Short-term clinical results of bicruciate-retaining total knee arthroplasty using personalized alignment.

BACKGROUND: Bicruciate-retaining (BCR) prosthesis has been introduced to recreate normal knee movement by preserving both the anterior and posterior cruciate ligaments. However, the use of BCR total knee arthroplasty (TKA) is still debatable because of several disappointing reports. We have been performing BCR TKAs with personalized alignment (PA). This study aimed to reveal the limb alignment and soft tissue balance of FA-BCR TKAs and compare the clinical outcomes of FA-BCR TKAs with those of unicompartmental knee arthroplasty (UKA). METHODS: Fifty BCR TKAs and 58 UKAs were included in this study. The joint component gaps of BCR TKA were evaluated intraoperatively and the postoperative hip-knee-ankle (HKA) angle, medial proximal tibial angle (MPTA), and lateral distal femoral angle (LDFA) were measured using full-length standing radiography. The short-term clinical outcomes of BCR TKAs were compared with those of UKA using the scoring system of 2011 Knee Society Scoring (KSS) and the knee injury and osteoarthritis outcome score (KOOS) at an average of 2 years postoperatively (1-4yeras). RESULTS: The coronal alignment values of PA-BCR TKA were as follows: HKA angle, 177.9° ± 2.3°; MPTA, 85.4° ± 1.9°; and LDFA, 87.5° ± 1.9°. The joint component gaps at flexion angles of 10°, 30°, 60°, and 90° were 11.1 ± 1.2, 10.9 ± 1.4, 10.7 ± 1.3, and 11.2 ± 1.4 mm for the medial compartment and 12.9 ± 1.5, 12.6 ± 1.8, 12.5 ± 1.8 and 12.5 ± 1.7 mm for the lateral compartment, respectively. The patient expectation score and maximum extension angle of PA-BCR TKA were significantly better than those of UKAs. CONCLUSIONS: The short-term clinical outcomes of PA-BCR TKA were comparable or a slightly superior to those of UKAs.

Chronic spontaneous epidural hematoma in the lumbar spine with cauda equina syndrome and severe vertebral scalloping mimicking a spinal tumor: a case report.

BACKGROUND: Chronic spinal epidural hematomas (SEHs) are rare clinical entities. SEH with vertebral scalloping is extremely rare, with only a few cases having been reported to date. We report a unique case of spontaneous chronic SEH in the lumbar spine with severe vertebral scalloping mimicking an epidural tumor. CASE PRESENTATION: A 71-year-old man presented with a 2-month history of lumbar pain and a 3-week history of paresthesia and pain in the right lower extremity, hypesthesia in the perineal and perianal regions, and bladder dysfunction. Computed tomography following myelography revealed an epidural mass lesion on the right side that compressed the dural sac and was associated with severe bony scalloping on the posterior wall of the L4 vertebral body. Magnetic resonance imaging (MRI) on T1- and T2-weighted images revealed a space-occupying lesion with heterogeneous intensity, and T1-gadolinium images showed an intralesional heterogeneous enhancement effect. A tumoral lesion in the spinal canal was suspected, based on preoperative imaging; therefore, a total spinal tumor resection was planned. Intraoperative findings revealed that the brownish lesion adhered to the dura and epidural tissues in the spinal canal, and the space-occupying mass in the scalloped cavity of the posterior wall of the L4 vertebra was encapsulated in red-brownish soft tissues. The lesion was totally resected in a piecemeal fashion, and pathological examination revealed a mixture of tissues that contained a relatively new hematoma with hemoglobin, as well as an obsolete hematoma with hemosiderin and amyloid deposits. The mass was diagnosed as a chronic epidural hematoma with recurrent hemorrhage. The postoperative course was uneventful, and the preoperative neurological symptoms immediately improved. CONCLUSIONS: The preoperative diagnosis of chronic SEHs is challenging, as MRI results may not be conclusive, particularly in patients with scalloping of bony structures. Thus, chronic SEHs should be considered as a differential diagnosis in cases of suspected tumoral lesions in the spinal canal. To the best of our knowledge, this is the first reported case of acute exacerbation of chronic SEH with cauda equina syndrome and severe vertebral scalloping.

Inter-examiner reliability in identifying lumbar paraspinal muscle atrophy by lumbar paraspinal muscle atrophy index, a novel parameter.

[Purpose] To evaluate the inter-examiner reliability of our novel parameter, the lumbar paraspinal muscle atrophy index, in identifying the lumbar paravertebral muscle atrophy. [Participants and Methods] The study group consisted of 225 adults, with a mean age of 64.7 (range, 21-89) years, who underwent posterior lumbar spinal surgery for degenerative spinal disease at our hospital between July 2013 and June 2017. Preoperative axial T2-weighted magnetic resonance images were used to evaluate the lumbar paraspinal muscle atrophy index and observe the presence or absence of severe lumbar paraspinal muscle atrophy. The lumbar paraspinal muscle atrophy index was calculated at each intervertebral level, from L1-2 through L4-5, once by two examiners, and the Cohen's kappa statistic was used to calculate the inter-examiner agreement of the classification of the presence or absence of atrophy at each level. [Results] The agreement was high (kappa, 0.79-0.88) for the lumbar paraspinal muscle atrophy index at all levels, except at the L3-4 level (kappa, 0.49). The lower kappa statistic at L3-4 likely reflects the unique morphological characteristics at this level. [Conclusion] The lumbar paraspinal muscle atrophy index is a new, simple, easy-to-use, and sufficiently reliable parameter to identify lumbar paraspinal atrophy.

Risk factors for deep surgical site infection following posterior instrumented fusion for degenerative diseases in the thoracic and/or lumbar spine: a multicenter, observational cohort study of 2913 consecutive cases.

PURPOSE: Surgical site infection (SSI) is one of the most devastating complications following spinal instrumented fusion surgeries because it may lead to a significant increase in morbidity, mortality, and poor clinical outcomes. Identifying the risk factors for SSI can help in developing strategies to reduce its occurrence. However, data on the risk factors for SSI in degenerative diseases are limited. This study aimed to identify risk factors for deep SSI following posterior instrumented fusion for degenerative diseases in the thoracic and/or lumbar spine in adult patients. METHODS: This was a multicenter, observational cohort study conducted at 10 study hospitals between July 2010 and June 2015. The subjects were consecutive adult patients who underwent posterior instrumented fusion surgery for degenerative diseases in the thoracic and/or lumbar spine and developed SSI. Detailed patient-specific and procedure-specific potential risk variables were prospectively recorded using a standardized data collection chart and retrospectively reviewed. RESULTS: Of the 2913 enrolled patients, 35 developed postoperative deep SSI (1.2%). Multivariable regression analysis identified three independent risk factors: male sex (P = 0.002) and American Society of Anesthesiologists (ASA) score of ≥ 3 (P = 0.003) as patient-specific risk factors, and operation including the thoracic spine (P = 0.018) as a procedure-specific risk factor. CONCLUSION: Thoracic spinal surgery, an ASA score of ≥ 3, and male sex were risk factors for deep SSI after routine thoracolumbar instrumented fusion surgeries for degenerative diseases. Awareness of these risk factors can enable surgeons to develop a more appropriate management plan and provide better patient counseling.

Inter-rater reliability between two examiners with different professional roles in the evaluation of fat infiltration in the lumbar paraspinal muscles using magnetic resonance imaging.

[Purpose] To clarify the inter-rater reliability of the evaluation criteria for paraspinal muscle fat infiltration on magnetic resonance images between two examiners with different professional roles in interdisciplinary physical therapy teams. [Participants and Methods] In this retrospective study, we reviewed the clinical data of 225 patients with degenerative lumbar diseases who underwent posterior lumbar surgery at our hospital. A physical therapist and a spinal surgeon visually quantified fat infiltration of the multifidus muscles at the level of L4/5 on the preoperative magnetic resonance images of the patients using Kjaer's criteria (Grade 0: 0-10%, Grade 1: 10-50%, and Grade 2: >50%). We used the kappa coefficient to assess inter-rater reliability. [Results] The participants included 142 males and 83 females (mean age, 64.7 years; range, 21-89 years). The number of patients with grades 0/1/2 were 50/160/15, respectively, for examiner 1; and 59/155/11, respectively, for examiner 2. The kappa coefficient was 0.69, indicating a substantial agreement. [Conclusion] Our study, which is the first to assess the inter-rater reliability of Kjaer's criteria between examiners with different medical occupations, revealed that these criteria could be a reliable tool for evaluating fat infiltration in the multifidus muscles and sharing information between interdisciplinary physical therapy teams.

Temporal hemiarthroplasty for distal femoral osteosarcoma in early childhood: a case report.

BACKGROUND: Prosthetic reconstruction for distal femoral osteosarcoma is challenging for younger children. We herein report a successful case of limb-sparing surgery for a younger patient with distal femoral osteosarcoma requiring osteo-articular resection. CASE PRESENTATION: A 5-year-old girl with high-grade conventional osteosarcoma in the left distal femur underwent a series of surgeries. After three cycles of neoadjuvant chemotherapy, limb-salvage surgery was planned because femoral rotationplasty had been refused. At 6 years and 2 months old, distal femoral resection and temporary spacer insertion using a 7-mm-diameter intramedullary nail and molded polymethylmethacrylate was performed. At 7 years and 8 months old, secondary surgery was performed because the first spacer had been dislocated and the residual femur became atrophic. The distal end of the residual femur was removed by 1 cm, but the periosteum and induced membrane around polymethylmethacrylate was preserved. In order to stabilize the spacer against the tibia, a custom-made ceramic spacer with a smooth straight 8-mm-diameter stem was utilized. The bone-spacer junction was fixed with polymethylmethacrylate and then covered with the preserved periosteum and induced membrane. After surgery, the bone atrophy improved. At 9 years and 7 months old, the second spacer was removed because it had loosened, and the knee joint was reconstructed using a custom-made growing femoral prosthesis with a curved porous 8.5-mm-diameter stem. Cancellous bone tips from the proximal tibia were grafted around the bone-prosthesis junction underneath the induced membrane. At 10 years and 5 months old, the patient was able to walk unsupported and a radiograph showed further thickening of the cortex of the residual femur without any stress shielding. Although having 5 cm of limb length discrepancy, the patient and her mother were satisfied with the function. The MSTS score was 24 out of 30 points. Repeated limb length extensions are planned. CONCLUSIONS: This case report provides an example of limb-salvage surgery after distal femoral resection in a small child. The use of a temporary spacer utilizing partial cementation and preservation of the periosteum and induced membrane appears to afford a viable limb-salvage option after distal femoral resection for younger children.

Analysis of the Infiltrative Features of Chordoma: The Relationship Between Micro-Skip Metastasis and Postoperative Outcomes.

BACKGROUND: Chordomas are very rare primary malignant bone tumors that arise commonly from the sacrum (50-60%) and clivus (25-35%). Chordomas have a high rate of recurrence. The authors confirmed a unique histologic infiltration pattern of chordomas that resembles a skip-metastatic lesion in normal tissue around tumor, which they named "micro-skip metastasis." This study aimed to examine the correlations between the clinicopathologic features of chordomas, including micro-skip metastasis, and the clinical outcomes, including overall survival, local recurrence-free survival, and distant metastasis-free survival. METHODS: The study analyzed histopathologic and clinical data from patients with sacral chordomas who underwent en bloc resection from July 1991 through July 2014. Cases with a minimum follow-up period shorter than 20 months after resection were excluded. Kaplan-Meier survival analyses with log-rank tests were performed for overall survival, metastasis-free survival, and recurrence-free survival. RESULTS: The study retrospectively reviewed 40 patients. The mean follow-up period was 98.2 months (range 22-297 months). The local recurrence rate was 41.3%. Micro-skip metastases, observed in 17 patients (42.5%), were associated with a significantly increased risk of local recurrence (p = 0.023) but not with overall survival or distant metastasis-free survival. Poorer overall survival was associated with histologic vascular invasion (p = 0.030) and a greater maximum tumor diameter (p = 0.050). CONCLUSIONS: The presence of micro-skip metastasis was associated with a higher rate of local recurrence. The maximum tumor diameter and the presence of histologic vascular invasion were associated with poorer overall survival.

Cross-cultural adaptation and validation of the Japanese version of the Toronto Extremity Salvage Score (TESS) for patients with malignant musculoskeletal tumors in the upper extremities.

BACKGROUND: The Toronto Extremity Salvage Score (TESS) is a widely used disease-specific patient-completed questionnaire for the assessment of physical function in patients with musculoskeletal tumors; however, there had not been the validated Japanese version of the TESS. The aim of this study was to validate the Japanese version of the TESS in patients with musculoskeletal tumors in the upper extremity. METHODS: After developing a Japanese version of the TESS, the questionnaire was administered to 53 patients to examine its reliability and validity in comparison with the Musculoskeletal Tumor Society (MSTS) scoring system and Short Form-36 (SF-36). RESULTS: Test-retest reliability with intraclass correlation coefficient (0.93) and internal consistency with Cronbach's alpha (0.90) were excellent. Factor analysis showed that the construct structure consisted of 3-item clusters, and the Akaike Information Criterion network also demonstrated that the items could be divided into 3 domains according to their content. The TESS strongly correlated with the MSTS rating scale (r = 0.750; P < 0.001) and the SF-36 physical functioning scale (r = 0.684; P < 0.001). However, as expected, the TESS had low correlations with the SF-36 mental health and role-emotional subscales and the MSTS scoring system manual dexterity domain. CONCLUSIONS: Our study suggests that the TESS is a reliable and valid instrument to measure patient-reported physical functioning in patients with upper extremity sarcoma.

The effect of an external hip joint stabiliser on gait function after surgery for tumours located around the circumference of the pelvis: analysis of seven cases of internal hemipelvectomy or proximal femur resection.

PURPOSE: Limb-sparing resection of malignant pelvic tumours provides the opportunity for patients to obtain better post-operative mobility. However, because few studies have examined in detail the gait function of patients following pelvic tumour resection, the factors affecting gait performance remain to be clarified. Here, with the laboratory-based computer-assisted gait analysis, we evaluated these patients' gait objectively and the impact of a hip-stabilising supporter on gait improvement was simultaneously examined. METHODS: Three-dimensional gait analysis was performed to obtain cross-sectional data for seven post-operative patients (mean age, 42.7 years; range, 20-61 years) who underwent various types of resection, including P1/4 internal hemipelvectomy (IH), P1/2/3 IH, and proximal femur resection with prosthetic reconstruction. To assess the immediate effects of a hip joint stabiliser, we instructed subjects to walk at their self-selected preferred speed and compared gait parameters with and without use of the hip stabiliser. RESULTS: At baseline, the average walking speed was 0.75 m/s (95% CI 0.53-0.97). As shown by the intra-subject comparison, the hip stabiliser increased walking speed in all but one subject, increasing both temporal and spatial parameters. Ground reaction force of operated limbs increased for some subjects, while step length increased on at least one side in all subjects. CONCLUSIONS: Improvement in the gait parameters is indicative of better control provided by the external hip stabiliser over the affected limb. Moreover, our findings show the potential of a biomechanical approach to improve gait function following pelvic tumour resection.

Cross-cultural adaptation and validation of the Japanese version of the Toronto Extremity Salvage Score (TESS) for patients with malignant musculoskeletal tumors in the lower extremities.

BACKGROUND: Before this work a Japanese version of the Toronto Extremity Salvage Score (TESS), a disease-specific patient-completed questionnaire widely used to assess the physical function of patients with musculoskeletal tumors, had not been developed. The purpose of this study was cross-cultural adaptation and validation of the English-language version of the TESS to facilitate international comparisons of treatment results. METHODS: The TESS was translated into Japanese, back-translated into English, and reviewed by a committee to develop a consensus Japanese version of the TESS. One hundred and two patients were assessed by use of this Japanese version to examine its reliability and validity. RESULTS: Test-retest reliability and internal consistency determined by using the intraclass correlation coefficient (0.941) and Cronbach's alpha test (0.978), respectively, were excellent. Factor analysis showed that the structure consisted of a three-item cluster; the Akaike information criterion (AIC) network also demonstrated that the items could be divided into three domains in accordance with their content. The Japanese version of the TESS correlated with the Musculoskeletal Tumor Society rating scale (r = 0.811; P < 0.001) and the Short Form-36 physical component summary (r = 0.785; P < 0.001). CONCLUSIONS: Our study suggested that the Japanese version of the TESS is a reliable and valid instrument for measuring patient-reported functional outcome for patients with lower extremity sarcoma, and that it enables international comparisons of treatment results. The spatial association of each item demonstrated by using the AIC network also suggested that the underlying structure of the TESS reflected its coverage of a wide range of physical functions.

Differences in the Demographics and Clinical Characteristics between the Ossification of the Posterior Longitudinal Ligament and Ossification of the Ligamentum Flavum in Patients Who Underwent Thoracic Spinal Surgery for Compressive Myelopathy.

Ossification of the posterior longitudinal ligament (OPLL) and ossification of the ligamentum flavum (OLF) are related diseases associated with the ossification of spinal ligaments that can occasionally lead to thoracic myelopathy. We retrospectively analyzed the clinical data of 34 consecutive patients who underwent thoracic spinal surgeries for OPLL and/or OLF at our hospital between July 2010 and June 2022, and statistically compared data between patients with thoracic OPLL (TOPLL; n = 12) and those with thoracic OLF (TOLF; n = 22). The mean age of the TOPLL group was significantly lower than that of the TOLF group (53.7 vs. 68.4 years). The TOPLL group exhibited a greater female predominance than the TOLF group (58.3% vs. 18.2%). The median body mass index of the TOPLL group was significantly higher than that of the TOLF group (33.0 vs. 26.0 kg/m2). Patients with TOPLL significantly required instrumented fusion and repetitive surgical intervention more than those with TOLF (83.3% vs. 9.1%; 50.0% vs. 0.0%). Although neurological deterioration just after the intervention was more common in patients with TOPLL (41.7% vs. 4.6%), no difference was observed in thoracic Japanese Orthopaedic Association score and recovery rate in the chronic phase between TOPLL and TOLF. The TOPLL group had a younger onset, female dominance, and a greater degree of obesity when compared with the TOLF group. The surgery for TOPLL is challenging, considering that it requires long-range decompression and fusion, subsequent operations, careful management, and long-term follow-up, when compared to TOLF, which necessitates only simple decompression.

Association of Preoperative Osteoporotic Vertebral Compression Fractures with Muscle Atrophy in Lumbar Spinal Stenosis: A Retrospective Cohort Study.

Objectives: Osteoporotic vertebral compression fractures (OVCFs) are common in older individuals and lead to pain, spinal deformities, and limited mobility. Paraspinal muscle function correlates with fracture severity, and this association may be more significant in patients with lumbar spinal stenosis (LSS). However, studies on the effects of OVCFs are lacking. This study aimed to investigate the relationship between OVCFs, fat infiltration, and muscle atrophy in patients with LSS. Methods: This study included 177 patients with preoperative LSS, of whom 16 had OVCFs and 161 did not. Lumbar lordosis angle, fat infiltration, and paraspinal muscle atrophy were evaluated in these patients. Information on patient characteristics such as smoking, diabetes, hemodialysis, steroid use, American Society of Anesthesiologists score, and bladder or bowel dysfunction were obtained from medical records. Logistic regression analysis was conducted to identify factors independently associated with OVCF. Results: Patients in the OVCF group were significantly older (P=0.006) than those without fractures, and a higher proportion of the OVCF group showed muscle atrophy (P=0.034). Significant variables and those with moderate effect sizes were included in the logistic regression analysis. Muscle atrophy (P=0.028) was independently associated with OVCF. Conclusions: Muscle atrophy was associated with preoperative OVCFs in patients with LSS. Identifying OVCFs in these patients may underscore the importance of tailored treatment and rehabilitation strategies for the paraspinal muscles.

Postoperative Measurement of the Retropharyngeal Space Predicts the Risk of Dysphagia After Anterior Cervical Diskectomy and Fusion.

BACKGROUND AND OBJECTIVES: Postoperative dysphagia is a common complication of anterior cervical diskectomy and fusion (ACDF), although its pathophysiology remains poorly understood. Patients with severe dysphagia may suffer from serious complications such as aspiration pneumonia, in addition to difficulty with oral intake or malnutrition; therefore, a prompt indicator for postoperative management would be helpful. We quantitatively evaluated the retropharyngeal space (RS) after ACDF and investigated its association with postoperative dysphagia. METHODS: This multicenter retrospective study analyzed the clinical data of 82 consecutive patients who underwent ACDF. The anteroposterior distance (APD) of the RS was measured at the C2 level using a lateral radiographic view on postoperative day 1. Postoperative dysphagia was subjectively assessed using the Bazaz-Yoo Dysphagia Severity Scale. We statistically evaluated the association between the APD of the RS and postoperative dysphagia. RESULTS: The mean APD of the RS in all 82 patients was 3.6 mm preoperatively and significantly increased to 8.2 mm postoperatively (P < .0001). Twenty-two patients (26.8%) had postoperative dysphagia. Multivariable analysis revealed that the postoperative APD was associated with postoperative dysphagia (odds ratio 1.27, 95% CI 1.10-1.50, P = .0007). The receiver operating characteristic curve (area under the curve 0.70, 95% CI 0.58-0.83) demonstrated that the postoperative APD of the RS cutoff value was 6.1 mm, with a sensitivity of 100% and a specificity of 35%. With this cutoff value, the positive and negative predictive values for postoperative dysphagia were 36% and 100%, respectively. CONCLUSION: Our data demonstrate that a value of 6.1 mm for the APD of the RS is an effective indicator for dysphagia after ACDF, which contributes to optimizing the patient management in the acute postoperative period.

Figure-4 Patient Positioning Increases Medial Meniscus Extrusion on Ultrasound in Patients With Posterior Medial Meniscus Root Tears of the Knee.

Purpose: To compare the degree of medial meniscal extrusion (MME) between knees with medial meniscus posterior root tear (MMPRT) and degenerative tears of the medial meniscus using ultrasonography (US) in different limb positions and to identify the findings characteristic of MMPRT. Methods: The study group comprised 25 subjects with MMPRT (group RT), 25 subjects with degenerative medial meniscal tears (group D), and 25 knees with no abnormalities of the medial meniscus (MM) on magnetic resonance imaging (MRI) (group C) whose age was ≥40 years. MME was evaluated using US in the supine, figure-4, feet-dangling, and standing positions. The MME was evaluated by the actual measurement values and the relative values to the MME in the supine position. The differences in the MME among the 3 groups in each limb position were analyzed using one-way analysis of variance. P < .05 was considered significant. Results: The actual MME values were largest in group RT in all 4 limb positions. When changing the limb position from the supine to the figure-4, the actual MME increased from 3.8 ± 0.8 mm to 5.5 ± 1.3 mm in group RT, whereas it decreased from 3.4 ± 1.1 mm to 1.8 ± 1.2 mm in group D, showing the most significant difference in MME of the figure-4 position between the 2 groups (P < .001). In group RT, 88% of knees had the maximum MME in the figure-4 position. In group D, 60% of knees had the maximum MME in the standing position and only 2 knees (8%) had the maximum MME in the figure-4 position. Conclusions: The increase in MME from the supine to the figure-4 position was a characteristic finding of MMPRT but not degenerative tears. Level of Evidence: Level III, case-control study.

Metastatic renal cell carcinoma of the lumbar spine with long posterior instrumented fusion and repetitive dislodgement of the set screws of the S2 alar-iliac screw.

Background: S2 alar-iliac screws (S2AIS) are widely used to anchor the pelvis to a lumbar fusion. Here, we report a patient who experienced repetitive dislodgement of the set screws of the S2AIS following a posterior instrumented fusion. Case Description: A 68-year-old male presented with an L3 metastasis and L2-L3 subluxation attributed to renal cell cancer. Following an L2-L5 posterior decompression and T9-pelvic fusion utilizing bilateral S2AIS fixation, the set screws of the S2AIS repeatedly dislodged, requiring two additional operations. The final surgery required multiple anchors to the ilium and provided adequate fixation until the patient's expiration. Conclusion: The set screw fixing force was weaker than the fixing force of the S2AIS; multiple iliac anchors effectively salvaged this condition.

Atypical clinical and radiological presentations of lumbar spinal tuberculosis mimicking a spinal tumor: A case report.

INTRODUCTION: Tuberculosis (TB) is an important infectious disease worldwide. Classical spinal TB has specific radiological findings involving adjacent vertebral bodies with destruction of the intervertebral disc and involvement of paravertebral soft tissues with cold abscess formation. However, a few cases not exhibiting the radiological characteristics of TB spondylitis have been reported. We report a rare case of lumbar spinal TB with atypical clinical and radiological presentations that was difficult to differentiate from a malignant spinal tumor. PATIENT CONCERNS: A 21-year-old man, who had immigrated to Japan from the Philippines 5 years ago, without a significant medical history, presented with back pain lasting 1 month and progression of gait disturbance 2 weeks prior to presentation. DIAGNOSIS: Laboratory tests showed normal blood cell counts and normal value of C-reactive protein levels. Preoperative imaging studies indicated a possible spinal tumor. However, histopathologic findings of the epidural soft tissues at the first surgery led to the diagnosis of spinal mycobacterial infection. The diagnosis of spinal TB was confirmed by a positive culture of Mycobacterium tuberculosis obtained at the second surgery. INTERVENTIONS: Given the progressive nature of neurologic deterioration, instead of needle biopsy, we proceeded with surgical intervention 8 days after admission; simultaneous neural decompression and open biopsy. Histological findings of the excised epidural soft tissues led to the diagnosis of spinal mycobacterial infection. We performed the second surgery involving additional resection of epidural soft tissues for further dural decompression and to obtain specimens for mycobacterial culture. Immediately after the second surgery, the patient commenced combination therapy with anti-tuberculous drugs. OUTCOMES: The patient demonstrated significant recovery of motor function in the lower extremities, and was able to run at 2 months after the second surgery. The epidural granulomas completely disappeared on magnetic resonance imaging 3 months postoperatively. CONCLUSION: Atypical clinical and radiological presentations of spinal TB present a challenge for appropriate diagnosis and early treatment. Even in developed countries where there are very few spinal TB patients, clinicians should be aware that spinal TB is an important differential diagnosis, especially in elderly patients or patients coming from countries with a middle-high prevalence of TB.

Ultraearly Hematoma Evacuation (<12 Hours) Associated with Better Functional Outcome in Patients with Symptomatic Spontaneous Spinal Epidural Hematoma.

BACKGROUND: Early decompressive surgery within 24 hours improves the functional outcome of patients with traumatic spinal cord injury; however, little is known about the effect of early surgery for spontaneous spinal epidural hematoma (SSEH). In this study, we aimed to investigate the effectiveness of ultraearly hematoma evacuation (<12 hours) for SSEH. METHODS: Patients with SSEH treated with surgical hematoma evacuation at our institution between January 2000 and July 2021 were retrospectively analyzed. Neurologic function was evaluated using the American Spinal Injury Association Impairment Scale (AIS). AIS grades A-C were defined as severe, and grades D and E as mild. AIS grades D and E at the final follow-up were considered favorable outcomes. Preoperative status and postoperative treatment results were compared between patients who had hematoma evacuation within 12 hours of onset and those who underwent surgery after 12 hours. RESULTS: Twenty-five consecutive patients were included in the analysis. Preoperatively, 23 patients (92.0%) had severe AIS. Fourteen (56.0%) patients underwent early surgery. At the final follow-up, 21 patients (84.0%) achieved favorable outcomes. Patients treated with ultraearly surgery had significantly better outcomes (100% vs. 63.6%, P = 0.03). Additionally, the time from onset to surgery was significantly shorter in patients with AIS improvement by 2 or more grades than that in patients with AIS improvement of 1 or less (median 8 hours vs. 14 hours, P = 0.0001). CONCLUSIONS: Ultraearly surgery within 12 hours for SSEH was associated with better functional outcomes.

Rare Case of BCOR::CCNB3 Sarcoma of Bone.

BACKGROUND BCOR: CCNB3 sarcoma is a rare mesenchymal tumor that was formerly included in the undifferentiated/unclassified sarcoma group and was recently reclassified as one of undifferentiated small round cell sarcomas with a genetically distinct subtype in the WHO 2020 classification. Because of its rarity, still not much is known, especially about its clinical features. CASE REPORT A 15-year-old boy presented with almost 1-year intermittent thigh pain. On the first visit, a pathologic fracture of the femur and a big mass expanding through the femoral cortex with lobular shape and homogenous appearance were recognized on radiography and magnetic resonance imaging. Plain radiography, which was taken 6 months before at a local clinic, showed an expansion and thickening of the right proximal femoral shaft. Biopsy specimen of the lesion revealed a proliferation of round to spindle tumor cells with diffuse and strong immunohistochemical nuclear positivity for BCOR and CCNB3. Under the diagnosis of BCOR::CCNB3 sarcoma of the femur, a chemotherapy based on a protocol of Ewing sarcoma, followed by a wide resection and total femoral replacement surgery, were conducted. The effect of chemotherapy was favorable, showing no microscopic residual tumor. Although postoperative chemotherapy was not completed because of a minor infection detected on the surgical site, the patient was doing well, without any recurrence, for 26 months. CONCLUSIONS BCOR: CCNB3 sarcoma of the bone is a quite rare tumor with much lower incidence than Ewing sarcoma. Notable clinical characteristics of the current case were a 1-year-long symptomatic period and homogenous appearance on MRI.

Risk Factor Analysis for Fat Infiltration in the Lumbar Paraspinal Muscles in Patients With Lumbar Degenerative Diseases.

INTRODUCTION: This study aimed to investigate factors related to fat infiltration in patients with lumbar degenerative diseases (lumbar disc herniation and/or spinal stenosis), examining a wide range of potential risk variables. MATERIALS AND METHODS: We studied consecutive adult patients who underwent posterior lumbar spinal surgery for degenerative diseases at our hospital between July 2013 and June 2017. Preoperative magnetic resonance imaging was used to evaluate the presence or absence of fat infiltration at the level of the L4-5 lumbar paraspinal muscles using Kjaer's evaluation method. Patients without fat infiltration (0%-10%) were rated as grade 0, grade 1 for moderate fat infiltration (10%-50%), and grade 2 for severe fat infiltration (>50%). Patients were then divided into two groups: Group A (without fat infiltration, grade 0) and Group B (with fat infiltration, grade 1 or 2). Detailed patient clinical data were collected and analyzed. RESULTS: A total of 205 consecutive patients were enrolled; 54 (26.3%) patients were assigned to Group A and 151 (73.7%) to Group B. Logistic regression analysis revealed two independent risk factors for fat infiltration of the lumbar paraspinal muscles: female sex and older age (P < .001). DISCUSSION: Fat infiltration of the lumbar paraspinal muscles is reported to be associated with the development of pain and dysfunction of the lumbar region and postoperative complications of spinal instrumented fusion surgery. To the best of our knowledge, no previous studies have identified female sex and older age as independent risk factors for fat infiltration in the lumbar paraspinal muscles using multivariate analysis. CONCLUSIONS: Female sex and older age were independent risk factors for fat infiltration in the lumbar paraspinal muscles. The results of the current study may provide useful information for the study of preventive measures for fat infiltration.

Acute femoral osteomyelitis due to hypermucoviscous Klebsiella pneumoniae.

Hypervirulent hypermucoviscous Klebsiella pneumoniae strains have emerged as clinically important pathogens causing invasive infections. K. pneumoniae osteomyelitis is uncommon in adult patients, and may mimic bone tumors on presentation. We report a patient with left rectus femoris muscle abscess and acute osteomyelitis of the left femur due to hypermucoviscous K. pneumoniae with negative blood culture, who was initially thought to have left thigh tumor. The patient's infection resolved with surgical drainage and debridement and intravenous and antibiotic therapy.