Custom total knee arthroplasty combined with personalised alignment grants 94% patient satisfaction at minimum follow-up of 2 years

Custom total knee arthroplasty with personalised alignment showed better 2-year functional outcome compared to off-the-shelf arthroplasty

PURPOSE

Customised individually made (CIM) total knee arthroplasty (TKA) with personalised alignment is relatively new and evidence is limited. The aim of this study was to compare patient-reported outcome measures between CIM and off-the-shelf (OTS) TKA patients in a matched-pair analysis with a 2-year follow-up.

METHODS

In this single-centre, prospective cohort study, propensity score matching was performed on 51 CIM and 51 OTS TKA. Data were measured at baseline, at 4 months, 1 and 2 years and included the Forgotten Joint Score (FJS-12), the High Activity Arthroplasty Score (HAAS), the Knee injury and Osteoarthritis Outcome Score (KOOS), the EQ-5D-3L, the EQ-Visual Analogue Scale, satisfaction, overall knee improvement, willingness to undergo the surgery again and the Knee Society Score.

RESULTS

At 2 years follow-up, the FJS-12 (77 vs. 67, p = .058), HAAS (13 vs. 11, p < .001), KOOS daily living (92 vs. 86, p = .029), KOOS sport (76 vs. 65, p = .019), KOOS quality of life (81 vs. 71, p = .028) and the EQ-5D (.95 vs. .90, p = .030) were higher for CIM TKA compared to OTS TKA. Satisfaction rate was 92% for CIM TKA and 84% for OTS TKA (p = .357). Most patients reported an improvement in the overall knee state (94% CIM and 90% OTS, p = .487) and almost all patients would undergo the surgery again (96% CIM and 98% OTS, p = .999).

CONCLUSION

The current study found that CIM TKA patients had better functional outcomes at 2 years. Patient satisfaction was high and not statistically significantly different from OTS TKA patients.

LEVEL OF EVIDENCE

Level II prospective cohort study.

High Expectations Among Patients Who Have Undergone TKA Do Not Correlate With Satisfaction

BACKGROUND

One of five patients is dissatisfied with the outcome of TKA. With the increasing number of TKAs, this affects many patients. It has been suggested that high expectations may influence satisfaction, but the relationship between preoperative patient expectations and postoperative patient satisfaction remains poorly understood.

QUESTIONS/PURPOSES

(1) Are preoperative patient expectations correlated with postoperative satisfaction? (2) Are expectations correlated with patient characteristics or patient-reported outcome measures (PROMs)? (3) Is satisfaction correlated with patient characteristics or PROMs? (4) Do patients report specific items as more relevant to their expectations?

METHODS

This was a single-center, observational, retrospective, comparative study involving patients who underwent TKA. Between December 2020 and June 2022, three senior surgeons performed 306 TKAs. Of these, 76% (234) had the preoperative PROMs required for this study, and of these, 82% (193) had completed PROMs at the 12-month follow-up interval and were analyzed. Of the 193 included patients, 53% (102) were women; the mean age was 68 ± 9 years. Data were collected at baseline, 4 months, and 12 months. Twelve months of follow-up has been shown to be adequate in studies with PROMs. Patient expectations were measured using the validated Hospital for Special Surgery Knee Replacement Expectation Survey on a scale from 0 to 100, with higher scores indicating higher expectations. We also assessed patient satisfaction, the Knee injury and Osteoarthritis Outcome Score, Forgotten Joint Score, High-Activity Arthroplasty Score, EQ-5D-3L, and the objective Knee Society Score. Bivariate linear correlations were analyzed using the Pearson or Spearman test.

RESULTS

Preoperative patient expectations did not correlate with postoperative satisfaction. The mean Hospital for Special Surgery Knee Replacement Expectation Survey score was 82 ±16 points and did not correlate with satisfaction at either 4 months (r = -0.061; p = 0.42) or 12 months (r = -0.126; p = 0.11). Expectations did not correlate with patient characteristics or any of the preoperative or postoperative PROMs or the Knee Society Score. Patient satisfaction was 88% (158 of 179) at 4 months and 83% (160 of 193) at 12 months and did not correlate with patient characteristics or any of the preoperative PROMs or Knee Society Score. Patient satisfaction was medium to strongly correlated with postoperative PROMs and Knee Society Score. The Hospital for Special Surgery Knee Replacement Expectation Survey items with the most frequent expected improvement were "ability to walk" (99% [192 of 193]), "go downstairs" (99% [191 of 192]), and "go upstairs" (99% [192 of 193]).

CONCLUSION

Preoperative expectations were not correlated with postoperative satisfaction or PROMs. Surgeons should be aware that patients have high expectations. However, these expectations appear to be less relevant in determining postoperative satisfaction.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient-acceptable symptom state (PASS) in patients who have undergone total knee arthroplasty: a systematic review

BACKGROUND

The present systematic review investigated the minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient-acceptable symptom state (PASS) of several frequent and established PROMs used to assess patients who have undergone TKA. This study was conducted according to the 2020 PRISMA statement.

METHODS

In September 2023, PubMed, Web of Science, and Embase were accessed with no time constraint All clinical studies investigating tools to assess the clinical relevance of PROMs used to evaluate patients having received TKA were accessed. Only studies which evaluated the MCID, PASS, or SCB were eligible. The PROMs of interest were the Forgotten Joint Score-12 (FJS-12), the Oxford Knee Score (OKS), the Knee Injury and Osteoarthritis Outcome Score (KOOS) and its related subscales activity of daily living (ADL), pain, quality of life (QoL), sports and recreational activities, and symptoms, the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) score, the Knee Society Score (KSS) and related function score, and the Short Form-12 (SF-12) and Short Form-36 (SF-36).

RESULTS

Data from 29,737 patients were collected. The overall risk of bias was low to moderate. The great variability of thresholds for MCID, SCB and PASS between questionnaires but also between investigated aspects was noted, whereby MCIDs for the SF-36 appear lower than for knee-specific questionnaires.

CONCLUSION

Despite its critical role from a patient's perspective, the dimension of SCB is still neglected in the literature. Moreover, thresholds for the different concepts need to be condition-specific. We encourage authors to specifically report such data in future studies and to adhere to previously reported definitions to allow future comparison. Level of evidence Level IV, systematic review and meta-analysis.

Five or more gender- and size-diverse customizations of distal femur prostheses are needed to improve fit for Chinese knees

PURPOSE

Mismatch between partial imported prostheses and Chinese anatomy affects the clinical outcome of the procedure. The purpose of this study was to measure the anatomical dimensions of Chinese distal femurs to provide guidance for the design of more compatible distal femoral prostheses.

METHODS

A total of 406 healthy distal femurs were reconstructed and measured. Consistency of these measurements and differences in sides, gender, and populations were examined. Parameter correlations were analyzed, and pairs with strong correlations underwent linear regression analysis. The design of distal femoral prostheses was referenced from the results of K-means and hierarchical clustering analysis.

RESULTS

Ten parameters were measured, including the trans-epicondylar axis, width of the distal femur (ML), anteroposterior diameter of the distal femur (AP), etc. The intra-class correlation coefficient ranged from 0.795 to 0.999 for intra-observer consistency, and from 0.796 to 0.998 for inter-observer consistency. Males exhibited significantly larger parameters than females, except for the posterior condylar angle (all P values < 0.05). Compared to other populations, substantial differences were observed for most parameters, such as ML, AP, width of lateral femoral condyle, etc. (all P values < 0.05). Clustering analysis suggested that distal femoral prostheses should include at least five sizes to adequately accommodate the sampled population. ML sizes for males were 68, 70, 83, 73, and 89 mm, and for females 64, 65, 71, 67, and 77 mm. AP sizes for males were 56, 60, 60, 64, and 64 mm, and for females 48, 52, 54, 57, and 58 mm.

CONCLUSIONS

Chinese distal femur morphology, as analyzed using 3D techniques, varies significantly between genders and when compared with international data. For improved patient fit, the creation of five or more distal femur prostheses, diversified by gender and size and informed by the associated morphological parameters, is recommended.

LEVEL OF EVIDENCE

IV.

Satisfaction after total knee arthroplasty: a prospective matched-pair analysis of patients with customised individually made and off-the-shelf implants

PURPOSE

Customised individually made (CIM) total knee arthroplasty (TKA) was introduced to potentially improve patient satisfaction and other patient-reported outcome measures (PROMs). The purpose of this study was to compare PROMs, especially patient satisfaction, of patients with CIM and OTS TKA in a matched-pair analysis with a 2-year follow-up.

METHODS

This is a prospective cohort study with a propensity score matching of 85 CIM and 85 off-the-shelf (OTS) TKA. Follow-up was at 4 months, 1 year and 2 years. The primary outcome was patient satisfaction. Secondary outcomes were as follows: overall improvement, willingness to undergo the surgery again, Knee injury and Osteoarthritis Outcome Score (KOOS), Forgotten Joint Score (FJS-12), High-Activity Arthroplasty Score (HAAS), EQ-5D-3L, EQ-VAS, Knee Society Score (KSS) and surgeon satisfaction.

RESULTS

Patient satisfaction ranged from 86 to 90% and did not differ between CIM and OTS TKA. The EQ-VAS after 4 months and the HAAS after 1 year and 2 years were higher for CIM TKA. KOOS, FJS-12 and EQ-5D-3L were not different at follow-up. The changes in KOOS symptoms, pain and daily living were higher for OTS TKA. The KSS was higher for patients with CIM TKA. Surgeon satisfaction was high throughout both groups. Patients who were satisfied after 2 years did not differ preoperatively from those who were not satisfied. Postoperatively, all PROMs were better for satisfied patients. Patient satisfaction was not correlated with patient characteristics, implant or preoperative PROMs, and medium to strongly correlated with postoperative PROMs.

CONCLUSION

Patient satisfaction was high with no differences between patients with CIM and OTS TKA. Both implant systems improved function, pain and health-related quality of life. Patients with CIM TKA showed superior results in demanding activities as measured by the HAAS.

LEVEL OF EVIDENCE

II, prospective cohort study.