Review Question - QID 219907

The most common nerve injury following a single incision distal biceps repair is transient neuropraxia of the lateral antebrachial cutaneous nerve, which is the sensory continuation of the musculocutaneous nerve (A in Figure A).

Distal biceps tendon ruptures typically occur in the dominant arm, with a greater prevalence in males between the ages of 30 and 50. Nonoperative treatment results in long-term functional deficits, predominantly in loss of supination; therefore, operative repair serves as the mainstay of treatment. Traditionally, the surgery is performed through either a single anterior incision or a double-incision approach. Comparatively, the single-incision approach carries an increased risk of nerve injury. The lateral antebrachial cutaneous nerve (LABCN), the terminal sensory branch of the musculocutaneous nerve (Figure 1, Label A), is most commonly injured with this approach, resulting in lateral-volar forearm numbness. Most cases occur from excessive traction on the nerve during the surgery and resolve spontaneously 3-6 months after surgery. In rare circumstances, the LABCN injury results in a permanent sensory deficit or neuroma formation. The posterior interosseous nerve (PIN), a branch of the radial nerve (Figure 1, Label C), may also be injured, resulting in wrist and finger extension loss. Injury to the PIN is far less common and is avoided with careful dissection around the radial neck where the nerve traverses.

Amin et al. performed a meta-analysis to evaluate outcomes following single or double-incision surgical techniques for distal biceps repair. The authors found that lateral antebrachial cutaneous nerve neurapraxia was the most common complication in the single-incision group (10%), while heterotopic ossification was the most common complication in the double-incision group (7.2%). These findings allow surgeons to make informed surgical decisions and provide patients with accurate information regarding outcomes and potential complications.

Frank et al. review biceps tendon pathology, including proximal and distal pathology. The authors describe distal bicep anatomy and common pathology with its accompanying clinical presentations. They emphasize the lack of consensus on the surgical approach and fixation strategy and ultimately recommend meticulous surgical techniques to optimize outcomes.

Figure A shows the brachial plexus with the following nerves unlabeled:
A: Musculocutaneous; B: Axillary; C: Radial; D: Median; E: Ulnar. Illustration 1 is a labeled version of Figure A.

Incorrect Answers:

Answers 2-5: The lateral antebrachial cutaneous nerve is the most common nerve injury following single-incision distal biceps repair. It is a sensory branch of the musculocutaneous branch, labeled A.