The use of beta-tricalcium phosphate and bone marrow aspirate as a bone graft substitute in posterior lumbar interbody fusion.
OBJECTIVE
Due to the disadvantages of iliac crest bone and the poor bone quality of autograft gained from decompression surgery, alternative filling materials for posterior lumbar interbody fusion cages have been developed. β-Tricalcium phosphate is widely used in cages. However, data regarding the fusion rate of β-TCP assessed by computer tomography are currently not available.


METHODS
A prospective clinical trial involving 34 patients (56.7 years) was performed: 26 patients were treated with single-level, five patients double-level and three patients triple-level PLIF filled with β-TCP and bone marrow aspirate perfusion, and additional posterior pedicle screw fixation. Fusion was assessed by CT and X-rays 1 year after surgery using a validated fusion scale published previously. Functional status was evaluated with the visual analogue scale and the Oswestry Disability Index before and 1 year after surgery.


RESULTS
Forty-five levels in 34 patients were evaluated by CT and X-ray with a follow-up period of at least 1 year. Clinically, the average ODI and VAS for leg and back scores improved significantly (P < 0.001). CT assessment revealed solid fusion in 12 levels (26.67%) and indeterminate fusion in 15 levels (34.09%). Inadequate fusion (non-union) was detected in 17 levels (38.63%).


CONCLUSIONS
The technique of PLIF using β-TCP yielded a good clinical outcome 1 year after surgery, however, a high rate of pseudoarthrosis was found in this series therefore, we do not recommend β-TCP as a bone graft substitute using the PLIF technique.
Department of Orthopaedic Surgery, Innsbruck Medical University, Anichstrasse 35, 6020, Innsbruck, Austria. martin.thaler@uki.at
Martin
M
Thaler
Ricarda
R
Lechner
Michaela
M
Gstöttner
Conrad
C
Kobel
Christian
C
Bach
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016026:Bone Marrow Transplantation / Q000379:methods*; D001863:Bone Screws; D018786:Bone Substitutes / Q000627:therapeutic use*; D016025:Bone Transplantation / Q000379:methods*; D002130:Calcium Phosphates / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011859:Radiography; D013123:Spinal Fusion / Q000379:methods*; D016896:Treatment Outcome
D018786:Bone Substitutes; D002130:Calcium Phosphates; C485817:beta-tricalcium phosphate