Cervical Movement Control Before and After Anterior Cervical Discectomy and Fusion (MOVE-ACDF)

Early Changes in Dynamic Cervical Movement Control Following Anterior Cervical Discectomy and Fusion: A Prospective Controlled Longitudinal Study

Degenerative cervical disc disease can cause neck pain, nerve symptoms, dizziness, and problems with balance and head movement control. The neck contains many sensory receptors that provide information about head position and movement to the brain. When cervical discs degenerate or compress nearby structures, this sensory communication may be disrupted. As a result, patients may experience reduced accuracy and coordination of head movements.

Anterior cervical discectomy and fusion (ACDF) is a standard surgical procedure used to relieve nerve or spinal cord compression caused by cervical disc disease. The procedure is effective in reducing pain and neurological symptoms. However, it is not well understood whether ACDF also improves the way the neck and nervous system work together to control head movement.

The purpose of this study is to evaluate early changes in cervical movement control after ACDF. Patients scheduled for ACDF will be assessed before surgery and again one week after surgery. A group of healthy participants without neck pain will be assessed at the same time interval for comparison.

Cervical movement control will be measured using a computer-based head-tracking task. During this task, participants follow a moving target on a screen using controlled head movements. The system records measures of tracking accuracy and timing.

The primary research question is whether ACDF results in measurable short-term improvements in objective cervical movement control compared with healthy individuals over the same time period.

It is hypothesized that patients undergoing ACDF will demonstrate improvement in specific movement-control measures after surgery. However, broader patterns of movement-control impairment may not fully normalize in the early postoperative period.

The results of this study may improve understanding of how cervical spine surgery affects sensorimotor function and may help inform postoperative rehabilitation strategies.

Study Overview

• Status: Recruiting
• Conditions: Intervertebral Disc Displacement; Cervical Vertebral Disc Degeneration
• Intervention / Treatment: Procedure: Anterior Cervical Discectomy and Fusion

Detailed Description

Detailed Description Degenerative cervical disc disease is commonly associated with neck pain and neurological symptoms. In addition to these clinical manifestations, increasing evidence indicates that cervical spine pathology may impair cervical sensorimotor control. The cervical spine contains a high density of muscle spindles and joint mechanoreceptors that provide afferent information about head position and movement. This sensory input is integrated with visual and vestibular systems to regulate head-neck coordination and postural stability. Structural degeneration or neural compression may disrupt afferent signaling and alter this integration, potentially contributing to impaired movement accuracy, dizziness, or imbalance.

Anterior cervical discectomy and fusion (ACDF) is a standard surgical procedure used to relieve nerve root or spinal cord compression caused by cervical disc herniation when conservative treatment fails. While ACDF has demonstrated effectiveness in reducing pain and neurological deficits, its effects on objective cervical movement-control measures remain insufficiently characterized.

The RECAL-ACDF study is a prospective controlled longitudinal investigation designed to evaluate early changes in dynamic cervical movement control following ACDF. The study compares patients undergoing ACDF with time-matched healthy control participants assessed over the same time interval.

Study Design

Participants in the surgical group will be assessed at two time points:

• Preoperative baseline (within one week prior to surgery)
• One week postoperatively Healthy control participants will be assessed at two time points separated by a comparable interval.

The study uses a parallel-group, non-randomized design. The primary purpose is mechanistic evaluation of sensorimotor function.

Assessment of Cervical Movement Control Cervical movement control will be assessed using a validated dynamic head-tracking task (Butterfly test) implemented through the NeckSmart system (NeckCare™, Reykjavik, Iceland). The system uses a head-mounted inertial measurement unit (IMU) to record head movements while participants track an unpredictably moving visual target displayed on a computer screen.

The task includes three predefined difficulty levels (easy, medium, difficult), characterized by increasing target velocity and trajectory complexity. For each difficulty level, three trials will be performed.

The following outcome measures will be derived:

• Time-on-target (percentage of total trial time within the target zone)
• Undershoot (percentage of total trial time behind the target)
• Overshoot (percentage of total trial time in front of the target)
• Amplitude accuracy (mean spatial deviation between target and head-controlled cursor, expressed in millimeters)

Mean values across repetitions will be used for statistical analyses.

Primary Objective To determine whether ACDF results in short-term improvements in dynamic cervical movement control compared with healthy controls over the same time period.

The primary outcome measure is the change in time-on-target at medium difficulty (ToT_m) from baseline to one week postoperatively.

Secondary Objectives

• To evaluate changes in additional movement-control parameters across difficulty levels.
• To assess change in amplitude accuracy at difficult level (AA_d).
• To determine whether surgery is associated with redistribution across predefined multidimensional movement-control impairment clusters (four ordinal severity levels).
• To explore whether parameter-level improvements correspond to broader changes in impairment phenotype.

Cluster allocation (severity levels 1-4) will be determined using a previously established multidimensional classification framework based on standardized movement-control parameters.

Hypothesis It is hypothesized that patients undergoing ACDF will demonstrate measurable improvement in selected dynamic movement-control parameters one week after surgery. However, categorical redistribution across multidimensional impairment clusters may not occur in the early postoperative period.

This study conceptualizes postoperative recovery as an early sensorimotor recalibration process rather than immediate normalization of movement-control phenotype.

Statistical Approach The primary analysis will compare change scores (postoperative minus preoperative values) between the surgical and control groups. Appropriate parametric or nonparametric statistical tests will be applied depending on data distribution. Multiple comparisons will be controlled using the Holm-Bonferroni procedure.

Cluster allocation (ordinal severity levels 1-4) will be analyzed using proportional odds regression models with subject-level clustering to account for repeated measurements.

Clinical Relevance This study aims to clarify whether structural decompression of the cervical spine is associated with early recalibration of cervical sensorimotor control. Improved understanding of postoperative sensorimotor changes may inform development of targeted rehabilitation strategies following ACDF.

• Study Type: Interventional
• Enrollment (Estimated): 30
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Ziva dr. Majcen Rosker, PhD; Phone Number: 00386 51267383; Email: Ziva.MajcenRosker@fsp.uni-lj.si
• Study Contact Backup: Name: Miha dr. Vodicar, PhD

Study Locations

• Slovenia
  • Ljubljana, Slovenia, 3000
    • Recruiting
    • Faculty of Sport, University of Ljubljana
    • Contact: Ziva dr. Majcen Rosker, PhD; Phone Number: 0038516267383; Email: Ziva.MajcenRosker@fsp.uni-lj.si

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria

Surgical group:

• Age 18 to 65 years
• Clinical diagnosis of cervical disc pathology at one segment level (e.g., cervical disc herniation or degenerative disc disease)
• Scheduled to undergo anterior cervical discectomy and fusion (ACDF) as part of standard clinical care
• Ability to understand study procedures and provide written informed consent

Non-Surgical neck pain group:

• Age 18 to 65 years
• Clinical diagnosis of neck pain associated with cervical disc pathology
• Not undergoing surgical treatment during the study period
• Ability to understand study procedures and provide written informed consent

Exclusion Criteria:

• Prior cervical spine surgery
• Diagnosed neurological disorders unrelated to cervical disc pathology (e.g., multiple sclerosis, Parkinson's disease, stroke)
• Known vestibular disorders affecting balance
• Severe uncorrected visual impairment
• Acute musculoskeletal injury of the neck or upper limb unrelated to the primary cervical condition
• Inability to perform the head-tracking task
• Cognitive impairment preventing informed consent

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Anterior Cervical Discectomy and Fusion (ACDF); Participants diagnosed with cervical disc pathology and scheduled to undergo anterior cervical discectomy and fusion (ACDF) as part of standard clinical care. Cervical movement control will be assessed within one week prior to surgery and again one week after surgery using a standardized dynamic head-tracking task. Changes in movement-control parameters will be analyzed to evaluate early postoperative sensorimotor changes.	Procedure: Anterior Cervical Discectomy and Fusion; Anterior cervical discectomy and fusion (ACDF) is a surgical procedure performed under general anesthesia to treat cervical disc herniation or degenerative disc disease causing nerve root or spinal cord compression. The procedure involves an anterior approach to the cervical spine, removal of the affected intervertebral disc (discectomy), decompression of neural structures, and placement of an interbody graft or cage with or without anterior plate fixation to achieve segmental fusion. The specific surgical technique and implant selection are determined by the treating spine surgeon according to standard clinical practice.
No Intervention: Non-Surgical Neck Pain Group; Participants diagnosed with neck pain who are not undergoing surgical treatment will serve as the comparison group. These participants will be assessed at two time points separated by a comparable interval to the surgical group. Cervical movement control will be evaluated using the same standardized dynamic head-tracking task. No surgical intervention will be performed during the study period.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change From Baseline in Time-on-Target at Medium Difficulty During Dynamic Cervical Head Tracking at 1 Week	Time-on-target is defined as the percentage of total trial time during which the head-controlled cursor remains within a predefined target zone while following an unpredictably moving visual target on a computer screen. Head motion is recorded using a head-mounted inertial measurement unit during a standardized dynamic tracking task. The medium difficulty level involves predefined target speed and trajectory complexity. Values range from 0% to 100%, with higher percentages indicating better tracking accuracy and movement control. Change from baseline to one week postoperatively will be calculated for analysis.	Baseline (within 1 week prior to surgery) and 1 week after surgery
Change From Baseline in Amplitude Accuracy During Dynamic Cervical Head Tracking at 1 Week	Amplitude accuracy is defined as the mean spatial deviation, expressed in millimeters (mm), between a moving visual target and the head-controlled cursor during a standardized dynamic head-tracking task. Head motion is recorded using a head-mounted inertial measurement unit. Values are continuous and expressed in millimeters, with lower values indicating better tracking precision and movement control. Change from baseline to one week postoperatively will be calculated for analysis.	Baseline (within 1 week prior to surgery) and 1 week after surgery
Change From Baseline in Undershoot During Dynamic Cervical Head Tracking at 1 Week	Undershoot is defined as the percentage of total trial time during which the head-controlled cursor remains behind the moving visual target while performing a standardized dynamic head-tracking task. Head motion is recorded using a head-mounted inertial measurement unit. Values range from 0% to 100%, with lower percentages indicating better tracking performance and improved temporal control. Change from baseline to one week postoperatively will be calculated for analysis.	Baseline (within 1 week prior to surgery) and 1 week after surgery
Change From Baseline in Overshoot During Dynamic Cervical Head Tracking at 1 Week	Overshoot is defined as the percentage of total trial time during which the head-controlled cursor moves ahead of the moving visual target during a standardized dynamic head-tracking task. Head motion is recorded using a head-mounted inertial measurement unit. Values range from 0% to 100%, with lower percentages indicating better tracking precision and movement regulation. Change from baseline to one week postoperatively will be calculated for analysis.	Baseline (within 1 week prior to surgery) and 1 week after surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change From Baseline in Movement-Control Impairment Cluster Classification at 1 Week	Cluster classification represents an ordinal movement-control impairment category derived from multiple dynamic head-tracking parameters. Participants are assigned to one of four predefined severity levels (Cluster 1-4) using a standardized multidimensional classification framework based on tracking accuracy and timing variables. Cluster 1 indicates least impairment and Cluster 4 indicates greatest impairment. Change from baseline to one week postoperatively will be evaluated to determine whether participants shift to a lower or higher impairment category.	Baseline (within 1 week prior to surgery) and 1 week after surgery

Collaborators and Investigators

• Sponsor: University of Ljubljana
• Collaborators: University Medical Centre Ljubljana
• Investigators: Principal Investigator: Ziva Majcen Rosker, PhD, Faculty of Sport, University of Ljubljana

Publications and helpful links

General Publications

• Zheng, H.-L., et al. (2022). ACDF to treat cervical instability with vertigo and dizziness. Frontiers in Surgery, 9, 1047504.
• Yang, L., et al. (2017). Mechanoreceptors in diseased cervical intervertebral disc and vertigo. Spine, 42(8), 540-546.
• Wrisley, D. M., et al. (2000). Cervicogenic dizziness: A review of diagnosis and treatment. J Orthop Sports Phys Ther, 30(12), 755-766.*
• Treleaven, J. (2008). Sensorimotor disturbances in neck disorders-Part 2. Manual Therapy, 13(3), 266-275.
• Takayama, H., et al. (2005). Proprioceptive recovery of patients with cervical myelopathy after surgical decompression. Spine, 30(9), 1039-1044.
• Peng, B. (2018). Cervical vertigo: Historical reviews and advances. World Neurosurgery, 109, 347-350.
• Mendel, T., Wink, C. S., & Zimny, M. L. (1992). Neural elements in human cervical intervertebral discs. Spine, 17(2), 132-135.
• Majcen Rosker, Z., Vodicar, M., & Kristjansson, E. (2022). Altered oculomotor control during smooth pursuit neck torsion test. Int J Environ Res Public Health, 19(7).*
• Majcen Rosker, Z., & Rosker, J. (2024). Cervicocephalic kinaesthesia reveals novel subgroups of motor control impairments in patients with neck pain. Scientific Reports, 14, 8383.
• Majcen Rosker, Z., Kristjansson, E., & Vodicar, M. (2023). Detection of cervical-driven sensorimotor dysfunction in concussion patients. Gait & Posture, 101, 21-27.
• Magnusson, M., & Malmström, E.-M. (2016). The conundrum of cervicogenic dizziness. Handbook of Clinical Neurology, 137, 365-369.
• Liu, T.-H., Liu, Y.-Q., & Peng, B.-G. (2021). Cervical intervertebral disc degeneration and dizziness. World Journal of Clinical Cases, 9(9), 2146-2152.*
• Kristjansson, E., & Treleaven, J. (2009). Sensorimotor function and dizziness in neck pain: Implications for assessment and management. J Orthop Sports Phys Ther, 39(5).
• Cloward, R. B. (1958). The anterior approach for removal of ruptured cervical disks. Journal of Neurosurgery, 15(6). PMID: 13585189
• Boyd-Clark, L. C., Briggs, C. A., & Galea, M. P. (2002). Muscle spindle distribution, morphology, and density in longus colli and multifidus muscles of the cervical spine. Spine, 27(7), 694-701. PMID: 11923660
• Bogduk, N., & Govind, J. (2009). Cervicogenic headache: An assessment of the evidence on clinical diagnosis, invasive tests, and treatment. The Lancet Neurology, 8(10), 959-968.

Study record dates

Study Major Dates

• Study Start (Estimated): February 20, 2026
• Primary Completion (Estimated): March 16, 2026
• Study Completion (Estimated): March 30, 2026

Study Registration Dates

• First Submitted: February 13, 2026
• First Submitted That Met QC Criteria: February 13, 2026
• First Posted (Actual): February 23, 2026

Study Record Updates

• Last Update Posted (Actual): February 23, 2026
• Last Update Submitted That Met QC Criteria: February 13, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: Anterior Cervical Discectomy and Fusion; Cervical Spine Surgery; Postoperative Recovery; Movement Control; Cervical Sensorimotor Control; Cervicocephalic Kinaesthesia; Head and neck movement control test; Neck Proprioception
• Additional Relevant MeSH Terms: Bone Diseases; Musculoskeletal Diseases; Pathological Conditions, Anatomical; Spinal Diseases; Hernia; Pathological Conditions, Signs and Symptoms; Intervertebral Disc Displacement; Genetic Phenomena; Recombination, Genetic; Gene Fusion
• Other Study ID Numbers: FS-UL-CDISECT-2026-01

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data collected in this study will not be made publicly available. The sample size is relatively small and includes patients treated at a single clinical center, which may increase the risk of indirect participant identification despite de-identification procedures. Additionally, the dataset includes detailed movement-control performance variables and clinical characteristics that could potentially allow re-identification when combined with other publicly available information. Data were collected under informed consent and ethics approval that did not include provisions for public sharing of individual-level data. Aggregate results will be reported in scientific publications to ensure transparency while maintaining participant confidentiality.

Drug and device information, study documents

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