Spring ligament in acquired adult flat foot deformity: static and dynamic sonographic evaluation

Transcription

1 Spring ligament in acquired adult flat foot deformity: static and dynamic sonographic evaluation Poster No.: P-0030 Congress: ESSR 2013 Type: Scientific Exhibit Authors: E. GALLARDO AGROMAYOR, H. Vidal Trueba, B. González Humara, R. M. LANDERAS, R. Garcia Barredo, M. R. DE LA PUENTE FORMOSO ; Santander, CANTABRIA/ES, Santander/ ES Keywords: Education and training, Technical aspects, Ultrasound, Musculoskeletal soft tissue DOI: /essr2013/P-0030 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 22

2 Purpose Recognize the normal sonoanatomy of the static and dynamic stabilizers of the medial longitudinal arch pf the foot: porterior tibial tendon, calcaneonavicular ligament and sinus tarsi ligaments. ( Fig. 1) Illustrate the main findings of the spring ligament degeneration and rupture in patients with acquired flatfoot deformity. Propose a systematic exploration with a static and dynamic ecographic approach in patients with suspicion of posterior tibial tendon insuficciency Methods and Materials During the last three years, we prospectively reviewed the sonographic findings in patients referred to our department, from an orthopaedic surgeon, with a clinical diagnosis of flat foot (FF) due to posterior tibial insufficiency or pain in the medial aspect of the ankle with physical examination and radiographs consistent with flatfoot assessed at the moment of ultrasound examination. All of them during the initial phase of the disease. We performed a systematic exploration of the ankle with a high linear array transducer (8-13 MHz), focused on the evaluation of the medial stabilizers, posterior tibial tendon (PTT) and calcaneonavicular ligament or spring ligament complex (SLC). Sonographic technique of the SLC was the same reported in other works. (Fig.1) Ultrasound criteria for diagnosing PTT tendinosis are widely described. We considered signs of degeneration of the spring ligament the decrease of its echogenicity, increase of thickness in the axial scan, >4mm, and the presence of loss of fibrillar pattern and even fiber disruption. We evaluated the presence of peritalar destabilization in all patients, measuring the medial talus bone motion from the sitting position to the standing position (fig. 2). For this purpose, we based on the coxa pedis model (Fig. 3(3,4)); we measured the talar head coverage and medial subluxation as it is explained in figure 4 (5-8). We considered normal when talar head location maintains lateral to the medial cortex of the navicular bone, medial subluxation when there is an adduction movement of the talus bone, leaving its head partially uncovered. Page 2 of 22

3 Images for this section: Fig. 1 Page 3 of 22

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11 Results We reviewed 47 cases in 38 patients, 27 women and 11 men, age range from 20 to 72 years and mean age of 54 years. PTT signs of tendinosis were present in 28 of the 47 (59,5%) studied ankles and the spring ligament was abnormal in 41 of them (87,2%) (Fig. 5(9)). The most affected area of the SLC was the distal part of the superomedial component in all cases and we visualized a fibrillar disruption in 13 out of the 41cases (Figs. 6-8(10-12)). The evaluation of the peritalar destabilization demonstrated the following data: a) In 9 ankles there were no movement of the talar head from the sitting to the standing position. All of them showed degeneration signs of SLC without rupture; only in 2 cases (22%) there were abnormalities of the PTT. (Fig.9(13)) b) In 13 cases a clear movement of the talar head was visualized, always in adduction. Degeneration signs of the spring ligament was assessed in 81% and 27% of them were distally rupture. 63 % of them had also TTP degeneration. (Fig.10(14)) c) Finally there were 25 cases with medial subluxation of the talar head. Degeneration signs of the SL was assessed in 95% of the cases and 63% of them were distally rupture. In this group tendinosis of the PTT was reported in 50% of the cases. (Figs. 11,12 (15,16)) Images for this section: Page 11 of 22

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20 Conclusion The stimulus for this investigation was our belief that the treatment of symptomatic flat foot in adults was not always based on objective data. We focused our study on the assessment of spring ligament degeneration and peritalar destabilization in an attempt to clarify two main points: first, the radiological literature of the acquired adult flat foot is based on the study of the posterior tibial tendon and PTT insufficiency is considered the main cause of this disorder, however imaging techniques may show no abnormalities in this structure. Secondly, in the last decade the spring ligament complex has raised an important role in the study and treatment planning of patients with this disorder, mainly in the early stage of the disease. However, preoperative integrity of the functional spring ligament is difficult to determine by physical examination alone. For the design of this study we considered two important functions of the SLC: First, it supports the head of the talus, forming the medial and plantar parts of the articular cavity of the talar head. The articular cavity of the talar head is also called the acetabulum pedis or "coxa pedis". This complex cavity consists of the anterior and middle articular facets of the calcaneus, the proximal articular surface of the navicular bone, and the spring ligament complex. Besides that, the contiguous skeletal relations of the talus bone with the navicular and calcaneus and the absence of muscular insertions; cause the pull of gravity to stimulate talar adduction and plantar flexion. Second, the spring ligament-together with the PTT, the plantar fascia, and the plantar ligaments- is an important stabilizer of the longitudinal arch of the foot. Lesions in these structures can result in flatfoot deformity. In our study, all patients were referred, specifically, for flat foot with suspected PTT insufficiency, however tendinosis ot that tendon was assessed only in 59,5% of the ankles, whereas a significant degeneration of the SLC was visualized in 87% of the cases; demonstrating the capital importance of this ligament complex on its own, in maintaining the normal alignment and height of the medial longitudinal arch. Abnormality of the spring ligament has a high association with advanced posterior tibial tendon injury; in our study 92% of our patients with PTT tendinosis has also signs of SLC degeneration. It is generally assumed that degeneration of SLC is secondary to the dynamic stabilizers tendons, however this study shows that degeneration signs are more frequently visualized in SLC than in PTT, in this entity. The larger superomedial component plays the most significant role in the contribution of the spring ligament to ankle stability and is the component most often torn; as we corroborate in our study: the degeneration signs were more pronounced distally within the ligament and all of the ruptures were visualized that area. Page 20 of 22

21 Other important fact that we considered in this study, was the theory of Pisani about the peritalar destabilisation as a development deficiency, of one or more, of the stabilising components of the coxa pedis: a)the intrinsic articular disease that is often degenerative; b) a myotendinous disease that is frequent in the posterior tibial tendon; and c) loss of passive stability by superomedial and plantar calcaneonavicular ligaments, the last one known as degenerative glenopathy. While standing upright the ligamentous structures guarantee, passively, peritalar stabilisation. In this study, we attempted to demonstrate this later fact measuring the talar adduction on standing position: we assessed destabilisation more frequently in cases with both SLC degeneration and PTT tendinosis; additionally, in those patients with clear adduction of the talar head while standing, was more frequent the rupture of the SLC. We proposed a new way to objectify and measure the peritalar destabilization, with a dynamic sonographic study; more studies are necessary to confirm these findings and to standardize the normal values of range motion in general population. In conclusion, ultrasound is an accurate technique in the evaluation of the spring ligament, and its signs of degeneration are more frequently visualized than PTT tendinosis in patients with acquired flat foot in their initial phases. We consider that the dynamic sonographic evaluation of talar adduction would be useful for a more accurate surgical planning. References Balen PF, Helms CA. Association of posterior tibial tendon injury with spring ligament injury, sinus tarsi abnormality, and plantar fasciitis on MR imaging. AJR 2001 ;176: Borton DC, Saxby TS. Tear of the plantar calcaneonavicular (spring) ligament causing flatfoot. A case report. J Bone Joint Surg B 1997;79: Chen JP, Allen AM. MR diagnosis of traumatic tear of the spring ligament in a pole vaulter. Skeletal Radiol 1997; 26: Davis H, Sobel M, DiCarlo EF, et al. Gross, histological and microvascular anatomy and biochemical testing of the spring ligament complex. Foot Ankle Int 1996;17: Deland JT. The adult acquired flatfoot and spring ligament complex: pathology and implications for treatment. Foot Ankle Clin 2001; 6: Page 21 of 22

22 Harish S, Jan E, Finlay K, Petrisor B, Popowich T, Friedman L, et al. Sonography of the superomedial part of the spring ligament complex of the foot: a study of cadavers and asymptomatic volunteers. Skeletal Radiol 2007; 36(3): Mansour R, Teh J, Sharp RJ and Ostlere S. Ultrasound assessment of the spring ligament complex. Eur Radiool 2008; 18: Melao L, Canella C, Weber M, Negrao P, Trudell D, Resnick D. Ligaments of the transverse tarsal joint complex: MRI-Anatomic correlation in cadavers. Mengiardi B, Zanetti M, Scho ttle PB, Vienne P, Bode B, Hodler J,et al. Spring ligament complex: MR imaging-anatomic correlation and findings in asymptomatic subjects. Radiology 2005;237: Pisani G.The coax pedis. Eur J Ankle surg 1994;1:67-74 Pisani G. Peritalar destabilisation syndrome ( adult flatfoot with degenerative glenopathy. Foot and Ankle Surgery. 2010; 16: Rule J, Yao L, Seeger LL. Spring ligament of the ankle: normal MR anatomy. AJR 1993; 161: Toye L, Helms C, Hoffman B, Easley M, Nunley J. MRI of Spring Ligament Tears. AJR 2005; 184: Tryfonidis M, Jackson W, Mansour R, Cooke PH, The J, Ostlere S et al. Acquired adult flat foot due to isolated plantar calcaneonavicular (spring) ligament insufficiency with a normal tibialis posterior tendon. Foot and ankle surgery 2007; 14: Yao L, Gentili A, Cracchiolo A. MR imaging findings in spring ligament insufficiency.skeletal Radiol 1999; 28: Personal Information Page 22 of 22