Disclosures Altered Kinematics in the ACL Reconstructed Knee as a - - PowerPoint PPT Presentation

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Altered Kinematics in the ACL Reconstructed Knee as a Mechanism of Early Onset Osteoarthritis

Musa Zaid1 BS, Drew Lansdown1 MD, Valentina Pedoia2 PhD, Favian Su2 BS, Lauren Tufts2 BS, Subburaj Karupppasamy2 PhD, Lauren Tufts2 BS, Brian Feeley1 MD, Richard Souza1 PhD, Xiaojuan Li2 PhD, C. Benjamin Ma1 MD

• 1. UCSF Department of Orthopaedic Surgery.
• 2. UCSF Department of Radiology and Biomedical Imaging.

University of California, San Francisco

Disclosures

• Zaid, Lansdown, Wu, Hoppe, Karupppasamy, Tufts,

Feeley, Souza, Li:

– No Disclosures

• Ma:

– Educational support from Zimmer – Research support from Zimmer, Histogenics, Moximed

• Study Funding:

– UCSF CTSI – AOSSM Genzyme Osteoarthritis Grant for Clinical Research – NIH/NIAMS P50 AR060752

Introduction

• ACL provides anterior-posterior and rotational stability

to the knee.

• ACL injury leads to osteoarthritis.

– 50% of patients develop OA 10-15 years following ACL rupture1.

• Kinematics shown to be altered following ACL injury

and reconstruction2.

• No previous studies have demonstrated the longitudinal

relationship between kinematics and cartilage health.

Introduction Purpose & Hypothesis Methods Results Discussion

1.Miyasaka K, Daniel D, Stone M, Hirshman P. Am J Knee Surg 1991. 2.Lohmander LS, Ostenberg A, Englund M, Roos H. Arthritis Rheum. 2004.

Purpose and Hypothesis

• Purpose:

– To investigate the longitudinal interrelationship between lower extremity kinematics and cartilage health following ACL injury and reconstruction.

• Hypothesis:

– Altered lower extremity kinematics in the ACL reconstructed knee will lead to faster cartilage degeneration.

Introduction Purpose & Hypothesis Methods Results Discussion

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Methods

• Subjects:
• Exclusion Criteria:

– Other ligamentous injuries, meniscal injury requiring repair, previous history of arthritis, knee trauma, or surgery.

Introduction Purpose & Hypothesis Methods Results Discussion

N=20 Average Age 29 +/- 8.9 years Average BMI 23.2 +/- 3.1 kg/m2 Gender 10 males, 10 females

ACL Rupture 6 Month MRI ACL Reconstruction Baseline MRI 1 Year MRI

Methods

Introduction Purpose & Hypothesis Methods Results Discussion

• 3. Carpenter R, Majumdar S, Ma C. Arthroscopy 2009
• Kinematic MRI:

– Use MRI to determine 3-dimensional knee kinematics3. – Sagittal T2 FSE images obtained in extension and knee flexion loaded with 25% of total body weight. – Customized in house software used to determine tibial and femoral axis3. – Determine position of tibia relative to femur in the extended and flexed states.

Methods

Introduction Purpose & Hypothesis Methods Results Discussion

• 4. Li X, Ma C, Link T, et al. Osteoarthritis and Cartilage. 2007
• Cartilage T1p MRI:

– Quantifies proteoglycan content4. – Detection

• f

early cartilage damage4. – Comprehensive quantification

• f

cartilage T1p relaxation times of the medial and lateral femoral condyles and tibial cartilage was measured with customized software. – Cartilage was divided into subcompartments to examine regional variations in cartilage damage.

5 10 15 20 25 Baseline 1 Year Avg Ipsi Extended Tibial Position Avg Contra Extended Tibial Position

Average Tibial Position in Knee Extension

Introduction Purpose & Hypothesis Methods Results Discussion Anterior Posterior

* *

* Indicates p < 0.05

Tibial position is shifted more anterior relative to the femur in the extended state at baseline.

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5 10 15 20 25 Baseline 1 Year Avg Ipsi Flexed Tibial Position Avg Contra Flexed Tibial Position

Average Tibial Position in Knee Flexion

Introduction Purpose & Hypothesis Methods Results Discussion

* *

* Indicates p < 0.05

Tibial position is shifted more anterior relative to the femur in the flexed state at baseline.

Anterior Posterior

Side to Side Difference in Extended Tibial Position vs Progression of T1p in LFC from Baseline to 1 Year

Introduction Purpose & Hypothesis Methods Results Discussion

The side to side difference in the extended tibial position correlates to the progression of cartilage T1p in the lateral femoral condyle.

• 6
• 4
• 2

2 4 6 8

• 3
• 2
• 1

1 2 3 4 Progression of T1p in the LFC from Baseline to 1 Year SSD in Tibial Position in the Extended State at 1 Year

Spearman’s Rho = 0.44 p = 0.046

Side to Side Difference in Flexed Tibial Position vs Progression of T1p in pLT from Baseline to 1 Year

Introduction Purpose & Hypothesis Methods Results Discussion

The side to side difference in the flexed tibial position correlates to the progression of cartilage T1p in the posterior lateral tibia from baseline to 1 year.

• 15
• 10
• 5

5 10 15

• 6
• 4
• 2

2 4 Progression of T1p in the Posterior LT from Baseline to 1 Year SSD in the Flexed Tibial Position at 1 Year

Spearman’s Rho = 0.444 P = 0.044

Discussion

• Knee kinematic are altered following ACL injury.

– Tibia more anterior in extended and flexed states at baseline. – Normalization of kinematics 1 year post reconstruction.

• Alterations in knee kinematics are related to detectable

cartilage degeneration in the knee as soon as 1 year following ACL reconstruction.

• Longitudinal relationship between kinematics and the

progression of cartilage damage.

– Alterations in knee kinematics at 1 year post reconstruction are correlated to the progression of T1p from baseline to 1 year. Introduction Purpose & Hypothesis Methods Results Discussion

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Discussion

• Haughom et al has demonstrated a relationship between

altered knee kinematics and cartilage damage4.

• Our study is unique as it follows patients longitudinally to

assess how altered kinematics relate to cartilage damage

• ver time.
• Understanding the longitudinal interrelationship between

the kinematics in the ACL reconstructed knee and signs of early cartilage change may provide insight into the development and prevention of post-traumatic

• steoarthritis.
• Will continue longitudinal follow up at 2 and 3 years.

Introduction Purpose & Hypothesis Methods Results Discussion

• 4. . Haughom B, et al, The Knee, August 2012, 482-487

Acknowledgements

• C. Benjamin Ma, MD
• Xiaojuan Li, PhD
• Brian Feeley, MD
• Richard Souza, PT PhD
• Sharmila Majumdar, PhD
• Christina Allen, MD
• Drew Lansdown, MD
• Valentina Pedoia, PhD
• Favian Su, BS
• Lauren Tufts, BS
• Subburaj Karupppusamy, PhD
• UCSF Department of Orthopaedic Surgery
• Musculoskeletal Quantitative Imaging Group
• UCSF Department of Radiology
• The CTRFP Team

Funding:

• AOSSM Genzyme Osteoarthritis Grant for Clinical Research
• NIH/NIAMS P50 AR060752
• CTSI/UCSF Clinical and Translational Research Fellowship