Abstract
Background
Total knee replacement (TKR) is clinically and cost-effective. The surgical approach employed influences the outcome, however there is little generalisable and robust evidence to guide practice.
Methods
875,166 primary TKRs captured in the National Joint Registry, linked to hospital
inpatient, mortality and patient reported outcome measures (PROMs) data, with up to 15.75 years follow-up were analysed. There were 10 surgical approach groups: medial parapatellar, midvastus, subvastus, lateral parapatellar, ‘other’ and their minimally invasive versions. Survival methods were used to compare revision rates and 45-day mortality. Groups were compared using Cox proportional hazards regression and Flexible Parametric Survival Modelling (FPM). Confounders included age at surgery, sex, risk group, American Society of Anesthesiologists grade, TKR fixation, year of primary, body mass index, and for mortality, deprivation and Charlson comorbidity subgroups. PROMs were analysed with regression modelling or non-parametric methods.
Results
The conventional midvastus approach was associated with lower revision rates
(Hazard Rate Ratio (HRR) 0.80 (95% CI 0.71-0.91) P=0.001) and the lateral
parapatellar with higher revision rates (HRR 1.35 (95% CI 1.12-1.63) P=0.002)
compared to the conventional medial parapatellar approach. Mortality rates were
similar between approaches. PROMs showed statistically significant, but not clinically important, differences.
Conclusions
There is little difference in PROMs between the various surgical approaches in TKR
with all resulting in good outcomes. However, the conventional midvastus approach (used in 3% of cases) was associated with a 20% reduced risk of revision surgery compared to the most commonly used knee approach (the medial parapatellar: used in 91.9% of cases).
Total knee replacement (TKR) is clinically and cost-effective. The surgical approach employed influences the outcome, however there is little generalisable and robust evidence to guide practice.
Methods
875,166 primary TKRs captured in the National Joint Registry, linked to hospital
inpatient, mortality and patient reported outcome measures (PROMs) data, with up to 15.75 years follow-up were analysed. There were 10 surgical approach groups: medial parapatellar, midvastus, subvastus, lateral parapatellar, ‘other’ and their minimally invasive versions. Survival methods were used to compare revision rates and 45-day mortality. Groups were compared using Cox proportional hazards regression and Flexible Parametric Survival Modelling (FPM). Confounders included age at surgery, sex, risk group, American Society of Anesthesiologists grade, TKR fixation, year of primary, body mass index, and for mortality, deprivation and Charlson comorbidity subgroups. PROMs were analysed with regression modelling or non-parametric methods.
Results
The conventional midvastus approach was associated with lower revision rates
(Hazard Rate Ratio (HRR) 0.80 (95% CI 0.71-0.91) P=0.001) and the lateral
parapatellar with higher revision rates (HRR 1.35 (95% CI 1.12-1.63) P=0.002)
compared to the conventional medial parapatellar approach. Mortality rates were
similar between approaches. PROMs showed statistically significant, but not clinically important, differences.
Conclusions
There is little difference in PROMs between the various surgical approaches in TKR
with all resulting in good outcomes. However, the conventional midvastus approach (used in 3% of cases) was associated with a 20% reduced risk of revision surgery compared to the most commonly used knee approach (the medial parapatellar: used in 91.9% of cases).
| Original language | English |
|---|---|
| Pages (from-to) | 144-157 |
| Number of pages | 14 |
| Journal | Knee |
| Volume | 31 |
| Early online date | 25 Jun 2021 |
| DOIs | |
| Publication status | Published - 1 Aug 2021 |
Bibliographical note
Funding Information:AWB is principal investigator on a grant funded by Stryker investigating the outcome of a total knee replacement manufactured by Stryker. GSM has received financial support for other research work from Arthritis Research UK, The Orthopaedics Trust, The Royal College of Surgeons of England, and The Royal Orthopaedic Hospital Hip Research and Education Charitable Fund. GSM has also received personal fees for undertaking medicolegal work for Leigh Day. MRR has received grant funding or lecture fees from the Health Foundation, Stryker, Zimmer Biomet, Heraeus Medical, 3M Healthcare, Vifor Pharma, Schuelke, Curetis, and Salus. MRW is a co-applicant on a grant funded by Stryker investigating the outcome of a total knee replacement manufactured by Stryker.
Funding Information:
This study was supported by funding from Healthcare Quality Improvement Partnership and the National Joint Registry. Posts of authors of this work are part funded by a grant from the National Joint Registry to conduct statistical analysis for the National Joint Registry.
Funding Information:
This study was also supported by the NIHR Biomedical Research Centre at University Hospitals Bristol NHS Foundation Trust and the University of Bristol. The views expressed in this publication are those of the author(s) and not necessarily those of the NHS, the National Institute for Health Research or the Department of Health and Social Care.
Publisher Copyright:
© 2021 Elsevier B.V.
Keywords
- knee replacement
- surgical approach
- outcomes
- revisions surgery
- mortality