Prediction parameters of bone flap resorption following cranioplasty with autologous bone.

OBJECTIVE: The number of patients who need cranioplasty after decompressive craniectomy has increased. In most cases, autologous bone flaps are used for cranioplasty, and there have been reports of the complication of bone flap resorption. Based on these facts, we analysed patients who underwent cranioplasty in our institution to learn about potential risk factors of cranioplasty. METHODS AND RESULTS: We performed a retrospective study and analysed 58 patients who underwent cranioplasty between 2006 and 2013. We found that patients with a defect size >120cm(2) whose reimplantation was delayed tended to have a risk of bone flap resorption. CONCLUSION: Patients with delayed reimplantation and a defect size >120cm(2) show a tendency of aseptic bone flap resorption. In these cases, a patient-specific implant (PSI) could be the first choice material for this procedure to reduce the rate of this complication.

Tremor associated with Klinefelter syndrome--a case series and review of the literature.

BACKGROUND: Previous case series suggested a link between Klinefelter syndrome (KS) and essential tremor (ET) or an ET-like syndrome. METHODS: We investigated three KS-patients with tremor including tremor-analyzes and discuss our data in context to findings from a literature review. The clinical outcome after deep brain stimulation (DBS) is also reviewed. RESULTS: Tremor in KS is predominantly a postural and kinetic tremor that resembles ET. Our patients were further characterized by absent family history for tremor in first degree relatives, lack of subjective alcohol responsiveness inquired by history, and tremor onset in childhood. One of our patients and two cases from literature improved after DBS of the ventral intermediate nucleus (VIM) of the thalamus. CONCLUSIONS: Tremor in KS shares several features with ET. If other characteristics such as family history, alcohol responsiveness, and age at tremor onset may serve as discriminating factors from ET, needs to be further investigated. First observations suggest that VIM-DBS may be efficacious.

Protecting facet joints post-lumbar discectomy: Barricaid annular closure device reduces risk of facet degeneration.

Lumbar discectomy is an effective treatment for lumbar disc herniation (LDH). Although the majority of patients experience successful outcomes, a significant fraction will experience a recurrence of their back pain due to facet joint degeneration. Facet joint degeneration after discectomy may be the result of excessive nuclear removal, disc space narrowing, and annular injury. This study investigated whether implantation with the Barricaid annular closure device (ACD) during discectomy reduced the rate of facet degeneration. Inclusion criteria were primary lumbar disc herniation failing conservative treatment, Visual Analog Scale (VAS) Leg≥40/100, Oswestry Disability Index (ODI)≥40/100 and defects that were ≤60 mm2 (Barricaid arm only), and patient age 18-75. CT interpretations were collected preoperatively and 12 months post-discectomy. Patients implanted with Barricaid had significantly reduced rates and grades of facet degeneration than patients without Barricaid. Reinforcing the annulus fibrosus with Barricaid during lumbar discectomy may slow the progression of facet joint degeneration.

A prospective cohort study of close interval computed tomography and magnetic resonance imaging after primary lumbar discectomy: factors associated with recurrent disc herniation and disc height loss.

STUDY DESIGN: Prospective cohort study. OBJECTIVE: We performed a prospective cohort study with standardized postoperative lumbar imaging every 3 months for a year then annually to assess the incidence and factors associated with same-level recurrent disc herniation. SUMMARY OF BACKGROUND DATA: The true incidence of same-level recurrent disc herniation after lumbar discectomy is unclear. Retrospective studies have reported widely varying incidences between 3% and 18%. Prospective controlled studies are lacking. METHODS: A total of 108 patients undergoing first-time lumbar discectomy for refractory radiculopathy were enrolled. Baseline lumbar CT and MRI and standardized clinical data were assessed before surgery, and CT and MRI scans repeated 6 weeks, 3, 6, 9, 12, and 24-months after surgery and at the time of recurrent sciatica. Age, weight, preoperative disc volume, and height, volume of disc removed, and size of anular defect were compared with postoperative disc height loss and recurrent disc herniation using regression analysis. RESULTS: One hundred patients (41 +/- 10 years old) were available for 1-year (93%) and 76 (70%) for 2-year follow-up (mean follow-up: 25 +/- 12 months). Improvement in all outcome measures was observed by 6 weeks after surgery (P < 0.005). An 18% loss of disc height was observed 3 months after surgery, progressing to 26% by 2 years. Eleven (10.2%) patients experienced recurrent disc herniation requiring revision discectomy a mean 10.5 months after surgery. Subjects with larger anular defects (P = 0.019) and with smaller percentage of disc volume removed (P = 0.028) were associated with an increased risk of recurrent disc herniation. Conversely, those from whom greater disc volumes were removed (P = 0.024) had more progressive disc height loss by 6 months after surgery. CONCLUSION: Larger anular defects and less disc removal increased the risk of reherniation. Greater volumes of disc removal were associated with accelerated disc height loss. In the setting of larger anular defects or less aggressive disc removal, concern for recurrent herniation should be increased during outpatient follow-up. In this situation effective anular repair may be helpful.

Silica-immobilized His6-tagged enzyme: alanine racemase in hydrophobic solvent.

A new immobilization method for enzymes is presented to facilitate synthetic applications in aqueous as well as organic media. The enzyme Alanine racemase (AlaR) from Geobacillus stearothermophilus was cloned, overexpressed and then immobilized on a silica-coated thin-layer chromatography plate to create an enzyme surface. The enzyme, fused to a His(6)-tag at its N-terminal, was tethered to the chemically modified silica-coated TLC plate through cobalt ions. The immobilized enzyme showed unaltered kinetic parameters in small-scale stirred reactions and retained its activity after rinsing, drying, freezing or immersion in n-hexane. This practical method is a first step towards a general immobilization method for synthesis applications with any enzyme suitable for His6-tagging.