The Osteoporotic Fracture Classification-based Scoring System for Treatment Decision in Thoracolumbar Osteoporotic Fractures

The Osteoporotic Fracture Classification-based Scoring System for Treatment Decision in Thoracolumbar Osteoporotic Fractures: An International Multicenter Prospective Study

This is an international multicenter prospective observational study. Patients with radiologically confirmed, symptomatic, single- or multilevel contiguous TL (from T1 to L5) fractures as a result of primary osteoporosis will be recruited from participating clinics/hospitals (ie, study sites). Fractures included are insufficiency fractures (confirmed by magnetic resonance imaging [MRI]) and traumatic fractures (low-energy trauma, confirmed by computed tomography [CT] or MRI).

Study Overview

• Status: Recruiting
• Conditions: Osteoporosis; Osteoporotic Fractures
• Intervention / Treatment: Procedure: Posterior stabilization (pedicle screws)

Detailed Description

This is an international multicenter prospective observational study. Postmenopausal women ≥ 50 years old and men > 60 years old with radiologically confirmed, symptomatic, single- or multilevel contiguous TL (from T1 to L5) fractures as a result of primary osteoporosis will be recruited from participating clinics/hospitals (ie, study sites). Fractures included are insufficiency fractures (confirmed by magnetic resonance imaging [MRI]) and traumatic fractures (low-energy trauma, confirmed by computed tomography [CT] or MRI).

All osteoporotic TL fractures will be classified using the OF classification system (OF 1 to OF 5). Only the most severe fracture will be used to calculate the OF score. The OF score will be subsequently calculated to aid the surgeons' decision making on the initial treatment plan, which is categorized as either nonsurgical or surgical treatment.

To address the primary study objective, depending on whether the treating surgeons' eventual initial treatment decisions agree with the OF score recommendations, patients will be divided into two groups: 1) patients whose initial treatment is in accordance with the OF score recommendations (the Accordance group), and 2) patients whose initial treatment is in discordance with the OF score recommendations (the Discordance group). Accordance refers to 1) when the OF score is > 6, surgical treatment is prescribed by the treating surgeons, 2) when the OF score is < 6, nonsurgical treatment only is prescribed by the treating surgeons, and 3) when the OF score is 6, either surgical or nonsurgical treatment is prescribed (Note: any surgeons' decision is deemed in accordance with the OF score as the system leaves the decision to the surgeons' discretion in this situation).

Accordance/Discordance group assignment is based on the agreement/discrepancy between the eventual treatment and the recommendations from the OF score that is obtained up to Day 0, although OF scores may be calculated at follow-ups (FUs) for subsequent treatment decision making (eg, whether the treatment plan needs to be modified).

Depending on the actual initial treatment assigned to the patients by the treating surgeons, patients will be divided into two groups: 1) patients assigned to receive nonsurgical treatment (the Nonsurgical group), and 2) patients assigned to receive surgery (the Surgical group).

Day 0 refers to the day when the initial treatment is decided and starts (categorized as nonsurgical or surgical treatment). Subsequent FUs will be calculated in reference to Day 0. Patients will be followed up clinically at discharge, 6 weeks, 3 months, 6 months, and 12 months.

The primary outcome of the study is the return to the mobility level before the injury or symptom onset (as reported by the patient). The FU period for the primary endpoint of the study is 3 months (short-term), and 12 months for the secondary endpoints (long-term).

• Study Type: Observational
• Enrollment (Estimated): 648

Contacts and Locations

• Study Contact: Name: Maria C Medina Giner; Phone Number: 0795456120; Email: maria.medinaginer@aofoundation.org
• Study Contact Backup: Name: Felix Thomas Thomas, PhD; Phone Number: +41 79 671 47 98; Email: felix.thomas@aofoundation.org

Study Locations

• Argentina
  • Buenos Aires, Argentina, 1240
    • Not yet recruiting
    • Sanatorio Guemes
    • Contact: Guillermo Ricciardi, MD; Email: guillermoricciardi@gmail.com
• Brazil
  • Curitiba, Brazil, 80050-50
    • Not yet recruiting
    • Cajuru University Hospital
    • Contact: Emiliano Vialle, MD; Email: evialle@hotmail.com
• Chile
  • Santiago, Chile, 5951
    • Not yet recruiting
    • Department of Orthopedic Surgery, Clinica Alemana de Santiago
    • Contact: Ratko Yurac, MD; Email: ryurac@gmail.com
• Egypt
  • Asyut, Egypt, 71526
    • Not yet recruiting
    • Orthopaedic Department, Assiut University Hospitals, Faculty of Medicine
    • Contact: Mohammad El-Sharkawi, MD; Email: sharkoran@aun.edu.eg
• Finland
  • Tampere, Finland, 33521
    • Not yet recruiting
    • Tampere University Hospital
    • Contact: Marko Neva, MD; Email: marko_neva@yahoo.com
• Germany
  • Erlangen, Germany, 91054
    • Not yet recruiting
    • Center for Spinal and Scoliosis Surgery, Malteser Waldkrankenhaus St. Marien
    • Contact: Klaus Schnake, MD; Email: Klaus.Schnake@waldkrankenhaus.de
• India
  • Chandigarh, India, 160 012
    • Not yet recruiting
    • PGIMER - Postgraduate Institute of Medical Education and Research
    • Contact: Vishal Kumar, MD; Email: drkumarvishal@gmail.com
• Japan
  • Tochigi, Japan, 321-0293
    • Not yet recruiting
    • Dokkyo Medical University Hospital
    • Contact: Masahito Takahata, MD; Email: takahiroshm@yahoo.co.jp
• Malaysia
  • George Town, Malaysia, 10450
    • Recruiting
    • Island Hospital Spine Centre
    • Contact: Kim Soon Oh, MD; Email: ohkimsoon@utar.edu.my
• Romania
  • Iași, Romania, 700309
    • Recruiting
    • Spiatlul Clinic De Urgenta, "Profesor Doctor Nicolae Oblu"
    • Contact: Eugen Cezar Popescu, MD; Email: ciepopescu@yahoo.com
• Saudi Arabia
  • Riyāḑ, Saudi Arabia, 11564
    • Recruiting
    • Security Force Hospital
    • Contact: Ahmed Alzahrani, MD; Email: ahmed_alzahrani_4@hotmail.com
• Switzerland
  • Burgdorf, Switzerland, 3400
    • Not yet recruiting
    • Spital Emmental - Orthopädie Sonnenhof
    • Contact: Sebastian Bigdon, MD; Email: sebastian.bigdon@insel.ch
• United Kingdom
  • London, United Kingdom, SE5 9RS
    • Not yet recruiting
    • King's College Hospital
    • Contact: Gordan Grahovac, MD; Email: gordan.grahovac@nhs.net
• United States
  • California
    • San Francisco, California, United States, 94143-0728
      • Not yet recruiting
      • University of California San Francisco (USCF) Department of Orthopaedic Surgery
      • Contact: Ashraf El Naga, MD; Email: ashraf.elnaga@ucsf.edu
  • Pennsylvania
    • Philadelphia, Pennsylvania, United States, 19107-4216
      • Not yet recruiting
      • Thomas Jefferson University Hospital
      • Contact: Alexander R Vaccaro, MD; Email: alex.vaccaro@rothmaninstitute.com

Participation Criteria

Eligibility Criteria

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

• Sampling Method: Non-Probability Sample

Study Population

Postmenopausal women ≥ 50 years old or men > 60 years old

Description

Inclusion Criteria:

• Postmenopausal women ≥ 50 years old or men > 60 years old

  o Menopause refers to amenorrhea for 1 complete year.

• Radiologically confirmed new diagnosis of symptomatic, single or multilevel TL (from T1 to L5) fractures, ie, the index fracture(s).

  • In case of a multilevel fracture, the fracture must be contiguous.
  • The index fracture is confirmed by MRI as an insufficiency (or fragility) fracture or is confirmed by CT or MRI as traumatic fracture (low-energy trauma)

• The index fracture(s) is a result of primary osteoporosis. Diagnosis of primary osteoporosis is based on any of the followings in the absence of causes for secondary osteoporosis (such as long-term use of steroids, rheumatoid arthritis, type 1 diabetes mellitus [DM], and other metabolic bone disorders [eg, rickets/osteomalacia, Paget's disease, osteogenesis imperfecta, and primary hyperparathyroidism]) [13-15]:

  • A T-score ≤ -2.5 in the lumbar spine, femoral neck, total hip, or 1/3 radius
  • Presence of fragility fracture (either a previous fragility fracture or the index fracture is a fragility fracture). Fragility fractures are fractures due to no or low-energy trauma, eg, slips, trips, or falls from less than double the body height, and heavy lifting.

• The index osteoporotic TL fracture being classified based on the OF Classification from OF 1 to OF 5:

  • OF 1: No deformation (vertebral body edema on MRI using short tau inversion recovery [STIR] sequence)
  • OF 2: Deformation of one endplate
  • OF 3: Deformation of one endplate with distinct posterior wall involvement
  • OF 4: Deformation of both endplates with/without posterior wall involvement
  • OF 5: Injuries with anterior or posterior tension band failure
• Ability to provide informed consent according to the EC/IRB defined and approved procedures

Exclusion Criteria:

• Patients with spinal tumors
• Patients with concomitant cervical fractures
• Patients showing any signs of spinal infections
• Patients with fractures due to high-energy or high-impact trauma, eg, a fall from double the body height or higher, motor vehicle accident with > 100 km/h in cars with airbags, or motor vehicle accident > 50 km/h without airbags, polytrauma
• Patients with concomitant fracture in the pelvis, upper extremities, and/or lower extremities which could affect the main study outcomes (specifically, patient mobility and pain)
• Patients for whom no FUs are possible
• Previous instrumented surgery in the affected spine levels
• Patients with single-level fracture or contiguous multilevel fracture adjacent to previous instrumented surgery
• Patients who are mentally impaired and therefore not able to adhere to the study procedures and data collection
• Patients who are bedridden before the index fracture
• Recent history of substance abuse (ie, recreational drugs and alcohol) that would preclude reliable assessments
• Participation in any other medical device or medicinal product study within the previous month that could influence the results of the present study

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
OF score accordance group; Initial treatment decision in accordance with the OF score recommendations	Procedure: Posterior stabilization (pedicle screws); Any other type of solely vertebral augmentation (stents, etc.), specify; Posterior stabilization (pedicle screws); Posterior stabilization (pedicle screws) with kyphoplasty/vertebroplasty; Posterior stabilization (pedicle screws) with screw augmentation; Posterior stabilization (pedicle screws) with screw augmentation and kyphoplasty/vertebroplasty; Posterior stabilization (pedicle screws) with vertebral osteotomy (pedicle subtraction osteotomy or similar); Combined posterior and anterior stabilization; Other Names: Vertebroplasty; Kyphoplasty
OF score discordance group; Initial treatment decision in discordance with the OF score recommendations	Procedure: Posterior stabilization (pedicle screws); Any other type of solely vertebral augmentation (stents, etc.), specify; Posterior stabilization (pedicle screws); Posterior stabilization (pedicle screws) with kyphoplasty/vertebroplasty; Posterior stabilization (pedicle screws) with screw augmentation; Posterior stabilization (pedicle screws) with screw augmentation and kyphoplasty/vertebroplasty; Posterior stabilization (pedicle screws) with vertebral osteotomy (pedicle subtraction osteotomy or similar); Combined posterior and anterior stabilization; Other Names: Vertebroplasty; Kyphoplasty

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Return to mobility	Determination in patients with symptomatic osteoporotic TL fractures whether an initial treatment adhering to the OF score recommendations (the Accordance group) generates better short-term patient outcomes regarding time to return to mobility level before injury or symptom onset within 3 months after treatment compared to an initial treatment decision not adhering to the OF score recommendations (the Discordance group). The primary outcome of the study is return to the mobility level. Patients will be instructed to evaluate their overall mobility level in reference to their pre-injury or pre-symptom mobility status. This primary outcome will be reported by the patient and measured on a continuous scale of 0 to 100 (0 = no return at all, 100 = full return). Primary endpoint of the study is the time (days) to return of pre-injury or pre-symptom mobility level within 3 months after Day 0. Threshold of returning is defined as ≥ 80 on the continuous scale.	From day of treatment to the end of the first 3 months after treatment.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Comparison of the extent of return to mobility	To compare the extend of return (measured on a continuous scale of 0 to 100, with 0 representing no return at all and 100 representing full return) at 3 months (short-term outcome) and 12 months (long-term outcome) between the Accordance and the Discordance group.	3 months post-operative and 12-months postoperative
Comparison of clinical outcome	To compare the clinical outcome at 3 and 12 months between the Accordance and the Discordance groups, between patients whose initial and subsequent treatment decisions adhere to the OF score recommendations and those whose treatment decisions do not completely adhere to the OF score recommendations, between patients with symptomatic osteoporotic TL fracture treated non-surgically and those treated surgically and between nonsurgical and surgical treatments (as determined by a blinded expert group). Clinical outcome defined as any of the following events occurring: New or adjacent vertebral fracture, crossover to surgery or additional surgery, use of analgesic, fracture- or treatment-related adverse events.	3 months post-operative and 12-months postoperative
Comparison of the proportion return to mobility	To compare the proportion of patients returning to pre-injury mobility level at 3 and 12 months between the Accordance and the Discordance groups, between patients whose initial and subsequent treatment decisions adhere to the OF score recommendations and those whose treatment decisions do not completely adhere to the OF score recommendations, between patients with symptomatic osteoporotic TL fracture treated non-surgically and those treated surgically and between nonsurgical and surgical treatments (as determined by a blinded expert group).	3 months post-operative and 12-months postoperative
Comparison of Timed Up & Go test	To compare timed Up & Go in seconds at 3 and 12 months between the Accordance and the Discordance groups, between patients whose initial and subsequent treatment decisions adhere to the OF score recommendations and those whose treatment decisions do not completely adhere to the OF score recommendations, between patients with symptomatic osteoporotic TL fracture treated non-surgically and those treated surgically and between nonsurgical and surgical treatments (as determined by a blinded expert group).	3 months post-operative and 12-months postoperative
Comparison of daily activities	To compare the score of the Barthel Index (ranging from 0 to 100, with higher scores indicating greater functional independence) at 3 and 12 months between the Accordance and the Discordance groups, between patients whose initial and subsequent treatment decisions adhere to the OF score recommendations and those whose treatment decisions do not completely adhere to the OF score recommendations, between patients with symptomatic osteoporotic TL fracture treated non-surgically and those treated surgically and between nonsurgical and surgical treatments (as determined by a blinded expert group).	3 months post-operative and 12-months postoperative
Comparison of pain NRS (Numeric Rate Scale)	To compare the score of pain Numeric Rate Scale (ranging from 0 to 10, with 0 representing no pain and 10 the worst imaginable pain) at 3 and 12 months between the Accordance and the Discordance groups, between patients whose initial and subsequent treatment decisions adhere to the OF score recommendations and those whose treatment decisions do not completely adhere to the OF score recommendations, between patients with symptomatic osteoporotic TL fracture treated non-surgically and those treated surgically and between nonsurgical and surgical treatments (as determined by a blinded expert group).	3 months post-operative and 12-months postoperative
Comparison of ODI (Oswestry Disability Index)	To compare the score of ODI (ranging from 0 to 100%, with higher scores indicating greater disability) at 3 and 12 months between the Accordance and the Discordance groups, between patients whose initial and subsequent treatment decisions adhere to the OF score recommendations and those whose treatment decisions do not completely adhere to the OF score recommendations, between patients with symptomatic osteoporotic TL fracture treated non-surgically and those treated surgically and between nonsurgical and surgical treatments (as determined by a blinded expert group).	3 months post-operative and 12-months postoperative
Comparison of quality of live	To compare the score of EQ-5D-5L (ranging from 0 to 1, with 0 representing death and 1 perfect health) at 3 and 12 months between the Accordance and the Discordance groups, between patients whose initial and subsequent treatment decisions adhere to the OF score recommendations and those whose treatment decisions do not completely adhere to the OF score recommendations, between patients with symptomatic osteoporotic TL fracture treated non-surgically and those treated surgically and between nonsurgical and surgical treatments (as determined by a blinded expert group).	3 months post-operative and 12-months postoperative
Comparison of the AO Spine PROST	To compare the score of AO Spine PROST (ranging from 0 to 100, with higher score indicating better recovery of functional level before trauma) at 3 and 12 months between the Accordance and the Discordance groups, between patients whose initial and subsequent treatment decisions adhere to the OF score recommendations and those whose treatment decisions do not completely adhere to the OF score recommendations, between patients with symptomatic osteoporotic TL fracture treated non-surgically and those treated surgically and between nonsurgical and surgical treatments (as determined by a blinded expert group).	3 months post-operative and 12-months postoperative
Comparison of the overall satisfaction	To compare the proportion of overall satisfaction (measured on a 7-point Likert scale (Extremely satisfied, Very satisfied, Somewhat satisfied, Mixed, Somewhat dissatisfied, Very dissatisfied, Extremely dissatisfied) of patients at 3 and 12 months between the Accordance and the Discordance groups, between patients whose initial and subsequent treatment decisions adhere to the OF score recommendations and those whose treatment decisions do not completely adhere to the OF score recommendations, between patients with symptomatic osteoporotic TL fracture treated non-surgically and those treated surgically and between nonsurgical and surgical treatments (as determined by a blinded expert group).	3 months post-operative and 12-months postoperative
Complications-determination in relation to surgery	To determine the rate and type of complications in relation to the type of surgery performed	1 year post-operative
Complications-determination in relation to OF subtype	To determine the rate and type of complications in relation to the OF subtype	1 year post-operative
Determination of type of treatment	To determine the type of treatment in relation to the OF subtype	1 year post-operative
Determination of rate and type of surgical treatment	To determine the type of surgical treatment in relation to the OF subtype. The surgery types are: Kyphoplasty; Vertebroplasty; Any other type of solely vertebral augmentation (stents, etc.), specify; Posterior stabilization (pedicle screws); Posterior stabilization (pedicle screws) with kyphoplasty/vertebroplasty; Posterior stabilization (pedicle screws) with screw augmentation; Posterior stabilization (pedicle screws) with screw augmentation and kyphoplasty/vertebroplasty; Posterior stabilization (pedicle screws) with vertebral osteotomy (pedicle subtraction osteotomy or similar); Combined posterior and anterior stabilization, if yes:; Open surgery; Percutaneous/minimal-invasive surgery; Delete "rate" from 10 only keeping type and list them from above	1 year post-operative
Proportion between surgery after initial non-surgery treatment	To determine the proportion of patients who underwent surgery after initial nonsurgical treatment (crossover to surgery).	1 year post-operative
Agreement between OF classification and investigators	To determine the proportion of agreement in the OF classification (from OF 1 to OF 5 categories) made by the site investigators and a blinded expert panel. OF 1: No deformation (vertebral body edema in MRI-STIR) OF 2: Deformation of one endplate without or with only minor posterior wall involvement OF 3: Deformation of one endplate with distinct posterior wall involvement OF 4: Deformation of both endplates with or without posterior wall involvement OF 5: Injuries with anterior or posterior tension band failure	1 year post-operative
Validation of AO PROST	To validate the AO Spine Patient-Reported Outcome Spine Trauma (PROST) in terms of interpretability, internal consistency, and responsiveness in patients with symptomatic osteoporotic TL fractures. The AO Spine PROST consists of 19 questions on broad aspects of functioning. Each item has a 0-100 scale, with 0 indicating no function at all and 100 the functional level before trauma. Total score ranges from 0 to 100, with higher score indicating better recovery of functional level before trauma.	1 year post-operative
Health economic analyses	To perform health economic analyses to investigate the cost-effectiveness/cost-utility of a) comparing non-surgical to surgical treatment and b) the effect of adhering to the OF score for treating patients with osteoporotic TL fractures compared with not adhering to the OF score. The cost-effectiveness will be evaluated using the incremental cost effectiveness ratio.	1 year post-operative
Comparison of return to mobility (categorical scale)	To compare the proportion (in percentage) of patients returning to mobility level (measured in 4 categories: Not at all returned, Partially returned with major restrictions, Partially returned with minor restrictions, and Fully returned) at 3 months (short-term outcome) and 12 months (long-term outcome) between the Accordance and the Discordance group.	At all predefined visits from discharge to 12months post treatment

Collaborators and Investigators

• Sponsor: AO Foundation, AO Spine
• Investigators: Principal Investigator: Klaus Schnake, MD, Center for Spinal and Scoliosis Surgery

Study record dates

Study Major Dates

• Study Start (Actual): March 19, 2026
• Primary Completion (Estimated): December 1, 2028
• Study Completion (Estimated): December 1, 2030

Study Registration Dates

• First Submitted: May 2, 2025
• First Submitted That Met QC Criteria: June 16, 2025
• First Posted (Actual): June 18, 2025

Study Record Updates

• Last Update Posted (Actual): May 13, 2026
• Last Update Submitted That Met QC Criteria: May 11, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Bone Diseases; Musculoskeletal Diseases; Wounds and Injuries; Metabolic Diseases; Fractures, Bone; Bone Diseases, Metabolic; Nutritional and Metabolic Diseases; Osteoporosis; Osteoporotic Fractures; Therapeutics; Surgical Procedures, Operative; Orthopedic Fixation Devices; Orthopedic Equipment; Surgical Equipment; Equipment and Supplies; Surgical Fixation Devices; Prostheses and Implants; Orthopedic Procedures; Cementoplasty; Internal Fixators; Bone Screws; Vertebroplasty; Kyphoplasty; Pedicle Screws
• Other Study ID Numbers: TL-OF

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

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