理解的对吗？

NSAIDs, through their inhibition of COX-1 and COX-2 isoenzymes as discussed earlier in this chapter, may have a perceived benefit in low back pain as well. Examples of topically available NSAIDs included diclofenac (available in gel, solution or patch form) and ketoprofen. A systematic review was carried out to determine the safety and efficacy of topical NSAIDs for chronic musculoskeletal pain in adults [137]. Most of the RCTs included in this review considered patients with knee osteoarthritis, with some studies including patients with more poorly defined pain diagnoses. Data was sufficient to pool only for diclofenac and ketoprofen in the systematic review. The authors conclude that topical diclofenac and ketoprofen can provide good levels of pain relief beyond that imparted by the carrier in osteoarthritis for only a minority of patients. Evidence for its efficacy in other chronic painful conditions is absent. There is some evidence to suggest that there is long-term benefit from the placebo effect derived from the carrier itself and that NSAIDs may augment this [137]. One study by Hohmeister, however, specifically included patients with cervical and lumbar back pain [138]. Flufenamate 3% plus salicylate 2% gel (Mobilisin) was administered three times daily to patients for 3 weeks and compared with placebo gel. The number of patients with patient global evaluations that were either very good or good in the topical NSAID group was higher (44/49) compared to the placebo group (4/51).

如本章已讨论的，NSAIDs通过抑制COX-1和COX-2同工酶可能使腰痛患者获益，局部可用的NSAIDs包括双氯芬酸（凝胶、溶液或贴片）和酮洛芬。已进行了一项外用NSAIDs治疗成人慢性肌肉骨骼疼痛是否安全和有疗的系统性综述[137]。这项综述中的大多数随机对照研究纳入的是膝骨关节炎患者，而另一些研究纳入了疼痛诊断更不明确的患者。但数据仅足以汇总分析双氯芬酸和酮洛芬，作者得出结论，局部双氯芬酸和酮洛芬可以提供良好的疼痛缓解水平，超过载体在骨关节炎中仅对少数患者产生的疼痛缓解水平。尚缺乏其对其他慢性疼痛性疾病的疗效证据。有一些证据表明，局部用药载体本身产生的安慰剂效应具有长期获益，NSAIDs可能会增强这种获益[137]。然而，Hohmeister的一项特别包括颈腰背痛患者的研究[138]，治疗组用3%氟芬那酯加2%水杨酸凝胶(Mobilisin)每日3次给药，持续3周，并与安慰剂凝胶进行比较。局部NSAIDs组患者总体评价为非常好或良好的患者数量(44/49)高于安慰剂组(4/51)。

理解的对吗？

 topical diclofenac and ketoprofen can provide good levels of pain relief beyond that imparted by the carrier in osteoarthritis for only a minority of patients. 尤其是这句话

还有however然而，这里感觉是顺承的关系，为啥用转折呢？