The volume of the mastoid air cell system was measured in 69 patients with normal middle ears. All patients underwent axial ultrahigh-resolution computed tomography. Mastoid pneumatization was marked on each axial slice, and 3-dimensional reconstruction was performed. The volumes were measured with a volumetric algorithm. A polyethylene tubing phantom with a density similar to that of bone on computed tomography was devised. The polyethylene tubing was tied in a particular fashion so as to create interconnecting air spaces with a known volume. The phantom was scanned with the imaging parameters used for scanning the temporal bone. The air in the tubing was marked, and 3-dimensional reconstruction for the marked phantom air was performed. The volume of the interconnecting air spaces was measured and found to be identical to its known volume, thereby verifying the accuracy of the method used. The mean mastoid volume was 6.61 cm3. The smallest volume measured was 1.3 cm3, and the largest was 12.7 cm3. The importance of this technique lies in its high accuracy, ease of use, and ability to directly correlate mastoid size and clinical findings.

Blue dye performed well as a single modality for SLN biopsy. Non-identification, axillary nodal recurrence and serious allergic reactions were uncommon.

The coronoid-first surgical approach, using a suture-lasso fixation method, has technical benefits for us and showed good clinical success in our series. This is important with postero-medial rotatory instability being common in our series of TTIs. We emphasize not to miss a TTI in an apparently isolated low Mason class radial head fracture.

To analyze the factors influencing early disc height loss following lateral lumbar interbody fusion (LLIF). Overview of Literature: Postoperative disc height loss can occur naturally as a result of mechanical loading. This phenomenon is enabled by the yielding of the polyaxial screw heads and settling of the cage to the endplates. When coupled with cage subsidence, there can be significant reduction in the foraminal space which ultimately compromises the indirect decompression achieved by LLIF. Methods: Seventy-two cage levels in 37 patients aged 62±10.2 years who underwent single or multilevel LLIF for degenerative spinal conditions were selected. Their preoperative and postoperative follow-up radiographs were used to measure the anterior disc height (ADH), posterior disc height (PDH), mean disc height (MDH), disc space angle (DSA), and segmental angle. Correlations between the loss of disc height and several factors, including age, construct length, preoperative lordosis, postoperative lordosis, disc height, cage dimensions, and cage position, were analyzed. Results: We found that the lateral interbody cages significantly increased ADH, PDH, MDH, and DSA after surgery (p<0.0001). However, there was a loss of disc height over time. All postoperative disc height parameters, especially the amount of increase in MDH (r=0.413, p<0.0001) after surgery, showed a significant positive association with early disc height loss. The levels demonstrating a significant (≥25%) height loss were those that exhibited a substantial height increase (128.3%, 4.6±3.0 to 10.5±5.6 mm) postoperatively. However, the levels that showed less than 25% height loss were those that exhibited, on average, only a 57.4% height increase postoperatively. Conclusions: The greater the postoperative increase in disc height, the greater the disc height loss throughout early follow-up. Therefore, achieving an optimal disc height rather than overcorrection is an important surgical strategy to adopt when performing LLIF.

Background Orthopedic residents in our institute have the opportunity to participate in navigation-assisted spine surgery during their residency training. This paves the way for a new dimension of learning spine surgery, which the previous generation was not exposed to. To study this in detail, we conducted a cross-sectional descriptive survey among our residents to analyse their perception, understanding, and competency regarding pedicle screw application using spinal navigation. Methods We selected orthopedic residents (n = 20) who had completed 3 years of training that included at least one rotation (4–6 months) in our spine division. They were asked to respond to a four-part questionnaire that included general and Likert scale-based questions. The first two parts dealt with various parameters regarding spinal navigation and free-hand technique for applying pedicle screws. The third part dealt with residents' opinion regarding the advantages and disadvantages of spinal navigation. The final part was an objective analysis of residents' ability to identify the pedicle screw entry points in selected segments. Results We found that our residents were better trained to apply pedicle screws using spinal navigation. The mean Likert scale score for perception regarding their competency to apply pedicle screws using spinal navigation was 3.65 ± 0.81, compared to only 2.8 ± 0.77 when using the free-hand technique. All residents agreed that spinal navigation is an excellent teaching tool with higher accuracy and greater utility in anatomically critical cases. However, 35% of the residents were not able to identify the entry points correctly in the given segments. Conclusions All selected residents were perceived to be competent to apply pedicle screws using spinal navigation. However, some of them were not able to identify the entry points correctly, probably due to overreliance on spinal navigation. Therefore, we encourage residents to concentrate on surface anatomy and tactile feedback rather than completely relying on the navigation display monitor during every screw placement. In addition, incorporating cadaveric and saw bone workshops as a part of teaching program can enhance better understanding of surgical anatomy.