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Introduction: Penetrating spinal cord injuries present unique clinical scenarios with high variability in presentation and management. These injuries are rare, accounting for 0.8% of annual penetrating spine injuries in the United States, with knives being the most common penetrating object. Retention of the knife blade further complicates management, with greater risk of infection and progressive neurologic injury. Given the rarity and variability of such injuries, preferred management for penetrating-knife spinal cord injuries (PKSCI), especially those with retained knife blades, remains contested. Furthermore, the management of PKSCI with concurrent lung injury is poorly described within the literature. Case Report: Here we discuss a unique case of a neurologically intact adult male who suffered a large lower thoracic PKSCI with complete dural transection and lung involvement. The patient arrived with the blade in situ while maintaining full neurologic function. Emergent imaging revealed the blade trajectory passing through the T8 lamina exiting the spinal canal at the costovertebral junction with involvement of the lung parenchyma and associated pneumorrhachis and pneumothorax. The patient was brought to the operating room where the blade was removed under direct visualization, the dura was repaired, and pneumothorax was stabilized. Conclusion: We describe in this case the choice of imaging, method of blade removal, cerebrospinal fluid leak management, dural repair, and concurrent lung injury management that afforded a favorable, ASIA class E outcome with complete preservation of neurologic function. [ABSTRACT FROM AUTHOR]

Primary leiomyosarcoma of the inferior vena cava (IVC) is a rare and aggressive mesenchymal tumor, with less than 400 reported cases to date. Complete resection of the tumor with clear margins is the only proven curative treatment, providing survival benefits. Nonetheless, leiomyosarcomas in the middle segment or those extending up to it within the inferior vena cava (IVC) frequently necessitate renal reimplantation or nephrectomy, with rates varying between 56% and 75%. In this case report, we present a 65-year-old female with lower segment IVC leiomyosarcoma with middle segment extension, successfully resected and reconstructed while avoiding associated renal reimplantation or nephrectomy morbidity. [ABSTRACT FROM AUTHOR]

Study Design: Systematic review. Objectives: Intraoperative neuromonitoring (IOMN) has become a standard practice in the detection and prevention of nerve damage and postoperative deficit. While multicenter studies have addressed this inquiry, there have been no systematic reviews to date. This systematic review identifies the leading causes of IONM alerts during adult spinal deformity (ASD) surgeries. Methods: Following PRISMA guidelines, a literature search was performed in PubMed and Embase. IONM alert causes were grouped by equivalent terms used across different studies and binned into larger categories, including surgical maneuver, Changes in blood pressure/temperature, Oxygenation, Anesthesia, Patient position, and Unknown. Results: Inclusion criteria were studies on adult patients receiving ASD correction surgery using IONM with documented alert causes. 1544 references were included in abstract review, 128 in full text review, and 16 studies qualified for data extraction. From those studies, there was a total of 3945 adult patients with 299 IONM alerts. Surgical maneuver led the alert causes (258 alerts/86.3%), with signal loss most commonly occurring at correction or osteotomy (101/33.8% and 95/31.8% respectively). Pedicle screw placement caused 35 alerts (11.7%). Changes in temperature and blood pressure were the third largest category (34/11.4%). Conclusions: The most frequent causes of IONM alerts in ASD surgery were surgical maneuvers such as correction, osteotomy, and pedicle screw placement. This information provides spine surgeons with a quantitative perspective on the causes of IONM changes and show that most occur at predictable times during ASD surgery. [ABSTRACT FROM AUTHOR]

Objectives: Intraoperative parathyroid hormone (IOPTH) monitoring has become routine in parathyroid surgery to facilitate less invasive techniques to treat hyperparathyroidism. Despite this, little is known about in vivo IOPTH kinetics, which can greatly affect the reliability of its interpretation. Methods: A prospective cohort of patients undergoing routine parathyroidectomy was studied. During each case, IOPTH was measured frequently, during all key perioperative events. Qualitative, univariate, and multivariate analysis was performed to better understand the patterns of in vivo IOPTH kinetics. Results: The IOPTH increased from preoperative baseline in every case, but some patients had a rapid spike after gland manipulation while others had a more gradual increase. The IOPTH peak occurred prior to excision in almost every case. The IOPTH began to fall prior to excision, typically returning to preoperative baseline levels just before excision. The average in vivo half-life of parathyroid hormone (PTH) was 5.2 minutes. Conclusion: There is substantial variation in the in vivo IOPTH kinetics and more research is needed to understand predictors of kinetic patterns and PTH half-life during parathyroidectomy. [ABSTRACT FROM AUTHOR]

Background: Bronchial stenosis associated with bronchial anastomosis dehiscence after lung transplantation is a catastrophic complication following lung transplantation with a paucity of therapeutic solutions. Purpose: To describe an adaptation of the parallel stent grafting technique in the pulmonary arterial territory to treat this challenging situation. Research Design: This is a case report of a 52-year-old patient who presented bronchus stenosis and bronchial anastomosis dehiscence after lung transplantion. Bronchial stenting and lung retransplantation were contraindicated. Therefore, an endovascular approach using pulmonary artery endograft placement to prevent bleeding during repeated right bronchial balloon dilation was propposed. The technique consists of the deployment of an aortic extender endoprosthesis in the right main pulmonary artery and a balloon expandable stent in the upper lobe pulmonary artery (using a parallel graft configuration) through the common femoral and right internal jugular veins, respectively. Intraoperative transesophageal echocardiogram and one-lung ventilatory ventilation are needed. Results: The patient underwent a new bronchoscopy 16 days after the procedure, that showed epithelization at the previous eroded zone, enabling bronchocopic balloon dialtion to be safely performed. A post-operative contrast-enhanced CT scan revealed an adequate positioning of the stent grafts. Despite all eforts, the patient succumbed to ventilator associated pneumonia on postoperative day 108. Data Analysis: The technique's advantages include its feasibility even in situations in which other techniques may be contraindicated and its potential use in emergencies. Its limitations include the need for experienced interventionists to perform it, and the potential risk of acute tricuspid regurgitation. Conclusion: This study illustrates the early feasibility of the parallel stent grafting technique applied to the pulmonary artery territory. However, it's safety profile regarding infectious risk was not demontrated. [ABSTRACT FROM AUTHOR]

Background: The addition of epinephrine to arthroscopic irrigation fluid has been shown to improve surgeon-rated visual clarity during shoulder arthroscopic surgery. Subacromial injections of epinephrine are also used for this purpose. Purpose/Hypothesis: To assess the influence of a preoperative subacromial epinephrine injection on surgeon visualization during subacromial shoulder arthroscopic surgery. It was hypothesized that the epinephrine injection would improve surgeon-rated visual clarity. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: A double-blind randomized controlled trial including adult patients undergoing shoulder arthroscopic surgery in the beach-chair position requiring visualization of the subacromial space was performed. Patients in the epinephrine group (n = 30) received a preoperative subacromial injection of bupivacaine and epinephrine, and those in the control group (n = 30) received a preoperative subacromial injection of bupivacaine. Epinephrine was added to the first 10 L of arthroscopic irrigation fluid in all patients. The primary outcome was surgeon-rated visual clarity throughout the procedure that was recorded at the end of the procedure using a visual analog scale (VAS) scored from 0 (worst) to 10 (best). Secondary outcomes included an increase in pump pressure during the procedure, total operative time, and the intraoperative use of blood pressure–modulating medications. Results: Rotator cuff repair was performed in 88.3% of patients (25/30 epinephrine; 28/30 control), with multiple procedures performed in 85.0% of patients (23/30 epinephrine; 27/30 control). The VAS score for visual clarity was slightly better in the epinephrine group compared with the control group, although the difference was neither statistically nor clinically significant (8.3 ± 1.4 vs 7.5 ± 1.8, respectively; P =.09). There was no difference between the epinephrine and control groups in the need for an increase in pump pressure to improve visualization (8/30 [26.7%] vs 7/30 [23.3%], respectively; P >.99), total operative time (62.0 ± 19.4 vs 64.0 ± 30.1 minutes, respectively; P =.90), or the intraoperative use of blood pressure–modulating medications (20/30 [66.7%] vs 17/30 [56.7%], respectively; P =.60). There were no perioperative adverse events in either group. Conclusion: The addition of a subacromial epinephrine injection before shoulder arthroscopic surgery resulted in a small improvement in visual clarity that was neither statistically nor clinically significant, with no adverse effects reported in this study. Registration: NCT05244525 (ClinicalTrials.gov) [ABSTRACT FROM AUTHOR]

Study Design: Systematic literature review and meta-analysis. Objectives: Predicting patient risk of intraoperative neuromonitoring (IONM) alerts preoperatively can aid patient counselling and surgical planning. Sielatycki et al established an axial-MRI-based spinal cord classification system to predict risk of IONM alerts in scoliosis correction surgery. We aim to systematically review the literature on operative and radiologic factors associated with IONM alerts, including a novel spinal cord classification. Methods: A systematic review and meta-analysis was performed as per the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) Guidelines. A literature search identifying all observational studies comparing patients with and without IONM alerts was conducted. Suitable studies were included. Patient demographics, radiological measures and operative factors were collected. Results: 11 studies were included including 3040 patients. Relative to type 3 cords, type 1 (OR =.03, CI =.01-.08, P <.00001), type 2 (OR =.08, CI =.03, P <.00001) and all non-type 3 cords (OR =.05, CI =.02-.16, P <.00001) were associated with significantly lower odds of IONM alerts. Significant radiographic measures for IONM alerts included coronal Cobb angle (MD = 10.66, CI = 5.77-15.56, P <.00001), sagittal Cobb angle (MD = 9.27, CI = 3.28-14.73, P =.0009), sagittal deformity angle ratio (SDAR) (MD = 2.76, CI = 1.57-3.96, P <.00001) and total deformity angle ratio (TDAR) (MD = 3.44, CI = 2.27-4.462, P <.00001). Clinically, estimated blood loss (MD = 274.13, CI = −240.03-788.28, P =.30), operation duration (MD = 50.79, CI = 20.58-81.00, P =.0010), number of levels fused (MD =.92, CI =.43-1.41, P =.0002) and number of vertebral levels resected (MD =.43, CI =.01-.84, P =.05) were significantly greater in IONM alert patients. Conclusions: This study highlights the relationship of operative and radiologic factors with IONM alerts. [ABSTRACT FROM AUTHOR]

Background: The aim of this study is to describe the management and associated follow-up strategies adopted by thyroid surgeons with different surgical volumes when loss of signal (LOS) occurred on the first side of planned bilateral thyroid surgery, and to further define the consensus on intraoperative neuromonitoring (IONM) applications. Methods: The International Neural Monitoring Study Group (INMSG) web-based survey was sent to 950 thyroid surgeons worldwide. The survey included information on the participants, IONM team/equipment/procedure, intraoperative/postoperative management of LOS, and management of LOS on the first side of thyroidectomy for benign and malignant disease. Results: Out of 950, 318 (33.5%) respondents completed the survey. Subgroup analyses were performed based on thyroid surgery volume: <50 cases/year (n = 108, 34%); 50 to 100 cases/year (n = 69, 22%); and >100 cases/year (n = 141, 44.3%). High-volume surgeons were significantly (P <.05) more likely to perform the standard procedures (L1-V1-R1-S1-S2-R2-V2-L2), to differentiate true/false LOS, and to verify the LOS lesion/injury type. When LOS occurs, most surgeons arrange otolaryngologists or speech consultation. When first-side LOS occurs, not all respondents decided to perform stage contralateral surgery, especially for malignant patients with severe disease (eg, extrathyroid invasion and poorly differentiated thyroid cancer). Conclusions: Respondents felt that IONM was optimized when conducted under a collaborative team-based approach, and completed IONM standard procedures and management algorithm for LOS, especially those with high volume. In cases of first-site LOS, surgeons can determine the optimal management of disease-related, patient-related, and surgical factors. Surgeons need additional education on LOS management standards and guidelines to master their decision-making process involving the application of IONM. [ABSTRACT FROM AUTHOR]

Objectives: Previous studies in shoulder and knee arthroscopy have reported that tranexamic acid (TXA) may improve early functional recovery, prevent postoperative intra-articular bleeding, reduce subjective pain, and improve intra-operative visual field clarity. However, there is a paucity of literature describing the use of TXA in hip arthroscopy. Previous studies have reported statistically significant improvements in VAS pain and Modified Hip Harris scores. However, they used a limited subset of Patient Reported Outcome Measures (PROMs) and did not characterize the effects of TXA on visibility during arthroscopy. The primary objective of this study is to determine the role of TXA in hip arthroscopy based on assessment of postoperative pain and function. A second objective of this study is to determine whether TXA influences intra-operative visual clarity and pump pressures. Methods: This double blinded randomized controlled trial is enrolling 70 patients undergoing primary hip arthroscopy. Subjects are randomized to receive TXA (n=35) or not receive TXA (n=35). The TXA group receives 1g of TXA intravenously at the time of incision and another 1g of TXA during closure. For the duration of the surgery, arthroscopic visual field clarity is rated by the surgeon every 15 minutes as poor, fair, or good and assigned a score of 1, 2, and 3, respectively. Each time the visual clarity is rated, pump pressure is also recorded. Range of motion, VAS Pain, iHOT-12, HOS Sport and activities of daily living, PROMIS Physical Function (PF), and PROMIS Pain Interference (PI) scores are collected preoperatively and postoperatively at days 14 and 42. Additionally, VAS pain is assessed at postoperative day 1. At the completion of all study activities, patient charts are reviewed to determine whether they have requested any additional analgesic medication during the study. Results: The preliminary data for this study includes completed data from 16 (9 female, 7male) patients with a mean age of 44 years. The TXA and control groups had 9 and 7 patients, respectively. No significant difference in VAS pain scores were observed preoperatively, at 1 day postoperatively, or at 42 days postoperatively. There was a significant difference (p=0.01) in VAS pain scores between the two groups at 14 days postoperatively, with the TXA and control groups having mean scores of 2.22 ± 1.48 and 4.33 ± 1.21, respectively. Both groups have shown improvements in PROMs between preoperative scores and postoperative day 42, with larger improvements being seen in the TXA group (although failing to meet statistical significance). Complete preliminary data for PROMs can be seen in Table 1. The average visual score in the TXA group (2.85 ± 0.25) was better than that of the control group (2.67 ± 0.2) but failed to meet statistical significance (p=0.132). The frequency that each rating was assigned was calculated for each group and can be seen in Table 2. A chi-squared test of independence was conducted to examine the relationship between the distribution of grades (Good, Fair, Poor) and the treatment groups (TXA and Control). The test indicated no association between the two variables (Pearson's χ² = 5.6, df = 2, p = 0.06). Although the p-value did not reach significance level (α<0.05), the preliminary data favored the TXA group in terms of visibility. Pump pressures did not show any significant difference between the TXA group and the control group at any of the time points. No patients have requested additional pain medications during their involvement in this study at this time. Conclusions: The use of TXA in hip arthroscopy descriptively demonstrated improvements in post-operative pain and function, but not intraoperative visual clarity. The trends in the preliminary data, particularly for visual clarity and the measures of pain such as VAS Pain (Figure 1) and PROMIS-PI (Figure 2), suggest a clinical benefit to intraoperative TXA use. Larger sample sizes are needed to establish the significance of these findings and further explore the relationship between TXA and postoperative outcomes, visual clarity, and pump pressures in hip arthroscopy. [ABSTRACT FROM AUTHOR]

Background: There is a lack of data regarding the long-term clinical outcomes of open repair of humeral avulsion of the glenohumeral ligament (HAGL). Purpose: To examine the long-term patient outcomes, prevalence of related shoulder lesions, and return to sports in patients who have had open HAGL repair. Study Design: Case series; Level of evidence, 4. Methods: Included were 47 patients who underwent open repair of an HAGL lesion between 1995 and 2013. Clinical results were assessed using the Western Ontario Shoulder Instability Index (WOSI). Recurrence of instability, additional surgeries, confidence in the shoulder, level and type of sport before and after surgery, and return to sports were documented. Results: The mean follow-up duration was 105 months (range, 16-247 months). The mean postoperative WOSI score was 410. Postoperatively, 10 patients experienced a recurrence of instability. Subgroup analysis of patients who reported recurrence demonstrated significantly worse WOSI scores compared with patients who did not experience recurrence (730 [95% CI, 470-990] vs 320 [95% CI, 210-430], respectively; P =.007). Before surgery, 33 patients participated in competitive sports, compared with 22 patients after surgery. No postoperative neurologic or vascular complications were recorded. In 51% of patients, a labral tear was noted as a concomitant injury. Conclusion: Open repair of an HAGL lesion restored shoulder stability with good results. However, recurrence was significant (21%) with longer follow-up, and return to sports was affected. Associated lesions were prevalent. [ABSTRACT FROM AUTHOR]

To preserve residual hearing during cochlear implant (CI) surgery it is desirable to use intraoperative monitoring of inner ear function (cochlear monitoring). A promising method is electrocochleography (ECochG). Within this project the relations between intracochlear ECochG recordings, position of the recording contact in the cochlea with respect to anatomy and frequency and preservation of residual hearing were investigated. The aim was to better understand the changes in ECochG signals and whether these are due to the electrode position in the cochlea or to trauma generated during insertion. During and after insertion of hearing preservation electrodes, intraoperative ECochG recordings were performed using the CI electrode (MED-EL). During insertion, the recordings were performed at discrete insertion steps on electrode contact 1. After insertion as well as postoperatively the recordings were performed at different electrode contacts. The electrode location in the cochlea during insertion was estimated by mathematical models using preoperative clinical imaging, the postoperative location was measured using postoperative clinical imaging. The recordings were analyzed from six adult CI recipients. In the four patients with good residual hearing in the low frequencies the signal amplitude rose with largest amplitudes being recorded closest to the generators of the stimulation frequency, while in both cases with severe pantonal hearing losses the amplitude initially rose and then dropped. This might be due to various reasons as discussed in the following. Our results indicate that this approach can provide valuable information for the interpretation of intracochlearly recorded ECochG signals. [ABSTRACT FROM AUTHOR]

Study Design: Retrospective cohort study. Objectives: Intraoperative neurophysiological monitoring (IONM) is widely used in spinal neurosurgery, particularly for intramedullary tumours. However, its validity in intradural extramedullary (IDEM) spinal tumours is less clearly defined, this being the focus of this study. Methods: We compared outcomes for patients that underwent resection of IDEM tumours with and without IONM between 2010 and 2020. Primary outcomes were postoperative American Spinal Injury Association (ASIA) scores. Other factors assessed were use of intraoperative ultrasound, drain placement, postoperative complications, postoperative Eastern Cooperative Oncology Group (ECOG) score, extent of resection, length of hospital stay, discharge location and recurrence. Results: 163 patients were included, 71 patients in the IONM group and 92 in the non-IONM group. No significant differences were noted in baseline demographics. For preoperative ASIA D patients, 44.0% remained ASIA D and 49.9% improved to ASIA E in the IONM group, compared to 39.7% and 30.2% respectively in the non-IONM group. For preoperative ASIA E patients, 50.3% remained ASIA E and 44.0% deteriorated to ASIA D in the IONM group, compared to 30.2% and 39.7% respectively in the non-IONM group (all other patients deteriorated further). Length of inpatient stay was significantly shorter in the IONM group (P =.043). There were no significant differences in extent of resection, postoperative complications, discharge location or tumour recurrence. Conclusions: Research focusing on the use of IONM in IDEM tumour surgery remains scarce. Our study supports the use of IONM during surgical excision of IDEM tumours. [ABSTRACT FROM AUTHOR]

Head and neck positioning is a key element of craniofacial reconstructive surgery and can become challenging when intervention necessitates broad exposure of the calvarium. We present a case of craniosynostosis secondary to Apert's syndrome requiring anterior and posterior cranial vault access during surgical correction. A modified sphinx position was used that required significant neck extension. The patient had concurrent Chiari I malformation with brain stem compression so intraoperative neuromonitoring (IONM) was used to ensure that there were no negative effects on the neural elements with positioning. This highlights benefits of IONM in a setting not typically associated with its use. [ABSTRACT FROM AUTHOR]

Study Design: Prospective observational cohort. Objectives: To examine the cost-effectiveness of IntraOperative ElectroMyeloGraphy (IO-EMG) by evaluating how often an abnormal IO-EMG signal changed the surgeon's surgical plan, or replaced a pedicle screw either intra-operatively or as a second unplanned surgery. Methods: Patients undergoing instrumented posterolateral lumbar fusion were monitored with intraoperative triggered EMG's. Pedicle screws were placed freehand from L1 to S1 by attending physicians and fellows. Concern for pedicle breach was a screw stimulation<10 mA. Results: There were 145 cases with a total of 725 pedicle screws placed. Mean age was 57.8 ± 14.2 yrs, OR time was 238 ± 95 minutes, EBL was 426.8 ± 354.3cc. Mean number of surgical levels fused was 2.7 ± 1.1. 686 (95%) screws stimulated at >10 mA and 39 (5%) screws stimulated at <10 mA. All 39 screws were removed and pedicles re-examined. Intraoperative screw repositioning was necessary in 8 of 145 cases (6%). No patient required a return to the OR for screw repositioning. As a worst case cost analysis, assuming the 8 patients requiring intraoperative screw positioning would have returned to the OR at a cost of $11,798 per readmission, the per patient cost is $651 which is less than the ION per patient cost of $750. Conclusions: Only 1% of the 725 lumbar pedicle screws placed in 8 of 145 cases required repositioning. Due to the infrequency of pedicle wall breaches and the cost of ION, the utility of this modality in straightforward lumbar fusions should be critically evaluated. [ABSTRACT FROM AUTHOR]

Study design: Retrospective cohort study Objectives: Vasoplegia is a life-threatening form of distributive or vasodilatory shock that is characterized by reduced systemic vascular resistance with resultant hypotension and normal to elevated cardiac output affecting morbidity and mortality. Vasoplegia in the context of Spine Surgery has not been described previously. The purpose of this case series is to determine incidence, risk factors, complications and postoperative outcome in patients with vasoplegia after complex multi-level thoraco-lumbar spine surgery. Methods: A retrospective review of the electronic medical records at our institution was conducted between January 2014 and June 2018. All patients undergoing multi-level spine surgery (>6 levels) were screened for intraoperative hypotension. Patient demographics, surgical characteristics, neurological status, blood loss, risk factors, medical treatment, complications, hospital course and mortality were collected. All patients included in this study had a minimum follow-up period of 3 months. Results: Out of 8521 surgically treated patients, 994 patients with multi-level thoraco-lumbar spine surgery were identified. A total of 41 patients had intraoperative hypotensive events. Of those, 5 patients with vasoplegia could be identified after elimination of all other potential contributing factors. Vasoplegia did not influence the neurological outcome. One major and three minor complications occurred. All patients showed full recovery. The risk factors identified for vasoplegia include prolonged surgery with osteotomies. Conclusions: Vasoplegia is a rare condition with an incidence of.6%. Patients experiencing vasoplegia did not appear to experience worse surgical outcomes. The use of special intraoperative hemodynamic monitoring should be considered in selected cases. [ABSTRACT FROM AUTHOR]

Objectives: To compare subjective voice outcomes and postoperative laryngoscopic examination findings of patients with subjective voice complaints between surgeon-monitored and certified technician–monitored thyroidectomies. Methods: Patients who underwent hemithyroidectomy, total thyroidectomy, and completion thyroidectomy using a nerve monitoring system between November 2015 and June 2018 were included in the study. Retrospective chart review was carried out to assess how often patients reported voice changes and to record postoperative flexible laryngoscopic findings of patients when that examination was performed. Data were analyzed using the χ2 test to identify significant differences in outcomes for the 2 groups. Results: A total of 293 procedures was performed among 3 surgeons. Surgeons monitored the nerves in 147 cases and a certified technician monitored the nerves in 146 cases. Subjective voice changes were identified in 11 (7.48%) cases in the surgeon-monitored group and in 20 (13.70%) cases in the technician-monitored group (P =.084). Among the patients who expressed subjective voice changes, 7 patients were identified with vocal cord hypomobility or immobility in the surgeon-monitored group and 13 patients had an abnormal examination in the technician-monitored group (P =.234). Conclusions: Subjective voice changes or proven vocal cord mobility problems were not different between surgeon-monitored patients and technician-monitored patients in thyroidectomies. [ABSTRACT FROM AUTHOR]

The objective to preserve residual hearing during cochlear implantation has recently led to the use of intracochlear electrocochleography (ECochG) as an intraoperative monitoring tool. Currently, a decrease in the amplitude of the difference between responses to alternating-polarity stimuli (DIF response), predominantly reflecting the hair cell response, is used for providing feedback. Including other ECochG response components, such as phase changes and harmonic distortions, could improve the accuracy of surgical feedback. The objectives of the present study were (1) to compare simultaneously recorded stepwise intracochlear and extracochlear ECochG responses to 500 Hz tone bursts, (2) to explore patterns in features extracted from the intracochlear ECochG recordings relating to hearing preservation or hearing loss, and (3) to design support vector machine (SVM) and random forest (RF) classifiers of acoustic hearing preservation that treat each subject as a sample and use all intracochlear ECochG recordings made during electrode array insertion for classification. Forty subjects undergoing cochlear implant (CI) surgery at the Oslo University Hospital, St. Thomas' Hearing Implant Centre, or the University Hospital of Zurich were prospectively enrolled. In this cohort, DIF response amplitude decreases did not relate to postoperative acoustic hearing preservation. Exploratory analysis of the feature set extracted from the ECochG responses and preoperative audiogram showed that the features were not discriminative between outcome classes. The SVM and RF classifiers that were trained on these features could not distinguish cases with hearing loss and hearing preservation. These findings suggest that hearing loss following CI surgery is not always reflected in intraoperative ECochG recordings. [ABSTRACT FROM AUTHOR]

Significance Statement: Facial nerve schwannoma is extremely uncommon. Despite its rarity, it is considered the most common facial nerve tumor and potentially affects any segment of the nerve. Presenting symptoms vary depending on the location of the neoplasm. Tumors pertaining to the extratemporal course of the nerve mainly appear as an asymptomatic parotid mass. We present a rare case of schwannoma of the zygomatic branch of the right facial nerve that was surgically resected, without facial nerve injury. [ABSTRACT FROM AUTHOR]

Highly accurate real-time cochlear nerve monitoring to preserve cochlear nerve function is essential for simultaneous cochlear implantation and ipsilateral vestibular schwannoma resection. In the present study, we developed a novel real-time monitoring system that combines dorsal cochlear nucleus action potential monitoring with intracochlear stimulating electrodes (Auditory Nerve Test System, ANTS). We used this system for a case with vestibular schwannoma resection via the translabyrinthine approach. The monitoring system developed in this study detected highly reliable evoked potentials from the cochlear nerve every two seconds continuously during tumor resection. Near-total tumor resection was achieved, and cochlear implantation was performed successfully after confirming the preservation of cochlear nerve function in a case. The patient's hearing was well compensated by cochlear implantation after surgery. Our novel method continuously achieved real-time monitoring of the cochlear nerve every two seconds during vestibular schwannoma resection. The usefulness of this monitoring system for simultaneous tumor resection and cochlear implantation was demonstrated in the present case. The system developed in this study is compatible with continuous facial nerve monitoring. This highly accurate and novel monitoring method will broaden the number of candidates for this type of surgery in the future. [ABSTRACT FROM AUTHOR]

Background: Intracapsular resection of head and neck peripheral nerve sheath tumors (PNST) has emerged as a nerve-preserving technique compared to en bloc resection. The aim of this study was to evaluate and compare the functional outcome of both surgical techniques performed at a single tertiary referral center. Methods: This is a retrospective cohort of patients with head and neck PNST undergoing surgical resection from 2011 to 2021 at the Tel Aviv Sourasky Medical Center. Demographic data, the nerve of origin and surgical technique, including the use of intraoperative nerve monitoring were recorded and analyzed in association with postoperative functional outcomes. Results: Overall, 25 patients who had a cervical or parapharyngeal PNST resected were included. Nerve function was preserved in 11 of 18 patients (61%) who underwent intracapsular resection, while all those who underwent en bloc resections inevitably suffered from neurologic deficits (100%, N = 7). Sympathetic chain origin and an apparent neurologic deficit pre-operatively were associated with postoperative neural compromise. Conclusion: Improved functional outcome can be anticipated following intracapsular resection of extracranial head and neck PNST compared to complete resection, particularly in asymptomatic patients. [ABSTRACT FROM AUTHOR]

Background: Malpositioning of the femoral button is a known technical complication after anterior cruciate ligament (ACL) reconstruction with cortical suspensory fixation. The incidence of malpositioning, as well as the efficacy of methods to prevent malpositioning of cortical suspensory fixation devices, has not been reported. Purpose: To determine the rate of malpositioned cortical suspensory fixation devices after ACL reconstruction, investigate which intraoperative technique yields the lowest rate of malpositioning, and determine the return-to-duty rate for active-duty service members with malpositioned buttons and the revision rate for malpositioned buttons. Study Design: Case series; Level of evidence, 4. Methods: The records of patients who underwent primary ACL reconstruction with a cortical suspensory fixation device between 2008 and 2018 were reviewed at our institution. Postoperative radiographs were reviewed for evidence of malpositioned femoral buttons. Malpositioned buttons were classified as (1) fully positioned in the bone tunnel, (2) partially positioned in the bone tunnel, (3) >2 mm from cortical bone, or (4) deployed over the iliotibial band. Operative reports were reviewed to determine the intraoperative methods undertaken to verify the button position. The rate of malpositioned cases with subjective instability and revision surgery performed were determined. The ability of patients to return to full military duty was reviewed for active-duty personnel. Results: A total of 1214 patients met the inclusion criteria. A 3.5% rate (42 cases) of malpositioned cortical suspensory fixation devices (femoral buttons) was identified. For patients with malpositioned buttons, 7 (16.7%) patients underwent revision surgery in the immediate postoperative period. Techniques used to avoid malpositioning included direct arthroscopic visualization, direct open visualization, intraoperative fluoroscopy, and first passing the button through the skin before positioning on the femoral cortex. There was a 4.6% malposition rate using direct arthroscopic visualization and a 5.1% malposition rate using passage of the button through the skin, while no malpositioning occurred with intraoperative fluoroscopy or direct open visualization (P <.05). Overall, 12 (28.6%) patients with malpositioned buttons ultimately underwent revision surgery. Despite having been diagnosed with malpositioned buttons, 21 (63.6%) active-duty members were able to return to full duty. Conclusion: Malpositioning of femoral buttons during ACL reconstruction occurred in 3.5% of patients in this series. The techniques of intraoperative fluoroscopy and direct open visualization are encouraged to prevent malpositioning. [ABSTRACT FROM AUTHOR]

Study Design: Retrospective multicenter cohort study Objectives: We aimed to clarify the efficacy of multimodal intraoperative neuromonitoring (IONM), especially in transcranial electrical stimulation of motor-evoked potentials (TES-MEPs) with spinal cord-evoked potentials after transcranial stimulation of the brain (D-wave) in the detection of reversible spinal cord injury in high-risk spinal surgery. Methods: We reviewed 1310 patients who underwent TES-MEPs during spinal surgery at 14 spine centers. We compared the monitoring results of TES-MEPs with D-wave vs TES-MEPs without D-wave in high-risk spinal surgery. Results: There were 40 cases that used TES-MEPs with D-wave and 1270 cases that used TES-MEPs without D-wave. Before patients were matched, there were significant differences between groups in terms of sex and spinal disease category. Although there was no significant difference in the rescue rate between TES-MEPs with D-wave (2.0%) and TES-MEPs (2.5%), the false-positivity rate was significantly lower (0%) in the TES-MEPs-with-D-wave group. Using a one-to-one propensity score-matched analysis, 40 pairs of patients from the two groups were selected. Baseline characteristics did not significantly differ between the matched groups. In the score-matched analysis, one case (2.5%) in both groups was a case of rescue (P = 1), five (12.5%) cases in the TES-MEPs group were false positives, and there were no false positives in the TES-MEPs-with-D-wave group (P =.02). Conclusions: TES-MEPs with D-wave in high-risk spine surgeries did not affect rescue case rates. However, it helped reduce the false-positivity rate. [ABSTRACT FROM AUTHOR]

Study Design: Retrospective Cohort Study Objective: To evaluate the accuracy of intraoperatively measured computed tomography (CT) Hounsfield unit (HU) values by comparison with preoperative CT HU values and to compare the radiation exposure between preoperative and intraoperative CT scans. Methods: HU values of lumbar vertebrae were measured and compared between preoperative and intraoperative CT scans in patients undergoing lumbar interbody fusion. In patient group one, Canon CT scanners were used preoperatively and the AIRO CT scanner was used intraoperatively. In patient group two, Canon CT scanners were used preoperatively and the O-arm Cone Beam CT (CBCT) scanner was used intraoperatively. In a subgroup analysis of patient group one, radiation by means of CT Dose Index (CTDI) was compared between Canon and AIRO CT scanners. Results: In the first patient group, a total of 250 vertebrae were analysed in 74 patients showing a strong Pearson correlation of >.94 between pre- and intraoperative HU values. Bland-Altman analysis indicated consistency and equivalence with a bias of 3.9 and 95% limits of agreement from −27.17 to 34.97 when comparing all pre- and intraoperative HU values of L1–5. In the second patient group, a total of 27 vertebrae were analysed in 10 patients showing weak Pearson correlation and Bland-Altman analysis indicated no equivalence. CTDI did not differ between Canon and AIRO CT scanners. Conclusion: Correct and reliable CT HU measurement as mandatory key factor for the intraoperative assessment of bone quality and robotic-assisted surgery is feasible with intraoperative AIRO CT imaging without increase of radiation exposure. [ABSTRACT FROM AUTHOR]

Facial nerve schwannomas are rare, benign, slow-growing tumors that can occur in any segment of the facial nerve, although 71% of cases are intratemporal. Surgical resection can lead to facial nerve injury. Facial function recovery after reanimation is usually not better than House-Brackmann (HB) grade III. Thus, for cases of intratemporal facial nerve schwannomas (IFNSs) with favorable facial function (HB grade I or II), observation by periodic magnetic resonance imaging is the mainstay of management. Here, we present a case of a large IFNS with normal facial function in which the mass fully occluded the external auditory canal. The occlusion caused squamous debris to accumulate, potentially leading to cholesteatoma. Faced with this therapeutic dilemma, we chose surgical resection with the patient's informed consent. Stripping surgery was achieved with normal postoperative facial function. There was no postoperative facial paralysis or recurrence at 2-year follow-up. We describe the experience of diagnosis and treatment process for this case, and discuss the possibility of total resection of the tumor with preserving the integrity of facial nerve. [ABSTRACT FROM AUTHOR]

Background: Treatment decisions for cartilage defects are often based on lesion size. Magnetic resonance imaging (MRI) is widely used to diagnose cartilage defects noninvasively; however, their size estimated from MRI may differ from defect sizes measured during arthrotomy, especially after debridement to healthy cartilage if undergoing autologous chondrocyte implantation. Purpose/Hypothesis: The purpose of this study was to evaluate the reliability of 2 methods to assess knee cartilage defect size on preoperative MRI and determine their accuracy in predicting postdebridement defect sizes recorded during arthrotomy. It was hypothesized that defect size would be predicted more accurately by the total area of abnormal articular cartilage rather than the area of full-thickness cartilage loss as identified on MRI. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: This study included 64 patients (mean age, 41.8 ± 9.6 years) who underwent autologous cell therapy. Each patient received a 3-T MRI at 6.1 ± 3.0 weeks before cell implantation. Three raters, a radiologist, a surgeon, and a scientist, measured (1) the full-thickness cartilage defect area and (2) the total predicted abnormal cartilage area, identified by an abnormal signal on MRI. Interrater reliability was assessed using the intraclass correlation coefficient (ICC). Actual pre- and postdebridement defect sizes were obtained from intraoperative surgical notes. Postdebridement surgical measurements were considered the clinical reference standard and were compared with the radiologist's MRI measurements. Results: Eighty-seven defects were assessed, located on the lateral (n = 8) and medial (n = 26) femoral condyle, trochlea (n = 17), and patella (n = 36). The interrater reliability of the cartilage defect measurements on MRI was good to excellent for the full-thickness cartilage defect area (ICC = 0.74) and the total predicted abnormal cartilage area (ICC = 0.78). The median full-thickness cartilage defect area on MRI underestimated the median postdebridement defect area by 78.3%, whereas the total predicted abnormal cartilage area measurement underestimated the postdebridement defect area by 14.3%. Conclusion: Measuring the full-thickness cartilage defect area on MRI underestimated the area to treat, whereas measuring the total abnormal area provided a better estimate of the actual defect size for treatment. [ABSTRACT FROM AUTHOR]

Study Design: Systematic review and meta-analysis. Objective: Compilation of complication outcomes data from the surgical management of severe rigid kyphoscoliosis patients using VCR-based vs non-VCR-based corrective maneuvers is lacking. This meta-analysis aimed to compare complication outcomes between those classified osteotomy approaches. Methods: Thorough literature review and meta-analysis were conducted between January 2000 and September 2021. The selection criteria were studies: i) reporting major curve Cobb angle of ≥80° and flexibility of <25% or 30%; ii) comparing VCR or ≥ Type V Schwab osteotomy defined as VCR-based vs [non-VCR-based] techniques, (any osteotomy or technique other than VCR); iii) published in English with ≥10 patients; iv) reporting complication rates; and v) having minimum of 2-year follow-up. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. Significance level was set at (P <.05). Results: Of the 174 patients included, 52.30% (n = 91) and 47.70% (n = 83) were VCR-based and non-VCR-based, respectively. The incidence of dural tears/nerve injuries/significant intraoperative-neuromonitoring changes was significantly higher; [OR = 6.78, CI= (1.75 to 26.17), I2 = 0%, (P =.006)] in the VCR-based group than the non-VCR-based group. The 'overall surgical and medical' complication rate was significantly higher in the VCR-based group, [OR = 1.94, CI= (1.02 to 3.67), I2 = 31%, (P =.04)]. Conclusion: Both VCR-based and non-VCR-based surgical techniques for management of severe rigid scoliosis and kyphoscoliosis patients pose comparable overall surgical complication rates, while a significantly higher perioperative neurological complication incidence was associated with VCR-based technique compared to the non-VCR-based techniques. The VCR-based technique was associated with 6.78 times higher incidence of neurological complications compared to non-VCR-based techniques. [ABSTRACT FROM AUTHOR]

Study Design: Prospective randomized controlled trial. Objectives: Adjustment of endotracheal tube cuff pressure (ETCP) in anterior cervical discectomy and fusion (ACDF) may influence the incidence of complications such as recurrent laryngeal nerve palsy (RLNP), hoarseness, and dysphagia. Methods: The prospective randomized controlled trial was designed to investigate the influence of ETCP on the incidence of postoperative complications. All eligible patients underwent vocal cord examination before and after ACDF and were randomized into a control group (CG) and intervention group (IG). Endotracheal tube cuff pressure was passively monitored in CG, and in IG, it was maintained at 20 mmHg. Outcomes were evaluated during hospitalization and during follow-up. Results: A total of 98 patients were randomized, each group consisted of 49 patients. Statistical analysis showed that gender and age did not influence the incidence of complications. In CG, duration of retractor placement and extent of approach significantly impacted the occurrence of complications. The incidence of postoperative RLNP was 8.2% in IG and 12.2% in CG, hoarseness and dysphonia were present in 18.4% in IG and in 37.5% in CG, and dysphagia in 20.8% in IG and in 22.5% in CG. Hoarseness was significantly present more in CG (P =.018). Only one patient from CG presented with RLNP after 1 year, the remaining nine patients spontaneously recovered. Conclusions: Unregulated ETCP can lead to a significantly higher incidence of hoarseness; however, its improvement rate is 100%. The early postoperative complication rate was higher in CG, and after one year, 1 patient had RLNP and 1 patient had dysphagia. [ABSTRACT FROM AUTHOR]

Study Design: A Retrospective Cohort Study. Objective: To introduce a new Doppler sonography-assisted pedicle screw fixation technique that enables vertebral artery (VA) monitoring during surgery and compares the accuracies of Doppler sonography-assisted cervical pedicle screw fixation and the conventional technique. Methods: This retrospective study was performed on 164 consecutive patients that underwent pedicle-based screw fixation from C2 to C6 between January 2013 and August 2020. Surgery was performed without intraoperative Doppler sonography in 84 cases (the Control group) or with intraoperative Doppler sonography in 80 cases (the Doppler group). Proper positioning of pedicle screws was graded, and the incidences of VA injury and screw breach in the Control and Doppler groups were compared. Results: Three hundred and ninety-nine screws were placed in the 164 patients (Doppler, 186 screws; Control, 213 screws). The percentages of well-positioned screws in the two groups were significantly different (Doppler, 97.8%; Control, 85.0%). There were two cases of VA injury in the Control group, an incidence of 2.4%, but no case in the Doppler group. Conclusion: Doppler sonography can be used intraoperatively to help guide the trajectory of the cervical pedicle screw insertion. It can detect the VA inside the screw trajectory and may reduce the risk of VA injury during cervical pedicle screw fixation. [ABSTRACT FROM AUTHOR]

Objectives: To analyse the safety and efficacy of Thulium laser en bloc enucleation of bladder tumour (ThuLEBT) in comparison to transurethral resection of bladder tumour (TURBT) for treatment of non-muscle invasive bladder cancer (NMIBC). Methods: Prospective observational study involving 30 patients in each group of ThuLEBT and TURBT admitted in tertiary care centre from 1st January 2021 to December 2021. Results: Significant difference was found in terms of less operative time (p -0.01468), less intraoperative blood loss, a lower incidence of obturator nerve reflex (p -0.00006), bladder perforation (p -0.0455) and bladder irrigation (p -0.0027), better acquisition of detrusor muscle (p -0.0466), less recurrence rate (p -0.0455) in favour of ThuLEBT over TURBT group. The analysis also demonstrated faster postoperative recovery in terms of the duration of catheterisation, bladder irrigation and hospitalisation time in ThuLEBT group. Conclusions: ThuLEBT is an efficient and safe treatment for non-muscle invasive bladder cancer and it can be a better alternative choice in place of TURBT. [ABSTRACT FROM AUTHOR]

Study Design: Multicenter prospective study. Objectives: Although intramedullary spinal cord tumor (IMSCT) and extramedullary SCT (EMSCT) surgeries carry high risk of intraoperative motor deficits (MDs), the benefits of transcranial motor evoked potential (TcMEP) monitoring are well-accepted; however, comparisons have not yet been conducted. This study aimed to clarify the efficacy of TcMEP monitoring during IMSCT and EMSCT resection surgeries. Methods: We prospectively reviewed TcMEP monitoring data of 81 consecutive IMSCT and 347 EMSCT patients. We compared the efficacy of interventions based on TcMEP alerts in the IMSCT and EMSCT groups. We defined our alert point as a TcMEP amplitude reduction of ≥70% from baseline. Results: In the IMSCT group, TcMEP monitoring revealed 20 true-positive (25%), 8 rescue (10%; rescue rate 29%), 10 false-positive, a false-negative, and 41 true-negative patients, resulting in a sensitivity of 95% and a specificity of 80%. In the EMSCT group, TcMEP monitoring revealed 20 true-positive (6%), 24 rescue (7%; rescue rate 55%), 29 false-positive, 2 false-negative, and 263 true-negative patients, resulting in a sensitivity of 91% and specificity of 90%. The most common TcMEP alert timing was during tumor resection (96% vs. 91%), and suspension surgeries with or without intravenous steroid administration were performed as intervention techniques. Conclusions: Postoperative MD rates in IMSCT and EMSCT surgeries using TcMEP monitoring were 25% and 6%, and rescue rates were 29% and 55%. We believe that the usage of TcMEP monitoring and appropriate intervention techniques during SCT surgeries might have predicted and prevented the occurrence of intraoperative MDs. [ABSTRACT FROM AUTHOR]

Study Design: Systematic Literature Review. Objective: To propose a systematic imaging algorithm for diagnosing posterior ligamentous complex (PLC) injury in computed tomography (CT) and magnetic resonance imaging (MRI) to improve the reliability of PLC assessment. Methods: A systematic review was conducted following PRISMA guidelines. The Scopus database was searched from its inception until July 21, 2022, for studies evaluating CT or MRI assessment of the PLC injury following thoracolumbar trauma. The studies extracted key findings, objectives, injury definitions, and radiographic modalities. Results: Twenty-three studies were included in this systematic review, encompassing 2021 patients. Five studies evaluated the accuracy of MRI in detecting thoracolumbar PLC injury using intraoperative findings as a reference. These studies indicate that black stripe discontinuity due to supraspinous or ligamentum flavum rupture is a more specific criterion of PLC injury than high-signal intensity. Thirteen papers evaluated the accuracy or reliability of CT in detecting thoracolumbar PLC injury using MRI or intraoperative findings as a reference. The overall accuracy rate of CT in detecting PLC injury was 68-90%. Two studies evaluate the accuracy of combined CT findings, showing that ≥2 CT findings are associated with a positive predictive value of 88-91 %. Vertebral translation, facet joint malalignment, spinous process fracture, horizontal laminar fracture, and interspinous widening were independent predictors of PLC injury. Conclusion: We provided a comprehensive imaging algorithm for diagnosing PLC in CT and MRI based on available literature and our experience. The algorithm will potentially improve the accuracy and reliability of PLC assessment, however it needs multicentre prospective validation. [ABSTRACT FROM AUTHOR]

Background: In double-bundle anterior cruciate ligament (ACL) reconstruction, tunnel coalition may occur intraoperatively or during the postoperative course. Tibial tunnel coalition is more common compared with femoral tunnel coalition. Once tunnel coalition occurs on the tibial side, rotatory knee laxity may not be controlled as expected. We have developed a new device to avoid tibial tunnel coalition with consistency. The purpose of this video is to present the surgical technique for double-bundle ACL reconstruction using a new drill guide. Indications: The novel guide may be used in all cases with confirmed ACL tear in a physically active patient, identical to indications for current ACL reconstruction using the double-bundle technique. Technique Description: The hamstring tendon is harvested for the ACL grafts. Two guide pins for the anteromedial bundle and posterolateral bundle for the tibial tunnel are inserted through the Anatomic Double-Bundle 2-in-1 Guide System. Cannulated drills and dilators are used to create the tunnel to the final diameter. Next, femoral tunnels are created by the outside-in technique using the Anatomic Double-Bundle 2-in-1 Guide System. Grafts are inserted from the tibia and passed through the femur. The grafts are fixed with a post screw and/or interference screw. Results: Two weeks after surgery, no tibial or femoral coalition (0/20 cases) were confirmed and tibial bony bridge at the intraarticular surface was measured 2.7 ± 0.9 mm using computed tomography (CT). One year after surgery, tibial coalition was confirmed in 13.3% (2/15 cases), and femoral coalition in 6.7% (1/15 cases) on CT image mainly due to tunnel widening. The 2 cases with tibial coalition had tibial bony bridge of less than 2 mm on immediate postoperative CT. Discussion/Conclusion: Using the novel guide, 2 tibial tunnels were created easily and accurately compared with the conventional independent drilling technique. The 2 tunnels can also be created simultaneously with single placement of the guide. Two separate tunnels help maintain expected rotatory knee stability after double-bundle ACL reconstruction. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication. Graphical Abstract This is a visual representation of the abstract. [ABSTRACT FROM AUTHOR]

Objectives: Thyroidectomy and parathyroidectomy using the nerve integrity monitor (NIM) require proper placement of the endotracheal tube with electrodes aligned correctly within the larynx. The purpose of this study is to determine the percentage of patients who require positional adjustments of the endotracheal tube prior to beginning surgery and to understand the value of using the GlideScope to assure proper NIM tube placement within the larynx. Methods: This prospective study examines operative data from 297 patients who underwent NIM thyroidectomy and parathyroidectomy. After routine orotracheal intubation by an anesthesiologist and positioning of the patient for surgery, a GlideScope was used to check the position of the tube in 2 planes: depth of tube placement and rotation of the tube within the larynx assuring proper placement of the electromyogram electrodes within the glottis. Results: Tube adjustment was required for 66.5% of patients. In 48.1% of cases, tube retraction or advancement to a proper depth was needed. Tube rotation was required for 30.1% of patients, and 11.8% of patients required both adjustment of tube depth and tube rotation to properly align electrodes. Conclusions: After the anesthesiologist places the NIM endotracheal tube, and the patient is positioned for surgery, additional tube adjustment is often needed prior to the start of surgery. The GlideScope is readily available in the operating suite, its use adds little time to the procedure, and assures proper NIM tube placement. The use of the GlideScope is recommended. [ABSTRACT FROM AUTHOR]

We report a retrospective study of 112 nerve transfers in 39 participants to investigate predictors of strength outcomes after nerve transfer surgery for upper limb reanimation in tetraplegia. We measured clinical and pre- and intraoperative neurophysiological assessment variables and compared them with strength outcomes 2 years after nerve transfer surgery. We found statistically significant improvement in Medical Research Council strength grades after nerve transfer surgery with lower cervical spine injuries (between one and two grades), lower donor nerve stimulation thresholds (half of a grade), greater motor evoked potential activity in recipient nerves (half of a grade) and greater muscle responses to intraoperative stimulation of donor (half of a grade) and recipient nerves (half of a grade). Level of evidence: III [ABSTRACT FROM AUTHOR]

Introduction: Digital collateral ligament injuries are common hand injuries that can cause significant pain and functional impairment. Ultrasonography can be useful in the evaluation of these ligamentous injuries, as it is both cost-effective and allows for easy, dynamic evaluation during imaging. Case report: We report a rare sonographic finding of an index finger radial collateral ligament injury that was found to have a flap of the ligament entrapped within the metacarpophalangeal joint, which to our knowledge has not been described previously. We correlate this finding with an intraoperative image of the entrapment of the collateral ligament. We also report on the novel application of superb microvascular imaging to aid in the diagnosis of digital collateral ligament injury. Discussion: This particular injury pattern has not been reported in the literature previously and likely explains the patient's lack of improvement with nonoperative management. Our finding is similar to a Stener lesion seen in a thumb ulnar collateral ligament injury in which the ligament is unable to heal due to entrapment. In addition, using superb microvascular imaging (SMI), we were able to visualize hyperemia to surrounding structures and the ligament itself which suggested an acute injury. Conclusion: We anticipate that this case report will provide sonographers with knowledge and images of this specific injury pattern to the digital collateral ligaments. [ABSTRACT FROM AUTHOR]

Objectives: Medial patellofemoral ligament reconstruction is performed to address cases of patellar instability. Historically, this is a well-tolerated procedure though complications, including redislocation and recurrent instability can occur. While risk factors for redislocation following MPFLR have been proposed, there remains no agreed upon consensus. This is even more true in setting of isolated MPFL reconstruction, as concomitant procedures may naturally exclude certain anatomic risk factors. The purpose of this study was to correlate demographic, anatomical, and clinical risk factors to redislocation following isolated medial patellofemoral ligament reconstruction (MPFLR). Methods: A retrospective review of patients who underwent isolated MPFLR for recurrent patellar instability at a single institution between December 2015-June 2021 was performed. Included patients had a minimum of 2 years of follow-up data available. Demographic, pre-operative radiographic, surgical, and clinical data was compared between those who had a dislocation event after surgery and those who did not. Subluxation and subjective instability were not considered dislocation events. Independent samples T-test and univariate binary logistic regression was performed. Results: This study included 126 patients with a mean age of 21.74 ± 9.20 and a mean BMI of 25.93 ± 6.36. Of these, 67.5% were female and 61.9% of operations were on the left knee. In total, 8.7% (11/126) of patients experienced a redislocation event with a mean time to redislocation of 19.11 months after surgery (range 5 – 32 months). On preoperative magnetic resonance imaging (MRI), greater trochlear bump height measured to bone (p=0.032) and measured to cartilage (p=0.033) was associated with redislocation (Table 1). Additionally, patients who redislocated were found to have a wider sulcus angle (p=0.022). On examination under anesthesia, a greater flexion instability resolution angle – the angle of knee flexion at which the patella no longer dislocates – was found to be associated with redislocation (p=0.041) (Figure 1). These variables all retained significance during univariate regression. Conclusions: MPFLR is associated with a high level of success with a redislocation rate of 8.7% in this study. On pre-operative MRI, wide sulcus angle and increased bump height measured to bone and to cartilage were risk factors for redislocation. Additionally, redislocation was associated with a greater flexion instability resolution angle (IRA). [ABSTRACT FROM AUTHOR]

Objectives: Hip arthroscopy has become increasingly prevalent in the United States for treating young adult hip disorders. The periportal capsulotomy, in comparison to the interportal capsulotomy, has been proposed as a technique for decreasing post-arthroscopy hip instability; however, the effects of this technique are largely theoretical. The objectives of this study were to compare the intraoperative distraction profiles of hip arthroscopy patients undergoing interportal versus periportal capsulotomies. The authors hypothesized the periportal capsulotomy would demonstrate greater resistance to axial distraction at both 1) the capsulotomy and 2) final capsular repair, when compared to the interportal capsulotomy. Methods: Patients undergoing primary hip arthroscopy by a single surgeon underwent intraoperative axial distraction testing at 25-, 50-, 75-, and 100-pounds force with each axial distraction distance measured by standardized, normalized fluoroscopic evaluation. Demographics, hip radiographic characteristics, and distraction distance measurements were collected on patients undergoing periportal capsulotomy and on a historical control group undergoing an interportal capsulotomy (Figure 1). Propensity matching was conducted using native state distraction, lateral center edge angle, and gender as covariate to achieve balance between groups. Between group comparisons were then conducted across the matched interportal and periportal groups. Student's T-test for continuous variables and the Fisher exact test for categorical variables. Intragroup comparison was conducted across three capsule states: native, capsulotomy, and repair. Sequential testing of capsular states for each patient was conducted with the paired T-test. Results: Seventy-four interportal capsulotomies and 122 periportal capsulotomies were identified. Propensity matching yielded 74 hips in each group with standard mean differences of < 0.03. Demographic and radiographic characteristics were similar between matched cohorts (p > 0.05) (Table 1). Distraction distances were similar between the interportal and periportal groups in both the capsulotomy and repair states (p > 0.05), while the periportal capsulotomy repair demonstrated decreased hip distraction distance when compared to the native state by 1.48mm at 75lbf and 1.54mm at 100lbf (p < 0.001) (Figure 2). Conclusions: The present study demonstrates that periportal capsulotomy and interportal capsulotomy have similar effects on in vivo hip distractibility. An unrepaired interportal capsulotomy led to an increase in hip distraction of 2.71 mm at 100 lbf (p < 0.001) compared to the native state, while an unrepaired periportal capsulotomy led to an increase in hip distraction of 2.44 mm at 100 lbf (p < 0.001). [ABSTRACT FROM AUTHOR]

With advances in tumor treatment, metastasis to bone is increasing, and surgery has become the only choice for most terminal patients. However, spinal surgery has a high risk and is prone to heavy bleeding. Controlled hypotension during surgery has out- standing advantages in reducing intraoperative bleeding and ensuring a clear field of vision, thus avoiding damage to important nerves and vessels. Antihypertensive drugs should be carefully selected after considering the patient’s age, different diseases, etc, and a single or combined regimen can be used. Hypotension also inevitably leads to a decrease in perfusion of important organs, so the threshold of hypotension and the maintenance time of hypotension should be strictly limited, and the monitoring of important organs during the operation is particularly important. Information such as blood perfusion, blood oxygen saturation, cardiac output, and neurophysiological conduction potential changes should be obtained in a timely fashion, which will help to reduce the risk of hypotension. In short, when applying controlled hypotension, it is necessary to choose an appropriate thresh- old and duration, and appropriate monitoring should be conducted during the operation to ensure the safety of the patient. [ABSTRACT FROM AUTHOR]

With advances in tumor treatment, metastasis to bone is increasing, and surgery has become the only choice for most terminal patients. However, spinal surgery has a high risk and is prone to heavy bleeding. Controlled hypotension during surgery has outstanding advantages in reducing intraoperative bleeding and ensuring a clear field of vision, thus avoiding damage to important nerves and vessels. Antihypertensive drugs should be carefully selected after considering the patient's age, different diseases, etc, and a single or combined regimen can be used. Hypotension also inevitably leads to a decrease in perfusion of important organs, so the threshold of hypotension and the maintenance time of hypotension should be strictly limited, and the monitoring of important organs during the operation is particularly important. Information such as blood perfusion, blood oxygen saturation, cardiac output, and neurophysiological conduction potential changes should be obtained in a timely fashion, which will help to reduce the risk of hypotension. In short, when applying controlled hypotension, it is necessary to choose an appropriate threshold and duration, and appropriate monitoring should be conducted during the operation to ensure the safety of the patient. [ABSTRACT FROM AUTHOR]

Background: Comparable short-term outcomes have been obtained using hamstring allografts versus autografts after primary segmental labral reconstruction (SLR). Midterm results have not yet been determined. Purpose: (1) To evaluate minimum 5-year patient-reported outcome (PRO) scores in patients who underwent primary SLR with hamstring grafts in the setting of femoroacetabular impingement syndrome (FAIS) and irreparable labral tears and (2) to compare the outcomes of hamstring autografts versus allografts in a subanalysis using propensity-matched groups. Study Design: Cohort study; Level of evidence, 3. Methods: Prospectively collected data were retrospectively reviewed for patients who underwent primary hip arthroscopy between September 2010 and November 2015. Patients were included if they underwent SLR using hamstring autografts or allografts and had preoperative and minimum 5-year PROs. The exclusion criteria were previous ipsilateral hip surgery or conditions, dysplasia, or Tönnis grade >1. Patients with autograft SLR were propensity matched 1 to 1 based on age, sex, and body mass index (BMI) to patients who underwent SLR using hamstring allografts. The minimal clinically important difference (MCID) and the Patient Acceptable Symptom State (PASS) were calculated. Results: Overall, 48 patients (N = hips 48) were eligible to be included in this study, and 41 patients (n = 41 hips [85.4%]) had a minimum 5-year follow-up reporting significant improvements in all PROs. Within the entire cohort, 9.8% required a secondary arthroscopy, with a mean time of 19 ± 1.8 months, and survivorship was 82.9%. Of the 41 included patients, 15 underwent an SLR with a hamstring autograft and were matched to 15 patients with labral reconstruction using a hamstring allograft. Groups were similar for sex (P >.999), age (P =.775), and BMI (P =.486). The mean follow-up times were 80.8 ± 25.5 and 66.1 ± 8.3 months (P =.223) for the autograft and allograft groups, respectively. Baseline PROs, preoperative radiographic measurements, surgical findings, and intraoperative procedures were similar. The groups achieved significant and comparable improvements for all PROs (P <.0001), satisfaction (P =.187), and the rate of achieving the MCID and the PASS. However, a tendency for higher postoperative PROs favoring allograft reconstruction was found. Conclusion: At a minimum 5-year follow-up, patients who underwent primary arthroscopic SLR in the context of FAIS and irreparable labra, with either autograft or allograft hamstring tendons, reported significant improvements and comparable postoperative scores for all PROs, patient satisfaction, MCID, and PASS. [ABSTRACT FROM AUTHOR]

Background: It is important to maintain soft-tissue balance and prevent muscle contractures after hip reduction during total hip arthroplasty (THA) in patients with Crowe type IV developmental dysplasia of the hip (DDH). To make such hips functional and durable, the techniques to achieve soft-tissue balance were studied to create an algorithm for intraoperative 2-stage evaluation of muscle contractures, specifying the optimal order for contracture release. Methods: Between February 2011 and March 2015, we evaluated 64 patients (75 hips) with DDH for muscle contractures as they underwent THA. Following acetabular implantation, femoral osteotomy was applied of various lengths according to limb-length discrepancy. First, the distal part of the femur was prepared by broaching, and the hip was then reduced. The tensor fascia lata, rectus femoris, sartorius, hamstrings, and adductor muscles were evaluated, and any contractures were released. A trial conjoining of the distal and proximal parts of the femur was made, and the hip was reduced again. Finally, the iliopsoas and abductor muscles were evaluated, and contractures were released. Results: The mean follow-up duration was 4.6 years. Preoperative and postoperative Harris Hip Scores were 52 and 87, respectively. Limb-length discrepancy was mean 4.2 cm preoperatively, and <1 cm postoperatively. All contractures were released according to our newly developed algorithm. Conclusions: It is challenging to pinpoint the main muscle causing contractures, because other muscles acting on the hip joint have similar secondary functions. The method we describe here may provide better and more specific restoration of muscle function in a hypoplastic hemipelvis in DDH. [ABSTRACT FROM AUTHOR]

Background: The incidence of revision hip arthroscopy with labral reconstruction in athletes is increasing. However, the outcomes of revision hip arthroscopy with labral reconstruction in athletes have not been well established. Purposes: (1) To report minimum 2–year patient–reported outcome (PRO) scores and return to sports (RTS) characteristics for high–level athletes undergoing revision hip arthroscopy with labral reconstruction and (2) to compare clinical results with those of a propensity–matched control group of high–level athletes undergoing revision hip arthroscopy with labral repair. Study Design: Cohort study; Level of evidence, 3. Methods: Data were prospectively collected and retrospectively reviewed for athletes at any level who underwent a revision hip arthroscopy and a labral reconstruction between April 2010 and March 2019. Minimum 2–year PROs were reported for the modified Harris Hip Score (mHHS), the Nonarthritic Hip Score (NAHS), the Hip Outcome Score–Sport Specific Subscale (HOS-SSS), the visual analog scale (VAS) for pain, and RTS. The percentages of athletes achieving the minimal clinically important difference (MCID) and the maximum outcome improvement satisfaction threshold (MOIST) were also recorded. These patients were propensity matched in a 1: 1 ratio to athletes undergoing revision hip arthroscopy with labral repair for comparison. Results: A total of 46 athletes (N = 47 hips) were reported from 50 (n = 51 hips) athletes who underwent revision with labral reconstruction. A subanalysis of 30 propensity–matched athletes undergoing revision labral reconstruction was performed, with a mean follow–up time of 26.3 ± 2.4 months and an age of 28.5 ± 10.1 years, and compared with a revision labral repair group. Significant improvements were obtained for the mHHS, the NAHS, the HOS-SSS, and the VAS from preoperative to the latest follow–up (P <.001), with an achievement MCID rate of 61.5%, 72%, 62.5%, and 76.9% for the mHHS, the NAHS, the HOS-SSS, and the VAS, respectively. The rate for re–revision surgery (2 tertiary arthroscopy and 1 conversion to total hip arthroplasty) was 10%, and 14 patients (63.6%) were able to RTS. Improvements in PROs, rates of achieving MCID/MOIST, rate of re–revision surgery (re-revision hip arthroscopy, P =.671; conversion to total hip arthroplasty, P >.999), and RTS rate (P =.337) were similar when compared with those of the propensity–matched control labral repair group (P >.05). Conclusion: Revision hip arthroscopy with labral reconstruction, in the context of an irreparable labral tear, seems to be a valid treatment option in the athletic population, demonstrating significant improvements in all PROs and low rates of undergoing revision surgery. Athletes experienced a similar magnitude of improvement in PROs, RTS rate, and revision surgery rate to that of a propensity–matched control group of athletes undergoing revision hip arthroscopy with labral repair. [ABSTRACT FROM AUTHOR]

Background: Anti-vascular endothelial growth factor intravitreal injections (IVIs) have proved to be a boon for patients suffering from several retinal pathologies. They are one of the most commonly performed procedures in ophthalmology. A perioperative rise in blood pressure (BP) has been noted during cataract surgery. Objectives: To evaluate the perioperative BP changes during IVI, and the associated risk factors. Design: Cross-sectional observational study Methods: The patients undergoing IVI from May 2019 to August 2019 were evaluated. All the patients underwent BP measurement before, during, and 1 h after the IVI. The correlation between the demographics and, the systemic comorbidities of the patients, and the ocular condition for which IVI was given was evaluated. Results: The study included 302 patients (mean age of 59.9 ± 10.7 years). The mean increase in systolic BP (SBP) and diastolic BP (DBP) at the time of injection was 25.7 ± 21.0 and 1.3 ± 13.4 mmHg, respectively. A ⩾ 10, ⩾ 20, ⩾ 30 mmHg increase in SBP at the time of injection was seen in 83.8% (n = 253), 69.5% (n = 210) and 49.0% (n = 148) patients, respectively. Forty-one (13.6%) patients developed intra-procedural hypertensive urgency, out of which six patients (14.6%) did not recover even after 1 h of the procedure. None of the patients experienced any cardiovascular events. The univariate and multivariate linear regression analyses showed that the change in intra-procedural SBP correlated positively with the age of the patient and negatively with the baseline SBP. Conclusion: There is a significant rise of SBP at the time of IVI, especially in patients with advanced age and high baseline SBP. Some of the patients can experience hypertensive urgency at the time of injection and may take more than 1 h to recover. The patients receiving IVI should undergo a detailed physician evaluation before the procedure. [ABSTRACT FROM AUTHOR]

In a letter to the editor of the Global Spine Journal, Yew Long Lo critiques a study by Akbari et al on the effects of intraoperative neurophysiological changes during decompressive surgery for cervical myeloradiculopathy. Lo argues that the study's findings may be limited due to the lack of a standardized transcranial electrical stimulation (TES) protocol, which could have affected the achievement of supramaximal motor evoked potential (MEP) amplitude. Lo suggests that future research should focus on standardizing the TES protocol and recording muscles for MEP to ensure the validity of findings. [Extracted from the article]

Purpose The modified Dunn procedure for slipped capital femoral epiphysis (SCFE) remains controversial. We reviewed our series over ten years to report our learning curve, experience with intraoperative monitoring of femoral head perfusion and its correlation with postoperative Single-photon emission computed tomography (SPECT-CT) bone scan and femoral head collapse in stable and unstable SCFE. Methods We retrospectively assessed 217 consecutive modified Dunn procedures performed between 2008 and 2018. In all, 178 had a minimum of one-year follow-up (mean 2.7 years (1 to 9.2)) including 107 stable and 71 unstable SCFE. Postoperative viability was assessed with a three-phase Tc99 bone scan and SPECT-CT. From 2011, femoral head perfusion monitoring was performed intraoperatively using a Codman Intracranial Pressure transducer and the capsulotomy was modified. Results With intraoperative monitoring, the rate of non-viable femoral heads in stable SCFE decreased from 21.1% to 0% (p < 0.001). In unstable SCFE, the rate remained unchanged from 35.7% to 29.8% (p = 0.669). The positive predictive value (PPV) of pulsatile monitoring for no collapse was 100% in stable and 89.1% in unstable SCFE. Pulsatile monitoring and viable SPECT-CT bone scan gave a 100% PPV for all cases. A non-viable scan defines those hips at risk of collapse since 100% of stable and 68.2% of unstable hips with non-viable bone scans went on to collapse. Conclusion Our protocol enables safe performance of this complex procedure in stable SCFE with intraoperative monitoring being a reliable asset. The avascular necrosis rate for unstable SCFE remained unchanged and further research into its best management is required. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to test the non-inferiority of topical 1:1000 epinephrine compared to topical 1:10 000 with regard to intraoperative hemodynamic stability, and to determine whether it produced superior visibility conditions. Methods: A single-blinded, prospective, cross-over non-inferiority trial was performed. Topical 1:1000 or topical 1:10 000 was placed in 1 nasal passage. Hemodynamic parameters (heart rate, systolic and diastolic blood pressures, and mean arterial pressure) were measured prior to insertion then every minute for 10 minutes. This was repeated in the contralateral nasal passage of the same patient with the alternate concentration. The surgeon graded the visualization of each passage using the Boezaart Scale. The medians of the greatest absolute change in parameters were compared using a Wilcoxon Rank-Signed test and confidence intervals were calculated using a Hodges-Lehman test. The non-inferiority margin was pre-determined at 10 bpm for heart rate and 10 mmHg for blood pressures. A Wilcoxon Rank-Signed test was used to assess superiority in visualization. Results: Thirty-two patients were enrolled and after exclusions, nineteen were assessed (mean age = 35.63 ± 12.49). Differences in means of greatest absolute change between the 2 concentrations were calculated (heart rate = 2.49 ± 1.20; systolic = −1.51 ± 2.16; diastolic = 2.47 ± 1.47; mean arterial pressure = 0.07 ± 1.83). In analyses of medians, 1:1000 was non-inferior to the 1:10 000. There was a significant difference (–0.58 ± 0.84; P =.012) in visualization in favor of topical 1:1000. Conclusion: Topical 1:1000 epinephrine provides no worse intraoperative hemodynamic stability compared to topical 1:10 000 but affords superior visualization and should be used to optimize surgical conditions. [ABSTRACT FROM AUTHOR]

Background: The challenge of breast-conserving surgery (BCS) is to remove the entire tumour with free margins and avoid secondary excision that may adversely affect the cosmetic outcome. Consequently, intraoperative evaluation of surgical margins is critical. The aims of this study were multiple. First, to analyse our methodology of intraoperative examination of the resection margins and to evaluate radiological and pathological methods in the assessment of the surgical margins. Second, to evaluate the factors associated with positive margins in our patient population. M&m: The data on the resection margin status of 290 patients who underwent BCS for invasive carcinoma or ductal carcinoma in situ (DCIS) between 2009 and 2016 were reviewed. Results: In the cohort of BCS with invasive carcinoma, the negative predictive value was 97.4% for intraoperative assessment by radiography and 81.8% for intraoperative assessment by pathology. The re-operation rate among cases without intraoperative assessment was 23.6% compared to 7.3% among cases with intraoperative assessment (P =.003). Margin status was significantly associated with tumour size, histological subtype (invasive lobular carcinoma), and multifocality. In the population of BCS with DCIS, margin status was significantly associated with preoperative localisation and intraoperative margin assessment (P =.03). Conclusion: There is no statistical difference between pathological and radiological intraoperative assessment. Tumour size, lobular subtype, and multifocality were found to be significantly associated with positive margins in cases with invasive carcinoma, whereas absence of intraoperative margin assessment was significantly associated with positive margins in cases with DCIS. Therefore, intraoperative margin assessment improves the likelihood of complete excision of the lesion. [ABSTRACT FROM AUTHOR]

The use of electrocochleography (ECochG) for providing real-time feedback of cochlear function during cochlear implantation is receiving increased attention for preventing cochlear trauma and preserving residual hearing. Although various studies investigated the relationship between intra-operative ECochG measurements and surgical outcomes in recent years, the limited interpretability of ECochG response changes leads to conflicting study results and prevents the adoption of this method for clinical use. Specifically, the movement of the recording electrode with respect to the different signal generators in intracochlear recordings makes the interpretation of signal changes with respect to cochlear trauma difficult. Here, we demonstrate that comparison of ECochG signals recorded simultaneously from intracochlear locations and from a fixed extracochlear location can potentially allow a differentiation between traumatic and atraumatic signal changes in intracochlear recordings. We measured ECochG responses to 500 Hz tone bursts with alternating starting phases during cochlear implant insertions in six human cochlear implant recipients. Our results show that an amplitude decrease with associated near 180° phase shift and harmonic distortions in the intracochlear difference curve during the first half of insertion was not accompanied by a decrease in the extracochlear difference curve's amplitude (n = 1), while late amplitude decreases in intracochlear difference curves (near full insertion, n = 2) did correspond to extracochlear amplitude decreases. These findings suggest a role for phase shifts, harmonic distortions, and recording location in interpreting intracochlear ECochG responses. [ABSTRACT FROM AUTHOR]

Background: Patients presenting with lateral hip pain may pose a difficult diagnostic challenge, as pain can be due to various causes. Purpose/Hypothesis: The purpose was to identify risk factors and predictors for symptomatic hip abductor tears in a cohort of patients undergoing primary hip arthroscopy for femoroacetabular impingement syndrome. We hypothesized that body mass index (BMI), female sex, age, and presence of chondral damage would be significant predictors of hip abductor pathologies. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: Data were prospectively collected and retrospectively reviewed. Patients were included if they underwent primary hip arthroscopy between March 2009 and December 2019. Patients with Tönnis grade >1, previous hip conditions, incomplete radiographic data, or open procedures were excluded. All demographic variables, intraoperative measurements, and radiographic measurements were assessed using a bivariate analysis. A stepwise logistic regression was used to determine predictive variables. Results: In total, 255 hips with a hip abductor tear that underwent hip arthroscopy and 2106 hips without a tear that underwent hip arthroscopy were included. The stepwise logistic regression successfully created a predictive model using age, sex, BMI, lateral joint space, and alpha angle as variables. The efficiency of the predictive model was 90.7%, with an area under the curve of 0.894. The odds of having a hip abductor tear were 7.41 times higher in females (odds ratio [OR], 7.41; 95% CI, 4.61-11.9). Each additional year of age was associated with a 13.7% (OR, 1.137; 95% CI, 1.12-1.16) increase in the odds of having a tear. Similarly, with each 1-unit increase in BMI, the odds of having a tear increased by 3.4% (OR, 1.034; 95% CI, 1.01-1.06). Conclusion: This study successfully created a predictive model that identified female sex (OR, 7.41), increasing age (OR, 1.137 for each year), and increased BMI (OR, 1.034 for each unit of BMI) as significant independent predictors of the presence of hip abductor tears in patients undergoing hip arthroscopy for femoroacetabular impingement syndrome. This model can be used in support of physical examination and imaging suggestive of hip abductor pathology to preoperatively identify the probability of a symptomatic hip abductor tear in these patients. [ABSTRACT FROM AUTHOR]

Background: Malposition of the acetabular component mainly results from intraoperative pelvic motion and manual errors during cup placement. We investigated the outcomes of a device that uses a level indicator application of a smartphone to function as a pelvic tilt goniometer to assess intraoperative motion. The cup positions outside Lewinnek's safe zone were compared between the smartphone-assisted technique and the conventional method that uses a mechanical alignment guide. Methods: A randomised controlled trial was conducted among 64 patients receiving primary cementless total hip arthroplasties (THAs) via a posterolateral approach from June 2015 to February 2017. Acetabular components were implanted either by conventional technique (n = 32) or using smartphone technique (n = 32). Inclination and anteversion angles were measured in supine pelvic radiographs. Results: The inclination angle in the smartphone group was not significantly different from the conventional group (41.2° ± 3.9° vs. 40.3° ± 7.9°, p = 0.567). The anteversion angle was also similar (19.3 ± 3.8° vs 19.1° ± 5.9°, p = 0.856). However, the standard deviation of the angle in the smartphone group was significantly lower for inclination (p < 0.001) and anteversion (p = 0.016). There were 3 outliers (9.4%) in the smartphone group, but 13 (40.6%) in the conventional group (p = 0.008). The risk ratio was 0.23 (95% CI, 0.07–0.73). The risk difference was −0.31 (95% CI, –0.51– –0.11). Conclusion: The smartphone-assisted technique in THA improves the precision of cup placement and decreases the percentage of safe zone outliers. Thai Clinical Trials Registry (ID: TCTR20151123002). [ABSTRACT FROM AUTHOR]