Decompressive hemicraniectomy and cranioplasty using subcutaneously preserved autologous bone flaps versus synthetic implants: perioperative outcomes and cost analysis.

OBJECTIVE: It has not been well-elucidated whether there are advantages to preserving bone flaps in abdominal subcutaneous (SQ) tissue after decompressive hemicraniectomy (DHC), compared to discarding bone flaps. The authors aimed to compare perioperative outcomes and costs for patients undergoing autologous cranioplasty (AC) after DHC with the bone flap preserved in abdominal SQ tissue, and for patients undergoing synthetic cranioplasty (SC). METHODS: A retrospective review was performed of all patients undergoing DHC procedures between January 2017 and July 2021 at two tertiary care institutions. Patients were divided into two groups: those with flaps preserved in SQ tissue (SQ group), and those with the flap discarded (discarded group). Additional analysis was performed between patients undergoing AC versus SC. Primary end points included postoperative and surgical site complications. Secondary endpoints included operative costs, length of stay, and blood loss. RESULTS: A total of 248 patients who underwent DHC were included in the study, with 155 patients (62.5%) in the SQ group and 93 (37.5%) in the discarded group. Patients in the discarded group were more likely to have a diagnosis of severe TBI (57.0%), while the most prevalent diagnosis in the SQ group was malignant stroke (35.5%, p < 0.05). There were 8 (5.2%) abdominal surgical site infections and 9 (5.8%) abdominal hematomas. The AC group had a significantly higher reoperation rate (23.2% vs 12.9%, p = 0.046), with 11% attributable to abdominal reoperations. The average cost of a reoperation for an abdominal complication was $40,408.75 ± $2273. When comparing the AC group to the SC group after cranioplasty, there were no significant differences in complications or surgical site infections. There were 6 cases of significant bone resorption requiring cement supplementation or discarding of the bone flap. Increased mean operative charges were found for the SC group compared to the AC group ($72,362 vs $59,726, p < 0.001). CONCLUSIONS: Autologous bone flaps may offer a cost-effective option compared to synthetic flaps. However, when preserved in abdominal SQ tissue, they pose the risk of resorption over time as well as abdominal surgical site complications with increased reoperation rates. Further studies and methodologies such as cryopreservation of the bone flap may be beneficial to reduce costs and eliminate complications associated with abdominal SQ storage.

Current uses, emerging applications, and clinical integration of artificial intelligence in neuroradiology.

Artificial intelligence (AI) is a branch of computer science with a variety of subfields and techniques, exploited to serve as a deductive tool that performs tasks originally requiring human cognition. AI tools and its subdomains are being incorporated into healthcare delivery for the improvement of medical data interpretation encompassing clinical management, diagnostics, and prognostic outcomes. In the field of neuroradiology, AI manifested through deep machine learning and connected neural networks (CNNs) has demonstrated incredible accuracy in identifying pathology and aiding in diagnosis and prognostication in several areas of neurology and neurosurgery. In this literature review, we survey the available clinical data highlighting the utilization of AI in the field of neuroradiology across multiple neurological and neurosurgical subspecialties. In addition, we discuss the emerging role of AI in neuroradiology, its strengths and limitations, as well as future needs in strengthening its role in clinical practice. Our review evaluated data across several subspecialties of neurology and neurosurgery including vascular neurology, spinal pathology, traumatic brain injury (TBI), neuro-oncology, multiple sclerosis, Alzheimer's disease, and epilepsy. AI has established a strong presence within the realm of neuroradiology as a successful and largely supportive technology aiding in the interpretation, diagnosis, and even prognostication of various pathologies. More research is warranted to establish its full scientific validity and determine its maximum potential to aid in optimizing and providing the most accurate imaging interpretation.

Treatment of In-Stent Stenosis Following Flow Diversion of Intracranial Aneurysms with Cilostazol and Clopidogrel.

In-stent stenosis is a feared complication of flow diversion treatment for cerebral aneurysms. We present 2 cases of patients treated with pipeline flow diversion for unruptured cerebral aneurysms. Initial perioperative dual antiplatelet therapy (DAPT) consisted of standard aspirin plus clopidogrel. At 6-month follow-up cerebral angiography, the patients were noted to have developed significant in-stent stenosis (63% and 53%). The patients were treated with cilostazol and clopidogrel for at least 6 months. Subsequent angiography at 1-year post-treatment showed significant improvement of the in-stent stenosis from 63% to 34% and 53% to 21%. The role of cilostazol as treatment of intracranial in-stent stenosis has not been previously described. Cilostazol's vasodilatory effect and suppression of vascular smooth muscle proliferation provides ideal benefits in this setting. Cilostazol plus clopidogrel may be a safe and effective alternative to standard DAPT for treatment of in-stent stenosis following flow diversion and warrants further consideration and investigation.

Do bicortical diaphyseal array pins create the risk of periprosthetic fracture in robotic-assisted knee arthroplasties?

BACKGROUND: Optical array placement for robotic-assisted knee replacement introduces the rare, but real risk of periprosthetic fracture. The purpose of this retrospective study was to review the incidence of fracture with the conventional technique of bicortical diaphyseal pin placement. We also evaluated a modified method of unicortical periarticular pin placement to mitigate this risk. METHODS: We reviewed 2603 knee arthroplasties that were performed between June 2017 and December 2019. The conventional bicortical diaphyseal technique was used in 1571 knees (bicortical diaphyseal group) and the unicortical periarticular technique was used in 1032 knees (unicortical periarticular group). RESULTS: A more than 1-year follow-up revealed that 3 femoral shaft fractures (0.19%) occurred in the bicortical diaphyseal group and no fracture took place in the unicortical periarticular group. There was no array loosening in either group. CONCLUSIONS: The modified unicortical periarticular pin placement is a reliable technique for computer-navigated and robotic-assisted knee arthroplasties. It may be associated with a lower incidence of postoperative femoral shaft fractures, compared to conventional bicortical diaphyseal pinning.

Salvage of Failed Femoral Neck Fracture Fixation with Conversion Total Hip Arthroplasty Using the Direct Anterior Approach.

PURPOSE: Failed femoral neck fracture (FNF) fixation with in situ pinning presents a surgical challenge. Osteoporotic bone, retained hardware, and a typically elderly population magnify the risks of surgery. Here, outcomes of conversion total hip arthroplasty (THA) using two separate incisions in these high-risk patients were examined. MATERIALS AND METHODS: Medical records for 42 patients with a prior history of FNF fixation who underwent conversion THA with hardware removal between 2009 and 2019 were retrospectively reviewed. Surgery was performed by a single surgeon at a single institution. All patients underwent hardware removal followed by direct anterior approach (DAA) THA using two separate incisions. Clinical outcomes, radiographic findings, and perioperative morbidity and mortality are reported. RESULTS: Clinically, there were no postoperative dislocations, periprosthetic fractures, or infections at follow-up. After a mean follow-up of 4 years, the mean hip disability and osteoarthritis outcome score, junior (HOOS, Jr) was 91. Radiographically, the mean postoperative cup abduction was 44 degrees and the mean cup anteversion was 21 degrees with an improvement in preoperative leg length discrepancy. Perioperative complications included one case of immediate foot drop and two readmissions for medical issues. One patient died one month after conversion THA. CONCLUSION: Salvage of failed FNF treatment may be managed with conversion THA and DAA with a separate incision for hardware removal. Preservation of posterior soft tissues using a DAA and intraoperative fluoroscopy may mitigate well-known complications related to fracture and dislocation. While favorable clinical outcomes are possible, salvage surgery is still not without substantial surgical and medical risks.

Modified Two-Stage Exchange for Periprosthetic Joint Infection in UKA.

Periprosthetic joint infection (PJI) is a rare complication following unicompartmental knee arthroplasty (UKA), and current management guidelines are still evolving. This report presents a novel surgical technique of resection arthroplasty with an articulated hemispacer as part of a 2-stage exchange protocol. A 66-year-old man developed a culture-negative PJI four months after a medial UKA. Rather than conventional full resection arthroplasty, the patient underwent partial resection with preservation of the lateral and patellofemoral compartments to maintain vascularized bone stock. An articulating hemispacer fashioned from the old implants after sterilization was reimplanted medially to preserve function during the course of antibiotic treatment. After successful eradication of infection, the patient underwent an uncomplicated conversion total knee replacement facilitated by prior preservation of bone stock. No stems or augments were needed. Therefore, a partial resection arthroplasty with an articulating hemispacer used in a 2-stage exchange protocol may be a reasonable option to eradicate infection and maintain function. In future cases of infected UKA, this technique warrants further consideration and investigation.

Management of failed UKA to TKA: conventional versus robotic-assisted conversion technique.

BACKGROUND: Failure of unicompartmental knee arthroplasty (UKA) is a distressing and technically challenging complication. Conventional conversion techniques (CCT) with rods and jigs have produced varying results. A robotic-assisted conversion technique (RCT) is an unexplored, though possibly advantageous, alternative. We compare our reconstructive outcomes between conventional and robotic methods in the management of failed UKA. METHODS: Thirty-four patients with a failed UKA were retrospectively reviewed. Patients underwent conversion total knee arthroplasty (TKA) with either a CCT or RCT. Seventeen patients were included in each group. All procedures were done by a single surgeon at a single institution, with a mean time to follow-up of 3.6 years (range, 1 to 12). The primary outcome measures were the need for augments and polyethylene thickness. Secondary outcome measures were complications, need for revision, estimated blood loss (EBL), length of stay, and operative time. RESULTS: The mean polyethylene thickness was 12 mm (range, 9 to 15) in the CCT group and 10 mm (range, 9 to 14) in the RCT groups, with no statistical difference between the two groups (P = 0.07). A statistically significant difference, however, was present in the use of augments. In the CCT group, five out of 17 knees required augments, whereas none of the 17 knees in the RCT group required augments (P = 0.04). Procedurally, robotic-assisted surgery progressed uneventfully, even with metal artifact noted on the preoperative computerized tomography (CT) scans. Computer mapping of the residual bone surface after implant removal was a helpful guide in minimizing resection depth. No further revisions or reoperations were performed in either group. CONCLUSIONS: Robotic-assisted conversion TKA is technically feasible and potentially advantageous. In the absence of normal anatomic landmarks to guide conventional methods, the preoperative CT scans were unexpectedly helpful in establishing mechanical alignment and resection depth. In this limited series, RCT does not seem to be inferior to CCT. Further investigation of outcomes is warranted.