Journal of Medical Ultrasound (2011) 19,91e94

Available online at www.sciencedirect.com

journal homepage: www.jmu-online.com

CASE REPORT Common Flexor Tear Following Yoga and Local Corticosteroid Injections: A Case Report

Tian-Shin Yeh, Ke-Vin Chang*, Tyng-Guey Wang

Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan

Received May 24, 2010; accepted September 20, 2010 Available online September 29, 2011

KEY WORDS Severe tearing of the around the is rare, even in athletes; especially tearing of , the common flexor tendon of the wrist. We report the case of a 52-year-old housewife who sport, complained of bilateral medial elbow pain after forcefully extending her wrist and elbow while tendon practicing yoga. Repeated corticosteroid injections were administered over her right medial elbow at an orthopedic clinic. Her pain was relieved temporarily but recurred later. She visited our rehabilitation outpatient department, and physical examination revealed weakness during right wrist flexion and pronation. Hence, sonography was performed, which showed a hypoechoic area and soft tissue indentation within the right common flexor tendon. Subse- quent magnetic resonance imaging revealed a focal area with a hyperintense signal around the medial epicondyle on fast short-inversion-time inversion recovery images. Both imaging studies indicated a complete tear of the common flexor tendon, and surgical exploration confirmed the imaging findings. We speculated that the infrequent presentation of a medial elbow injury may be attributable to preceding valgus stress and eccentric loading of the elbow during yoga and further tendon weakening after repeated corticosteroid injections. ª 2011, Elsevier Taiwan LLC and the Chinese Taipei Society of Ultrasound in Medicine. All rights reserved.

Introduction

Tendon tear is the end result of severe degenerative ten- dinopathy and is uncommon around the elbow [1]. Rupture of the of the wrist has been re- * Correspondence to: Dr Ke-Vin Chang, Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital, ported in athletes [2]. However, there are few reports in College of Medicine, National Taiwan University, 7 Chan-Shan South the literature that describe a complete tear of the common Road, 100, Taipei, Taiwan, ROC. flexor tendon of the wrist [3,4]. In the present case report, E-mail address: [email protected] (K.-V. Chang). we describe a complete tear of the common flexor tendon

0929-6441/$36 ª 2011, Elsevier Taiwan LLC and the Chinese Taipei Society of Ultrasound in Medicine. All rights reserved. doi:10.1016/j.jmu.2011.08.004 92 T.-S. Yeh, et al. of the wrist in a 52-year-old housewife. The precipitating tenderness in the right medial epicondyle and moderate pain factors may have been excessive elbow and wrist extension on flexing her right wrist against resistance. There was no during yoga, followed by repeated corticosteroid injections swelling or local heat. Muscle power during right wrist flexion at the medial elbow. The possible mechanism and the and forearm pronation was rated grade 4 over 5. Hence, importance of imaging studies are discussed in this article. sonography was performed with a 14-MHz liner array trans- ducer (Acuson S2000 System; Siemens, Munich, Germany). The sonogram showed a hypoechoic lesion through the full Case report width of the common flexor tendon and indentation of the above soft tissue (Fig. 2A). A tear in the common flexor tendon A 52-year-old right-handed housewife had complained of of the wrist was suspected. She was referred to our ortho- bilateral medial elbow pain since 2005. She had attended pedic outpatient department. Preoperative magnetic reso- > yoga classes four times per week for 10 years. At the nance imaging (MRI) revealed a mildly increased signal on T1- beginning of 2005, she first experienced bilateral medial weighted images at the insertion of the common flexor elbow pain when she attempted to perform certain actions tendon (Fig. 3A). By contrast, an intense fluid-like intra- involving vigorous wrist and elbow extension. The yoga tendon signal was noted at the same site on a fast short- posture is shown in Fig. 1: a quadrupedal position with inversion-time inversion recovery (STIR) image in the approximated knees and forceful extension of the elbows coronal planes (Fig. 3B). A focal hyperintense lesion was and wrists. It was emphasized that the body weight should observed adjacent to the medial epicondyle on a fast STIR mainly be placed on the upper extremities. She had to image in the axial planes (Fig. 3C and 3D). Both imaging maintain this pose for about 5 minutes in one set of exer- studies indicated complete tear of the common flexor cises and approximately six to seven sets were performed tendon. Surgical exploration confirmed complete tendon tear per class. After 6 months of practice, the pain in her elbow distal to the insertion in addition to fibrous scarring. The became worse, especially on the right side. She barely managed to lift heavy objects and was hardly capable of tolerating the elbow and wrist extension when brushing the floor in the quadrupedal posture. As a result of severe elbow discomfort, the patient visited orthopedic clinics where she was diagnosed with medial epicondylitis. A corticosteroid injection was administered to her right medial elbow twice within 2 months. She kept practicing yoga, and her elbow pain recurred after she started attending the class. In 2006, she decided to dis- continue yoga. She then underwent acupuncture and phys- ical therapy, including massage and transcutaneous electrical stimulation, at several local clinics in the following years. However, the pain in her elbow persisted, and her right was incapable of having a powerful grip. She came to our rehabilitation outpatient department on June 25, 2009. Physical examinations demonstrated local

Fig. 2 (A) A hypoechoic area with a thickness of 4.3 mm (Distance B) was observed distal to the insertion of the right common flexor tendon. There was soft tissue indentation above the hypoechoic lesion. The thickness of the tendon measured proximal to the elbow joint was 4.4 mm (Distance A). Fig. 1 Posture during yoga was demonstrated by one of our (B) Compared with the right common flexor tendon, the authors (T.S. Yeh). It consisted of a quadrupedal posture, fibrillary arrangement was relatively intact without disruption approximated knees and forceful extension of elbows and in the left common flexor tendon. The thickness of the tendon wrists. Placing the body weight mostly on her upper extremi- measured proximal to the elbow joint was 3.3 mm, which was ties was emphasized. thinner than the right side (Distance A). Common Flexor Tendon Tear 93

Fig. 3 (A) MRI revealed a mildly increased signal in T1-weighted images at the insertion of the common flexor tendon in the coronal plane (arrow). (B) By contrast, a more intense intratendon signal was noted at the same site in the fast short-inversion-time inversion recovery (STIR) image in the coronal plane (arrow). (C and D) Focal hyperintense lesion was clearly observed adjacent to the medial epicondyle in fast STIR image in the axial planes (arrow). tendon was then repaired with suture anchors. During requiring high valgus force. However, in the present case, a routine visit at 3 months after the operation, it was reported the patient was a housewife and was unlikely to undertake that the pain had significantly reduced and the strength of the excessive valgus loading at the elbow. Hence, it was difficult right wrist flexion and forearm pronation gradually improved. to anticipate such a severe tear before sonography. Extreme valgus torque at the medial elbow and increased eccentric loading on the common flexor tendon Discussion during yoga may have led to tendinopathy in the common flexor tendon. Although yoga has been proven to be bene- The common flexor tendon originates from the medial elbow ficial for physical fitness and cardiovascular endurance [8], and consists of pronator teres, flexor carpi radialis, palmaris it may involve movements beyond the normal range of joint longus, flexor digitorum superficialis, and flexor carpi ulnaris motion. Overstretching of the muscle tendon complex [5]. Degenerative enthesopathy of the common flexor is commonly observed in unskilled practitioners. Usual tendon is far less common than that of the extensor side. motions of the upper extremities, such as wrist flexion and Prevalence of lateral epicondylitis is 1.3%, whereas that of pronation, require concentric force on the common flexor the medial epicondylitis is 0.4% [6]. The primary etiology of tendon. However, forceful extension of the elbow and wrist epicondylitis is repetitive stress or overuse, or it may also during yoga causes extreme eccentric loading on the stem from sudden eccentric loading [7]. Both the common common flexor tendon, which in turn increases tensile flexor and extensor tendons are conjoined tendons with high force on the tendon as compared to that during concentric strength that is resistant to tensile force, therefore, contraction [9], thereby putting the already vulnerable a complete tear is rare, especially at the flexor site. It is common flexor tendon at a greater risk of tendinopathy. reasonable to expect that a tear of the common flexor Administration of the corticosteroid injection to the tendon occurs in athletes who participate in exercises patient’s medial elbow was the critical point that led to 94 T.-S. Yeh, et al. tendon tear in her elbow. A prospective, single-blind study with tears or tears filled with granulation tissue [4]. This is has shown that local steroid injection provides short-term supported by a study correlating the MRI findings of a case of relief from pain due to medial epicondylitis [10], but this chronic epicondylitis with the histopathological findings from may also lead to complications, including infection and surgical specimens [15]. In the present case, the focal tendon rupture. Although the literature does not describe hyperintense lesion adjacent to the medial epicondyle on steroid-related common flexor tendon tear, ruptures at fast STIR images favored the diagnosis of a common flexor uncommon sites, such as the peroneus longus tendon, have tendon tear (Fig. 3). The following surgical exploration been reported after steroid injection [11]. The appropriate confirmed the tentative diagnosis from both imaging studies. technique for administering an injection requires instilling Besides, the scarring tissues at the insertion of the common the corticosteroid into the fatty subaponeurotic recess flexor tendon seemed to be attributable to the chronic deep into the [5]. Injection into soft course that our patient encountered. tissues results in soft tissue atrophy, and injection into the In conclusion, complete tear of the common flexor tendons causes collagen degeneration, allowing a traction tendon is rare among the non-athletic population. In the injury to occur at the myotendinous junction [2]. According present case, excessive eccentric loading from yoga and to the guidelines recommended for the administration of administration of corticosteroid injections placed the a local corticosteroid injection, the minimum interval tendon at risk. It is difficult to differentiate between severe between injections should be 6 months and a maximum of medial epicondylitis and a common flexor tendon tear three injections is allowed at one site [12]. Our patient merely through clinical presentations. However, surgical received multiple corticosteroid injections at shorter repair is needed to restore muscle function in the forearm intervals. This produced a deleterious effect in the patient in patients with a common flexor tendon tear. Hence, and as a result, her tendon was unable to resist tensile ultrasonography or MRI is strongly suggested in patients strength from the wrist and elbow extension. with long standing medial epicondylitis. The use of ultrasonography helped us to make the correct diagnosis. Although weakness during wrist flexion and References forearm pronation made us consider the possibility of a tendon tear, we considered that this weakness could also [1] Rineer CA, Ruch DS. Elbow tendinopathy and tendon ruptures: result from severe pain due to inflammatory tendinopathy. epicondylitis, and ruptures. J Hand Surg Am In addition to the severity of tendinopathy, ultrasonography 2009;34:566e76. provides additional information, including calcification, [2] Smith AG, Kosygan K, Williams H, et al. Common extensor increased vascularity, and the extent of tendon tear [13]. tendon rupture following corticosteroid injection for lateral The sensitivity and specificity of the ultrasonography have tendinosis of the elbow. Br J Sports Med 1999;33:423e5. been reported as up to 95.2% and 92%, respectively, for [3] Park GY, Lee SM, Lee MY. Diagnostic value of ultrasonography medial epicondylitis [3]. Park et al have classified the for clinical medial epicondylitis. Arch Phys Med Rehabil 2008; common flexor tendon pathology as tendinosis, partial- 89:738e42. thickness tear, or full-thickness tear. In their study, none [4] Martin CE, Schweitzer ME. MR imaging of epicondylitis. Skel- e of the 21 elbows of 43 patients who were examined had etal Radiol 1998;27:133 8. [5] Ciccotti MG, Ramani MN. Medial epicondylitis. Tech Hand Up a full-thickness tear [3]. This indicated that a complete tear Extrem Surg 2003;7:190e6. of the common flexor tendon of the wrist is a rare finding [6] Shiri R, Viikari-Juntura E, Varonen H, et al. Prevalence and during ultrasound examination for medial elbow pain. determinants of lateral and medial epicondylitis: a population In the present case, a distinct complete interval study. Am J Epidemiol 2006;164:1065e74. extending through the full width was noted distal to the [7] Leach RE, Miller JK. Lateral and medial epicondylitis of the insertion of the right common flexor tendon (Fig. 2). The elbow. Clin Sports Med 1987;6:259e72. finding fulfilled the criteria of a full-thickness tendon tear. [8] Pullen PR, Nagamia SH, Mehta PK, et al. Effects of yoga on Indentation of the soft tissue above the hypoechoic area inflammation and exercise capacity in patients with chronic was also noted (Fig. 2). The additional findings repre- heart failure. J Card Fail 2008;14:407e13. sented significant intrasubstance loss, and massive tendon [9] Komi PV. Physiological and biomechanical correlates of muscle function: effects of muscle structure and stretch-shortening tear should be considered. A previous study has also re- cycle on force and speed. Exerc Sport Sci Rev 1984;12:81e121. ported cortical irregularity and spur formation accompa- [10] Stahl S, Kaufman T. The efficacy of an injection of steroids for nied by a partial-thickness tear of the tendons at the medial epicondylitis. A prospective study of sixty elbows. J medial elbow [3]. However, we did not observe both Bone Joint Surg Am 1997;79:1648e52. findings in our case. Besides, the increased tendon thick- [11] Borland S, Jung S, Hugh IA. Complete rupture of the peroneus ness at the proximal part of the right side tendon as longus tendon secondary to injection. Foot (Edinb) 2009;19: compared with the left side may be indicative of pre- 229e31. existing tendinopathy. As compared to the right common [12] Speed CA. Fortnightly review: corticosteroid injections in flexor tendon, the fibrillary arrangement was relatively tendon lesions. BMJ 2001;323:382e6. intact without disruption on the left side. [13] Tran N, Chow K. Ultrasonography of the elbow. Semin Mus- culoskelet Radiol 2007;11:105e16. The MRI findings agreed with those of ultrasonography [14] Kijowski R, De Smet AA. Magnetic resonance imaging findings and provided more anatomical details before surgical in patients with medial epicondylitis. Skeletal Radiol 2005;34: exploration. Increased T1 and T2 signal intensity of the 196e202. common flexor tendon and the presence of soft tissue edema [15] Potter HG, Hannafin JA, Morwessel RM, et al. Lateral epi- are the hallmark of medial epicondylitis [14]. Nevertheless, condylitis: correlation of MR imaging, surgical, and histo- an intense fluid-like intratendon T2 signal is associated only pathologic findings. Radiology 1995;196:43e6.