Table 1 Exclusion criteria

Significant co-morbid disease that would threaten safety or impair ability to participate in interventions or testing, previous acute knee injury, bilateral severe tibiofemoral OA, severe patellofemoral OA (JSN = 3 using OARSI atlas), no definite medial tibiofemoral OA, severe obesity, low weight.

Symptomatic or severe coronary artery disease; severe HTN; active cancer other than skin cancer; anemia; dementia; liver disease; COPD; peripheral vascular disease; inability to walk without an assistive device; blindness; type 1 diabetes; type 2 diabetes on thiazolidinedione agents; bilateral severe medial tibiofemoral OA (KL = 4), no definite medial tibiofemoral OA (KL = 0, 1), BMI < 20 or > 45 kg^.m^-2

Medical history; physical exam; PA and skyline knee x-ray; height and weight.

OA disease location and alignment restrictions: predominant knee OA other than medial tibiofemoral OA; valgus, or extreme varus alignment.

Lateral tibiofemoral OA > medial tibiofemoral OA, severe patellofemoral OA; valgus knee alignment > 2°, or varus alignment > 10°

Knee PA and skyline view x-rays, lower extremity long x-ray.

Excess alcohol use

≥ 21 drinks per week

Questionnaire

Inability to finish 18-month study or unlikely to be compliant

Lives > 50 miles from site or planning to leave area ≥ 3 months during the next 18 months

Questionnaire, interview

Conditions that prohibit CT

BMI > 45 kg^.m^-2

height and weight

Significant cognitive impairment

diagnosis of dementia or a MoCA score <20

Medical history, MoCA

Low Pain

Pain ≤ 3 on a scale from 0-20

WOMAC