The success of a bone graft depends partly on the surgical technique used, but this is not the only consideration. For onlay grafts, the following points apply:
Preparation of the recipient site
The recipient site is the entry point for healing of the graft and must bleed so that the graft is rapidly saturated with blood. This step can be completed in several ways, notably by:
- Making small holes using a pointer,
- Gently “stroking” the surface of the bone with a spherical disk cutter for mild decortication,
- Scarifying the bone surface with a disk cutter.
Adaptation and preparation of the bone graft
Healing of a bone graft always occurs via establishment of a fibrin network to ensure good graft stability. This is assured via establishment of neovascularisation and integration of the bone block. The three essential steps for satisfactory preparation are as follows:
- Adaptation of the graft to the recipient site using a bone disk cutter. This step may be omitted if a custom graft completed using the patient’s DICOM files is used,
- Preparation of osteosynthesis screw holes,
- Preparation of notches for the screw heads.
Closure of soft tissues without tension
A sufficient volume of residual bone is required at the site for graft fixation. Pay attention to the interradicular spaces for the fixation screws.
Protocol:
- Rehydration of the block for 5 to 10 min (0.9% sodium chloride),
- Opening of site/flap detachment,
- Adaptation of the plate at the recipient site (rapid rotation bone disk cutter with irrigation),
- Objective: closest possible plate/recipient site contact,
- Pay attention to the graft angles,
- Decortication of the recipient site (spherical disk cutter) or cortical perforation (drill): blood clot,
- Positioning of the graft and placement of the osteosynthesis screw,
- Dissection of the periosteum (light scalpel slices inside the flap): elasticity of the soft tissues,
- Suturing of the flap without tension: watch out for perioperative oedema as the soft tissues swell.
