Increasing innovation in rapid prototyping (RP)
and additive manufacturing (AM), also known as 3D printing, is bringing
about major changes in translational surgical research. This review describes the current position in the use of additive
manufacturing in orthopaedic surgery. Cite this article:
Massive endoprostheses rely on extra-cortical bone bridging (ECBB)
to enhance fixation. The aim of this study was to investigate the
role of selective laser sintered (SLS) porous collars in augmenting
the osseointegration of these prostheses. The two novel designs of porous SLS collars, one with small pores
(Ø700 μm, SP) and one with large pores (Ø1500 μm, LP), were compared
in an ovine tibial diaphyseal model. Osseointegration of these collars
was compared with that of a clinically used solid, grooved design
(G). At six months post-operatively, the ovine tibias were retrieved and
underwent radiological and histological analysis.Aims
Materials and Methods
An experimental sheep model was used for impaction allografting of 12 hemiarthroplasty femoral components placed into two equal-sized groups. In group 1, a 50:50 mixture of ApaPore hydroxyapatite bone-graft substitute and allograft was used. In group 2, ApaPore and allograft were mixed in a 90:10 ratio. Both groups were killed at six months. Ground reaction force results demonstrated no significant differences (p >
0.05) between the two groups at 8, 16 and 24 weeks post-operatively, and all animals remained active. The mean bone turnover rates were significantly greater in group 1, at 0.00206 mm/day, compared to group 2 at 0.0013 mm/day (p <
0.05). The results for the area of new bone formation demonstrated no significant differences (p >
0.05) between the two groups. No significant differences were found between the two groups in thickness of the cement mantle (p >
0.05) and percentage ApaPore-bone contact (p >
0.05). The results of this animal study demonstrated that a mixture of ApaPore allograft in a 90:10 ratio was comparable to using a 50:50 mixture.
