CT-based patient-specific instrumentation for total knee arthroplasty in over 700 cases: single-use instruments are as accurate as standard instruments.

PURPOSE: Efforts in total knee arthroplasty are made to improve accuracy for a correct leg axis and reduce component malpositioning using patient-specific instruments. It was hypothesized that use of patient-specific instruments (vs. computer-navigated and conventional techniques) will reduce the number of outliers. Our second hypothesis was that single-use instrumentation will lead to the same accuracy compared to patient-specific instruments made of metal. METHODS: 708 primary total knee arthroplasties between 2014 and 2018 using computer tomography (CT)-based patient-specific cutting block technique and a preoperative planning protocol were retrospectively reviewed. Preoperative data [hip-knee-angle (HKA), lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), tibial slope, femoral component flexion] was compared to postoperative performed standard radiological follow-up X-rays. Differences of > 3° between measurements were defined as outliers. RESULTS: Overall 500 prostheses using standard instrumentation and 208 prostheses using single-use instruments were implanted. Preoperative HKA axes (- 1.2°; p < 0.001), femoral component flexion (Δ 0.8°, p < 0.001), LDFA (Δ - 1.5°, p < 0.001), MPTA (Δ - 0.5°, p < 0.001) and tibial posterior slopes (Δ 0.5°, p < 0.001), respectively, were different from postoperative axes. More outliers occurred using standard (vs. single-use) instruments (p < 0.001) regarding postoperative HKA (ranges of standard- vs. single-use: instruments: HKA 178.0°-180.5° vs. 178.0°-180.5°, femoral component flexion 0.0°-6.0° vs. 0.0°-4.5°, LDFA 90.0°-91.0° vs. 90.0°-90.0°, MPTA 90.0°-90.0° vs. 90.0°-90.0°, tibial posterior slope - 10° to 10° vs. - 1° to 10°). No differences were seen for other angles measured. Comparing both systems, total number of outliers was higher using standard (8%) vs. single-use instruments (4.3%). CONCLUSION: This study shows a high accuracy of CT-based patient-specific instrumentation concerning postoperative achieved knee angles and mechanical leg axes. Single-use instruments showed a similar accuracy. LEVEL OF EVIDENCE: III.

Is it worth to explore the contralateral side in unilateral childhood inguinal hernia?: A PRISMA-compliant meta-analysis.

BACKGROUND: It is still not clear if the contralateral side should be explored in children with unilateral inguinal hernias. The primary aim of the present study was to assess the incidence of metachronous contralateral inguinal hernias (MCIHs) in the pediatric population. The second aim was to assess factors associated with increased risk of MCIH development. METHODS: Prospective studies including patients from 0-19 years undergoing unilateral inguinal hernia repair without surgical exploration of the contralateral side between 1947 and April 2020 with a minimal follow-up of one year were searched. Searches included EMBASE, MEDLINE, and the Cochrane Central Register of Controlled Trials. RESULTS: Seven studies involving 1774 children (1452 boys (82%) and 322 girls (18%) were identified. Overall the incidence of MCIH was 6%. Incidence of MCIH development was significantly higher in children with initial left-sided (9%) versus right-sided (3%) hernia (OR 2.55 with 95% CI from 1.56 to 4.17; P = 0.0002), in female (8%) versus male (4%) children (OR 1.74 with 95% CI from 1.01 to 3.01; P = 0.0469) and in patients with open (14%) versus closed (3%) contralateral processus vaginalis (CPV) (OR 4.17 with 95% CI from 1.25 to 13.9; P = 0.0202). There was no significant difference in MCIH development depending on follow-up duration (follow-up of ≤2 years (i.e. 1-2 years): calculated MCIH incidence 5% (95% CI from 0.00 to 0.11%; 3 studies; 569 patients), follow-up of ≥3 years (i.e. 3-4 years): 6% (95% CI from 0.03 to 0.09; 3 studies, 983 patients)) or patients' age (MCIH incidence in children <1 year: 6.9%; older children: 4.5%; OR 1.87 with 95% CI from 0.97 to 3.62; P = 0.0618). CONCLUSIONS: Overall incidence of MCIH development is 6%. Initial left-sided hernia, female gender and open CPV are risk factors for MCIH development.

Evidence according to Cochrane Systematic Reviews on Alterable Risk Factors for Anastomotic Leakage in Colorectal Surgery.

Anastomotic leakage reflects a major problem in visceral surgery, leading to increased morbidity, mortality, and costs. This review is aimed at evaluating and summarizing risk factors for colorectal anastomotic leakage. A generalized discussion first introduces risk factors beginning with nonalterable factors. Focus is then brought to alterable impact factors on colorectal anastomoses, utilizing Cochrane systematic reviews assessed via systemic literature search of the Cochrane Central Register of Controlled Trials and Medline until May 2019. Seventeen meta-anaylses covering 20 factors were identified. Thereof, 7 factors were preoperative, 10 intraoperative, and 3 postoperative. Three factors significantly reduced the incidence of anastomotic leaks: high (versus low) surgeon's operative volume (RR = 0.68), stapled (versus handsewn) ileocolic anastomosis (RR = 0.41), and a diverting ostomy in anterior resection for rectal carcinoma (RR = 0.32). Discussion of all alterable factors is made in the setting of the pre-, intra-, and postoperative influencers, with the only significant preoperative risk modifier being a high colorectal volume surgeon and the only significant intraoperative factors being utilizing staples in ileocolic anastomoses and a diverting ostomy in rectal anastomoses. There were no measured postoperative alterable factors affecting anastomotic integrity.

Impact of Sleep Deprivation on Surgical Laparoscopic Performance in Novices: A Computer-based Crossover Study.

OBJECTIVE: The 24-hour work shifts are newly permitted to first-year surgical residents in the United States. Whether surgery novices' motor activity is affected by sleep deprivation is controversial. MATERIALS AND METHODS: This study assesses sleep deprivation effects in computer-simulated laparoscopy in 20 surgical novices following 24 hours of sleep deprivation and after resting using a virtual-reality trainer. Participants were randomly assigned to perform simulator tests either well rested or sleep deprived first. RESULTS: Of 3 different tasks performed, no significant differences in total time to complete the procedure and average speed of instruments were found. Instrument path length was longer following sleep deprivation (P=0.0435) in 1 of 3 tasks. Error rates (ie, noncauterized bleedings, perforations, etc.), as well as precision, and accuracy rates showed no difference. None of the assessed participants' characteristics affected simulator performance. CONCLUSIONS: Twenty-four hours of sleep deprivation does not affect laparoscopic performance of surgical novices as assessed by computer-simulation.