Inducible Displacements of the Sacroiliac Joint Measured With CTMA

Not Applicable

Not yet recruiting

Brief Summary: To evaluate the influence of different surgical treatment options for kyphoscoliosis we measure the movement of the SI joint with Radiostereometric analysis (RSA) after lumbar fixation with CT motion analysis (CTMA).

Detailed Description: CTMA is a high precision in vivo measuring method for motion. We intend to measure sacroiliac joint (SIJ) movement in long fixations compared to short fixations. The Center for Implant and Radiostereometric Research Oslo (CIRRO) has extensive experience with RSA and established state of the art measuring method of movement in the SIJ. We have compared the methode with CTMA and established a methode for CTMA measurements at CIRRO. We will measure the movement in the SIJ in patients that have long fixations of 3 or more segments down to S1 and compare it to one segment fixation in the level of L4/5. Null hypothesis

* The SI movement will not increase because of long fixation down to sacrum, the SIJ will not work as an adjacent level and not compensatory increase the movement.

* The increased movement will not result in low back pain and /or pseudo radicular pain to the lower limbs CTMA is a high accuracy measuring method comparable to RSA. With a precision of RSA of 1 degree for rotation we need 10 patients in each group to detect a difference of 2 degrees for power of 90% on an alpha = 99% confidence level. Taking drop-outs into account we need a group size of 15 resulting in 30 patients (Two- sided T-test).

Recruitment & Eligibility

Inclusion Criteria

Long fixations of 3 or more segments down to S1, (also including not correction surgery patients).
One segment fixations in the level of L4/5 regardless of olisthesis.

Exclusion Criteria

Medical conditions that affect the SI joint (Sacroileitis, Ankylosing spondylitis, psoriasis, autoimmune illness)
Do not want to participate and not able to answer PROMs

Arm && Interventions

Group	Intervention	Description
Long fixation	CTMA	CT in a neutral and then by provocation (anterior straight leg raise and figure-of-four).
One segment fixation	CTMA	CT in a neutral and then by provocation (anterior straight leg raise and figure-of-four).

Primary Outcome Measures

Name	Time	Method
Movement	12 months	Compare the induced movement of the SIJ joint Movement measured in millimeter around x, y, z axis 3 dimensional and usually in the range of -2-2 millimeters when comparing neutral position to provoked position.

Secondary Outcome Measures

Name	Time	Method
EQ 5D 5L	12 months	From the Norwegian quality register for spinal surgery. EQ-5D health states; When a person completes the EQ-5D questionnaire, the descriptive system produces a 5-digit health status profile that represents that person's level of reported problems on the five EQ-5D health dimensions. A numerical value can be attached to each EQ-5D health state to reflect how good or bad a health state is according to the preferences of the general population of a country/region. The five levels in each dimension are worded as (1) 'not /no problems', (2) 'slight problems', (3) 'moderate problems', (4) 'severe problems', and (5) 'unable to' (mobility, self-care, usual activities), 'extreme' (pain/depression), or 'extremely' (anxiety/depression).
Satisfaction og treatment and result on a 7 point likert scale	12 months	From the Norwegian quality register for spinal surgery. 1. Complete recovered 2. A lot better 3. A bit better 4. No change 5. A bit worse 6. A lot worse 7. Worse than ever
Oswestry disability index	12 months	From the Norwegian quality register for spinal surgery. 0-20% minimal disability, 21-40% moderate disability, 41-60% sever disability, 61-80% crippled, 81-100% bed bound
NRS Numeric rating scale back pain and pain to the lower limbs	12 months	From the Norwegian quality register for spinal surgery. 0-10 pain scale for backpain and pain in the lower limbs. 0 represent no pain and 10 the worst pain ever.