Review Question - QID 216809

Transient ulnar nerve neuropraxia remains the most common complication following medial ulnar collateral ligament (MUCL) reconstruction. The ulnar nerve is found between the FCU and FDP muscles in the forearm.

MUCL injuries are characterized by attenuation or rupture of the ulnar collateral ligament of the elbow leading to valgus instability in overhead throwing athletes. Diagnosis is usually made by a combination of physical exam and MRI studies. Initial treatment for most individuals is rest and physical therapy. Surgery is reserved for high-level overhead athletes such as pitchers and those who have failed conservative management. The most common complication following MUCL reconstruction is ulnar neurapraxia, which has a 3-26% incidence. Treatment is often observation as the majority resolve within a few months.

Bruce et al. review the effects of repetitive valgus forces on the throwing elbow. They report that many acute injuries of the throwing elbow are caused by repetitive, chronic wear. They conclude that after failing nonsurgical management, ulnar collateral ligament reconstruction is a viable option to return the throwing athlete to competition.

Cain et al. reviewed injury to the MUCL in overhead athletes leading to symptomatic valgus instability that required surgical treatment. They report that complications occurred in 148 patients (20%). They concluded that MUCL reconstruction with subcutaneous ulnar nerve transposition was found to be effective in correcting valgus elbow instability in the overhead athlete and allowed most athletes (83%) to return to a previous or higher level of competition in less than 1 year.

Incorrect Answers:
Answer 1: Posterolateral rotatory instability (PLRI) is a complication of lateral collateral ligament repair or reconstruction, not medial collateral ligament reconstruction. PLRI is often associated with fractures of the radial head and coronoid tip and is commonly referred to as the terrible triad.
Answer 2: Flexor pronator mass avulsion is more likely with a muscle-detaching approach but is not more common than ulnar nerve neuropraxia.
Answers 4 and 5: The median nerve is found just medial to the brachial artery in the antecubital fossa and is the most volar structure in the carpal tunnel.