An interventional study of Tether strategy and Reference in Proximal Junctional Kyphosis, sponsored by Hospices Civils de Lyon. Not yet recruiting at 6 sites in France. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-09-28.
Sponsored by Hospices Civils de Lyon · Not applicable, Interventional, and Treatment
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.
Exclusion Criteria:
Sub-laminar and/or interspinous tethers
Device: Tether strategy
Standard surgery
Procedure: Reference
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.
Patient will undergo the spine surgery as the standard of care, using only standard posterior rigid instrumentation (i.e. screws and metallic rods).
Sub-laminar and/or interspinous tethers efficacy to prevent PJK
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
Time frame: From enrollment to 24 months post-surgery
Sub-laminar and/or interspinous tethers efficacy to prevent PJF
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
Time frame: From enrollment to 24 months post-surgery
Sub-laminar and/or interspinous tethers efficacy to prevent surgery revision
Percentage of patients with an indication of revision surgery
Time frame: From enrollment to 24 months post-surgery
Sub-laminar and/or interspinous tethers efficacy to prevent the level of disabilty
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.
Time frame: From enrollment to 24 months post-surgery
Sub-laminar and/or interspinous tethers efficacy to prevent pain
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.
Time frame: From enrollment to 24 months post-surgery
Sub-laminar and/or interspinous tethers efficacy to enhance quality of life
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.
Time frame: From enrollment to 24 months post-surgery
Sub-laminar and/or interspinous tethers efficacy to prevent post-operative complications
The number of peri- and post-operative complications including mechanical complication due to the device, infections, neurological and general complications.
Time frame: From enrollment to 24 months post-surgery
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
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.
Time frame: From enrollment to 24 months post-surgery
This study is not yet recruiting, as verified in Sep 2026. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Hospices Civils de Lyon