Mismatch between Augmented Reality Navigation Images and Actual Location of a Cauda Equina Tumor:A Case Report.

BACKGROUND: Augmented reality navigation is the one of the navigation technologies that allows computer-generated virtual images to be projected onto a real-world environment. Augmented reality navigation can be used in spinal tumor surgery. However, it is unknown if there are any pitfalls when using this technique. CASE PRESENTATION: The patient in this report underwent complete resection of a cauda equina tumor at the L2-L3 level using microscope-based augmented reality navigation. Although the registration error of navigation was <1 mm, we found a discrepancy between the augmented reality navigation images and the actual location of the tumor, which we have called "navigation mismatch". This mismatch, which was caused by the mobility of the spinal tumor in the dura mater, seems to be one of the pitfalls of augmented reality navigation for spinal tumors. CONCLUSIONS: Combined use of intraoperative ultrasound and augmented reality navigation seems advisable in such cases. J. Med. Invest. 71 : 174-176, February, 2024.

Return-to-play outcomes after full-endoscopic spine surgery under local anesthesia in professional baseball players: Comparison by timing of surgery.

BACKGROUND: Full-endoscopic spine surgery via a transforaminal approach (TF-FESS) is minimally invasive and could help athletes quickly return to play. When treating professional athletes, we have to consider their season schedule. In this study, we investigated the characteristics of Japanese professional baseball players who underwent TF-FESS and examine how the timing of surgery influenced their postoperative course. METHODS: Ten players who underwent TF-FESS (discectomy, foraminoplasty, or thermal annuloplasty according to their diagnosis) under local anesthesia were analyzed. Multilevel surgeries were performed at the same time in patients with lesions at multiple levels. The patients were divided into three groups according to timing of surgery (pre/during/post-season). Time to complete return to play and duration of official game loss were compared between the three groups. RESULTS: All players (100 %) could return to their original level of professional play after FESS surgery. Seven of the 10 patients underwent two-level surgery. The mean time until complete return to play was 4.6 months (range, 2-8 months) and the mean duration of game loss was 1.5 months (range, 0-4 months). The mean duration of game loss was shorter in the post-season group than in the other groups (0.9 vs 2,4 months), and 4 of 6 patients in the post-season group did not miss any games. CONCLUSIONS: TF-FESS is a good technique for achieving a quick return to play in professional baseball players. In particular, surgery performed during the post-season could allow players to return to play after adequate rehabilitation with no game loss.

Advantages of Full-endoscopic Trans-Kambin's Triangle Lumbar Interbody Fusion for Degenerative Spondylolisthesis: Illustrative Cases.

Various approaches to lumbar interbody fusion have been described. The usefulness of full-endoscopic trans-Kambin's triangle lumbar interbody fusion has recently been reported. This technique has several advantages in patients with degenerative spondylolisthesis, including the ability to improve symptoms without decompression surgery. Moreover, given that the entire procedure is performed percutaneously, it can be performed without increasing the operation time or surgical invasiveness, even in obese patients. In this article, we discuss these advantages and illustrate them with representative cases.

Evaluation of segmental mobility in patients with lumbar spondylolisthesis : A comparison of images from standing flexion-extension and standing/supine slippage.

PURPOSE: To evaluate segmental mobility with degenerative lumbar spondylolisthesis (DLS), upright lateral flexion-extension radiographs (FE) are widely used. However, some authors have described that a combination of lateral radiographs in the standing position and supine sagittal image (SS) reveal more segmental mobility than FE. The purpose of this study was to investigate the optimal method for evaluating segmental mobility with DLS. METHODS: We included 92 consecutive Japanese patients diagnosed with DLS. Sagittal translation (ST) determined by FE and SS were compared. Pathological instability was defined as ST more than 8% of the upper vertebra. Patients were divided into those diagnosed with pathological instability in FE (PI-FE) and those diagnosed with SS (PI-SS), and lumbar lordosis (LL) in the standing position in each group were compared. RESULTS: ST in FE was significantly greater than in SS. Of 92 patients, 31 had pathological instability in FE or SS ; 17 patients had PI-FE, and 10 patients had PI-SS. LL in the standing position in PI-FE was significantly smaller than in PI-SS. CONCLUSIONS: ST in FE was greater than that in SS, contrary to previous studies' reports on Caucasians. Since Japanese individuals have smaller LL than Caucasians, FE tends to reveal more segmental mobility than SS. J. Med. Invest. 70 : 135-139, February, 2023.

Comparison Between Treatment of Bicondylar Tibial Plateau Fractures With or Without Posterolateral Fragments Using Posteromedial and Anterolateral Approaches.

Background: The best surgical approach for treating posterolateral fragments in tibial plateau fractures remains controversial. This study compared the radiological and functional outcomes of bicondylar tibial plateau fractures, with or without posterolateral fragments, treated using the same posteromedial and anterolateral approaches. Methods: Twenty-six patients with 27 bicondylar tibial plateau fractures were surgically treated between June 2006 and February 2020. The patients were divided into two groups: with posterolateral fragments (PL group) and without posterolateral fragments (non-PL group). All patients were treated with the combined posteromedial and anterolateral approach. Knee function was assessed using the Lysholm score and by measuring the range of motion (ROM). Fracture reduction was assessed using Rasmussen radiological scores. Results: Fifteen bicondylar fractures were classified in the PL group and 12 in the non-PL group. No significant difference was found in the ROM and Lysholm scores between the groups. No significant difference was noted in Rasmussen radiological scores between the groups. Conclusion: Using the combined posteromedial and anterolateral approach, bicondylar tibial plateau fractures with posterolateral fragments achieved reasonable functional and radiological outcomes compared to those without a posterolateral fragment. This combined approach enabled an adequate visualization and reduction of posterolateral fragments. These standard approaches may be adequate for most bicondylar tibial plateau fractures with posterolateral fragments.

A juvenile recurrent elbow dislocation resolved by internal fixation of the avulsed lateral chondral fragment after ossification: A case report.

We report a case of juvenile recurrent posterior dislocation of the elbow with an avulsed cartilage fragment. The avulsed fragment from the lateral condyle gradually became larger since the initial dislocation, and was ossified. After three dislocations, the avulsed bone fragment was secured with screws and the anterior capsule was repaired. Elbow function recovered without any dislocation after the avulsion fracture healed. Open reduction and internal fixation of the avulsed fragment is worth trying at first for juvenile recurrent elbow dislocation, even in chronic cases.

Relevance between Schmorl's Node and Lumbar Intervertebral Disc Degeneration Quantified with Magnetic Resonance Imaging T2 Mapping in Chronic Low Back Pain.

STUDY DESIGN: Cross-sectional study. PURPOSE: The purpose of this study was to elucidate the relevance among Schmorl's node (SN), chronic low back pain (CLBP), and intervertebral disc degeneration (IVDD) with the use of magnetic resonance imaging T2 mapping. OVERVIEW OF LITERATURE: SN may be combined with CLBP and/or IVDD; however, their relationship has not been determined to date. METHODS: A total of 105 subjects were included (48 men and 57 women; mean age, 63.2±2.7 years; range, 22-84 years). We analyzed five functional spinal unit levels (L1-S1) and evaluated the T2 values of the anterior annulus fibrosus (AF), nucleus pulposus, and posterior AF. We compared the low back pain (LBP) Visual Analog Scale (VAS) scores and the T2 values in each decade with or without SN. RESULTS: There were no remarkable differences in SN prevalence rate regarding age decade or gender. SNs were more prevalent in the upper 2 levels (70.3%). LBP VAS scores with and without SN were 64.7±4.3 mm and 61.9±2.8 mm, respectively, with no significant differences between the groups (p=0.62). The T2 values of anterior AF with SN were significantly lower than those without SN in patients in their 50s, 60s, 70s, and 80s (p<0.01). CONCLUSIONS: SN presence is not itself a risk factor for CLBP; however, it indicates IVDD of the anterior AF in subjects with SN who are ≥50 years old.

Tibial Plafond Attachment of the Posterior-Inferior Tibiofibular Ligament: A Cadaveric Study.

BACKGROUND: Some recent studies have reported the role of the posterior malleolus as an attachment of the posterior-inferior tibiofibular ligament (PITFL) and suggested that even a small fragment should be fixed. However, there are few anatomic studies of the tibial plafond attachment of the PITFL. METHODS: Seven Thiel-embalmed ankles were obtained. The margin of the distal tibial joint surface and the attachments of the superficial fiber of the PITFL (sPITFL) and the deep fiber (dPITFL) were identified. In the frontal view, the percentages of the attachments of the sPITFL and dPITFL of the mediolateral dimension of the posterior tibial plafond were measured. In the lateral view, the line that started from the proximal margin of the attachment of the sPITFL and parallel to the tibial axis was drawn, and the distance between that line and the posterior edge of the joint surface was measured (AP distance of the sPITFL). Then, the percentage of the AP distance of the sPITFL of the joint surface in the anteroposterior dimension of the tibial plafond was measured. RESULTS: In the frontal view, the mediolateral distance of the attachment of the sPITFL was 5.0 mm, and that of the dPITFL was 19.5 mm. The percentage of the attachment of the sPITFL on the tibial plafond was 20.6%, and that of the dPITFL was 78.2%. In the lateral view, the average AP distance of the sPITFL was 0.5 mm, and the percentage in the anteroposterior dimension of the tibial plafond was 1.7%. CONCLUSION: The PITFL was attached to less than 10% of the anteroposterior dimension of the tibial plafond in most ankles. Conversely, the PITFL attached widely in the mediolateral dimension. CLINICAL RELEVANCE: This study suggests that the size of the posterior malleolar fragment in the mediolateral dimension could help estimate how much of the PITFL attaches to the fragment which may have implications for ankle stability.

Do We Have Adequate Flexion-extension Radiographs for Evaluating Instability in Patients With Lumbar Spondylolisthesis?

STUDY DESIGN: A retrospective cohort study of consecutive patients. OBJECTIVE: To investigate whether adequate flexion-extension was acquired in standard functional radiographs in lumbar spondylolisthesis. SUMMARY OF BACKGROUND DATA: In lumbar spondylolisthesis, flexion-extension radiographs taken in the standing position are most commonly used to evaluate spinal instability. However, these functional radiographs occasionally depend on the patient's effort and cooperation, they can provide different results. METHODS: This study included 92 consecutive patients diagnosed with L4-5 degenerative lumbar spondylolisthesis. We analyzed the flexion-extension radiographs taken with the patient being led by the hand (LH) and those taken without LH (NLH). Sagittal translation (ST), segmental angulation (SA), posterior opening (PO), and lumbar lordosis (LL) were measured on functional radiographs taken in both tests. Then, ST, SA, PO, detection rate of instability, and LL observed in LH were compared with those observed in NLH. Furthermore, the correlation of the difference was evaluated between ST, lumbar angulation, and LL. RESULTS: A relative value of ST was 9.5% ±â€Š4.3% in LH and 5.6% ±â€Š3.3% in NLH, which differed significantly (P < 0.001). SA and PO were also significantly greater in LH than in NLH. The detection rate of instability was 71.7% in LH and 30.4% in NLH (P < 0.001). LL measurement on flexion showed 17.6°â€Š±â€Š13.5° in LH and 28.2°â€Š±â€Š12.2° in NLH, which differed significantly (P < 0.001). However, no significant difference was found in LL on extension between LH and NLH. There was a moderate correlation between the difference of ST, SA, PO, and LL on flexion. CONCLUSION: Flexion with physical assistance was useful for the detection of abnormal lumbar mobility. Taking radiation exposure into consideration, physical assistance such as using a table in front of a patient could lead the similar evaluation of the segmental instability. LEVEL OF EVIDENCE: 2.

[Radiotherapy for Alleviation of Paraparesis due to Leptomeningeal and Cauda Equina Metastasis of HER2-Positive Breast Cancer: A Case Report].

Leptomeningeal metastasis is a rare entity and its diagnosis is often difficult. Moreover, evidence-based therapeutic strategies have not yet been established. A 52-year-old woman presented with high fever and was diagnosed with bacterial meningitis at first examination;although her fever was alleviated, she experienced motor weakness in both of her lower extremities. Ga scintigraphy highlighted the hot-spot areas of the disease in the cranial bone. She was then transferred to our department. Open biopsy of the skull showed metastasis of the cancer. Chest CT results indicated right breast cancer and Gd-DTPA imaging showed obvious enhancement of the pia mater around the conus medullaris and cauda equina. However, cerebrospinal fluid(CSF)cytological examination did not show the presence of any positive cells;consequently, mastectomy was performed in the thoracic surgical department. The severity of paraparesis and pain in her legs increased;however, repeat MRI 1 month later showed no evidence of any change. Therefore, we performed biopsy of the cauda equina and arachnoid lesions. The pathological diagnosis was metastasis of breast cancer with positive human epidermal growth factor receptor 2(HER2)immunological staining. The results of a repeat cytological examination of the CSF during the surgery were negative. Local radiotherapy(25 Gy/5 Fr)as a monotherapy was selected for the patient, because her family did not approve of the combination of radiotherapy and chemotherapy. The severity of both paraparesis and limb pain decreased immediately after the radiotherapy.