The machine-vision image guided surgery system reduces fluoroscopy time, ionizing radiation and intraoperative blood loss in posterior spinal fusion for scoliosis.

PURPOSE: To determine if the novel 3D Machine-Vision Image Guided Surgery (MvIGS) (FLASH™) system can reduce intraoperative radiation exposure, while improving surgical outcomes when compared to 2D fluoroscopic navigation. METHODS: Clinical and radiographic records of 128 patients (≤ 18 years of age) who underwent posterior spinal fusion (PSF), utilising either MvIGS or 2D fluoroscopy, for severe idiopathic scoliosis were retrospectively reviewed. Operative time was analysed using the cumulative sum (CUSUM) method to evaluate the learning curve for MvIGS. RESULTS: Between 2017 and 2021, 64 patients underwent PSF using pedicle screws with 2D fluoroscopy and another 64 with the MvIGS. Age, gender, BMI, and scoliosis aetiology were comparable between the two groups. The CUSUM method estimated that the MvIGS learning curve with respect to operative time was 9 cases. This curve consisted of 2 phases: Phase 1 comprises the first 9 cases and Phase 2 the remaining 55 cases. Compared to 2D fluoroscopy, MvIGS reduced intraoperative fluoroscopy time, radiation exposure, estimated blood loss and length of stay by 53%, 62% 44%, and 21% respectively. Scoliosis curve correction was 4% higher in the MvIGS group, without any increase in operative time. CONCLUSION: MvIGS for screw insertion in PSF contributed to a significant reduction in intraoperative radiation exposure and fluoroscopy time, as well as blood loss and length of stay. The real-time feedback and ability to visualize the pedicle in 3D with MvIGS enabled greater curve correction without increasing the operative time.

Risk of developing seizure after percutaneous endoscopic lumbar discectomy.

STUDY DESIGN: A retrospective analysis in patients who underwent percutaneous endoscopic lumbar discectomy (PELD) and developed seizures during the procedure; and to identify the risk of developing seizure during PELD by measuring cervical epidural pressure. OBJECTIVE: To evaluate clinical significance, characteristics, and risk factors for developing seizure and neck pain in patients undergoing PELD. SUMMARY AND BACKGROUND DATA: Increased epidural pressure during PELD has been reported earlier. Risk of developing intraoperative seizure has not been investigated till date. We experienced some unexpected complication such as, seizures during PELD, and, therefore, we correlated it with the prodromal symptom and the strategies to avoid such complications during PELD. METHODS: Four of the total 16,725 patients who underwent PELD between 2000 and 2008 developed intraoperative seizures. A review of their medical records and radiologic files were correlated with the complication. Factors evaluated were the type of seizures, prodromal symptoms, comorbidities and clinical outcome. To postulate a pathophysiologic cause of seizure, we designed a study to monitor the intraoperative cervical epidural pressure in 33 patients undergoing PELD. RESULTS: A striking feature of the 4 patients in this series was that they all complained of neck pain before the seizure event. There was no identifiable pattern of seizure observed. The duration of the procedure in these patients was longer than uninvolved cases. None of the patients developed any type of sequel subsequent to seizure. The outcome of surgery has been similar with the patients that did not have any type of complications after PELD. In the subsequent study of cervical epidural pressure, no patients developed seizure. However, there was occurrence of neck pain in the group with increased cervical epidural pressure. CONCLUSIONS: Although rare (0.02%), seizure can occur in patients undergoing PELD, occurrence of neck pain is correlated with increase in cervical epidural pressure, which should be considered as prodromal sign and alert the surgeon. Duration of procedure and speed of infusion are associated risk factor.

Case of sodium-glucose cotransporter-2 inhibitor-associated euglycaemic diabetic ketoacidosis.

Following non-elective orthopaedic surgery, a 61-year-old man with poorly controlled type 2 diabetes mellitus on empagliflozin developed high anion gap metabolic acidosis in the high-dependency unit. Metabolic acidosis persisted despite intravenous sodium bicarbonate, contributing to tachycardia and a run of non-sustained ventricular tachycardia. He was euglycaemic throughout hospital admission. Investigations revealed elevated urine and capillary ketones, and a diagnosis of sodium-glucose cotransporter-2 inhibitor-associated euglycaemic diabetic ketoacidosis was made. He was treated with an intravenous sliding scale insulin infusion and concurrent dextrose 5% with potassium chloride. Within 24 hours of treatment, his arterial pH, anion gap and serum bicarbonate levels normalised. After a further 12 hours, the intravenous insulin infusion was converted to a basal/bolus regimen of subcutaneous insulin, and he was transferred to the general ward. He was discharged well on subcutaneous insulin 6 days postoperatively.

Magnetically Controlled Growing Rods: Influence on Intraoperative Fluoroscopic Imaging: A Case Report.

CASE: A 7-year-old boy with severe congenital scoliosis and impending thoracic insufficiency syndrome underwent uneventful single magnetically controlled growing rod (MCGR) insertion and removal of his ipsilateral rib-based distraction implants at our institution. Intraoperative fluoroscopy imaging revealed an artifactual bend (S-distortion) of the rod actuator after placement. This artifact was eliminated by moving the image intensifier further from the patient. CONCLUSION: We attributed the S-distortion to influences of magnetic fields within the MCGR actuator onto the image intensifier. Surgeons should be aware of such implications which can lead to misleading imaging artifacts. This is a first reported case of such incident with MCGR.

Adjacent segment disease after interbody fusion and pedicle screw fixations for isolated L4-L5 spondylolisthesis: a minimum five-year follow-up.

STUDY DESIGN: A retrospective study. OBJECTIVE: The purpose of this study are (1) to analyze prevalence of clinical and radiologic adjacent segment diseases (ASD), (2) to find precipitating factor of clinical ASD in each isthmic and degenerative spondylolisthesis groups, and (3) to compare clinical and radiologic change in isthmic and degenerative spondylolisthesis. SUMMARY OF BACKGROUND DATA: There is no clinical report regarding the use of magnetic resonance imaging (MRI) for evaluating ASD in patient who underwent 360° fusion with single-level spondylolisthesis with healthy adjacent segment. METHODS: A total of 69 patients who underwent instrumented single-level interbody fusion at the L4-L5 level and showed no definitive degenerated disc in adjacent segments on preoperative MRI and plain radiographs were evaluated at more than 5 years after surgery. The patients were divided into 2 groups: group I was isthmic spondylolisthesis patients and group II was degenerative spondylolisthesis patients. The radiologic ASD was diagnosed by plain radiographs and MRI. Clinical ASD is defined as symptomatic spinal stenosis, intractable back pain, and subsequent sagittal or coronal imbalance with accompanying radiographic changes. Symptomatic spinal stenosis was defined as stenosis diagnosed by MRI and combined with neurologic claudication. RESULTS: The prevalence of radiologic ASD on group I and group II was 72.7% and 84.0%, respectively. About 7 (15.9%) patients showed clinical ASD in group I and 6 (24.0%) patients showed clinical ASD in group II. MRI showed significant reliability for diagnosis of clinical ASD. Compared with patients with asymptomatic ASD, patients with clinical ASD showed significantly less postoperative lordotic angle at the L4-L5 level (i.e., less than 20°) in both groups. CONCLUSION: Maintaining postoperative L4-L5 segmental lordotic angle at about 20° or more is important for prevention of clinical ASD in single-level 360° fusion operation. MRI is reliable method for diagnosing clinical ASD.

The relationship of the lateral cord of the brachial plexus to the coracoid process during arthroscopic coracoid surgery: a dynamic cadaveric study.

BACKGROUND: Arthroscopic coracoid decompression is performed for coracoid impingement and has also been advocated for arthroscopic repair of tears of the subscapularis tendon, placing the lateral cord or the musculocutaneous nerve at risk of injury. The dynamic relationship of the lateral cord to the coracoid while the upper limb is in abduction and traction in the shoulder arthroscopy position is not clear. PURPOSE: The purpose of this study was to evaluate the dynamic relationship of the lateral cord of the brachial plexus to the coracoid process during varying degrees of upper limb abduction in traction. STUDY DESIGN: Descriptive laboratory study. METHODS AND MATERIALS: The musculocutaneous nerves of 15 fresh-frozen cadaveric shoulders were carefully dissected and identified without mobilization of the nerve. The musculocutaneous nerve was then injected with radiopaque contrast mixed with methylene blue. The contrast would infiltrate retrogradely into the lateral cord, minimizing mobilization of the lateral cord. The specimens were mounted in the lateral decubitus position with 4.5 kg of traction to the forearm and anteroposterior radiographs were taken at 30 degrees and 60 degrees of abduction. The nearest distance of the lateral cord to the coracoid process was measured off the radiographs and the displacement with increase in shoulder abduction was determined. RESULTS: The mean nearest distance between the lateral cord and the coracoid tip at 30 degrees of shoulder abduction was 26.6 +/- 5.2 mm and it moved nearer at 60 degrees of abduction to 23.4 +/- 5.1 mm; the difference of 3.2 mm was statistically significant (P < .0005, 95% confidence interval, 2.5-3.9 mm). The shortest distance measured was 14.4 mm in 1 specimen at 60 degrees of abduction. CONCLUSION: The lateral cord moved closer to the coracoid process at 60 degrees than at 30 degrees of abduction under traction during simulated shoulder arthroscopy position using the lateral decubitus position. CLINICAL RELEVANCE: The margin of safety for lateral cord injury during arthroscopic surgery around the coracoid process is improved with lower abduction angles in the lateral decubitus position.