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This paper presents a novel four degree of freedom haptic system for virtual reality knee arthroscopy training. The compact device, named OrthoForce, has a large workspace and force feedback in all axes (yaw, pitch, roll and translation). The robust device uses a novel haptic rendering algorithm to provide smooth haptic response at multiple simultaneous contact points anywhere along the tool (including twist feedback with the hook). It is capable of displaying high impedances that realistically simulate the impact with hard objects. In particular, the novel use of a ball screw spline provides a maximum impedance of 20 N/mm for translation as well as roll torque feedback in a small structure. Not only does this device meet the requirements for haptic use in knee arthroscopy training, but due to its small size and large range of motion, it has applications in other virtual reality training systems for a range of minimally invasive procedures.

Background: Ulnar neuropathy at the elbow is the second most common upper extremity compressive neuropathy and surgical treatment often involves surgical trainee involvement. The primary aim of this study is to determine the effect of trainees and surgical assistants on outcomes surrounding cubital tunnel surgery.

Methods: This retrospective study included 274 patients with cubital tunnel syndrome who underwent primary cubital tunnel surgery at two academic medical centres between 1 June 2015 and 1 March 2020. The patients were divided into four main cohorts based on primary surgical assistant: physician associates (PA, n = 38), orthopaedic or plastic surgery residents (n = 91), hand surgery fellows (n = 132), or both residents and fellows (n = 13). Exclusion criteria included patient age <18 years, revision surgery as the index procedure, prior traumatic ulnar nerve injury and concurrent procedures not related to cubital tunnel surgery. Demographics, clinical variables and perioperative findings were collected through chart reviews. Univariate and bivariate analyses were performed, and p < 0.05 was considered significant.

Results: Patients in all cohorts had similar demographic and clinical characteristics. There was a significantly higher rate of subcutaneous transposition in the PA cohort (39.5% PA vs. 13.2% Resident vs. 19.7% Fellow vs. 15.4% Resident + Fellow). Presence of surgical assistants and trainees had no association with length of surgery, complications and reoperation rates. Although male sex and ulnar nerve transposition were associated with longer operative times, no explanatory variables were associated with complications or reoperation rates.

Conclusions: Surgical trainee involvement in cubital tunnel surgery is safe and has no effect on operative time, complications or reoperation rates. Understanding the role of trainees and measuring the effect of graduated responsibility in surgery is important for medical training and safe patient care.

Level of Evidence: Level III (Therapeutic)

Background: The objective of this study was to assess whether resident involvement in distal radius fracture open reduction internal fixation (ORIF) affect 30-day postoperative complication, hospital readmission, reoperation and operative time.

Methods: A retrospective study was performed using the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) database by querying the Current Procedural Terminology (CPT) codes for distal radius fracture ORIF from 1 January 2011 to 31 December 2014. A final cohort of 5,693 adult patients who underwent distal radius fracture ORIF during the study period were included. Baseline patient demographics and comorbidities, intraoperative factors, including operative time and 30-day postoperative outcomes, including complications, readmission and reoperations, were collected. Bivariate statistical analyses were performed to identify variable associated with complication, readmission, reoperation and operative time. The significance level was adjusted using a Bonferroni correction as multiple comparisons were performed.

Results: In this study of 5,693 patients who underwent distal radius fracture ORIF, 66 patients had a complication, 85 patients were readmitted and 61 patients underwent reoperation within 30 days of surgery. Resident involvement in the surgery was not associated with 30-day postoperative complication, readmission or reoperation, but was associated with longer operative time. Moreover, 30-day postoperative complication was associated with older age, American Society of Anesthesiologists (ASA) classification, chronic obstructive pulmonary disease (COPD), congestive heart failure (CHF), hypertension and bleeding disorder. Thirty-day readmission was associated with older age, ASA classification, diabetes mellitus, COPD, hypertension, bleeding disorder and functional status. Thirty-day reoperation was associated with higher body mass index (BMI). Longer operative time was associated with younger age, male sex and the absence of bleeding disorder.

Conclusions: Resident involvement in distal radius fracture ORIF is associated with longer operative time, but no difference in rates of episode-of-care adverse events. Patients may be reassured that resident involvement in distal radius fracture ORIF does not negatively impact short-term outcomes.

Level of Evidence: Level IV (Therapeutic)

Minimally invasive endovascular interventions have evolved rapidly over the past decade, facilitated by breakthroughs in medical imaging and sensing, instrumentation and most recently robotics. Catheter-based operations are potentially safer and applicable to a wider patient population due to the reduced comorbidity. As a result endovascular surgery has become the preferred treatment option for conditions previously treated with open surgery and as such the number of patients undergoing endovascular interventions is increasing every year. This fact coupled with a proclivity for reduced working hours results in a requirement for efficient training and assessment of new surgeons, that deviates from the “see one, do one, teach one” model introduced by William Halsted, so that trainees obtain operational expertise in a shorter period. Developing more objective assessment tools based on quantitative metrics is now a recognized need in interventional training and this manuscript reports the current literature for endovascular skills assessment and the associated emerging technologies. A systematic search was performed on PubMed (MEDLINE), Google Scholar, IEEXplore and known journals using the keywords, “endovascular surgery”, “surgical skills”, “endovascular skills”, “surgical training endovascular” and “catheter skills”. Focusing explicitly on endovascular surgical skills, we group related works into three categories based on the metrics used; structured scales and checklists, simulation-based and motion-based metrics. This review highlights the key findings in each category and also provides suggestions for new research opportunities towards fully objective and automated surgical assessment solutions.

Trocar insertion is a critical first step of all minimally invasive surgery; however, it also carries a high risk for errors. Studies suggest that entry errors are the most common complication in laparoscopic surgery with 4% of errors leading to patient fatality. Surgeon error due to excessive force is often the cause for entry errors; however, adequate training has been shown to reduce the risk of these surgical errors. In practice, institutions lack widespread and relatively inexpensive means to train surgeons for trocar entry that does not involve patient risk. In our prior work, we presented a simple Stewart platform haptic device with a numerical model to simulate key force characteristics of trocar insertion. Evaluation in our first study was limited to device characterization. In this paper, we present a more robust haptic mechanism with higher fidelity linear actuators, an increased workspace, and tissue visualization to accompany haptic cues. We also present a novel upper module that allows for a sudden drop of the trocar after the final puncture event to create a more realistic simulation. We performed a user study with eight novices to investigate how well the device and visualization train users in the trocar insertion procedure. By the end of the experiment, subjects using the device had a normalized error reduction of roughly 85% on average, relative to themselves. This device shows potential for widespread training of trocar insertion, possibly leading to fewer complications and deaths following the procedure. Finally, our upper module also represents an innovative addition for traditional admittance-type haptic device designs, not typically capable of accurately representing motion in free space.