Robert E. Ivy and Edwin E. Spencer, Jr.
DEFINITION
Disruption of distal biceps tendon at its insertion
ANATOMY
Distal tendon inserts into the biceps tuberosity on the proximal radius.
A relatively avascular zone exists just proximal to the tendon’s insertion site.15
PATHOGENESIS
Injury typically results from an eccentric muscle contraction. The forearm is forced into extension from a flexed position as the biceps muscle fires
Avascular changes in the distal tendon and possible impingement in the interosseous space between the tuberosity and the proximal ulna may contribute to rupture.15
NATURAL HISTORY
Complete ruptures
Distal biceps tendon ruptures usually occur in middleaged men, similar to pectoralis major tendon ruptures and Achilles tendon ruptures.
The initial pain subsides quickly but there is usually a noticeable deformity in the anterior brachium as the biceps muscle contracts and retracts. The degree of the retraction can be mitigated by the lacertus fibrosus, which may remain intact.
The patient usually reports loss of flexion and supination strength. This is especially noted in patients who require repetitive supination, such as mechanics and plumbers. Pain is usually not a predominant complaint, although some patients will experience fatigue-type pain and cramping in the retracted muscle belly.
Studies have revealed a 25% reduction in flexion strength and a 40% loss of supination strength.2,11
Partial ruptures
Partial distal biceps tendon injuries are usually more painful than complete tears. Patients usually present with pain in the antecubital fossa, especially with resisted flexion and supination. There is an absence of clinical deformity.
Partial tears can progress to complete tears.
PATIENT HISTORY AND PHYSICAL FINDINGS
History of a rapid eccentric load on the involved extremity
In acute cases of a complete distal biceps tendon rupture, there is usually a significant amount of ecchymosis in the antecubital fossa, distal arm, and proximal forearm.
The distal biceps tendon is not palpable in the antecubital fossa. Comparison to the uninvolved side is helpful.
Local edema can make the diagnosis a little more difficult, but the “hook test” has been found to be a very reliable diagnostic tool. To perform the test, the patient actively supinates the forearm while the examiner attempts to “hook” the distal biceps tendon from the lateral side.12
The degree of proximal retraction of the tendon can be mitigated by the lacertus fibrosus.
IMAGING AND OTHER DIAGNOSTIC STUDIES
MRI is usually not necessary to make the diagnosis. The only caveat is that if the examiner feels that the distal biceps tendon is intact, the injury might be more proximal at the myotendinous junction or only a partial tear at its insertion.
It is important to make the distinction between the common complete avulsion from the radial tuberosity and an injury at the myotendinous junction, as the more proximal injuries are best treated nonoperatively.14
Partial tears occur at the radial tuberosity, are usually not associated with ecchymosis, and demonstrate no proximal retraction. They present late with pain with resisted flexion and supination. The distal biceps tendon is palpable and frequently tender.
MRI can aid in the diagnosis of partial tendon ruptures.
NONOPERATIVE MANAGEMENT
Nonoperative management of complete distal biceps tendon ruptures entails the use of modalities to reduce pain and swelling and simply allowing the patient to use the extremity as tolerated. Strengthening should focus on elbow flexion and supination.
The surgeon should discuss with the patient that complete distal biceps tendon ruptures are not usually associated with residual pain but rather loss of flexion (30%) and supination (40%) strength.2,11 If that is compatible with the patient’s job and lifestyle, nonoperative management is acceptable.
Partial biceps tendon ruptures and ruptures at the myotendinous junction are treated in a similar manner. The patient should proceed to strengthening when full painless range of motion is obtained.
Operative intervention is considered when nonoperative management fails for partial ruptures. Usually a minimum 3 to 4 months of observation is appropriate. Patients should be counseled that pain is more of a predominant complaint with these partial injuries.
SURGICAL MANAGEMENT
Complete and Partial Ruptures
The EndoButton (Smith & Nephew, Andover, MA) method of fixation has been shown to have the highest ultimate tensile load.10,16 Clinical studies with the EndoButton have also demonstrated good results with few complications.1,4
Other methods are suture anchor and interference screw fixation.
Chronic Disruptions
The definition of “chronic” is vague. Some authors have stated that greater than 8 weeks is chronic and that a graft is needed in these situations. However, we have been able to primarily repair distal biceps tendon ruptures out to 3 months. In these situations the elbow might not extend beyond 60 degrees on the table, but within 3 months after the repair the patient’s range of motion is full. The biceps brachii, like the pectoralis major, has a significant ability to stretch back out over time.
The surgeon should discuss with the patient that a more chronic rupture might require graft and should discuss the type of graft to be used. Semitendinosus (either autograft or allograft),16 Achilles tendon allograft13 (with the bone plug inserted into the radial tuberosity or just soft tissue repair), flexor carpi radialis autograft,9 and fascia lata6 have been described.
Any of the techniques of radial tuberosity fixation described in the acute section can be used. We use the EndoButton for the chronic reconstructions.
Positioning
The patient is placed in the supine position on an armboard with a sterile tourniquet on the upper arm.
Approach
The approach depends on the surgeon’s preferred method of fixation.
Classic two-incision techniques had complications such as heterotopic ossification and posterior interosseous nerve palsy. Therefore, single-incision anterior approaches were developed with various methods of fixation, including suture anchors, interference screws, and the EndoButton.
TECHNIQUES
ENDOBUTTON
A longitudinal 4 to 5-cm anterior incision starting at the antecubital fossa and extending distally along the ulnar border of the brachioradialis is used. The lateral antebrachial cutaneous nerve and superficial radial nerve are identified and protected.
The distal biceps tendon is retrieved into the wound. This can be accomplished by flexing the elbow and using a retractor to lift the skin of the distal arm for exposure.
The tendon can be adherent to the adjacent tissues or the lacertus fibrosus. This may require a limited tenolysis to mobilize the tendon stump. Protect and isolate the lateral antebrachial cutaneous nerve and the brachial artery.
On occasion, the biceps tendon cannot be retrieved through the anterior incision. In that case, an incision can be made medially along the distal aspect of the arm. The tendon is isolated and prepared and then passed into the distal wound.
Once the tendon is isolated, a no. 2 nonabsorbable suture is woven into the distal biceps tendon using a locking Krackow technique or other locking suture technique. The locking sutures should extend 4 to 5 cm above the stump. The goal is to create a locking stitch proximally and allow about 1 cm of the distal biceps tendon to be unlocked.
The two sutures extending from the tendon stump are then passed through the two central holes of the EndoButton.
The sutures are tied, leaving no space between the end of the tendon and the EndoButton (TECH FIG 1A).
Alternatively, one suture from the tendon can be passed through one of the central holes of the EndoButton and then back through the other central hole and the knot is then tied, thus placing the knot between the EndoButton and the tendon stump.
Passing sutures (kite strings) are placed in the other two holes of the EndoButton.
The radial tuberosity is exposed, and a burr is used to create an oval cortical window roughly the same dimension as the distal tendon stump. This is performed while an assistant holds the forearm in full supination. Two small Bennett retractors can be placed on either side of the radial tuberosity. Then, the EndoButton drill is used to create a hole in the far cortex to pass the button.
TECH FIG 1 • A. EndoButton attached to the distal end of the biceps tendon. B. A Keith needle is placed to pass the suture. C. The tendon is pulled into the proximal radial hole as the EndoButton is advanced through the distal hole. D. The EndoButton is flipped to secure it on the other side of the radial cortex.
Keith needles or a Beath needle are used to pass the passing sutures (kite strings) through the bicortical hole and are retrieved as they pass through the skin on the dorsal side of the forearm (TECH FIG 1B).
One of the passing sutures is independently pulled, drawing the tendon into the radial tuberosity. Continued tension on this kite string draws the EndoButton in its vertical orientation through the hole in the far cortex of the radius (TECH FIG 1C).
Once the EndoButton is on the far side of the radius, the other suture is pulled to flip it and lock it in its horizontal orientation on the far side of the radius (TECH FIG 1D).
We use fluoroscopy to confirm placement of the button.
The passing sutures are then pulled completely out after anatomic tendon placement is visually confirmed.
SUTURE ANCHOR OR INTERFERENCE SCREW FIXATION
The same anterior approach is used, and the tendon is retrieved in a similar manner with both suture anchor and interference screw fixation. However, the radial tuberosity is prepared differently.
In the case of interference screw fixation, a hole is drilled in the radial tuberosity. The diameter of the hole depends on the system (and the size of the screw) being used.
In the case of suture anchor fixation, the radial tuberosity is lightly decorticated and suture anchors of choice are placed. Some authors use two suture anchors, and most use some kind of a sliding knot to advance the tendon onto the bone.
TWO-INCISION TECHNIQUE
The anterior incision is made transverse in the antecubital flexion crease and used to locate the distal tendon stump. A second longitudinal incision is made 1 cm radial to the subcutaneous border of the radius in the proximal forearm at the level of the biceps tuberosity.
Dissection is initially made in the extensor carpi ulnaris muscle and then through the supinator muscle. Take great care to avoid subperiosteal dissection on the ulna to decrease the risk of synostosis.
The forearm is placed in maximal pronation and an oval cavity is created in the biceps tuberosity with a burr. Drill holes are then placed into this cavity with the forearm in supination.
A no. 2 Fiberwire suture is then placed in the distal tendon in a Krackow technique.
The sutures are then passed from anterior to the posterior incision with a long hemostat and retrieved. It is critical to pass the sutures in the interosseous space.
The sutures are then passed through the drill holes and tied over bone with the forearm in supination.
CHRONIC DISTAL BICEPS TENDON RECONSTRUCTIONS
More exposure of the biceps tendon and the myotendinous junction is required for the chronic reconstructions. This can be accomplished by creating a second incision at the medial aspect of the distal arm.
One could connect the two anterior incisions, but this risks creating additional scarring.
A more meticulous dissection is required to protect the lateral antebrachial cutaneous and musculocutaneous nerves. Invariably there will be considerable scarring and adhesions, especially between the biceps tendon and lacertus fibrosus. Some of the lacertus can be used in the reconstruction.
We have used semitendinosus autograft, which is harvested in a fashion similar to that used with anterior cruciate ligament reconstructions.
The tendon is doubled up and the two free ends are woven into the remaining distal biceps tendon and the myotendinous junction (TECH FIG 2A).
A Bunnell tendon passer is very effective at passing the tendon ends.
The length of the graft is chosen so that the reconstruction is tight at 60 degrees of elbow flexion. This can be accomplished by fixing it distally first and then performing the weave, or vice versa.
A nonabsorbable suture is passed through the graft–tendon construct, and this is secured to the radial tuberosity (TECH FIG 2B).
TECH FIG 2 • A. Hamstring tendon is doubled up and folded on itself and the free ends are passed into the distal end of the biceps tendon stump to add length. The free ends of the tendon graft exit laterally. B. The free ends of the hamstrings tendon graft are woven into the biceps tendon stump.
POSTOPERATIVE CARE
Radiographs are obtained at the time of surgery and at the first postoperative visit to ensure that the fixation (EndoButton or anchors) is in good position.
For the EndoButton repair we remove the splint at 2 weeks and allow active and passive range of motion but no lifting greater than a cup of coffee for 6 weeks. Strengthening is then started, but rarely is formal physical therapy necessary.
Other authors have reported good results with early rangeof-motion therapy.1
Others use a more conservative approach and limit full extension until 6 to 8 weeks after surgery.
OUTCOMES
Patient-weighted outcome measures such as the DASH and the MEPS have been used in many studies and have demonstrated excellent results with primary repair.1,5
Objective data including strength testing have also demonstrated good results with anatomic repair, especially with regard to restoring supination strength.8
Chronic repairs or reconstructions have also performed well.17
COMPLICATIONS
Reruptures are rare in most series irrespective of the method of fixation.
Certain fixation methods have been associated with a higher occurrence of certain complications.
Classic two-incision technique: Heterotopic ossification, radioulnar synostosis, and posterior interosseous nerve palsies. Heterotopic ossification and radioulnar synostosis rates have been decreased by avoiding the ulnar periosteum.3,7
Single-incision technique: Lateral antebrachial cutaneous and superficial radial nerve palsies
Loss of motion
REFERENCES
1. Bain GI, Prem H, Heptinstall RJ, et al. Repair of distal biceps tendon rupture: a new technique using the EndoButton. J Shoulder Elbow Surg 2000;9:120–126.
2. Baker BE, Bierwagen D. Rupture of the distal tendon of the biceps brachii: operative versus non-operative treatment. J Bone Joint Surg Am 1985;67A:414–417.
3. Failla JM, Amadio PC, Morrey BF, et al. Proximal radioulnar synostosis after repair of distal biceps brachii rupture by the two-incision technique: report of four cases. Clin Orthop Relat Res 1990;253:133–136.
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5. John CK, Field LD, Weiss KS, et al. Single-incision repair of acute distal biceps ruptures by use of suture anchors. J Shoulder Elbow Surg 2007;16:78–83.
6. Kaplan FT, Rokito AS, Birdzell MG, et al. Reconstruction of chronic distal biceps tendon rupture with use of fascia lata combined with a ligament augmentation device: a report of 3 cases. J Shoulder Elbow Surg 2002;11:633–636.
7. Kelly EW, Morrey BF, O’Driscoll SW. Complications of repair of the distal biceps tendon with the modified two-incision technique. J Bone Joint Surg Am 2000;82A:1575–1581.
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13. Sanchez-Sotelo J, Morrey BF, Adams RA, et al. Reconstruction of chronic ruptures of the distal biceps tendon with use of an Achilles tendon allograft. J Bone Joint Surg Am 2002;84A:999–1005.
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17. Wiley WB, Noble JS, Dulaney TD, et al. Late reconstruction of chronic distal biceps tendon ruptures with a semitendinosus autograft technique. J Shoulder Elbow Surg 2006;15:440–444.