Surgical Treatment of Adjacent Segment Stenosis

NCT07661199 | Not Yet Recruiting DMC

• 2 other identifiers: STASS-Trial574896382
• Study Type: interventional
• Target: 338
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this clinical trial is to learn whether microdecompression alone is as effective as decompression with extension of fusion surgery in patients with symptomatic adjacent segment stenosis after previous lumbar fusion surgery. The main questions it aims to answer are: Is microdecompression alone non-inferior to decompression with extension of fusion in improving disability 24 months after surgery, as measured by the Oswestry Disability Index (ODI)? Does microdecompression alone result in similar or lower rates of complications, reoperations, pain, and radiological progression compared with decompression and fusion? Researchers will compare microdecompression alone to decompression with extension of lumbar fusion to determine whether the less invasive procedure can achieve similar clinical outcomes while reducing surgical burden and preserving spinal structures. Participants will: Be randomly assigned to one of two treatment groups: microdecompression alone or decompression with extension of lumbar fusion. Undergo the assigned surgical treatment. Attend clinical and radiological follow-up visits at 6, 12, and 24 months after surgery. Complete questionnaires assessing disability, pain, quality of life, sleep quality, and mental health. Undergo routine imaging and clinical examinations to evaluate treatment outcomes and possible complications.

Conditions

Adjacent Segment Disease; Lumbar Spinal Stenosis

Keywords

Adjacent Segment Disease; Adjacent Segment Stenosis; Lumbar Spinal Stenosis

Outcome Measures

Primary Outcomes (1)

• Proportion of Participants Achieving at Least 30% Reduction in Oswestry Disability Index (ODI)

  The primary endpoint is the proportion of participants achieving a reduction of at least 30% in the Oswestry Disability Index (ODI) compared with baseline. The ODI is a validated patient-reported outcome measure assessing disability related to lumbar spine disorders on a scale from 0% to 100%. A reduction of at least 30% is considered clinically meaningful.

  24 months after surgery

Secondary Outcomes (20)

• Pain related disability

  Baseline (before surgery), 6 months after surgery, 12 months after surgery, and 24 months after surgery.

• Leg Pain Intensity at Rest

  Baseline (before surgery), 6 months after surgery, 12 months after surgery, and 24 months after surgery.

• Leg Pain Intensity during Movement

  Baseline (before surgery), 6 months after surgery, 12 months after surgery, and 24 months after surgery.

• Back Pain Intensity at Rest

  Baseline (before surgery), 6 months after surgery, 12 months after surgery, and 24 months after surgery.

• Back Pain Intensity during Movement

  Baseline (before surgery), 6 months after surgery, 12 months after surgery, and 24 months after surgery.

Study Arms (2)

Control

ACTIVE COMPARATOR

Decompression and fusion

Procedure: Microsurgical Decompression with Extension of Fusion

Intervention

ACTIVE COMPARATOR

Mircosurgical decompression only

Procedure: Microsurgical Decompression Alone

Interventions

Microsurgical Decompression with Extension of Fusion PROCEDURE

Participants undergo microsurgical decompression of symptomatic adjacent segment stenosis combined with extension of the existing lumbar fusion.

Control

Microsurgical Decompression Alone PROCEDURE

Participants undergo microsurgical decompression of symptomatic adjacent segment stenosis after previous lumbar fusion surgery without extension of the existing fusion.

Intervention

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age ≥18 years.
• Oswestry Disability Index (ODI) between 30% and 80% at screening.
• Symptomatic adjacent segment stenosis following degenerative lumbar fusion surgery.
• Persistent symptoms despite at least 6 weeks of appropriate conservative treatment.
• Radiological evidence of adjacent segment spinal stenosis on magnetic resonance imaging (MRI).
• Ability to understand the study procedures and complete patient-reported outcome questionnaires.
• Ability to provide written informed consent.

You may not qualify if:

• Adjacent segment kyphosis or scoliosis greater than 10 degrees.
• Screw loosening or pseudarthrosis of the previous fusion construct.
• Known current pregnancy or breastfeeding.
• Acute traumatic spinal injury or fracture.
• Active inflammatory disease of the spine.
• Active neoplastic disease of the spine.
• Contraindication to spinal surgery.
• Inability to provide informed consent or complete study questionnaires.
• Symptoms attributable to spinal stenosis are not the predominant clinical complaint
• Foraminal stenosis grade ≥2 according to the Lee classification.
• Dynamic spondylolisthesis ≥3 mm on flexion-extension radiographs.
• Persons involuntarily detained by judicial or administrative order.

Sponsors & Collaborators

• Charite University, Berlin, Germany: lead

Study Sites (1)

Charité - Universitätsmedizin Berlin

Berlin, State of Berlin, 10117, Germany

Location

MeSH Terms

Conditions

Spinal Stenosis

Condition Hierarchy (Ancestors)

Spinal Diseases; Bone Diseases; Musculoskeletal Diseases

Central Study Contacts

Anton Früh, PD MD M.Sc.

CONTACT

+49 030 450 660 376; anton.frueh@charite.de

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: May 29, 2026
• First Posted: June 22, 2026
• Study Start (Estimated): October 1, 2026
• Primary Completion (Estimated): September 30, 2030
• Study Completion (Estimated): March 1, 2031
• Last Updated: June 22, 2026

Record last verified: 2026-06

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ANALYTIC CODE
• Time Frame: Beginning 12 months following publication of the primary study results and ending 5 years after publication.
• Access Criteria: De-identified individual participant data (IPD) underlying the results reported in publications arising from this study, as well as the study protocol, statistical analysis plan, and analytic code, will be made available to qualified researchers. Access will be granted to investigators who provide a scientifically sound research proposal that is approved by the study steering committee. Requests must be submitted to the study sponsor and should specify the intended use of the data. Data will be shared only after publication of the primary study results and following execution of an appropriate data-sharing agreement. Access will be provided through a secure electronic data transfer system in accordance with applicable data protection regulations.

Locations

DE (1)