Positional relationship between the Achilles tendon and sural nerve on ultrasound.

PURPOSE: This study sought to clarify the positional relationship between the Achilles tendon and sural nerve using ultrasound. METHODS: We studied 176 legs in 88 healthy volunteers. The positional relationship between the Achilles tendon and sural nerve at heights of 2, 4, 6, 8, 10, and 12 cm proximal from the calcaneus' proximal margin was investigated by distance and depth. Setting the X-axis (left/right) as the horizontal axis and Y-axis (depth) as the vertical axis against ultrasound images, we investigated the distance between the lateral margin of the Achilles tendon to the midpoint of the sural nerve on the X-axis. The Y-axis was split into four zones: the part behind the center of the Achilles tendon (AS), the part in front of the center of the Achilles tendon (AD), the part behind the Achilles tendon (S), and the part in front (D). We investigated the zones through which the sural nerve passed. We also studied any significant differences between the sexes and left/right legs. RESULTS: The mean distance on the X-axis was closest at 6 cm, with 1.1 ± 5.0 mm between them. The sural nerve's position on the Y-axis was such that at positions more proximal than 8 cm, the sural nerve ran through zone S in most legs and moved to zone AS through heights 2-6 cm. No parameters showed significant differences between the sexes or left/right legs. CONCLUSION: We presented the positional relationship between the Achilles tendon and sural nerve and suggested some measures to prevent nerve injury during surgery.

Recompression of Augmented Vertebrae after Balloon Kyphoplasty Is a Risk of Adjacent Vertebral Fracture.

Introduction: This study aimed to identify factors associated with adjacent vertebral fracture (AVF) incidence after balloon kyphoplasty (BKP). Methods: To perform the analyses, 133 vertebrae of 128 patients who underwent BKP for osteoporotic vertebral compression fracture were retrospectively investigated. According to the presence of AVF throughout a 1-year period following BKP, patients were divided into AVF (n = 22) and non-AVF (n = 111) groups. The groups were compared with respect to pre- and postoperative parameters, including the incidence of recompression of augmented vertebrae (RAV). RAV was defined as a decrease in anterior vertebral body height of at least 5 mm within the 3 months that followed BKP. To identify factors associated with AVF incidence, univariate and multivariate analyses were performed. Results: The univariate analysis revealed that the AVF group had a lower cement augmentation ratio, greater preoperative wedge angle, lower preoperative vertebral body height, lower postoperative vertebral body height 3 months post-BKP, and a greater change in vertebral body height and rate of RAV than the non-AVF group. Multivariate analysis revealed that low preoperative vertebral body height and RAV occurrence were associated with AVF incidence. Conclusions: To the best of our knowledge, this study is the first to indicate that RAV is a risk factor for AVF. Study findings indicate that the incidence of AVF can be decreased if RAV development is avoided.

Insufficient Augmentation of Bone Cement Causes Recompression of Augmented Vertebra after Balloon Kyphoplasty.

INTRODUCTION: Balloon kyphoplasty (BKP) is one of the most frequently used clinical methods to relieve pain caused by osteoporotic vertebral compression fracture (OVCF); it can effectively improve the body height of the vertebra. However, recompression of the augmented vertebra (RAV) is often observed after BKP. This study aimed to report factors that are associated with RAV in terms of cement augmentation. METHODS: A total of 78 patients (women, 60; men, 18) were included in this study. RAV was defined as anterior vertebral height loss (VHL), between immediate postoperation and 3 or 6 months after BKP, of more than 5.0 mm. Cement augmentation ratio (CAR) was calculated as the ratio of the maximal height of polymethylmethacrylate (PMMA) to the maximal distance between both end plates. Age, gender, fracture age, CAR, presence of medication for osteoporosis, intervertebral cleft (IVC), and cement leakage were evaluated using Fisher's exact test or Mann-Whitney U test to compare between RAV and non-RAV groups. Aforementioned variables were also analyzed using multiple logistic regression test. A P<0.05 was considered statistically significant. RESULTS: The incidence rates for RAV at 3 and 6 months were 35.9% (28/78) and 38.5% (30/78), respectively. Age (80.1 vs 74.7) was significantly higher in the RAV group, whereas CAR (69.4% vs 77.6%) was lower in the non-RAV group. A multivariate regression analysis revealed that age (odds ratio (OR)=1.12, P=0.001) and CAR (OR=0.91, P=0.001) were independently associated with RAV. CONCLUSIONS: RAV was observed in 38.5% of patients in this study. Older age and low CAR were independently associated with RAV. To prevent RAV, especially in the elderly, augmented PMMA should come in contact with both end plates.

Simultaneous-onset infectious spondylitis with vertebral fracture mimicking an acute osteoporotic vertebral fracture erroneously treated with balloon kyphoplasty: illustrative case.

BACKGROUND: Early balloon kyphoplasty (BKP) intervention for acute osteoporotic vertebral fracture (OVF) has been reported to be more effective than the conservative treatment. However, complications of early BKP intervention are still unknown. OBSERVATIONS: A 71-year-old patient with OVF of L2 underwent BKP 2 weeks after symptom onset. Preoperative magnetic resonance imaging (MRI) and radiograph were compatible with new L2 OVF. Although computed tomography (CT) images revealed the atypical destruction of lower endplate of L2 as OVF, L2 BKP was planned. After BKP, his back pain improved dramatically. Two weeks after BKP, his lower back pain recurred. MRI and CT confirmed the diagnosis of infectious spondylitis with paravertebral abscess formation. With adequate antibiotic treatment and rehabilitation, he was symptom-free and completely ambulatory without signs of infection. LESSONS: Signal changes on the fractured vertebral bodies during initial MRI and fractured vertebral instability on radiograph can mislead the surgeon to interpret the infection as a benign compression fracture. If the patients exhibit unusual destruction of the endplate on CT imaging, "simultaneous-onset" spondylitis with vertebral fracture should be included in the differential diagnosis. To determine the strategy for OVF, preoperative biopsy is recommended if simultaneous-onset spondylitis with vertebral fracture is suspected.

Tin Ring Splint Treatment for Osteoarthritis of the Distal Interphalangeal Joints.

Background: We made a tin ring splint for osteoarthritis of the distal interphalangeal joint that looks attractive and is easy to wear. We report the treatment results with this splint. Methods: We enrolled 30 patients with painful osteoarthritis of the distal interphalangeal joint in this study. A tin ring splint was made with tin alloy containing small quantities of silver. Patients were instructed to wear the splint when they felt pain. Patients were assessed before splint use and after 1, 3, and 6 months of splint use. Endpoints included the numeric pain scale, active arc of motion of the distal interphalangeal joint, Hand 20, functional assessment criteria of the upper extremities, and treatment satisfaction. In addition, data were collected on time to symptom relief and satisfaction related to usability and appearance of the splint (0 = dissatisfied, 10 = satisfied). Results: The numeric pain scale showed significant pain improvement from 58.4 ± 4.1 at baseline to 33.1 ± 4.5 at 1 month, and the Hand 20 score also showed significant improvement from 35.0 ± 4.3 at baseline to 20.2 ± 3.2 after 6 months. Active arc of motion were not changed significantly. Most patients responded that symptoms were relieved by the 10th day after treatment. Satisfaction related to usability was 8.9 ± 0.3, and appearance was 7.6 ± 0.4. Conclusions: A tin ring splint quickly reduced pain, and satisfaction related to usability and appearance was high. This splint could be one choice for conservative treatment of osteoarthritis of the distal interphalangeal joint.

Gait Analysis Using a Support Vector Machine for Lumbar Spinal Stenosis.

Lumbar spinal canal stenosis (LSS) is diagnosed based on physical examination and radiological documentation of lumbar spinal canal narrowing. Differential diagnosis of the level of lumbar radiculopathy is difficult in multilevel spinal stenosis. Therefore, the authors focused on gait analysis as a classification method to improve diagnostic accuracy. The goal of this study was to identify gait characteristics of L4 and L5 radiculopathy in patients with LSS and to classify L4 and L5 radiculopathy using a support vector machine (SVM). The study group comprised 13 healthy volunteers (control group), 11 patients with L4 radiculopathy (L4 group), and 22 patients with L5 radiculopathy (L5 group). Light-emitting diode markers were attached at 5 sites on the affected side, and walking motion was analyzed using video recordings and the authors' development program. Potential gait characteristics of each group were identified to use as SVM parameters. In the knee joint of the L4 group, the waveform was similar to that of normal gait, but knee extension at initial contact was slightly greater than that of the other groups. In the ankle joint of the L5 group, the one-peak waveform pattern with disappearance of the second peak was present in 10 (45.5%) of 22 cases. The total classification accuracy was 80.4% using the SVM. The highest and lowest classification accuracies were obtained in the control group (84.6%) and the L4 group (72.7%), respectively. The authors' walking motion analysis system identified several useful factors for differentiating between healthy individuals and patients with L4 and L5 radiculopathy, with a high accuracy rate.

Differences in Gait Characteristics of Patients with Lumbar Spinal Canal Stenosis (L4 Radiculopathy) and Those with Osteoarthritis of the Hip.

It is important to differentially diagnose thigh pain from lumbar spinal stenosis (particularly lumbar fourth nerve root radiculopathy) and osteoarthritis of the hip. In this study, using a treadmill and a motion analysis method, gait characteristics were compared between these conditions. Patients with lumbar fourth nerve root radiculopathy had increased physiological knee flexion immediately after foot-ground contact, possibly owing to a slight decrease in the muscle strength of the quadriceps femoris muscle. Patients with osteoarthritis of the hip had decreased range of motion of the hip joint probably due to anatomically limited mobility as well as gait strategy to avoid pain resulting from increased internal pressure on the hip joint during its extension. Our facile and noninvasive method can be useful for the differential diagnosis of lumbar spinal canal stenosis from osteoarthritis of the hip.

Identification of the causative disease of intermittent claudication through walking motion analysis: feature analysis and differentiation.

Intermittent claudication is a walking symptom. Patients with intermittent claudication experience lower limb pain after walking for a short time. However, rest relieves the pain and allows the patient to walk again. Unfortunately, this symptom predominantly arises from not 1 but 2 different diseases: LSS (lumber spinal canal stenosis) and PAD (peripheral arterial disease). Patients with LSS can be subdivided by the affected vertebra into 2 main groups: L4 and L5. It is clinically very important to determine whether patients with intermittent claudication suffer from PAD, L4, or L5. This paper presents a novel SVM- (support vector machine-) based methodology for such discrimination/differentiation using minimally required data, simple walking motion data in the sagittal plane. We constructed a simple walking measurement system that is easy to set up and calibrate and suitable for use by nonspecialists in small spaces. We analyzed the obtained gait patterns and derived input parameters for SVM that are also visually detectable and medically meaningful/consistent differentiation features. We present a differentiation methodology utilizing an SVM classifier. Leave-one-out cross-validation of differentiation/classification by this method yielded a total accuracy of 83%.

Main disease classification of intermittent claudication via L1-regularized SVM.

There are multiple diseases that cause intermittent claudication, including lumber spinal canal stenosis (LSS) and peripheral arterial disease (PAD). LSS is categorized on the basis of the diseased part: L4 and L5. The medical treatment for these groups is totally different and the differentiation is important. With this in mind, we examined walking-motion data for patients and derived several features for the differentiation in previous studies. However, these features were not specialized for classification, and there is no guarantee that the features are effective for real differentiation. The present study investigates the possibility of differentiation by gait analysis, via use of an L1-regularized support vector machine (SVM). An L1-regularized SVM can execute both classification and feature selections simultaneously. On the basis of this method, our paper presents the methodology for classifying the underlying disease of the intermittent claudication with an accuracy of 79.7%. In addition, new effective features for the differentiation are extracted.

Lumbar spinal stenosis associated with peripheral arterial disease: a prospective multicenter observational study.

BACKGROUND: Intermittent claudication is a common symptom of both lumbar spinal stenosis (LSS) and peripheral arterial disease (PAD) in middle-aged and elderly people. However, the prevalence and clinical characteristics of LSS with PAD (LSSPAD) have not been investigated in a multicenter study. The aim of this study was to investigate the prevalence and clinical characteristics of LSS associated with PAD. METHODS: 570 patients diagnosed with LSS using a clinical diagnostic support tool and MRI at 64 facilities were enrolled. We evaluated each patient's medical history, physical findings, ankle brachial index, Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) score, and the Short Form 36 (SF-36) score. Statistical analyses were performed to compare LSSPAD patients and LSS patients without PAD using the t test, Mann-Whitney's U test, and multivariate recurrence analysis. p values of <0.05 were considered statistically significant. RESULTS: The LSSPAD group comprised 38 patients (6.7 %); 20 (3.5 %) had pre-diagnosised PAD while 18 (3.2 %) had undetected PAD. The clinical characteristics of these patients were advanced age, diabetes, and a history of ischemic heart disease and cerebrovascular disorder. 570 patients enrolled, and 448 (78.6 %) of those patients were followed up at three months after enrollment. Pain in buttocks and legs improved less in the LSSPAD group than in the LSS group (p < 0.05). Improvements in the "general health" score in SF-36 were lower in the LSSPAD group than in the LSS group (p < 0.05). CONCLUSIONS: Advanced age, diabetes, and a history of cerebrovascular disorder and ischemic heart disease were associated with LSSPAD. Because LSSPAD patients show less improvement in QOL than patients with LSS but without PAD do, clinicians should consider the coexistence of PAD in LSS patients.

Study on differentiation factors for main disease identification of intermittent claudication.

Intermittent Claudication is a walking symptom. After a short time walking, patients suffer from pains at lower limbs. But if taking a rest, the pains can be relieved and they can walk again. Unfortunately, it arises from not one but mainly two kinds of diseases: LSS (lumber spinal canal stenosis) and PAD (peripheral arterial disease). Additionally, it is reported that symptom is similar and LSS groups is furthermore divided into two main groups: L4 and L5 groups. Therefore, it is clinically very important to differentiate which diseases the patients suffer from, PAD, L4 or L5. We aims at developing the system to differentiate them from short walking motion data. In our previous paper, we derived differentiation factors, but did not consider the difference between L4 and L5 and the results are limited. This paper focuses on biarticular muscles associated with the diseases, and derive new and effective differentiation factors. The results supports their effectiveness and validity.

Acute aortic dissection or ruptured aortic aneurysm associated with back pain and paraplegia.

Acute aortic dissection and a ruptured aortic aneurysm are both catastrophic events that usually present suddenly. Although these conditions are relatively uncommon compared to other diseases treated by the orthopedists as a primary practitioner, they are of primary importance. The purpose of this study was to investigate the key points that differentiate these conditions from spinal disease. A review of 50 patients with aortic dissection (n=40) or a ruptured aortic aneurysm (n=10) was performed to determine the manifestations (eg, back pain and paraplegia). We also evaluated the predisposing factor and blood pressure on admission and reviewed clinical imaging (radiographs, computed tomography [CT]) retrospectively. Sudden severe isolated back pain was observed in 18 (45.0%) of 40 patients, and 31 (77.5%) of 40 patients had at least some back pain in aortic dissection, while 1 patient had sudden paraplegia with a ruptured aortic aneurysm. Hypertension was the most predisposing factor and was present in 29 (58.0%) of 50 patients. On admission, hypertension was present in 26 (56.5%) of 46 patients, and hypotension was present in 14 (30.4%) of 46 patients. In all cases, the correct diagnosis was made based on CT. For a patient with an abrupt onset of severe back pain, acute aortic dissection and a ruptured aortic aneurysm should be considered in the differential diagnosis from spinal disease. The most reliable tool for imaging diagnosis was CT.