A Novel Classification of Sagittal Spinal Alignment to Aid Surgical Planning for Adult Spinal Deformity (CSSAASD)

Pelvic Incidence-Dependent Clustering of Sagittal Spinal Alignment: A Novel Classification to Aid Surgical Planning for Adult Spinal Deformity

Surgical outcomes, including radiographic outcomes, patient-reported outcomes, postoperative complications, and revision surgery rates, were compared in patients with adult spinal deformity who underwent correction surgery with reference to our pelvic incidence-dependent (PI-dependent) clustering of sagittal spinal alignment and existing standards (sagittal age-adjusted score [SAAS], global alignment and proportion [GAP] score, and Roussouly classification). Our findings may provide tangible guidance for surgical decision-making in ASD.

Study Overview

• Status: Not yet recruiting
• Conditions: Adult Spinal Deformity; Sagittal Deformity; Sagittal Imbalance; Sagittal Alignment
• Intervention / Treatment: Procedure: Correction strategy in reference to our PI-dependent clustering of sagittal alignment; Procedure: Correction strategy in reference to the SAAS score

• Study Type: Interventional
• Enrollment (Estimated): 200
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Shibao Lu, M.D.; Phone Number: 18810728213; Email: wdfdoctor@126.com
• Study Contact Backup: Name: Dongfan Wang, M.D.; Phone Number: 13821337116; Email: 1026607981@qq.com

Study Locations

• China
  • Beijing
    • Beijing, Beijing, China, 100053
      • Xuanwu Hospital Capital Medical University
      • Contact: Dongfan Wang; Phone Number: 13821337116; Email: wdfdoctor@126.com

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

1. ≥ 18 years of age at the time of treatment;
2. Complete radiographic data, including standing posteroanterior and lateral whole-spine radiographs, lumbar computed tomography, and lumbar magnetic resonance imaging;
3. Radiographic evidence of ASD: sagittal vertical axis ≥ 50 mm, pelvic tilt ≥ 25°, pelvic incidence-lumbar lordosis mismatch ≥ 10°, and/or thoracic kyphosis ≥ 60°.

Exclusion Criteria:

1. Any type of previous spinal surgery;
2. Other musculoskeletal problems impeding walking ability, syndromic or neuromuscular diseases such as Parkinson's disease, inflammatory conditions such as ankylosing spondylitis, infectious conditions such as spinal tuberculosis, metabolic diseases such as severe osteoporosis, and/or serious general medical conditions such as sepsis or malignancy;
3. Pathology of deformity as follows: post-traumatic deformity, adult idiopathic scoliosis of the thoracic spine, or de-novo lumbar scoliosis;
4. Hip joint Kellgren-Lawrence grade ≥ II, history of hip joint and/or knee joint pain, and/or previous joint replacement.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Patients with ASD undergoing correction surgery in reference to our novel criteria; Correcting deformity according to the PI-dependent clustering of sagittal spinal alignment.	Procedure: Correction strategy in reference to our PI-dependent clustering of sagittal alignment; For type I patients (PI < 39.56°), the target LL = -0.13*PI2+9.36*PI-134.08; for type II patients (39.56° ≤ PI < 49.16°), the target LL = 0.45*PI+26.57; for type III patients (49.16° ≤ PI < 58.31°), the target LL = -0.15*PI2+17.09*PI-420.57; for type IV patients (PI > 58.31°), the target LL = 0.06*PI2-7.55*PI+289.77. Prediction intervals of 95% confidence is adopted as the target LL range.
Other: Patients with ASD undergoing correction surgery in reference to SAAS score.; Correcting deformity according to the SAAS score.	Procedure: Correction strategy in reference to the SAAS score; This new score is composed of three sagittal parameters (PI-LL, PT and TPA). For these three parameters, points were assigned based on offset with age-adjusted targets 0 points if the parameter was within 10 years of the patient's age (Match). For each 20 years above the age-adjusted target, 1 point was added (e.g., + 1 point between + 10 and + 30, + 2 points between +30 and +50). Conversely, 1 point was subtracted for each 20 years below the age-adjusted target (e.g., -1 point between -10 and -30, -2 points between -30 and -50). SAAS was calculated by adding all 3 components, creating a discreet score that could have a negative value (under corrected) or positive value (over corrected). SAAS was sub-categorized into "SAAS-Under" if it was less than -1, "SAAS-Match" if it was between -1 and + 1 or "SAAS-Over" if it was greater than + 1.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Proximal Junctional Kyphosis	Proximal junctional kyphosis (PJK) was defined by a proximal junctional angle (PJA) (Cobb angle between the superior endplate of UIV+2 and inferior endplate of UIV) of > 10° and a PJA angle difference of > 10° from baseline at any time point up to latest follow-up.	Two years after surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Scoliosis Research Society-22	The 22-item SRS-22r questionnaire is specific to scoliosis-related patient-reported outcomes, and consists of 6 domains: function, pain, self-image, mental health, satisfaction, and subtotal, with each domain being scored from 1 to 5 where higher scores correspond to better patient outcomes.	One month, 3 months, 6 months, 1 year, and 2 years after surgery
Oswestry disability index	The validated ODI is a self-administered questionnaire for evaluating back-specific functional disability, consisting of 10 items with scores from 0 to 5, and higher ODI indicates more severe disability.	One month, 3 months, 6 months, 1 year, and 2 years after surgery
Achievement of minimal clinically important difference	A prespecified MCID of 10 points was used for the ODI. The minimum clinically important difference (MCID) values for the SRS-22r based on data from a Japanese cohort have previously been reported as follows: function = 0.90, pain = 0.85, self-image = 1.05, mental health = 0.70, and subtotal = 1.05.	Two years after surgery

Collaborators and Investigators

• Sponsor: Xuanwu Hospital, Beijing

Study record dates

Study Major Dates

• Study Start (Estimated): December 1, 2024
• Primary Completion (Estimated): December 1, 2027
• Study Completion (Estimated): December 1, 2027

Study Registration Dates

• First Submitted: June 17, 2024
• First Submitted That Met QC Criteria: June 17, 2024
• First Posted (Actual): June 24, 2024

Study Record Updates

• Last Update Posted (Actual): June 24, 2024
• Last Update Submitted That Met QC Criteria: June 17, 2024
• Last Verified: June 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Congenital Abnormalities
• Other Study ID Numbers: xuanwu_ASD

Plan for Individual participant data (IPD)

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

Drug and device information, study documents

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