A new prediction model for patient satisfaction after total knee arthroplasty and the roles of different scoring systems: a retrospective cohort study

Patient Satisfaction Is Nearly 90% After Total Knee Arthroplasty; We Are Better Than We Were

BACKGROUND

Total knee arthroplasty (TKA) is frequently performed to reduce pain and improve quality of life. Patient satisfaction following TKA is commonly reported at 80%. However, given recent advancements in perioperative management, implants, and operative techniques, new assessments on patient satisfaction are warranted.

METHODS

Patients who underwent unilateral or bilateral TKA between November 2018 and December 2023 and used a web-based home therapy program were included. In total, 1,702 patients with 1,527 (89.7%) reporting satisfaction following TKA were included. Patients were stratified by satisfaction with postoperative outcomes. Univariate analyses were performed on demographics and patient-reported outcomes. Multivariate logistic regression analyses were performed to identify parameters predictive of postoperative satisfaction with TKA.

RESULTS

Satisfied patients had higher mean age, body mass index (BMI), and hypertension (all P = 0.05). Throughout the entire cohort, Patient-Reported Outcomes Measurement Information System (PROMIS), Knee Injury and Osteoarthritis Outcome Score Junior (KOOS Jr), and visual analog scale pain scores improved from preoperatively to 1 year postoperatively (P < 0.001). Preoperatively, satisfied patients reported higher PROMIS overall, PROMIS mental, and KOOS Jr scores (all P < 0.05). At one year postoperatively, satisfied patients noted larger improvements in all functional outcomes, thus resulting in better PROMIS overall, PROMIS physical, PROMIS mental, KOOS Jr, and visual analog scale pain scores (all P < 0.001). Multivariate logistic regression analyses revealed that only age (odds ratio = 1.0, P = 0.005) and BMI (odds ratio = 1.0, P = 0.006) were predictive of satisfaction after TKA procedure.

CONCLUSIONS

In a modern cohort of TKA patients, nearly 90% reported satisfaction following surgery. Satisfied patients had higher preoperative and postoperative functional outcome scores. Older age and BMI were strongly predictive of postoperative satisfaction. Although careful preoperative selection of patients should still be employed, patient satisfaction following TKA may be higher than commonly reported.

Time-Driven Activity-Based Cost Analysis to Decrease Financial Burden of Manipulation Under Anesthesia after Total Knee Arthroplasty

BACKGROUND

Despite total knee arthroplasty (TKA) being considered one of the most successful orthopaedic procedures, stiffness may lead to dissatisfaction. Manipulation under anesthesia (MUA) is a first-line treatment option for stiffness after TKA. Since patients who have stiffness following TKA often have higher costs, there is a need to understand the cost to the hospital of an MUA. We sought to use Time-Driven Activity-Based Costing (TDABC) to accurately determine MUA hospital costs.

METHODS

Previously collected financial data of 510 knees in 479 patients who underwent MUA after TKA at a single institution between January 07, 2015, and May 23, 2023, were retrospectively reviewed. Demographics, history of TKA, length of stay, and discharge disposition were included to assess for patient-specific risk factors related to increased cost of MUA. The TDABC costs, including all personnel and supply costs, were calculated and compared to the hospital reimbursement for each patient.

RESULTS

The average total cost of an MUA was 1,749.72 dollars ($). Personnel costs accounted for 71.4% of total costs. Commercial insurance plans were associated with a higher cost of MUA (P = 0.048), but age (P = 0.081), sex (P = 0.18), body mass index (P = 0.11), or American Society of Anesthesiologists score (P = 0.88) were not. Mean hospital reimbursement was $1,909.18, and mean hospital revenue was $159.46.

CONCLUSION

The MUAs have substantial hospital costs, with most expenses coming from preoperative testing and procedural personnel costs. The majority of MUAs occurred within the 90-day TKA global payment period, which is important to consider for hospital reimbursement policies.

A clinical risk score enables early prediction of dissatisfaction 1 year after total knee arthroplasty

PURPOSE

Dissatisfaction after total knee arthroplasty (TKA) is a prevalent and clinically relevant problem that affects approximately 10%-20% of patients. The aim of this study is to identify factors associated with dissatisfaction 1 year after TKA.

METHODS

A total of 236 patients undergoing TKA were included in this prospective cohort study. Demographic data, preoperative clinical parameters (e.g., axial alignment, osteoarthritis severity) and patient-reported outcome measures (PROMs) were collected preoperatively, at 1 month and 1 year after TKA, encompassing the Knee Society Score (KSS) and Knee injury and Osteoarthritis Outcome Score (KOOS). The primary outcome was dissatisfaction 1 year after TKA, defined as ≤20 points on the KSS satisfaction scale. A risk score based on multiple regression and area under the curve (AUC) analyses was calculated to predict dissatisfaction.

RESULTS

One year after TKA, 16% of the patients were dissatisfied. Dissatisfied patients were significantly younger (p = 0.023) and had a higher body mass index (BMI) (p = 0.007). No differences were observed in preoperative objective (p = 0.903) and functional KSS (p = 0.346), pain (p = 0.306), osteoarthritis severity (p = 0.358), axial knee alignment (p = 0.984) or psychological distress (p = 0.138). The likelihood of dissatisfaction at 1 year was 3.0, 4.0, 7.4, 4.3 and 2.8 times higher amongst patients aged <63.5 years, with a BMI > 30.1 kg/m2, a KOOSPain < 50%, a KSSFunction < 42 points and a KSSExpectation < 9 points (all at 1 month), respectively. Using these variables, a risk score with a maximum of 7 points was developed, demonstrating a high predictive value for dissatisfaction (AUC: 0.792 [95% confidence interval: 0.700-0.884], p < 0.001).

CONCLUSION

Dissatisfaction 1 year after TKA can be predicted by a weighted risk score that includes patient age, BMI, pain, subjective functionality and unmet expectation 1 month postoperatively. Using the risk score, early detection of dissatisfaction has the potential to enable targeted interventions and improve patients' quality of life.

LEVEL OF EVIDENCE

Level II, Prognostic study.

The third gap - The forgotten space in total knee arthroplasty

AIMS

Total Knee Arthroplasty (TKA) aims to leave the proximal flange of the femoral component flush with the femoral cortex. Manually, the requisite plane is found using the anterior femoral cortex or the intramedullary canal, whereas navigation uses hip and knee centre. Presently, no system prioritises restoration of the third space or native trochlear groove height (TGH) and there is a deficiency of published data on the variation of TGH with respect to the anterior cortex. This study aims to address this deficit. Hypothetically, restoration of the third space occurs when trochlear component depth equals TGH.

MATERIALS AND METHODS

Relative to the posterior femoral axis the height of the anterior femoral cortex is higher laterally than centrally. For simplicity, this study reports MRI measurements of TGH relative to the centre in 110 normal subjects.

RESULTS

TGH varied from the anterior femoral cortex by a mean of 2.32 mm (standard deviation, SD 1.77 mm, range -1.50 mm to 6.80 mm). If a femoral component trochlear depth of 2.2 mm is assumed, then 24.5% would be either over- or understuffed by more than 2 mm.

CONCLUSION

There is significant variation in TGH relative to the anterior femoral cortex. Assuming a femoral component trochlear depth of 2.2 mm, approximately one quarter of patients (24.5%) will be over- or understuffed by more than 2 mm. Variation in femoral component flexion and extension combined with whether or not it is left proud or notched will add further variation. Failure to restore the third space is likely to contribute to unsatisfactory results following TKA. Future surgical workflows should address this.

Impact of motivational feedback on levels of physical activity and quality of life by activity monitoring following knee arthroplasty surgery-protocol for a randomized controlled trial nested in a prospective cohort (Knee-Activity)

BACKGROUND

Evidence on how to improve daily physical activity (PA) levels following total knee arthroplasty (TKA) or medial uni-compartmental knee arthroplasty (mUKA) by motivational feedback is lacking. Moreover, it is unknown whether a focus on increased PA after discharge from the hospital improves rehabilitation, physical function, and quality of life. The aim of this randomized controlled trial (RCT) nested in a prospective cohort is (a) to investigate whether PA, physical function, and quality of life following knee replacement can be increased using an activity monitoring device including motivational feedback via a patient app in comparison with activity monitoring without feedback (care-as-usual), and (b) to investigate the potential predictive value of PA level prior to knee replacement for the length of stay, return to work, and quality of life.

METHODS

The study is designed as a multicenter, parallel-group, superiority RCT with balanced randomization (1:1) and blinded outcome assessments. One hundred and fifty patients scheduled for knee replacement (TKA or mUKA) will be recruited through Odense University Hospital, Denmark, Vejle Hospital, Denmark and Herlev/Gentofte Sygehus, Denmark. Patients will be randomized to either 12 weeks of activity monitoring and motivational feedback via a patient app by gamification or 'care-as-usual,' including activity monitoring without motivational feedback. The primary outcome is the between-group change score from baseline to 12-week follow-up of cumulative daily accelerometer counts, which is a valid proxy for average objectively assessed daily PA.

DISCUSSION

Improving PA through motivational feedback following knee replacement surgery might improve post-surgical function, health-related quality of life, and participation in everyday life.

TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT06005623. Registered on 2023-08-22.

TRIAL STATUS

Recruiting.

Patient Demographic Factors Impact KOOS JR Response Rates for Total Knee Arthroplasty Patients

The Knee injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR) is a validated patient-reported measure for assessing pain and function following total knee arthroplasty (TKA). This study investigates how patient demographic factors (i.e., age, sex, and race) correlate with KOOS JR response rates. This was a retrospective cohort study of adult, English-speaking patients who underwent primary TKA between 2017 and 2023 at an academic institution. KOOS JR completion status-complete or incomplete-was recorded within 90 days postoperatively. Standard statistical analyses were performed to assess KOOS JR completion against demographic factors. Among 2,883 total patients, 70.2% had complete and 29.8% had incomplete KOOS JR questionnaires. Complete status (all p < 0.01) was associated with patients aged 60 to 79 (71.8%), white race (77.6%), Medicare (81.7%), marriage (76.8%), and the highest income quartile (75.7%). Incomplete status (all p < 0.001) was associated with patients aged 18 to 59 (64.4%), Medicaid (82.4%), and lower income quartiles (41.6% first quartile, 36.8% third quartile). Multiple patient demographic factors may affect KOOS JR completion rates; patients who are older, white, and of higher socioeconomic status are more likely to participate. Addressing underrepresented groups is important to improve the utility and generalizability of the KOOS JR.

Radiological measurement of posterior tibial subluxation as a preoperative factor in choosing the type of implant in primary total knee arthroplasty

Introduction

Total knee arthroplasty (TKA) is the most effective treatment of late osteoarthritis (OA) and is considered among the most successful surgical procedures in general. However, about 20% of patients remain dissatisfied. An important aspect of TKA is the proper choice of implant type - posterior stabilized (PS) or cruciate retaining (CR). Both have their indications for use based on intraoperative functional examination, but no objective radiological criteria have yet been developed. The aim of this study was to investigate the relationship between the posterior subluxation of the tibia on preoperative radiograms and implant type used.

Material and methods

A series of 52 patients undergoing TKA were included in the study. All patients were over 50 years old, had clinically and radiologically confirmed primary OA of grade IV on the Kellgren-Lawrence scale and were undergoing a primary total knee replacement (TKR) with a PS or CR design. Preoperative lateral radiographs were analysed retrospectively. The tibial translation ratio was calculated as a percentage of subluxation in the length of the tibial plateau.

Results

There were no significant differences between implant types in regard to investigated parameters. However, there was a significant difference between the groups CR and PS in regard to age (68.5 [60.0-72.0] vs. 72.5 [68.0-75.0], p = 0.006).

Conclusions

This study revealed that preoperative tibial translation does not significantly correlate with the choice of implant type and so probably not with posterior cruciate ligament (PCL) function and efficiency either. Additionally, this study showed that PCL insufficiency is related to the age of the patients, because of the more frequent choice of the PS implant type for the surgery in older patients than in the case of the CR implant type.

Randomized Placebo-Controlled Trial of 60-Day Percutaneous Peripheral Nerve Stimulation Treatment Indicates Relief of Persistent Postoperative Pain, and Improved Function After Knee Replacement

OBJECTIVES

Total knee arthroplasty (TKA) is an effective surgery for end-stage knee osteoarthritis, but chronic postoperative pain and reduced function affect up to 20% of patients who undergo such surgery. There are limited treatment options, but percutaneous peripheral nerve stimulation (PNS) is a promising nonopioid treatment option for chronic, persistent postoperative pain. The objective of the present study was to evaluate the effect of a 60-day percutaneous PNS treatment in a multicenter, randomized, double-blind, placebo-controlled trial for treating persistent postoperative pain after TKA.

MATERIALS AND METHODS

Patients with postoperative pain after knee replacement were screened for this postmarket, institutional review board-approved, prospectively registered (NCT04341948) trial. Subjects were randomized to receive either active PNS or placebo (sham) stimulation. Subjects and a designated evaluator were blinded to group assignments. Subjects in both groups underwent ultrasound-guided placement of percutaneous fine-wire coiled leads targeting the femoral and sciatic nerves on the leg with postoperative pain. Leads were indwelling for eight weeks, and the primary efficacy outcome compared the proportion of subjects in each group reporting ≥50% reduction in average pain relative to baseline during weeks five to eight. Functional outcomes (6-minute walk test; 6MWT and Western Ontario and McMaster Universities Osteoarthritis Index) and quality of life (Patient Global Impression of Change) also were evaluated at end of treatment (EOT).

RESULTS

A greater proportion of subjects in the PNS groups (60%; 12/20) than in the placebo (sham) group (24%; 5/21) responded with ≥50% pain relief relative to baseline (p = 0.028) during the primary endpoint (weeks 5-8). Subjects in the PNS group also walked a significantly greater distance at EOT than did those in the placebo (sham) group (6MWT; +47% vs -9% change from baseline; p = 0.048, n = 18 vs n = 20 completed the test, respectively). Prospective follow-up to 12 months is ongoing.

CONCLUSIONS

This study provides evidence that percutaneous PNS decreases persistent pain, which leads to improved functional outcomes after TKA at EOT.

Capability After Total Knee Arthroplasty for Osteoarthritis Is Strongly Associated With Preoperative Symptoms of Depression

BACKGROUND

Primary total knee arthroplasty (TKA) aims to improve the level of capability (ability to perform valued life activities) associated with knee osteoarthritis (OA). However, some evidence suggests a substantial proportion of patients remain dissatisfied with their outcomes after this procedure. We sought to better understand the association between mental health, specifically symptoms of depression, with postoperative outcomes. Symptoms of depression are shown to be common among orthopaedic populations in general and can be briefly and conveniently evaluated using the Patient Health Questionnaire-2 (PHQ-2) in a less burdensome manner compared with longer mental health surveys. This study assesses the association between preoperative depressive symptoms (PHQ-2) and levels of capability at 6 weeks and 6 months after TKA.

METHODS

We conducted a prospective cohort study involving 114 patients with knee OA across five clinics in California and Texas scheduled for TKA. Participants completed a preoperative PHQ-2 and Knee Injury and OA Outcome Score for Joint Replacement (KOOS JR) survey at 6 weeks and 6 months post-TKA. We analyzed these data using bivariate and multivariable regression.

RESULTS

Preoperative PHQ-2 scores were significantly associated with lower KOOS JR scores at 6 weeks and 6 months post-TKA. Latino/Hispanic race was also associated with lower KOOS JR scores at 6 weeks. The association between preoperative depressive symptoms and level of capability after TKA were more pronounced at 6 months compared with 6 weeks.

CONCLUSION

Preoperative symptoms of depression are strongly associated with reduced capability after TKA and can be screened for using the PHQ-2-a brief tool that can be feasibly incorporated into clinical workflows. User-friendly assessment of depressive symptoms can assist orthopaedic surgeons in identifying and addressing mental health at the outset during the management of knee OA.

The development of machine learning algorithms that can predict patients satisfaction using baseline characteristics, and preoperative and operative factors of total knee arthroplasty

BACKGROUND

Patient satisfaction following primary total knee arthroplasty (TKA) is a crucial part to evaluate the success of the procedure. The purpose of this study was to develop to predict patient satisfaction following TKA.

METHODS

Satisfaction outcome data after 435 consecutive conventional TKAs performed between August 2020 and December 2021 were retrospectively collected. The total 26 input data were collected. The most favorable algorithm was first found using logistic regression (LR) and machine learning (ML) algorithms. To evaluate the predictive performance of the models, both area under curve (AUC) and F1-score were used as the primary metrics. The shapley additive explanations (SHAP) feature explanation in XGBoost and LR analysis were performed to interpret the model.

RESULTS

The performance of extreme gradient boosting classifier (XGBoost) was only higher than that of conventional LR in AUC (0.782 vs. 0.689). Comparing the F-1 score, only XGBoost showed better performance than LR (0.857 vs. 0.800). The most predictive feature in XGBoost was Short Form-36 physical and mental component summary scores (SF-36 MCS), followed by Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain, Bone mineral density (BMD). In the LR analysis, lumbar spine disease, WOMAC pain, and BMD were statistically significant.

CONCLUSION

XGboost showed the best performance and was superior to conventional LR in the prediction of patient satisfaction after TKA. The SF-36 MCS was the most important feature in the ML model. WOMAC pain and BMD were meaningful variables and demonstrated a linear relationship with satisfaction in both the LR and ML models.

LEVEL OF EVIDENCE

Retrospective cohort study; Level of evidence 3.

Does preoperative 3D CT planning helps in predicting the component size determination and alignment in automatic robotic total knee arthroplasty (RA-TKA)

Purpose

Image-based Robotic Total knee Arthroplasty (RA-TKA)was developed with the purpose of enhancing the accuracy in determining the component sizes preoperatively and helping surgeons in minimizing errors and improve patient outcomes. The research aims to find the reliability of robotic-assisted TKR based on images in determining the correct component sizes using preoperative three-dimensional (3D) computer tomography.

Method

After ethical approval, we conducted a prospective study from March 2022 to December 2022. A total of 100 knees underwent image-based RA-TKA having grade 4 Osteoarthritis knee (Kellegren Lawrence classification). A single senior surgeon performed on all patients. Postoperative implant sizes and fit were assessed by five radiographic markers by an independent observer.

Results

In our study, we found the mean age was (64.96 ± 7.3) years, with female to male ratio of 43:22. The preoperative 3D CT accuracy is 100% for femoral component sizing and 97% for the tibial component. There was a statistically significant improvement in varus deformity from preoperative 7.370 ± 3.70° to 1.24 0 ± 0.910° after surgery., p = 0.001. Improvement in flexion deformity correction was from preoperative 6.50 ± 6.30 to postoperative 1.640 ± 1.770, p = 0.001.

Conclusion

Our study concludes that the use of pre-operative 3D CT helps in predicting the component sizes, minimizes surgical time, and enhances implant position accuracy, as well as improves postoperative limb alignment in the coronal and sagittal planes.

Artificial intelligence-based applications in shoulder surgery leaves much to be desired: a systematic review

Background

Artificial intelligence (AI) aims to simulate human intelligence using automated computer algorithms. There has been a rapid increase in research applying AI to various subspecialties of orthopedic surgery, including shoulder surgery. The purpose of this review is to assess the scope and validity of current clinical AI applications in shoulder surgery literature.

Methods

A systematic literature review was conducted using PubMed for all articles published between January 1, 2010 and June 10, 2022. The search query used the terms as follows: (artificial intelligence OR machine learning OR deep learning) AND (shoulder OR shoulder surgery OR rotator cuff). All studies that examined AI application models in shoulder surgery were included and evaluated for model performance and validation (internal, external, or both).

Results

A total of 45 studies were included in the final analysis. Eighteen studies involved shoulder arthroplasty, 13 rotator cuff, and 14 other areas. Studies applying AI to shoulder surgery primarily involved (1) automated imaging analysis including identifying rotator cuff tears and shoulder implants (2) risk prediction analyses including perioperative complications, functional outcomes, and patient satisfaction. Highest model performance area under the curve ranged from 0.681 (poor) to 1.00 (perfect). Only 2 studies reported external validation.

Conclusion

Applications of AI in the field of shoulder surgery are expanding rapidly and offer patient-specific risk stratification for shared decision-making and process automation for resource preservation. However, model performance is modest and external validation remains to be demonstrated, suggesting increased scientific rigor is warranted prior to deploying AI-based clinical applications.

Distribution of Coronal Plane Alignment of the Knee Classification in Patients with Knee Osteoarthritis in Japan

Coronal plane alignment of the knee (CPAK) has recently been proposed as a simple and universal classification system to determine the suitability of a particular phenotype of the knee to a specific alignment strategy for knee replacement surgery. Although racial differences may affect knee alignment, there are no reports on the racial distribution of this classification system. We aimed to clarify the distribution of CPAK classification in patients with osteoarthritis who underwent total knee arthroplasty (TKA) in Japan. Consecutive patients who underwent primary TKA were analyzed retrospectively. The knees were categorized according to the CPAK classification system which comprised of two independent variables (arithmetic hip-knee-ankle [aHKA] angle and joint-line obliquity [JLO]) with three respective subgroups to create the following nine phenotypes of the knee: type I (varus aHKA and apex distal JLO), type II (neutral aHKA and apex distal JLO), type III (valgus aHKA and apex distal JLO), type IV (varus aHKA and neutral JLO), type V (neutral aHKA and neutral JLO), and type VI (valgus aHKA and neutral JLO), type VII (varus aHKA and apex proximal), type VIII (neutral aHKA and apex proximal), and type IX (valgus aHKA and apex proximal). The distribution of the phenotypes in the Japanese population was investigated as a primary outcome. To accurately compare the results with previous studies conducted on non-Japanese patients, a sex-matched distribution was investigated as a secondary outcome. A total of 570 knees were investigated of which 500 knees were examined after exclusions. The most common distribution was type I (53.8%), followed by type II (25.4%), type III (8.2%), type IV (7.2%), type V (4.4%), and type VI (1.0%). Types VII, VIII, and IX were not distributed. The sex-matched distribution was nearly identical to the overall distribution in Japan. The majority of patients with knee osteoarthritis in Japan had medially tilted joints with constitutional varus alignment.