Postoperative Computed Tomography Scans Research Articles

Effects of ileal conduit length on long-term kidney function decline after total pelvic exenteration for colorectal cancer.

Understanding of kidney function decline (KFD) after pelvic exenteration (PE) for colorectal cancer remains limited, and the effects of a long ileal conduit (IC) on kidney disorders are unclear. The aim of this study was to investigate long-term kidney function following PE in colorectal cancer and to evaluate the effects of IC length on KFD. This was a retrospective, single-centre cohort study. KFD was defined as a decline in estimated glomerular filtration rate (eGFR) of ≥30% compared with preoperative data. IC length was measured from a postoperative computed tomography scan. The primary endpoint was the number of patients with KFD 5 years after surgery. The rate of decline of eGFR, cumulative KFD incidence and correlation between IC length and rate of decline of eGFR were also analysed. The patients were divided into two groups (short IC and long IC) based on an IC length of 20 cm. Forty-three patients were included in the analysis. Fourteen (33%) and 29 (67%) patients were included in the short- and long-IC groups, respectively. The long-IC group was significantly more likely to be diagnosed with KFD within 5 years than the short-IC group (51% vs. 14%, p = 0.023). Multivariate analyses revealed that a longer IC was identified as an independent risk factor for KFD (hazard ratio 4.140, 95% CI 1.035-16.560, p = 0.045). Pearson's correlation and linear regression analyses demonstrated a significant association between IC length and rate of decline of eGFR (r = 0.466, p = 0.002). A significant number of patients with colorectal cancer have decreased kidney function after PE. A longer conduit may impair kidney function.

Massive pneumocephalus after Valsalva maneuver in sphenoidal meningocele.

Pneumocephalus, defined as the presence of gas within the intracranial space, typically results from head trauma, surgery, or diagnostic/therapeutic procedures that disrupt the dura. However, spontaneous or non-traumatic pneumocephalus is rare. This video article presents a case report of a 64-year-old woman referred to the Department of Otolaryngology with a severe frontal headache and clear nasal discharge (rhinorrhea) after performing the Valsalva maneuver to relieve ear fullness. The patient had previously been diagnosed with sphenoidal meningocele and was awaiting skull base reconstruction surgery. A computed tomography (CT) scan of the brain and paranasal sinuses revealed significant pneumocephalus, with a defect in the sellar floor and cerebrospinal fluid (CSF) pooling in the sphenoid sinus. An endoscopic trans-sphenoidal repair of the CSF leak was promptly performed, and a post-operative CT scan showed complete resolution of the pneumocephalus. At the 2-month follow-up, the defect had healed optimally, with no intracranial complications observed. Pneumocephalus is a rare clinical condition, and prompt, accurate diagnosis, along with early intervention, is crucial to prevent neurological complications.

Exploring 3D Modeling for Enhanced Visualization and Analysis of Pediatric Pelvic Ring Fractures: A Pilot Study

Introduction Pediatric pelvic fractures are high energy injuries that present substantial treatment challenges due to their propensity for plastic deformation, complex fracture patterns, and lack of consensus on surgical indications. There is potential for negative long-term outcomes in patients with residual deformity, but our understanding of acceptable alignment is limited. Plain radiographs and computed tomography (CT) are frequently employed for pre- and post-operative assessment of injury patterns, but are limited to two-dimensional analysis. Three dimensional (3D) modeling offers an opportunity for improved assessment of pelvic anatomy. Methods Two pediatric patients who sustained unstable pelvic ring injuries requiring operative fixation, with both pre- and post-operative CT scans, were identified from an existing IRB-approved trauma database. Utilizing 3D Slicer, 3D segmentations were rendered from DICOM data and specific landmarks were identified to calculate deformity pre- and post-operatively including displacement at the sacroiliac (SI) joints, pubic symphysis, and iliac crest. A modified Keshishyan deformity index was also calculated. Mesh overlay was performed using Autodesk Maya in x, y and z planes to provide visual representation of post-operative changes. Results 3D renderings successfully illustrated complex pelvic fractures in a 9 year old female and 12 year old. Measurements made on 3D models showed similar improvements in diastasis and symmetry to measurements made in standard 2D imaging, but with generally smaller magnitudes. Graphic overlap allow for sophisticated representation of improvement in deformity. Measurements on plain radiographs and 2D CT differed from 3D measurements by anywhere from 0.1 mm to 6.7 mm. Conclusion This proof-of-concept pilot study demonstrates that 3D renderings enhance the ability to measure displacement and deformity in pediatric pelvic trauma for both pre-operative planning and post-operative evaluation. Future applications of this technology include evaluation of pelvic deformity remodeling after trauma in both operative and non-operatively treated pediatric patients.

Managing Late-Onset ERF-Related Craniosynostosis With Cranial Vault Distraction Osteogenesis

Introduction: ETS2 Repressor Factor (ERF) gene-related craniosynostosis is a rare condition characterized by pre- and/or post-natal fusion of 1 or more cranial sutures. In this report, we present our center’s experience managing ERF-related craniosynostosis in 2 patients with intracranial hypertension using cranial vault distraction osteogenesis (CVDO). Methods: Both patients underwent genetic testing and 24 hour intracranial pressure monitoring prior to surgery. Additionally, they were followed with regular clinical and dilated eye exams for a minimum of 2 years after surgery. Morphological and volumetric analysis were performed using pre- and post-operative computed tomography (CT) scans. Results: Both patients presented with late-onset, multisuture craniosynostosis. Patient 1 underwent lateral expansion of 2 frontoparieto-occipital bone segments at 5 years of age. A total expansion of 28 mm was performed (14 mm on each side) over a period of 12 days. Pre- and post-operative CIs were 69.3 and 81.3, respectively, and volumetric analysis revealed a 24.4% increase in his intracranial volume. Patient 2 underwent posterior expansion of a single parieto-occipital bone segment at 4 years and 10 months of age. A total expansion of 25.2 mm was performed over a period of 21 days. Pre- and post-operative CIs were 72.8 and 69.9, respectively. Volumetric analysis could not be performed owing to the poor resolution of the patient’s post-operative CT scan that was obtained from an outside institution. Both patients had their distractors removed following a 2 month consolidation period. No complications, signs of intracranial hypertension, or bony defects were noted for both patients at 2 years post-operatively. Conclusions: CVDO provides a tested option with excellent outcomes for treating patients with ERF-related craniosynostosis. Continued education of clinicians and families regarding ERF-related craniosynostosis is key to ensuring that patients with this genetic mutation promptly establish care for close surveillance and, in turn, prompt treatment if necessary.

Percutaneous hallux fusion with calcaneus bone autograft: a retrospective cohort study of clinical and radiographic outcomes.

In the case of end-stage hallux rigidus, first metatarsophalangeal (MTP) joint arthrodesis is the gold-standard and is traditionally performed via an open approach. However, complications such as nonunion have been reported to be as high as 30%. Recently, there have been reports demonstrating a percutaneous approach to be effective and safe. Forty-nine patients with end-stage hallux rigidus underwent percutaneous first MTP joint arthrodesis with calcaneus autograft performed by a single surgeon. Each patient underwent a minimum of 24 month clinical and radiographic follow up, including 3 month post operative computed tomography scans. Clinical outcomes were assessed using the Visual Analog Scale (VAS) and Foot Function Index (FFI) preoperatively and at final follow-up. Mean follow-up was 27.3 months. Bone union was observed in 46 patients (93.9%). Mean time to union was 3.1 months. Nonunion rate was 6.1%. Overall complication rate was 12.2%. Mean pre- and postoperative VAS scores were 7.5 and 0.2, respectively (P < .0001). Mean pre- and postoperative total FFI values were 56.3 and 15.7 (P < .0001), respectively. Patient satisfaction after the procedure was 93.9%. Observed union rate is comparable to the average fusion rate previously reported for open and minimally invasive procedure union rates. Mean time to union was observed to be comparable to open procedures union time. Observed overall complication rate is similar to those reported for open techniques as well. Patient reported outcomes demonstrated a significant reduction in postoperative VAS and FFI for the percutaneous metatarsophalangeal arthrodesis with calcaneus bone autograft. Patient satisfaction rates compared favorably to those reported following open surgery.

Importance of Post-Reduction CT Scans in Posterior and Transverse Posterior Wall Acetabular Fracture-Dislocations.

To report the frequency of patients with pre- and post-reduction computed tomography (CT) scans associated with acetabular fracture-dislocations and the change of associated intra-articular fragments occurring with joint reduction. Design: Retrospective case series. Regional Level 1 trauma center. Patients who sustained an OTA/AO 62A1 and 62B1 posterior wall or transverse posterior wall acetabular fracture-dislocations with pre- and post-reduction CT imaging from February 2020 until July 2023. Intra-articular fragments were identified and change in position (fossa to cranial, intra-articular to extra-articular, etc.) noted from pre- to post-reduction scans. Operative reports and post-operative CT scans were reviewed to determine the frequency of fragment retrieval. 119 out of 394 (30.2%) patients meeting fracture pattern inclusion received a CT scan prior to hip reduction. Of the 394 patients, 100 (25.9%) had pre- and post-reduction CT scans and were studied (average age of 35.5 years (range 16 - 87 years), 59 male). 45 of 100 patients (45%) had pre-reduction CT imaging demonstrating the presence of intra-articular fragment(s). 30 of 45 patients with a pre-reduction intra-articular fragment (66.7%) had an intra-articular fragment location change during the reduction. Of the 55 patients who did not have an intra-articular fragment on pre-reduction imaging, 28 of 55 (50.9%) had at least 1 intra-articular fragment on the post-reduction CT. Complete fragment retrieval was performed in 71.4% of patients. The study demonstrated 30.2% of patients with posterior wall and transverse posterior wall acetabular fracture-dislocations received a CT scan prior to hip reduction. It was common to find intra-articular fragments on the post-reduction CT in patients who did not have them on the pre-reduction CT. Obtaining and scrutinizing the post-reduction CT scan provided accurate knowledge of the location of all osseous fragments associated with the fracture-dislocations which facilitated thorough preoperative planning, intraoperative implementation, and hopeful long-term patient outcomes. Prognostic Level IV.

Clinical outcome and complications after simultaneous bilateral medial opening-wedge high tibial osteotomy

BackgroundThe literature provides limited evidence regarding postoperative outcomes and complications following simultaneous bilateral medial opening-wedge high tibial osteotomy (MOWHTO). This study aimed to investigate the clinical outcomes and complications associated with simultaneous bilateral MOWHTO. MethodsWe retrospectively evaluated 72 knees from 36 patients (mean age, 58.6 ± 8.2 years) who underwent simultaneous bilateral MOWHTOs between December 2011 and January 2021. Locking compression plates were used for simultaneous bilateral MOWHTOs. The Oxford Knee Score (OKS) was used to assess clinical outcomes at the last follow up. Complications (lateral hinge fracture (LHF), nonunion, and loss of correction) were evaluated using postoperative serial plain radiography and computed tomography (CT). ResultsAt the last follow up (range, 2.0–11.1 years), the mean OKS for the 72 knees was 36.8 ± 10.4. According to the OKS, 42 knees (58.3%) scored ’excellent’, 16 (22.2%) scored ‘good’, eight (11.1%) scored ‘moderate’, and six (8.3%) scored ‘poor’. LHFs occurred in 11 of the 72 knees (15.3%). Among these, five LHFs were identified on postoperative plain radiographs and CT scans (acute LHFs), whereas six fractures were identified only on follow up plain radiographs (delayed LHFs). Loss of correction occurred in one patient with delayed LHFs. The patient required an additional surgical treatment to achieve bone healing at the osteotomy site. ConclusionSimultaneous bilateral MOWHTO is a viable treatment option for patients with bilateral medial osteoarthritis of the knee joint. Serial plain radiographs at short-term intervals are recommended to detect delayed LHFs and prevent complications such as fixation failure and loss of correction.

Risk of neurologic deficit in medially breached pedicle screws assessed by computed tomography: a systematic review.

Pedicle screws are commonly used for vertebral instrumentation, and a postoperative computed tomography (CT) scan is used to evaluate their position within the pedicle. Medial pedicle screw breaching occurs in 20%-40% of cases. This study investigated the correlation between radiographically evident medial breaching and the incidence of nerve injury, shedding light on the clinical implications. A literature search was conducted on biomedical databases regarding neurologic deficits associated with medially breached pedicle screws with pre-defined inclusion and exclusion criteria. The methodology of the included studies was analyzed, and a systematic review and meta-analysis were performed to investigate the correlation between medial breach on axial CT and clinical neurologic deficits. Our study included thirteen articles. Medial breaches <2 mm caused no neurologic deficit. Medial breaches of 2-4 mm increased the risk of neurologic deficit by 83%, with a risk ratio of 0.17. Breaches exceeding 4 mm increased the risk by 90%, with a risk ratio of 0.1, and were associated with radiculopathy or muscle weakness in 25%-100% of cases. Medial pedicle screw breaches <2 mm are safe, carrying no risk of neurologic injury. Breaches exceeding ≥2 mm significantly increase this risk. For patients experiencing new neurologic deficit (sensory or motor) after pedicle screw instrumentation, particularly in lumbar vertebrae, a postoperative axial CT scan is recommended to identify breaches exceeding 2 mm as the potential cause of neurologic deficit.

Cancellous Grafting Versus Corticocancellous Graft With Volar Locked Plating for Scaphoid Waist Fracture Nonunion: An Evaluation of Early Bony Bridging.

Achieving bony union in scaphoid nonunion fractures is challenging. Various bone grafts have been studied using headless compression screws (HCS) fixation. However, the impact of bone graft choice on bone healing with volar locking plates (VLP) use is less clear. This study evaluates osseous bridging using packed cancellous grafting versus corticocancellous grafting when used during scaphoid waist nonunion repair with volar plating. A retrospective case series was performed of 22 consecutive patients with a scaphoid waist fracture nonunions that were treated with VLP fixation and bone autografts. Inclusion criteria required ≥90-day follow-up clinical examination and postoperative computed tomography (CT) scan. Graft types included corticocancellous or packed cancellous autograft harvested from the radius or iliac crest. Amount of bone healing and presence of residual dorsal intercalated segmental instability were determined by 3 fellowship-trained hand surgeons. Twenty-two patients with scaphoid fracture nonunions that met study inclusion criteria were evaluated. Postoperative CT scan showed osseous bridging in 95% (21/22) of patients. Despite less time between surgery and the final follow-up CT scan (102.7 ± 59 days for packed cancellous autografts vs 133.6 ± 73 days for corticocancellous autografts), the packed cancellous autograft group displayed higher osseous bridging percentages compared with the corticocancellous graft (80.7% ± 17% vs 47.8% ± 35%, P = .013). Nearly all patients displayed osseous bridging on postoperative CT scan with VLP and autograft use. However, study findings suggest that packed cancellous autograft use displayed more robust early healing.

Dysplastic ganglion cell tumor of the right cerebellum: A case report and literature review.

This study aims to present a case of cerebellar dysplastic ganglioneuroma, which is commonly referred to as Lhermitte-Duclos disease (LDD). Furthermore, the study aims to provide an extensive review of the essential aspects of LDD, thereby providing essential information for its accurate diagnosis and effective treatment. A 54-year-old woman was admitted with symptoms of headache, facial numbness, and a visible cerebellar mass. Imaging studies revealed specific features such as the "tiger stripe sign" on magnetic resonance imaging, including hydrocephalus compression and abnormal vasculature. The diagnosis of LDD was made. The cerebellar mass was resected via a paracentral approach. The patient underwent surgery for a cerebellar dysplastic ganglion cell tumor (WHO grade I), confirmed by postoperative pathology. Despite sub-complete resection with minor residuals, the patient experienced significant improvement in symptoms. A postoperative computed tomography scan revealed a large cavity with frontal lobe hemorrhage. PTEN gene testing was recommended but declined due to financial constraints. The patient was discharged without complications. LDD presents both benign and tumor characteristics, with a low likelihood of malignancy. Total resection is the recommended treatment, although challenges in complete excision may lead to recurrence. The importance of considering Cowden syndrome and genetic testing, particularly the PTEN gene, in patients with LDD, is emphasized. Long-term follow-up care is crucial for monitoring recurrence and related conditions.

Distal Pancreatectomy with Celiac Axis and Venous Resection with Hepatic Artery and Venous Reconstruction (DP-CARV) for Locally Advanced Pancreatic Adenocarcinoma.

Surgery has recently been introduced into the multimodal management of patients with locally advanced pancreatic adenocarcinomas (LAPCs) thanks to the major pathological response seen with the advent of the multiagent regimen FOLFIRINOX. Distal pancreatectomy with celiac axis resection (DP-CAR) may be complicated by ischemic liver and gastric events.1,2 Common hepatic artery reconstruction may prevent the occurrence of ischemic complications and can be an alternative to preoperative embolization of the celiac trunk.3 METHODS: The patient was a 65-year-old with LAPC of the pancreatic body, with infiltration of the celiac trunk, the splenoportal venous confluence, and the Treitz angle. Preoperative induction chemotherapy with FOLFIRNOX was administered over 12 cycles, resulting in radiological stability and normal carbohydrate antigen (CA) 19-9 levels. Positron emission tomography showed isolated activity of the tumor without distant metastasis. A DP-CARV procedure was performed, and a single saphenous graft was used to reconstruct the common hepatic artery and to create a venous patch to repair the venous confluence. The angle of the Treitz, along with the third and fourth duodenum, were resected and a duodenojejunal anastomosis on the second duodenal portion was performed. The left gastric artery was not reconstructed. Postoperative course was favorable but was complicated by a hematoma of the right groin necessitating evacuation. Pathology showed a pT4N2R0 pancreatic adenocarcinoma. The postoperative computed tomography scan showed no collection and patency of reconstructed vessels. Six months later, the patient is alive and disease-free, with patent reconstructed vessels. Common hepatic artery reconstruction during DP-CAR represents a safe surgical option to reduce ischemic events related to celiac trunk resection, particularly in the FOLFIRINOX era. This technique integrated the surgical armamentarium of surgeons dealing with LAPC.

Bony realignment in surgically treated orbital blowout fractures based on computed tomography

BackgroundThis study investigated postoperative bony realignment using follow-up computed tomography (CT) scans of patients with blowout fracture repair using an alloplastic implant.MethodsThis is a retrospective study of patients who underwent surgical treatment for orbital blowout fractures and had follow-up CT at least 4 months after the surgery. Preoperative, early, and late postoperative CT scans were obtained to assess the outcome measures including reduction completeness, reconstructed wall composition, and presence of implant-related complications. CT scans of patients with complications were compared with those of patients without complications for radiologic changes.ResultsOur study comprised 48 orbits from 48 patients. The mean age was 28.1 years, the mean time from injury to surgery was 18.3 days, and the mean time from surgery to the latest CT scan was 47.2 months (4–212 months). Most orbits (n = 41, 91.7%) showed complete reduction postoperatively. Among the 36 patients without complications, 89% showed total and 11% showed partial bony coverage. Among the 12 patients with complications, 42% showed total, 42% showed partial, and 16% showed no bony coverage. Partial or no bony coverage was noted in 11.1% (4/36) of patients without complications and in 58.3% (7/12) with complications. Reconstructed wall composition was significantly related to the presence of complications (p = 0.002). The group with total bony coverage was younger than the group with partial or no bony coverage (p = 0.048).ConclusionsA displaced bone in the sinus is repositioned in the early postoperative stage along with the implant substantially. Partial or no bony coverage was related to the complicated cases. Young age was found to be a favoring factor for total bony coverage over the implant.

Evaluation of Preoperative Factors That Affect the Alpha Angle of Screw Insertion After the Open Latarjet Procedure.

The open Latarjet procedure yields excellent results as a treatment for anterior shoulder instability. The position of the bony fragment and the insertion angle of the screw (the alpha angle) are critical factors for a successful procedure. The alpha angle is considered overangulated at >25°, which is associated with poor bone fixation and healing. To assess preoperative patient anatomic factors that affect the alpha angle in the Latarjet procedure for anterior shoulder instability. Case-control study; Level of evidence, 3. In this retrospective study, 76 patients who underwent the open Latarjet procedure between October 2009 and December 2023 were included. Postoperative computed tomography scans were reviewed for the alpha angle, and patients were classified into 2 groups: group 1 (alpha angle ≥25°) and group 2 (alpha angle <25°). Preoperative patient characteristics and radiological parameters obtained from preoperative computed tomography scans were analyzed and compared between groups 1 and 2. We developed a novel method to measure the depth of the chest and the angle between the deltopectoral interval and the plane of screw insertion. We also measured the thickness of the pectoralis major and subscapularis muscles. Of the 76 patients in this study, 41 and 35 patients were included in groups 1 and 2, respectively. The mean alpha angles of groups 1 and 2 were 36° and 12°, respectively, and the body mass index was significantly higher in group 1 (P < .001). In addition, group 1 had a significantly longer distance from the anterior edge of the glenoid to the skin margin of the deltopectoral interval (P < .001). The angle between the deltopectoral interval and the plane of screw insertion (traction angle) was significantly larger in group 1 (P < .001), and the pectoralis major and subscapularis muscles were thicker in group 1 (P = .017 and P = .032, respectively). The alpha angle after the Latarjet procedure was strongly related to the patient's weight, body mass index, depth of the chest, and the angle between the deltopectoral interval and the plane of screw insertion. To our knowledge, this is the first study in which the preoperative factors that facilitate proper screw fixation in the Latarjet procedure are reported.

X-ray guided anatomy-based fitting: The validity of OTOPLAN.

Anatomy-based fitting (ABF) for cochlear implant users is a new era that seeks improved outcomes. Recently, different imaging modalities, such as plain X-rays, have been proposed to build the ABF as an alternative to the computed tomography (CT) scan. This study aimed to assess the feasibility and validity of OTOPLAN® software in building ABF using plain X-ray imaging. A retrospective evaluation of postoperative CT scans and plain X-ray post-op images of 54 patients was analyzed using the OTOPLAN® software. The post-op analysis was done for the angular insertion depth (AID) and center frequency of each electrode contact using both imaging modalities. Moreover, inter-rater reliability was assessed for measurements obtained from CT scans and plain X-ray images. Non-significant statistical and clinical mismatches were detected when comparing the AID and center frequency measurements assessed using CT and X-rays. The absolute difference between CT and X-ray approaches ranged from 0.0 to 4.6 degrees for AID and 0.2 to 0.5 semitone for frequency. Moreover, the AID and the frequency measurements from CT and X-ray images demonstrated almost perfect agreement between the raters. The inter-observer reliability for CT scans showed that the intraclass correlation coefficient (ICC) exceeded 0.97 for AID and 0.95 for the frequency across all electrode contacts. Our results demonstrated the validity and reliability of using post-operative X-ray images by OTOPLAN® software to build Anatomy-based Fitting maps.

Speech Perception Outcomes with the Anatomy-Based Fitting Map among Experienced, Adult Cochlear Implant Users: A Longitudinal Study

Plain Language SummaryThe goal of this experimental, long-term study is to evaluate speech perception over 6 months of the use of anatomy-based fitting (ABF), a relatively novel programming technique. While normal fitting uses the manufacturer’s default frequency distribution algorithm, ABF programming in cochlear implant (CI) processors uses the position of the intracochlear electrode to disperse the associated frequencies. This indicates that the frequency properties of the nerves being stimulated by the electrode contact point match the frequency distribution caused by ABF. Consequently, it is hypothesized that ABF enhances auditory perception by improving place-pitch cue precision. Nine CI ears from eight experienced adult CI users were included in this investigation. Postoperative computed tomography scans were used in a surgical planning software called Otoplan to detect the locations of the implanted electrodes and corresponding center frequencies. To create the anatomy-based frequency bands, data from Otoplan were transferred into the Maestro 9.0 CI fitting program. Nonsense syllables with consonant-vowel-consonant (CVC) identification scores in quiet and in noise (+5 dB SNR) were compared in the beginning, 3, and 6 months after ABF use. The findings showed that vowels and consonants were perceived more clearly with the ABF map, particularly for sounds that had voicing signals. The outcomes also suggested that ABF would be more advantageous for speech recognition in the presence of noise. Overall, the findings imply that, at least for experienced adult CI users, treating place mismatch with an ABF map could enhance speech perception.

Robotic pedicle screw placement with 3D MRI registration: moving towards radiation free robotic spine surgery

BACKGROUND CONTEXTPreoperative imaging for lumbar spine surgery often includes magnetic resonance imaging (MRI) for soft tissues and computer tomography (CT) for bony detail. While CT scans expose patients to ionizing radiation, whereas MRI scans do not. Emerging MRI techniques allow CT-like 3-dimensional (3D) visualization of bony structures, potentially removing the need for ionizing radiation from CT scans. PURPOSEThis study aims to explore the accuracy of robot-assisted lumbar pedicle screw placement based on preoperative CT-like 3D MRI as the data source for robotic registration. STUDY DESIGNHuman cadaveric study. METHODSCT-like 3D MRI scans of the lumbar spine were acquired in ten human cadavers. A robotic navigation platform was used to plan and navigate pedicle screw placement based on the CT-like 3D MRI. Postoperative CT scans assessed the accuracy of screw positioning compared to preoperative planning based on the Gertzbein-Robbins scale (GRS) and by direct measurement (mm). RESULTSA total of 100 lumbar pedicle screws were robotically placed in ten cadavers (L1 through L5 bilaterally) based on CT-like 3D MRI. On postoperative CT evaluation, 99.0% of the positioned screws achieved an acceptable grade on the GRS (Grade A: n=89 or Grade B: n=10), with 89.0% classified as Grade A and 10.0% as Grade B. Meaning that 89.0% of screws were fully contained within the pedicle (GRS A), and 10% had a minor cortical breach <2 mm (GRS B). The median deviation from the planned trajectory was 0.2 mm (axial IQR: 0.1 to 0.5 mm; sagittal: IQR: 0.1 to 0.4 mm), in both axial and sagittal planes. CONCLUSIONThis study showed that image registration of CT-like 3D MRI for robotic-assisted spine surgery is technically feasible and that accurate pedicle screw placement can be achieved without preoperative CT. Each CT-like 3D MRI was successfully registered for robotic navigation. CLINICAL SIGNIFICANCEThe results suggest that CT-like 3D MRI has the potential to be a radiation-free alternative for preoperative planning and navigation in lumbar spine instrumentation procedures.

Lipoprotein(a) and High-Sensitivity C-Reactive Protein Compound the Risk of Hypoattenuating Leaflet Thickening After Transcatheter Aortic Valve Replacement.

The mechanism for hypoattenuating leaflet thickening (HALT) after transcatheter aortic valve replacement is still not well elucidated, and the role of Lp(a) (lipoprotein[a]) and hs-CRP (high-sensitivity C-reactive protein) has rarely been studied. This study sought to test the hypothesis that the risk of HALT is associated with an elevated level of Lp(a) or hs-CRP. A total of 307 consecutive individuals who underwent a transcatheter aortic valve replacement procedure were included. All patients received their first postoperative computed tomography scans within 12 months, and raw data were analyzed on 3mensio software. HALT was defined as visually identified increased leaflet thickness with typical meniscal appearance and at least 2 different multiplanar reformation projections. Associations of Lp(a) or hs-CRP with the risk of HALT were evaluated using multivariable logistic regression analysis. The incidence of HALT within 12 months after transcatheter aortic valve replacement in this study was 36.2%, and the risk of HALT was associated with higher baseline Lp(a) (the multivariable adjusted odds ratio [OR] for every 10 mg/dL change was 1.18 [95% CI, 1.09-1.29]) and hs-CRP level (the multivariable adjusted OR for every 1 mg/L change was 1.08 [95% CI, 1.00-1.27]). Compared with individuals out of the top 25th percentile for both Lp(a) and hs-CRP, the multivariable adjusted OR for HALT was 4.74 (95% CI, 1.65-14.37) for the top 25th percentile. This result remained consistent after excluding patients receiving anticoagulant therapy. The top 25th percentile of Lp(a) level (≥40 mg/dL) combined with the top 25th percentile of hs-CRP level (≥3.5 mg/L) conferred a 4.74-fold risk of HALT.

Does More Invasive Surgery Result in Higher Patient Satisfaction? A Long-Term Follow-Up of 136 Zygomaticomaxillary Complex Fractures.

Retrospective with follow-up. To evaluate the long-term satisfaction of surgically treated patients with zygomaticomaxillary complex (ZMC) fractures in relation to the use of internal fixation, number of fixation points, and orbital floor (OF) reconstruction. Secondary objectives were to describe the use of antibiotics and post-operative infections. Patients with unilateral ZMC fractures between 2007-2018 and treatment with either open reduction and internal fixation (ORIF) or closed reduction (CR) were identified from medical records and invited to follow-ups between 2018-2020. Patients were examined, photographed, and completed a questionnaire. A review panel of 3 experienced surgeons evaluated photographs and computed tomography (CT) scans pre- and post-surgery. The study sample consisted of 136 patients (108 ORIF, 28 CR) with a median follow-up time of 76 months. Patient satisfaction of surgical outcome was high (97.8%), with no significant differences in relation to the use of internal fixation, number of fixation points, or OF reconstruction. Dissatisfaction was primarily related to hypoesthesia. On post-operative CT scans, malar asymmetry was more often predicted in patients with 1-point fixations. On questionnaires and photographs, malar asymmetry was more common in patients with 3-point fixations. Prophylactic antibiotics had no effect on the rate of post-operative infections. Patient satisfaction was not influenced by internal fixation, number of fixation points, or OF reconstruction. Selected ZMC fractures can be treated with less invasive approaches. Caution should be observed when predicting long-term malar asymmetry on post-operative CT scans. The findings of this study highlight the importance of a rational and ethical use of surgery.

Intranasal Outer Cortex Splinting With a Kirschner Wire to Immobilize Reduced Buckle-out Segments in Nasal Fractures.

High-velocity lateral impacts to the nose sometimes cause nasal buckle-out fractures with a trapdoor buckle-out segment displaced outwards. Prolonged immobilization of a reduced buckle-out segment at risk for outward redisplacement remains challenging. Here we introduce a novel method of intranasal outer cortex splinting with a Kirshner (K)-wire to reinforce the reduced state and prevent outward re-displacement of the buckle-out segment. Eighteen patients with nasal buckle-out fractures underwent outer cortex K-wire splinting to securely immobilize a reduced but unstable buckle-out segment after indirect open reduction through intercartilaginous incisions and inner cortex K-wire splinting. A thin K-wire (diameter 0.8mm) was inserted at the vestibule, passed above the upper lateral cartilage and the outer cortex of the reduced buckle-out segment, and extended to the cephalic non-fractured bone. The wire served as a crossbeam, effectively supporting the reduced buckle-out segment. All K-wires for inner and outer cortex splinting were removed 10 to 14 days postoperatively. Immediate postoperative computed tomography scans showed successful immobilization of buckle-out segments in 17 patients (94.5%). Postoperative 6-month scans of 7 patients showed excellent maintenance and bony alignment of buckle-out segments in all cases. Sixteen patients (88.9%) were satisfied with the overall external nasal contour at the last follow-up. There were no complications directly related to outer cortex K-wire splinting. One patient complained of a focal lateral protrusion resulting from the under-correction of a buckle-out segment. This technique may be a valuable option for immobilizing and maintaining reduced nasal buckle-out segments until a stable bony union is established.

Delayed Maxillary Reconstruction with Free Osteocutaneous Fibula Flap Using CAD-CAM Technology

Abstract Background Maxillary reconstruction poses unique challenges for the reconstructive surgeon because of the complex three-dimensional (3D) anatomy of the maxilla. Undertaking this endeavor on secondary reconstruction makes it more difficult due to problems in recreating the true defect. This study is an attempt to demonstrate the role of virtual surgical planning (VSP), 3D printing, and mock surgery in reconstructing such defects using free fibula flaps. Materials and Methods This was a prospective study involving 10 patients of maxillary defects who underwent delayed reconstruction with a free fibula flap. The planning was done preoperatively using computer-aided design and computer-aided manufacturing (CAD-CAM) technology. A mock surgery with 3D printed models was done before the surgery. After the surgery, the accuracy results were obtained by overlapping and measuring fixed point distances between preoperative virtual planning and postoperative computed tomography (CT) scan data. Results and Discussion Nine patients underwent successful reconstruction and were satisfied with the outcome. One patient had flap loss. The mean shift along the horizontal, vertical, and 3D axes was less than 5 mm between the preoperative virtual planning and postoperative CT scan data, indicating accurate reconstruction. We also suggest strategies for soft-tissue and bony inset including inferolateral pedicle origin, anteriorly facing lateral fibular surface, and two bony struts for the alveolus. Conclusion VSP and CAD-CAM technology in maxillary reconstructions help achieve an anatomically accurate neo-maxilla. The addition of mock surgery to the routine and the use of cutting guide avoid unpredictability and reduce the need for adaptation activities on the operating table. CAD-CAM technology despite its limitations is invaluable in maxillary reconstruction and is an important tool for a reconstructive plastic surgeon.