Complete rupture of the distal biceps tendon is a relatively rare event. In 96% of the cases, the common biceps tendon rupture occurs in the long head, with only 3% occurring in the distal and 1% occurring in the short heads, respectively.3,9,13 Partial ruptures of the distal biceps tendon are an even rarer event. Only 16 cases have been described.5,10-12,23,24 Although a complete rupture of the distal biceps tendon is clinically impressive and easy to diagnose,21 a partial rupture of the distal biceps tendon, especially when it is attributable to a slowly developing inflammatory condition, may cause diagnostic problems. Progressive soft tissue swelling in the proximal ventral aspect of the lower forearm in three of the four patients in the current study caused the referring physicians to suspect a soft tissue tumor.
An 82-year-old woman reported pain and a soft tissue swelling in the left antecubital fossa. Three months before admission, the patient noticed swelling that developed rapidly during the next few days, with little progression thereafter. She did not have a history of trauma. She was admitted to the authors' institution with a suspicion of soft tissue sarcoma.
On physical examination, a soft tissue swelling in the antecubital fossa was seen. There was no significant impairment in extension and strength of flexion and supination when compared with the contralateral side, but she experienced pain during supination against resistance.
Plain radiographs showed no pathologic findings. Because the patient had a cardiac pacemaker, a magnetic resonance imaging (MRI) scan was not performed. Computed tomography (CT) showed a 5 × 2.5 cm bursa extending along the undisrupted, but thinned, distal biceps tendon with calcifications present (Fig 1). Vessels and nerves were dislocated but not involved by the mass. A significant contrast enhancement typical for synovitis also could be observed. Because there was no impairment, no additional treatment was provided. The soft tissue swelling disappeared after 6 weeks, and the patient is free of symptoms 1 year after the initial diagnosis.
A 45-year-old man reported progressive pain and swelling in the left antecubital fossa for 5 weeks that was not associated with a traumatic event. The pain first was observed while the patient was performing his job as a warehouse worker but progressed to pain during the night. Two weeks after onset of symptoms, temporary numbness of his second, third, and fourth fingers developed.
Physical examination showed a firm tender 4 × 5 cm painful swelling at the volar proximal forearm close to the insertion of the biceps tendon. Active range of motion (ROM) in flexion and supination was limited by pain, and a significant impairment of strength in comparison to the contralateral side was seen. Diagnosis on admission was suspicion of a soft tissue sarcoma.
Plain radiographs showed soft tissue swelling without any bone or joint alteration. Magnetic resonance imaging showed a 6.5 × 4.5 cm partial cystic lesion along the biceps tendon semicircularly extending around the radius to the insertion of the tendon (Fig 2A-B). At this point an osseous edema was visible (Fig 2C). The lesion showed a high uptake of contrast medium, typical for synovitis.
The first diagnosis was synovitis of the distal biceps tendon with the development of a bursa, which because of its close location to the median nerve, explains the temporary irritation of that nerve. The patient was treated conservatively by immobilizing the elbow and forearm with a cast. Two months later, an MRI scan showed shrinkage of the lesion to 4.5 × 3.5 cm. The neurologic impairment had disappeared. However, because of the patient's continued pain and limitation of strength and active motion, open exploration through an antecubital S-shaped incision was performed.
The distal biceps tendon was ruptured, leaving only a few fibers attached to the radius. The stump of the tendon was engulfed in a bursalike cystic lesion well delineated from the surrounding uninvolved structures (Fig 2D). The bursa was filled with synovial tissue (Fig 2E). The biceps tendon was debrided and reinserted transosseously by augmentation with nonresorbable sutures. Histologic examination excluded neoplastic disease. Cast immobilization was resumed for 6 more weeks. Four months after surgery the patient resumed work without any limitations.
A 40-year-old man reported progressive pain in the right proximal volar forearm for 7 months before presentation; there was no history of trauma. His pain especially was pronounced in supination and flexion against resistance. Pronation was pain free with complete ROM. Clinical examination revealed a definite, asymmetric, painful tenderness at the insertion of the biceps tendon.
With MRI, a partial rupture of the distal biceps tendon with concomitant edema of the proximal radius at the tendon insertion was observed (Fig 3). A significant synovitis could not be seen.
After injection of a local anesthetic and physiotherapy, which included intermittent cooling with ice packs, transverse friction massage, and postisometric relaxation,18 the symptoms improved. Treatment was terminated 3 months after diagnosis. Nine months later, the patient reported having occasional tenderness in the antecubital fossa that did not require treatment and caused no restrictions in activities.
A 67-year-old woman reported pain in the proximal forearm for 18 months before presentation. For the last 3 months, she noticed swelling of the antecubital fossa. Clinical examination confirmed swelling and tenderness at the insertion of the distal biceps tendon. She had no pain, even with applied pressure. Rotation and strength of the forearm and flexion of the elbow were unimpaired.
Magnetic resonance imaging and CT scans showed the typical findings of a partial rupture of the distal biceps tendon with a synovial bursitis (Fig 4). Two weeks after treatment was implemented, which included a plaster splint and diclofenac, the symptoms decreased. After 4 weeks of physiotherapy, the swelling and tenderness had disappeared.
The average age of two women and two men was 59 years (range, 40-82 years). In all four cases, a common clinical pattern emerged. The main symptom was pain at the insertion of the distal biceps tendon in the radius for 1 to 18 months that was unrelated to trauma, resulting in a decrease of active flexion and supination. In three of the four patients, the partial rupture of the tendon caused a significant bursalike lesion. In one patient, the lesion was filled with histologically proven synovitis. In two patients, MRI findings confirmed the presence of a synovial bursitis. In the first case, changes typical for synovitis were seen on CT scans. In the third case, contrast enhancement on MRI of the distal tendon and edema of the insertion in the bone showed the first signs of a beginning synovitis. In all patients, the diagnosis was based on contrast enhancement, which showed the typical appearance of an altered, partially ruptured biceps tendon of varying degrees of degeneration, tenosynovitis, and soft tissue swelling extending along the tendon semicircular to the proximal radius.
In three patients, nonoperative treatment was successful. Additional imaging was not performed. Only one patient needed surgical treatment to resume physical labor in his job as a warehouse worker.
The rupture of the distal biceps tendon usually is linked to a traumatic event. Degenerative changes may contribute to impairment of tendon strength.4,7,14 Calcific tendinitis was described in this location.22 In a more recent anatomic study, a hypovascular zone in the middle of the tendon with mechanical impingement during rotation of the forearm were reported.25 The average age in five male patients and one female patient described with partial distal biceps tendon ruptures in the orthopaedic literature is 51 years (range, 38-62 years), which corresponds to this degenerative theory.5,12,23,24
Partial rupture of the tendon is an indicator of tendon alteration.5 Traumatic events were described in the history of the six previously published cases, but not in the patients in the current study.5,12,23,24 The patients in the current study presented with pain in the antecubital fossa in the early stages, followed by synovial swelling. Strength of flexion and forearm supination was not reduced considerably but occasionally was impaired by pain. In another study, a cubital bursitis attributable to repetitive minor mechanical trauma developed,15 and cubital bursitis may be the leading symptom because it was in the first patient in the current study. Depending on the size of the bursa, the close proximity to the median nerve in the cubital fossa may result in compression, as shown in Case 2 and as described in the literature.12
In the authors' experience, CT and MRI are capable of showing the extent of the lesions. Sonographic detection of tendon diseases also may be feasible but appears to be inferior in detecting the subtle changes in a partial tendon rupture.20 Magnetic resonance imaging not only shows the extent of the rupture but also detects tenosynovitis, bursa lesions, and radial edema at the insertion of the tendon as an early sign of disease.10,11 Comparing MRI and surgical findings, the distance between the distal end of the tendon seen on MRI scans and the tuberosity in subtotal ruptures has been considered a discriminating factor of partial or total tendon tear.17 In two cases, CT scans were obtained. Using contrast enhancement as shown in Figure 1, tenosynovial alterations also may be detected, although sensitivity seems to be lower with CT than with MRI.
There are numerous reports with respect to therapy and prognosis of total distal biceps tendon ruptures, providing sufficient evidence of the superiority of surgical treatment.1,2,6,8,9,16,19,21 All six patients with partial distal biceps tendon rupture reported previously were treated surgically, five because of ongoing impairment of muscle strength, and one because of compression of the median nerve. In the experience of the current authors, only one patient had inadequate relief of symptoms with conservative treatment and needed surgical treatment. Early MRI in patients with the reported symptoms may result in a significantly higher incidence of partial distal biceps tendon ruptures.
These cases show the typical clinical symptoms of partial atraumatic distal biceps tendon tears. Pain and swelling in the proximal volar forearm region should raise the suspicion of distal biceps tendon lesions, although strength of flexion and supination might not be impaired. Magnetic resonance imaging was shown to be a sensitive imaging method. Conservative treatment in early cases of partial tendon ruptures or in patients not depending on forearm strength for professional activity was successful. Depending on the symptoms, a plaster cast was used for 2 weeks, followed by intermittent cooling, transverse friction massage, and postisometric relaxation. In addition, nonsteroidal anti-inflammatory drugs were given. Surgical revision is recommended in patients with total tendon tears or in those depending on unimpaired function of the forearm.
1. Agins HJ, Chess JL, Hoekstra DV, Teitge RA: Rupture of the distal insertion of the biceps brachii tendon. Clin Orthop 234:34-38, 1988.
2. Baker BE, Bierwagen D: Rupture of the distal tendon of the biceps brachii. Operative versus non-operative treatment. J Bone Joint Surg 67A:414-417, 1985.
3. Baumann BS: Rupture of the biceps tendon. J Bone Joint Surg 44A:741-747, 1961.
4. Bindl G, Egner E, Holz U: [Rupture of the distal biceps tendon]. Die Ruptur der distalen Bizepssehne. Unfallchirurgie 14:259-264, 1988.
5. Bourne MH, Morrey BF: Partial rupture of the distal biceps tendon. Clin Orthop 271:143-148, 1991.
6. D'Arco P, Sitler M, Kelly J, et al: Clinical, functional, and radiographic assessments of the conventional and modified Boyd-Anderson surgical procedures for repair of distal biceps tendon ruptures. Am J Sports Med 26:254-261, 1998.
7. Davis WM, Yassine Z: An etiologic factor in the tear of the distal tendon of the biceps brachii. J Bone Joint Surg 38A:1365-1368, 1956.
8. Davison BL, Engber WD, Tigert LJ: Long term evaluation of repaired distal biceps brachii tendon ruptures. Clin Orthop 333:186-191, 1996.
9. Dobbie RP: Avulsion of the lower biceps brachii tendon: Analysis of fifty-one previously reported cases. Am J Surg 51:662-683, 1941.
10. Falchook FS, Zlatkin MB, Erbacher GE, et al: Rupture of the distal biceps tendon: Evaluation with MR imaging. Radiology 190:659-663, 1994.
11. Fitzgerald SW, Curry DR, Erickson SJ, Quinn SF, Friedman H: Distal biceps tendon injury: MR imaging diagnosis. Radiology 191:203-206, 1994.
12. Foxworthy M, Kinninmonth AW: Median nerve compression in the proximal forearm as a complication of partial rupture of the distal biceps brachii tendon. J Hand Surg 17B:515-517, 1992.
13. Gilcreest EL: Dislocation and elongation of the long head of the biceps brachii. Ann Surg 104:118-138, 1936.
14. Hovelius L, Josefsson G: Rupture of the distal biceps tendon. Report of five cases. Acta Orthop Scand 48:280-282, 1977.
15. Karanjia ND, Stiles PJ: Cubital bursitis. J Bone Joint Surg 70B:832-833, 1988.
16. Krüger-Franke M, Theermann R, Refior HJ: [Rupture of the distal tendon of the biceps-diagnosis and results]. Die distale Bizepssehnenruptur-Diagnostik, Therapie und Ergebnisse. Z Orthop Ihre Grenzgeb 130:31-35, 1992.
17. Le Huec JC, Moinard M, Liquois F, et al: Distal rupture of the tendon of biceps brachii. Evaluation by MRI and the results of repair. J Bone Joint Surg 78B:767-770, 1996.
18. Lewit K, Simons DG: Myofascial pain: Relief by post-isometric relaxation. Arch Phys Med Rehabil 65:452-456, 1984.
19. Lintner S, Fischer T: Repair of the distal biceps tendon using suture anchors and an anterior approach. Clin Orthop 322:116-119, 1996.
20. Lozano V, Alonso P: Sonographic detection of the distal biceps tendon rupture. J Ultrasound Med 14:389-391, 1995.
21. Morrey BF, Askew LJ, An KN, Dobyns JH: Rupture of the distal tendon of the biceps brachii. A biomechanical study. J Bone Joint Surg 67A:418-421, 1985.
22. Murase T, Tsuyuguchi Y, Hidaka N, Doi T: Calcific tendinitis at the biceps insertion causing rotatory limitation of the forearm: A case report. J Hand Surg 19A:266-268, 1994.
23. Nielsen K: Partial rupture of the distal biceps brachii tendon. A case report. Acta Orthop Scand 58:287-288, 1987.
24. Rokito AS, McLaughlin JA, Gallagher MA, Zuckerman JD: Partial rupture of the distal biceps tendon. J Shoulder Elbow Surg 5:73-75, 1996.
25. Seiler III JG, Parker LM, Chamberland PD, Sherbourne GM, Carpenter WA: The distal biceps tendon. Two potential mechanisms involved in its rupture: Arterial supply and mechanical impingement. J Shoulder Elbow Surg 4:149-156, 1995.