SurgicalManagement of Acute Distal Biceps Tendon

785 C OPYRIGHT Ó 2017

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T HE J OURNAL

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S URGERY, I NCORPORATED

Current Concepts Review

Surgical Management of Acute Distal Biceps Tendon Ruptures David D. Savin, MD, Jonathan Watson, MD, Ari R. Youderian, MD, Simon Lee, MD, MPH, Jon E. Hammarstedt, BS, Mark R. Hutchinson, MD, and Benjamin A. Goldberg, MD Investigation performed at the University of Illinois at Chicago, Chicago, Illinois

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Acute distal biceps tendon ruptures are uncommon injuries that often affect young active males and typically result from an eccentric load on the dominant upper extremity.

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Surgical treatment may be indicated to prevent substantial weakness in supination and flexion that can occur with nonoperative treatment.

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Nonoperative management should be reserved for elderly or less active patients with multiple comorbidities, especially when the injury involves the nondominant arm.

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Operative management can be performed using a single-incision or dual-incision technique, with multiple surgical options for tendon-to-bone fixation.

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Single-incision repair techniques are more likely to be complicated by a transient neurapraxia, most often involving the lateral antebrachial cutaneous nerve, while dual-incision repair techniques are more likely to be complicated by heterotopic ossification and stiffness.

Peer Review: This article was reviewed by the Editor-in-Chief and one Deputy Editor, and it underwent blinded review by two or more outside experts. The Deputy Editor reviewed each revision of the article, and it underwent a final review by the Editor-in-Chief prior to publication. Final corrections and clarifications occurred during one or more exchanges between the author(s) and copyeditors.

Acute distal biceps tendon ruptures are uncommon injuries that affect young active males, typically resulting from an eccentric load on the dominant upper extremity. These injuries have been reported to involve the dominant extremity in 86% of patients, with an overall incidence of 1.2 ruptures per 100,000 patients per year1. Mechanism of Injury and Risk Factors These injuries typically result from an acute eccentric load on a flexed elbow1. This load results in the avulsion of the biceps tendon from the bicipital tuberosity. The bicipital aponeurosis may or may not rupture. There is an increased rate of distal biceps ruptures in athletes, particularly those who participate in contact sports and high-load resistance training programs2.

The injured tendon often has some preexisting tendinosis, or mucoid degeneration, making the structure more vulnerable to rupture3. Mechanical impingement in the radioulnar space on the biceps tendon during forearm rotation in the presence of decreased vascularity may also be a contributing factor4. Smoking contributes up to a 7.5-fold greater risk of injury compared with nonsmoking1. Furthermore, the use of anabolic steroids may increase tendon stiffness combined with increased biceps muscle strength, which may increase the risk for a rupture5. Anatomy and Biomechanics Biceps Brachii Muscle The biceps brachii muscle is a spindle-shaped muscle located in the anterior compartment of the arm consisting of 2 bellies, the

Disclosure: No external funding was received for this work. The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article (http://links.lww.com/JBJS/C820).

J Bone Joint Surg Am. 2017;99:785-96

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http://dx.doi.org/10.2106/JBJS.17.00080

786 TH E JO U R NA L O F B O N E & JO I N T SU RG E RY J B J S . O RG V O LU M E 99 -A N U M B E R 9 M AY 3, 2 017 d

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long head and the short head. The 2 heads of the biceps merge at the level of the deltoid tuberosity. The distal insertion of the biceps brachii is the bicipital tuberosity of the proximal aspect of the radius, and the mean tendon length is 57 mm6. Tendon width measured in cadavers was found to average approximately 5.3 mm (range, 3.6 to 9 mm) at the level of the bicipital aponeurosis7. Although originally thought to be a single tendon insertion, bifurcated distal biceps brachii tendons are evident, and isolated ruptures of a single tendon in a bifurcated tendon have been reported7-12. A bifid bicipital tuberosity with a distinct ridge was seen in 6% of 178 cadaver specimens13. The long head of the tendon travels deep to the short head of the tendon and inserts more proximally on the tuberosity. The short head of the tendon inserts more distally and commonly covers the apex of the tuberosity. At the musculotendinous junction, the biceps tendon begins in the coronal plane and gradually externally rotates 90° as it approaches the tuberosity, resulting in a more distal insertion of the short head compared with the long head8-10. Bicipital Tuberosity of the Radius Forearm supination biomechanics are substantially influenced by the location and orientation of the distal biceps tendon footprint14. Substantial variation of the footprint anatomy exists, with the proximal to distal length ranging from 13.8 to 30 mm and the width ranging from 3.6 to 19 mm10,13,15. The mean distance between the most proximal end of the footprint and the articular margin of the radial head has been reported to be 23 mm10. On average, the total area of the footprint was 108 mm2, according to Athwal et al.10. On average, the distal biceps tendon inserts approximately 24° ulnar to the apex, incorporating the apex as a cam and creating a pulley-type mechanism that increases the mechanical advantage of the tendon13,16,17. The footprint of the short head typically encompasses the apex of the bicipital tuberosity and occupies a greater area compared with the long head, whose footprint is located more posteriorly8-10. With this orientation, the short head is a stronger elbow flexor and produces a higher supinating moment arm with the forearm in neutral and pronated positions8. The more posteriorly located long head creates a substantially greater supination moment arm while the arm is in 60° of supination14. Footprint anatomy is shown in Figure 1. Bicipital Aponeurosis The bicipital aponeurosis, or lacertus fibrosus, is a broad fascial band that serves to separate the superficial and deep structures within the cubital fossa. It originates from the distal biceps tendon approximately 34.9 mm cephalad to the proximal radial insertion, subsequently encircling the ulnar flexors before inserting onto the ulna10. The aponeurosis maintains an intimate connection to the antebrachial fascia and crosses the midline of the arm superficial to the brachial artery and the median nerve9. There are 3 anatomic layers that merge and form the single aponeurosis that continues distally9. Biomechanically, the aponeurosis functions to direct the biceps tendon pull vector toward the radius while carrying the biceps flexion force to the ulna6,9.

Fig. 1

Coronal view of the elbow demonstrating the neurovascular anatomy. BT = biceps tendon, LHA = long head of the biceps tendon attachment, SHA = short head of the biceps tendon attachment, R = radius, U = ulna, H = humerus, B = brachioradialis, BA = brachial artery, MN = median nerve, LABCN = lateral antebrachial cutaneous nerve, RRA = recurrent radial artery, RN = radial nerve, BECRL = branch to the extensor carpi radialis longus, BECRB = branch to the extensor carpi radialis brevis, DBRN = deep branch of the radial nerve, and SFBR = superficial branch of the radial nerve.

Neurovascular Structures Three zones of vascularity have been described in relation to the distal biceps tendon4. The proximal zone encompasses the musculotendinous junction and proximal portion of the tendon, where branches of the brachial artery extend across and continue within the tendon paratenon. Branches originating from the posterior interosseous recurrent artery supply the distal zone at the biceps tendon enthesis on the bicipital tuberosity4. The middle zone is a hypovascular zone, averaging 21.4 mm in length, which is supplied by branches from both of these major arteries, but only through a thinner paratenon covering4. Seiler et al. hypothesized that the relatively limited vascular supply of the middle zone may contribute to a diminished ability to support tendon repair and the zone may be prone to secondary rupture and injury4. When the volar approach is used, the lateral antebrachial cutaneous nerve (LABCN) is at risk for injury. It is a terminal branch of the musculocutaneous nerve and has been shown to consistently emerge near the lateral aspect of the


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Fig. 2

Figs. 2-A and 2-B Preoperative and postoperative clinical photographs of a patient with an acute distal biceps rupture. The reverse “Popeye deformity” (asterisk) (Fig. 2-A) was corrected with surgical repair (Fig. 2-B).

distal biceps tendon, usually traveling with the cephalic vein. This nerve bifurcates into a volar branch, supplying the lateral volar portion of the wrist skin and portions of the thumb, and a dorsal branch, supplying the distal two-thirds of the dorsolateral forearm skin. The posterior interosseous nerve (PIN) is a purely motor structure and is the continuation of the deep branch of the radial nerve. It is at risk during exposure, retracting, and drilling. Hackl et al. described how the PIN courses 10 mm proximal to the bicipital tuberosity in supination and 5 mm distal to it in pronation during the anterior approach18. The neurovascular anatomy is shown in Figure 1.

History, Examination, and Imaging Patients often present with injury resulting from an eccentric load or carrying a heavy object. It is common for patients to report an audible “pop,” with associated ecchymosis and weakness. It is important to obtain a thorough history, including smoking status, use of anabolic steroids, preinjury pain, and a recent increase in physical activity. A full assessment of the injured arm and comparison with the contralateral extremity should be performed. It is important to rule out any neurologic deficits that may lead to elbow flexion weakness. Patients may present with a proximal biceps bulge from muscle retractions and ecchymosis (Fig. 2),

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Figs. 3-A and 3-B Demonstration of the hook test . Fig. 3-A The test should be performed with the elbow flexed to 90° and the arm in full supination. The examiner uses his or her finger to capture the lateral edge of the biceps tendon. Fig. 3-B Note the lack of the intact biceps tendon and the inability to “hook” the biceps tendon with the examiners’ finger. In addition, ecchymosis (arrow), with pooling in the proximal aspect of the forearm, is seen.


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which may be seen in the antecubital fossa with pooling in the anteromedial proximal forearm (Fig. 3). Patients with a distal biceps rupture will have asymmetric weakness in supination and elbow flexion. In order to isolate the biceps tendon, supination strength should be assessed with the elbow flexed to 90° and the arm in maximal supination. This isolates the biceps brachii muscle from the supinator. The hook test19 is used to evaluate the integrity of the distal biceps tendon and has been found to have high specificity and sensitivity in the evaluation of a distal biceps tendon rupture19. The test is performed with the elbow flexed to 90° with the arm in full supination. The examiner uses his or her finger to capture the lateral edge of the biceps tendon (Fig. 3). If the tendon is intact, the examiner should be able to insert the finger 1 cm underneath the tendon. Palpation of the brachialis or bicipital aponeurosis may falsely suggest an intact biceps tendon. Additional components of the examination may include abduction of the ipsilateral shoulder to 90° and comparison with the contralateral side. Abduction of the shoulder with the elbow partially flexed, although not mandatory, may help the examiner evaluate the contour of the biceps muscle and its distal insertion. Standard radiographs are often without any evidence of pathology, except for soft-tissue swelling, but occasionally show an avulsion injury to the distal biceps insertion. Magnetic resonance imaging (MRI) may be used in cases that are difficult to diagnose or to evaluate chronic injuries. The biceps muscle should be identified proximally at its muscle belly and traced distally to identify the tendon insertion (Fig. 4). A FABS (flexed elbow, abducted shoulder, and forearm supinated) view improves visualization of the insertion of the biceps tendon. Ultrasound is a good dynamic tool to evaluate continuity of the biceps tendon; however, its utility is technician-dependent. These advanced imaging modalities are helpful but merely confirmatory, as the diagnosis can be made clinically, and expeditious management should not be delayed for these imaging studies. Nonoperative Management Nonoperative management should focus on decreasing swelling, decreasing inflammation, and early range of motion using common protocols of ice, compression, and anti-inflammatory oral medications with secondary elbow strengthening. With nonoperative management, a 40% to 50% reduction in supination strength, 30% reduction in flexion strength, and 15% reduction in grip strength can be expected20. This may be tolerated in an older or less active individual, especially in the nondominant arm. A discussion with a full understanding of the patient’s activities, comorbidities, activity level, hand dominance, and surgical risk-to-benefit ratio should be performed when making a decision between operative and nonoperative management. Nonoperative management of partial ruptures may be attempted; however, Vardakas et al. reported a 100% rate of


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Fig. 4

A FABS (flexed elbow, abducted shoulder, and forearm supinated) view proton-density fat-saturated MRI demonstrating a tear of the biceps tendon.

conversion to operative management after failure of conservative management21. In a comparison of strength between patients treated nonoperatively and a historical control group treated operatively, Freeman et al. found that the mean supination and flexion strength in the involved arm compared with that in the contralateral arm was 63% and 93%, respectively, in the nonoperative group and 92% and 95% in the operatively treated group22. Both groups had satisfactory outcomes scores22. Legg et al. found that nonoperative management resulted in significant loss of supination (p = 0.004) and flexion strength (p = 0.015) and significantly worse outcomes scores (p < 0.05) compared with those who had surgical repair with an EndoButton23. Operative Management Operative management results in improved strength in flexion and supination and in increased upper extremity endurance9,20. There are multiple options regarding the approach and fixation technique. Anterior Approach The anterior approach may be used for the single-incision approach or as the anterior interval for an anterior-posterior approach. The patient should be positioned supine with an arm board attached and the involved arm draped free. We prefer the use of a sterile tourniquet. A single longitudinal incision should be made medial to the brachioradialis muscle and distal to the elbow crease for 3 to 4 cm. A single (modified Henry approach)24 or double transverse incision can be used. If double anterior incisions are used, the proximal incision is used for


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capturing the biceps tendon. This may also be performed using only the distal incision. The distal transverse incision begins 2 finger breadths distal to the elbow crease at the level of the radial tuberosity. The dissection should be carried down toward the radial tuberosity between the brachioradialis laterally and the pronator teres muscle medially. During this exposure, care should be taken to identify and protect the LABCN and the deeper recurrent branches of the radial artery. Ligation of the recurrent branch of the radial artery may help in the exposure of the tuberosity. An intact biceps tendon sheath or encapsulated hematoma may be found and can be incised longitudinally to evacuate any remaining fluid. The biceps muscle should then be retrieved. Posterior Approach A 2-incision approach (modified Boyd-Anderson)25 can be used. The anterior incision is similar to the modified Henry approach. The posterior incision should be created after completing the anterior approach. This incision is in line with the lateral epicondyle or center of the radial head, approximately 2 fingerbreadths from the ulnar crest. With the arm in maximal pronation to protect the PIN, a curved clamp should be passed from the anterior incision, medial to the radial tuberosity between the radius and ulna and then directed posteriorly. It is important to avoid damaging the periosteum on the ulna when passing between the radius and ulna in order to reduce the risk of radioulnar synostosis. The clamp is passed through the common extensor muscles and is palpated subcutaneously. A 3-cm posterior incision should be made. A muscle-splitting approach through the common extensor origin is preferred to a subperiosteal dissection and reduces the risk of synostosis. The approach should be in line with the muscle fibers. For all repairs, the distal end of the biceps and the radial tuberosity should be debrided of any bursal tissue, degenerative tendon, or fibrocartilage. Tension Slide Technique The tension slide technique (TST) was originally reported by Sethi et al.26. The biceps tendon is sutured using a locking whipstitch with 1 nonabsorbable number-2 braided polyblend suture starting approximately 0.5 cm from the distal end. With the use of a cortical button, 1 strand should be fed in 1 end and out through the other. The second strand of suture is fed back through the button in the opposite direction. With the forearm in maximal supination, a 3.2-mm guide wire is inserted through 2 cortices, starting at the center of the radial tuberosity at 30° of ulnar deviation to help to reduce the risk of a PIN injury27. With a reamer sized approximately 0.5 to 1 mm larger than the sized tendon, the radius is reamed through the near cortex. The button should then be loaded on the inserter and passed through the far cortex to the posterior aspect of the radius. Pulling on the free sutures will seat the button and dock the biceps into the radial tuberosity. Once the tendon is fully seated, 1 limb of the suture should be passed through the biceps tendon just proximal to the radial tuberosity using a free suture needle. Alternatively, one could pass the suture 1 cm proximal to the


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tendon stump prior to seating the tendon in the tunnel, which avoids passing a suture in limited deep exposure. The 2 ends of the suture are then secured using multiple knots (Fig. 5). Intraoperative imaging may be used to confirm the appropriate position of the button on the radial tuberosity. The position of the button on the posterior surface of the proximal aspect of the radius can be seen in Figure 6. Two-Incision Bone Tunnels The 2-incision technique was originally described by Boyd and Anderson25 and was modified by Morrey and colleagues to reduce radioulnar synostosis by using a muscle-splitting approach20,28. A standard, 2-incision, muscle-splitting approach is used for the double-incision bone tunnel technique (Fig. 7). The tendon is prepared using a standard locking whip-stitch. The radial tuberosity should be identified from the dorsal approach. Biceps tendon remnants are debrided. A high-speed burr should be carefully used to create a trough approximately 8 mm in width and 10 mm in length. Care must be taken to ensure the trough is