What do patients want out of their Total Knee Arthroplasty?: An Indian perspective

Prasad A, Rajan DV. Estimation of adductor ratio in the Indian population: Is it a reliable indicator for recreating joint line of the knee?

Background

Accurate restoration of the joint line is critical in revision total knee arthroplasty (r-TKA) to ensure proper ligament tension and optimize functional outcomes.

Objective

To determine the adductor ratio in the Indian population and assess its reliability for restoring the joint line in primary total knee arthroplasty (TKA).

Methods

The study consisted of two parts. In the first part, 93 young, non-arthritic individuals were evaluated radiologically to estimate the adductor ratio. In the second part, 47 patients with grade IV osteoarthritis undergoing primary TKA were included. Pre-operative radiographic and intraoperative calliper measurements of the adductor tubercle to joint line distance (ATJL) and femoral width (FW) were taken. Pearson correlation was estimated between FW and ATJL, and Bland-Altman analysis was used to assess the agreement between pre-operative and intra-operative measurements. The error in using a standard adductor ratio was estimated.

Results

The mean adductor ratio in the non-arthritic population was 0.542, with a strong correlation between ATJL and FW (r = 0.81, p < 0.001). In the second part, the mean adductor ratio was consistent pre-operatively (0.53) and intra-operatively (0.54), with a bias of 0.001 and 95 % limits of agreement from -0.062 to 0.065. The estimated ATJL was within 5 mm of the actual measurement in 95 % of cases.

Conclusion

The adductor ratio of 0.54 is a reliable indicator for joint line restoration in the Indian population. Documentation of ATJL and FW during primary TKA is recommended for enhancing accuracy in joint line reconstruction in revision scenarios.

Gap Balancing Technique With Functional Alignment in Total Knee Arthroplasty Using the Cuvis Joint Robotic System: Surgical Technique and Functional Outcome

Introduction The application of robotic technologies in total knee arthroplasty (TKA) has widely grown in the past few years. The preoperative CT (computed tomography) scan planning of the knee along with the quantitative soft tissue information recorded and assessed by the robot can be utilized in achieving functional alignment and aid in gap balancing. Gap tension is an important factor influencing the clinical outcome after TKA. This paper describes our technique for gap balancing and functional alignment using a fully autonomous Cuvis joint robotic system. Methods A total of 624 knees underwent primary TKA using Cuvis robotic assistance in the time period between November 2023 to April 2024. A total of 360 patients that included 100 males and 260 females were included in the study. All the surgeries were performed by the same surgeon and the same posterior-stabilized (PS)-design prosthesis was implanted. The medial and lateral gaps were balanced using our technique intraoperatively. The patients were followed up at one, three, and six months duration postoperatively, and their knee functional outcomes were analyzed using the Oxford Knee Score (OKS). Results A total of 360 patients with a mean age of 64.36 were part of this study. The study shows significant improvement in knee function post surgery. The average preoperative OKS recorded was 15.82, which improved at the postoperative sixth-month follow-up to a mean value of 42.07. There were no patients with poor results as per OKS scores, and no patients required any revision procedures. Conclusion The gap balancing technique with functional knee alignment using the Cuvis joint robotic system improved short-term outcomes, with balanced gaps, controlled alignment, and preserved soft tissue tension. No complications were reported, but further long-term, multicenter studies are needed for definitive conclusions.

WOMAC, Kujala Score, and Knee Injury and Osteoarthritis Outcome Score for Quality of Life Thresholds for Predicting Increased and Decreased Likelihood of Failure to Improve Quality of Life After Total Knee Replacement

Background Improvement in quality of life is the primary goal following total knee arthroplasty (TKA). Patient-reported outcome measures (PROMs) have become the standard for evaluating TKA results, capturing the patient's perspective. However, PROMs face challenges such as inconsistent presurgery data collection and ambiguity in determining clinical significance. Establishing reliable thresholds for success and failure is crucial for comparing outcomes. Purpose To determine cutoff values for the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Kujala score, and Knee Injury and Osteoarthritis Outcome Score for Quality of Life (KOOS-QL) that significantly change the likelihood of success (TIS) or failure (TIF) to improve self-reported quality of life one year after TKA compared to the baseline probability of the studied cohort. Methods A retrospective study was conducted to evaluate PROMs following conventional cruciate-retaining (CR) TKA without patellar replacement. Patients were evaluated during 2022 and 2023, with a minimum one-year follow-up. A total of 161 successful evaluations were identified, representing 81% of all CR TKA procedures without patellar replacement performed between January 2018 and June 2022 at a single university hospital. Assessments included the three dimensions of the WOMAC scale (pain, stiffness, and function), Kujala score, and KOOS-QL. The primary outcome was to determine the threshold value of each PROM that significantly reduced or increased the likelihood of "same or worse" self-perceived improvement in quality of life compared to the cohort. Logistic regression with 200 iterations was used for statistical analysis. Results The threshold for improvement success was <4 for WOMAC-Pain, <1 for WOMAC-Stiffness, <15 for WOMAC-Function, >70 for Kujala, and >62 for KOOS-QL. Meanwhile, the threshold for increased failure was >7 for WOMAC-Pain, >3 for WOMAC-Stiffness, >26 for WOMAC-Function, <55 for Kujala, and <41 for KOOS-QL. Conclusions The study successfully established significant thresholds for success and failure in improving quality of life following CR TKA without patellar replacement. The identified thresholds for WOMAC-Pain, WOMAC-Function, and Kujala scores have good-excellent discrimination and can be confidently used to estimate sample sizes and compare quality of life improvements post-TKA.

Deficient gait function despite effect index of the Western Ontario and McMaster university osteoarthritis index score considered cured one year after bilateral total knee arthroplasty

BACKGROUND

To clarify the value of gait analysis and its consistency with traditional scoring scales for the evaluation of knee joint function after total knee arthroplasty (TKA).

METHODS

This study included 25 patients with knee osteoarthritis (KOA) who underwent bilateral TKA, and 25 conditionally matched healthy individuals, categorised into the experimental and control groups, respectively. Patients in the experimental group underwent gait analysis and Western Ontario and McMaster University Osteoarthritis Index (WOMAC) evaluation before and 1 year after TKA. Weight-bearing balance and walking stability were assessed using discrete trends of relevant gait indicators. Pearson's correlation analysis was performed on the gait and WOMAC score data of the experimental group before and after TKA.

RESULTS

One year after TKA, patients' gait indices (except gait cycle) were significantly better than before surgery, but significantly worse than that of the control group (P < 0.01). The shape of patients' plantar pressure curves did not return to normal. Additionally, the discrete trend of related gait indicators reflecting weight-bearing balance and walking stability were smaller than before TKA, but still greater than that of the control group. The WOMAC scores of patients 1 year after TKA were significantly lower than those before TKA (P < 0.001), and the efficacy index was > 80%. The WOMAC scores and gait analysis results were significantly correlated before TKA (P < 0.05).

CONCLUSIONS

Gait analysis should be used in conjunction with scoring scales to assess joint functions.

Anterior knee pain and sit-up tests predicts patients' satisfaction and improvement in quality of life after anterior stabilized total knee replacement without patellar resurfacing

PURPOSE

The purpose of this study was to assess patient satisfaction and identify risk factors for dissatisfaction after anterior stabilised conventional total knee arthroplasty (TKA) without patellar resurfacing, using the Goodman score.

METHODS

We conducted a cross-sectional study using data from our institutional database from 1 January 2018 to 1 March 2021. Patients who underwent TKA with the Vanguard® Cruciate Retaining Anterior Stabilized Knee System (Zimmer Biomet, Warsaw, Indiana, USA) without patellar replacement were included. Patients with other bearing surfaces (posterior stabilised or medial congruent) or diagnosed with infection or instability were excluded. Patients' reported outcomes, body mass index (BMI), passive range of motion, the timed up-and-go test, sit-up test, and algometry were assessed. Patients were also asked if they had anterior knee pain. Satisfaction was assessed using the Goodman scale, and logistic multivariate regression was used to identify variables associated with dissatisfaction and perceived improvement in quality of life.

RESULTS

A total of 131 TKA patients were included in the study. The median satisfaction score was 100 (interquartile range [IQR], 87.5 to 100), with the 75-point threshold at the 90th percentile according to Section A of Goodman. Section B of Goodman showed that 113 TKA patients (86.26%) reported "great improvement" or "more than I ever dreamed." Multivariate logistic regression revealed that anterior knee pain (OR 5.16, 95% CI 1.24 to 21.39), the sit-up test (OR 0.63, 95% CI 0.49 to 0.81), and BMI (OR 0.84, 95% CI 0.70 to 0.99) were significantly associated with patient dissatisfaction and a worse perceived improvement in quality of life. The receiver operating characteristics curve for the models had areas under the curve of 0.83 (95% CI 0.69 to 0.97) and 0.82 (95% CI 0.70 to 0.94), respectively.

CONCLUSION

Anterior stabilised TKA without patellar resurfacing can achieve 90% satisfaction and 86% improvement in quality of life. To improve these results, it is essential to prevent and treat anterior knee pain and enhance quadriceps strength.

LEVEL OF EVIDENCE

Level III (retrospective cohort study).

Early Results of Bone-Conserving High Flexion Posterior-Stabilized Total Knee System in Indian Population

BACKGROUND

A number of total knee arthroplasty (TKA) systems are used across a variety of markets in which outcome will be influenced by patient factors, surgical technique and implant characteristics. The aim of the current study was to report the early functional results of a primary TKA system in support of the component design characteristics adapted for achieving increased functional expectations of the patients.

MATERIALS AND METHODS

A prospective, continuous series of 304 primary posterior-stabilized (PS) TKAs were performed in 208 patients by a single surgeon. Inclusion criterion was patients undergoing primary TKA with Freedom Total Knee system and willing to participate in the study. Exclusion criteria were patients undergoing revision TKA, patients not willing to participate and patients who were lost to follow-up. Patients were clinically and radiologically assessed for a minimum of 5 years post-operatively. Oxford Knee score (OKS) and range of motion (ROM) were assessed for the entire study population and by gender.

RESULTS

There were no patients who were lost to follow-up. Two patients (Two knees) required incision and secondary suturing for superficial skin wound complication. At minimum 5-year follow-up, there was no radiographic evidence of component loosening/failure. Clinical evaluation at 5 years post-operatively showed statistically significant increase in the OKS and ROM as compared to pre-operative values (OKS pre-operative 19.27 ± 1.86, post-operative 38.76 ± 1.5, p value < 0.001, ROM pre-operative 94.57 ± 3.49, post-operative 127.69 ± 3.65, p value < 0.001). There was no statistically significant difference in the clinical outcome between male and female genders as well as between unilateral and bilateral TKA.

CONCLUSION

The study showed encouraging early results for the bone-conserving high flexion TKA system in 208 patients at minimum 5-year follow-up. The adapted design characteristics for improved functional expectations are confirmed in this reported Indian population study group cohort. Further continued evaluation is warranted for this primary TKA system across Indian and other ethnic population.