Gardening/yardwork in people with knee osteoarthritis is not associated with symptom or structural progression over 48 months: data from the Osteoarthritis Initiative

To evaluate the relationship of gardening/yardwork with symptomatic and structural progression in those with pre-existing radiographic knee osteoarthritis (OA) in the Osteoarthritis Initiative (OAI), an observational study designed to evaluate potential and known biomarkers and risk factors of knee OA.

We conducted a cohort study nested within the OAI, including participants ≥ 50 years old with radiographic OA in at least one knee at the time of OAI enrollment. A participant reported the level of gardening/yardwork activity in a self-administered survey. Logistic regression analyses were used to evaluate the association of gardening/yardwork on new frequent knee pain, Kellgren-Lawrence (KL) worsening, medial joint space narrowing (JSN) worsening, and improved frequent knee pain.

Of 1808 knees (1203 participants), over 60% of knees had KL grade = 2, 65% had medial JSN, and slightly more than a third had frequent knee symptoms. Gardeners/yardworkers and non-gardners/yardworkers had similar “worsening” outcomes for new knee pain (29% vs. 29%), KL worsening (19% vs. 18%), and medial JSN (23% vs. 24%). The adjusted odds ratio (OR) for the “worsening” outcomes of new knee pain, KL worsening, and medial JSN worsening were 1.0 (0.7–1.3), 1.0 (0.8–1.3), and 1.1 (0.9–1.4), respectively. The gardeners/yardworkers had an adjusted OR of 1.2 (0.9–1.7) for improved knee pain compared with non-gardners/yardworkers.

Gardening/yardwork is not associated with knee OA progression and should not be discouraged in those with knee OA.