Review Question - QID 218954

Injury to the lateral antebrachial cutaneous nerve (LABCN), which originates from the lateral cord of the brachial plexus, is more common with single-incision distal biceps repairs.

Distal biceps ruptures are most common in middle-aged men performing aggressive eccentric activities. This causes the biceps insertion to tear from the radial tuberosity and can lead to deficits in strength, particularly in supination. There are many variations in fixation methods, including single-incision versus double-incision techniques. The single-incision technique is thought to cause a higher rate of injury to the LABCN because of more aggressive, prolonged retraction. The double-incision technique, however, has been described as having a higher rate of heterotopic ossification. This being said, injury to the LABCN is still the most common nerve injury during any distal biceps repair and is typically a neuropraxia that recovers within 3 months.

Castioni et al. performed a meta-analysis looking at single- vs. double-incision techniques for the treatment of distal biceps ruptures. In 2,622 patients, no differences were noted in DASH scores, while the double-incision technique did have a significantly lower risk of LABCN injury (4.2x). The single-incision technique had higher degrees of flexion and pronation motion and a lower rate of heterotopic ossification after surgery.

Grewal et al. also performed an RCT evaluating single- vs. double-incision techniques for the repair of distal biceps ruptures. They found no differences in functional outcomes at follow-up and a slight improvement in flexion strength with the double-incision technique. The single-incision technique was associated with a greater number of LABCN neuropraxias (19) compared to the double-incision group (3)

Amarasooriya et al. reviewed complications after distal biceps repairs, noting general functional outcomes are usually quite good in this population overall. They evaluated 3,091 distal biceps repairs and noted an overall complication rate of 25%, with a major complication rate of 4.6%. They noted the most common injury was LABCN neuropraxia, which occurred in 9.2% of cases and was more common in single-incision techniques.

Incorrect Answers:
Answer 1: The LABCN is the most nerve nerve injury during distal biceps repair, regardless of approach. The PIN is the second most common nerve injured.
Answer 2: Sensation to the volar/radial hand is provided by the median nerve, which is formed by the medial and lateral cords of the brachial plexus.
Answer 3: Injury to the LABCN usually resolves by 3 months postoperatively.
Answer 5: Injury to the LABCN occurs most commonly due to aggressive retraction, not direct laceration.