Total joint arthroplasties (TJAs) of the knee and hip have been considered 2 of the most successful surgical procedures performed to date.
Frailty is defined as increased vulnerability to adverse ...outcomes with physiologic stress.
Preoperative optimization of frailty and metabolic bone conditions, including osteoporosis, vitamin D deficiency, and diabetes, through a multidisciplinary approach can help improve outcomes and minimize costs after TJA.
Lumbar microdiscectomy IS an effective and time-tested neurosurgical procedure. Appropriate patient selection is as important as surgical technique in ensuring good outcome. As with any operation, ...mastery of the relevant anatomy is paramount. We offer the following illustrations to help surgeons appreciate this anatomy: specifically, the relationship between the interspace, the nerve root, and the pedicle as seen during a microdiscectomy.
Axonal regeneration may be hindered following spinal cord injury (SCI) by a limited immune response and insufficient macrophage recruitment. This limitation has been partially surmounted in ...small-mammal models of SCI by implanting activated autologous macrophages (AAMs). The authors sought to replicate these results in a canine model of partial SCI.
Six dogs underwent left T-13 spinal cord hemisection. The AAMs were implanted at both ends of the lesion in 4 dogs, and 2 other dogs received sham implantations of cell media. Cortical motor evoked potentials (MEPs) were used to assess electrophysiological recovery. Functional motor recovery was assessed with a modified Tarlov Scale. After 9 months, animals were injected with wheat germ agglutinin-horseradish peroxidase at L-2 and killed for histological assessment.
Three of the 4 dogs that received AAM implants and 1 of the 2 negative control dogs showed clear recovery of MEP response. Behavioral assessment showed no difference in motor function between the AAM-treated and control groups. Histological investigation with an axonal retrograde tracer showed neither local fiber crossing nor significant uptake in the contralateral red nucleus in both implanted and negative control groups.
In a large-animal model of partial SCI treated with implanted AAMs, the authors saw no morphological or histological evidence of axonal regeneration. Although they observed partial electrophysiological and functional motor recovery in all dogs, this recovery was not enhanced in animals treated with implanted AAMs. Furthermore, there was no morphological or histological evidence of axonal regeneration in animals with implants that accounted for the observed recovery. The explanation for this finding is probably multifactorial, but the authors believe that the AAM implantation does not produce axonal regeneration, and therefore is a technology that requires further investigation before it can be clinically relied on to ameliorate SCI.
The interactions of insulin-like growth factors (IGFs) with the type I IGF receptor are modulated by a family of high-affinity IGF binding proteins (IGFBPs). One of these, IGFBP2, demonstrates a ...striking spatiotemporal relationship with IGF-I during cerebellar and retinal development. IGF-I mRNA is transiently expressed in large projection neurons--cerebellar Purkinje and retinal ganglion cells--while IGFBP2 mRNA is selectively expressed by contiguous neuroglia--Bergmann glia in the cerebellum and Müller cells and astrocytes of the nerve fiber layer in the retina. IGF-I and IGFBP2 gene expression is not only neuroanatomically coordinated but also temporally synchronized, peaking together during the postnatal maturation of these structures. This pattern of IGF system expression suggests that IGFBP2 is closely related to IGF-I's action in the developing nervous system.
Prevention of rebleeding is the most important aspect of the management of hemorrhagic moyamoya disease, because rebleeding causes significant morbidity and mortality.
A 26-year-old male patient with ...a history of moyamoya disease since the age of 3 years and multiple strokes was in a semicomatose state at presentation. He was found to have intraventricular and periventricular hemorrhages abutting the atrium of the right ventricle. His hospital course was complicated by a second hemorrhage. Both bleeding events were believed to be secondary to a ruptured right lateral posterior choroidal aneurysm.
The aneurysm was excised and revealed histopathology consistent with a true saccular aneurysm. Frameless stereotactic guidance was used during surgery to minimize damage to collateral vessels and to shorten the surgical corridor.
The management of hemorrhagic moyamoya disease should be modified based on the source of hemorrhage and its relation to a specifically located aneurysm. In the case of aneurysms arising from the choroidal artery, the general belief is that most of these represent pseudoaneurysms and have a tendency to regress spontaneously. Because of the rebleeding risk, we recommend early intervention in treating ruptured intracranial aneurysms using the least invasive surgical techniques.
Causes of neurological deficits after arteriovenous malformation (AVM) radiosurgery, including hemorrhage, radiation injury, and delayed cyst formation, are described.
Occlusive hyperemia has been ...described as a reason for neurological deterioration after AVM resection. Thrombosis of draining veins or dural sinuses is thought to cause postoperative bleeding or neurological deficits secondary to venous hypertension. In a similar manner, local hemodynamic changes can occur in the brain adjacent to an AVM after radiosurgery if venous outflow is obstructed. Two patients are presented whose cases demonstrate this phenomenon.
Patients can experience clinical worsening after AVM radiosurgery from premature thrombosis of draining veins. Local hemodynamic changes could explain why imaging changes thought to be radiation related occur more frequently after radiosurgery of AVMs than of tumors.
The decision to pursue surgery is often complicated in older adults. A multidisciplinary, shared approach to decision-making may improve communication between patients and their providers and ...facilitate complex risk assessment. We describe a case of an older adult presenting for complex surgery in which the preoperative anesthesia clinic visit was used to facilitate involvement of the geriatrics service. This multidisciplinary approach allowed for re-evaluation and reiteration of risks and benefits, in-depth discussion of the patient's values and goals, and recommendations for care teams downstream in the patient's surgical pathway to ensure treatment consistent with patient goals and clinical recommendations.
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