Accuracy of Toric Intraocular Lens Axis Alignment Using Manual Slit Lamp Method and CALLISTO Eye Image-Guided System

Aims: Image-guided systems are the gold standard for determining toric intraocular lens (IOL) axis alignment. However, their high cost prevents widespread use of these systems. As an alternative, a simpler and affordable method could be performed manually using a slit-lamp biomicroscope. This study aims to compare the accuracy of manual toric IOL axis marking using a slit-lamp compared to the CALLISTO eye image-guided system.Study Design: Prospective comparativeMethods: In this prospective study, toric IOL axis alignment of 42 eyes with cataract and coexisting corneal astigmatism were evaluated using manual slitlamp method and CALLISTO eye image-guided method. Preoperative and postoperative uncorrected visual acuity, best corrected visual acuity, amount of spherical and astigmatic refractive errors, and postoperative IOL axis alignment were evaluated. Intraclass correlation of the manual method was calculated and the difference of IOL axis alignment to the image-guided method was compared.Results: Toric IOL implantation reduced the amount of astigmatic refractive error from -1.63 � 0.65 D to -0.50 � 0.19 D in the image-guided group and from -1.93 � -0.90 D to -0.87 � 0.26 D in the manual slitlamp group. As many as 90.5% of eyes in the image-guided group and 81.0% of eyes in the manual slitlamp group reached the target induced astigmatism (p=0.38). Manual axis marking showed intraclass correlation of 99.3%. However, when the manual method was compared to the image-guided method a mean difference in axis alignment of 10.98o (95% confidence interval: 9.32o - 12.63o) was observed.Conclusions: Alignment of toric IOL axis using the manual method demonstrated a consistent result; yet producing a considerable difference to the result of the image-guided method.

The Advantages of Navigation for a Novice Surgeon in Performing Total Knee Replacement Surgery / 대한정형외과학회잡지

PURPOSE: To compare the outcomes of navigation-assisted total knee replacement conducted by a skilled surgeon and novice surgeon, as well as to evaluate the usefulness of the navigation assistance to a novice surgeon. MATERIALS AND METHODS: We retrospectively made a comparison between 60 total knee replacement surgeries conducted by skilled surgeon and 60 total knee replacement surgeries by a novice surgeon during the 2015. Scanograms were taken both preoperatively and at 3-month postoperatively to measure the accuracy of bone cutting and alignment. As for external rotation of the femur, we checked the values of the distal femur surgical epicondyle axis, and the posterior condyle axis displaced by the navigator after bone registration for both novice and skilled groups. For postoperative functional examination, Knee Society Score (KSS) were evaluated at 1-year follow-up. RESULTS: Forty-nine knees in the skilled group, and 51 knees in the novice group achieved coronal axis alignment of hip knee ankle values of 0°±3°. The mean external rotation degree of the femoral epicondyle axis against the posterior condyle axis, measured by the navigator, was 3.8°±2.9° in skilled group, and 1.2°±3.0° in novice group. When regarding femoral epicondyle axis, which showed a more internal rotation than the posterior condylar axis as an outlier, six cases were outlier in skilled group, while, 18 cases were outlier in novice group. After revising external rotation value of femoral implants comparing values navigation displaced and values using 3° external rotation manual jig against femoral posterior condylar axis, the skilled group showed 0 case of outlier and the novice group showed 10 cases of outlier. The mean KSS knee assessed at 1 year postoperatively was 83.2±6.8 in skilled group, and 83.1±7.0 in novice group, with no statistically significant difference. CONCLUSION: Navigation provides advantages to novice surgeon to achieve stabilized coronal plane axis, as well as accurate resection of the femur and tibia. However, the navigation does not provide any advantages in achieving the aimed amount of femoral external rotation to novice surgeons.

Cemented Femoral Component with Centralizing Device : Is it Effective for Centralization and for Attainment of Optimal Cement Mantle Thickness ? / 대한정형외과학회잡지

To evaluate the effectiveness of centralizing device, three groups of patients on whom cemented total hip arthroplasty with three types of implant was performed respectively were analyzed and compared; SL stems without centralizing device were used in Group I, Interlok stems with central sleeve in Group II, and MS-30 stems with distal centralizer in Group III .The size of each group was 20. Cement mantle thickness, the amount of displacement of stem tip, and axis alignment of femoral stem on A-P radiograph checked at 2 weeks after operation were assessed. More optimal cement mantle thickness (3~6mm) was achieved in Group II (P=0.046) and Group III (P=0.01) than in Group I. Centralizing effect of the distal femoral stem in the intramedullary canal was significantly better (P<0.05) in Group III ( 4.55% ) than in Group I (11.60%) and Group II (12.35%). Neutral alignment of femoral stem was achieved in 15% of Group I, in 90% of Group II, and in 95% of Group III. Compared to stem without centralizing device, cemented femoral stem with distal centralizer resulted in 1) significantly more centralized distal femoral stem, 2) significantly more neutrally aligned femoral stem,and 3) significantly more optimal cement mantle thickness at zone V. Compared to stem without centralizing device, cemented femoral stem with central sleeve resulted in 1) significantly more neutrally aligned femoral stem, and 2) significantly more optimal cement mantle thickness at zone VI.