Rathleff Michael Skovdal, Rathleff Camilla Rams, Stephenson Aoife, Mellor Rebecca, Matthews Mark, Crossley Kay, Vicenzino Bill
Research Unit for General Practice in Aalborg, Department of Clinical Medicine at Aalborg University, Aalborg University, Aalborg, Denmark.
Orthopaedic Surgery Research Unit, Aalborg University Hospital, Aalborg, Denmark.
PLoS One. 2017 Dec 8;12(12):e0188930. doi: 10.1371/journal.pone.0188930. eCollection 2017.
Patellofemoral Pain (PFP) is highly prevalent among adults and adolescents. Localized mechanical hyperalgesia around the knee and tibialis anterior have been observed in people with PFP, but limited knowledge of potential manifestations of central sensitisation exists. The aims of this study were to study conditioned pain modulation (CPM) and wide-spread hyperalgesia in adults with PFP. This assessor-blinded cross-sectional study design compared CPM and mechanical pressure pain thresholds (PPT) between 33 adults (23 females) diagnosed with PFP and 32 age and sex matched pain-free controls. The investigator taking the PPT measurements was blinded to which participants had PFP. PPTs were reliably measured using a Somedic hand-held pressure algometer at three sites: 1) The centre of the patella, 2) the tibialis anterior muscle and 3) a remote site on the lateral epicondyle. For the assessment of CPM, experimental pain was induced to the contralateral hand by immersion into a cold water bath (conditioning stimulus), and assessment of PPTs (the test stimulus) was performed before and immediately after the conditioning stimulation. On average, the CPM paradigm induced a significant increase in PPTs across the three sites (6.3-13.5%, P<0.05), however there was no difference in CPM between young adults with PFP compared to the control group, (F(1,189) = 0.39, P = 0.89). There was no difference in mechanical PPTs between the two groups (F(1,189) = 0.03, P = 0.86). Contrary to our a-priori hypothesis, we found no difference in CPM or PPT between young adults with PFP and age and sex matched pain-free controls.
髌股疼痛（PFP）在成年人和青少年中极为普遍。在患有PFP的人群中，已观察到膝盖周围和胫前肌存在局部机械性痛觉过敏，但对中枢敏化潜在表现的了解有限。本研究的目的是研究患有PFP的成年人的条件性疼痛调制（CPM）和广泛痛觉过敏。这项评估者盲法横断面研究设计比较了33名被诊断为PFP的成年人（23名女性）与32名年龄和性别匹配的无痛对照组之间的CPM和机械压力疼痛阈值（PPT）。进行PPT测量的研究者对哪些参与者患有PFP不知情。使用Somedic手持式压力痛觉计在三个部位可靠地测量PPT：1）髌骨中心；2）胫前肌；3）外侧髁上的一个远端部位。为了评估CPM，通过将对侧手浸入冷水浴（条件刺激）来诱发实验性疼痛，并在条件刺激之前和之后立即进行PPT评估（测试刺激）。平均而言，CPM范式在三个部位均使PPT显著增加（6.3 - 13.5%，P<0.05），然而，患有PFP的年轻人与对照组之间的CPM没有差异（F(1,189) = 0.39，P = 0.89）。两组之间的机械PPT没有差异（F(1,189) = 0.03，P = 0.86）。与我们的先验假设相反，我们发现患有PFP的年轻人与年龄和性别匹配的无痛对照组之间在CPM或PPT方面没有差异。
