Patients with an indication for spondylodesis are included according to the inclusion
criteria and exclusion criteria. Subsequently, randomization into the MySpine and
conventional group is performed. Patients remain blinded to the randomization.
On the basis of a computed tomography, the surgeon plans the entry points, the screw size
and length, as well as the angle of the screws in two planes (sagittal and axial) on the
computer. In the MySpine group, a three-dimensional, digital reconstruction of the spine
is made using Medacta International SA software. On the basis of these planning files,
three-dimensional templates with guide channels (guides) are produced for each individual
vertebra. These guides can be applied dorsally to the bony anatomy and thus specify the
entry points as well as the direction of the screw. Also, replicas of the individual
vertebra are produced in the 3D printer.
The patients are operated in a prone position via a dorsal approach. After preparation of
the dorsal process, vertebral arches and vertebral joints as well as the transverse
process, the screws are implanted with one of the following methods depending on the
randomization:
Freehand (fluoroscopically controlled)
MySpine System
Postoperatively, all patients undergo computed tomography of the operated area. On the
basis of this computed tomography the number of pedicle perforations as well as their
extent should be determined according to the simplified Laine classification. These
results are to be statistically evaluated with the question of whether there are
significant differences between the two techniques with respect to the absolute and
individual number of pedicle perforations, as well as their extent. It is also to be
examined whether these results show a dependence on the level of experience of the
surgeon.
In addition to the individual radiation exposure (cumulative irradiation time in seconds
and irradiation dose in cGy), the time for the dorsal instrumentation for each of the two
systems per surgeon is also to be measured and evaluated.
In the follow-up, the outcome is also recorded by means of pain registration, ODI score
and complication detection (infections, pedicle fractures, implant loosening,
pseudoarthrosis, re-operations).
The follow-up assessments 6 weeks, 6 months, 1 year and 2 years after surgrey are
peformed according to institutional standards.