Abstract
Clinical laxity tests are used for assessing knee ligament injuries and for soft tissue balancing in total knee arthroplasty. This study reports the development and validation of a quantitative technique of assessing collateral knee laxity
through accurate measurement of potential variables during routine clinical
examination. The hypothesis was that standardisation of a clinical stress test
would result in a repeatable range of laxity measurements.Non- invasive
infrared tracking technology with kinematic registration of joint centres gave
real-time measurement of both coronal and sagittal mechanical tibiofemoral
alignment. Knee flexion, moment arm and magnitude of the applied force were all measured and standardised. Three clinicians then performed six knee laxity
examinations on a single volunteer using a target moment of 18Nm. Standardised laxity measurements had small standard deviations (within 1.1°) for each clinician and similar mean values between clinicians, with the valgus laxity
assessment (mean of 3°) being slightly more consistent than varus (means of 4°
or 5°).The manual technique of coronal knee laxity assessment was successfully
quantified and standardised, leading to a narrow range of measurements (within
the accuracy of the measurement system). Minimising the subjective variables of
clinical examination could improve current knowledge of soft tissue knee
behaviour.
through accurate measurement of potential variables during routine clinical
examination. The hypothesis was that standardisation of a clinical stress test
would result in a repeatable range of laxity measurements.Non- invasive
infrared tracking technology with kinematic registration of joint centres gave
real-time measurement of both coronal and sagittal mechanical tibiofemoral
alignment. Knee flexion, moment arm and magnitude of the applied force were all measured and standardised. Three clinicians then performed six knee laxity
examinations on a single volunteer using a target moment of 18Nm. Standardised laxity measurements had small standard deviations (within 1.1°) for each clinician and similar mean values between clinicians, with the valgus laxity
assessment (mean of 3°) being slightly more consistent than varus (means of 4°
or 5°).The manual technique of coronal knee laxity assessment was successfully
quantified and standardised, leading to a narrow range of measurements (within
the accuracy of the measurement system). Minimising the subjective variables of
clinical examination could improve current knowledge of soft tissue knee
behaviour.
| Original language | English |
|---|---|
| Pages (from-to) | 699-708 |
| Number of pages | 10 |
| Journal | Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine |
| Volume | 226 |
| Issue number | 9 |
| Early online date | 3 Jul 2012 |
| DOIs | |
| Publication status | Published - 1 Sep 2012 |
Keywords
- clinical assessment
- knee laxity
- ligament injuries
- non-invasive assessment
- total knee arthroplasty