Effect of hyperdry amniotic membrane in preventing tendon adhesion in a rabbit model.

BACKGROUND: No anti-adhesive materials are currently in clinical use for orthopaedic surgery. We developed a hyperdry amniotic membrane (HD-AM) for easy storage and transplantation as amniotic membrane. The purpose of this study was to examine the application of HD-AM to reduce peritendinous adhesions without impairing tendon healing. METHODS: We randomly divided 3 digits (2nd, 3rd, and 4th digits) from each rabbit into three groups: a tendon repair group; a tendon repair with HD-AM group (HD-AM group); and a control group (cast only). The effects of HD-AM on peritendinous adhesions and tendon healing were examined using microscopic, histological, and mechanical analyses in a rabbit flexor digitorum profundus tendon model. RESULTS: Adhesions on macroscopic evaluation of the tendon repair site were significantly smaller in the HD-AM group than in the tendon repair group. Little adhesion formation or foreign body reactions were seen by on histologic evaluation in the HD-AM group. Range of motion following tendon repair was significantly better in the HD-AM group than in the tendon repair group. Maximal tensile strength required to pull the tendon from the site of adhesion was significantly smaller in the HD-AM group than in the tendon repair group. As for tendon repair site, no significant difference was seen between the tendon repair and HD-AM groups. CONCLUSIONS: HD-AM prevented peritendinous adhesion macroscopically, pathologically, and mechanically without impairing the sutured tendon. HD-AM has already been clinically applied in neurosurgery, ophthalmology, and otolaryngology, and clinical application as an anti-adhesive materials may be achieved in the future.

Evaluation of complete and incomplete subscapularis tendon tear on preoperative magnetic resonance imaging.

BACKGROUND: This study aims to evaluate the significance of preoperative magnetic resonance imaging findings to predict subscapularis tear confirmed at arthroscopic surgery. METHODS: Sixty-four consecutive shoulders that underwent preoperative magnetic resonance imaging examination and arthroscopic shoulder operations were retrospectively reviewed. Under arthroscopic examination, complete subscapularis tear was defined as a full-thickness tear and incomplete subscapularis tear as tendon detachment larger than 5 mm from the insertion on the joint side. RESULTS: In arthroscopic findings, they were included 11 shoulders with complete subscapularis tear, 13 with incomplete subscapularis tear, and the remaining 28 shoulders without subscapularis tear. Subscapularis discontinuity by axial magnetic resonance imaging had the highest sensitivity and specificity in detecting complete subscapularis tear compared with other magnetic resonance imaging findings. Long head biceps subluxation or dislocation showed significantly higher prevalence in the complete and incomplete subscapularis tear groups than in the group with no tear. Incomplete subscapularis tear groups had a higher incidence of superior subscapularis recess fluid, and this fluid was present in all the shoulders with incomplete subscapularis tear. CONCLUSIONS: The presence of subscapularis discontinuity is useful for diagnosis of complete subscapularis tear. In addition, in cases of incomplete subscapularis tear, the presence of superior subscapularis recess fluid had 100% sensitivity. Thus, this finding may be a characteristic diagnosis of subscapularis tear including incomplete tear.

Evaluating various radiographic methods of shoulder joint damage in patients with rheumatoid arthritis receiving biological disease-modifying antirheumatic drugs.

OBJECTIVES: This study aims to clarify shoulder joint damage in rheumatoid arthritis patients receiving biological disease-modifying antirheumatic drugs (bDMARDs) and the relationship between joint damage and clinical factors. PATIENTS AND METHODS: In this retrospective study conducted between April 2005 and December 2008, 36 shoulders in 19 patients (2 males, 17 females; mean age: 58.9 years; range 42 to 75 years) were evaluated at baseline and two years after the initiation of bDMARD therapy with infliximab (n=14) or etanercept (n=5). Standard anteroposterior radiographs of the shoulder joints were taken at baseline and two years after institution of biological therapy. Structural damage in the shoulder joints was assessed using the Larsen scoring method, the medial displacement index (MDI), and the upward migration index (UMI). RESULTS: There was a significant correlation between MDI, UMI, and Larsen grade before biological therapy. Univariate analysis revealed that the disease activity score 28-count erythrocyte sedimentation rate (ESR) at baseline (odds ratio [OR]: 4.298) was associated with progression of MDI. But multivariate logistic regression revealed that there was no association with the progression of MDI. Univariate analysis revealed that ESR at baseline (OR: 0.967) and matrix metalloproteinase-3 (MMP-3) at baseline (OR: 0.996) were associated with the progression of UMI. Multivariate logistic regression revealed that MMP-3 at baseline (OR: 0.994) was independently associated with the progression of UMI. CONCLUSION: Medial displacement index and UMI correlated with the Larsen grade of the shoulder joint strongly and moderately, respectively. This study suggests that MDI and UMI may help to evaluate radiographic progression of damage in shoulder joints in patients on bDMARDs, which is difficult to detect using the Larsen grade.

Relationship between the physician-based clinical scale for foot and ankle surgery and patient-reported outcomes in patients with long-standing rheumatoid arthritis: Results from a multicenter prospective observational cohort study.

OBJECTIVES: To validate and establish targets for the physician-based clinical scale for foot surgery in rheumatoid arthritis (RA) patients based on patient-reported outcomes from a multicenter prospective cohort. METHODS: We collected data on demographics, values from the RA foot and ankle scale by the Japanese Society for Surgery of the Foot (JSSF-RA), and patient-reported outcomes (PROs) including the Health Assessment Questionnaire Disability Index (HAQ-DI) before (baseline) and 6 and 12 months after joint surgery. Target values for JSSF-RA were determined according to the lower limit of the 95% CI of JSSF-RA in patients with HAQ-DI ≤0.5 after adjusting for age and sex. We used multiple linear regression analysis to examine potential predictors of JSSF-RA target achievement at baseline. RESULTS: Cross-sectional analysis was conducted on data from 417 cases. The JSSF-RA target for foot and ankle surgery was set at 74 according to the JSSF-RA value corresponding to HAQ-DI ≤0.5 (mean 77.6, 95% CI: 74.3-80.9). Longitudinal analysis of patients who underwent foot surgery (N = 59) determined target cut-off values of 1.188 and 65 for HAQ-DI and JSSF-RA at baseline, respectively, as being predictive for achieving JSSF-RA ≥74 after surgery. CONCLUSIONS: A JSSF-RA value of 74 represents an important target for patients with RA who have undergone foot surgery. In order to achieve this target, the timing of the surgery should be considered in the treatment of established RA patients.

Sacroiliac joint variation associated with diffuse idiopathic skeletal hyperostosis.

BACKGROUND: Diffuse idiopathic skeletal hyperostosis (DISH) is characterized by the ossification of vertebral bodies and peripheral entheses. However, variations in sacroiliac (SI) joint change in patients with DISH have not been fully clarified. The purpose of this study was to evaluate SI joint variation in patients with DISH in comparison with a non-DISH population. METHODS: A total of 342 SI joints in 171 patients (DISH+, n = 86; DISH-, n = 85) who had undergone lumbar spine surgery were analyzed by computed tomography examination. SI joint variations were classified into four types: Type 1, normal or tiny peripheral bone irregularity; Type 2, subchondral bone sclerosis and osteophytes formation; Type 3, vacuum phenomenon; and Type 4, bridging osteophyte and bony fusion. The type of bridging osteophyte in SI joints and the prevalence of ossification in each spinal segment from C1 to SI joint were also examined. RESULTS: The most common SI joint variation in the DISH+ group was bony fusion (Type 4), with 71.6% exhibiting anterior paraarticular bridging. On the other hand, SI joint vacuum phenomenon (Type 3) was the most frequent change (57.1%) in the DISH- group. The middle to lower thoracic spine and SI joints were highly affected in DISH and caused bony ankylosis. CONCLUSIONS: Anterior paraarticular bridging was the most common type of SI joint change in patients with DISH who underwent lumbar spine surgery. The present results regarding variations of SI joint changes in DISH should help understand the etiology of DISH.

Increase of the Serum FGF-23 in Ossification of the Posterior Longitudinal Ligament.

STUDY DESIGN: Case-control study. OBJECTIVES: To determine the possible pathogenesis of ossification of the posterior longitudinal ligament (OPLL) in regard to the serum concentration of fibroblast growth factor 23 (FGF-23). METHODS: The study included 95 patients with OPLL and a control group of 73 age- and sex-matched volunteers. The serum concentrations of FGF-23, creatinine (Cre), alkaline phosphatase, calcium (Ca), inorganic phosphate (Pi), and hypersensitive C-reactive protein (hs-CRP) were analyzed from blood samples, and Cre, Ca, Pi, and tubular reabsorption of phosphate were measured using urine samples. We evaluated the severity of ossified spinal lesions in patients with OPLL according to the ossification index (the OP index and the OS index). Data was compared between the OPLL and control group and between the OPLL progression and no progression group. RESULTS: Serum FGF-23 and hs-CRP were higher, and serum Pi was lower in patients with OPLL than in the controls. There was a positive correlation between FGF-23 and hs-CRP and a negative correlation between serum Pi and the OS index; however, the correlations were very weak. Overall, 31.7% of patients had progression of OPLL during follow-up. FGF-23 and hs-CRP were higher in the progression group than in the no progression group. CONCLUSIONS: These results might indicate that FGF-23 and hs-CRP are positive markers for OPLL. Phosphate metabolism via FGF-23 might be a target for future study on the pathogenesis of OPLL.

Clinical outcome and ultrasonographic evaluation of treatment using polyglycolic acid-collagen tube for chronic neuropathic pain after peripheral nerve injury.

BACKGROUND: A novel polyglycolic acid (PGA)-collagen tube has been available in Japan since March 2013, and the development of high-resolution ultrasonography has recently allowed detailed evaluation of nerves. The purpose of this study was to report the clinical outcomes and evaluations of in-vivo changes under high-resolution ultrasonography for treatment using PGA-collagen tube for painful chronic nerve injury. METHODS: Four patients underwent surgical management of peripheral nerve neuroma, with nerve defects after neuroma resection reconstructed using PGA-collagen tube. Mean duration of follow-up was 30 months. Patients were surveyed to determine visual analog scale scores for pain before surgery and at final follow-up. At final follow-up, sensory function was evaluated using the Semmes-Weinstein test, static 2-point discrimination (2PD), and moving 2PD. Furthermore, we performed ultrasonography for all patients every 1 month after surgery. RESULTS: In all cases, resting pain, radicular pain, and dysesthesia were improved immediately after the operation and remained improved until the last follow-up. At the time of final follow-up, the Semmes-Weinstein test was red in 2 cases and blue in 2 cases. Mean static 2PD was 15.5 ± 5.3 mm and mean moving 2PD was 11.5 ± 5.3 mm. Ultrasonography revealed that the PGA outer wall had disappeared by 3 months postoperatively, and a hypoechoic linear shadow bridged the proximal and distal stumps. Swelling of the junction between nerve and nerve conduits was revealed at 4 months after surgery and remained until last follow-up. CONCLUSIONS: All patients were very satisfied with pain relief, but recovery of sensory function was insufficient. Ultrasonographic evaluation after using PGA-collagen tube for painful chronic peripheral nerve injury was useful for observing in-vivo changes. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Differential proteome analysis in adolescent idiopathic scoliosis patients with thoracolumbar/lumbar curvatures.

BACKGROUND: Although the pathogenesis of adolescent idiopathic scoliosis (AIS) remains unclear, there are little evidences of the pathogenesis in patients with thoracolumbar/lumbar AIS. The purpose of this study was to identify proteins or proteomes that may be causally related to the pathogenesis of AIS with structured thoracolumbar/lumbar curvature using two-dimensional fluorescence difference gel electrophoresis (2D-DIGE). METHODS: A total of 20 control volunteers and 61 AIS in patients with thoracolumbar/lumbar curvature were included. First, the plasma samples of each five AIS with pure thoracolumbar/lumbar curvature and control samples were subjected to 2D-DIGE analysis. Protein spots that were expressed differently by the AIS and control groups were selected and identified by nanoscale liquid chromatography-tandem mass spectrometry (nanoLC-MS/MS) analysis. To characterize the differently-expressed proteins in AIS patients, we performed functional pathway analysis using the Protein ANalysis THrough Evolutionary Relationships (PANTHER) system. Additionally, the proteins were compared between control and AIS using western blotting. Lastly, prospectively collected 15 control and 41 AIS with thoracolumbar/lumbar curvature samples were compared to the differentially expressed proteins. RESULTS: A total of 3862 ± 137 spots were detected, of which 11 spots met the criteria when compared with controls. Nine proteins were identified by nanoLC-MS/MS. Functional analysis showed the association of the proteins in AIS patients with blood coagulation using the PANTHER system. Of the proteins, vitamin D binding protein (DBP) significantly correlated with Cobb angle in thoracolumbar/lumbar curvatures. DBP expression of the prospectively collected AIS samples were significantly higher than those of controls (P < 0.05). CONCLUSIONS: This study suggests that DBP and several coagulation-related proteins may play a role in the pathogenesis of AIS. DBP appears to be a marker of severity of AIS with thoracolumbar/lumbar curvature.

Low-dose eribulin reduces lung metastasis of osteosarcoma in vitro and in vivo.

Lung metastasis markedly reduces the prognosis of osteosarcoma. Moreover, there is no effective treatment for lung metastasis, and a new treatment strategy for the treatment of osteosarcoma lung metastasis is required. Therefore, in this study, we investigated the suppressive effect of the microtubule inhibitor eribulin mesylate (eribulin) on lung metastasis of osteosarcoma. At concentrations >proliferation IC50, eribulin induced cell cycle arrest and apoptosis in a metastatic osteosarcoma cell line, LM8. However, at concentrations

Radial Dislocation of Extensor Tendon Over the Metacarpophalangeal Joint of the Thumb due to Cerebral Hemorrhage: A Case Report.

We report a rare case of radial dislocation of the extensor tendon over the metacarpophalangeal (MCP) joint of the thumb. Ulnar dislocation has been reported, but previous reports have not mentioned radial dislocation of the extensor tendon in the thumb. Radial dislocation of the extensor tendon of the thumb gradually progressed after cerebral hemorrhage and the patient could not extend MCP joint of the thumb. To resolve difficulty in extending the MCP joint, surgical centralization of the extensor tendon and partial resection of the flexor pollicis brevis (FPB) and abductor pollicis brevis (APB) insertions was performed. The patient recovered function of thumb extensors.

Differential rod contouring on thoracolumbar/lumbar curvature in patients with adolescent idiopathic scoliosis: An analysis with intraoperative acquisition of three-dimensional imaging.

BACKGROUND: Differential rod contouring (DRC) is useful for periapical vertebral derotation and decreasing rib hump in patients with thoracic adolescent idiopathic scoliosis (AIS). However, it is unknown whether DRC in the thoracolumbar/lumbar spine also contributes to derotation. We assessed the contributions of rod contouring and of DRC to the reduction of apical axial vertebral body rotation in patients with AIS with thoracolumbar/lumbar curvatures. METHODS: Forty-five (Lenke type 3 or 4, 17; Lenke type 5 or 6, 28) were analyzed for the contribution of DRC to thoracolumbar/lumbar spinal derotation. Rod contouring was assessed by comparing the preinsertion x-ray with the post-operative CT images. Intraoperative C-arm fluoroscopic scans of the periapical vertebrae of the thoracolumbar/lumbar curve of the scoliosis (135 vertebrae) were taken post-rod rotation (RR) and post-DRC in all patients. Three-dimensional images were automatically reconstructed from the taken x-ray images. The angle of vertebral body rotation in these apical vertebrae was measured, and the contribution of DRC to apical vertebral body derotation and rib hump index (RHi) for lumbar prominence was analyzed. RESULTS: The pre-implantation convex rod curvatures of both Lenke 3/4 and 5/6 groups decreased after surgery. The mean further reductions in vertebral rotation with post-RR DRC were 3.7° for Lenke 3/4 and 4.4° for Lenke 5/6 (P < 0.01). Both changes in apical vertebral rotation and in RHi for evaluating lumbar prominence were significantly correlated with the difference between concave and convex rod curvature in preimplantation. Vertebral derotation was significantly higher in curves with a difference >20° (P < 0.05). CONCLUSIONS: DRC following rod rotation contributed substantial additional benefit to reducing vertebral rotation and decreasing lumbar prominence in thoracolumbar/lumbar scoliosis.

Three-Dimensional Computed Tomography Analysis of Spinal Canal Length Increase After Surgery for Adolescent Idiopathic Scoliosis: A Multicenter Study.

BACKGROUND: The most severe complication after surgery for adolescent idiopathic scoliosis is spinal cord injury. There is a relationship between corrective surgery and subsequent elongation of the spinal canal. We sought to investigate which factors are involved in this phenomenon. METHODS: Seventy-seven patients with adolescent idiopathic scoliosis (49 with Lenke type 1 and 28 with type 2) who underwent spinal correction surgery were included. The mean patient age at surgery was 14.2 years (range, 11 to 20 years). The spines of all patients were fused within the range of T2 to L2, and computed tomography (CT) data were retrospectively collected. We measured the preoperative and postoperative lengths of the spinal canal from T2 to L2 using 3-dimensional (3D) CT-based imaging software. We also examined the association between the change in T2-L2 spinal canal length and the radiographic parameters. RESULTS: The length of the spinal canal from T2 to L2 was increased by a mean of 8.5 mm in the patients with Lenke type 1, 12.7 mm in those with type 2, and 10.1 mm overall. Elongation was positively associated with the preoperative main thoracic Cobb angle in both the type-1 group (R = 0.43, p < 0.005) and the type-2 group (R = 0.77, p < 0.000001). The greatest elongation was observed in the periapical vertebral levels of the main thoracic curves. CONCLUSIONS: Corrective surgery for adolescent idiopathic scoliosis elongated the spinal canal. The preoperative proximal, main thoracic, and thoracolumbar/lumbar Cobb angles are moderate predictors of postoperative spinal canal length after scoliosis surgery. CLINICAL RELEVANCE: It is important to understand how much the spinal canal is elongated after surgery to lessen the risk of intraoperative and postoperative neurological complications.

Clinical Impact of Ossification of the Posterior Longitudinal Ligament Progression After Cervical Laminoplasty.

STUDY DESIGN: This is a retrospective study. OBJECTIVES: (1) To analyze the incidence of second surgery after initial laminoplasty for ossification of the posterior longitudinal ligament (OPLL) due to disease progression, (2) to examine factors associated with poor surgical outcome. SUMMARY OF BACKGROUND DATA: Neurological deterioration after laminoplasty is frequently encountered due to OPLL progression. PATIENTS AND METHODS: Of 201 OPLL patients treated by laminoplasty at a single-institution, the 153 monitored for >3 years postsurgery were included in this analysis. Neurological findings were graded by the Japanese Orthopaedic Association (JOA) score. We retrospectively examined the incidence of second surgery due to OPLL progression. We also evaluated the clinical characteristics and the surgical outcomes after second operation to identify potential risk factors for poor outcome. RESULTS: Eight patients required a second surgery due to OPLL progression. Neurological recovery was achieved in 5 of these patients, whereas 3 exhibited continued dysfunction. Patients with poor recovery showed kyphotic changes of spinal alignment and high-intensity regions in the spinal cord on T2-weighted magnetic resonance images (T2-MRI). CONCLUSIONS: Only a small fraction of OPLL patients required a second surgery due to OPLL progression. Recovery was poor in those with clear high-intensity T2-MRI signals in the spinal cord.

Wide-Awake Flexor Pollicis Longus Tendon Reconstruction with Evaluation of the Active Voluntary Contraction of the Ruptured Muscle-Tendon.

The purpose of this study was to investigate the clinical outcome of the wide-awake tendon reconstruction for chronic rupture of the flexor pollicis longus tendon with evaluation of the voluntary active contraction distance of the ruptured musculotendinous unit. Eleven consecutive patients underwent tendon reconstruction under wide-awake surgery. If the total of the passive distraction distance and the active contraction distance of the ruptured flexor pollicis longus musculotendinous unit was greater than 30 mm, tendon grafting was performed. If not, tendon transfer was performed using the fourth flexor digitorum superficialis. Patients were evaluated with total active motion before surgery, during surgery, and in final follow-up and subjectively surveyed with quick Disabilities of the Arm, Shoulder and Hand scores. The final outcomes of tendon grafting and of tendon transfer were compared. Tendon grafting was performed in four patients, and tendon transfer was performed in seven patients. The final follow-up total active motion was 84.3 ± 12.7 percent in the tendon transfer group and 80.7 ± 10.2 percent in the tendon grafting group. There were no significant differences between the two groups in the final follow-up total active motion percentage and quick Disabilities of the Arm, Shoulder and Hand scores. The functional outcomes of both tendon grafting and tendon transfer were acceptable based on evaluating the active contraction distance and passive distraction distance of the ruptured musculotendinous unit during wide-awake surgery. Evaluating these distances may be a useful index to assess the ruptured musculotendinous unit. The greatest advantage of the wide-awake tendon reconstruction is that surgeons can evaluate the ruptured musculotendinous unit and measure total active motion during surgery while adjusting suture tension. CLINICAL QUESTION/LEVEL OF EVIDENCE:: Therapeutic, IV.

The effect of multiple lesions in patients with ossification of the posterior longitudinal ligament of the cervical spine.

PURPOSE: Ossification of the posterior longitudinal ligament of the cervical spine (cervical OPLL) is associated with the lesions at the thoracic and/or lumbar spine. Multiple spinal lesions cause additional neurological deficit, affecting the outcomes of cervical laminoplasty. This study aimed to clarify the effect of multiple lesions on the outcomes of cervical laminoplasty and to compare the results with data from patients without them. METHODS: From April 1981 to October 2015, 201 patients underwent laminoplasty for cervical OPLL; however, 167 patients were followed for >2 years. Twenty-four patients underwent additional surgery for multiple lesions due to spinal stenosis. The pathologies of the lesions were assessed. The patients were divided into two groups: the thoracic and thoraco-lumbar group (T-group: 8 patients) and the lumbar group (L-group: 16 patients). One-hundred patients without an additional surgery served as the control group. The maximum Japanese Orthopaedic Association (JOA) score and the most recent score for recovery was compared between the multiple and control groups. RESULTS: The maximum score and recovery rate and the score and recovery rate at the last follow-up in the multiple group were lower than those in the control group. There was no significant difference in the postoperative JOA score and recovery rate between the T-group and the L-group. CONCLUSIONS: Neurological recovery in patients with multiple lesions was poorer than in those without lesions. Therefore, special attention should be paid to cervical OPLL with multiple spinal lesions.

Target setting for lower limb joint surgery using the Timed Up and Go test in patients with rheumatoid arthritis: A prospective cohort study.

OBJECTIVE: This prospective observational cohort study aimed to set targets for lower limb joint surgery based on the Timed Up and Go test (TUG), an objective functional outcome measure, in patients with established rheumatoid arthritis (RA). METHODS: We validated TUG as an outcome measure of lower limb joint surgery and compared it with changes in patient-reported outcomes, including the Health Assessment Questionnaire Disability Index (HAQ-DI) and European Quality of life scale with five dimensions (EQ-5D). Changes in these outcomes were compared by performed surgery and by achievement of the minimal clinically important difference (MCID) for EQ-5D using univariate analysis of variance. Associations between TUG and HAQ remission (HAQ-DI ≤0.5) were determined using logistic regression analysis. Cut-off values of TUG at baseline and 6 months after surgery for HAQ remission were determined using receiver operating characteristic curves. RESULTS: A total of 126 patients were analyzed. Mean age, HAQ-DI, and TUG were 65.4 years, 1.036, and 12.8 seconds, respectively. After surgery, patients showed improvements in TUG as well as HAQ-DI. TUG at 6 months after surgery was significantly associated with HAQ remission (adjusted OR: 0.78; 95% CI: 0.65-0.93). TUG cut-off values at baseline and 6 months after surgery for achieving HAQ remission were 12.1 and 8.8 seconds, respectively. Significant improvements in TUG (∆TUG, 3.7 seconds) were associated with achievement of the MCID for EQ-5D (≥0.05) at 6 months after surgery. CONCLUSION: Timed Up and Go test is a useful tool for assessing the outcome of lower limb joint surgery in RA patients. We propose that TUG ≤9 seconds could be an objective target for achieving good physical function after lower limb joint surgery.

Extraskeletal osteosarcoma arising in the subcutaneous tissue of the lower leg: A case report and literature review.

Extraskeletal osteosarcoma (ESOS) is a rare soft tissue sarcoma accounting for 1-2% of all soft tissue sarcomas. ESOS originating in the superficial (cutaneous-subcutaneous) tissue is extremely rare, and only 17 cases with subcutaneous ESOS have been reported in detail to date. The aim of the present study was to report an additional case of subcutaneous ESOS of the lower leg and review previous reports of subcutaneous ESOS, focusing on the clinical characteristics, including the MIB-1 labeling index, treatment methods and outcomes. A 79-year-old healthy man presented with a 3-year history of a painful, slowly growing mass in his right lower leg that measured ~5 cm in greatest dimension. Excisional biopsy was performed, and ESOS was diagnosed based on the histopathological findings. A wide resection was performed when local recurrence developed. Six months after the wide resection, lung metastasis was detected. Considering the patient's age, stereotactic radiotherapy was performed without chemotherapy. The patient showed no evidence of local recurrence or new distant metastases for 2 years after the second surgery. We herein present this case of subcutaneous ESOS and review the previous 17 reported cases of subcutaneous ESOS. The 5-year survival rate of patients with subcutaneous ESOS was 78.6%, which was better compared with that of ESOS cases arising in deep soft tissue. Therefore, patients with subcutaneous ESOS may have a better prognosis compared with those with deep-seated ESOS, although the mean MIB-1 labeling index of subcutaneous ESOS was 24%.

Primary cauda equina lymphoma diagnosed by nerve biopsy: A case report and literature review.

Primary cauda equina lymphoma (CEL) is a rare malignant tumor among various neoplasms that affects the cauda equina nerve roots. The present case report described the case of a 65-year-old man who presented with cauda equina syndrome with progressive motor palsy in the legs and gait disturbance over the last 5 months. Magnetic resonance (MR) images showed enlargement of the cauda equina occupying the dural sac from the L1-S1 level with isointensity to the spinal cord signal on both T1- and T2-weighted imaging. Enhancement of the cauda equina was seen on contrast MR images. On F-18 2-fluoro-2-deoxy-glucose positron emission tomography examination, diffuse accumulation of 2-fluoro-2-deoxy-glucose was observed in the cauda equina with a maximum standardized uptake value of 4.9. Based on elevation of soluble interleukin 2 receptor in cerebrospinal fluid and a biopsy of the enlarging cauda equina, a diagnosis of CEL of the diffuse large B-cell type was made. The present case report provided a detailed case discussion and a review of the available literature on this rare entity, focusing on clinical characteristics and imaging of primary CEL.

Clinical and imaging characteristics in patients undergoing surgery for lumbar epidural lipomatosis.

BACKGROUND: Lumbar epidural lipomatosis (LEL) is characterized by abnormal accumulation of unencapsulated adipose tissue in the spinal epidural space. Such accumulation compresses the dural sac and nerve roots, and results in various neurological findings. However, the pathophysiology of LEL remains unclear. This study examined the associations between imaging and clinical findings in detail, and investigated the mechanisms underlying symptom onset by measuring intraoperative epidural pressures in LEL. METHODS: Sixteen patients (all men; mean age, 68.8 years) were enrolled between 2011 and 2015. Mean body mass index was 26.5 kg/m2. Four cases were steroid-induced, and the remaining 12 cases were idiopathic. All patients presented with neurological deficits in the lower extremities. Cauda equina syndrome (CES) alone was seen in 8 patients, radiculopathy alone in 4, and both radiculopathy and CES (mixed CES) in 4. All patients subsequently underwent laminectomy with epidural lipomatosis resection and were followed-up for more than 1 year. We investigated the clinical course and imaging and measured epidural pressures during surgery. RESULTS: Subjective symptoms improved within 1 week after surgery. Mean Japanese Orthopaedic Association (JOA) score was 15.2 ± 2.8 before surgery, improving to 25.4 ± 2.5 at 1 year after surgery. On magnetic resonance imaging, all lipomatosis lesions included the L4-5 level. On preoperative computed tomography, saucerization of the laminae was not observed in radiculopathy cases, whereas saucerization of the posterior vertebral body was observed in all radiculopathy or mixed CES cases. Intraoperative epidural pressures were significantly higher than preoperative subarachnoid pressures. The results suggest that high epidural pressure resulting from the proliferation of adipose tissue leads to saucerization of the lumbar spine and subsequent symptoms. CONCLUSIONS: Clinical courses were satisfactory after laminectomy. In LEL, epidural pressure increases and symptoms develop through the abnormal proliferation of adipose tissue. Higher epidural pressures induce saucerization of the laminae and/or posterior vertebral body. Furthermore, the direction of proliferative adipose tissue (i.e., site of saucerization) might be related to the types of neurological symptoms.