Michael Payer

Idiopathic spinal cord herniation (ISCH) is a rare spinal disease, in which chronic cerebrospinal fluid pulsations push the arachnoid and adjacent thoracic spinal cord region through an antero-lateral dural defect of congenital, post-traumatic, or inflammatory/erosive origin. Symptomatic patients commonly present around the 5th decade of life with slowly progressive myelopathy. Diagnosis relies on high-resolution magnetic resonance imaging. Stable mild cases may be observed, whereas in progressive symptomatic situations, surgical spinal cord reposition and dural defect repair with a dural patch is the preferred treatment. We present a case of ISCH at T5/6 and a review the literature.

Background Different treatment options exist for symptomatic single-level degenerative anterolisthesis and stenosis. While simple micro-decompression has been advocated lately, most authors recommend posterior decompression with fusion. In recent years, decompression and dynamic transpedicular stabilisation has been introduced for this indication. The aim of this study was to evaluate the safety and efficacy of decompression and dynamic transpedicular stabilisation with the Dynesys® system in single-level degenerative anterolisthesis and stenosis. Methods Thirty consecutive patients with symptomatic single-level degenerative anterolisthesis and stenosis without scoliosis underwent decompression and single-level Dynesys stabilisation at the level of degenerative anterolisthesis. Patients were followed prospectively for 24 months with radiographs, Oswestry Disability Index scores, visual analogue scale (VAS) for back and leg pain, and estimated pain-free walking distance. Results At the 2-year follow-up, back pain was reduced from 6.5 preoperatively to 2.5, leg pain from 5.4 to 0.6. The pain-free walking distance was estimated at 500 m preoperatively and at over 2 km after 2 years, while the ODI decreased from 54 % to 18 %. Screw loosening was found in 2/30 cases. Symptomatic adjacent segment disease was found in 3/30 patients between 12 and 24 months postoperatively. Conclusions Single-level Dynesys stabilisation combined with single- or multi-level decompression seems to be a safe and efficient treatment option in single-level degenerative anterolisthesis and stenosis over an observation period of 2 years, avoiding iliac crest or local bone grafting required by fusion procedures. However, it does not seem to avoid adjacent segment disease.

Minimal-access technology has evolved rapidly with "tubular" or "percutaneous" approaches for decompression and stabilization in the lumbar spine. Potential benefits (smaller scars, diminished local pain, reduced blood loss, reduced postoperative wound pain, shorter hospital stays) have to be weighed against possible drawbacks (reduced orientation, steep learning curve, increased radiation exposure, dependency on technology, cost). While non-comparative case series are often rather enthusiastic, comparative studies and particularly RCTs are scarce and might convey a more realistic appreciation. A MEDLINE search via PubMed was performed to find all English-language studies comparing "open" or "traditional" or "conventional" with "minimally invasive" or "percutaneous" or "tubular" approaches in degenerative lumbar spine surgery. Only nine comparative studies could be retrieved altogether. No clear benefit could be found for minimally invasive procedures in lumbar disc herniation, TLIF, or PLIF. There seems to be a slight advantage in terms of hardware safety in open procedures. This review, based solely on the very limited number of available comparative studies, shows no relevant benefit from minimally invasive techniques, and a tendency for more safety in open procedures in lumbar disc herniation, TLIF and PLIF.

Spontaneous idiopathic acute spinal subdural hematomas are highly exceptional. Neurological symptoms are usually severe, and rapid diagnosis with MRI is mandatory. Surgical evacuation has frequently been used therapeutically; however, spontaneous recovery in mild cases has also been reported. We present a case of spontaneous recovery from severe paraparesis after spontaneous acute SSDH, and review the English-speaking literature.

Superficial siderosis of the central nervous system is a rare disorder with hemosiderin deposition in the spinal and cranial leptomeninges and subpial layer, mostly from repetitive subarachnoid hemorrhage. Progressive sensorineural deafness, cerebellar ataxia, and pyramidal signs comprise the typical clinical presentation. We describe a 47-year-old patient, who showed initial 2-year improvement after successful occlusion of an intradural bleeding source at T4. Secondary progression of symptoms without further bleedings was noted thereafter, with a clinical picture of amyotrophic lateral sclerosis. This case illustrates that the disease may progress secondarily even without re-bleedings, and that secondary progression might be due to a similar pathomechanism as in amyotrophic lateral sclerosis.

C1-C2 instability or painful osteoarthritis are recognised indications for posterior atlanto-axial fixation. In the traditional trans-articular C1-C2 screw fixation, up to 20% of patients cannot have safe placement of bilateral screws in the event of a medially located vertebral artery and a straight screw trajectory in the sagittal plane. The more recently developed C1-C2 fixation technique with individual C1 lateral mass screws and converging C2 pars screws can be employed in case of a medially located vertebral artery and has comparable biomechanical strength. This is a prospective observational study to investigate the advantages, the safety, and the drawbacks of posterior atlanto-axial fixation with polyaxial C1 lateral mass screws and C2 pars screws. Twelve consecutive patients with C1-2 instability (n = 11) and painful osteoarthritis (n = 1) underwent a posterior atlanto-axial fixation with polyaxial C1 lateral mass screws and C2 pars screws. The average follow-up was 16 months and all patients reached the 12-month follow-up. No hardware failure occurred in any of the patients. Correct screw placement and construct stability was found in all 12 patients (100%) at 6 and 12 months after surgery. Mean neck pain on a visual analogue scale (VAS) was 2.1 at 6 months and 2.0 at 12 months. Only transient complications were observed: one patient presented with progressive intestinal herniation through the iliac crest scar; one suffered from severe pain at the posterior iliac crest for 3 months and three patients complained of annoying pain/dysaesthesia in the C2 dermatome for 3–6 months after surgery. This study confirms that posterior atlanto-axial fixation with polyaxial C1 lateral mass screws and C2 pars screws is a safe and effective surgical option in the treatment of atlanto-axial instability or painful osteoarthritis.