Knee OA: which patients are unlikely to benefit from manual PT and exercise?
BACKGROUND
The combination of manual physical therapy and exercise provides important benefit for more than 80% of patients with knee osteoarthritis (OA). Our objective was to determine predictor variables for patients unlikely to respond to these interventions.


METHODS
We used a retrospective combined cohort study design to develop a preliminary clinical prediction rule (CPR). To determine useful predictors of nonsuccess, we used an extensive set of 167 baseline variables. These variables were extracted from standardized examination forms used with 101 patients(64 women and 37 men with a mean age of 60.5}11.8 and 63.6}9.3 years, respectively) in 2 previously published clinical trials. We classified patients based on whether they achieved a clinically meaningful benefit of at least 12%improvement in Western Ontario MacMaster(WOMAC) scores after 4 weeks of treatment using the smallest and most efficient subset of predictors.


RESULTS
The variables of patellofemoral pain, anterior cruciate ligament laxity, and height >1.71 m (5’7’’) comprise the CPR. Patients with at least 2 positive tests yield eda posttest probability of 88% for nonsuccess with this treatment (positive likelihood ratio=36.7). The overall prognostic accuracy of the CPR was 96%.


CONCLUSIONS
Most patients with knee OA will benefit from a low-risk, cost-effective program of manual physical therapy and supporting exercise.1,2 The few patients who may not benefit from such a program are identifiable by a simple (preliminary) CPR. After validation,this rule could improve primary patient management,allowing more appropriate referrals and choices in intervention.
Army-Baylor University, Post-Professional Doctoral Fellowship Program in Orthopedic Manual Physical Therapy, Brooke Army Medical Center, Ft. Sam Houston, TX, USA. gail.deyle@amedd.army.mil
Gail D
GD
Deyle
Norman W
NW
Gill
Stephen C
SC
Allison
Benjamin R
BR
Hando
Duneley A
DA
Rochino
D000368:Aged; D018712:Analgesics, Non-Narcotic / Q000008:administration & dosage / Q000009:adverse effects; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000009:adverse effects; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism; D015331:Cohort Studies; D052246:Cyclooxygenase 2 Inhibitors / Q000008:administration & dosage / Q000009:adverse effects; D004359:Drug Therapy, Combination; D005081:Exercise Therapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D026201:Musculoskeletal Manipulations / Q000379:methods; D020370:Osteoarthritis, Knee / Q000097:blood / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D059408:Pain Management / Q000379:methods; D011237:Predictive Value of Tests; D016059:Range of Motion, Articular; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome
D018712:Analgesics, Non-Narcotic; D000894:Anti-Inflammatory Agents, Non-Steroidal; D015415:Biomarkers; D052246:Cyclooxygenase 2 Inhibitors; D002097:C-Reactive Protein