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Background Several studies have shown mechanical alignment influences the outcome of TKA. Robotic systems have been developed to improve the precision and accuracy of achieving component position and mechanical alignment. Questions/purposes We determined whether robotic-assisted implantation for TKA (1) improved clinical outcome; (2) improved mechanical axis alignment and implant inclination in the coronal and sagittal planes; (3) improved the balance (flexion and extension gaps); and (4) reduced complications, postoperative drainage, and operative time when compared to conventionally implanted TKA over an intermediate-term (minimum 3-year) followup period. Methods We prospectively randomized 100 patients who underwent unilateral TKA into one of two groups: 50 using a robotic-assisted procedure and 50 using conventional manual techniques. Outcome variables considered were postoperative ROM, WOMAC scores, Hospital for Special Surgery (HSS) knee scores, mechanical axis alignment, flexion/extension gap balance, complications, postoperative drainage, and operative time. Minimum followup was 41 months (mean, 65 months; range, 41–81 months). Results There were no differences in postoperative ROM, WOMAC scores, and HSS knee scores. The robotic-assisted group resulted in no mechanical axis outliers (> ± 3° from neutral) compared to 24% in the conventional group. There were fewer robotic-assisted knees where the flexion gap exceeded the extension gap by 2 mm. The robotic-assisted procedures took an average of 25 minutes longer than the conventional procedures but had less postoperative blood drainage. There were no differences in complications between groups. Conclusions Robotic-assisted TKA appears to reduce the number of mechanical axis alignment outliers and improve the ability to achieve flexion-extension gap balance, without any differences in clinical scores or complications when compared to conventional manual techniques. Level of Evidence Level I, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Objectives This study was a multicenter evaluation of the SAVI SCOUT ® breast localization and surgical guidance system using micro-impulse radar technology for the removal of nonpalpable breast lesions. The study was designed to validate the results of a recent 50-patient pilot study in a larger multi-institution trial. The primary endpoints were the rates of successful reflector placement, localization, and removal. Methods This multicenter, prospective trial enrolled patients scheduled to have excisional biopsy or breast-conserving surgery of a nonpalpable breast lesion. From March to November 2015, 154 patients were consented and evaluated by 20 radiologists and 16 surgeons at 11 participating centers. Patients had SCOUT ® reflectors placed up to 7 days before surgery, and placement was confirmed by mammography or ultrasonography. Implanted reflectors were detected by the SCOUT ® handpiece and console. Presence of the reflector in the excised surgical specimen was confirmed radiographically, and specimens were sent for routine pathology. Results SCOUT ® reflectors were successfully placed in 153 of 154 patients. In one case, the reflector was placed at a distance from the target that required a wire to be placed. All 154 lesions and reflectors were successfully removed during surgery. For 101 patients with a preoperative diagnosis of cancer, 86 (85.1 %) had clear margins, and 17 (16.8 %) patients required margin reexcision. Conclusions SCOUT ® provides a reliable and effective alternative method for the localization and surgical excision of nonpalpable breast lesions using no wires or radioactive materials, with excellent patient, radiologist, and surgeon acceptance.

Objective Computer-assisted surgery (CAS) and patient-specific instrumentation (PSI) are digital techniques to improve the accuracy of implant positioning in total knee arthroplasty (TKA), but their effects on clinical outcomes are still in dispute. The objective of this trial is to evaluate the efficacy and safety of CAS and PSI compared to conventional instrumentation (CI) in TKA. Methods A prospective randomized controlled trial was conducted. A total of 135 patients undergoing TKA were randomized into CAS group, PSI group and CI group with 45 patients in each group. Primary outcome is the coronal mechanical axis of lower extremity. Secondary outcomes include Femoral Rotation Angle (FRA) of the femoral prosthesis, operation time, perioperative blood loss, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Forgotten Joint Score (FJS) and complications. Results Outliers of Hip-Knee-Ankle angle (HKA) were 24.4% in CI group, 17.8% in CAS group and 31.1% in PSI group respectively, and there was no significant difference among these 3 groups ( P  > 0.05). Outliers of FRA were 13.3% in CI group, 26.7% in CAS group and 11.1% in PSI group respectively with no significant difference ( P  > 0.05). Operation time was (66.67 ± 12.85)min, (81.67 ± 12.31)min and (52.78 ± 8.62)min in CI, CAS and PSI group. Operation time in CI was longer than PSI and shorter than CAS with significant difference ( P  < 0.01). There was no significant difference in comparison of blood loss, transfusion rate, postoperative WOMAC and FJS ( P  > 0.05). Conclusion CAS and PSI, compared with CI, did not significantly improve clinical outcomes including lower limb alignment, rotation of femoral prosthesis, blood loss, transfusion rate, and function scores. However, CAS was associated with prolonged operation time, whereas PSI resulted in a reduced operation time. Level of evidence Level II. Trial registration ChiCTR-INR-17,012,881 (registration date: 03/10/2017).

Background Precise insertion of pedicle screws is important to avoid injury to closely adjacent neurovascular structures. The standard method for the insertion of pedicle screws is based on anatomical landmarks (free-hand technique). Head-mounted augmented reality (AR) devices can be used to guide instrumentation and implant placement in spinal surgery. This study evaluates the feasibility and precision of AR technology to improve precision of pedicle screw insertion compared to the current standard technique. Methods Two board-certified orthopedic surgeons specialized in spine surgery and two novice surgeons were each instructed to drill pilot holes for 40 pedicle screws in eighty lumbar vertebra sawbones models in an agar-based gel. One hundred and sixty pedicles were randomized into two groups: the standard free-hand technique (FH) and augmented reality technique (AR). A 3D model of the vertebral body was superimposed over the AR headset. Half of the pedicles were drilled using the FH method, and the other half using the AR method. Results The average minimal distance of the drill axis to the pedicle wall (MAPW) was similar in both groups for expert surgeons (FH 4.8 ± 1.0 mm vs. AR 5.0 ± 1.4 mm, p = 0.389) but for novice surgeons (FH 3.4 mm ± 1.8 mm, AR 4.2 ± 1.8 mm, p = 0.044). Expert surgeons showed 0 primary drill pedicle perforations (PDPP) in both the FH and AR groups. Novices showed 3 (7.5%) PDPP in the FH group and one perforation (2.5%) in the AR group, respectively ( p > 0.005). Experts showed no statistically significant difference in average secondary screw pedicle perforations (SSPP) between the AR and the FH set 6-, 7-, and 8-mm screws ( p > 0.05). Novices showed significant differences of SSPP between most groups: 6-mm screws, 18 (45%) vs. 7 (17.5%), p = 0.006; 7-mm screws, 20 (50%) vs. 10 (25%), p = 0.013; and 8-mm screws, 22 (55%) vs. 15 (37.5%), p = 0.053, in the FH and AR group, respectively. In novices, the average optimal medio-lateral convergent angle (oMLCA) was 3.23° (STD 4.90) and 0.62° (STD 4.56) for the FH and AR set screws ( p = 0.017), respectively. Novices drilled with a higher precision with respect to the cranio-caudal inclination angle (CCIA) category ( p = 0.04) with AR. Conclusion In this study, the additional anatomical information provided by the AR headset superimposed to real-world anatomy improved the precision of drilling pilot holes for pedicle screws in a laboratory setting and decreases the effect of surgeon’s experience. Further technical development and validations studies are currently being performed to investigate potential clinical benefits of the herein described AR-based navigation approach.

Background Improper acetabular component orientation in THA has been associated with increased dislocation rates, component impingement, bearing surface wear, and a greater likelihood of revision. Therefore, any reasonable steps to improve acetabular component orientation should be considered and explored. Questions/purposes We therefore sought to compare THA with a robotic-assisted posterior approach with manual alignment techniques through a posterior approach, using a matched-pair controlled study design, to assess whether the use of the robot made it more likely for the acetabular cup to be positioned in the safe zones described by Lewinnek et al. and Callanan et al. Methods Between September 2008 and September 2012, 160 THAs were performed by the senior surgeon. Sixty-two patients (38.8%) underwent THA using a conventional posterior approach, 69 (43.1%) underwent robotic-assisted THA using the posterior approach, and 29 (18.1%) underwent radiographic-guided anterior-approach THAs. From September 2008 to June 2011, all patients were offered anterior or posterior approaches regardless of BMI and anatomy. Since introduction of the robot in June 2011, all THAs were performed using the robotic technique through the posterior approach, unless a patient specifically requested otherwise. The radiographic cup positioning of the robotic-assisted THAs was compared with a matched-pair control group of conventional THAs performed by the same surgeon through the same posterior approach. The safe zone (inclination, 30°–50°; anteversion, 5°–25°) described by Lewinnek et al. and the modified safe zone (inclination, 30°–45°; anteversion, 5°–25°) of Callanan et al. were used for cup placement assessment. Matching criteria were gender, age ± 5 years, and (BMI) ± 7 units. After exclusions, a total of 50 THAs were included in each group. Strong interobserver and intraobserver correlations were found for all radiographic measurements (r > 0.82; p < 0.001). Results One hundred percent (50/50) of the robotic-assisted THAs were within the safe zone described by Lewinnek et al. compared with 80% (40/50) of the conventional THAs (p = 0.001). Ninety-two percent (46/50) of robotic-assisted THAs were within the modified safe zone described by Callanan et al. compared with 62% (31/50) of conventional THAs p (p = 0.001). The odds ratios for an implanted cup out of the safe zones of Lewinnek et al. and Callanan et al. were zero and 0.142, respectively (95% CI, 0.044, 0.457). Conclusions Use of the robot allowed for improvement in placement of the cup in both safe zones, an important parameter that plays a significant role in long-term success of THA. However, whether the radiographic improvements we observed will translate into clinical benefits for patients—such as reductions in component impingement, acetabular wear, and prosthetic dislocations, or in terms of improved longevity—remains unproven. Level of Evidence Level III, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.

Abstract BACKGROUND: Five-aminolevulinic acid (5-ALA) is used for fluorescence-guided resections of malignant glioma at a dose of 20 mg/kg; yet, it is unknown whether lower doses may also provide efficacy. OBJECTIVE: To perform a double-blinded randomized study comparing 3 different doses of 5-ALA. METHODS: Twenty-one patients with suspected malignant glioma were randomly assigned to 0.2, 2, or 20 mg/kg 5-ALA. Investigators were unaware of dose. Intraoperatively, regions of interest were first defined in tumor core, margin, and adjacent white matter under white light. Under violet–blue illumination, the surgeon's impression of fluorescence was recorded per region, followed by spectrometry and biopsy. Plasma was collected after administration and analyzed for 5-ALA and protoporphyrin IX (PPIX) content. RESULTS: The positive predictive value of fluorescence was 100%. Visual and spectrometric fluorescence assessment showed 20 mg/kg to elicit the strongest fluorescence in tumor core and margins, which correlated with cell density. Spectrometric and visual fluorescence correlated significantly. A 10-fold increase in 5-ALA dose (2-20 mg/kg) resulted in a 4-fold increase of fluorescence contrast between marginal tumor and adjacent brain. tmax for 5-ALA was 0.94 h for 20 mg/kg (0.2 kg: 0.50 h, 2 mg/kg: 0.61 h). Integrated PPIX plasma levels were 255.8 and 779.9 mcg*h/l (2 vs 20 mg/kg). Peak plasma concentrations were observed at 1.89 ± 0.71 and 7.83 ± 0.68 h (2 vs 20 mg/kg; average ± Standard Error of Mean [SEM]). CONCLUSION: The highest visible and measurable fluorescence was yielded by 20 mg/kg. No fluorescence was elicited at 0.2 mg/kg. Increasing 5-ALA doses did not result in proportional increases in tissue fluorescence or PPIX accumulation in plasma, indicating that doses higher than 20 mg/kg will not elicit useful increases in fluorescence.

Background To compare the accuracy of dental implant placement using a novel dental implant robotic system (THETA) and a dynamic navigation system (Yizhimei) by a vitro model experiment. Methods 10 partially edentulous jaws models were included in this study, and 20 sites were randomly assigned into two groups: the dental implant robotic system (THETA) group and a dynamic navigation system (Yizhimei) group. 20 implants were placed in the defects according to each manufacturer’s protocol respectively. The implant platform, apex and angle deviations were measured by fusion of the preoperative design and the actual postoperative cone-beam computed tomography (CBCT) using 3D Slicer software. Data were analyzed by t - test and Mann-Whitney U test, p  < 0.05 was considered statistically significant. Results A total of 20 implants were placed in 10 phantoms. The comparison deviation of implant platform, apex and angulation in THETA group were 0.58 ± 0.31 mm, 0.69 ± 0.28 mm, and 1.08 ± 0.66 ° respectively, while in Yizhimei group, the comparison deviation of implant platform, apex and angulation were 0.73 ± 0.20 mm, 0.86 ± 0.33 mm, and 2.32 ± 0.71 ° respectively. The angulation deviation in THETA group was significantly smaller than the Yizhimei group, and there was no significant difference in the deviation of the platform and apex of the implants placed using THETA and Yizhimei, respectively. Conclusion The implant positioning accuracy of the robotic system, especially the angular deviation was superior to that of the dynamic navigation system, suggesting that the THETA robotic system could be a promising tool in dental implant surgery in the future. Further clinical studies are needed to evaluate the current results.

BackgroundAchieving an optimal limb alignment is an important factor affecting the long-term survival of total knee arthroplasty (TKA). This is the first study to look at the limb alignment and orientation of components in TKA using a novel image-free handheld robotic sculpting system.MethodsThis case-controlled study retrospectively compared limb and component alignment of 77 TKAs performed with a robot (Robot-group) with a matched control group of patients who received conventional alignment with intramedular rods (Control group). Alignment and component positioning was measured on full-leg weight-bearing and standard lateral X-rays by two independent observers. The image-free handheld robotic sculpting system calculated the planned and achieved mechanical axis (MA). Outliers were defined as > 3° deviation from planned alignment.ResultsMean MA was 180.1° (SD = 1.9) in the Robot-group, compared to the Control group with a mean MA of 179.1° (SD = 3.1, p = 0.028). We observed 5 outliers (6%) in the Robot-group and 14 outliers (18%, p = 0.051) in the Control group. Fraction of outliers of the frontal tibial component was 0% in the Robot-group versus 8% in the Control group (p = 0.038). There were no other statistical differences regarding the implant positioning between both groups.ConclusionThe Robot-group showed significantly less outliers compared to the conventional technique. Whether these differences are clinically relevant is questionable and should be investigated on the long term. Randomized controlled trials with larger patient series will be needed in the future to confirm our preliminary results.

Purpose To assess the accuracy of O-arm-navigation-based pedicle screw insertion in dystrophic scoliosis secondary to NF-1 and compare it with free-hand pedicle screw insertion technique. Methods 32 patients with dystrophic NF-1-associated scoliosis were divided into two groups. A total of 92 pedicle screws were implanted in apical region (two vertebrae above and below the apex each) in 13 patients using O-arm-based navigation (O-arm group), and 121 screws were implanted in 19 patients using free-hand technique (free-hand group). The postoperative CT images were reviewed and analyzed for pedicle violation. The screw penetration was divided into four grades: grade 0 (ideal placement), grade 1 (penetration <2 mm), grade 2 (penetration between 2 and 4 mm), and grade 3 (penetration >4 mm). Results The accuracy rate of pedicle screw placement (grade 0, 1) was significantly higher in the O-arm group (79 %, 73/92) compared to 67 % (81/121) of the free-hand group ( P  = 0.045). Meanwhile, a significantly lower prevalence of grade 2–3 perforation was observed in the O-arm group (21 vs. 33 %, P  < 0.05), and the incidence of medial perforation was significantly minimized by using O-arm navigation compared to free-hand technique (2 vs. 15 %, P  < 0.01). Moreover, the implant density in apical region was significantly elevated by using O-arm navigation (58 vs. 42 %, P  < 0.001). Conclusion We reported 79 % accuracy of O-arm-based pedicle screw placement in dystrophic NF-1-associated scoliosis. O-arm navigation system does facilitate pedicle screw insertion in dystrophic NF-1-associated scoliosis, demonstrating superiorities in the safety and accuracy of pedicle screw placement in comparison with free-hand technique.

BackgroundLaparoscopic surgery has well-established benefits for patients; however, laparoscopic procedures have a long and difficult learning curve, in large part due to the lack of stereoscopic depth perception. Developments in high-definition and stereoscopic imaging have attempted to overcome this. Three-dimensional high-definition (3D HD) systems are thought to improve operating times compared to two-dimensional high-definition systems. However their performance against new, ultra-high-definition (‘4K’) systems is not known.MethodsPatients undergoing laparoscopic cholecystectomy were randomised to 3D HD or 4K laparoscopy. Operative videos were recorded, and the time from gallbladder exposure to separation from the liver (minus on table cholangiogram) was calculated. Blinded video assessment was performed to calculate intraoperative error scores.ResultsOne hundred and twenty patients were randomised, of which 109 were analysed (3D HD n = 54; 4K n = 55). No reduction in operative time was detected with 3D HD compared to 4K laparoscopy (median [IQR]; 23.41 min [17.00–37.98] vs 20.90 min [17.67–33.03]; p = 0.91); nor was there any decrease observed in error scores (60 [56–62] vs 58 [56–60]; p = 0.27), complications or reattendance. Stone spillage occurred more frequently with 3D HD, but there were no other differences in individual error rates. Gallbladder grade and operating surgeon had significant effects on time to complete the operation. Gallbladder grade also had a significant effect on the error score.ConclusionsA 3D HD laparoscopic system did not reduce operative time or error scores during laparoscopic cholecystectomy compared with a new 4K imaging system.