Robotic-Assisted Pedicle Screw Placement in Spine Surgery (ROBOTICSS)

ROBOTICSS - Robotic-Assisted Pedicle Screw Placement in Spine Surgery: A Multicenter Prospective Observational Study

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.

Study Overview

• Status: Recruiting
• Conditions: Pedicle Screw Fixation of Spine
• Intervention / Treatment: Device: Robotic-assisted pedicle screw placement

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.

• Study Type: Observational
• Enrollment (Estimated): 7200

Contacts and Locations

• Study Contact: Name: Paul Gerdhem, MD, PhD; Phone Number: +46(0)186110000; Email: paul.gerdhem@uu.se
• Study Contact Backup: Name: Luigi Belcastro, RN; Phone Number: +46(0)184710000; Email: luigi.belcastro@uu.se

Study Locations

• Sweden
  • Gothenburg, Sweden
    • Recruiting
    • Sahlgrenska University Hospital
    • Contact: Catharina Parai, MD, PhD; Email: catharina.parai@vgregion.se
  • Jönköping, Sweden
    • Recruiting
    • Ryhov Hospital
    • Contact: Håkan Löfgren, MD, PhD; Phone Number: +4610241 00 00; Email: hakan.lofgren@regionjonkoping.se
  • Kalmar, Sweden
    • Recruiting
    • Länssjukhuset Kalmar
    • Contact: Erik Vestberg, MD; Phone Number: +4610358 00 00; Email: erik.vestberg@regionkalmar.se
  • Linköping, Sweden
    • Recruiting
    • University Hospital Linköping
    • Contact: Ludvig Vavruch, MD, PhD; Phone Number: +4610103 47; Email: ludvig.vavruch@regionostergotland.se
  • Stockholm, Sweden
    • Recruiting
    • Karolinska University Hospital
    • Contact: Anastasios Charalampidis, MD, PhD; Phone Number: +46812370000; Email: anastasios.charalampidis@regionstockholm.se
  • Stockholm, Sweden
    • Recruiting
    • South General Hospital (Södersjukhuset)
    • Contact: Ted Eneqvist, MD, PhD; Phone Number: +468123 610 00; Email: ted.eneqvist@regionstockholm.se
  • Umeå, Sweden
    • Recruiting
    • Umea University Hospital
    • Contact: Lukas Bobinski, MD, PhD; Phone Number: +4690785 00 00; Email: lukas.bobinski@umu.se
  • Uppsala, Sweden, 75185
    • Recruiting
    • Uppsala University Hospital
    • Contact: Paul Gerdhem, MD, PhD; Phone Number: +46(0)186110000; Email: paul.gerdhem@uu.se
    • Contact: Luigi Belcastro, RN; Phone Number: +46(0)184710000; Email: luigi.belcastro@uu.se
    • Principal Investigator: Nikos Schizas, MD, PhD
  • Örebro, Sweden
    • Recruiting
    • Orebro University Hospital
    • Contact: Anders Joelson, MD, PhD; Email: anders.joelson@regionorebrolan.se
    • Contact: Gauti Sigmundsson, MD, PhD; Phone Number: +461960210; Email: freyr.sigmundsson@regionorebrolan.se

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Swedish residents undergoing spine surgery in Sweden

Description

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

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Robotic-assisted pedicle screw placement; Robotic-assisted pedicle screw placement using commercially available robotic systems	Device: Robotic-assisted pedicle screw placement; Robotic-assisted pedicle screw placement using commercially available robotic systems
Conventional pedicle screw placement; Conventional pedicle screw placement using navigation-assisted or freehand techniques

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Proportion of patients in which at least one pedicle screw is not accurately placed (substudy 1)	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.	Periprocedural
Learning curve (substudy 2)	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.	Periprocedural
Reoperation rate at 2 years (substudy 3)	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).	From enrolment up until 2 years after surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Screw placement precision	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	Periprocedural
Length of stay	Inhospital stay (days) for the index surgery	Periprocedural
Time to return to work	Time to return to work from the enrolment, which is the time for the index surgery	From surgery until 2 years after surgery
Health economic analysis		From enrollment until the two-year follow-up
EQ-VAS	Health related quality of life measured with EQ-VAS (ranges from 0 (worst) to 100 (best))	At the one-year follow-up
EQ-5D	Quality of life assessed with EQ-5D, converted into an index, ranging from around 0 (worst) to 1 (best)	At the one-year follow-up
Proportion of patients achieving the patient acceptable symptom state (PASS) for EQ-VAS	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)	At the one-year follow-up
Adverse events- thromboembolic and cardiovascular complications	Number (proportion) of thromboembolic events and cardiovascular complications will be assessed as secondary safety outcomes.	From enrolment until the 2 year follow-up
Adverse events- mortality	Mortality will be assessed as a secondary safety outcome.	From enrolment until the 2 year follow-up

Collaborators and Investigators

• Sponsor: Uppsala University
• Collaborators: Karolinska University Hospital; Karolinska Institutet; Lund University; Göteborg University; Umeå University; University Hospital, Linkoeping; Örebro University, Sweden; Skane University Hospital; Uppsala University Hospital; Ôrebro University Hospital; Umeå University Hospital; Sahlgrenska University Hospital; Södersjukhuset (Stockholm South General Hospital); University of Linköping; Länssjukhuset Ryhov; Länssjukhuset Kalmar

Study record dates

Study Major Dates

• Study Start (Actual): February 2, 2026
• Primary Completion (Estimated): February 2, 2032
• Study Completion (Estimated): February 2, 2035

Study Registration Dates

• First Submitted: February 25, 2026
• First Submitted That Met QC Criteria: March 4, 2026
• First Posted (Actual): March 10, 2026

Study Record Updates

• Last Update Posted (Actual): March 10, 2026
• Last Update Submitted That Met QC Criteria: March 4, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Surgery; Spine; Pedicle screws; Surgical technique; Robotic assisted; Spinal implants; Spinal disorder
• Additional Relevant MeSH Terms: Bone Diseases; Musculoskeletal Diseases; Spinal Diseases
• Other Study ID Numbers: ROBOTICSS, protocol vers.1.01

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

IPD Plan Description

Individual participant data underlying the results reported in this study will not be publicly shared. Under Swedish law, registry-based health data are protected by the General Data Protection Regulation (GDPR). Sharing of individual-level data requires a valid ethical approval from the Swedish Ethical Review Authority and a formal data-sharing agreement with the data-holding authority.

Researchers who obtain appropriate ethical approval and fulfill Swedish legal requirements may request access to relevant data from the responsible data controller. Such requests will be evaluated in accordance with national legislation and institutional policies.

The study investigators will share aggregated results and statistical code upon reasonable request.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No