Empty polyetheretherketone (PEEK) cages in anterior cervical diskectomy and fusion (ACDF) show slow radiographic fusion that reduces clinical improvement: results from the prospective multicenter "PIERCE-PEEK" study.

BACKGROUND: Anterior cervical diskectomy and fusion (ACDF) is a well-established surgical treatment for radiculopathy and myelopathy. Previous studies showed that empty PEEK cages have lower radiographic fusion rates, but the clinical relevance remains unclear. This paper's aim is to provide high-quality evidence on the outcomes of ACDF with empty PEEK cages and on the relevance of radiographic fusion for clinical outcomes. METHODS: This large prospective multicenter clinical trial performed single-level ACDF with empty PEEK cages on patients with cervical radiculopathy or myelopathy. The main clinical outcomes were VAS (0-10) for pain and NDI (0-100) for functioning. Radiographic fusion was evaluated by two investigators for three different aspects. RESULTS: The median (range) improvement of the VAS pain score was: 3 (1-6) at 6 months, 3 (2-8) at 12 months, and 4 (2-8) at 18 months. The median (range) improvement of the NDI score was: 12 (2-34) at 6 months, 18 (4-46) at 12 months, and 22 (2-44) at 18 months. Complete radiographic fusion was reached by 126 patients (43%) at 6 months, 214 patients (73%) at 12 months, and 241 patients (83%) at 18 months. Radiographic fusion was a highly significant (p < 0.001) predictor of the improvement of VAS and NDI scores. CONCLUSION: This study provides strong evidence that ACDF is effective treatment, but the overall rate of radiographic fusion with empty PEEK cages is slow and insufficient. Lack of complete radiographic fusion leads to less improvement of pain and disability. We recommend against using empty uncoated pure PEEK cages in ACDF. TRIAL REGISTRATION: ISRCTN42774128. Retrospectively registered 14 April 2009.

Do we know the outcome predictors for cauda equine syndrome (CES)? A retrospective, single-center analysis of 60 patients with CES with a suggestion for a new score to measure severity of symptoms.

OBJECTIVE: Despite the awareness and familiarity of almost every medical professional with the cauda equine compression syndrome (CES), risk factors for a poor prognosis of the disease remain elusive. Even the relationship between subsequent outcome and the time elapsed from the time of appearance of symptoms to surgery taking place remain obscure. The aim of our study, therefore, was to analyze a relatively large population of our own patients studied consecutively, to identify outcome predictors for CES and to propose a clinical score for CES symptoms (Berlin CES score). METHODS: We screened the hospital's electronic database retrospectively for patients admitted with CES between 2001 and 2010. Since our hospital is a superregional trauma center with standardized emergency room procedures, all patients included in the study underwent the same routine. Using baseline data, we analyzed the following parameters: duration of symptoms, period of time between diagnosis and imaging, respectively, surgery; pre- and postoperative pain, motor deficits, reflex changes, urinary and bowl dysfunctions, reduced anal wink, saddle anesthesia, genital or perianal sensations and residual urine. The semi-quantitative assessment of the neurological outcome was performed by application of the Berlin CES score. RESULTS: Surprisingly, we were not able to identify any single parameters that could reliably predict the outcome of the disease. We were able to show statistically significant correlations between a high preoperatively Berlin CES score (i.e., a weighted summation of bladder dysfunction, rectal dysfunction, genital sensation, perianal sensation, rectal tone and saddle anesthesia) and a poor outcome regarding the postoperative existence of perianal (p < 0.001) and genital (p = 0.001) hypoesthesia, as well as reduced rectal tone (p = 0.0047). There was no significant interference of bladder or bowel function. Further analysis, in which we considered the time between diagnosis and surgery, revealed that both patients operated within 24 h and after 48 h could benefit from the intervention. Consequently, we were not able to show a correlation between speed of surgical treatment and outcome. CONCLUSION: Although we analyzed a relatively large cohort, we were not able to identify single parameters that were capable of reliably predicting the outcome of patients with CES. Nonetheless, we were able to show that consideration of multiple parameters of symptomatology would enable an improvement in making a prognosis. In conclusion, we propose establishing a simple semi-quantitative clinical score of the main symptoms of CES.

Efficacy and safety of a collagen matrix for cranial and spinal dural reconstruction using different fixation techniques.

OBJECT: The use of dural grafts is frequently unavoidable when tension-free dural closure cannot be achieved following neurosurgical procedures or trauma. Biodegradable collagen matrices serve as a scaffold for the regrowth of natural tissue and require no suturing. The aim of this study was to investigate the efficacy and safety of dural repair with a collagen matrix using different fixation techniques. METHODS: A total of 221 patients (98 male and 123 female; mean age 55.6 +/- 17.8 years) undergoing cranial (86.4%) or spinal (13.6%) procedures with the use of a collagen matrix dural graft were included in this retrospective study. The indications for use, fixation techniques, and associated complications were recorded. RESULTS: There were no complications of the dural graft in spinal use. Five (2.6%) of 191 patients undergoing cranial procedures developed infections, 3 of which (1.6%) were deep infections requiring surgical revision. There was no statistically significant relationship between the operative field status before surgery and the occurrence of a postoperative wound infection (p = 0.684). In the 191 patients undergoing a cranial procedure, cerebrospinal fluid (CSF) collection occurred in 5 patients (2.6%) and a CSF fistula in 5 (2.6%), 3 of whom (1.6%) required surgical revision. No patient who underwent an operation with preexisting CSF leakage had postoperative CSF leakage. Postoperative infection significantly increased the risk for postoperative CSF leakage. The collagen matrix was used without additional fixation in 124 patients (56.1%), with single fixation in 55 (24.9%), and with multiple fixations in 42 (19%). There were no systemic allergic reactions or local skin changes. Follow-up imaging in 112 patients (50.7%) revealed no evidence of any adverse reaction to the collagen graft. CONCLUSIONS: The collagen matrix is an effective and safe cranial and spinal dural substitute that can be used even in cases of an existing local infection. Postoperative deep infection increases the risk for CSF leakage.

Use of gelatin-thrombin matrix hemostatic sealant in cranial neurosurgery.

The present study evaluated the hemostatic efficacy and handling of gelatin-thrombin matrix hemostatic sealant during intracranial procedures. A retrospective analysis of 478 consecutive patients undergoing intracranial procedures identified seven patients with acute intense or persistent intraoperative bleeding which could not be arrested in time by standard hemostatic methods. The efficacy of gelatin-thrombin matrix was assessed by determining bleeding severity before and after application, time to hemostasis, amount of gelatin-thrombin matrix necessary, need for additional hemostatic measures, and need for reoperation to control hemorrhage. Immediate hemostasis was achieved in five of seven patients. Two of these five patients had abnormal clotting parameters. Cessation of bleeding was achieved by additionally applying either fibrinogen or gelatin sponge to the bleeding site in the other two patients. No complications attributable to gelatin-thrombin matrix use were recorded. The gelatin-thrombin matrix was ready to use within 1 minute in every case. Gelatin-thrombin matrix appears to be an effective, easy-to-use, and readily available hemostatic agent for cranial neurosurgery. Combination with fibrinogen is recommended in special situations.

Rapidly progressive paraplegia due to an extradural lumbar meningocele mimicking a cyst. Case report.

Unlike arachnoid meningoceles, arachnoid cysts frequently cause local pressure effects probably because there is no free communication between the cyst and the subarachnoid space. Following the first detailed description of cystic lesions of spinal nerve roots by Tarlov in 1938, a simplified classification of spinal meningeal cysts was developed in 1988, containing three major categories. The authors report on a lumbar intraspinal extradural meningocele that caused incomplete paraplegia in an otherwise healthy 31-year-old man in whom magnetic resonance imaging revealed stigmata of Scheuermann disease. Intraoperatively, the lesion was classified as a transitional-type lesion, in accordance with Type IA of the Nabors classification, because a communication with the subarachnoid space was observed. After complete removal of the meningocele, the patient's recovery was prompt and complete.