Fresh Osteochondral Allograft to the Humeral Head for Treatment of an Engaging Reverse Hill-Sachs Lesion

摘要

Posterior dislocation of the shoulder is rare, occurring in approximately 2% to 4% of all shoulder dislocations.~( 18 , 32 )Through a mechanism similar to that first characterized by Hill and Sachs,~( 17 )these dislocations have the potential to result in impaction fractures of the anterior aspect of the humeral head.~( 32 , 33 )These so-called reverse Hill-Sachs or McLaughlin~( 26 )lesions are estimated to occur in 86% of acute traumatic posterior shoulder dislocations~( 35 )and are often clinically significant, giving rise to persistent shoulder instability in approximately 35% of cases.~( 32 )An array of treatment options are described in the literature, dependent on factors including but not limited to the location, size, and scale of the defect; mechanism of recurrence; chronicity of the dislocation; and, importantly, the patient’s age, prior activity, and postoperative goals. Osteochondral autograft has been reported rarely, save for a few patients with bilateral fracture-dislocations of the humeral head wherein the contralateral shoulder provides the graft source during treatment with concurrent hemiarthroplasty.~( 8 , 19 )Discussion of osteochondral allograft has focused largely on the treatment of chronic, locked posterior fracture-dislocations.~( 12 , 16 )These authors express concern regarding the potential for degenerative changes associated with chronic instability, suggesting a biomechanical environment distinctly different from lesions treated in the period shortly after initial presentation. In a systematic review of osteochondral allograft for humeral head reconstruction, Saltzman et al~( 34 )identified 2 instances of fresh humeral head osteochondral allograft in humeral head reconstruction. In both instances, the allograft was fixed to adjacent tissue using nonabsorbable compression screws. Several case series involving osteochondral allograft for the treatment of similar Hill-Sachs lesions have been reported using a variety of fixation methods.~( 24 , 25 , 28 )We report the use of fresh osteochondral allograft to the humeral head using a press-fit dowel technique in the context of the spectrum of historical options. Methods A 24-year-old, right hand–dominant male laborer presented to our level 1 trauma center after being struck by a car while riding his bicycle. His injuries were limited to the musculoskeletal system. Physical examination of the left upper extremity elicited shoulder pain with limited passive range of motion. Neurovascular examination of the left upper extremity was otherwise normal. Radiographs indicated a reverse Hill-Sachs lesion and a small cortical irregularity of the posterior glenoid ( Figure 1 ). Figure 1. Preoperative radiograph of the left shoulder illustrating a reverse Hill-Sachs lesion (arrow) and a small, minimally displaced fragment associated with a Bankart lesion of the posterior cortical glenoid. A fracture of the ipsilateral tibial plateau was remarkable, as it required open reduction and internal fixation. This delayed treatment of the symptomatic and unstable index shoulder injury. Magnetic resonance imaging (MRI) ( Figure 2 ) further characterized the shoulder injury. The humeral impaction was estimated to measure approximately 2 cm in width with a depth of approximately 5 mm. Using the methodology described by Nathan and Parikh,~( 27 )the lesion was estimated to involve approximately 33% of the articular surface of the humeral head. A small soft tissue Bankart lesion was minimally displaced adjacent to a posterior cortical glenoid subchondral edema. Shoulder function was both subjectively painful and limiting. This was further assessed via standard outcomes measures. This included a total score of 73 on the American Shoulder and Elbow Surgeons (ASES) scoring system,~( 22 , 31 )an Oxford Shoulder Score~( 10 )of 28, and concomitant health-related quality of life deficits as reflected by Veterans RAND 12-Item Health Survey (VR-12) physical and mental component scores~( 20 )of 37.2 and 48.4, respectively. Figure 2. Preoperative magnetic resonance image of the left shoulder illustrating a reverse Hill-Sachs lesion (arrow) 2 cm in width and 5 mm in depth involving 33% of humeral articular surface. Operative treatment using fresh osteochondral allograft was recommended to address persistent shoulder instability and the limitations reflected by the patient-reported outcome (PRO) scores. Treatment was deferred until the lower extremity fracture was healed and crutch-assisted limited weightbearing was no longer required. Ultimately, this required a delay of 18 weeks from the index shoulder injury to the repair described herein. General anesthesia and a single injection of 20 mL of ropivacaine 0.5% to the interscalene region of the ipsilateral neck provided adequate sedation and pain control for examination and surgery. The patient was positioned in the beach-chair position to obviate the need for traction and provide for an open anterior approach after arthr