Why Revision Surgery Happens
The decision to perform revision spinal deformity surgery — to reoperate on a spine that has already been instrumented — is one of the most consequential decisions in our subspecialty. Every revision case carries higher technical complexity, higher complication rates, and longer recovery than the original procedure.
Understanding why revision becomes necessary is the first step in deciding whether it is appropriate and what it can realistically achieve. In our practice, we see revision cases falling into several distinct categories:
1. Pseudarthrosis (Failed Fusion)
Pseudarthrosis occurs when the bony fusion mass fails to consolidate across one or more levels, leaving a mobile non-union that acts as a stress riser on the adjacent instrumentation. The presentation is typically back pain that increases with activity, often years after the original surgery. Imaging shows a lucent line at the fusion level, and CT is definitive.
Implant breakage — particularly rod fractures — is a common associated finding and a reliable clinical indicator of underlying pseudarthrosis. Not all pseudarthroses require intervention. A pseudarthrosis at a low-stress level in an asymptomatic patient can often be observed. When pain is significant or progressive implant failure is occurring, revision with extension of fusion, hardware replacement, and augmentation of the bone graft is the standard approach.
2. Progressive Deformity (Distal Adding-On or Proximal Junctional Kyphosis)
In adolescent idiopathic scoliosis, the most common late deformity is "adding-on" — progressive curve development at the distal end of the fusion, where the lowest fused vertebra was not selected to fully neutralise the unfused lumbar curve. This results in a gradually worsening trunk shift and ultimately may require extension of the fusion to a lower level.
Proximal junctional kyphosis (PJK) is a kyphotic angulation that develops at the junction above the fusion construct — a recognised complication of adult deformity surgery and increasingly described in adolescents with long fusions. Severe PJK with neurological compromise is a surgical emergency; milder forms are often managed conservatively.
3. Implant Failure (Rod Fracture, Screw Pullout)
Modern titanium alloy rods are designed for permanent implantation, but they are not indestructible. Rod fracture through a pseudarthrosis zone, screw pullout in osteoporotic bone, and rod dislodgement are all encountered in long-term follow-up. The clinical presentation varies from asymptomatic incidental finding to acute onset back pain with or without deformity progression. Management depends on whether the underlying fusion is solid. If it is, simply removing the broken hardware may suffice. If not, revision fusion and hardware replacement is required.
4. Infection (Late Deep Infection)
Late deep wound infection — presenting months or years after primary surgery — is a well-recognised complication of spinal instrumentation, with a reported incidence of 1–4% in adult deformity surgery. The organism is most commonly low-virulence (Propionibacterium acnes, coagulase-negative Staphylococcus), and the presentation is often indolent: gradual wound breakdown, persistent drainage, or back pain that does not follow the expected post-operative trajectory.
Management typically requires surgical debridement, lavage, and a prolonged course of targeted antibiotics. Whether the hardware can be retained or must be removed depends on whether the fusion is solid at the time of presentation.
5. Flat Back Deformity
Flat back occurs when lumbar lordosis is lost following spinal fusion — most commonly in older fusion techniques that used Harrington distraction rods, which straightened the natural lumbar curve as a side effect of curve correction. The result is a forward-leaning posture that cannot be voluntarily corrected, producing progressive back fatigue, pain, and difficulty looking horizontally.
Osteotomy — typically a pedicle subtraction osteotomy (PSO) or Smith-Petersen osteotomy — to restore lordosis is a highly effective revision procedure, but it carries the highest neurological risk of any elective spinal operation and requires a surgeon with specific experience in these techniques.
Revision surgery is not a failure of the original procedure — it is proof that spinal deformity care is a long-term relationship, not a single event. We enter every revision with that understanding.
How We Evaluate Revision Cases
Our revision protocol begins with a detailed review of all prior operative records, implant records (manufacturer, lot number, implant size), and serial imaging since the original surgery. We request standing full-length scoliosis films, flexion-extension lateral views to assess the stability of the construct, CT to evaluate fusion status, and MRI where neural compression is suspected.
We then categorise the revision need:
- Is the existing fusion solid, partial, or absent?
- Is the hardware intact, at risk, or already failed?
- Is the deformity static, slowly progressive, or rapidly progressing?
- Are there neurological symptoms?
- What are the patient's functional limitations and pain level?
This categorisation drives the urgency and the nature of the revision. Not every abnormality on imaging requires surgery — revision surgery is only offered when the expected benefit to the patient's function and quality of life outweighs the real risks of a technically demanding reoperation.
Honest Conversations About Risk
Revision spinal surgery carries higher complication rates than primary surgery across every published series. Blood loss is typically greater, operative time is longer, the dural sac is at higher risk from scar tissue adhesions, and the infection risk is elevated due to prior wound disruption. We do not minimise these risks in our consent process — patients and families need to understand them accurately to make a genuinely informed decision.
What we can offer is the experience, the intraoperative monitoring infrastructure, and the multidisciplinary support to manage these complications when they arise. Our revision cases are planned in a dedicated session with two surgeons, and all complex revisions are discussed pre-operatively at our MDT.
Accepting Referrals for Revision
We accept referrals for revision scoliosis surgery from patients who have been operated elsewhere — in Turkey and internationally. We do not require the original surgery to have been performed at our centre. Families seeking a second opinion before agreeing to a revision recommendation from their current surgeon are also welcome to contact us for an independent assessment. We aim to provide a written opinion on all referred cases within 5 working days of receiving the full imaging package.