Use of Hydroxyapatite Blocks in Posterior Interbody Fusion

When a patient is aged and osteoporotic, the collapse of the graft bone used in lumbar interbody fusion is a common problem [1] and occurs even if some type of spinal instrumentation such as a Zielke system or Steffee VSP plate is added. Before 1988, we performed posterior lumbar interbody fusion (PLIF), using only autograft with spinal instrumentation. Among 19 patients whose age was over 60.3 (16%) had graft bone collapse which resulted in pseudoarthrosis. Pain at the donor site is also a common complaint after surgery. To prevent these problems, we have used a hydroxyapatite (HA) block as the interbody spacer, and we will analyze the results here.