Movement discrimination after intra-articular local anaesthetic of the ankle joint.
BACKGROUND
The effect on clinical safety of dampening articular mechanoreceptor feedback at the ankle is unknown. Injection of the ankle joint for pain control may result in such dampening. Athletes receiving intra-articular local anaesthetic may therefore be at increased risk of sustaining ankle injuries, which are a common reason for missed sporting participation.


OBJECTIVE
To determine the effect of intra-articular local anaesthetic on movement discrimination at the ankle joint.


METHODS
Prospective, randomised, double-blinded, placebo-controlled, cross-over trial.


METHODS
Australian Institute of Sport Medical Centre, Canberra, Australia.


METHODS
Twenty two healthy subjects (44 ankles) aged 18-26 were recruited for the three visits of the study.


METHODS
Subjects were tested for their initial movement discrimination scores using the active movement extent discrimination apparatus (AMEDA). They then received ultrasound-guided intra-articular injections of local anaesthetic (2% lignocaine hydrochloride) or normal saline, on two separate later occasions, before further AMEDA assessment.


METHODS
Change in movement discrimination scores after intra-articular injection of local anaesthetic or saline.


RESULTS
Movement discrimination scores were not significantly different from control ankles after injection of either local anaesthetic or saline into the ankle joint.


CONCLUSIONS
The intra-articular injection of neither 2 ml lignocaine nor an equivalent amount of normal saline resulted in significant effects on movement discrimination at the ankle joint. These results suggest that injections of local anaesthetic into the ankle joint are unlikely to significantly affect proprioception and thereby increase injury risk.
Down
Stuart
S
Sports Medicine, Education & Technology, Australian Institute of Sport, Bruce, ACT, Australia. stu_down@yahoo.com.au
Waddington
Gordon
G
Adams
Roger
R
Thomson
Malcolm
M
D000293:Adolescent; D000328:Adult; D000779:Anesthetics, Local / Q000008:administration & dosage* / Q000009:adverse effects; D016512:Ankle Injuries / Q000188:drug therapy* / Q000517:prevention & control; D019540:Area Under Curve; D001265:Athletic Injuries / Q000517:prevention & control; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007270:Injections, Intra-Articular; D008012:Lidocaine / Q000008:administration & dosage* / Q000009:adverse effects; D008297:Male; D009068:Movement / Q000187:drug effects; D010147:Pain Measurement / Q000187:drug effects; D011336:Probability; D011434:Proprioception / Q000187:drug effects*; D011446:Prospective Studies; D016059:Range of Motion, Articular / Q000187:drug effects* / Q000502:physiology; D012016:Reference Values; D018570:Risk Assessment
D000779:Anesthetics, Local; D008012:Lidocaine