Technique Spotlight: Ulnar Collateral Ligament Reconstruction

Introduction

Ulnar collateral ligament (UCL) reconstruction has grown dramatically in popularity and utilization since the time of Frank Jobe and Tommy John. Over this period, UCL reconstruction constructs have evolved significantly from the original Jobe technique. Modifications have included refinements in approach, ulnar nerve (UN) management, tunnel positioning, and graft fixation. Today, “docking” techniques offer the benefit of sparing the common flexor tendon (CFT) origin, standardizing tunnel placement, facilitating graft passage and tensioning, and optimizing biomechanical construct strength. Modern studies consistently demonstrate return to play at the same level or higher in 85%–90% of patients with the use of current docking techniques. Despite these advancements, complications and failures continue to occur. To achieve optimal outcomes while minimizing complications, it is critical to adhere to strict indications, meticulous surgical technique, and structured rehabilitation. This chapter is designed to provide a concise summary and description of a modified docking technique with a focus on key surgical pearls and pitfalls.

Surgically Relevant Anatomy and Biomechanics

As with all surgical reconstructions, successful UCL reconstruction relies on a complete understanding of the anatomy, biomechanics, and material properties of the native ligament. The UCL is composed of three separate bundles: the anterior, posterior, and transverse bundles. The anterior bundle is comprised of two distinct bands: the anterior band and the posterior band. The anterior bundle originates on the humerus from a flat surface, 11.7–13.4 mm anterior (lateral) and inferior (distal) to the medial epicondyle (ME). ^, It traverses the joint and inserts over a broad attachment centered over the sublime tubercle (ST), tapering along the ulnar ridge with a total footprint length of almost 3 cm. ^{, ,} Between footprints it has a total reported length of just over 5 cm. ^,

Biomechanically, the stability of medial elbow can be broadly categorized into dynamic and static stabilizers. Dynamic stability is provided by the flexor-pronator mass (FPM), while static stability is primarily conferred by the UCL and medial joint capsule. Of the dynamic stabilizers, there are significant contributions from the flexor carpi ulnaris (FCU), flexor digitorum superficialis (FDS), and flexor carpi radialis (FCR), with the FCU being the most significant stabilizer of the FPM. ^, Statically, the UCL provides the majority of stability to valgus stress of the elbow. The anterior bundle is the primary restraint to valgus stress, and as a consequence, is the most frequently injured and the focus of surgical reconstruction. The anterior bundle has the highest strength and stiffness of the stabilizers with a mean load to failure of 260.9 N. However, this is regularly exceeded by the valgus torques imposed during overhead throwing leading to repetitive trauma and eventual tearing. ^, The consequences of UCL injury have been quantified in cadaveric models demonstrating increased valgus instability of 3.2–11.8 degrees depending on the degree of elbow flexion. As our understanding of the anatomy and biomechanics have evolved, so too have reconstruction techniques in an effort to more accurately restore the function of the UCL.

Surgical Indications

The primary surgical indication for UCL reconstruction is persistent medial elbow pain and dysfunction despite a trial of nonoperative treatment, or acute full-thickness UCL tear, coupled with the desire to return to competition at the same level or higher. Nonoperative management should include a structured rehabilitation program with at least 3 months of rest and gradual return to throwing. Surgery may be considered earlier in patients with evidence of complete UCL rupture on examination and imaging. Contraindications to surgery include significant concomitant ulnotrochlear or radiocapitellar arthrosis and inability or unwillingness to participate in the rigorous postoperative rehabilitation program. UCL reconstruction should never be offered to improve performance including pitching velocity, accuracy, or stamina.

Technique