NIH Consensus Statement on Total Knee Replacement December 8-10, 2003*:

A Pilot Study on the Efficacy of an App-Based Rehabilitation Counselling Program after Total Knee Arthroplasty

The aim of this study was to determine the effects of a novel app-based rehabilitation counselling program in patients recovering from total knee arthroplasty. In the app-based rehabilitation counselling program, a counselor provides one-on-one rehabilitation exercises and management-focused psychological counselling after total knee arthroplasty (TKA). This study included 42 patients, who were divided into three groups of 14 patients each: Group A, whose rehabilitation training was based on a guideline leaflet; Group B, whose rehabilitation was based on the app-based rehabilitation counselling program; and Group C, whose rehabilitation training was based on continuous passive motion combined with the app-based rehabilitation counselling program. To determine the effects of rehabilitation, the isokinetic knee muscle strength and knee joint range of motion were measured in addition to knee function tests such as the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the visual analogue scale (VAS) for pain at two and three months after rehabilitation. The comparison of the means of the three groups was analyzed using one-way analysis of variance (ANOVA), with Group C showing significant variance in isokinetic knee muscle strength (p < 0.05), passive ROM (p < 0.01), and WOMAC (p < 0.05) after three months. As a result, this study confirmed the positive potential of the app-based rehabilitation counselling program.

The Vega advanced third generation posterior stabilized total knee arthroplasty system enables the restoration of range of motion for high demanding daily activities - A 5-years follow-up study

BACKGROUND

The Vega System® PS (Aesculap AG, Tuttlingen, Germany) is an advanced, third generation fixed implant that aims to mimic natural knee kinematics by optimizing pivotal motion while reducing surface stress. This study evaluated mid-term survival and clinical outcomes, including range of motion (ROM) of the modern posterior stabilized implant in order to analyse whether this biomechanically successful implant reaches good results in situ.

METHODS

The first 100 patients to receive the Vega PS System for total knee arthroplasty were invited to take part in this single centre, single surgeon study. Of these, 84 patients were clinically assessed 5-6 years postoperatively. Data which was obtained during this follow-up examination included revision data, range of motion and clinical scores.

RESULTS

The 5-year survival rate for exchange of any component was 97.6%, whereby two patients required replacement of the polyethylene gliding surface. Secondary patella resurfacing was performed in 7 patients. Significantly improved results in comparison to the preoperative state could be obtained at the follow-up: KOOS improved from 39.4 to 78.8, SF-12 PCS improved from 32.1 to 42 SF-12 MCS improved from 46 to 53.8 and patella pain improved from 2.7 to 0.3. The mean ROM of the 84 patients after 5 years was 133.1° and mean total KSS was 189.9.

DISCUSSION & CONCLUSIONS

This study demonstrates a high survival rate of the Vega PS System® and significant improvements in clinical outcomes 5 years after implantation. The obtained mean ROM indicates that this implant provides good flexibility of the knee joint, allowing a high number of activities. However, due to the rate of secondary patella implantation, routine resurfacing of the patella for all PS TKA cases is highly recommended.

CLINICAL TRIALS REGISTRATION

The study was registered at clinicaltrials.gov (NCT02802085).

Early Versus Late Periprosthetic Joint Infection After Total Knee Arthroplasty: Do Patient Differences Exist?

BACKGROUND

Periprosthetic joint infection (PJI) is a devastating complication following total knee arthroplasty (TKA). Little evidence exists comparing those with early versus late PJI. The purpose of the study was to determine comorbidity profile differences between patients developing early and late PJI.

METHODS

There were 72,659 patients undergoing primary TKA from 2009 to 2021, who were identified from a commercial claims and encounters database. Subjects diagnosed with PJI were categorized as either 'early' (within 90 days of index procedure) or 'late' (> 2 years after index arthroplasty). Non-infected patients within these periods served as control groups following 4:1 propensity score matching on other extraneous variables. Logistic regression analyses were performed comparing comorbidities between groups.

RESULTS

Patients were significantly younger in the late compared to the early infection group (58.1 versus 62.4 years, P < .001). When compared to those with early PJI, patients who had chronic kidney disease (13.3 versus 4.1%; OR [odds ratio] 5.17, P = .002), malignancy (20.4 versus 10.5%; OR 2.53, P = .009), uncomplicated diabetes (40.8 versus 30.6%; OR 2.00, P = .01), rheumatoid arthritis (9.2 versus 3.3%; OR 2.66, P = .046), and hypertension (88.8 versus 81.6%; OR 2.17, P = .04), were all significant predictors of developing a late PJI.

CONCLUSIONS

When compared to patients diagnosed with early PJI following primary TKA, the presence of chronic kidney disease, malignancy, uncomplicated diabetes, rheumatoid arthritis, and hypertension, were independent risk factors for the development of late PJI. Younger patients who have these comorbidities may be targets for preoperative optimization interventions that minimize the risk of PJI.

Marital Status, Race, Insurance Type, and Socioeconomic Status-Assessment of Social Predictors for Outcomes After Total Knee Arthroplasty

BACKGROUND

The purpose of this study was to investigate the effect of various social determinants of health on outcomes and dispositions after total knee arthroplasty (TKA).

METHODS

A retrospective review was conducted on 14,462 consecutive TKA procedures between 2013 and 2021 at a multicenter hospital system. Data abstraction was done by inquiry to the Michigan Arthroplasty Registry Collaborative Quality Initiative. Data points requested included basic demographics, marital status, race, insurance status, socioeconomic status measured by the Area of Deprivation Index, perioperative course, and incidence of emergency department (ED) visits and readmissions within 3 months of surgery. Subsequent multivariate analyses were conducted.

RESULTS

Unmarried patients required markedly greater lengths of hospital stay and had an increased rate of discharge to skilled nursing facilities and a higher likelihood of any purpose ED visit within 90 days of surgery compared with married patients, who had a significantly greater rate of same-day discharge ( P < 0.001). Race did not markedly correlate with outcomes. Medicare patients showed a greater rate of same-day discharge, nonhome discharge, and 90-day ED visits compared with privately insured patients ( P < 0.001). Medicaid patients were more likely than privately insured patients to have a 90-day ED visit ( P < 0.001). Socioeconomic status had a minimal clinical effect on all studied outcomes.

CONCLUSION

Social factors are important considerations in understanding outcomes after TKA. Additional investigations are indicated in identifying at-risk patients and subsequent optimization of these patients.

Improvement in Gait Speed Affects Short-term Improvement in Activities of Daily Living in Patients with Moderate and Severe Knee Osteoarthritis

Objectives

It is unclear whether improvements in knee pain or physical function lead to improvements in activities of daily living (ADL) and quality of life (QOL) in patients with moderate to severe knee osteoarthritis (KOA). This study aimed to investigate whether improvements in knee pain and physical function, achieved through exercise therapy, lead to improvements in ADL and QOL in patients with moderate to severe KOA.

Methods

This case-control study included 18 patients with KOA. We evaluated knee range of motion, knee extension muscle strength (KEM), gait speed, knee pain, Knee Injury and Osteoarthritis Outcome Score (KOOS)-ADL, and KOOS-QOL at the first visit and after 3 months of exercise therapy. Patients were classified into the ADL and QOL improvement or no-improvement groups. Statistical analysis used split factorial analysis of variance with time and group as the main effects. When interactions were observed, post-hoc analysis was performed with two-sample t-tests.

Results

For ADL improvement, the improvements in KEM of the affected side and gait speed were statistically significant. At 3 months, the gait speed of the improvement group was significantly higher than that of the no-improvement group. For QOL improvement, there was no significant interaction for any of the factors evaluated.

Conclusions

No factor showed significant contribution to improved QOL in patients with moderate to severe KOA. However, increased gait speed may improve ADL and contribute to the development of efficient rehabilitation programs for patients with moderate to severe KOA.

Oxidative stress mediates associations between preoperative psychosocial phenotype and pain-related outcomes at 6 months following total knee arthroplasty: a longitudinal cohort study

OBJECTIVE

Greater preoperative depression, anxiety, and pain catastrophizing are associated with more severe long-term pain following total knee arthroplasty (TKA). In a secondary analysis of previously reported data, we tested the hypothesis that these associations are mediated by oxidative stress (OS).

DESIGN

A mixed between/within-subjects longitudinal cohort design.

SETTING

A single academic medical center.

SUBJECTS

Osteoarthritis patients (n = 91; 62.6% female) undergoing unilateral TKA.

METHODS

We assessed depression, anxiety, and catastrophizing, as well as markers of central sensitization (widespread pain, temporal summation of pain) preoperatively. Blood samples were then obtained immediately prior to intraoperative tourniquet placement for quantification of in vivo biomarkers of systemic OS, F2-isoprostanes and isofurans. Post-TKA pain intensity (numeric rating scale worst pain [NRS], McGill Pain Questionnaire-2 [MPQ-2]) and function (PROMIS Pain Interference) were assessed at 6 months following TKA.

RESULTS

Greater preoperative depression, catastrophizing, and widespread pain were associated with higher intraoperative combined OS (F2-isoprostanes+isofurans/2), which was in turn associated with higher post-TKA pain intensity and worse function (P < .05). All preoperative phenotype predictors except anxiety were correlated positively with post-TKA pain and/or function (P < .05). Bootstrapped mediation analyses revealed significant (P < .05) indirect (mediated) effects of depression (NRS Worst Pain, MPQ-2, PROMIS Pain Interference), anxiety (MPQ-2, PROMIS Pain Interference), and catastrophizing (PROMIS Pain Interference) on adverse long-term post-TKA outcomes via elevated OS. Central sensitization-related predictors demonstrated only direct effects (P < .05) on post-TKA outcomes that were independent of OS mechanisms.

CONCLUSIONS

Results suggest that the adverse impact of depression, anxiety, and pain catastrophizing on post-TKA pain and functional outcomes are mediated in part by elevated OS.

A Retrospective Comparison of Clinical Efficacy between Multimodal Analgesia and Patient-Controlled Epidural Analgesia in Patients Undergoing Total Knee Arthroplasty

Background and Objectives: Adequate pain management during early rehabilitation is mandatory for improving the outcomes of patients undergoing total knee arthroplasty (TKA). Conventional pain management, mainly comprising opioids and epidural analgesia, may result in certain adverse effects such as dizziness, nausea, and motor blockade. We proposed a multimodal analgesic (MA) strategy involving the use of peripheral nerve block (NB), periarticular injection (PAI), and intravenous patient-controlled analgesia (IVPCA). This study compared the clinical efficacy and adverse effects of the proposed MA strategy and patient-controlled epidural analgesia (PCEA). Materials and Methods: We enrolled 118 patients who underwent TKA under spinal anesthesia. The patients followed either the MA protocol or received PCEA after surgery. The analgesic effect was examined using a numerical rating scale (NRS). The adverse effects experienced by the patients were recorded. Results: A lower proportion of patients in the MA group experienced motor blockade (6.45% vs. 22.98%) compared to those in the PCEA group on the first postoperative day. Furthermore, a lower proportion of patients in the MA group experienced numbness (18.52% vs. 43.33%) than those in the PCEA group on the first postoperative day. Conclusions: The MA strategy can be recommended for reducing the occurrence of motor blockade and numbness in patients following TKA. Therefore, the MA strategy ensures early rehabilitation while maintaining adequate pain relief.

Cementless Total Knee Arthroplasty Over the Past Decade: Excellent Survivorship in Contemporary Designs

BACKGROUND

Cementless fixation in total knee arthroplasty (TKA) is re-emerging due to improvements in biomaterials, surgical technique, and implant design. Albeit rare, failure of osseointegration typically occurs within the first 2 years, and limited data exist on survivorship of the modern cementless TKA designs. This study evaluated clinical survivorship of 2 contemporary cementless TKA designs at minimum 2-year follow-up.

METHODS

A total of 627 cementless TKAs were performed up to July 2022. Three hundred thirty-nine cases were eligible for 2-year follow-up. Indications centered around bone quality and involved predominantly younger patients. The 2 designs consisted of tibial components with a highly porous titanium ingrowth surface, a central keel, and peripheral cruciform pegs with a porous cobalt-chromium femur. Survivorship estimates were calculated using right-censored non-parametric Kaplan-Meier methodologies. A total of 226 TKAs obtained minimum 2-year follow-up with a mean of 3.6 years (range, 2 to 10).

RESULTS

The all-cause revision rate was 2.4% (8 of 339). The revision rate due to aseptic loosening was 0.6% (2 of 339) consisting of 2 femoral components. No tibial components were revised for aseptic loosening. Kaplan-Meier survivorship free from aseptic loosening was 99% (95% confidence interval 98 to 100) at a maximum of 10 years.

CONCLUSION

These results demonstrate encouraging survivorship of cementless fixation in primary TKA with use of contemporary ingrowth biomaterials and modern implant designs. This particular tibial implant design with a highly porous titanium fixation surface, central keel, and peripheral cruciform pegs demonstrated excellent clinical survivorship without failure which may portend superior fixation.

LEVEL OF EVIDENCE

IV-case series, no control group/historical control group.

Immunohistochemical analysis of the quadriceps femoris muscle before and after total knee arthroplasty

BACKGROUND

The number of total knee arthroplasties (TKA) has increased steadily with the aging of the population. This surgical procedure is recognized for its success in pain relief and restoration of knee function. However, decreased quadriceps femoris (QF) muscle strength after TKA is frequently observed but with unknown etiology. Evidence suggests that the location of the operative incision (i.e., surgical access) can influence QF muscle structure and function. The present study aimed to assess the fiber type composition, structure and assembly of the QF's vastus medialis (VM) and vastus lateralis (VL) muscles before and after TKA.

METHODS

Muscle biopsies (VM and VL muscles) were collected from patients previously submitted to TKA via the medial parapatellar route and undergoing TKA revision (main group, n = 9) and patients with osteoarthrosis (OA) who were due to undergo TKA (control group: n = 18). The biopsied muscle tissue was prepared, stored, and then sectioned in a cryostat at -25 °C. The tissue sections were evaluated using routine staining techniques in pathological anatomy and histochemistry.

RESULTS

The normal mosaic pattern of the medial and lateral knee muscles was observed in the main and control groups, with no evidence of peripheral nerve damage. Notably, 88.9 % of the patients exhibited mild to severe VL atrophy, while only 11.1 % of patients in the control group presented this feature (P < 0.001).

CONCLUSIONS

The medial parapatellar incision for TKA surgical access does not generate definitive morphological changes in the VM and VL muscle fibers but may contribute to VL atrophy.

The smallest worthwhile effect is superior to the MCID for estimating acceptable benefits of knee arthroplasty

BACKGROUND AND OBJECTIVES

Traditionally, the minimal clinically important difference (MCID) is used to judge the meaningfulness of outcomes in total knee arthroplasty (TKA). However, MCID estimates do not consider patient costs, potential side effects, and inconveniences. MCIDs vary substantially across TKA studies and have several conceptual and psychometric problems. A more scientifically sound alternative for estimating benefits patients expect TKA is the smallest worthwhile effect (SWE), measured with the benefit-harm trade-off method.

METHODS

We recruited 121 participants and followed them for 6 months after surgery. All participants completed Knee Injury and Osteoarthritis Score (KOOS) Pain and Function, and underwent an interview using the benefit-harm trade-off method.

RESULTS

The absolute SWE at the 50th percentile (approximating the average patient) was 31 points KOOS Pain improvement and 28 points for KOOS Function, daily living. Construct validity was supported with strong associations between meeting SWE (yes or no) and satisfaction with 6-month outcome (yes or no) using Pearson Chi Square (24.5, P < 0.001).

CONCLUSION

Current MCID-based methods for interpreting KOOS change scores have flaws while the SWE method is conceptually superior. We determined the SWE of TKA that would justify the costs, risks, and inconveniences of surgery. SWE estimates suggest that patients expect a substantially greater change in KOOS scores than would be expected using MCID estimates. Clinicians can use SWE estimates when discussing likely outcomes and potential TKA benefits and risks with their patients.

Construction of an Administrative Osteoarthritis Severity Index

OBJECTIVE

Electronic health record (EHR) databases are a powerful resource to investigate clinical trajectories of osteoarthritis (OA). There are no existing EHR tools to evaluate risk for knee arthroplasty (KA). We developed an OA severity index (OASI) using EHR data and demonstrate the index's association with time to KA.

METHODS

This retrospective cohort study used 2010-2018 nationally distributed Optum EHR data. Eligible patients were 45 to 80 years old with a new diagnosis of knee OA in 2011-2012 and no prior KA. The OASI was a sum of first instance of x-ray imaging, advanced imaging, intra-articular injection, nonsteroidal anti-inflammatory drugs, and opioids. Principal components analysis index (PCI) score was also explored. Extended Cox proportional hazard models assessed time-dependent OASI and time to KA.

RESULTS

Among 16,675 eligible patients, 12.7% underwent KA. Median follow-up time was 72 months. Adjusted OASI models showed each additional event almost doubled the risk for KA (adjusted hazard ratio = 1.80, 95% confidence interval: 1.75-1.86). Similar results were observed for PCI.

CONCLUSION

The sum OASI performs well identifying patients who would undergo KA and offers simplicity versus the PCI. Although replication in other cohorts is recommended, the OASI appears to be a novel and valid means to measure clinical OA severity in research studies using large EHR-based cohorts.

Exploring the Impact and Acceptance of Wearable Sensor Technology for Pre- and Postoperative Rehabilitation in Knee Replacement Patients: A U.K.-Based Pilot Study

Knee replacement operations are common, highly successful procedures that are increasing in frequency. The COVID-19 pandemic has emphasized the need for innovative care pathways that reduce face-to-face appointments. We report on the impact of introducing a wearable sensor for pre- and postoperative rehabilitation of 21 knee replacement patients at 2 hospitals in the U.K.

Defining Failure in Primary Total Joint Arthroplasty: The Minimal Clinically Important Difference for Worsening Score

BACKGROUND

We define the value of the Minimal Clinically Important Difference for Worsening (MCID-W) for Patient-Reported Outcomes Measurement Information System Physical Function short form 10-a (PROMIS-PF-10a) score for primary total joint arthroplasty (TJA) of the hip and knee and describe the risk factors for patients scoring worse than the MCID-W.

METHODS

This retrospective study was performed using 3414 primary TJA patients. PROMIS-PF-10a scores were collected at the preoperatively and postoperatively, and patients were classified based on reaching Minimal Clinically Importance Difference for Improvement (MCID-I), MCID-W, or "no significant change" after TJA (scores betweex`n MCID-W and MCID-I). MCID-W and MCID-I values were determined by a distribution method. The association between numerous variables and scoring worse than the MCID-W of PROMIS-PF-10a was then evaluated through multiple logistic regression. A threshold for preoperative PROMIS-PF-10a score predicting decline past MCID-W was determined using the Youden index and receiver operating characteristic curve.

RESULTS

The MCID-W for TJA was -1.89. Notably, increasing length of stay (odds ratio [OR] 1.073, 95% confidence interval [CI] 1.029-1.119, P < .001) and increasing preoperative PROMIS-PF-10a scores (OR 1.117, 95% CI 1.091-1.144, P < .001) were associated with increased likelihood of decline past the MCID-W of the PROMIS-PF-10a for TJA compared with patients who achieved the MCID-I. A community hospital with a dedicated joint replacement center was associated with a decreased risk for decline past the MCID-W (OR 0.601, 95% CI 0.402-0.899; P = .013).

CONCLUSION

We described the MCID-W value (-1.89) for the PROMIS-PF-10a questionnaire for knee and hip TJA and associated patient- and hospital-level risk factors for failure after TJA. Healthcare funding initiatives should be directed toward modifiable factors associated with clinically significant worse outcomes after TJA.

Total Knee Arthroplasty Assessments Should Include Strength and Performance-Based Functional Tests to Complement Range-of-Motion and Patient-Reported Outcome Measures

Range of motion (ROM) and pain often define successful recovery after total knee arthroplasty (TKA), but these routine clinical outcomes correlate poorly or not at all to functional capacity after TKA. The purpose of this Perspective is to underscore the importance of muscle strength and performance-based functional tests in addition to knee ROM and patient-reported outcome (PRO) measures to evaluate outcomes after TKA. Specifically: (1) muscle strength is the rate-limiting step for recovery of function after TKA; (2) progressive rehabilitation targeting early quadriceps muscle strengthening improves outcomes and does not compromise ROM after TKA; (3) ROM and PROs fail to fully capture functional limitations after TKA; and (4) performance-based functional tests are critical to evaluate function objectively after TKA. This Perspective also addresses studies that question the need for or benefit of physical therapy after TKA because their conclusions focus only on ROM and PRO measures. Future research is needed to determine the optimal timing, delivery, intensity, and content of physical therapy.

The Impact of Total Joint Arthroplasty on Long-Term Physical Activity: A Secondary Analysis of the Health and Retirement Study

OBJECTIVE

Physical inactivity is the fourth-leading cause of global mortality and is prevalent among people with lower extremity osteoarthritis. Lower extremity osteoarthritis is the most common arthritis type afflicting older adults, and total joint arthroplasty (TJA) performed to address the condition is Medicare's largest annual expense. Despite TJA intervention to address the disabling effects of osteoarthritis, physical activity (PA) level remains stable 6 months after TJA; however, the effect of TJA on long-term PA $(\ge$2 y) in a representative sample of older adults is unknown. The purpose of this study was to test the hypothesis that PA would remain stable in the long term.

METHODS

In this longitudinal observational study, a probability-weighted difference-in-differences analysis was conducted to observe the predictive margins of nontraumatic hip or knee TJA on levels of vigorous and moderate PA after 2 years. A combined Health and Retirement Study data set of community-dwelling adults who were >55 years old, had symptomatic osteoarthritis, and were in need of TJA between 2008 and 2018 (N = 4652) was used.

RESULTS

TJA was not associated with vigorous PA ($\delta$ = 2.37; SE = 5.23) or moderate PA ($\delta$ = -2.84; SE = 7.76) after 2 years.

CONCLUSION

TJA was not associated with increased long-term PA in older adults with osteoarthritis.

IMPACT

Physical therapists should not assume that there will be a natural increase in PA after functional recovery from TJA procedures. Older adults with lower extremity osteoarthritis may benefit from PA screening and promotion practices in physical therapy services.

LAY SUMMARY

Receiving a total joint replacement does not lead to increased physical activity levels 2 years after surgery.

Effect of continuous passive motion on the early recovery outcomes after total knee arthroplasty

Introduction

Continuous passive motion (CPM) is a frequently used method in the early post-operative rehabilitation of patients after knee surgery. In this study, the effectiveness of the CPM method was evaluated after primary total knee arthroplasty during an early recovery period.

Methods

Eighty patients undergoing total knee arthroplasty were assigned into two groups. The experimental group received CPM and active exercises, while the control group active exercises only. All subjects were evaluated once before the surgery and at a discharge, in terms of mean active range of motion (AROM), mean Knee Society Score (KSS), and Western Ontario and MacMaster Universities Osteoarthritis Index (WOMAC).

Results

The mean AROM for the experimental group was 82.3° ± 14.3° and 76.1° ± 22.2° for the control. The mean KSS score was 136.4 ± 19.3 points for the experimental group, and 135.7 ± 15.1 for the control. There were no statistical differences between the two groups. The KSS functional score was 66.4 ± 8.1 points for the experimental group compared to 62.2 ± 7.3 points for the control, but there was a statistically significant difference between the groups at discharge from the hospital (p = 0.009). A subjective estimation of the pain level, joint stiffness and function also showed a statistically significant difference between the two groups (38.6 ± 14.3 points for the CPM group and 21.2 ± 15.7 for the control).

Conclusion

These findings show that there is no significant effect of CPM in terms of improving clinical measurements. However, there was a significant beneficial effect on the subjective assessment of pain level, joint stiffness, and functional ability.

Total knee arthroplasty patients using the in-home X10 machine fully recovered. No additional therapy required

Following total knee arthroplasties patients using the X10 increased their quadriceps strength 120% at 30 days post-surgery compared to their pre-surgical baseline. This contrasts sharply with contrast studies outpatient physical therapy that show patients suffer a 50-60% quadriceps strength deficit at 30 days post-surgery. For X10 patients, the average range of motion at 30 days was 124° and at discharge it was 128° (mean 43 days). The trial involved a single surgeon and two groups. Group one (21 patients) used only the X10 for pre-habilitation and rehabilitation, while group two (20 patients) used X10 alone for pre-habilitation and then utilized the X10 plus home care plus outpatient physical therapy for rehabilitation. Adding home care and outpatient physical therapy did not improve outcomes compared to patients who utilized X10 alone. Our results show no significant difference between the two groups. Indicating that the X10 by itself is adequate to completely rehabilitation patients from total knee arthroplasties. Finally, we compared our results to those of Calatayud et al.¹ who monitored two groups of patients, one group had only physical therapy for rehabilitation while the other group used physical therapy for both prehabilitation and rehabilitation. Our results were superior to Calatayud et al.¹ for extension, flexion, and quadriceps strength; for each of these measures the X10 treatment groups improved over time, while the Calatayud et al.¹ groups showed losses.

Food sources of dietary fibre and risk of total knee replacement related to severe osteoarthritis, the Singapore Chinese Health Study

Objectives

We aimed to evaluate the association between fibre intake and its food sources, and the risk of total knee replacement (TKR) due to severe knee osteoarthritis (KOA).

Methods

We used data from the Singapore Chinese Health Study, a prospective cohort study that recruited 63 257 participants aged 45–74 years from 1993 to 1998. At baseline, we assessed diet using a validated 165-item semiquantitative food frequency questionnaire, together with body mass index (BMI) and lifestyle factors. Incident TKR cases were identified via record linkage with nationwide hospital discharge database through 2017.

Results

There were 2816 cases of incident TKR due to severe KOA. The total fibre intake at baseline was not associated with the risk of TKR after adjustment for confounders. Among the food sources of fibre, higher intake of legumes was associated with a lower risk of TKR in a dose-dependent manner; compared with those having the lowest quartile intake, HR (95% CI) was 0.86 (0.76, 0.96) for those having the highest quartile intake (p for trend=0.004). This association was consistent after including BMI in the model and homogeneous across BMI categories. The consumption of other fibre sources, namely grain products, nuts and seeds, soy food, fruits and vegetables, was not associated with the risk of TKR.

Conclusion

Intake of legumes, but not total fibre, was associated with a reduced risk of TKR. Further research is needed to replicate our findings and to evaluate possible biological mechanisms that could explain the effect of dietary legumes on pathogenesis or progression of KOA.

Social Determinants of Health and Patient-Reported Outcomes Following Total Hip and Knee Arthroplasty in Veterans

BACKGROUND

Social determinants of health (SDOH) are the conditions in which people are born, grow, live, work, and age. They are associated with disparities in outcomes following total joint arthroplasty (TJA). These disparities occur even in equal-access healthcare systems such as the Veterans Health Administration (VHA). Our goal was to determine whether SDOH affect patient-reported outcome measures (PROMs) following TJA in VHA patients.

METHODS

Patients scheduled to undergo total hip or knee arthroplasty at VHA Hospitals in Minneapolis, MN, Palo Alto, CA, and San Francisco, CA, prospectively completed PROMs before and 1 year after surgery. PROMs included the Hip disability and Osteoarthritis Outcome Score, the Knee injury and Osteoarthritis Outcome Score, and their Joint Replacement subscores. SDOH included race, ethnicity, marital status, education, and employment status. The level of poverty in each patient's neighborhood was determined. Medical comorbidities were recorded. Univariate and multivariate analyses were performed to determine whether SDOH were significantly associated with PROM improvement after surgery.

RESULTS

On multivariate analysis, black race was significantly negatively correlated with knee PROM improvement and Hispanic ethnicity was significantly negatively correlated with hip PROM improvement compared to whites. Higher baseline PROM scores and lower age were significantly associated with lower PROM improvement. Significant associations were also found based on education, gender, comorbidities, and neighborhood poverty.

CONCLUSION

Minority VHA patients have lower improvement in PROM scores after TJA than white patients. Further research is required to identify the reasons for these disparities and to design interventions to reduce them.

Risk scoring for time to end-stage knee osteoarthritis: data from the Osteoarthritis Initiative

OBJECTIVE

This study constructs a risk score for patients' progression to end-stage knee osteoarthritis (OA) within 4 years.

DESIGN

The Osteoarthritis Initiative (OAI) was a longitudinal study of the onset and progression of knee OA. Using a recent definition of end-stage knee OA, we implement interval-censored survival forests to select predictors of this endpoint. We fit an interval-censored Cox model for time to end-stage knee OA, using the selected predictors. The risk score is the Cox model's fitted linear combination of the nine selected baseline structural and symptomatic knee OA variables.

RESULTS

We fit our models on a training set of 2,701 patients, and we evaluate on an independent test set of 1,436 patients. On the test sample, we observe a concordance index of 0.86 between risk score and time to end-stage, AUC of 0.87 for predicting end-stage within 24, 36, and 48 months, and positive predictive values that increase with the risk score. This risk stratification algorithm could enrich clinical trial patient enrollment. By enrolling test sample patients with scores above a threshold, a trial could have included 91% of test set patients who reach end-stage within 4 years while only enrolling 45% of the test sample.

CONCLUSION

Using statistical methods, we construct and validate an interpretable risk score for time to end-stage knee OA. This score can help disease-modifying OA treatment developers to select candidates with the highest risk of fast-progressing knee OA.

Quality of life outcomes in patients undergoing knee replacement surgery: longitudinal findings from the QPro-Gin study

Background

Many patients report postoperative pain, limited improvement in physical function and poor quality of life (QOL) after knee replacement surgery. Our study uses baseline predictors of change to investigate the QOL of patients with knee osteoarthritis 3-months after knee replacement surgery.

Methods

A prospective observational study was designed to evaluate patients (n = 132) scheduled for uni-compartmental or total knee replacement surgery who were assessed at baseline (preoperatively) and 3-months after. Physical and mental endpoints based on the component scores of the SF-12 and on the Western Ontario and McMaster Universities Arthritis (WOMAC) index were used to investigate patients’ QOL. Generalised estimating equation methodology was used to assess patients’ baseline characteristics (age, sex, education, body mass index (BMI), comorbidity, depressive symptoms, cognitive impairment, smoking/alcohol and type of surgery), the study endpoints and their changes over a 3-month post-surgery period. Stratified analyses by rehabilitation status after discharge were performed.

Results

Longitudinal data analysis showed that the baseline factors associated with improvement in general QOL at the 3-month post-surgery assessment were higher BMI, a high comorbidity, total (as opposed to unicompartmental) knee replacement and low education level. Data analysis of the patients who underwent rehabilitation after discharge revealed that the current smokers’ physical QOL worsened over time. The general QOL was unchanged over time in the presence of depressive symptomatology.

Conclusions

These findings underline the importance of using comprehensive assessment methods to identify factors affecting functionality and QOL, and developing interventions to improve the health/wellbeing of patients after knee replacement.

Periarticular injection of tranexamic acid promotes early recovery of the range of knee motion after total knee arthroplasty

PURPOSE

Tranexamic acid (TXA) is a commonly used compound that reduces postoperative blood loss. Periarticular injection of TXA is a recently reported procedure with some advantages such as cost-effectiveness and the ease of performance over an intravenous or topical administration. However, its association with functional recovery remains unclear. This study aimed to examine the effect of periarticular injection of TXA on early postoperative recovery of knee functionality after total knee arthroplasty (TKA).

METHODS

Eighty-four patients who underwent primary unilateral TKA from February 2013 to August 2016 were classified into two groups based on whether they received TXA injection (44 cases each in the TXA and control groups). Patients in the TXA group received periarticular injection of TXA (1000 mg) just prior to incision closure. Ten-meter walk test (s), pain visual analog scale, knee extension muscle force (N), range of motion (ROM) (maximum flexion angle, maximum extension angle, and motion arc), and blood loss (mL) were assessed.

RESULTS

The maximum flexion angle and maximal extension angle on postoperative day (POD) 4, POD7, POD10, and POD14 in the TXA group were significantly larger than those in the control group. The postoperative drained blood in the TXA group was significantly less than that of the control group (543.9 ± 464.3 mL and 814.9 ± 481.4 mL, respectively, p < 0.05). No significant difference was observed in the other parameters at any time point.

CONCLUSION

Periarticular injection of TXA significantly promotes early recovery of knee ROM after TKA. Level of Evidence: Level IV, therapeutic case series.

Patients with metabolic syndrome have a greater rate of complications after arthroplasty: A systematic review and meta-analysis

Aims

Patients with metabolic syndrome (MetS) are known to be at increased risk of postoperative complications, but it is unclear whether MetS is also associated with complications after total hip arthroplasty (THA) or total knee arthroplasty (TKA). Here, we perform a systematic review and meta-analysis linking MetS to postoperative complications in THA and TKA.

Methods

The PubMed, OVID, and ScienceDirect databases were comprehensively searched and studies were selected and analyzed according to the guidelines of the Meta-analysis of Observational Studies in Epidemiology (MOOSE). We assessed the methodological quality of each study using the Newcastle-Ottawa Scale (NOS), and we evaluated the quality of evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE). Data were extracted and meta-analyzed or qualitatively synthesized for several outcomes.

Results

Ten cohort studies involving 1,352,685 patients were included. Qualitative analysis suggested that MetS was associated with a higher incidence of cardiovascular events, and meta-analysis showed that MetS increased the risk of all-cause complications (risk ratio (RR) 1.55, 95% confidence interval (CI) 1.28 to 1.89), surgical site infection (SSI; RR 2.99, 95% CI 1.30 to 6.90), urinary tract infection (UTI; RR 2.58, 95% CI 1.03 to 6.43), and 30-day readmission (RR 1.45, 95% CI 1.33 to 1.59). There was insufficient evidence for assessing an association between MetS and venous thromboembolism events, pulmonary or gastrointestinal complications, or mortality.

Conclusion

Patients with MetS undergoing THA and TKA are at increased risk of all-cause complications, cardiovascular complications, SSI, UTI, and 30-day readmission. Surgeons should be aware of the increased risk of these complications in MetS, and presurgical protocols for these complications should give special consideration to MetS patients.

Cite this article:Bone Joint Res. 2020;9(3):120–129.

A greater reduction in the distal femoral anterior condyle improves flexion after total knee arthroplasty in patients with osteoarthritis

BACKGROUND

The effect of an anterior condylar height (ACH) change after total knee arthroplasty (TKA) is not well-known. The effect of an ACH change was evaluated on postoperative knee flexion, New Knee Society Scores (2011KSS), and patellofemoral contact force.

METHODS

The study included 101 knees that underwent TKA. The medial or lateral ACH was measured using pre-operative and postoperative computed tomography. Pearson correlation between the change in ACH and knee flexion was calculated. The determinant of the change in flexion was evaluated using multivariable linear regression. The association between ACH and 2011KSS was assessed. Using the cases with the three highest and three lowest pre-operative medial ACHs, computer simulation was performed to detect the changes in patellofemoral contact forces.

RESULTS

A postoperative reduction in ACH correlated with increased flexion at one year (medial ACH, R = 0.58; lateral ACH, R = 0.48). On multivariable linear regression, reductions in medial ACH (β = 1.7, P < 0.001) and pre-operative flexion (β = -0.3, P < 0.001) were associated with increased flexion. A decrease in ACH was associated with improvements in advanced activities (medial, R² = 0.06; lateral, R² = 0.08) in 2011KSS. On computer simulation, all three cases with reduced and increased medial ACHs showed decreased and increased patellofemoral contact forces, respectively.

CONCLUSIONS

A change in ACH was an independent predictor of knee flexion after TKA. Greater reduction in ACH was associated with improved flexion after TKA, whereas an increase in postoperative ACH may be a risk factor for flexion loss.

Use of Recommended Non-surgical Knee Osteoarthritis Management in Patients prior to Total Knee Arthroplasty: A Cross-sectional Study

OBJECTIVE

Our aim was to assess prior use of core recommended non-surgical treatment among patients with knee osteoarthritis (OA) scheduled for total knee arthroplasty (TKA), and to assess potential patient-level correlates of underuse, if found.

METHODS

This was a cross-sectional study of patients undergoing TKA for primary knee OA at 2 provincial central intake hip and knee clinics in Alberta, Canada. Standardized questionnaires assessed sociodemographic characteristics, social support, coexisting medical conditions, OA symptoms and coping, and previous non-surgical management. Multivariable logistic regression was used to assess the patient-level variables independently associated with receipt of recommended non-surgical knee OA treatment, defined as prior use of pharmacotherapy for pain, rehabilitation strategies (exercise or physiotherapy), and weight loss if overweight or obese (body mass index ≥ 25 kg/m²).

RESULTS

There were 1273 patients included: mean age 66.9 years (SD 8.7), 39.9% male, and 44.1% had less than post-secondary education. Recommended non-surgical knee OA treatment had been used by 59.7% of patients. In multivariable modeling, the odds of having received recommended non-surgical knee OA treatment were significantly and independently lower among individuals who were older (OR 0.97, 95% CI 0.95-0.99), male (OR 0.33, 0.25-0.45), and who lacked post-secondary education (OR 0.70, 0.53-0.93).

CONCLUSION

In a large cross-sectional analysis of knee OA patients scheduled for TKA, 40% of individuals reported having not received core recommended non-surgical treatments. Older individuals, men, and those with less education had lower odds of having used recommended non-surgical OA treatments.

Collagen microsphere based 3D culture system for human osteoarthritis chondrocytes (hOACs)

The current study aims to evaluate collagen microencapsulation as an in vitro 3D culture platform for human osteoarthritic chondrocytes (hOACs), and to exemplify its feasibility in screening potential disease modifying factors. We first isolated and expanded hOACs from osteoarthritis (OA) cartilage samples harvested from multiple patients during total knee replacement (TKR) surgery. These cells were microencapsulated into collagen microspheres for subsequent 3D cultures. The change in chondrocyte phenotypes and OA phenotype was evaluated over time, using 2D monolayer culture and traditional 3D pellet culture as controls. The hOACs in the 3D collagen microsphere model resumed their in vivo phenotypes when compared to 2D monolayer. When compared with the 3D pellet model, the 3D hOAC-collagen microsphere model better recapitulated the OA phenotypes. We further demonstrated the responsiveness of the microencapsulated hOACs towards a number of external factors altering the chondrogenic phenotype, corroborating with previous studies. The hOAC encapsulated collagen microspheres better maintained the hOAC phenotype than the traditional 2D monolayer and 3D pellet cultures. The feasibility to use this hOAC-collagen microsphere in vitro model as a screening platform for disease-modifying agents has been demonstrated, contributing to future development of OA therapeutics.

The Impact of Frailty on Short-Term Outcomes After Elective Hip and Knee Arthroplasty in Older Adults: A Systematic Review

Introduction

This systematic literature review evaluates (1) frailty in older adults as a risk factor for short-term adverse events and suboptimal clinical outcomes after total joint arthroplasty and (2) interventions to improve arthroplasty outcomes in these frail patients.

Methods

PubMed, EMBASE, Cochrane Register of Controlled Trials, SCOPUS, AgeLine, and Web of Science were searched from database inception to November 22, 2017; gray literature and references were also searched. Studies including adults ≥65 years of age undergoing hip or knee arthroplasty and measuring preoperative frailty and postoperative adverse events or clinical outcomes within 90 days of surgery were included. Two investigators independently screened all abstracts and extracted data; disagreements were adjudicated by a third reviewer. Risk of bias was assessed using the Newcastle-Ottawa scale for cohort studies and the Cochrane Risk of Bias tool for randomized controlled trials. Study quality was assessed using a 5-point scale modified from the Oxford Centre for Evidence-Based Medicine tool.

Results

Of 1913 abstracts identified, 82 full texts were reviewed, and 13 met inclusion criteria: 5 prospective cohort studies, 6 retrospective cohort studies, and 2 randomized controlled trials covering 382 763 total patients. These studies used 13 frailty instruments and assessed 32 distinct outcomes. Substantial heterogeneity precluded valid meta-analysis; results were qualitatively summarized by study design, frailty instrument, and outcome type. Of the 11 cohort studies, 10 found significant associations between frailty and poor postoperative outcomes. Trials of preoperative frailty-modifying interventions found no association between interventions and improved outcomes.

Discussion

Standardizing frailty measurement would improve generalizability, permitting the assessment of associations with patient-reported and functional outcome measures, as well as the efficacy of interventions to improve outcomes, in frail patients undergoing arthroplasty.

Conclusions

Frailty is associated with higher rates of short-term adverse events and worse clinical outcomes after elective hip and knee arthroplasty.

Outcomes of Primary Total Knee Arthroplasty in Patients With Parkinson's Disease

BACKGROUND

Parkinson's disease is a degenerative disorder causing rigidity, bradykinesia, and tremor of the motor system. There is significant paucity of evidence regarding whether total knee arthroplasty (TKA) is of benefit in patients with both Parkinson's disease and osteoarthritis. We aimed to compare outcomes and complications of TKA between patients with Parkinson's disease and those without.

METHODS

A cohort of 43 knees from 35 patients with Parkinson's disease who received a primary TKA between January 2004 and December 2015 were retrospectively extracted from a private clinical database held by 2 surgeons and compared to an age and gender-matched control group of 50 knees from 41 patients. TKAs were performed by 2 surgeons at 1 tertiary private hospital.The indication for TKA in both groups was osteoarthritis. Difference between preoperative and 1-year range of movement (ROM) and 12-point Oxford Knee Score (OKS) was assessed using Student's unpaired t-test. Postoperative complications and revision procedures were also recorded during the follow-up period. The minimal clinically important difference for OKS at 1-year follow-up, defined as improvement of ≥6, was also assessed.

RESULTS

In the Parkinson's group, mean ROM improvement was 14° (100° preoperatively to 114° at 12 months), compared to 12° in the control group (102°-114°, respectively). Mean OKS improvement was 15 in the Parkinson's group (23 preoperatively to 38 at 12 months) compared to 17 in the control group (23 and 40, respectively.) No significant difference was identified between the 2 groups for either ROM (P = .96) or OKS (P = .45.) All Parkinson's patients achieved the minimal clinically important difference at 1-year follow-up. There were no mortalities during the study follow-up period and no significant difference in complication rates between the 2 groups (P = .41).

CONCLUSION

Parkinson's disease was not associated with poorer functional outcomes or increased complications compared to controls in our study. We suggest that Parkinson's disease is not an absolute contraindication to TKA.

Interactive Surgery System with 3D Electromagnetic Motion Tracker for Training Surgeons in Skin Cutting Skills Needed in Total Knee Arthroplasty

Total knee arthroplasty (TKA) is an effective surgery for knees damaged by osteoarthritis, rheumatoid arthritis, and post-traumatic arthritis. This procedure requires an expert surgeon with a high level of skill and experience. Although a navigation system for improving precision and shortening operative time has been already studied, there has not yet been a study done on an instruction system for improving the skills of surgeons. The purpose of this study is to develop a training system that teaches the TKA surgery so that non-expert surgeons can use it to obtain skin-cutting skills. The proposed method includes a simulator for a model knee with a 3D electromagnetism motion tracker. Through experimentation, a method of evaluating incisions into the skin is established by tracing a line with a mock scalpel. The proposed method is applied to six non-experts. The results for the length experiments are 87.82±8.88 (Set 1: non-teaching), 92.66±5.77 (Set 2: teaching), and 92.14±6.17 (Set 3: non-teaching). The results for the position experiments are 70.64±15.11 (Set 1: non-teaching), 83.63±10.07 (Set 2: teaching), and 82.05±7.80 (Set 3: non-teaching). In conclusion, the proposed method succeeds in teaching the operator scalpel incision skills.

Hyaluronic Acid Injections for Treatment of Advanced Osteoarthritis of the Knee: Utilization and Cost in a National Population Sample

BACKGROUND

The prevalence of knee osteoarthritis is increasing in the aging U.S.

POPULATION

The efficacy and cost-effectiveness of the use of hyaluronic acid (HA) injections for the treatment of knee osteoarthritis are debated. In this study, we assessed the utilization and costs of HA injections in the 12 months preceding total knee arthroplasty (TKA) and evaluated the usage of HA injections in end-stage knee osteoarthritis management in relation to other treatments.

METHODS

MarketScan Commercial Claims and Encounters and Medicare Supplemental and Coordination of Benefits databases (Truven Health Analytics) were reviewed to identify patients who underwent TKA from 2005 to 2012. The utilization of patient-specific osteoarthritis-related health care (including medications, corticosteroid injections, HA injections, imaging, and office visits) and payment information were analyzed for the 12 months preceding TKA.

RESULTS

A total of 244,059 patients met the inclusion criteria. Of those, 35,935 (14.7%) had ≥1 HA injection in the 12 months preceding TKA. HA injections were responsible for 16.4% of all knee osteoarthritis-related payments, trailing only imaging studies (18.2%), and HA injections accounted for 25.2% of treatment-specific payments, a rate that was higher than that of any other treatment. Patients receiving HA injections were significantly more likely to receive additional knee osteoarthritis-related treatments compared with patients who did not receive HA injections.

CONCLUSIONS

Despite numerous studies questioning the efficacy and cost-effectiveness of HA injections for osteoarthritis of the knee, HA injections are still utilized for a substantial percentage of patients. Given the paucity of data supporting the effectiveness of HA injections and the current cost-conscious health-care climate, decreasing their use among patients with end-stage knee osteoarthritis may represent a substantial cost reduction that likely does not adversely impact the quality of care.

Gonyautoxins: First evidence in pain management in total knee arthroplasty

Improvements in pain management techniques in the last decade have had a major impact on the practice of total knee arthroplasty (TKA). Gonyautoxin are phycotoxins, whose molecular mechanism of action is a reversible block of the voltage-gated sodium channels at the axonal level, impeding nerve impulse propagation. This study was designed to evaluate the clinical efficacy of Gonyautoxin infiltration, as a long acting pain blocker in TKA. Fifteen patients received a total dose of 40 μg of Gonyautoxin during the TKA operation. Postoperatively, all patients were given a standard painkiller protocol: 100 mg of intravenous ketoprofen and 1000 mg of oral acetaminophen every 8 hours for 3 days. The Visual Analog Scale (VAS) pain score and range of motion were recorded 12, 36, and 60 hours post-surgery. All patients reported pain of 2 or less on the VAS 12 and 36 hours post-surgery. Moreover, all scored were less than 4 at 60 hours post-surgery. All patients achieved full knee extension at all times. No side effects or adverse reactions to Gonyautoxin were detected in the follow-up period. The median hospital stay was 3 days. For the first time, this study has shown the effect of blocking the neuronal transmission of pain by locally infiltrating Gonyautoxin during TKA. All patients successfully responded to the pain control. The Gonyautoxin infiltration was safe and effective, and patients experienced pain relief without the use of opioids.

Age and Preoperative Knee Society Score Are Significant Predictors of Outcomes Among Asians Following Total Knee Arthroplasty

BACKGROUND

The ability to predict patients' functional outcomes will add value to preoperative counseling. The purpose of this study was to evaluate predictors of good outcomes following total knee arthroplasty (TKA) among Asian patients.

METHODS

Registry data from 2006 to 2010 were extracted. The Oxford Knee Score (OKS) and the Short Form (SF)-36 physical component summary (PCS) were used to evaluate outcomes. A "good outcome" was defined as an improvement in scores of greater than or equal to the minimal clinically important difference (MCID) in the primary analysis. The MCID for the OKS was 5, and the MCID for the PCS was 10. For the sensitivity analyses, a "good outcome" was defined as an OKS of <30 and a PCS score of >50. Clinical variables were used to develop a multiple logistic regression model for a good outcome following total knee arthroplasty at 5 years.

RESULTS

Follow-up data were available for 3,062 patients who underwent primary TKA (mean age of 66.4 years; 79.5% female). Eighty-five percent had a good outcome on the basis of the OKS and 83%, on the basis of the SF-36 PCS. Age and preoperative Knee Society score (KSS) were found to be significant predictors. When outcomes were assessed by the MCID, lesser age and lower (worse) preoperative KSS predicted a good outcome at 5 years. When outcomes were assessed by absolute criteria (postoperative scores measured against OKS and PCS thresholds), a higher (better) preoperative KSS predicted a good outcome at 5 years. Body mass index, preoperative flexion range, SF-36 mental component summary (MCS) score, mechanical alignment, sex, education level, ethnicity, operative side, number of comorbidities, type of anesthesia, and type of implant were found not to be significant predictors.

CONCLUSIONS

The majority of Asian patients with osteoarthritis had good outcomes according to the MCID criterion and benefitted from primary TKA. On the basis of our findings, we believe that older patients with a lower (worse) preoperative KSS can be informed that they have a high likelihood of improvement but a lower likelihood of achieving as good a functional outcome as those with better scores.

LEVEL OF EVIDENCE

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

Return to work after knee replacement: a qualitative study of patient experiences

OBJECTIVE

An increasing number of patients in the working population are undergoing total knee replacement (TKR) for end-stage osteoarthritis. The timing and success of return to work is becoming increasingly important for this group of patients with social and economic implications for patients, employers and society. There is limited understanding of the patient variables that determine the ability to return to work. Our objective was (from the patient's perspective) to gain an insight into the factors influencing return to work following knee replacement.

SETTING AND PARTICIPANTS

This qualitative study was undertaken in a secondary-care setting in a large teaching hospital in the north of England. Semistructured interviews were carried out with 10 patients regarding their experiences of returning to work following TKR.

OUTCOMES

Interviews were transcribed and analysed using a qualitative thematic approach to identify the factors influencing return to work from the patient's perspective.

RESULTS

Three themes were identified that influenced the process of return to work, from the patient's perspective. These were delays in surgical intervention, limited and often inconsistent advice from healthcare professionals regarding return to work, and finally the absence of rehabilitation to optimise patient's recovery and facilitate return to work.

CONCLUSIONS

There is currently no consistent process to optimise return to work for patients of working age after TKR. The impact of delayed surgical intervention, limited advice regarding return to work, and a lack of work-focused rehabilitation, all contribute to potential delays in successful return to work. There is a need to change the focus of healthcare provision for this cohort of patients, and provide a tailored healthcare intervention to optimise patient outcomes.

Quality-Adjusted Life Years Gained by Hip and Knee Replacement Surgery and Its Aftercare

OBJECTIVES

To determine the lifetime quality-adjusted life years (QALYs) gained by total joint arthroplasty (TJA), and assess the QALYs attributed to specific postoperative rehabilitation interventions.

DESIGN

Secondary analysis of 2 multicenter, randomized controlled trials (RCTs) with 3-, 6-, 12-, and 24-month follow-up.

SETTING

Two university hospitals, 2 municipal hospitals, and 1 rural hospital.

PARTICIPANTS

Patients (N=827) who underwent total hip arthroplasty (THA) or total knee arthroplasty (TKA).

INTERVENTIONS

RCT A: 465 patients were randomly assigned to receive aquatic therapy (pool exercises aimed at training of proprioception, coordination, and strengthening) 6 versus 14 days after THA or TKA.

RCT B

362 patients were randomly assigned to either perform or not perform ergometer cycling beginning 2 weeks after THA or TKA.

MAIN OUTCOME MEASURE

QALYs, based on the Short Form-6 Dimensions utility, measured at baseline and 3, 6, 12, and 24 months' follow-up.

RESULTS

After hip arthroplasty, the lifetime QALYs increased by 2.35 years in the nonergometer group, and by 2.30 years in the early aquatic therapy group. However, after knee arthroplasty, the lifetime QALYs increased by 1.81 years in the nonergometer group, and by 1.60 years in the early aquatic therapy group. By ergometer cycling, .55 additional QALYs could be gained after hip and .10 additional QALYs after knee arthroplasty, while the additional QALYs attributed to the timing of aquatic therapy were .12 years after hip and .01 years after knee arthroplasty.

CONCLUSIONS

This analysis provides a sound estimate for the determination of the lifetime QALYs gained by THA and TKA. In addition, this analysis demonstrates that specific postoperative rehabilitation can result in an additional mean QALY gain of .55 years, which represents one fourth of the effect of surgery. Even if this is interpreted as a small effect at an individual level, it is important when extrapolated to all patients undergoing TJA. At a national level, these improvements appear to have a similar magnitude of QALY gain when compared with published data regarding medications to lower blood pressure in all persons with arterial hypertension.

Investigational drugs for the treatment of osteoarthritis

INTRODUCTION

Osteoarthritis (OA) is a common joint disease with multiple pathophysiological processes, affecting the whole joint. Current therapeutic options such as NSAIDs can provide a palliative effect on symptoms but have limited effect on disease progression. New drugs targeting OA structures may retard disease progression at an earlier stage and delay the need for joint replacement.

AREAS COVERED

Some drugs have entered into clinical trials and a few, such as strontium ranelate, do have improvements in both pain and structure changes. However, most of them have failed in clinical trials largely due to increased side effects or the failure to identify the right OA phenotype for the right drug in clinical design. This review describes various investigational drugs developed for the treatment of OA covering those at stages from preclinical experiments to early phase clinical trials. They include drugs for slowing cartilage degradation, regulating cartilage metabolism, targeting subchondral bone, controlling inflammation and relieving pain.

EXPERT OPINION

Treatment options for OA remain limited. However, with the emergence of sensitive tools to detect early disease progression and identification of different OA phenotypes, disease-modifying anti-OA drugs with increased benefit and reduced risks will become available for OA treatment in the near future.

Does Pre-Operative Physiotherapy Improve Outcomes in Primary Total Knee Arthroplasty? - A Systematic Review

We undertook a systematic review of 11 randomised controlled trials comparing patient outcomes in total knee arthroplasty in those who had undergone pre-operative physiotherapy-based interventions against control groups. Results show that there is little evidence that pre-operative physiotherapy brings about significant improvements in patient outcome scores, lower limb strength, pain, range of movement and hospital length of stay following total knee arthroplasty. The overall quality of the studies was moderate to poor, mostly due to the small sample sizes.

Different femorotibial contact on the weight-bearing: midflexion between normal and varus aligned knees after total knee arthroplasty

PURPOSE

The influence of residual malalignment on biomechanical analysis after total knee arthroplasty (TKA) is currently uncertain. The hypothesis is that postoperative alignment would influence the in vivo kinematics after TKA, under weight-bearing conditions but not under non-weight-bearing condition. The purpose of the present study was to compare weight-bearing and non-weight-bearing conditions and to evaluate the effect of the postoperative alignment on the in vivo kinematics after posterior cruciate ligament-retaining TKA during midflexion using 2-dimensional/3-dimensional registration.

METHODS

Thirty knees of 30 patients with pre-operative varus deformity were divided into 2 groups according to their postoperative alignment: the normal alignment group (N = 21) and the varus alignment group (N = 9).

RESULTS

Under weight-bearing conditions, the varus alignment group showed a significant posterior displacement of the medial femoral condyle (flexion: 80°, 90° P < 0.05) and a significant anterior displacement of the lateral femoral condyle (flexion: 10° P < 0.01, 20° P < 0.05, and extension: 10°, 20° P < 0.01, 30°, 40° P < 0.05) as compared with the normal alignment group. In contrast, no significant difference in the medial and lateral femoral condyle positions under non-weight-bearing conditions was observed between the normal and varus alignment groups.

CONCLUSION

The postoperative alignment influenced knee kinematics under weight-bearing conditions. The weight load influenced knee kinematics through posterior tibial slope and induced greater lateral femoral condyle mobility, which might explain the better clinical and functional outcome. These findings contribute to gaining a proper understanding of the in vivo kinematics of the postoperative varus alignment and might be useful for orthopaedic surgeons in the achievement of patient satisfaction.

LEVEL OF EVIDENCE

III.

Assessing changes in subjective and objective function from pre- to post-knee arthroplasty using the Cardiff Dempster-Shafer theory classifier

The purpose of this study is to assess changes in subjective and objective function from pre- to post-knee arthroplasty (KA) using a combined classifier technique. Twenty healthy adults (50-80 years) and 31 KA patients (39-81 years) were studied (4 weeks pre- and 6 months post-KA). Questionnaire measures of subjective pain, joint stability, activity and function were collected. Objective functional assessment included goniometry, ultrasound imaging and 3-D motion analysis/inverse modelling of gait and sit-stand. An optimal set of variables were used to classify function using the Cardiff Dempster-Shafer theory (DST) method. Out of sample accuracy of the classifiers ranged between 90% and 94% for segregating healthy individuals and pre-KA patients. Post-KA subjective function improved with 74% classified as healthy. However, there was minimal improvement in objective measures (23% classified as healthy). The novel use of Cardiff DST segregated KA patients from healthy individuals and estimated changes in function from pre- to post-surgery. KA patients had improved pain and function post-operation but objective knee joint measures remained different to healthy individuals.

Implant positioning in TKA: comparison between conventional and patient-specific instrumentation

The number of total knee arthroplasty (TKA) procedures continuously increases, with good to excellent results. In the last few years, new surgical techniques have been developed to improve prosthesis positioning. In this context, patient-specific instrumentation is included. The goal of this study was to compare the perioperative parameters and the spatial positioning of prosthetic components in TKA procedures performed with patient-specific instrumentation vs traditional TKA. In this prospective comparative randomized study, 15 patients underwent TKA with 3-dimensional magnetic resonance imaging (MRI) preoperative planning (patient-specific instrumentation group) and 15 patients underwent traditional TKA (non-patient-specific instrumentation group). All patients underwent postoperative computed tomography (CT) examination. In the patient-specific instrumentation group, preoperative data planning regarding femoral and tibial bone resection was correlated with intraoperative measurements. Surgical time, length of hospitalization, and intraoperative and postoperative bleeding were compared between the 2 groups. Positioning of implants on postoperative CT was assessed for both groups. Data planned with 3-dimensional MRI regarding the depth of bone cuts showed good to excellent correlation with intraoperative measurements. The patient-specific instrumentation group showed better perioperative outcomes and good correlation between the spatial positioning of prosthetic components planned preoperatively and that seen on postoperative CT. Less variability was found in the patient-specific instrumentation group than in the non-patient-specific instrumentation group in spatial orientation of prosthetic components. Preoperative planning with 3-dimensional MRI in TKA has a better perioperative outcome compared with the traditional method. Use of patient-specific instrumentation can also improve the spatial positioning of both prosthetic components.

Intermediate and long-term quality of life after total knee replacement: a systematic review and meta-analysis

BACKGROUND

Total knee replacement is a highly successful and frequently performed operation. Technical outcomes of surgery are excellent, with favorable early postoperative health-related quality of life. This study reviews intermediate and long-term quality of life after surgery.

METHODS

A systematic review and meta-analysis of all studies published from January 2000 onward was performed to evaluate health-related quality of life after primary total knee replacement for osteoarthritis in patients with at least three years of follow-up. Key outcomes were postoperative quality of life, function, and satisfaction compared with the preoperative status. Strict inclusion and exclusion criteria were applied. Quality appraisal and data tabulation were performed with use of predefined criteria. Data were synthesized by narrative review and random-effects meta-analysis utilizing standardized mean differences. Heterogeneity was assessed with the tau(2) and I(2) statistics.

RESULTS

Nineteen studies were included in the review. Intermediate and long-term postoperative quality of life was superior to the preoperative level in qualitative and quantitative analyses. The pooled effect in combined WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) and KSS (Knee Society Score) outcomes was a marked improvement from baseline with respect to the total score (2.17; 95% CI [confidence interval], 1.13 to 3.22; p < 0.0001) and the pain (1.72; 95% CI, 0.97 to 2.46; p < 0.00001) and function (1.26; 95% CI, 0.87 to 1.64; p < 0.00001) domains. Most patients were satisfied with the surgery and derived substantial benefits for daily functional activities. Tau(2) (0.20 to 1.10) and I(2) (90% to 98%) values implied significant clinical and statistical heterogeneity.

CONCLUSIONS

Total knee replacement confers significant intermediate and long-term benefits with respect to both disease-specific and generic health-related quality of life, especially pain and function, leading to positive patient satisfaction. Recommendations for necessary future studies are provided.

LEVEL OF EVIDENCE

Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Preoperative pain and function profiles reflect consistent TKA patient selection among US surgeons

BACKGROUND

As the number of primary total knee arthroplasties (TKAs) performed in the United States increases, policymakers have questioned whether the indications and timing of TKA have evolved so that surgery is offered earlier.

QUESTIONS/PURPOSES

We analyzed data from a US national TKA cohort to evaluate variation in surgeon selection criteria for elective unilateral TKA based on preoperative patient-reported pain and function scores.

METHODS

Preoperative SF-36 (Physical Component Summary [PCS]/physical function) scores and Knee Injury and Osteoarthritis Outcome Score (KOOS) (pain, activities of daily living/function) of 4900 patients undergoing elective unilateral TKA enrolled in this national database of prospectively followed patients from 22 states were evaluated. The 25th, 50th, and 75th percentile pain and function scores for patients cared for in 24 orthopaedic offices with 20 or more patients in the database were compared to assess whether consistent preoperative criteria are used in selecting patients undergoing TKA across settings.

RESULTS

The preoperative global function (PCS median, 32.6; national norm, 50; SD, 10) and knee-specific function (KOOS median, 51.5; maximum score, 100; SD, 17) percentile scores represented substantial patient disability, because both values approached 2 SDs below ideal. Consistency in patients across 24 surgeon offices, and more than 100 surgeons, was noted because site-specific medians varied from the national median by less than the minimum clinically important change.

CONCLUSIONS

These data suggest that despite the rapidly growing use of TKA, surgeons in the participating sites use consistent patient criteria in scheduling TKA. Today's patients report significant pain and disability, supporting the need for TKA.

You'll know when you're ready: a qualitative study exploring how patients decide when the time is right for joint replacement surgery

Background

While some studies have identified patient readiness as a key component in their decision whether to have total joint replacement surgery (TJR), none have examined how patients determine their readiness for surgery. The study purpose was to explore the concept of patient readiness and describe the factors patients consider when assessing their readiness for TJR.

Methods

Nine focus groups (4 pre-surgery, 5 post-surgery) were held in four Canadian cities. Participants had been either referred to or seen by an orthopaedic surgeon for TJR or had undergone TJR. The method of analysis was qualitative thematic analysis.

Results

There were 65 participants, 66% female and 34% male, 80% urban, with an average age of 65 years (SD 10). Readiness reflected both the surgeon’s advice that the patient was clinically ready for surgery and the patient’s feeling that they were both mentally and physically ready for surgery. Mental readiness was described as an internal state or feeling of being ready or prepared while physical readiness was described as being physically fit and in good shape for surgery. Factors associated with readiness included: 1) pain: its severity, the ability to cope with it, and how it affected their quality of life; 2) mental preparation; 3) physical preparation; 4) the optimal timing of surgery, including age, anticipated rate of deterioration, prosthesis lifespan and the length of the waiting list.

Conclusions

Patient readiness should be assessed prior to TJR. By assessing patient readiness, health professionals can elucidate and deal with concerns and fears, understand and calibrate expectations, assess coping strategies, and use this information to help determine optimal timing, both before and after the surgical consultation.

Comparison of effects of supervised physiotherapy and a standardized home program on functional status in patients with total knee arthroplasty: a prospective study

[Purpose] The aim of this study was to determine the functional differences between total knee arthroplasty (TKA) patients who were treated with supervised physiotherapy or a standardized home program and perform a cost analysis. [Subjects and Methods] Patients who received total knee arthroplasty between January 2009 and June 2011 were enrolled in this study; those with mean ages of 64.25±3.86 (60-68) years (n=18) and 68.08±6.25 (61-79) years (n=16) were placed in the supervised physiotherapy and standardized home program groups, respectively. All patients were evaluated by the same researcher before and after surgery, and the therapy programs were applied by another physiotherapist. All patients were evaluated for joint range of motion (ROM), pain, functional status (WOMAC), overall quality of life (SF-36), and depressive symptoms (BECK Depression Scale). [Results] A significant clinical improvement was observed in postoperative assessments. A statistically significant difference could not be found between ROM and functional levels of the patients in both groups. [Conclusion] No difference was found between the patients performing supervised or standardized home program with respect to the effects on functional status. A home exercise program can be used in the rehabilitation of patients with TKA, and implementation of home exercise programs can also reduce health-care spending.

All-cause mortality and serious cardiovascular events in people with hip and knee osteoarthritis: a population based cohort study

BACKGROUND

Because individuals with osteoarthritis (OA) avoid physical activities that exacerbate symptoms, potentially increasing risk for cardiovascular disease (CVD) and death, we assessed the relationship between OA disability and these outcomes.

METHODS

In a population cohort aged 55+ years with at least moderately severe symptomatic hip and/or knee OA, OA disability (Western Ontario McMaster Universities (WOMAC) OA scores; Health Assessment Questionnaire (HAQ) walking score; use of walking aids) and other covariates were assessed by questionnaire. Survey data were linked to health administrative data to determine the relationship between baseline OA symptom severity to all-cause mortality and occurrence of a composite CVD outcome (acute myocardial infarction, coronary revascularization, heart failure, stroke or transient ischemic attack) over a median follow-up of 13.2 and 9.2 years, respectively.

RESULTS

Of 2156 participants, 1,236 (57.3%) died and 822 (38.1%) experienced a CVD outcome during follow-up. Higher (worse) baseline WOMAC function scores and walking disability were independently associated with a higher all-cause mortality (adjusted hazard ratio, aHR, per 10-point increase in WOMAC function score 1.04, 95% confidence interval, CI 1.01-1.07, p = 0.004; aHR per unit increase in HAQ walking score 1.30, 95% CI 1.22-1.39, p<0.001; and aHR for those using versus not using a walking aid 1.51, 95% CI 1.34-1.70, p<0.001). In survival analysis, censoring on death, risk of our composite CVD outcome was also significantly and independently associated with greater baseline walking disability ((aHR for use of a walking aid = 1.27, 95% CI 1.10-1.47, p = 0.001; aHR per unit increase in HAQ walking score = 1.17, 95% CI 1.08-1.27, p<0.001).

CONCLUSIONS

Among individuals with hip and/or knee OA, severity of OA disability was associated with a significant increase in all-cause mortality and serious CVD events after controlling for multiple confounders. Research is needed to elucidate modifiable mechanisms.

Effect of operating parameters on the removal of bone cement by a sawing process

The number of total knee arthroplasty revision surgeries is increasing each year, driven by the wide availability and general acceptance of the procedure accompanied by an aging population of implants. Metal implants are often secured to the tibial plateau by a mantle of poly(methyl methacrylate) bone cement. During revision surgery, a power oscillating saw is used to remove bone cement while preparing the boney bed. Presently, there are no published studies on the mechanics of bone cement removal by a sawing process. The aim of this research was to quantify the effect of blade speed and applied thrust force on the volumetric cutting rate of bone cement. A custom reciprocating saw with variable stroke length was used to conduct a three-factor design of experiments. Two levels, without center-points, were sufficient to model the effect of stroke length (6.75, 10.13 mm), thrust force (11, 19 N), and reciprocating speed in strokes per minute (6000, 8000 SPM) on cutting rate. The results indicate that each of the three parameters had a significant impact on cutting rate (p < 0.001), with a linear relationship between both force and cutting rate (r = 0.98) and blade speed and cutting rate (r = 0.98). For the parameters considered, increasing the reciprocating speed had the most significant effect on cutting rate. For example, while holding force and stroke length constant (11 N, 10.13 mm), an increase in speed from 6000 to 8000 SPM nearly doubled the cutting rate of bone cement. A cutting rate model was developed by regression analysis of the experimental data and validated through additional experiments. The model has applications in haptic feedback for surgical simulators to differentiate between the cutting rates of bone and bone cement during virtual training of resident surgeons.

Economic evaluation of access to musculoskeletal care: the case of waiting for total knee arthroplasty

Background

The projected demand for total knee arthroplasty is staggering. At its root, the solution involves increasing supply or decreasing demand. Other developed nations have used rationing and wait times to distribute this service. However, economic impact and cost-effectiveness of waiting for TKA is unknown.

Methods

A Markov decision model was constructed for a cost-utility analysis of three treatment strategies for end-stage knee osteoarthritis: 1) TKA without delay, 2) a waiting period with no non-operative treatment and 3) a non-operative treatment bridge during that waiting period in a cohort of 60 year-old patients. Outcome probabilities and effectiveness were derived from the literature. Costs were estimated from the societal perspective with national average Medicare reimbursement. Effectiveness was expressed in quality-adjusted life years (QALYs) gained. Principal outcome measures were average incremental costs, effectiveness, and quality-adjusted life years; and net health benefits.

Results

In the base case, a 2-year wait-time both with and without a non-operative treatment bridge resulted in a lower number of average QALYs gained (11.57 (no bridge) and 11.95 (bridge) vs. 12.14 (no delay). The average cost was $1,660 higher for TKA without delay than wait-time with no bridge, but $1,810 less than wait-time with non-operative bridge. The incremental cost-effectiveness ratio comparing wait-time with no bridge to TKA without delay was $2,901/QALY. When comparing TKA without delay to waiting with non-operative bridge, TKA without delay produced greater utility at a lower cost to society.

Conclusions

TKA without delay is the preferred cost-effective treatment strategy when compared to a waiting for TKA without non-operative bridge. TKA without delay is cost saving when a non-operative bridge is used during the waiting period. As it is unlikely that patients waiting for TKA would not receive non-operative treatment, TKA without delay may be an overall cost-saving health care delivery strategy. Policies aimed at increasing the supply of TKA should be considered as savings exist that could indirectly fund those strategies.