Adverse reactions of artificial bone graft substitutes: lessons learned from using tricalcium phosphate geneX®.
BACKGROUND
Artificial bone graft substitutes are widely used to fill bony defects after curettage of benign tumors. We sought to evaluate the efficacy of one such bone graft substitute, geneX®, which contains tricalcium phosphate and calcium sulphate; however, during the course of this study we observed a high number of complications.


OBJECTIVE
The primary aim of this prospective series was assessment of the effectiveness of geneX® concerning resorption profile and bone healing and remodeling after surgery. We present the types and frequencies of complications observed in patients treated for bone tumors by curettage and filling the defect using geneX®.


METHODS
We planned to study 40 patients; however, after enrollment of the first 31 patients, the study was stopped as a result of serious complications. There were 20 female and 11 male patients with a mean age at surgery of 40 years (range, 6–71 years). Plain radiographs were obtained at different intervals during followup and CT scans were obtained 6 and 12 months postoperatively. Complications were assessed using a 5-point scale according to Goslings and Gouma.


RESULTS
Five of the 31 patients (16%) had complications develop after surgery. In three cases, a sterile inflammation adjacent to the geneX® occurred, with delayed wound healing in two patients and local pain. In the third patient, geneX® produced moderate to severe skin damage in the area of the scar, needing revision surgery. In two other patients, inflammatory cystic formations developed in the soft tissues with sizes up to 15 cm, which gradually reduced in size with time. Overall, there were four Grade 1 complications and one Grade 2 according to Goslings and Gouma.


CONCLUSIONS
We concluded from this series of patients that geneX® causes soft tissue inflammation and pain with its use. Based on this experience we believe that this type of bone substitute should not be used in the treatment of bony defects.


METHODS
Level IV, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.
Joerg
J
Friesenbichler
Werner
W
Maurer-Ertl
Patrick
P
Sadoghi
Ulrike
U
Pirker-Fruehauf
Koppany
K
Bodo
Andreas
A
Leithner
D000293:Adolescent; D000328:Adult; D000368:Aged; D001845:Bone Cysts / Q000209:etiology; D001859:Bone Neoplasms / Q000473:pathology / Q000601:surgery*; D018786:Bone Substitutes / Q000009:adverse effects*; D002130:Calcium Phosphates / Q000009:adverse effects*; D002133:Calcium Sulfate / Q000009:adverse effects*; D002648:Child; D003475:Curettage; D005260:Female; D006801:Humans; D007249:Inflammation / Q000209:etiology; D008297:Male; D008875:Middle Aged; D019637:Orthopedic Procedures / Q000009:adverse effects* / Q000379:methods; D010149:Postoperative Pain / Q000209:etiology; D011183:Postoperative Complications / Q000175:diagnosis / Q000209:etiology* / Q000628:therapy; D011446:Prospective Studies; D012086:Reoperation; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D014945:Wound Healing; D055815:Young Adult
D018786:Bone Substitutes; D002130:Calcium Phosphates; C018392:tricalcium phosphate; D002133:Calcium Sulfate