Pain and recovery after total knee arthroplasty: a 12-month follow-up after a prospective randomized study evaluating Nefopam and Ketamine for early rehabilitation.
OBJECTIVE
Ketamine and nefopam has been documented to decrease pain intensity and improve rehabilitation after total knee arthroplasty (TKA). We conducted a follow-up study of a previously randomized clinical trial to determine the prevalence and risk factors of chronic pain 1 year after TKA and to assess the role of perioperative administration of ketamine and nefopam.


METHODS
The original randomized, double-blind trial evaluated postoperative pain in 75 patients scheduled for TKA who received either a 48-hour infusion of ketamine or nefopam compared with placebo. The current study has evaluated patients at 6 and 12 months for the presence of chronic pain defined as a visual analogue scale ≥40 mm during a stair-climbing test. Other outcomes were incidence of neuropathic pain evaluated (DN4 score), active flexion of the knee, and functional outcome (KOOS-PS score).


RESULTS
A total of 69 patients completed the trial. The prevalence of chronic pain at 12 months was 17.4% (95% confidence interval [CI], 10.2%-27.9%) without difference between the ketamine (12.5%), nefopam (13.7%), and placebo groups (26.1%). Prevalence of neuropathic pain was 10.2% (95% CI, 3%-17.3%). Ketamine reduced DN4 scores (P=0.02), increased knee flexion (P=0.0007), and KOOS-PS scores (P<0.0001) compared with placebo. A visual analogue scale score ≥60 mm in the postoperative period was the only risk factor associated with the occurrence of chronic pain (odds ratio 4.54; 95% CI, 1.17-17.67).


CONCLUSIONS
After TKA, the intensity of postoperative pain is a risk factor of chronic pain on movement. Intraoperative ketamine seems to improve long-term results of rehabilitation in this setting.
*Department of Anesthesiology and Intensive Care, Centre Hospitalier Privé Sévigné, Cesson-Sévigné †Department of Anesthesiology and Intensive Care, Tenon University Hospital, Université Pierre & Marie Curie Paris VI, Paris, France.
Christophe
C
Aveline
Alain Le
AL
Roux
Hubert Le
HL
Hetet
Jean F
JF
Gautier
Pierre
P
Vautier
Fabrice
F
Cognet
Francis
F
Bonnet
D000368:Aged; D000700:Analgesics / Q000627:therapeutic use*; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects / Q000534:rehabilitation*; D059350:Chronic Pain / Q000453:epidemiology / Q000517:prevention & control*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007649:Ketamine / Q000627:therapeutic use*; D007719:Knee Joint / Q000187:drug effects / Q000503:physiopathology / Q000601:surgery; D008137:Longitudinal Studies; D008297:Male; D009340:Nefopam / Q000627:therapeutic use*; D009437:Neuralgia / Q000453:epidemiology / Q000517:prevention & control; D010149:Postoperative Pain / Q000453:epidemiology / Q000517:prevention & control; D019990:Perioperative Care / Q000379:methods*; D015995:Prevalence; D016059:Range of Motion, Articular / Q000187:drug effects / Q000502:physiology; D020127:Recovery of Function / Q000187:drug effects / Q000502:physiology; D012307:Risk Factors
D000700:Analgesics; D009340:Nefopam; D007649:Ketamine