Pedicle Screw Fixation of Spine
Conditions
Keywords
Robotic assisted, Pedicle screws, Spinal implants, Spinal disorder, Spine, Surgery, Surgical technique
Brief summary
This prospective multicenter observational cohort study evaluates robotic-assisted pedicle screw placement compared with non-robotic-assisted techniques in spinal surgery. Primary objectives include screw placement accuracy, operative learning curve, and reoperation rate within 2 years.
Detailed description
Pedicle screw fixation is widely used in spinal surgery. Screw misplacement may cause complications and reoperations. Robotic-assisted systems aim to improve accuracy and workflow; however, high-quality real-world evidence regarding long-term clinical outcomes and cost-effectiveness remains limited. This nationwide cohort study includes consecutive patients undergoing spinal surgery with pedicle screws. Exposure is robotic-assisted versus non-robotic-assisted (navigation-assisted or freehand) screw placement. Data capture is made from registries, radiographs and hospital data. Follow-up is up to 2 years for the primary outcomes and up to 5 years for the secondary outcomes.
Interventions
DEVICERobotic-assisted pedicle screw placement
Robotic-assisted pedicle screw placement using commercially available robotic systems
Sponsors
Uppsala University
Uppsala University Hospital
Ôrebro University Hospital
Umeå University
Umeå University Hospital
Karolinska Institutet
Karolinska University Hospital
Södersjukhuset (Stockholm South General Hospital)
Sahlgrenska University Hospital
University of Linköping
University Hospital, Linkoeping
Lund University
Skane University Hospital
Länssjukhuset Ryhov
Länssjukhuset Kalmar
Örebro University, Sweden
Göteborg University
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Healthy volunteers
No
Inclusion criteria
* Treatment with pedicle screws in the cervical, thoracic, lumbar spine and/or sacrum. * All ages and spinal diagnoses
Exclusion criteria
* Treatment without pedicle screws
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Proportion of patients in which at least one pedicle screw is not accurately placed (substudy 1) | Periprocedural | Accurate screw placement is defined as a pedicle screw that remains entirely within the cortical boundary of the pedicle, or with up to 2 mm breach of the pedicle wall (corresponds to Gertzbein-Robbins Grade A and B), assessed on a computed tomography. To evaluate screw placement accuracy, we will define a binary per-patient outcome: whether at least one screw is not accurately placed. The planned sample size for this substudy is 75 patients in the robotic-assisted surgery group, and 426 patients in the non-robotic-assisted group, for a total of 501 patients. For this outcome, previously treated cases may be included as specified in the approved protocol. |
| Learning curve (substudy 2) | Periprocedural | To evaluate the learning curve associated with robotic-assisted surgery, we will model operative time as a function of case number. Operative time is expected to decrease with experience, then plateau. We will use mixed-effects piece-wise linear regression with the surgeon as a random effect to estimate the case number at which operative time levels off. The sample size in this substudy is 100 robotic-assisted spine surgeries in each of the 3 centers currently using robotic-assisted spine surgery (Umeå, Örebro, Uppsala), in total 300 surgeries. For this outcome, previously treated cases may be included as specified in the approved protocol. |
| Reoperation rate at 2 years (substudy 3) | From enrolment up until 2 years after surgery | The primary outcome is the occurrence of reoperations of any cause within 2 years from the index surgery. The expected reoperation rate in the non-robotic group is likely to be higher than 3-5% over a 2-year period, and may in the robotic-assisted group be 1% or less. A difference of 2 percentage points or greater is considered clinically meaningful. Power analyses (80% power, alpha 0.05) have been made in two scenarios, with reoperation rates of 3% vs 1%, or 5% vs 3%. We estimate a ratio of 1:6 for robotic-assisted surgery vs navigation-assisted or free hand surgeries. Comparing 3% and 1% reoperation rates, 420 robotic-assisted surgery patients and 2,520 non-robotic surgery patients are needed (yielding a total sample size of 2,940 patients). In case reoperation rates are 5% and 3%, 866 robotic-assisted surgery patients and 5,196 non-robotic surgery patients are needed (yielding a total sample size of 6,062 patients). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Screw placement precision | Periprocedural | We will evaluate screw placement precision as the deviation between preoperative planning and actual placement in robotic-assisted surgery cases. For each screw, linear deviation (at the tip and tail) perpendicular from the planned position, to the actual position, and angular deviation between the planned position and the actual position will be measured. This comparison will be made on an overlay of the preoperative planning made on a preoperative computed tomography, and compared with the computed tomography performed intra- or postoperative for assessment of pedicle screw position |
| Length of stay | Periprocedural | Inhospital stay (days) for the index surgery |
| Time to return to work | From surgery until 2 years after surgery | Time to return to work from the enrolment, which is the time for the index surgery |
| Health economic analysis | From enrollment until the two-year follow-up | — |
| EQ-VAS | At the one-year follow-up | Health related quality of life measured with EQ-VAS (ranges from 0 (worst) to 100 (best)) |
| EQ-5D | At the one-year follow-up | Quality of life assessed with EQ-5D, converted into an index, ranging from around 0 (worst) to 1 (best) |
| Proportion of patients achieving the patient acceptable symptom state (PASS) for EQ-VAS | At the one-year follow-up | PASS EQ-VAS is for elective patients 75 or more, and for non-elective patients 65 or more. EQ-VAS ranges from 0 (worst) to 100 (best) |
| Adverse events- thromboembolic and cardiovascular complications | From enrolment until the 2 year follow-up | Number (proportion) of thromboembolic events and cardiovascular complications will be assessed as secondary safety outcomes. |
| Adverse events- mortality | From enrolment until the 2 year follow-up | Mortality will be assessed as a secondary safety outcome. |
Countries
Sweden
Contacts
CONTACTPaul Gerdhem, MD, PhD
CONTACTLuigi Belcastro, RN
Outcome results
None listed