Safe Optimal Tear Drop View for Spinopelvic Fixation Using a Three-Dimensional Reconstruction Model of the Pelvis.

Background: Spinopelvic fixation (SPF) has been a challenge for surgeons despite the advancements in instruments and surgical techniques. C-arm fluoroscopy-guided SPF is a widely used safe technique that utilizes the tear drop view. The tear drop view is an image of the corridor from the posterior superior iliac spine to the anterior inferior iliac spine (AIIS) of the pelvis. This study aimed to define the safe optimal tear drop view using three-dimensional reconstruction of computed tomography images. Methods: Three-dimensional reconstructions of the pelvises of 20 individuals were carried out. By rotating the reconstructed model, we simulated SPF with a cylinder representing imaginary screw. The safe optimal tear drop view was defined as the one embracing a corridor with the largest diameter with the inferior tear drop line not below the acetabular line and the lateral tear drop line medial to the AIIS. The distance between the lateral border of the tear drop and AIIS was defined as tear drop index (TDI) to estimate the degree of rotation on the plane image. Tear drop ratio (TDR), the ratio of the distance between the tear drop center and the AIIS to TDI, was also devised for more intuitive application of our simulation in a real operation. Results: All the maximum diameters and lengths were greater than 9 mm and 80 mm, respectively, which are the values of generally used screws for SPF at a TDI of 5 mm and 10 mm in both sexes. The TDRs were 3.40 ± 0.41 and 3.35 ± 0.26 in men and women, respectively, at a TDI of 5 mm. The TDRs were 2.26 ± 0.17 and 2.14 ± 0.12 in men and women, respectively, at a TDI of 10 mm. Conclusions: The safe optimal tear drop view can be obtained with a TDR of 2.5 to 3 by rounding off the measured values for intuitive application in the actual surgical field.

Reconstruction of the weight-bearing heel with nonsensate reverse sural artery flaps.

BACKGROUND: The reverse sural artery flap (RSAF) is widely used to reconstruct foot and ankle defects. Although it is commonly used in a nonsensate type, there has been controversy as to whether it provides sufficient stability and durability when applied to weight-bearing heels. The aim of this study was to evaluate patient outcomes after weight-bearing heel coverage using a nonsensate RSAF. METHODS: Twenty-three patients who underwent reconstruction surgery of the weight-bearing heel with RSAF from 2004 to 2018 in a tertiary hospital were retrospectively reviewed. All surgeries were performed without a sensate procedure. The patients' experience of pressure sore on the flap area and the ability to use normal footwear were investigated. Light touch, Semmes-Weinstein test (SWT), and two-point discrimination tests were assessed, along with postoperative wound complications. RESULTS: Heel damage etiologies included malignant tumors in 14 (61%), trauma-related in 7 (30%) and diabetic ulcers in 2 (9%) patients. Patient mean age was 58 years (range, 18-93 years) and the mean follow-up period was 57 months (range, 12-185 months). The mean size of the flap was 64.1 cm2 (range, 20-169 cm2). All flaps healed without major complications. All returned to daily living activities and 20 (86%) patients were able to use normal footwear. Of the 11 patients who had available measurement records, 8 (73%) showed a light touch sense. The mean SWT value was 4.31 (range, 3.61- 4.56). Two-point discrimination was not observed in any of the patients. Two patients had experienced superficial ulcers on the flap within a one-year postoperative period, which spontaneously healed and did not recur. No full-thickness ulcers were observed during the follow-up period. CONCLUSIONS: The results of this study suggest that patients who underwent nonsensate RSAF for the reconstruction of the heel could expect to maintain the property for stable weight-bearing without pressure sore.