# Effect of component alignment on soft tissue conditions during total knee replacement

> **NIH NIH P20** · CLEMSON UNIVERSITY · 2021 · $239,481

## Abstract

SUMMARY
While total knee replacement (TKR) is regarded as a reasonably successful procedure in terms of revision
rates (95% survivorship at 10 years), about 25% of patients remain dissatisfied with the outcome of their
surgery. Moreover, nearly half of early TKR revisions are considered preventable if surgical techniques could
reliably provide for proper component alignment and ligament balance. Considering that the number of TKR in
the USA is projected to exceed 4.3 million annually by 2030, this equates to millions of dissatisfied patients
with unsatisfactory clinical outcomes. It is well-established that stable TKR function is critical for successful
patient outcomes. During TKR surgery, surgeons perform manual evaluations to detect joint instability and
proceed to correct it by adjusting the TKR alignment and balancing the tension in the soft tissues surrounding
the joint. Unfortunately, there is little evidence to guide surgeons in determining when alignment and soft tissue
tension are adequate. It has long been speculated that soft tissue tension profiles could be a predictor of TKR
clinical outcome compared to component alignment. Based on our published clinical studies, it is our scientific
premise that alignment impacts soft tissue tension and the stability perceived by the patients, contributing to poor
clinical scores. However, adequate methods for measuring soft tissue tension in vivo do not exist and the internal
mechanical environment in the knee after TKR is poorly defined. Our long-term goal is to develop a validated
finite element (FE) model of TKR and use it to determine the tension profiles of nine individual soft tissue
structures crossing the knee joint and to establish quantitative relationships between component alignment, soft
tissue tension, and clinical outcome in TKR patients. We hypothesize that i) component alignment affects soft
tissue tension conditions during TKR; and ii) these soft tissue conditions are significant predictors of clinical
outcomes after TKR. We propose to address these knowledge and technical gaps using a unique experimental
and computational modeling approach. We identify the following specific aims: 1) adapt a finite element model of
the natural knee to evaluate soft tissue tension in TKR; 2) determine the effect of TKR alignment on soft tissue
tension; and 3) determine the effect of tension profiles on in vivo clinical outcomes of TKR. Successful
completion of this proposal will: i) demonstrate the practical use of intra-operative measurements of knee
kinematics during passive range of motion (ROM) for determining soft-tension profiles in FE TKR models and; ii)
identify potential predictors of poor functional outcomes related to component alignment and soft tissue tension;
and iii) identify potential detectable events that could inform technology innovation for more meaningful use of
intra-operative sensing of soft tissue tension and knee motions. This project will inform our future R01 proposal...

## Key facts

- **NIH application ID:** 10244922
- **Project number:** 5P20GM121342-04
- **Recipient organization:** CLEMSON UNIVERSITY
- **Principal Investigator:** Melinda Harman
- **Activity code:** P20 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $239,481
- **Award type:** 5
- **Project period:** 2018-09-15 → 2023-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10244922

## Citation

> US National Institutes of Health, RePORTER application 10244922, Effect of component alignment on soft tissue conditions during total knee replacement (5P20GM121342-04). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10244922. Licensed CC0.

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