{'fraction_non_alphanumeric': 0.047725577926920205, 'fraction_numerical': 0.03206562266964952, 'mean_word_length': 4.181467181467181, 'pattern_counts': {'":': 0, '<': 1, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 1, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Rate of knee cartilage loss after partial meniscectomy.

OBJECTIVE
Surgical removal of the meniscus of the knee is thought to be a risk factor for later appearance of knee osteoarthritis (OA). We examined whether there is a difference in cartilage loss in those who undergo a partial meniscectomy compared to healthy controls.


METHODS
Eight patients who underwent a meniscectomy (5 partial medial, 3 partial lateral) and 13 controls with normal knee radiographs and magnetic resonance imaging (MRI) had an MRI at baseline and at a mean 28.6 +/- 7.6 months followup. Articular cartilage volumes were determined by processing images acquired in the sagittal plane using T1 weighted fat saturation MRI on an independent work station.


RESULTS
The mean +/- SD of percentage rates of cartilage loss from baseline volume were 4.1 +/- 2.8% per year for the meniscectomy subjects and -2.3 +/- 3.0% per year for the controls (difference 6.5% per year, 95% CI 3.7-9.3% per year; p < 0.001). After adjustment for age, body mass index, and sex the difference increased slightly to 6.9% per year (95% CI 3.4-10.3%; p = 0.001).


CONCLUSION
This study suggests that significant rates of cartilage loss are seen in subjects post partial meniscectomy compared with healthy controls. This may be a useful model in which to examine therapies to prevent OA.