The effect of knee joint loading and immobilization on the femoral cartilage thickness in paraplegics.

BACKGROUND

Femoral cartilage thickness has been used as an indicator for immobilization and unloading in patients with spinal cord injury (SCI). However, conflicting results have been reported on this subject.

OBJECTIVES

(i) To determine femoral cartilage thickness alterations after prolonged immobilization, (ii) to demonstrate the effect of the daily standing or ambulation time on the cartilage and (iii) to analyze the predictors of the femoral cartilage in patients with SCI.

METHODS

A total of 50 patients with SCI and 50 healthy age and sex-matched volunteers were enrolled in the study. A physician scanned both knees of all participants and measurements were taken at three locations: trochlear notch, midpoints of the medial and lateral condyle.

RESULTS

The trochlear notch, medial and lateral condyle femoral cartilage thickness of both sides were significantly thicker in the control group (P<0.05). Patients with <1 h daily standing/walking time had higher thickness measurements in all sub parameters than patients with >1 h daily standing/walking time (P<0.05). Daily standing/walking time and the Walking index for SCI score were statistically significant predictors for cartilage thickness.

CONCLUSION

SCI patients had thinner knee cartilage compared with healthy individuals in ultrasonographic assessment. More than 1 h daily standing/walking time may have a negative effect on the femoral cartilage thickness. Thus, ultrasonographic evaluation of the femoral cartilage should be considered in clinical practice to detect early cartilage thinning in patients with SCI.