Shoulder and Elbow cases distal biceps tendon injuries

A 45-year-old, male laborer presents with elbow pain after an injury at work. He was carrying a heavy object, felt it slip, and hyperextended his elbow. He felt a pop and immediate pain in his antecubital fossa. He is neurovascularly intact distally with weakness at the elbow. He has ecchymosis and swelling at the elbow. Hook test is inconclusive.

What is the next most appropriate step in treatment?

1. Sling immobilization until asymptomatic with follow-up examination

2. Physical therapy to focus on elbow range of motion and strengthening

3. Elbow arthroscopy

4. Open exploration of the antecubital fossa

5. Elbow MRI

 

Discussion

The correct answer is (E). This patient has a suspected distal biceps tendon rupture. He has the classic presentation of an eccentric overload injury along with a pop and pain in the antecubital fossa. However, his examination is inconclusive for complete versus partial tendon tear. The hook test is performed by asking the patient to actively flex the elbow to 90 degrees and fully supinating the forearm (see Fig. 2–119). The examiner then attempts to hook their index finger under the lateral edge of the tendon and palpate a cordlike structure representing the biceps tendon. This test has been shown to be both highly sensitive and specific (up to 100%), but it is inconclusive in this case. An MRI is warranted to assess the integrity of the distal biceps tendon, to distinguish between complete versus partial rupture (Fig. 2–120). This could alter management as the optimal treatment of partial tendon ruptures is not entirely clear. There is relative urgency to doing this, as early surgical intervention after injury is preferred to facilitate primary repair.

 

 

 

Figure 2–119 Figures demonstrating the hook test. (A–C) The patient actively supinates with the elbow flexed 90 degrees. An intact hook test allows the examiner to hook their index finger under the intact biceps tendon from the lateral side. (D–E) With an abnormal hook test, there is no cord-like structure under which to hook a finger. (Reproduced with permission from Sutton KM, Dodds SD, Ahmad CS, Sethi PM. Surgical treatment of distal biceps rupture. J Am Acad Orthop Surg. 2010 Mar;18(3):139–48.)

 

 

 

Figure 2–120 MRI depicting distal biceps tendon rupture.

 

What is the most significant strength deficit resulting from nonoperative treatment of a distal biceps tendon injury?

1. Elbow flexion

2. Elbow extension

3. Forearm pronation

4. Forearm supination

5. Shoulder forward flexion

 

Discussion

The correct answer is (D). By its anatomic insertion on the radial tuberosity, the biceps brachii serves as both an elbow flexor and supinator of the forearm. There is a greater percentage loss of supination strength as the brachialis serves as the primary elbow flexor. Nesterenko et al. showed that patients with a unilateral biceps rupture lost 37% flexion strength and 46% supination strength. Different reports exist regarding the effect of biceps injury on elbow endurance. Given the functional deficits associated with nonoperative treatment of complete ruptures, conservative treatment is reserved for only low demand or medically infirm patients in these cases.

What is the most common nerve injury encountered after operative treatment of distal biceps tendon ruptures?

1. Median

2. Radial

3. Musculocutaneous

4. Lateral antebrachial cutaneous

5. Posterior interosseous

 

Discussion

The correct answer is (D). Lateral antebrachial cutaneous neuropraxia is the most common complication of distal biceps tendon repair. It is reported in up to 26% of cases. This is usually the result of excessive retraction and can be avoided with adequate exposure and toe-ing in of the retractors. The nerve pierces the fascia between the biceps and brachialis at the antecubital fossa and runs in the subcutaneous tissues parallel to the cephalic vein. Injury to the radial sensory (6%) and posterior interosseous (4%) nerves has also been reported, although more rare. Pronation of the forearm protects the posterior interosseous nerve. These nerve injuries after distal biceps tendon repair are usually self-limited complications. Other general complications include superficial infection, symptomatic heterotopic ossification, and re-rupture.

Which of the following statements is true regarding one versus two-incision technique for repair of acute distal biceps tendon ruptures?

1. The single incision approach affords a significantly faster recovery time

2. The single incision approach is associated with lower biomechanical strength and higher fixation failure rates

3. The two incision approach is shown to have lower rates of heterotopic ossification

4. The single incision approach is associated with higher rates of neurologic complications, whereas the two incision approach is associated with increased rates of proximal radioulnar joint synostosis

Discussion

The correct answer is (D). This question highlights some controversies surrounding the optimal approach for treatment of distal biceps tendon ruptures. Historically, distal biceps tendon injuries were repaired through a single anterior extensile approach. Due to a high rate of neurologic complications, the Boyd Anderson dual incision technique was developed, and this was further modified to address the complication of radioulnar synostosis (Fig. 2–121). Given that distal bicep tendon

injuries are relatively rare, the literature on this topic comprises mainly small case series. Most contemporary literature suggests that satisfactory outcomes can be obtained with either approach, and that surgeon comfort level should dictate the approach used. No significant differences have been described in regards to recovery time. The biomechanical strength of the construct varies with the type of fixation used and not necessarily the approach. The two-incision approach has been shown in some studies to lead to greater loss of forearm rotation and higher rates of synostosis.

 

 

 

Figure 2–121 CT shows one complication of distal biceps repair: proximal radioulnar joint synostosis.

 

Objectives: Did you learn...?

 

Recognize and diagnose a distal biceps tendon injury?

 

Understand the complications associated with nonoperative and operative management of distal biceps tendon injuries?

 

Appreciate the different approaches available for distal biceps tendon repair?