Intra-articular morphine versus bupivacaine for knee motion among patients with osteoarthritis: randomized double-blind clinical trial.
OBJECTIVE
Osteoarthritis causes pain and disability in a high percentage of elderly people. The aim of the present study was to assess the efficacy of intra-articular morphine and bupivacaine on the joint flexion and extension angles of patients with knee osteoarthritis.


METHODS
A randomized double-blind study was performed at a pain clinic of Universidade Federal de São Paulo.


METHODS
Thirty-nine patients with pain for more than three months, of intensity greater than three on a numerical scale (zero to 10), were included. G1 patients received 1 mg (1 ml) of morphine diluted in 9 ml of saline, intra-articularly, and G2 patients received 25 mg (10 ml) of 0.25% bupivacaine without epinephrine. Pain was assessed on a numerical scale and knee flexion and extension angles were measured after administration of the drugs at rest and during movement. The total amount of analgesic supplementation using 500 mg doses of paracetamol was also determined.


RESULTS
No significant difference in pain intensity was observed between G1 and G2. Significant decreases in pain at rest and during movement and significant increases in mean flexion and extension angles were observed in both groups, with no significant difference between the two groups. The mean total amount of paracetamol used over a seven-day period was 3578 mg in G1 and 5333 mg in G2 (P = 0.2355; Mann-Whitney test).


CONCLUSIONS
The analgesic effects of 1 mg of morphine and 25 mg of 0.25% bupivacaine were similar among patients with osteoarthritis of the knee.
Gazi
Miriam Bellini
MB
Pain Outpatient Clinic, Hospital São Paulo, Universidade Federal de São Paulo, São Paulo, Brazil.
Sakata
Rioko Kimiko
RK
Issy
Adriana Machado
AM
D000368:Aged; D000701:Analgesics, Opioid / Q000008:administration & dosage*; D000704:Analysis of Variance; D000779:Anesthetics, Local / Q000008:administration & dosage*; D002045:Bupivacaine / Q000008:administration & dosage*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007270:Injections, Intra-Articular; D008124:Locomotion; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage*; D020370:Osteoarthritis, Knee / Q000188:drug therapy* / Q000503:physiopathology; D010147:Pain Measurement / Q000187:drug effects; D012146:Rest; D013997:Time Factors
D000701:Analgesics, Opioid; D000779:Anesthetics, Local; D009020:Morphine; D002045:Bupivacaine