Longitudinal Changes in Spinopelvic Alignment and Sagittal Balance After Bariatric Surgery in Patients With Morbid Obesity: A Prospective Observational Study

Summary

The goal of this prospective observational study is to understand how major weight loss after bariatric surgery may be associated with changes in the way the spine and pelvis are aligned in adults with morbid obesity.

The spine and pelvis work together to support the body and help maintain balance during standing and walking. In people with severe obesity, increased body weight and changes in body shape may affect posture, the position of the pelvis, the curves of the spine, and the way the upper body is balanced over the pelvis. Bariatric surgery can result in substantial weight loss, but it is not yet fully understood how these changes in body weight may affect the relationship between the spine and pelvis over time.

This study will follow patients undergoing bariatric surgery and will evaluate them before surgery and again at approximately 3, 6, and 12 months after surgery. The study is observational. This means that the researchers will observe, measure, and record changes occurring during the patients' clinical course rather than assigning participants to a specific treatment for the purpose of this study.

The main question of the study is whether spinopelvic alignment and overall body balance change during the first year after bariatric surgery as patients lose weight.

"Spinopelvic alignment" refers to the relationship between the spine and the pelvis. The pelvis forms the base on which the spine is positioned, and changes in pelvic position can be related to changes in the curves and orientation of the spine. "Sagittal balance" refers to how the head, trunk, spine, and pelvis are balanced from front to back when the body is viewed from the side.

Researchers will evaluate measurements describing the position and orientation of the pelvis, the curvature and alignment of the spine, and the relationship between the spine and pelvis. Measurements obtained before bariatric surgery will be compared with those obtained at approximately 3, 6, and 12 months after surgery.

By following the same patients at several different time points, the researchers will be able to determine whether any changes occur early after surgery, develop gradually as weight loss continues, or remain relatively stable throughout the first postoperative year.

The study will also examine the relationship between postoperative weight loss and changes in spinopelvic measurements. Patients may respond differently to major weight loss. Some people may develop measurable changes in posture or spinal and pelvic alignment, while others may show little or no change. The purpose of the study is therefore not to assume that weight loss will improve every spinal or pelvic measurement, but to objectively describe what happens to these measurements during the period of substantial weight reduction after bariatric surgery.

Understanding these changes may be important because body weight, posture, spinal curvature, pelvic position, and mechanical loading are closely related. Changes in how the body is balanced may potentially influence the mechanical demands placed on the spine, pelvis, and surrounding muscles and joints.

The results may improve understanding of the musculoskeletal effects of severe obesity and major weight loss. They may also provide information for future research on the relationship between obesity, weight reduction, posture, spinal alignment, pelvic position, spinal balance, and musculoskeletal health.

For patients and families, the study can be summarized simply as follows: the researchers want to find out whether losing a substantial amount of weight after bariatric surgery changes the way the spine and pelvis are positioned and balanced. Measurements taken before surgery will be compared with measurements taken during follow-up at 3, 6, and 12 months. By observing the same patients throughout the first year after surgery, the researchers hope to better understand how the spine and pelvis adapt as body weight decreases.

Conditions

• Obesity
• Spine Condition

Sponsors & Collaborators

• Marmara University

  lead OTHER

Principal Investigators

• Muhammed F Serttaş, Medical Specialist, Consultant · Department of Orthopaedic Surgery and Traumatology, Marmara University, Pendik Training and Research Hospital, İstanbul, Turkey

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2026-07-01

Primary Completion

2027-08-01

Completion

2027-08-01

Countries

• Turkey (Türkiye)

Study Locations