Patient-reported knee symptoms associated with underlying cartilage damage

Published results showed a strong association between patient-reported knee symptoms and the burden and severity of underlying cartilage damage rather than with specific meniscal pathology.

Elizabeth G. Matzkin, MD, and colleagues used the KOOS questionnaire to collect patient-reported knee symptoms among 565 patients who underwent knee arthroscopy from 2012 to 2019. Researchers intraoperatively confirmed and classified the diagnosis of meniscal pathology and concomitant cartilage damage. Multivariable regression models that adjusted for possible confounders were used to examine the association of specific pathological conditions of the knee with the presence of preoperative patient-reported knee symptoms.

The mean average symptom score of the patients was 2.1, with more frequent catching/locking symptoms reported among 62.7% of patients, more frequent grinding/clicking/popping symptoms reported among 74.3% and worse pain when pivoting reported among 85.3% of patients. Researchers found worse pain when pivoting was more likely to be reported by patients older than 40 years of age vs. patients 40 years of age or younger. A higher mean average symptom score was found for women, who also had more frequent grinding/clicking/popping symptoms compared with men.

Elizabeth G. Matzkin

Although researchers found no significant association between meniscal tear pattern and patient-reported knee symptom scores, the mean average symptom score increased with the severity of cartilage damage as defined by the Outerbridge grade. Results showed the burden of cartilage damage, as defined by the number of compartments involved, also increased the mean average symptom score from 1.9 for patients with no compartment involvement to 2.4 for patients with tricompartmental damage.

Female sex, a BMI of 25 kg/m² or greater, smoking and tricompartmental cartilage damage were significant predictors of a higher mean average symptom score, according to results of multivariable linear regression models. Researchers found significant associations between tricompartmental involvement and a higher frequency of catching/locking symptoms, female sex and a higher frequency of grinding/clicking/popping symptoms and a BMI of 25 kg/m² or greater and worse pain when pivoting.

“Meniscal tears and cartilage damage often coexist in patients with symptomatic knee pain. This study demonstrates that patient-reported knee symptoms, traditionally defined as ‘meniscal’ or ‘mechanical’ symptoms, are likely associated with underlying cartilage damage rather than meniscal pathology,” Matzkin told Healio Orthopedics. “It will be important moving forward to specifically describe preoperative patient-reported knee symptoms in order to study and more accurately understand outcomes after knee arthroscopy.”