Creamer P, Hunt M, Dieppe P
Rheumatology Unit, Bristol Royal Infirmary, UK.
J Rheumatol. 1996 Jun;23(6):1031-6.
The causes of pain in osteoarthritis (OA) remain unclear. We examined the effect of intraarticular (IA) local anesthetic (LA) on pain perception in OA knee to test the hypothesis that pain arises from structures in contact with the intraarticular surface. The effect of intervention on one knee on perception of pain in the other was also studied.
Using a single blind, blind observer design, 20 subjects with bilateral symptomatic OA knee were randomized to receive either IA LA (bupivacaine 0.25%, 5 ml) or placebo into the most painful knee. Pain from both knees was assessed at 1 h, 24 h, and 7 days using a 100 mm visual analog scale (VAS). Pain descriptors using a standardized questionnaire (McGill) were recorded.
At 1 h there was a significant fall in pain in LA knees (median VAS 61.5 to 0.0; p = 0.007). The change at VAS was significantly different between knees receiving LA and placebo (median change -45.5 vs +3.5; p = 0.03). 6/10 LA knees scored 0 on VAS at 1 h. Noninjected knees also showed a fall in pain scores. For knees contralateral to those receiving LA, the fall was from median 28.0 to 1.0 (p = 0.08). The reduction in pain was much less in knees contralateral to those receiving placebo (median 43.5 to 38.0), though the difference between the changes did not reach statistical significance. VAS scores remained below baseline for 7 days, though this difference was not significant. McGill pain scores fell in the LA group (for all categories of pain), but did not change in the placebo group.
Pain in some cases of OA knee can be abolished by IA LA, suggesting that the structures responsible for pain are in contact with the intraarticular environment. As well, interventions in one knee have significant effects on pain perception in the contralateral knee.
骨关节炎（OA）疼痛的原因尚不清楚。我们研究了关节内（IA）局部麻醉剂（LA）对OA膝关节疼痛感知的影响，以检验疼痛源于与关节内表面接触的结构这一假设。还研究了对一侧膝关节的干预对另一侧膝关节疼痛感知的影响。
采用单盲、盲观察者设计，将20例双侧有症状的OA膝关节患者随机分为两组，分别向最疼痛的膝关节注射IA LA（布比卡因0.25%，5毫升）或安慰剂。使用100毫米视觉模拟量表（VAS）在1小时、24小时和7天时评估双膝的疼痛情况。使用标准化问卷（麦吉尔问卷）记录疼痛描述词。
1小时时，注射LA的膝关节疼痛显著下降（VAS中位数从61.5降至0.0；p = 0.007）。接受LA和安慰剂的膝关节在VAS上的变化有显著差异（中位数变化-45.5对+3.5；p = 0.03）。10个接受LA的膝关节中有6个在1小时时VAS评分为0。未注射的膝关节疼痛评分也有所下降。对于接受LA的对侧膝关节，疼痛评分从中位数28.0降至1.0（p = 0.08）。接受安慰剂的对侧膝关节疼痛减轻程度小得多（中位数从43.5降至38.0），尽管变化之间的差异未达到统计学显著性。VAS评分在7天内一直低于基线水平，尽管这种差异不显著。LA组的麦吉尔疼痛评分下降（所有疼痛类别），而安慰剂组未变化。
IA LA可消除部分OA膝关节的疼痛，提示引起疼痛的结构与关节内环境接触。此外，对一侧膝关节的干预对另一侧膝关节的疼痛感知有显著影响。
