Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.


The Relationship between Varus and Valgus Thrust and Meniscal Damage in Persons with Knee Osteoarthritis.

Chang4,  Alison H., Guermazi1,  Ali, Roemer1,  Frank, Moisio5,  Kirsten, Song5,  Jing, Dunlop4,  Dorothy D., Nevitt6,  Michael C.

Boston University
Northwestern University, LaGrange, IL
Northwestern University, Downers Grove, IL
Northwestern University, Chicago, IL
Northwestern University
UCSF, San Francisco, CA
UCSF

Purpose:

Varus thrust observed during gait has been shown to be associated with a 4-fold increase in the risk of medial knee osteoarthritis (OA) progression. It is plausible that a varus thrust may trigger or exacerbate medial meniscal damage as a cumulative effect of the acute increase in medial load with each step of walking. A parallel relationship may exist between valgus thrust and the lateral meniscus. We tested the hypotheses: 1) varus thrust is associated with medial meniscal damage (tear, maceration, extrusion); and 2) valgus thrust is associated with lateral meniscal damage.

Methods:

The sample included Osteoarthritis Initiative (OAI) participants with symptomatic radiographic knee OA (data from public release data sets version 0.2.2 and 1.2.1 and from an NIH-funded ancillary study). Trained examiners assessed all participants at the 12-month visit for varus and valgus thrust presence by gait observation. The following sequences from the OAI protocol were used for meniscal assessment: sagittal IW 2D TSE FS, sagittal 3D DESS WE, axial MPR of SAG 3D DESS WE, coronal MPR of SAG 3D DESS WE. Meniscal status was scored according to the BLOKS system in the anterior, body and posterior horn of the medial and lateral meniscus. In addition, extrusion was scored from 0–3, with presence defined as > 0. We used logistic regression to specifically evaluate the relationship of varus thrust to medial meniscal damage (tear, maceration, and extrusion) and valgus thrust to lateral meniscal damage, adjusting for age, gender, and BMI.

Results:

496 persons (1 knee/person) (mean age 62 years, BMI 30, 58% women) were examined. Varus thrust was present in 169 knees (34%) and valgus thrust in 31 knees (6%). As shown in Table 1, varus thrust was significantly associated with medial meniscal tear and with medial meniscal maceration.

Neither varus thrust nor valgus thrust was significantly associated with meniscal extrusion (not shown).

Conclusion:

Varus thrust during ambulation was associated with medial meniscal tear and maceration, but not with extrusion, with similar findings for valgus thrust and lateral meniscal damage. Longitudinal studies may help elucidate the cause-effect relationship between these factors and how they might act in concert to accelerate OA progression.

Table 1. Varus Thrust and Medial Meniscal Damage

Thrust Status (n = 496 knees)Number of Knees (row %) with Medial Meniscal Tear (238 knees, 48.0%)Medial Meniscal Tear Adjusted OR (95% CI)Number of Knees (row %) with Medial Meniscal Maceration (172 knees, 34.7%)Medial Meniscal Maceration Adjusted OR (95% CI)
No varus thrust (reference) (n = 327 knees)142 (43.4%)Reference99 (30.3%)Reference
Varus thrust (n = 169 knees)96 (56.8%)1.50 (1.01, 2.22)73 (43.2%)1.53 (1.02, 2.29)

As shown in Table 2, valgus thrust was significantly associated with lateral meniscal maceration; the association with lateral meniscal tear approached significance.

Table 2. Valgus Thrust and Lateral Meniscal Damage

Thrust Status (n = 496 knees)Number of Knees (row %) with Lateral Meniscal Tear (121 knees, 24.4%)Lateral Meniscal Tear Adjusted OR (95% CI)Number of Knees (row %) with Lateral Meniscal Maceration (77 knees, 15.5%)Lateral Meniscal Maceration Adjusted OR (95% CI)
No valgus thrust (reference) (n = 465 knees)109 (23.4%)Reference68 (14.6%)Reference
Valgus thrust (n = 31 knees)12 (38.7%)2.12 (0.98, 4.56)9 (29.0%)2.38 (1.04, 5.45)

To cite this abstract, please use the following information:
Chang, Alison H., Guermazi, Ali, Roemer, Frank, Moisio, Kirsten, Song, Jing, Dunlop, Dorothy D., et al; The Relationship between Varus and Valgus Thrust and Meniscal Damage in Persons with Knee Osteoarthritis. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :202
DOI: 10.1002/art.27971

Abstract Supplement

Meeting Menu

2010 ACR/ARHP