Yi Anthony, Kennedy Colin, Chia Benjamin, Kennedy Stephen A
Department of Orthopaedics and Sports Medicine, University of Washington, Harborview Medical Center, Seattle, WA.
Department of Orthopaedics and Sports Medicine, University of Washington, Harborview Medical Center, Seattle, WA.
J Hand Surg Am. 2019 May;44(5):394-399. doi: 10.1016/j.jhsa.2019.01.013. Epub 2019 Feb 21.
Characteristic swelling has been described as a differentiating sign of pyogenic flexor tenosynovitis (PFT) but has not been validated. We conducted a retrospective study of adults with finger infections to compare radiographic parameters of soft tissue dimensions. Our hypothesis was that in patients with digit infections, radiographic soft tissue thickness measurement would differ between PFT and non-PFT infected digits.
Patients with a finger infection and radiographic evaluation were identified retrospectively at a large academic medical center and divided into 2 groups: PFT (n = 31) and non-PFT infections (n = 31). We defined PFT as purulence in the tendon sheath or positive culture growth from the sheath at surgery. Non-PFT infections included all other finger infections such as abscesses and cellulitis. A total of 15 radiographic measurements were made on all included digits. Ratios and differences were calculated to characterize the pattern of swelling for each infected finger. Bivariate analysis was performed to identify potential predictor variables between the PFT and non-PFT groups. Logistic regression was performed to reduce confounding and model potential relationships.
Neither presence of diffuse swelling nor the shape of finger swelling distinguished PFT from non-PFT infections. All finger infections resulted in diffuse swelling. Pyogenic flexor tenosynovitis was distinguished by differential volar soft tissue thickness minus dorsal soft tissue thickness on radiographs at the proximal phalanx level (9 ± 1 mm for PFT vs 5 ± 1 mm for non-PFT). This was an independent predictor of PFT. The area under the receiver operating curve was 0.83 (95% confidence interval, 0.73-0.94). A difference between volar and dorsal soft tissue swelling of 7 mm or greater had a positive predictive value of 82% with a sensitivity of 84% and specificity of 74%. A difference of 10 mm predicted PFT infection with 76% probability (95% confidence interval, 73% to 99%).
Pyogenic flexor tenosynovitis may result in uniform finger swelling, but this does not appear to distinguish PFT from other finger infections. Acute PFT swelling is distinguished by differential volar versus dorsal radiographic soft tissue thickness at the level of the proximal phalanx. The term "fusiform swelling" is a misnomer for the appearance of acute PFT because the finger is not spindle-shaped.
TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic IV.
特征性肿胀已被描述为化脓性屈指肌腱腱鞘炎（PFT）的鉴别体征，但尚未得到验证。我们对患有手指感染的成年人进行了一项回顾性研究，以比较软组织尺寸的影像学参数。我们的假设是，在手指感染患者中，PFT感染手指与非PFT感染手指的影像学软组织厚度测量结果会有所不同。
在一家大型学术医疗中心对有手指感染并进行了影像学评估的患者进行回顾性识别，并将其分为两组：PFT组（n = 31）和非PFT感染组（n = 31）。我们将PFT定义为腱鞘内有脓性分泌物或手术时腱鞘培养有阳性生长。非PFT感染包括所有其他手指感染，如脓肿和蜂窝织炎。对所有纳入的手指进行了总共15项影像学测量。计算比值和差值以描述每个感染手指的肿胀模式。进行双变量分析以确定PFT组和非PFT组之间的潜在预测变量。进行逻辑回归以减少混杂因素并建立潜在关系模型。
弥漫性肿胀的存在与否以及手指肿胀的形状均无法区分PFT和非PFT感染。所有手指感染均导致弥漫性肿胀。化脓性屈指肌腱腱鞘炎的特征是在近端指骨水平的X线片上，掌侧软组织厚度减去背侧软组织厚度存在差异（PFT组为9±1mm，非PFT组为5±1mm）。这是PFT的独立预测因素。受试者工作特征曲线下面积为0.83（95%置信区间，0.73 - 0.94）。掌侧和背侧软组织肿胀差值为7mm或更大时，阳性预测值为82%，敏感性为84%，特异性为74%。差值为10mm时，预测PFT感染概率为76%（95%置信区间，73%至99%）。
化脓性屈指肌腱腱鞘炎可能导致手指均匀肿胀，但这似乎无法将PFT与其他手指感染区分开来。急性PFT肿胀的特征是在近端指骨水平掌侧与背侧影像学软组织厚度存在差异。术语“梭形肿胀”用于描述急性PFT的外观是错误的，因为手指并非纺锤形。
研究类型/证据水平：诊断性IV级。
