Distal biceps Avulsion discussion 2024

Dr. Smith (Orthopaedic Surgeon)

"Dr. Jones, let's discuss a relatively rare but significant injury—distal biceps avulsions. Can you start by explaining what this injury involves?"

Dr. Jones (Sports Medicine Specialist)

"Absolutely. A distal biceps avulsion occurs when the biceps tendon detaches from its insertion point on the radial tuberosity. This typically happens during a sudden and excessive eccentric contraction of the biceps, such as when someone is lifting a heavy object and the arm is forcefully extended."

Dr. Smith

"Interesting. What’s the typical demographic for this type of injury?"

### **Dr. Jones**:  

"Men in their 40s are the most affected, especially in their dominant arm, and the injury is relatively rare—distal biceps ruptures only make up about 10% of all biceps tendon ruptures. There are some key risk factors too, like anabolic steroid use, smoking, and age-related degeneration of the tendon."

### **Dr. Smith**:  

"So, if a patient comes in with this injury, how would we diagnose it?"

### **Dr. Jones**:  

"Clinically, a full tear can often be identified using the **hook test**, where the examiner tries to hook their finger under the biceps tendon. If the tendon is completely ruptured, you won’t be able to 'hook' the tendon. If the results are unclear, an MRI can distinguish between a complete tear and a partial one, and it can show the degree of tendon retraction or any muscle damage."

### **Dr. Smith**:  

"Once you’ve diagnosed the tear, how do you determine whether to go with nonoperative or operative treatment?"

### **Dr. Jones**:  

"That depends on several factors—age, activity level, the chronicity of the injury, and whether it's a partial or complete tear. For older, less active individuals, nonoperative management, such as physical therapy, might suffice. But younger or more active patients often require surgical repair, especially if they want to preserve full function of the arm."

### **Dr. Smith**:  

"Speaking of function, how does this injury affect strength, particularly with movements like supination and flexion?"

### **Dr. Jones**:  

"Patients with an untreated distal biceps avulsion can lose significant strength—around 50% for sustained supination and 30% for flexion. Supination is more impacted than flexion because the distal biceps plays a critical role in rotating the forearm."

### **Dr. Smith**:  

"That's quite a loss of function! What does the surgical repair process typically look like?"

### **Dr. Jones**:  

"Surgical repair involves reattaching the tendon to the radial tuberosity, and there are several techniques. One common method is the **single-incision approach**, where the tendon is anchored back to the bone, while carefully avoiding injury to the nearby nerves. The two-incision technique is another option, which is designed to reduce the risk of nerve injury but carries a higher risk of complications like heterotopic ossification, or abnormal bone growth."

### **Dr. Smith**:  

"Are there any complications surgeons should watch out for with these procedures?"

### **Dr. Jones**:  

"Yes, the most common complications are nerve injuries, particularly to the **lateral antebrachial cutaneous nerve (LABCN)**, which can cause temporary numbness. Injuries to the **posterior interosseous nerve (PIN)**, though rarer, can be more severe. There’s also the risk of heterotopic ossification, which is more likely with the two-incision approach, and synostosis, where abnormal bone forms between the radius and ulna."

### **Dr. Smith**:  

"And post-surgery, what's the usual rehabilitation process?"

### **Dr. Jones**:  

"Postoperatively, the elbow is usually immobilized in flexion and slight supination to allow for healing. Gradual mobilization follows after a few weeks, but full recovery can take several months, with physical therapy focusing on restoring strength and range of motion."

### **Dr. Smith**:  

"Thanks, Dr. Jones, this was an insightful discussion. Distal biceps avulsions may be rare, but it’s crucial to diagnose and manage them properly to avoid long-term disability, especially in younger, active patients."

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