Delayed Neurologic Complications of Vertebral Bone Cement Injections
Bibliographic record
Abstract
Minimally invasive techniques have changed many surgical paradigms.In some instances, they have enabled surgeons to perform procedures that would otherwise be impossible.Elsewhere, they have minimized potential morbidity.In the field of neurological surgery, deep brain stimulation would fit in the former category and endovascular treatment of cerebral aneurysms the latter.Reinforcement of pathological fractures of the vertebral axis, usually with polymethyl methacrylate (PMMA) injection, provides instant fixation of unstable and painful fractures and is usually well tolerated by patients.This technique, performed either as vertebroplasty or kyphoplasty, affords both of the aforementioned advantages and has therefore been a welcome addition to the surgical armamentarium.Significant improvement in pain is reported in about 90% of patients after PMMA vertebral body embolization for osteoporotic compression fractures 1 .Benefit appears to be durable, as evidenced by a study with a mean follow-up of 48 months 2 .The potential for complications, however, is not negligible.These include pulmonary venous embolism and spinal cord or nerve root compression from aberrant PMMA.The literature suggests that these complications are rare 1 .Symptomatic pulmonary embolism typically manifests itself rapidly and, similarily, one would expect significant PMMA in the spinal canal to cause symptoms right after the injection.Neurological problems associated with PMMA vertebral injections may, however, manifest themselves at a later date 3 .It is important that practitioners of this technique recognize when a patient is having an adverse event.We report here two patients with delayed symptomatic lesions that were, eventually, treated surgically and improved clinically. CASE REPORTS Case 1An 83-year-old woman with osteoporosis presented to a surgeon with mid-thoracic pain and kyphosis.She underwent kyphoplasty at T8.The initial films were felt by the treating physician to be satisfactory, and there was some improvement in pain control.However the patient had another fall, about a week after the kyphoplasty and immediately thereafter began complaining of back pain.Plain radiographs and an MRI done at the time looked satisfactory (Figure 1A and B), but one week later she began to develop numbness and weakness of her lower extremities, soon loosing her ability to walk.A follow-up MRI demonstrated that there had been further collapse at both T8 and T9, with retropulsion of some bone into the spinal canal at T8 (Figure 1C).The patient underwent a posterior decompression
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.004 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.005 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".