The efficacy of porous hydroxyapatite bone chip as an extender of local bone graft in posterior lumbar interbody fusion

Abstract

Objective: To evaluate whether a synthetic bone chip made of porous hydroxyapatite can effectively extend local decompressed bone graft in instrumented posterior lumbar interbody fusion (PLIF).

Methods: 130 patients, 165 segments, who had undergone PLIF with cages and instrumentation for single or double level due to degenerative conditions, were investigated retrospectively by independent blinded observer. According to the material of graft, patients were divided into three groups. HA group (19 patients, 25 segments): with hydroxyapatite bone chip in addition to autologous local decompressed bone, IBG group (25 patients, 28 segments): with autologous iliac crest bone graft in addition to local decompressed bone and LB group (86 patients, 112 segments): with local decompressed bone only. Radiologic and clinical outcome were compared among groups and postoperative complications, transfusion, time and cost of operation and duration of hospitalization were also investigated.

Results: Radiologic fusion rate and clinical outcome were not different. Economic cost, transfusion and hospital stay were also similar. But operation time was significantly longer in IBG group than in other groups. There were no lasting complications associated with HA and LB group with contrast to five cases with persisting donor site pain in IBG group.

Conclusion: Porous hydroxyapatite bone chip is a useful bone graft extender in PLIF when used in conjunction with local decompressed bone.

Fig. 1

Lateral simple radiography of the 57 years of female patient with degenerative spondylolisthesis and spinal stenosis at L3-4-5 level, who undergone double level PLIF with porous hydroxyapatite bone chip in addition to local decompressed bone. a Immediate post-operative image showing clotty radio-opaque shadow of hydroxyapatite bone chips in interbody space. b 3 months after operation, irregular pattern of mixed radio-opaque and -lucent shadow is seen presumably due to uneven resorption of graft materials. c 12 months postoperatively, more organized shadow is observed representing trabecular bridging across interbody space