Predicting clinical outcomes after total knee arthroplasty from preoperative radiographic factors of the knee osteoarthritis

Marginalization Influences Access, Outcomes, and Discharge Destination Following Total Joint Arthroplasty in Canada's Universal Healthcare System

BACKGROUND

The influence of socioeconomic status on outcomes following total joint arthroplasty (TJA) in the Canadian single-payer healthcare system is yet to be elucidated. The objective of the present study was to evaluate the impact of socioeconomic status on TJA outcomes.

METHODS

This was a retrospective review of 7,304 consecutive TJA (4,456 knees and 2,848 hips) performed between January 1, 2001 and December 31, 2019. The primary independent variable was the average census marginalization index. The primary dependent variable was functional outcome scores.

RESULTS

The most marginalized patients in both the hip and knee cohorts had significantly worse preoperative and postoperative functional scores. Patients in the most marginalized quintile (V) showed a decreased odds of achieving a minimal important difference in functional scores at 1-year follow-up (odds ratio [OR] 0.44; 95% confidence interval [CI] [0.20, 0.97], P = .043). Patients in the knee cohort in the most marginalized quintiles (IV and V) had increased odds of being discharged to an inpatient facility with an OR of 2.07 (95% CI [1.06, 4.04], P = .033) and OR of 2.57 (95% CI [1.26, 5.22], P = .009), respectively. Patients in the hip cohort in V quintile (most marginalized) had increased odds of being discharged to an inpatient facility with an OR of 2.24 (95% CI [1.02, 4.96], P = .046).

CONCLUSION

Despite being a part of the Canadian universal single-payer healthcare system, the most marginalized patients had worse preoperative and postoperative function, and had increased odds of being discharged to another inpatient facility.

LEVEL OF EVIDENCE

IV.

The impact of postoperative inclination of the joint line on clinical outcomes in total knee arthroplasty using a prosthesis with anatomical geometry

The goal of this study was to investigate the impact of postoperative inclination of the joint line on clinical results after total knee arthroplasty (TKA) using a prosthesis with anatomical geometry. This study included 145 primary cruciate-retaining type of knee prosthesis with anatomical geometry. Three years postoperatively, clinical outcomes including the patient-reported outcomes (PROs) were recorded. Limb alignment was evaluated by the hip-knee-ankle (HKA) axis and inclination of the joint line was assessed by the joint line orientation angle (JLOA). Knees were divided into two groups according to the HKA: in-range (- 3 to 3°) and outlier group (< - 3° or > 3°) or the JLOA: in-range (2-4°) and outlier group (< 2° or > 4°), and clinical outcomes were compared between the groups. Postoperative Knee Society Function Score (KS-FS) was significantly higher in the HKA in-range group than the outlier group (p = 0.01). The Knee Society Knee Score and all subscales of the Knee injury Osteoarthritis Outcome Score were comparable between the groups. A multivariate analysis revealed a significant association between age at operation and postoperative KS-FS > of 80 points. Neither HKA in-range nor JLOA in-range were associated with the higher knee function. In conclusion, TKA-postoperative inclination of the joint line was not relevant to the short-term PROs. Treatment strategies that attempt to make joint line inclination in order to improve postoperative PROs should be avoided, and alignment goals such as kinematic alignment should be considered carefully.

Lateral shift of the femoral condyle after total knee arthroplasty: simulation using 2D-templates of the medial pivot design on knee radiographs of young Japanese patients

Background

Total knee arthroplasty (TKA) is an established surgical treatment for advanced knee osteoarthritis by which patients can expect improvement of knee pain and function. Although many surgeons have investigated limb alignment after TKA, changes in coronal positional relation between the femur and tibia are not known well.

Methods

Radiographs of 105 knees of young Japanese patients between 20 and 49 years-old (60 men and 45 women) without osteoarthritic changes who received arthroscopic surgeries at our hospital were used in this study. Using 2D-templates of the medial pivot design (the FINE total knee), we simulated TKA on a SYNAPSE-PACS software. First, the femoral component was placed in normal knee alignment and then was merged to the medial concave of the insert where the tibial component was placed in neutral alignment. The length of the mediolateral shift of the femoral component was measured as an estimate of lateral shift of the femoral condyle, of which association with radiographic parameters including the femorotibial angle (FTA), lateral distal femoral angle (LDFA), and medial proximal tibial angle (MPTA) was analyzed. Subjects were classified into three groups according to the femoral component size that was chosen in simulation of TKA, and the lateral shift of the femoral condyle was compared between groups.

Results

The estimated mean lateral shift of the femoral condyle was 5.99 ± 1.98 mm and was greater in males than females (p < 0.05). Also, it was most highly correlated with the medial proximal tibial angle (MPTA) (r = − 0.553, p < 0.01). A group receiving larger component sizes significantly shifted more laterally compared with a group receiving smaller component sizes (p < 0.01).

Conclusions

These results suggest that the coronal positional relation between the femur and tibia is altered and subsequent ligament imbalance may occur after mechanically aligned TKA using the medial pivot design.

Seven phenotypes of varus osteoarthritic knees can be identified in the coronal plane

PURPOSE

Recommendations for resecting distal femur and proximal tibia in mechanical and anatomical alignment techniques are standardized. Kinematic alignment propagates individualizing resection planes. Whether significant variation exists, to warrant departure from standardized resection planes, has not been shown thus far in a large cohort of knees and with a wide range of varus deformity. The null hypothesis of this study was that there was no phenotypic variation in varus osteoarthritic knees. The aim of this paper was to determine whether distinct phenotypes could be identified, based on variations in coronal femoral and tibial morphology, which could aid in surgical planning and categorizing varus knees for future studies.

METHODS

2129 full-leg weightbearing radiographs were analyzed (1704 preoperative; 425 of contralateral arthritic knee). Measurements made were of HKA (hip-knee-ankle angle), VCA (valgus correction angle), mLDFA (lateral mechanical distal femoral angle), aLDFA (lateral anatomical distal femoral angle), MPTA (medial proximal tibial angle), MNSA (medial neck shaft angle), TAMA (angle between tibial mechanical and anatomical axes), and TPDR (percentage length of tibia proximal to extra-articular deformity).

RESULTS

Seven distinct types were identified covering 2021 knees, reducible to 4 broad phenotypes: 11% were Type 1 'Neutral' knees showing values close to reported normal knees (mean VCA 5.5°, mLDFA 87°, aLDFA 81°). 38% were Type 2 'Intra-articular varus' with medial intra-articular bone loss (mean mLDFA 90.9°, MPTA 85.4°, VCA of 5.7°). 41% were Type 3 'Extra-articular varus' with extra-articular deformity (EAD). Type 3a had proximal tibial EAD; Type 3b had tibial diaphyseal EAD; Type 3c had femoral EAD (mean VCA 8.7°, HKA 166°), and severe medial bone loss (mean mLDFA 92°, MPTA 83°). 9% were Type 4 'Valgoid type' with features of valgus knees: Type 4a had medial femoral bowing (mean VCA 2.9°); Type 4b had significant distal femoral valgus (mean mLDFA 85.3°, aLDFA 78.6°).

CONCLUSIONS

The null hypothesis that there was no phenotypic variation in varus osteoarthritic knees was rejected as considerable variation was found in coronal morphology of femur and tibia. Four broad phenotypic groups could be identified. Plane of the knee joint articular surface was quite variable. This has relevance to planning and performance of corrective osteotomies, unicompartmental and total knee arthroplasty.

LEVEL OF EVIDENCE

III, retrospective cohort study.

Medial Opening Wedge Proximal Tibial Osteotomy: Lessons Learned from a Series of 175 Consecutive Cases

INTRODUCTION

High tibial osteotomy (HTO) is a surgical procedure aimed at inhibiting the progression of osteoarthritis of the knee joint. The aim of this study was to identify factors influencing the functional outcome after opening wedge valgus HTO.

METHODS

A total of 175 cases (155 patients) of varus-correcting high tibial open-wedge osteotomies using the Tomofix plate were reviewed retrospectively. Patients answered the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire and 4 survey follow-up questions.

RESULTS AND DISCUSSION

A total of 76 of the 155 patients studied (84 of the 175 knees) completed the KOOS questionnaire, on average 3.1 years (SD 1.8 years) after the surgery. The median scores (with median absolute deviations [MAD]) for the KOOS pain, symptoms, daily activities, sports, and quality of life sections were, respectively, 76.4 (MAD 12.5), 75.0 (MAD 14.3), 85.3 (MAD 11.8), 50.0 (MAD 25.0), and 59.4 (MAD 21.9). No cases of nonunion were observed throughout the length of the study. Identified predictors of worse outcomes were higher weight and body mass index, limited knee flexion, genu varum and tibial varus of small magnitude, active smoking status at the time of surgery, further surgery for plate removal, and some grades of chondropathy in the patellofemoral, medial tibial, and femoral compartments. Patient gender, joint obliquity and over- or undercorrection were not associated with any of the outcomes.

CONCLUSION

This study shows good results following valgus HTO that are comparable to outcomes following total knee arthroplasty, reinforcing the option of HTO as a valid alternative for total knee arthroplasty.

The Impact of Psychological Factors and Their Treatment on the Results of Total Knee Arthroplasty

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There is a growing body of evidence implicating psychosocial factors, including anxiety, depression, kinesiophobia, central sensitization, and pain catastrophizing, as negative prognostic factors following total knee arthroplasty (TKA).

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Symptoms of anxiety and depression likely represent risk factors for negative outcomes in patients undergoing TKA. However, few studies have assessed the impact of preoperative interventions for these conditions on postoperative outcomes.

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The Tampa Scale of Kinesiophobia and the Central Sensitization Inventory have demonstrated value in the diagnosis of kinesiophobia and central sensitization. Higher preoperative indices of kinesiophobia and central sensitization predict worse patient-reported outcomes postoperatively.

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Although evidence is limited, cognitive-behavioral therapy for kinesiophobia and duloxetine for central sensitization may help to diminish the negative impact of these preoperative comorbidities. It is important to note, however, that outside the realm of TKA, cognitive-behavioral therapy has been recognized as a more effective treatment for central sensitization than medical treatment.

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Awareness of these issues will allow surgeons to better prepare patients regarding postoperative expectations in the setting of a comorbid psychosocial risk factor. Further research into the role of preoperative assessment and possible treatment of these conditions in patients undergoing TKA is warranted.

The Impact of Race and Socioeconomic Status on Total Joint Arthroplasty Care

BACKGROUND

Racial minorities and patients from lower socioeconomic backgrounds are less likely to undergo total joint arthroplasty (TJA) for degenerative joint disease (DJD). However, when these patients do present for care, little is known about the overall severity of DJD and surgical wait times.

METHODS

A retrospective cohort of 407 patients (131 black and 276 white) who presented to an arthroplasty clinic and went on to receive TJA was established. Severity of osteoarthritis was assessed radiographically via Kellgren-Lawrence (KL) grade. Preoperative Knee Society Score (KSS) and Harris Hip Score (HHS) were used to measure joint pain and function. Multivariate regression modeling and analysis of covariance were used to examine racial and socioeconomic differences in KL grade, KSS, HHS, and time to surgery.

RESULTS

Black patients presented with significantly greater KL scores than white patients (P = .046, odds ratio = 1.65, 95% confidence interval [1.01, 2.70]). In contrast, there were no statistically significant racial differences in the mean preoperative KSS (P = .61) or HHS (P = .69). Black patients were also found to wait, on average, 35% longer for TJA (P = .03, hazard ratio = 1.35, 95% confidence interval [1.04, 1.75]). Low income was associated with higher KL grade (P = .002), lower KSS (P = .07), and lower HHS (P = .001).

CONCLUSION

Despite presenting with more advanced osteoarthritis, black patients reported similar levels of joint dysfunction and had longer surgical wait times when compared with white patients. Lower socioeconomic status was similarly associated with more severe DJD.