Direct Anterior Bone Block Grafting for Coronoid Bone Loss and Dysplasia

Abstract

Background: Critical coronoid bone loss (CCBL) can be the key factor of elbow instability, making bony reconstruction essential. Coronoid bone grafting (CBG) is challenging, with a paucity of descriptions in the literature. We present direct anterior CBG in a patient with instability, CCBL (>40%), lateral ulnar collateral ligament (LUCL) insufficiency, and ligamentous laxity who underwent LUCL reconstruction in the same setting. Indications: Isolated ligament reconstruction has a high failure rate in cases with CCBL and therefore requires additional bone grafting. The diagnosis of CCBL is made with lateral radiographs and further quantified by computed tomography imaging. Instability can be best assessed objectively during arthroscopy with a switching stick. CBG performed with an anterior approach facilitates direct access with advantages for plate and screw positioning and access to the proximal radio-ulnar joint. Technique Description: First, LUCL reconstruction was performed. After harvesting of the graft from the iliac crest, the coronoid was exposed with a direct anterior approach. The incision starts centrally medial to the biceps tendon (BT) in the flexion crease extending distally (9 cm). Ligation of multiple vessels (leash of Henry) is required. The deep dissection is continued between the bicipital aponeurosis and BT. Blunt and flat Langenbeck-type retractors are used with care, laterally (BT/radial nerve) and medially (aponeurosis/median nerve). The brachialis muscle is exposed and longitudinally split in line with its fibers, gaining access to the capsule. Harmful retraction on either side of the split has to be avoided. The capsule is incised as a Z-plasty, the coronoid exposed from the joint in the distal direction prior to freshening up the graft bed. The graft is held in place with a wire joystick, sculpted, and temporarily fixed. Joint congruency, stability, and a range of motion (ROM) are checked prior to definitive fixation with a 2.4-mm buttress plate and screws. Results: The coronoid process height was successfully reconstructed from <60% to 100% with durable elbow stability (>1 year), free ROM, and high patient satisfaction. Conclusion: CBG can be standardized and facilitated with a direct anterior approach as a key element for successful elbow stabilization in the setting of CCBL. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.