Understanding the difference between symptoms of focal cartilage defects and osteoarthritis of the knee: a matched cohort analysis

Purpose

Comparing symptoms of patients with focal cartilage defects of the knee to those with knee osteoarthritis.

Methods

Prospectively maintained databases identified patients with focal cartilage defects (FCD group) who underwent osteochondral allograft transplantation and patients with osteoarthritis (OA group) undergoing arthroplasty. Patients between 18 and 55 years of age were included and matched based on age. Baseline patient demographics, symptoms, and patient-reported outcomes including the Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR), SF-12, and VR-12 questionnaires were recorded. Patient symptoms and individual responses of the KOOS JR were compared between groups. Regression analysis was used to evaluate the association between pre-operative factors that significantly differed between groups and the KOOS JR questionnaire.

Results

Sixty-four patients were included: 32 patients in each group. The FCD group had a significantly lower body mass index (BMI) (p = 0.04) and greater number of workers’ compensation cases (p = 0.027) when compared to the OA group. Patients in the OA group complained more frequently of medial-sided pain (p = 0.02) and knee swelling (p = 0.003). The OA cohort also had greater pain with fully straightening the knee (p = 0.012), pain with standing upright (p = 0.016), and pain with rising from sitting (p = 0.003). Patients in the FCD group had greater KOOS JR outcome scores (51.5 ± 12.9 vs. 41.5 ± 20.5; p = 0.023).

Conclusion

When compared to patients with focal cartilage defects, adults with knee osteoarthritis scheduled for knee arthroplasty have a more severe presentation of symptoms, particularly medial-sided pain, swelling of the knee, pain associated with straightening the knee, standing upright, and rising from sitting.