Petersen Kristian K, Simonsen Ole, Laursen Mogens B, Arendt-Nielsen Lars
SMI, Department of Health Science and Technology, Faculty of Medicine, Aalborg University.
Aalborg University Hospital, Orthopaedic Surgery Research Unit, Aalborg, Denmark.
Clin J Pain. 2018 Mar;34(3):193-197. doi: 10.1097/AJP.0000000000000528.
Knee osteoarthritis (KOA) can be associated with local and central sensitization. As an indicator of the central gain, facilitated temporal summation of pain (TSP) has been found in KOA patients. This facilitation is predictive of the development of chronic postoperative pain after total knee arthroplasty (TKA). Other studies have suggested hypoesthesia/hypoalgesia to thermal stimuli as a feature in KOA. This study investigated associations between preoperative TSP, thermal sensitivity, and radiologic severity for the development of chronic postoperative pain after TKA.
Radiologic KOA (Kellgren and Lawrence), TSP, and thermal stimuli were collected, preoperatively. Clinical knee pain intensity (VAS 0-10) was assessed before and 12 months following TKA. Patients were categorized into a chronic postoperative pain group if they experienced <30% pain reduction of the initial pain after 12 months.
In total, 19% of the patients were categorized as chronic pain patients and presented facilitated preoperative TSP (P<0.05) and a trend towards increased heat pain threshold (P=0.077) compared with patients with normal recovery. Pearson correlations found that preoperative TSP (R=0.193; P=0.013), Kellgren and Lawrence (R=-0.168; P=0.027), warm detection threshold (R=0.195; P=0.012), and heat pain threshold (R=0.196; P=0.012) were associated with pain intensity 12 months after TKA where TSP was identified as an independent factor.
This study showed that preoperatively facilitated TSP in KOA patients was predictive of the development of chronic postoperative pain following TKA. Furthermore, this study is the first to find an association between preoperative hypoalgesia to heat and the development of chronic postoperative pain following TKA.
膝关节骨关节炎（KOA）可能与局部和中枢敏化有关。作为中枢增益的指标，在KOA患者中发现了疼痛的易化性时间总和（TSP）。这种易化性可预测全膝关节置换术（TKA）后慢性术后疼痛的发生。其他研究表明，对热刺激的感觉减退/痛觉减退是KOA的一个特征。本研究调查了术前TSP、热敏感性和放射学严重程度与TKA后慢性术后疼痛发生之间的关联。
术前收集放射学KOA（Kellgren和Lawrence分级）、TSP和热刺激数据。在TKA术前和术后12个月评估临床膝关节疼痛强度（视觉模拟评分0 - 10分）。如果患者在12个月后疼痛减轻幅度小于初始疼痛的30%，则将其归类为慢性术后疼痛组。
总体而言，19%的患者被归类为慢性疼痛患者，与恢复正常的患者相比，他们术前TSP易化（P<0.05），热痛阈值有升高趋势（P = 0.077）。Pearson相关性分析发现，术前TSP（R = 0.193；P = 0.013）、Kellgren和Lawrence分级（R = -0.168；P = 0.027）、温觉检测阈值（R = 0.195；P = 0.012）和热痛阈值（R = 0.196；P = 0.012）与TKA术后12个月的疼痛强度相关，其中TSP被确定为独立因素。
本研究表明，KOA患者术前TSP易化可预测TKA后慢性术后疼痛的发生。此外，本研究首次发现术前对热的痛觉减退与TKA后慢性术后疼痛的发生之间存在关联。
