tissues in a) LTT-positive versus -negative patients and b) patients with conventional CoCrNi versus hypoallergenic implants.

METHODS

Periprosthetic tissues from 26 revision cases of well-fixed, aseptic, but painful or stiff TKAs were analyzed. Twelve patients LTT positive for nickel (Ni) were matched as a cohort to 6 LTT-negative patients. In 4 patients LTT positive for Ni, tissue from first revision of CoCrNi implants was compared with tissue from subsequent revision of hypoallergenic implants. Histology was evaluated using the aseptic lymphocyte-dominated vasculitis-associated lesion (ALVAL) score.

RESULTS

No correlation was found between LTT and any ALVAL score component. The mean total ALVAL score was 3.8 ± 1.5 for LTT-negative patients and 3.3 ± 1.2 for LTT-positive patients (P = .44). The mean total ALVAL score at revision of CoCrNi implants was 3.0 ± 1.8 compared with 5.8 ± 0.5 at rerevision of hypoallergenic implants (P = .053).

CONCLUSION

Periprosthetic TKA tissue reactions were indistinguishable between LTT-positive and -negative patients. LTT does not predict the periprosthetic tissue response. ALVAL scores of hypoallergenic revision implant tissue trended higher than primary CoCrNi implant tissue. A positive LTT may not indicate that a periprosthetic immune reaction is the cause of pain and stiffness after TKA.

LEVEL OF EVIDENCE

3, retrospective cohort study.

A clinical prediction rule for predicting a delay in quality of life recovery at 1 month after total knee arthroplasty: A decision tree model

BACKGROUND

There is no clinical prediction rule for predicting the prognosis of quality of life after total knee arthroplasty and for assessing its accuracy. The study aimed to develop and assess a clinical prediction rule to predict decline in quality of life at 1 month after total knee arthroplasty.

METHODS

This study included 116 patients with total knee arthroplasty in Japan. Potential predictors such as sociodemographic factors, medical information, and motor functions were measured. Quality of life was measured using the Japanese Knee Osteoarthritis Measure at 1 day before surgery and 1 month after total knee arthroplasty. The classification and regression tree methodology was used for developing a clinical prediction rule.

RESULTS

The Japanese Knee Osteoarthritis Measure score pre-total knee arthroplasty (≦34.0 or >34.0) was the best single discriminator. Among those with the Japanese Knee Osteoarthritis Measure score pre-total knee arthroplasty ≦34.0, the next best predictor was knee flexor muscle strength on the affected side (≦0.45 or >0.45 N m/kg). Among those with knee flexor muscle strength on the affected side >0.45, the next predictor was knee flexion range of motion on the affected side (≦132.5°or >132.5°). The area under the receiver operating characteristic curves of the model was 0.805 (95% confidence interval, 0.701-0.909).

CONCLUSIONS

In this study, 4 variables were selected as the significant predictor. However, the results of knee flexor muscle strength and knee flexion range of motion were paradoxical. This result suggests that it should be careful to perform surgery to the patients with good preoperative knee function. The clinical prediction rule was developed for predicting quality of life decline 1 month after total knee arthroplasty, and the accuracy was moderate. This clinical prediction rule can be used for screening of patients with total knee arthroplasty.

Long-Term Functional Outcomes and Quality of Life at Minimum 10-Year Follow-Up After Fixed-Bearing Unicompartmental Knee Arthroplasty and Total Knee Arthroplasty for Isolated Medial Compartment Osteoarthritis

BACKGROUND

The aim of this study is to compare the long-term functional outcome and quality of life between total knee arthroplasty (TKA) and fixed-bearing unicompartmental knee arthroplasty (UKA) for the treatment of isolated medial compartment osteoarthritis.

METHODS

Between 2000 and 2008, a total of 218 patients underwent primary UKA at our tertiary hospital. A TKA group was matched through 1:1 propensity score matching and adjusted for age, gender, body mass index, preoperative knee flexion, and function scores. All patients had medial compartment osteoarthritis. The patients were assessed with the range of motion, Knee Society Knee Score and Knee Society Function Score, Oxford Knee Score, Short Form-36 physical component score (PCS) and mental component score preoperatively, at 6 months, 2 years, and 10 years. Patients' satisfaction, expectation fulfillment, and minimal clinically important difference were analyzed.

RESULTS

There were no differences in baseline characteristics between groups after propensity score matching (P > .05). UKA had greater knee flexion at all time points. Although the Knee Society Function Score was superior in UKA by 5.5, 3, and 4.3 points at 6 months, 2 years, and 10 years, respectively (P < .001), these differences did not exceed the minimal clinically important difference (Knee Society Knee Score 6.1). There were no significant differences in the Oxford Knee Score and Short Form-36 physical component score/mental component score. At 10 years, similar proportions of UKA and TKA were satisfied (90.8% vs 89.9%, P = .44) and had expectation fulfillment (89.4% vs 88.5%, P = .46). Between 2 and 10 years, all function scores deteriorated significantly for both groups (P < .01).

CONCLUSION

UKA and TKA are excellent treatment modalities for isolated medial compartment osteoarthritis, with similar functional outcomes, quality of life, and satisfaction at 10 years.

The relationship between obesity and primary Total Knee Replacement: A scoping review of the literature

BACKGROUND

Primary Total Knee Replacement (TKR) is one of the most commonly performed elective orthopaedic procedures globally. Many patients undergoing this type of surgery are overweight or obese. In the UK, clinical commissioning groups have imposed arbitrary Body Mass Index (BMI) thresholds for TKR surgery. Many obese patients undergoing TKR believe they will lose weight following the procedure because of increased mobility.

AIM

This paper aims to present the findings of a scoping literature review about the relationship between obesity and primary TKR and to make recommendations for clinical practice, education and policy.

METHODS

A scoping literature review investigated the impact of BMI/body weight on the need for TKR, the impact of body weight and or BMI on patient outcomes following TKR, weight loss/gain following TKR and the implications of obesity on cost of TKR.

FINDINGS

Seventy-one papers were included in the review. Seven studies reported statistically significant associations between increased BMI/obesity with the need for TKR. Thirty of the studies reported worse outcomes for obese patients compared to non-obese comparisons. Forty of the studies reported no difference between obese and non-obese participants, including some where outcomes of obese patients were better than non-obese comparisons. Eight studies reported on changes to weight before and after TKR, three of the studies reporting a higher percentage losing weight than gaining weight and four studies reporting that obese patients gained weight. The 8th study reported that morbidly obese patients largely returned to their baseline BMI postoperatively.

CONCLUSION

The findings of the review challenge the legitimacy of setting BMI thresholds to control access to TKR surgery. There is an urgent need to develop evidence based approaches to support weight loss and weight management for this group of patients. Obese patients undergoing TKR should receive specific information regarding potential additional risks of complications and poorer outcomes. There is a need for health promotion regarding the association of being overweight/obese in young adulthood and developing osteoarthritis of the knee joints requiring TKR in middle and older age.

No influence of obesity on mid-term clinical, functional, and radiological results after computer-navigated total knee arthroplasty using a gap balancing technique

OBJECTIVE

In obese patients, thick subcutaneous tissue can introduce errors during registration and leg weight can influence gap balancing in navigated TKA. Present study is done to determine if computer navigated TKA using a gap balancing technique can achieve consistent accuracy for limb and component alignment, and similar clinical and functional results in obese patients like in non-obese patients.

METHODS

We prospectively compared the radiological, clinical, and functional results of 78 knees in 57 non-obese patients and 79 knees in 58 obese patients who underwent computer-assisted TKA. Non-obese individuals were defined as those having BMI of <30 kg/m² and obese individuals as BMI ≥30 kg/m². The degree of knee deformity was calculated by Hip - Knee - Ankle (HKA) angle and clinical and functional assessment was done using the Knee Society Score - clinical knee score and Knee Society Score - function score, respectively. All these were documented before and at 6 months, 2 year, and 5 years after TKA.

RESULTS

The outlier rate of postoperative limb alignment (HKA angle) was 8.9% in the obese group which was not significantly different (p =1.00) from that of the non-obese group (7.7%). Mean clinical knee scores were not significantly different between the non-obese and obese groups preoperatively (58.8 vs 57.4, p = 0.14) and at 6 months (92.7 vs 91, p = 0.06), 2 years (91.4 vs 90, p = 0.07), and 5 years (92.4 vs 91.3, p = 0.1) post-surgery. Similarly, mean functional scores were not significantly different between the non-obese and obese groups preoperatively (50.9 vs 49.9, p = 0.31) and at 6 months (92.7 vs 90.9, p = 0.06), 2 years (91.3 vs 92, p = 0.44), and 5 years (90.6 vs 91.1, p = 0.51) post-surgery.

CONCLUSION

Obesity has no influence on mid-term clinical, functional, and radiological results after computer navigated TKA, done by gap balancing technique.

LEVEL OF EVIDENCE

Therapeutic level II.

Predictive value of adipose to muscle area ratio based on MRI at knee joint for postoperative functional outcomes in elderly osteoarthritis patients following total knee arthroplasty

BACKGROUND

The current research used a new index-adipose to muscle area ratio (AMR)-to measure fatness compared with body mass index (BMI) in elderly osteoarthritis (OA) patients following total knee arthroplasty. Our study aimed to test the relationship between the two indexes (AMR and BMI) and to examine whether AMR was a predictive factor of patient-reported outcome measures (PROMS) for elderly OA patients following total knee arthroplasty (TKA).

METHODS

The retrospective data of 78 OA patients (older than 60 years) following TKA was included in our study. Clinical features of patients included age, BMI, sex, AMR, side of the implant, time of follow-up, complications, the Knee Society Score (KSS score), and the Hospital for Special Surgery knee score (HSS score). The area of adipose tissue and muscle tissue was measured on the cross section (supra-patella, midline of the patella, joint line of the knee) of the knee magnetic resonance imaging (MRI). AMR was calculated as the average of adipose to muscle area ratio at the three levels. The Pearson correlation analysis, simple linear regression, and multiple linear regression were used to study the relationship between BMI, AMR, and PROMS (KSS total-post score and HSS-post score) in the study.

RESULTS

Of all patients, the mean (± standard deviations (SD)) of age was 67.78 ± 4.91 years. For BMI and AMR, the mean (± SD) were 26.90 ± 2.11 and 2.36 ± 0.69, respectively. In Pearson correlation analysis, BMI had a good correlation with AMR (r = 0.56, p = 0.000), and AMR (r = - 0.37, p = 0.001, HSS-post score; r = - 0.43, p = 0.000, KSS total-post score) had better correlations with PROMS postoperatively compared with BMI (r = - 0.27, p = 0.019, HSS-post score; r = - 0.33, p = 0.003, KSS total-post score). In multivariate linear regression analysis, AMR was negatively correlated with KSS total-post score as well as HSS-post score, while BMI was not. As for patients with complications, AMR values were between the 3rd quartile and 4th quartile of the AMR value in the entire study cohort.

CONCLUSIONS

In this study, the new obesity evaluation indicator-AMR, which was well related with BMI, was found to be a predictor of PROMS (KSS total-post score and HSS-post score) in elderly OA patients following TKA.

Does Multimodal Therapy Influence Functional Outcome After Total Knee Arthroplasty?

Psychosocial health may influence the outcomes after total knee arthroplasty (TKA). We investigated the hypothesis that multimodal therapy influences the quality of life and function in patients diagnosed with osteoarthritis of the knee joint. Secondly, in patients who then proceed to have TKA post-multimodal therapy, does the response to the multimodal therapy influence the overall functional outcome of surgery? Patients diagnosed with osteoarthritis of the knee were enrolled in the study and prospectively followed-up. A total of 526 patients were enrolled and available for the study. All participants were enrolled for 12 classes of 60-minute duration over 6-weeks. Apart from an exercise program, the class also included physiotherapist-led education and a 'weight management' lecture by a dietitian. In summary, the multimodal therapy program improved the SF-12, OKS, pain scores (visual analogue scale) and WOMAC scores significantly. The multimodal therapy protocol can optimize patients' psychological scores prior to TKA and may enhance ultimate functional outcome.

Physical Therapist Management of Total Knee Arthroplasty

A clinical practice guideline on total knee arthroplasty was developed by an American Physical Therapy (APTA) volunteer guideline development group that consisted of physical therapists, an orthopedic surgeon, a nurse, and a consumer. The guideline was based on systematic reviews of current scientific and clinical information and accepted approaches to management of total knee arthroplasty.

Preoperative vitamin D level does not affect the short-term functional outcome after total knee arthroplasty in elderly women

Background

We aimed to evaluate the effect of vitamin D levels on the functional outcome of elderly women who underwent total knee arthroplasty (TKA).

Methods

Seven hundred and four patients (1013 knees) who underwent primary TKA were included in our retrospective study. Preoperative vitamin D levels were measured and the relationship analyzed between these and age, weight, height, body mass index, and bone mineral density. Two hundred and twenty patients (220 knees) who received unilateral TKA and were followed up for more than 1 year after operation were divided into two groups: Group 1, serum 25-hydroxyvitamin D3 (25(OH)D3) level < 20 ng/ml; and Group 2, 25(OH)D3 level ≥ 20 ng/ml. Both groups were evaluated for the relationship between vitamin D levels and postoperative Visual Analogue Scale (VAS) score, Knee Society Knee Score (KSKS), Knee Society Function Score (KSFS), and Western Ontario and McMaster Universities Arthritis Index (WOMAC) score.

Results

The number of vitamin D-deficient patients (< 20 ng/ml of serum 25(OH)D3 level) was 556 (79.0%). In the correlation analysis, the vitamin D level was negatively correlated with weight only (p = 0.033). No significant differences were observed between the groups in terms of postoperative VAS score, KSKS, KSFS, and WOMAC score.

Conclusions

Vitamin D deficiency was highly prevalent in patients who underwent TKA. Vitamin D levels negatively correlated with weight. Low vitamin D level was not a risk factor for unsatisfactory TKA outcome in elderly women.

Mental Health and Tobacco Use Are Correlated With Physical Function Outcomes in Patients With Knee Pain and Injury

PURPOSE

To examine the relation between the Patient-Reported Outcomes Measurement Information System (PROMIS) domains of Pain Interference (PROMIS-PI), Depression (PROMIS-D), and Physical Function (PROMIS-PF) for nonoperative patients presenting to our ambulatory sports orthopaedic clinic with knee complaints and to determine whether patient demographic characteristics influence PROMIS scores, particularly tobacco use.

METHODS

All patients treated nonoperatively for a primary complaint of knee pain were recruited for participation. Patients were included if they completed all 3 PROMIS questionnaires prior to their clinical evaluation. Patients were excluded if their treatment plan determined that surgical intervention was warranted. Survey results were compiled, and statistical correlations were run between PROMIS domains and patient demographic characteristics.

RESULTS

A total of 527 PROMIS questionnaire sets were included. PROMIS-PF had a strong negative correlation with PROMIS-PI (R = -0.75, P < .001) and a nearly moderate negative correlation with PROMIS-D (R = -0.47, P < .001). When evaluating patient demographic characteristics, we found a significant decrease in physical function scores and increases in pain and depression scores in both current and former tobacco users compared with nonsmokers. Differences in all PROMIS domains between smokers and nonsmokers exceeded minimal clinically important differences.

CONCLUSIONS

Our study showed an inverse correlation between PROMIS-PI and PROMIS-PF, as well as between PROMIS-D and PROMIS-PI, in patients seen in the ambulatory setting for knee complaints treated nonoperatively. A positive correlation was found between PROMIS-PI and PROMIS-D. Tobacco use was a patient demographic factor found to significantly impact PROMIS scores leading to minimal clinically important differences across all 3 PROMIS domains. The findings of this study may be used to identify patients at high risk of poor outcomes.

LEVEL OF EVIDENCE

Level III, observational study.

Minimal Clinically Important Difference of Oxford, Constant, and UCLA shoulder score for arthroscopic rotator cuff repair

Aim

To determine the Minimal Clinically Important Difference (MCID) for Constant-Murley score (CMS), University of California Los Angeles (UCLA) shoulder score, and Oxford Shoulder Scores (OSS) after arthroscopic rotator cuff (RC) repairs.

Material and methods

306 patients were followed up for 24-month. MCID for CMS, UCLA and OSS were determined using simple linear regression according to patient satisfaction and expectation fulfilment.

Results

The following MCID were identified:12-month: CMS 6.7, UCLA 3.0, OSS 3.3.24-month: CMS 6.3, UCLA 2.9, OSS 2.7.

Conclusions

The various MCID could assist in meaningful interpretation of these scores and to power future comparative studies.

Level of evidence

III.

Unicondylar Tibiofemoral Arthroplasty - Opinions of the Members of the German Knee Society (DKG) and the German Professional Association of Orthopaedic and Trauma Specialists (BVOU)

BACKGROUND

The number of implanted unicondylar tibiofemoral knee arthroplasties (UKA) is despite the potential advantages in comparison to total knee arthroplasties (TKA) in Germany relatively low. Goal of this survey, initiated by the Small Implants Group of the German Knee Society, was to gather opinions and put them into context of the current literature.

METHODS

Based on the Delphi method and the AWMF rules and standards, 19 statements were developed, which were presented to the members of the DKG and BVOU in an anonymous online survey using "SurveyMonkey". Overall, 410 colleagues participated.

RESULTS

The biggest detected controversies were the determination of indications with respect to the body mass index and the existence of a patellofemoral arthrosis. A general consent was determined that a contralateral tibiofemoral arthrosis grade III - IV and meniscal deficiency in the contralateral compartment are an absolute contraindication. There was a consent that age is not a limitation for the implantation of an UKA. If a personal minimum volume of 15 implantations/year should be implemented was seen controversial.

CONCLUSION

The personal opinion, eventually built by personal experiences, appears to be in conflict with the knowledge of scientific literature in many instances. Intensive training and education appears necessary.

What are the implications of withholding total joint arthroplasty in the morbidly obese?

Aims

The aim of this study was to observe the implications of withholding total joint arthroplasty (TJA) in morbidly obese patients

Patients and Methods

A total of 289 morbidly obese patients with end-stage osteoarthritis were prospectively followed. There were 218 women and 71 men, with a mean age of 56.3 years (26.7 to 79.1). At initial visit, patients were given information about the risks of TJA in the morbidly obese and were given referral information to a bariatric clinic. Patients were contacted at six, 12, 18, and 24 months from initial visit.

Results

The median body mass index (BMI) at initial visit was 46.9 kg/m2 (interquartile range (IQR) 44.6 to 51.3). A total of 82 patients (28.4%) refused to follow-up or answer phone surveys, and 149 of the remaining 207 (72.0%) did not have surgery. Initial median BMI of those 149 was 47.5 kg/m2 (IQR 44.6 to 52.5) and at last follow-up was 46.7 kg/m2 (IQR 43.4 to 51.2). Only 67 patients (23.2%) went to the bariatric clinic, of whom 14 (20.9%) had bariatric surgery. A total of 58 patients (20.1%) underwent TJA. For those 58, BMI at initial visit was 45.3 kg/m2 (IQR 43.7 to 47.2), and at surgery was 42.3 kg/m2 (IQR 38.1 to 46.5). Only 23 patients (39.7%) of those who had TJA successfully achieved BMI < 40 kg/m2 at surgery.

Conclusion

Restricting TJA for morbidly obese patients does not incentivize weight loss prior to arthroplasty. Only 20.1% of patients ultimately underwent TJA and the majority of those remained morbidly obese. Better resources and coordinated care are required to optimize patients prior to surgery. Cite this article: Bone Joint J 2019;101-B(7 Supple C):28–32

Management of the Bariatric Patient. What Are the Implications of Obesity and Total Joint Arthroplasty: The Orthopedic Surgeon's Perspective?

BACKGROUND

Obesity in the United States has reached epidemic proportions. It is associated with multiple higher rates of osteoarthritis of the hip and knee and thus an increasing need for total hip and knee arthroplasty. The demand for total joint arthroplasty among obese patients has increased and outpaces that of a non-obese cohort. The complications associated with obese patients undergoing hip or knee replacement is well defined in the literature.

METHODS

Many practices have set restriction on body mass index (BMI) prior to elective total join arthroplasty. We review the implications of these BMI cutoffs as it is related to access to care for morbidly obese patients in need of hip and knee arthroplasty.

RESULTS

Of the 289 patients who presented with BMI >40, only 19% of patients underwent total hip or knee arthroplasty at a minimum of 2 years of follow-up.

CONCLUSION

This symposium discusses the implications of withholding surgery in the morbidly obese and sets the stage for the development of more collaborative work to ensure optimal care and optimal outcome for the morbidly obese.

The influence of obesity on clinical outcomes of fixed-bearing unicompartmental knee arthroplasty

Aims

The aim of this study was to assess the influence of obesity on the clinical outcomes and survivorship ten years postoperatively in patients who underwent a fixed-bearing unicompartmental knee arthroplasty (UKA).

Patients and Methods

We prospectively followed 184 patients who underwent UKA between 2003 and 2007 for a minimum of ten years. A total of 142 patients with preoperative body mass index (BMI) of < 30 kg/m2 were in the control group (32 male, 110 female) and 42 patients with BMI of ≥ 30 kg/m2 were in the obese group (five male, 37 female). Pre- and postoperative range of movement (ROM), Knee Society Score (KSS), Oxford Knee Score (OKS), 36-Item Short-Form Health Survey (SF-36), and survivorship were analyzed.

Results

Patients in the obese group underwent UKA at a significantly younger mean age (56.5 years (sd 6.4)) than those in the control group (62.4 years (sd 7.8); p < 0.001). There was no significant difference in preoperative functional scores. However, those in the obese group had a significantly lower ROM (116° (sd 15°) vs 123° (sd 17°); p = 0.003). Both groups achieved significant improvement in outcome scores regardless of BMI, ten years postoperatively. All patients achieved the minimal clinically important difference (MCID) for OKS and KSS. Both groups also had high rates of satisfaction (96.3% in the control group and 97.5% in the obese group) and the fulfilment of expectations (94.9% in the control group and 95.0% in the obese group). Multiple linear regression showed a clear association between obesity and a lower OKS two years postoperatively and Knee Society Function Score (KSFS) ten years postoperatively. After applying propensity matching, obese patients had a significantly lower KSFS, OKS, and physical component score (PCS) ten years postoperatively. Seven patients underwent revision to total knee arthroplasty (TKA), two in the control group and five in the obese group, resulting in a mean rate of survival at ten years of 98.6% and 88.1%, respectively (p = 0.012).

Conclusion

Both groups had significant improvements in functional and quality-of-life scores postoperatively. However, obesity was a significant predictor of poorer improvement in clinical outcome and an increased rate of revision ten years postoperatively.

Predicting patient-reported outcomes following hip and knee replacement surgery using supervised machine learning

BACKGROUND

Machine-learning classifiers mostly offer good predictive performance and are increasingly used to support shared decision-making in clinical practice. Focusing on performance and practicability, this study evaluates prediction of patient-reported outcomes (PROs) by eight supervised classifiers including a linear model, following hip and knee replacement surgery.

METHODS

NHS PRO data (130,945 observations) from April 2015 to April 2017 were used to train and test eight classifiers to predict binary postoperative improvement based on minimal important differences. Area under the receiver operating characteristic, J-statistic and several other metrics were calculated. The dependent outcomes were generic and disease-specific improvement based on the EQ-5D-3L visual analogue scale (VAS) as well as the Oxford Hip and Knee Score (Q score).

RESULTS

The area under the receiver operating characteristic of the best training models was around 0.87 (VAS) and 0.78 (Q score) for hip replacement, while it was around 0.86 (VAS) and 0.70 (Q score) for knee replacement surgery. Extreme gradient boosting, random forests, multistep elastic net and linear model provided the highest overall J-statistics. Based on variable importance, the most important predictors for post-operative outcomes were preoperative VAS, Q score and single Q score dimensions. Sensitivity analysis for hip replacement VAS evaluated the influence of minimal important difference, patient selection criteria as well as additional data years. Together with a small benchmark of the NHS prediction model, robustness of our results was confirmed.

CONCLUSIONS

Supervised machine-learning implementations, like extreme gradient boosting, can provide better performance than linear models and should be considered, when high predictive performance is needed. Preoperative VAS, Q score and specific dimensions like limping are the most important predictors for postoperative hip and knee PROMs.

Association between preoperative anaemia and blood transfusion with long-term functional and quality of life outcomes amongst patients undergoing primary total knee arthroplasty in Singapore: a single-centre retrospective study

PURPOSE

Preoperative anaemia affects up to one-third of patients undergoing total knee arthroplasty (TKA) and is associated with increased blood transfusion and prolonged hospitalisation. Prior studies have associated preoperative anaemia with poorer functional recovery after total hip arthroplasty. However, the association between preoperative anaemia and functional outcomes following TKA is unknown. We aim to determine whether preoperative anaemia and perioperative blood transfusion affect health-related quality of life (HRQoL) and functional outcomes following TKA.

METHODS

Retrospective analysis of 1994 patients who underwent primary unilateral TKA from 2013 to 2014 was performed. Anaemia was defined according to the World Health Organisation definition. Baseline and 6-month postoperative HRQoL was assessed with the 36-Item Short Form Survey (SF-36), while function was assessed with Oxford Knee Score (OKS) and Knee Society Function Score (KSFS). Physical function (PF), role physical (RP), bodily pain (BP), social function (SF) and role emotional (RE) domains of SF-36, OKS and KSFS demonstrated significant change greater than the minimal clinically important difference between baseline and 6 months. Analysis of covariance (ANCOVA) was performed to identify predictors of 6-month scores.

RESULTS

The incidence of preoperative anaemia was 22.3%. 4.3% of patients received blood transfusions. Preoperative anaemia and perioperative blood transfusion did not significantly affect SF-36, KSFS and OKS scores at 6 months postoperatively. Poor baseline SF-36, KSS and OKS scores and high BMI ≥ 37.5 kg/m² are consistently associated with lower scores at 6 months.

CONCLUSION

Preoperative anaemia and perioperative blood transfusion did not significantly affect HRQoL and functional outcomes following primary TKA. Poor baseline and obesity were associated with poorer outcomes.