Management of Distal Biceps Tendon InjuriesBrachii

Abstract

The primary function of the distal biceps tendon is forearm supination. It also acts as a secondary flexor of the elbow.The distal biceps tendon inserts on the far ulnar and posterior aspect of the bicipital tuberosity. The incidence of distal biceps tendon ruptures is estimated to be 1.2 per 100,000 patients with the peak incidence occurring in the fourth and fifth decades. Various theories about predisposing factors have been proposed including tendon avascularrity, mechanical impingement, tendon degeneration and attritional causes of rupture. Prominence of the bicipital tuberosity may erode the tendon during pronation, predisposing it to rupture when subjected to high forces. The diagnosis of a full rupture is a clinical one. Imaging studies are not always necessary but are helpful in excluding other pathologies at the elbow. Irregularities at the radial tuberosity or an avulsion fleck can sometimes be seen on standard radiographs, but a normal image definitely does not exclude a distal biceps rupture. Ultrasound can be used if the diagnosis is not clear. It can confirm the absence of the tendon in its normal location. Magnetic resonance imaging (MRI) has a 92-100% sensitivity and 82.5-85% specificity to detect complete distal biceps ruptures. For partial tears, the sensitivity and specificity are 59% and 100%, respectively. An early anatomical repair is the treatment of choice due to the ease of thetechnique and better outcome. The complication rate increases in delayed Repairs Three different surgical treatments exist: Anatomical repair (mostly in acute cases), reconstruction (mainly in chronic cases) and non-anatomical tenodesis to the brachialis tendon in order to partially restore flexion strength (in chronic cases). Single anterior incision techniques with suture to bone reconstruction have been described, but the increased incidence of radial and posterior interosseous nerve injuries led to introduce a double incision technique. This involved a posterolateral incision in addition to a small anterior approach. The development of radioulnar synostosis with this technique was attributed to subperiosteal exposure of the ulna which may lead to interosseous membrane damage and periosteum stimulation. Thus, a modification of this technique added a muscle splitting approach through the common extensor tendon in order to avoid this complication. Different fixation methods are available. Traditionally transosseous tunnels were used, but newer devices have made the fixation easier. These include suture anchors,EndoButton, interference screws and hybrid technique,In thesecurrently available techniques, fixation with cortical buttons provides the highest load and stiffness. Rehabilitation in the early postoperative phase includes protecting the repaired tendon, preventing elbow joint stiffness, and instruction in one-handed adaptive activities of daily living techniques. Subsequently, in the fibroplasia stage of tendon healing the focus is on regaining muscle tendon unit length through maintained muscle stretch, as active muscle function is frequently easily achieved. The overall complicationsrate following surgical repair is just under 20%. Traditionally radioulnar synostosis has been the commonest and most disablingadverseoutcome following the two-incision technique with arate of 9%. Transient or permanent nerve palsies are the most commoncomplication after single incision techniques (12%), but newer fixationmethods have made the repair easier with less dissection necessaryreducing this risk to 7%. The risk of heterotopic ossification is 3-6%,Infection less than 2% and elbow contracture 1%. Re-rupture rarelyoccurs.