Biomedical Engineering Reference
In-Depth Information
shaped blocks (custom-designed) for spine arthrodesis (cage insert) and wedges
for tibial valgisation osteotomy.
4.5.2.1 Cervical Spine Arthrodesis.
Several studies have been pub-
lished using bioceramic inserts for fi lling cage fusion [121 - 124] . Mousselard [125]
recently reported a clinical study of a prospective, comparative, multicentre and
randomized study comparing iliac grafts and a macroporous BCP.
4.5.2.2 Anterior Cervical Fusion with PEEK Cage.
Peek cervical radiolu-
cent fusion cages provide immediate mechanical support after anterior cervical
discectomy. The aim of this study was to compare the clinical effi ciency and qual-
ity of the fusion after reconstruction with an anatomically-shaped PEEK cage
associated with an iliac crest autograft or with MBCP in the surgery of cervical
disc. The addition of an iliac autograft makes possible an excellent fusion rate,
but is associated with increased morbidity and persistent pain at the donor site.
Clinical reports by Scareo prospectively comparing the two techniques has shown
the clinical advantage of using MBCP and avoiding bone graft harvesting. Fifty-
eight patients were selected in a multicentre, comparative and prospective study
with 24-month follow-up. The patients undergoing anterior cervical decompres-
sion and fusion were randomised for autologous graft or MBCP. After 24 months,
cervical X rays showed 87% complete fusion, 13% uncertain fusion and 0% real
pseudarthrosis in the autograft group versus 86%, 10% and 4%, respectively, in
the MBCP group. No implant failures were recorded. These results suggest that
the use of an insert associated with an anterior cage allows better recovery for
patients while achieving a fusion rate similar to that of ACDF with a tricortical
graft, and does not have the associated complications. Using an MBCP insert is
safe and avoids potential graft site morbidity and pain in comparison with an
autologous graft procedure.
4.5.2.3 High Tibial Valgisation Osteotomy (HTO).
Many surgical pro-
cedures have been described for high tibial valgisation osteotomy (HTO) as a
treatment for medial femorotibial arthritis with genu varum deformity. Filling
the cavity created by the opening has remained a problem, although various
osteosynthetic solutions have been proposed. Bone substitutes have been used in
a number of different cases [126-128].
A single centre prospective study [129] from December 1999 to December
2002 was completed involving 42 patients (13 females and 29 males, average
age 46 years) who underwent HTVO with medial addition for various types of
deformity using custom-designed wedges made of micro-macroporous biphasic
calcium phosphate bioceramic bone substitute and an orientable locking screw
plate (Numelock II®, Stryker). After one year, correction was unchanged in
99.5% of the cases. Histological analysis showed MBCP resorption and bone
ingrowth into the pores and at the expense of the bioceramic. Residual MBCP
fragments showed ingrowth of trabecular and/or dense lamellar bone both on
the surface and in the macropores. X-ray radiography and microCT revealed a
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