Ultrasound and MRI Findings of Tennis Leg with Differential Diagnosis. Poster No.: R-0057 Congress: 2015 ASM Type: Educational Exhibit Authors: M. George, A. Thomas, R. Dutta, K. Gummalla; Singapore/SG Keywords: Education, Ultrasound, MR, Musculoskeletal soft tissue, Extremities, Athletic injuries DOI: 10.1594/ranzcr2015/R-0057 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 RANZCR's endorsement, sponsorship or recommendation of the third party, information, product or service. RANZCR 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 RANZCR 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,.doc documents and any other multimedia files are not available in the pdf version of presentations. Page 1 of 18
Learning objectives -Anatomy of the calf muscles. -Discuss the mechanism of injury of tennis leg and differential diagnosis. -Recognise the Ultrasound and MRI findings of tennis leg. Background Introduction Tennis leg is a clinical condition first described by Powell in 1883. It is fairly common and is not restricted to tennis players, although it has a high prevalence in this sport. It is usually an avulsion type of injury and is an important cause of a painful calf. Tennis leg is used generally to include injuries of the medial head of gastrocnemius, soleus muscle or plantaris. Earlier plantaris rupture was thought to be the main cause of tennis leg. But surgical and autopsy studies eventually clarified that the most common lesion causing tennis leg is an avulsion injury of the gastrocnemius. Associated soleus injury is also common. An isolated tear of the plantaris tendon is exceedingly rare. Plantaris is a vestigial muscle and its rupture does not result in any significant loss of function. It is a self-healing condition. It is important to differentiate plantaris rupture from other calf muscle injuries since injuries to the gastrocnemius and soleus generally are more severe and require longer time to heal. Page 2 of 18
Anatomy Posterior compartment of the leg is divided into superficial and deep muscle groups. -The superficial muscle group includes the gastrocnemius, soleus, and plantaris muscles (Fig 1). -The deep crural group includes the tibialis posterior, flexor hallucis longus, and flexor digitorum longus muscles. The medial head of the gastrocnemius originates from the posterior aspect of the medial femoral condyle, while the lateral head from the lateral femoral condyle.distally, the medial head merges with the lateral head. Further distally, this merges with the soleus muscle to form the Achilles tendon. Soleus originates from the back of fibular head and upper 1/3 of posterior surface of fibula and middle 1/3 of medial border of tibia. Distally it merges with gastrocnemius to form Achilles tendon. The plantaris muscle originates superior and medial to the lateral head of gastrocnemius origin. It continues deep to the lateral head of gastrocnemius. The tendon lies between the medial head of gastrocnemius and soleus muscles. It insert either anteromedially on Achilles or on the calcaneum. Pathology The gastrocnemius muscle is more prone to tears due to the higher proportion of type II fibers. These fibers are required for rapid actions such as jumping, running, etc. The gastrocnemius and plantaris muscles are overstretched by dorsiflexion of the ankle with the knee in full extension. This results in simultaneous active contraction and passive stretching of the gastrocnemius and plantaris leading to injury. Clinical features Classical clinical manifestation - middle aged person - with sports related acute pain Page 3 of 18
- acute pain in the middle portion of the calf - pop sound with associated pain and swelling. - a palpable mass may be felt caused due to haematoma. Images for this section: Fig. 1: T1 axial section through the calf. Normal appearance of medial head of gastrocnemius (star), lateral head of gastrocnemius (arrow) and plantaris tendon (arrow head).the soleus muscle is seen deep to plantaris tendon. Page 4 of 18
Imaging findings OR Procedure details Ultrasound and MRI are the preferred modalities and can accurately identify and assess the severity of the tear. Necessary to rule out other causes of calf pain. Ultrasound is easily available, quick, cheap, and easy to perform. MRI gives extensive view of the injury. Injuries of other adjacent muscles are also easily identified with MRI. Ultrasound Imaging Partial muscle rupture is seen as localized disruption or discontinuity of muscle fibers (Fig 2,3,4). Complete rupture involves disruption of the entire muscle with a gap between the torn ends. Fluid collection (Fig 5) / hematomas (Fig 2,3,4) deep to medial gastrocnemius and superficial to the soleus muscle most prominent at the level of the myotendinous junction. Disruption of the normal pennate appearance of the medial head of gastrocnemius and indistinct appearance of the distal myotendinous junction A torn platarus tendon may also be identified. MR Imaging High T2 signal fluid deep to medial gastrocnemius and superficial to the soleus (Fig 6,8) Focal area of disruption of muscle continuity noted along the deep aspect of the medial head of the gastrocnemius (Fig 9), with associated oedema of the muscle (Fig 7) Plantaris tendon may be identified either torn or intact (Fig 10). Differential diagnosis A painful calf is a common clinical problem. Other causes include Page 5 of 18
- ruptured Baker cyst (Fig 12) - deep venous thrombosis - pyomyositis/abscess (Fig 13) - compartment syndrome - tumour, etc. Images for this section: Fig. 2: Ultrasound image longitudinal section through the calf region showing haematoma(star) between the medial head of gastrocnemius and soleus muscles. Partial tear of the medial head of gastrocnemius at the myotendinous junction (arrow) Page 6 of 18
Fig. 3: Another patient ultrasound image longitudinal section through the calf region showing chronic haematoma (star) between the medial head of gastrocnemius and soleus muscles. Partial tear of the medial head of gastrocnemius at the myotendinous junction (arrow). Page 7 of 18
Fig. 4: Ultrasound longitudinal section. Another case of partial tear of the medial head of gastrocnemius at the myotendinous junction with adjacent haematoma (arrow). Page 8 of 18
Fig. 5: Ultrasound image longitudinal section through the calf region showing collection(star) between the medial head of gastrocnemius and soleus muscles due to plantaris tendon rupture. Normal medial head of gastrocnemius. Page 9 of 18
Fig. 6: T1 axial image showing haematoma (star) between the medial head of gastrocnemius and soleus muscles. Page 10 of 18
Fig. 7: T2FS axial image showing collection (star) between the medial head of gastrocnemius and soleus muscles. Muscle oedema is seen in the medial head of gastrocnemius (arrow) Page 11 of 18
Fig. 8: T2FS coronal image showing collection (arrow) between the medial head of gastrocnemius and soleus muscles. Page 12 of 18
Fig. 9: T2FS axial image showing tear at the myotendinous junction of medial head o fgastrocnemius (arrow). Page 13 of 18
Fig. 10: T2FS axial image showing collection (star) between the medial head of gastrocnemius and soleus muscles. Unruptured plantaris tendon is seen (arrow) Page 14 of 18
Fig. 11: T1 axial image showing chronic haematoma (arrow) between the medial head of gastrocnemius and soleus muscles. Page 15 of 18
Fig. 12: PDFS sagittal image showing ruptured Bakers cyst (star). Fluid is tracking in the intermuscular plane. Page 16 of 18
Fig. 13: T1FS post contrast image showing abscess (star) with peripheral enhancement between the medial head of gastrocnemius and soleus. Subcutaneous inflammatory changes are also seen. Page 17 of 18
Conclusion Ultrasound is cheap and easily available imaging modality for tennis leg. It is used to diagnose tennis leg and to rule out other causes of calf pain. MRI provides a global and extensive view of injuries. Injuries of other adjacent muscles that are not commonly detected with ultrasound are also easily identified with an MRI Personal information References 1)Delgado GJ, Chung CB. Tennis leg: clinical US study of 141 patients and anatomic investigation of four cadavers with MR imaging and US. Radiology. 2002;224 (1): 112-9. 2)Jamadar DA, Jacobson JA, Theisen SE et-al. Sonography of the painful calf: differential considerations. AJR Am J Roentgenol. 2002;179 (3): 709-16. 3)Helms CA, Fritz RC, Garvin GJ. Plantaris muscle injury: evaluation with MR imaging. Radiology 1995; 195:201-203. 4)Bencardino JT, Rosenberg ZS, Brown RR, Hassankhani A, Lustrin ES, Beltran J. Traumatic musculotendinous injuries of the knee: diagnosis with MR imaging. RadioGraphics 2000; 20:103-120. Page 18 of 18