Iovane A, Princiotta C, Giudice G, Lo Bello M, Caruso G, Lagalla R
Istituto di Radiologia, P. Cignolini, Università degli Studi, Palermo.
Radiol Med. 1995 Oct;90(4):367-73.
Posterior tibial tendon (PTT) tears are the most common cause of unilateral flatfoot in adults. It is a chronic pathologic condition with a degenerative inflammatory character which usually affects middle-aged or elderly women, with no history of trauma. PTT tears occur more rarely in young patients, after an acute traumatic event. Clinically, PTT tears present with pain along the tendon, increased by weight bearing, swelling and functional limitation. PTT tears are surgically classified in three types: with tendon hypertrophy, with tendon atrophy and with complete tendon tear. The three different anatomicosurgical patterns require different therapeutic approaches. This work was aimed at investigating MR capabilities in recognizing the direct and indirect signs of PTT tears, assessing MR sensitivity in different types of tears. Fourteen patients with clinically suspected PTT tears and 10 control patients underwent MRI of the ankle (0.5 T, GE Vectra) following a study protocol including SE T1-weighted and FSE T2-weighted scans acquired on the axial and sagittal planes. In all patients, the transverse diameter, the shape and the section surface of the lesions were calculated on the axial planes at different levels; all these parameters were compared with those of the adjacent tendons, i.e., flexor longus ditae and flexor hallucis. Moreover, the probable presence was investigated of intratendineous signal intensity changes, of peritendineous synovial fluid and of indirect signs of PTT tear, i.e., the lack of longitudinal talonavicular alignment and the bulging of the medial navicular tubercle. According to MR results, the 14 patients were subdivided into 8 patients with type-I tears, 2 with type-II tears and 4 patients with type-III tears. The measures of healthy and injured tendons were in substantial agreement: in fewer cases, agreement was found also between symptomatic and control patients with intratendineous signal changes. Thus, the specificity of the two parameters was reduced. Finally, such indirect signs of PTT tear as a hypertrophic navicular tubercle and the lack of longitudinal talonavicular alignment exhibited good specificity, but sensitivity was barely sufficient. MR diagnoses were confirmed at surgery in 6 patients with type-II and type-III tears. In conclusion, MRI appears to be a suitable modality for recognizing and classifying PTT tears and a useful tool for the treatment and follow-up of these patients.
胫后肌腱（PTT）撕裂是成人单侧扁平足最常见的原因。它是一种具有退行性炎症特征的慢性病理状况，通常影响中年或老年女性，且无创伤史。PTT撕裂在年轻患者中较少见，多发生于急性创伤事件后。临床上，PTT撕裂表现为沿肌腱疼痛，负重时加重，伴有肿胀和功能受限。PTT撕裂在手术中分为三种类型：肌腱肥大型、肌腱萎缩型和肌腱完全撕裂型。这三种不同的解剖手术模式需要不同的治疗方法。本研究旨在探讨磁共振成像（MR）识别PTT撕裂直接和间接征象的能力，评估MR对不同类型撕裂的敏感性。14例临床怀疑PTT撕裂的患者和10例对照患者按照研究方案接受了踝关节磁共振成像检查（0.5T，GE Vectra），检查包括在轴位和矢状位上进行的自旋回波（SE）T1加权和快速自旋回波（FSE）T2加权扫描。在所有患者中，在不同层面的轴位上计算病变的横径、形状和截面面积；将所有这些参数与相邻肌腱，即趾长屈肌腱和拇长屈肌腱的参数进行比较。此外，还研究了肌腱内信号强度变化、肌腱周围滑液以及PTT撕裂间接征象（即距舟关节纵向对线缺失和内侧舟骨结节隆起）的可能存在情况。根据MR结果，14例患者被分为8例I型撕裂、2例II型撕裂和4例III型撕裂。健康肌腱和损伤肌腱的测量结果基本一致：在较少情况下，有症状患者和对照患者在肌腱内信号变化方面也存在一致性。因此，这两个参数的特异性降低。最后，PTT撕裂的间接征象，如舟骨结节肥大和距舟关节纵向对线缺失，具有良好的特异性，但敏感性仅勉强足够。6例II型和III型撕裂患者的MR诊断在手术中得到证实。总之，MRI似乎是识别和分类PTT撕裂的合适方式，也是这些患者治疗和随访的有用工具。
