A Radiographic and Patient Based Outcome Analysis of Different Bone Grafting Techniques in the Surgical Treatment of Idiopathic Scoliosis: Allograft vs. Autograft/Allograft Combination

Summary: A retrospective analysis of patients with idiopathic scoliosis treated with posterior instrumentation and arthrodesis using either allograft (46) or autograft and allograft (28) showed no statistically significant difference in early or late pain as determined by SRS-22 pain domain scores. There was no difference in pseudarthrosis rate.

Study Design: This is a retrospective study analyzing the use of crushed corticocancellous allograft or the combination of iliac crest autograft and crushed corticocancellous allograft as the source of graft material in 74 patients treated with posterior spinal instrumentation and arthrodesis for adolescent idiopathic scoliosis. Our hypothesis is that the addition of autogenous bone graft decreases early pain due to earlier arthrodesis healing.

Materials and Methods: From 1997 and 2001, 46 patients were treated with allograft, and between 1997 and 2002, 28 patients received a combination of autograft and allograft. Routine radiographs as well as SRS-22 and SRS-24 were obtained before and after the surgery.

Results: Allograft: The average pre-operative largest curve was 52°, postoperative correction was to 20° and at latest follow-up it was 18°. Complete SRS pain domain scores collected for 33/46 of these patients at pre-op, 1, 6, 12 and 24 month periods were 4.10, 3.35, 3.89, 4.41, and 4.34 respectively. There was 1 pseudoarthrosis in this group, which required re-operation. There were 2 patients with a superficial wound dehiscence, also requiring re-operation. Combination: The average pre-operative largest curve was 62°, postoperative correction was to 21° and at latest follow-up it was 22°. The SRS pain domain scores completed for 23/28 of these patients at pre-op, 1, 6, 12 and 24 month periods was 4.08, 3.74, 4.13, 4.59, and 4.39 respectively. There were no pseudoarthroses in this group and one stitch abscess not requiring re-operation.

Conclusion: At two years follow-up, no statistical difference in pain scores is noted. There was no statistical difference in the occurrence of pseudoarthrosis and no increase in complications related to bone graft in the combination patient population. Our hypothesis that the addition of autogenous bone graft decreased early pain due to rapid bone healing was not supported by the data.