Center for General Practice at Aalborg University, Aalborg, Denmark.
SMI, Department of Health Science and Technology, Faculty of Medicine, Aalborg University, Aalborg, Denmark.
Pain. 2020 May;161(5):1065-1071. doi: 10.1097/j.pain.0000000000001796.
Patellofemoral pain (PFP) is a common complaint among young sports active adolescents. This study evaluated the longitudinal changes in pronociceptive and antinociceptive mechanisms in young adolescents with PFP, their impact on prognosis, and responsiveness to treatment. Adolescents (N = 151, aged 10-14 years) diagnosed with PFP were compared with age-matched controls (N = 50) and subsequently tracked while participating in an intervention focussed on activity modification. They underwent quantitative sensory testing at baseline (preintervention), 4 weeks (during initial treatment), and 12 weeks (after treatment). Pressure pain thresholds (PPTs) were recorded on the knee, shin, and elbow. Temporal summation of pain (TSP) was assessed by the increase in pain intensity during 10 repeated cuff pressure pain stimulations on the leg. Conditioned pain modulation (CPM) was defined as change in cuff pain thresholds on one leg, during painful cuff conditioning on the contralateral leg. At baseline, adolescents with PFP had decreased PPTs at the knee, shin, and elbow (P < 0.001) as well as more facilitated TSP (P < 0.05) compared with controls. For CPM at baseline, controls displayed an increase in cuff pain thresholds during conditioning (P < 0.05), while those with PFP did not. More facilitated baseline TSP was associated with less improvements in pain intensity during the intervention (P < 0.01). Pressure pain thresholds increased at both follow-ups (P < 0.001), and the increased PPTs were associated with decreases in pain intensity (r = 0.316; P < 0.001). Overall, TSP remained facilitated at follow-ups, and there was no change in CPM. This is the first study to demonstrate a pronociceptive mechanism as a prognostic factor in young adolescents with PFP.
髌股疼痛综合征（PFP）是青少年运动员中常见的抱怨。本研究评估了 PFP 青少年中伤害感受性和抗伤害感受性机制的纵向变化，及其对预后的影响和对治疗的反应性。将诊断为 PFP 的青少年（N=151，年龄 10-14 岁）与年龄匹配的对照组（N=50）进行比较，随后在参与以活动调整为重点的干预措施时进行跟踪。他们在基线（干预前）、4 周（初始治疗期间）和 12 周（治疗后）进行定量感觉测试。在膝盖、胫骨和肘部记录压力疼痛阈值（PPT）。通过在腿部 10 次重复袖带压力疼痛刺激期间疼痛强度的增加来评估疼痛时间总和（TSP）。条件性疼痛调制（CPM）定义为在对侧腿部疼痛袖带条件下，一条腿的袖带疼痛阈值的变化。基线时，与对照组相比，PFP 青少年的膝盖、胫骨和肘部的 PPT 降低（P<0.001），TSP 更容易（P<0.05）。对于基线时的 CPM，对照组在条件作用期间显示出袖带疼痛阈值的增加（P<0.05），而 PFP 组则没有。TSP 更容易增加与干预期间疼痛强度的改善减少相关（P<0.01）。在两个随访中 PPT 均增加（P<0.001），并且增加的 PPT 与疼痛强度的降低相关（r=0.316；P<0.001）。总的来说，TSP 在随访中仍然容易发生，而 CPM 没有变化。这是第一项研究表明伤害感受性机制是 PFP 青少年预后的一个预测因素。
