Patellar Tendon Imbrication

Background: Patella alta is a common cause of patellar instability. Patellar tendon imbrication is a successful surgery addressing the deformity by shortening the patellar tendon without necessitating an osteotomy. Indications: Symptomatic patella alta causing patellar instability in both skeletally immature and adult patients. Technique Description: The patellar tendon is exposed, and levels of imbrication as determined preoperatively by radiographic measurements are outlined on the tendon with a marking pen. A third line is then made proximal to the level of dissection that is half the distance of the lengthening. From the distal marking, a flap of tendon, the anterior half, is elevated by sharp dissection using a fresh No. 15 blade proximal to the predetermined level. Next, “redundancy-reducing” 2-0 vicryl sutures are placed and left untied by entering at the proximal marking, passing deep to the tendon, and emerging at the middle of the intact posterior section of tendon, followed by placement of 3 structural #2 Ethibond/Ti-Cron horizontal sutures into the patellar tendon that will create and maintain the imbrication. These sutures are then tied proximally while applying downward pressure to the patella to avoid tying under tension. Next, the “redundancy-reducing” sutures are tied thus imbricating the redundant posterior section of tendon. In a “pants over vest” fashion, the distal end of the anterior section of isolated tendon is repaired with ‘‘0’’ absorbable suture. The knee is then flexed beyond 90° to assess competence of the suture lines and to assess the need for quadriceps lengthening. Results: Radiographic shortening is maintained at a minimum of 2 years on 27 patients/32 knees. There were no complications directly related to the technique. Discussion/Conclusion: Patellar tendon imbrication is a safe and effective procedure to correct patella alta in the setting of lateral patellar instability. On average, the technique allowed 1 cm of patellar tendon shortening and maintained the correction at a minimum 2-year follow-up. In the skeletally immature patient, this technique allows correction of patella alta by avoidance of a tibial tuberosity osteotomy.

Comparison of strength and depth cut with scalpel on porcine gingival tissues

The composition of the gums confers some physical characteristics that make it resistant to mechanical stimulation. The objective of the study was to compare the difference of the utilized forces when performing cuts in the anterior and posterior sections of porcine gingival tissue, measuring the depth of the tissue. A comparative descriptive study was performed with a non-probability convenience sampling, sectioned pig mandibles were used. The experimental trials were performed with an EZ-S SHIMADZU texture analyzer. All of the samples were submitted to a vertical shear force, thus identified the force level used to perform the incision and its depth. the necessary force to perform a cut in porcine gingival tissue was evaluated, comparing the posterior section (39.3571 Newton and 2.160 mm) and with the anterior ( 37.8424 newton and 1.747 mm), just as the depth of said cut, showing a statistical difference on the depth, (p=0.022 p< 0.59); regarding the force, no statistically significant difference was found. In the analyzed samples where the shear force in the posterior and anterior section were compared, no difference was found in both groups; as for the cut depth, this was greater in the posterior section than in the anterior.

Quantitative Assessment of the Accuracy of Real-Time Virtual Sonography for Liver Surgery

Background. Real-time virtual sonography (RVS) is a navigation system for liver surgery. In this study, the degree of misalignment of intraoperative RVS images with computed tomographic (CT) images was measured. Methods. Between December 2014 and July 2015, intraoperative RVS was performed in a total of 33 patients undergoing liver surgery. Reconstructed CT images, rendered like intraoperative ultrasonographic (IOUS) images, were adjusted with the IOUS images and visualized side by side. The degree of misalignment between the reconstructed CT images and IOUS images was measured at anterior section, posterior section, and left liver in each patient. Furthermore, the time required for the adjustment was measured as the “adjustment time.” Results. The degree of misalignment between the images could potentially be measured for a total of 96 points in the 33 patients. Of these, the actual measurement could not be conducted for 35 points due to poor visualization of the intrahepatic vasculature (n = 20) or to a large misalignment that hampered continuation of further adjustment (n = 15). The median degree of misalignment was 9.8 mm (range = 2.4-37.6 mm) in the right anterior section, 9.8 mm (range = 2.7-71.5 mm) in the right posterior section, and 9.5 mm (range = 0.9-37.6 mm) in the left liver. The median adjustment time was 105 seconds (range = 51-245 seconds). Conclusions. Although some misalignment occurred, it might be acceptable for selected situations. Further investigation is needed to reduce the frequency of adjustment failure.