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NCT Number: NCT07618897

Efficacy of Sub-laminar and/or Interspinous Tethers to Prevent Proximal Junctional Kyphosis After Surgical Correction of Adult Spinal Deformity

PJK (proximal junctional kyphosis) at the upper end of spinal fusions after surgical correction of adult spinal deformity is not uncommon. Two-thirds of cases are observed within the first 3 months after surgery and 80% within the first 18 months. PJK is consequently a common problem after surgery for adult spinal deformity, representing one of the most frequent complications following this kind of procedure. Although the first-line treatment of this event is conservative, surgery may be necessary in around 30-40% of cases. Revision surgery generally consists of extending the posterior spinal instrumentation.

Prophylactic vertebroplasty has been proposed to reduce the risk of PJK and PJF, with promising results but with the limitation of reinforcing only the bony structures, with no action on the soft tissues. In this context, some authors have reported that the use of tethers, creating a transitional zone at the upper end of the construct between the fused and the non-instrumented spine, could reduce the occurrence of this complication (PJK). One of the hypotheses is that the use of a topping-off system results in a transitional zone reducing stresses at the junctional spine and may reduce the occurrence of both PJK and the need for reoperation.

Compared with other topping-off systems, such as hooks, the surface of contact provided by the bands on the posterior arches is much greater and the primary stability much better. In addition, the risk of malposition is extremely low.

The aim of this study is therefore to compare the occurrence of PJK and PJF in patients for whom tethers were implanted at the upper end of the instrumentation versus patients for whom no tether system was used.

In a retrospective study conducted in the neurosurgery department of the HCL on 38 patients undergoing multilevel spine instrumentation with junctional tethers, PJK occurred in 8 of them (21%) after 24 months of follow-up.

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Key information

Conditions

Proximal Junctional Kyphosis

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Patient men and women older than 18
  • Patient indicated spinal posterior fusion and instrumentation with the upper end (UIV with screws) between T9 and L2 and the lower end between L5 and iliac
  • Constructs ≥4 levels (i.e., ≥4 discs included)
  • Patient able to signed a consent form
  • Patient able to fill a self-administered questionnaire
  • Patient affiliated to health care insurance (social security in France

Exclusion criteria

  • Allergy to metal
  • Cimentoplasty at the junctional zone (UIV, UIV+1 and/or UIV+2)
  • Bone metabolism disorders that potentially compromise the mechanical support expected from this type of implant.
  • Morbid obesity (BMI > 40)
  • Patients with infection (in particularly osteomyelitis)
  • Cancer of lesss than 5 years or currently treated
  • Acute trauma
  • Immunodepression
  • Parkinson
  • Chronic inflammatory disease
  • Severe psychological disorders
  • Pregnancy or women breastfeeding
  • Inadequate tissue coverage of implant site,
  • Interference with other critical anatomical structures.
  • Patient not being able to understand the objectives of the study or refusing to comply with postoperative instructions
  • Patient participating in an ongoing study that may interfere with this study
  • Patient under legal protection

Treatment and study plan

Tether strategy

Device

During spine surgery sub-laminar or interspinous bands are utilized in combination with standard posterior rigid instrumentation (i.e. screws and metallic rods). They are typically implanted at the upper vertebral level, above the cranial screws, and then connected to the rods. Their implantation is based on standard surgical techniques for spine surgeons.

Reference

Procedure

Patient will undergo the spine surgery as the standard of care, using only standard posterior rigid instrumentation (i.e. screws and metallic rods).

Primary outcomes

  1. Sub-laminar and/or interspinous tethers efficacy to prevent PJK

    Time frame: From enrollment to 24 months post-surgery

    Percentage of patients with PJK during the first post-operative 24 months with PJK defined as :

    • a proximal junctional sagittal Cobb angle (PJA) between the lower endplate of uppermost instrumented vertebra (UIV) with screws and the upper endplate of 2 supra-adjacent vertebra ≥15
    • a 15° delta between 24months post operative PJA and preoperative PJA These 2 parameters will be assessed by an independent committee using radiographic images preop and 24 months postop

Secondary outcomes

  1. Sub-laminar and/or interspinous tethers efficacy to prevent PJF

    Time frame: From enrollment to 24 months post-surgery

    Comparison between the 2 randomized groups with or without tethers at 24 months: Percentage of patients with PJF, defined as a progressive process in the spectrum of PJK with structural failures such as vertebral body fracture and/or posterior ligament complex, and vertebral subluxation

  2. Sub-laminar and/or interspinous tethers efficacy to prevent surgery revision

    Time frame: From enrollment to 24 months post-surgery

    Percentage of patients with an indication of revision surgery

  3. Sub-laminar and/or interspinous tethers efficacy to prevent the level of disabilty

    Time frame: From enrollment to 24 months post-surgery

    Disability assed with Oswestry Disability Index questionnaire. It is composed of questions on the following items : pain intensity, personal care (washing, dressing), lifting objects, moving around, sitting or standing, sleeping, sex life, social life, and travel/transportation. Each items is scored from 0 to 5, 0 being absence of disability and 5 the most severe disability. The final score range from 0 to 50 and there is 6 level of disability according to final score categories: 0-4 no disability, 5-14 light disability, 15-24 moderate disability, 25-34 severe disability and 35-50 complete disability.

  4. Sub-laminar and/or interspinous tethers efficacy to prevent pain

    Time frame: From enrollment to 24 months post-surgery

    Evolution of radicular and lumbar Pain assessed with a Visual Analogic Scale rated from 0 to 10, 0 being the absence of pain and 10 the worst pain ever experienced.

  5. Sub-laminar and/or interspinous tethers efficacy to enhance quality of life

    Time frame: From enrollment to 24 months post-surgery

    Evolution of the mean Quality-of-Life score will be assessed using the EQ-5D-5L questionnaire. The EQ-5D-5L, developed by the EuroQol Group to improve sensitivity and reduce ceiling effects, includes two components: the descriptive system and the visual analogue scale (EQ VAS). The descriptive system covers five dimensions (mobility, self-care, usual activities, pain/discomfort, anxiety/depression), each rated on five levels from no problems to extreme problems, generating a 5-digit health state code. The EQ VAS records the patient's self-rated health on a vertical scale ranging from the best to the worst imaginable health, providing a quantitative measure based on the patient's own judgement.

  6. Sub-laminar and/or interspinous tethers efficacy to prevent post-operative complications

    Time frame: From enrollment to 24 months post-surgery

    The number of peri- and post-operative complications including mechanical complication due to the device, infections, neurological and general complications.

  7. Assess the efficiency of implanting tethers at the upper part of the construct in patient with an indication for spinal posterior fusion performing cost-utility and cost-effectiveness analyses

    Time frame: From enrollment to 24 months post-surgery

    Incremental cost-utility and cost-effectiveness ratios of implanting tethers at the upper part of the construct (tethers group) compare to the standard procedure without tethers at 24 months post-surgery.

Study contacts

Contact information is provided by the study sponsor or research team.

Cédric BARREY, Ph

CONTACT

[email protected]

+33 4 72 11 80 67

Julien BERTHILLER

CONTACT

[email protected]

+33 4 27 85 63 01

Sponsors and collaborators

Lead sponsor

Hospices Civils de Lyon

Other

Registry information

Official study title

Efficacy of Sub-laminar and/or Interspinous Tethers to Prevent Proximal Junctional Kyphosis After Surgical Correction of Adult Spinal Deformity - Randomized Multicentric Single Blind Controlled Trial

Acronym: TRANSITION

Important dates

Study start
2026
Primary completion
2030
Study completion
2030
First posted
Jun 1, 2026
Registry last updated
Jun 1, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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