Cervical Spine Reconstruction in Cases of Compromised Bone Quality

Abstract

( b r a s s m m a p b p t D d r C i B d T he prevalence of patients suffering from end-stage renal disease has increased in the United States (3). With the increasing availability of hemodialysis treatment, these atients are living longer but continue to suffer from the econdary complications of the illness. Renal osteodystrophy ROD) and hemodialysis-associated destructive spondyloarhropathy (DSA) are two related but distinct syndromes. ROD s a direct result of secondary (and rarely primary) hyperparahyroidism and is characterized by alternating areas of subhondral bone resorption, osteomalacia, and osteosclerosis 5). When these bony changes occur in the spine, they do so arallel to the vertebral end plates, creating alternating bands f lucency and sclerosis. The classic radiographic finding of rugger jersey spine” is a reflection of this pattern on lateral pine radiographs, as the alternating bands mimic the design f English rugby jerseys (4, 9, 17). The related phenomenon of emodialysis-associated destructive spondyloarthropathy DSA) was first described by Kuntz (7) in 1984. Kuntz’s group iscovered crystal deposition in the discs and vertebral bodies f patients undergoing long-term hemodialysis for chronic enal failure. This crystal was classified as beta-2-microglobuin ( 2M), a protein that is filtered by the healthy glomerulus, but cannot be filtered by dialysis filters due to its large size. Therefore, dialysis patients may have serum levels of 2M 50 to 60 times normal, resulting in deposition in not only the spine, but also the tendons leading to carpal tunnel syndrome and in the heart causing cardiomyopathy (5). DSA has a similar radiographic appearance to ROD in the spine, with the typical lack of osteophytic change (4). In addition to the compressive and destabilizing lesions that may result from ROD and DSA, surgeons must be aware of the high incidence of comorbidities (6), such as hypertension, diabetes, and coronary artery disease, when caring for patients with end-stage renal dis-