Distal Biceps tendon rupture

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1 Distal Biceps tendon rupture Rupture of the distal biceps tendon is uncommon but seems to be increasing. It occurs in men in their forties to sixties, it is extremely rare in females. It usually affects the dominant arm and follows an injury where a sudden increased load is placed on the tendon while the muscle is actively contracting. Most people think the biceps muscle is the main muscle that flexes your elbow. This is not the case, the main elbow flexor is a deeper muscle (Brachialis). The biceps muscle does provide some flexion strength but its main function is powerful supination. It is important to differentiate a rupture of the DISTAL biceps tendon (at the elbow) as opposed to a rupture of the LONG head of biceps which happens at the shoulder. Anatomy The biceps muscle has two areas of attachment at the elbow: Biceps tendon proper (distal) - This is the principal attachment, the tendon attaches to a bony prominence on the radius called the bicipital tuberosity. The biceps tendon proper may also have two components to it, they both attach to the bicipital tuberosity. Lacertus fibrosis (Bicipital aponeurosis) - The lacertus fibrosis is a condensation of the forearm fascia, is less distinct than the biceps tendon proper. The biceps is a weak flexor of the elbow, but a strong supinator. The nerve supply is via the musculocutaneous nerve, this nerve ends in a branch called the Lateral antebrachial cutaneous nerve (LABCN), this supplies sensation to the lateral side of the forearm. This is important as injury to the tendon and retraction of the muscle may pull on this nerve, leading to pins and needles and pain radiating down the lateral aspect of the forearm. Diagnosis The diagnosis may be missed as the elbow can still flex/ extend and pronation and supination is still possible using other muscles. The history/ story is important, loading the flexed elbow and suddenly feeling something snap in the elbow. Followed by pain and swelling around the front of the elbow. Occasionally pain and tingling/ numbness might radiate down the forearm as one of the nerves in the elbow may be involved. Bruising around the elbow and forearm may develop/ come out over a few days. A distinct tendon is no longer felt in the front of the elbow and the biceps muscle may bunch up. It is possible to only tear part of the tendon and part of the biceps muscle attachment may remain intact (lacertus fibrosis). This may limit the amount the biceps bunches up. Xrays of the elbow are often normal, but required to ensure no fracture and no bony abnormalities of the radius.

2 An Ultrasound or MRI scan may be required if the history and physical examination are not classic. Several variations of injury exist: Complete rupture of biceps tendon and lacertus fibrosis Complete rupture of biceps tendon, leaving lacertus fibrosis intact Partial rupture of the biceps tendon Rupture of musculotendinous junction (here the muscle tears off the tendon as opposed to the tendon pulling off the bone) Treatment There are two treatment options: Non operative Operative As is the case with quite a lot of upper limb trauma there is no universal treatment for everyone. It is a case of deciding on your expectations following the injury and balancing that with the potential risks and complications you are willing to face in order to achieve your goal. Most people think that following a rupture of the biceps tendon they will have a very weak arm that does not bend and will not work well. This is not the case, with non operative treatment and rehabilitation of the other muscles around the elbow it is possible to get a good arm, this is at very little risk. If you want to "go for gold" so to speak and want the strongest/ best arm you can have then an operation should be considered, with the attendant risks and complications. Non operative treatment Non operative treatment involves, relative rest for a few weeks waiting for the bruising and swelling to resolve. Keep the elbow gently moving so it does not stiffen up (see stiff elbow and stretches). As the pain and discomfort resolves begin a gradual increase in activities and strengthening of of the remaining muscles of around the elbow. (see stiff elbow and strengthening). From JSES 2009 This is average muscle strength in arm following rupture of distal biceps, median time from injury 2.9 months, range (2weeks to 3 years). Loss of strength in flexion and extension is better represented below as a % of the uninvolved arm.

3 The information is from three different studies all with different angles on the same theme. (JBJS A 1985, JBJS 2009, JSES 2009) In essence what they and other studies have shown is that acutely flexion and supination strength decreases with rupture of the distal biceps tendon. With time as the injury resolves and the other muscles around the elbow and forearm take up some of the work of the biceps muscle, the deficit in strength reduces. On average with non operative treatment you are likely to regain: 70% flexion strength around 3 months (JSES 2009) 85% flexion strength after 1 year (JBJS 2009) 50% Supination strength around 3 months (JSES 2009) 75% supination strength after 1 year (JBJS 2009) This is maximum strength. Patients often complain of a degree of fatiguability of the muscles. In reality the muscles do not fatigue faster, the symptoms of fatiguability probably relate to the fact that you start off with relatively lower peak strengths. This is most likely to be noticed in actions requiring repeated supination (eg. using a screwdriver). Operative treatment Operative treatment involves re-atachment of the biceps tendon to the bicipital tuberositity. There are several methods of exposing the tendon and several methods of re-ataching the tendon to bone, using transosseous sutures, bone anchors, endobuttons and or inteference screws. I use a single incision endobutton technique for acute repairs. It is much easier to repair the tendon if done acutely (within 3-4 weeks). If delayed longer than this the skin wound needs to be larger and if the muscle and tendon have retracted proximally a long way then on occasion the gap needs to be grafted. I use a hamstring from behind the knee. As with all surgery there are always the potential of risks and complications. The more difficult the surgery the higher the potential for risks and complications. It is important to balance these potential risks and complications with the potential benefits (gain in function) after surgery. In essence an acute repair (ie within 3-4 weeks) is relatively straightforward and can usually be accomplished through a 4 cm cut on the front of the forearm. If surgery is delayed longer than this things become more complicated, rehab time may be

4 longer and I always discuss the potential need for a tendon graft if the muscle has retracted proximally a long way. Complications of operative treatment Complication rates of up to 25% have been reported following surgical repair. Mostly related to injuries of the nerves around the elbow. Other complications include: Nerve injury Heterotopic ossification (the formation of extra bone, this is a bigger problem with the two incision technique) Persistent pain Stiffness (both flexion and extension, more problematic is rotation) Infection Complex regional pain syndrome Re rupture Ultimately no right or wrong Benefits of operative treatment Surgery can restore near full flexion and supination strength (over 90%). Some patients treated non operatively will have persistent pain. It is still possible to operate at a later date but is technically more demanding and a primary repair may not be possible, needing a tendon graft. Cosmetically, with non operative treatment the shape of the biceps muscle will never return to normal. Benefits of Non operative treatment Avoid all the risks of surgery. No restriction on return to activity/ work, as bruising and swelling resolves increase use of arm gradually loading and rehabilitating the tendon. Acute loss of strength will improve with time achieving 85% of flexion strength and 75% supination strength. Ending up with good residual strength and arm function and little overall disability. If you want a good arm with very little risk and are willing to accept the cosmetic appearance and only slightly reduced strength then it is best not to have an operation. Avoiding all the potential risks and complications of an operation If you want to go for Gold and have the strongest arm and more normal appearance AND you are willing to undertake the risks and potential complications of an operation then it is best to have an acute repair. References Proximal radial fracture after revision of distal biceps tendon repair: A case report; Alejandro Badia, S.N. Sambandam, Prakash Khanchandani; Journal of Shoulder and Elbow Surgery; March 2007 (Vol. 16, Issue 2, Pages e4-e6) Elbow strength and endurance in patients with a ruptured distal biceps tendon.; Nesterenko S, Domire ZJ, Morrey BF, Sanchez-Sotelo J.; J Shoulder Elbow Surg Aug 5

5 Nonoperative Treatment of Distal Biceps Tendon Ruptures Compared with a Historical Control Group; Carl R. Freeman, Kelly R. McCormick, Donna Mahoney, Mark Baratz, and John D. Lubahn; J. Bone Joint Surg. Am., Oct 2009; 91: Rupture of the distal tendon of the biceps brachii. A biomechanical study; Morrey BF, Askew LJ, An KN, Dobyns JH.. J Bone Joint Surg Am. 1985;67:418-21