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Biomedical subjects

Mikio Kamimura

Publications and source records attributed to Mikio Kamimura.

At least 19 recordsLinked to original sources

Radiographic evaluation of vertebral fractures in osteoporotic patients.

Vertebral fractures, are a serious clinical problem for elderly osteoporotic patients, have been increasingly recognized and are now common. On the assumption that it is difficult to diagnose osteoporotic vertebral fractures on plain radiographs, we studied 78 consecutive patients aged over 50 years with severe back pain with or without minor trauma. All patients had been admitted to our department and had undergone radiographic examinations including plain radiography, magnetic resonance imaging (MRI) and bone scintigraphy. Surprisingly, 74 of the patients (94.9%) with severe back pain had vertebral fractures. Low intensity on T1-weighted MRI indicated that the severe back pain was a symptom of vertebral fracture. The patients were divided into two groups: those with total, and those with partial T1-weighted hypointensity of the vertebral body on MRI. Thirty-five of the vertebral fractures (47.3%) were not detectable on plain radiographs, and patients without trauma showed vertebral deformity more frequently than those with trauma. The patients were treated conservatively with bed rest until the severe back pain had subsided, after which they were evaluated clinically. The average period of bed rest was 22.3 days, which did not differ significantly in relation to the occurrence of trauma, the extent of the signal change in the vertebral body on MRI or the presence of vertebral deformity. Even without vertebral deformity or trauma, vertebral fractures required long periods of bed rest for pain relief and entailed serious clinical problems.

Aged↗

Optimal duration of conservative treatment for lumbar disc herniation depending on the type of herniation.

Six hundred and six clinical records of patients who were admitted to the Department of Orthopaedic Surgery, Suwa Red Cross Hospital, Nagano, Japan, due to lumbar disc herniation (LDH) between 1991 and 2002 were reviewed to determine the ideal conservative treatment period in relation to different types of LDH: contained and non-contained. Since 1997, we have prolonged in-hospital conservative treatment over a few weeks, which resulted in a decrease in the number of surgeries for non-contained LDH, especially of surgeries performed within 1 month. The number of surgeries for contained LDH did not decrease. The preoperative period of non-contained LDH was significantly shorter than that of contained LDH. These results indicate that for patients who have non-contained LDH, intensive conservative treatment may avoid a surgical procedure. For those patients who have contained LDH, conservative treatment should not be prolonged. We believe that the optimal duration of intensive conservative therapy should be less than 1 month.

Adolescent↗

Computer-assisted screw insertion for cervical disorders in rheumatoid arthritis.

To reconstruct highly destructed unstable rheumatoid arthritis (RA) cervical lesions, the authors have been using C1/2 transarticular and cervical pedicle screw fixations. Pedicle screw fixation and C1/2 transarticular screw fixation are biomechanically superior to other fixation techniques for RA patients. However, due to severe spinal deformity and small anatomical size of the vertebra, including the lateral mass and pedicle, in the most RA cervical lesions, these screw fixation procedures are technically demanding and pose the potential risk of neurovascular injuries. The purpose of this study was to evaluate the accuracy and safety of cervical pedicle screw insertion to the deformed, fragile, and small RA spine lesions using computer-assisted image-guidance systems. A frameless, stereotactic image-guidance system that is CT-based, and optoelectronic was used for correct screw placement. A total of 21 patients (16 females, 5 males) with cervical disorders due to RA were surgically treated using the image-guidance system. Postoperative computerized tomography and plane X-ray was used to determine the accuracy of the screw placement. Neural and vascular complications associated with screw insertion and postoperative neural recovery were evaluated. Postoperative radiological evaluations revealed that only 1 (2.1%; C4) of 48 screws inserted into the cervical pedicle had perforated the vertebral artery canal more than 25% (critical breach). However, no neurovascular complications were observed. According to Ranawat's classification, 9 patients remained the same, and 12 patients showed improvement. Instrumentation failure, loss of reduction, or nonunion was not observed at the final follow-up (average 49.5 months; range 24-96 months). In this study, the authors demonstrated that image-guidance systems could be applied safely to the cervical lesions caused by RA. Image-guidance systems are useful tools in preoperative planning and in transarticular or transpedicular screw placement in the cervical spine of RA patients.

Aged↗

Usefulness of white blood cell differential for early diagnosis of surgical wound infection following spinal instrumentation surgery.

STUDY DESIGN: The white blood cell (WBC) count and WBC differential were measured prospectively in patients after spinal instrumentation surgery with or without surgical wound infection. OBJECTIVES.: To investigate the usefulness of WBC differential for early diagnosis of surgical wound infection after spinal instrumentation surgery. SUMMARY OF BACKGROUND DATA: Renewed elevation of C-reactive protein (CRP) or WBC, gallium scan, and CRP/transthyretin mass concentration ratio were reported for early diagnosis of surgical wound infection. METHODS: A total of 39 patients were enrolled in this study: 13 patients who developed wound infection within 2 weeks after spinal instrumentation surgery (infection group) and 26 patients who were comparable with those patients included in the infection group with regard to age, sex, and surgical techniques used (control group). The WBC count and WBC differential were determined before and after surgery. RESULTS: In both groups, WBC and percentage and number of neutrophils showed nearly same change until postoperative 4 days (day 4). However, in the infection group, these parameters had increased after day 4. In both groups, the percentage and number of lymphocytes decreased to 10% or less and 1,000/microL or less on day 1, respectively. These lymphocyte parameters began to gradually normalize on day 4 and returned to the preoperative level 3 weeks after surgery in the control group. On the other hand, these parameters remained 10% or less and 1,000/muL or less until day 11 in the infection group. In patients with infection, the percentage and number of lymphocytes significantly decreased as early as on day 4. CONCLUSION: Lymphopenia represents immunodepression status, thus indicating the increased susceptibility to infection, which may lead to the development of postoperative infection. If lymphopenia is diagnosed as early as possible, surgical wound infection can be treated promptly without removing the instruments.

Adolescent↗

Pseudoarthrosis of vertebral fracture: radiographic and characteristic clinical features and natural history.

BACKGROUND: We examined mobility based on radiographic appearance, clinical appearance, and the natural course of osteoporotic vertebral pseudoarthrosis (VPA) in a prospective study in 34 consecutive cases of VPA in 27 patients with osteoporosis. METHODS: Conventional lateral, lateral flexion, and extension stress radiography (XP) and supine cross-table lateral XP were performed. Anterior vertebral body height and vertebral kyphotic angle were measured to assess vertebral mobility. If vertebral cleft or vertebral instability, which means a difference in vertebral body height between conventional and supine cross-table lateral XP, was present, VPA was diagnosed. Back pain was classified into five grades. RESULTS: The average anterior vertebral height was 9.9 +/- 5.6 mm on conventional lateral XP; it increased to 11.4 +/- 6.5 mm on extension stress XP (not significant) and 18.3 +/- 5.7 mm on cross-table lateral XP (significant). The vertebral kyphotic angle was 24.1 degrees +/- 9.7 degrees on conventional lateral XP; it decreased to 21.6 degrees +/- 9.8 degrees on extension stress XP (not significant) and 11.8 degrees +/- 8.5 degrees on cross-table lateral XP (significant). Intravertebral clefts were detected by conventional lateral XP, extension stress XP, and supine cross-table XP in 3 of 34 (8.8%), 7 of 21 (33.3%), and 28 of 34 (82.4%) vertebral compression fractures (VCFs), respectively. Surgical treatment was performed in seven patients (two because of severe pain and five because of neurological deficits) and in one patient who died. Except in these eight patients, back pain decreased by at least one grade with time in 18 of 19 patients (95%) in whom the clinical course was analyzed. Radiographic follow-up using supine cross-table XP was performed in 15 of 19 patients. Although 11 of these 15 patients (73%) showed vertebral instability on supine cross-table lateral XP, 10 of 11 patients (91%) did not complain of intolerable back pain during daily activity at the final follow-up. CONCLUSIONS: VPA is often detected on supine cross-table lateral XP but not usually on extension stress XP. Despite the presence of vertebral instability, many patients did not complain of intolerable back pain during their daily activity. Surgical treatment to alleviate back pain should be performed for painful VPA after conservative treatment for about 4 months.

Aged↗

Changes in total alkaline phosphatase level after hip fracture: comparison between femoral neck and trochanter fractures.

BACKGROUND: Biochemical bone metabolic markers are affected by fractures, and total alkaline phosphatase (ALP) is considered one of the bone formation markers. Only a few reports have dealt with changes in bone formation markers during the healing process of bone fragility hip fractures. Despite the difference in the amount of callus formation and bone fusion rate, no significant differences in longitudinal change of total ALP between femoral neck and trochanter fracture have been reported. METHODS: A total of 69 osteoporotic patients with femoral neck or trochanter fracture whose serum concentrations of total ALP were examined at least four times at six periodic examination points (1, 2, 3, 4, 6, and 8 weeks after surgery) and whose state of bone union was obtained within 24 weeks after surgery were selected for this retrospective study. The characteristic longitudinal change of total ALP during the healing process was shown, and the possibility of total ALP as a predictive factor for the state of osteosynthesis of hip fractures is discussed. RESULTS: Changes in the total ALP level according to the healing process were similar for femoral neck and trochanter fractures. The concentration of total ALP rose to a maximum at 3 weeks after surgery and then gradually decreased for both fractures. However, the range of change was significantly greater for trochanter fractures than for femoral neck fractures. For trochanter fractures, total ALP decreased from 3 to 6 weeks after surgery in all but one patient. CONCLUSIONS: Increases in the concentration of total ALP after surgery and the subsequent decreases may reflect the normal healing process. A significant difference in the changes of total ALP after surgery between femoral trochanter and neck fractures was shown. Periodic measurement of total ALP might be useful for obtaining information on the osteosynthesis state.

Age Factors↗

Urinary excretion of type I collagen cross-linked N-telopeptide and serum bone-specific alkaline phosphatase analysis to determine the correlation of age and back-pain related changes in elderly women.

We evaluated bone turnover using biochemical markers in 273 women over 60 years of age with suspected osteoporosis. Their age range was 60-96 years, with an average of 72.7 years. Patients with disorders that might affect bone metabolism were excluded. Those complaining of back pain within 6 months before or after examination were assigned to the back-pain group. Serum bone-specific alkaline phosphatase (BAP) was measured as a bone formation marker, and the urinary N-terminal telopeptide of type I collagen (NTX) was measured as a bone resorption marker. Both BAP and NTX levels increased in individuals over 60 years of age; moreover, these markers were significantly higher in subjects aged over 80 years. Among elderly patients, both BAP and NTX levels were significantly higher in those with back pain than in those without, and in a similar way were observed to increase in parallel with age from the 60-year point. We found that both NTX and BAP increased with aging, and that the increase in these bone turnover markers was closely related to back pain. We also showed that NTX and BAP levels increased significantly in women over 80 years, and specifically in patients with back pain.

Aged↗

Magnetic resonance and computed tomography-based scoring system for the differential diagnosis of vertebral fractures caused by osteoporosis and malignant tumors.

BACKGROUND: Previous reports have described magnetic resonance imaging (MRI) findings alleged to be specific for vertebral fractures caused by malignant lesions. Using such findings for differential diagnosis is often difficult, especially during the early phase of the fracture. With the relative inaccuracy of any single imaging finding, a validated scoring system based on a combination of imaging findings might lead to enhanced diagnostic accuracy. The purpose of this study was to establish a diagnostic scoring system for discriminating osteoporotic vertebral fractures from those caused by malignant tumors on the basis of MRI and computed tomography (CT) findings. METHODS: Ten MRI and CT scan findings of 57 osteoporotic vertebral fractures and 43 neoplastic fractures were retrospectively evaluated for their ability to discriminate between malignant and benign vertebral fractures. RESULTS: The following four MRI and two CT findings were selected as the basis for the scoring system: pedicle or other posterior element involvement; extension into the paravertebral region; preservation of normal bone marrow signal; a continuous black line representing the posterior vertebral body margin on T2-weighted MRI images; osteolytic destruction; and distinct fracture lines on CT. CONCLUSION: By combining the findings common to MRI and CT scans of vertebral fractures, a simple scoring system was devised. This scoring system was found to enhance the accuracy of imaging diagnosis of fractures caused by benign or malignant spinal lesions.

Adult↗

Carpal tunnel syndrome and development of trigger digit.

Although the coexistence of carpal tunnel syndrome and trigger digit in the same hand is well documented, the interactive relationship between them is unclear. This study was conducted to examine the factors that may impact on the development of trigger digit in the hand with idiopathic carpal tunnel syndrome. One hundred and eighty-one patients were enrolled. Their gender, age, dominant side, severity of carpal tunnel syndrome, history or presence of trigger digit, and treatment type were recorded. The patients were evaluated for the presence of trigger digit at 1, 3, 6 and 12 months after surgery or the initial evaluation. Two hundred and sixty-five hands in 152 patients were included in the final assessment. Logistic regression analysis revealed that surgery was a significant risk factor for the onset of trigger digit and may accelerate development of trigger digit when carpal tunnel syndrome was mild to moderate, but not when it was severe. In severe disease, other unknown factors, such as hypertrophy of the flexor tenosynovium, may mask the effect of surgery.

Aged↗

Surgical treatment with instrumentation for severely destructive spondyloarthropathy of cervical spine.

Nine patients with severely destructive spondyloarthropathy and marked neurologic deficits associated with dialysis-related amyloidosis underwent posterior decompression and fusion by means of instrumentation at our institute. All patients showed segmental kyphosis, six patients vertebral ankylosis, and eight patients spondylolisthesis. Spondylolisthesis at two levels was noted in three patients. Of the 11 levels of spondylolisthesis in all, 9 were proximally adjacent and 2 were distally adjacent to vertebral ankylosis. All patients underwent posterior decompression and multisegment fusion with autogenous iliac bone. From three to five spinal segments were fixed. Seven patients underwent posterior fusion by means of a pedicle or lateral mass screw between levels C3 and C7, one patient between C3 and C6, and one between C3 and T1. The clinical rate of improvement at the final follow-up was 74.3%. Though complete stability could not be achieved in three patients, the results were rated as good. No postoperative neurologic deterioration has been observed in this series, nor did any patients die immediately after surgery or during the postoperative follow-up period. As anterior long-span surgery might be too invasive for hemodialysis patients, we think that posterior decompression and fusion may well be a reasonable and effective strategy for severe hemodialysis-associated cervical spondyloarthropathy with neurologic deficits. To achieve complete stability, 360 degrees fusion with both anterior and posterior fixation with instrumentation may be required for these patients.

Aged↗

Neurogenic bladder in patients with cervical compressive myelopathy.

We examined the urinary disturbances in 56 consecutive patients with cervical compressive myelopathy using the latest International Continence Society classification. Of the 56 patients with cervical compressive myelopathy, 29 (52%) had some urinary subjective complaints, whereas the remaining 27 (48%) had none. Urologic examination indicated that 8 of these 29 (28%) patients with urinary complaints had urologic disorders other than neurogenic bladder. Of the remaining 21 patients, only 6 (25%) were judged to have neurogenic bladder on urodynamic study. Urodynamic study may be of limited value in diagnosing urinary disturbance in cervical myelopathy. Further, four cases (83%) showed underactive bladder activity in voiding phase, and only one case (17%) showed overactive bladder activity in filling phase. These results were contrary to those of previous studies indicating that cervical compressive myelopathy is associated with overactive bladder activity in filling phase. There were no significant differences in motor or sensory Japanese Orthopedic Association scores between the patients with and without urinary complaints. However, the patients with urinary complaints had significantly longer durations of myelopathy and delayed motor evoked potential latencies than those without urinary complaints. After surgery, 19 of the 21 (90%) patients with urinary complaints showed recovery from urinary disturbance. Operations in patients with cervical myelopathy were also effective against urinary disturbance. Urinary complaints may be an indication for surgical treatment despite the results of urodynamic study.

Cervical Vertebrae↗

Changes in biochemical markers of bone in patients with insufficiency fractures.

Twelve patients presented at our department with low back or buttock pain and were diagnosed as suffering from insufficiency fracture. All patients were evaluated with plain radiographs, magnetic resonance imaging, and/or bone scintigraphy. We also measured biochemical markers of bone turnover in these patients. Bone scintigraphy revealed a high uptake in the fracture site in all patients with insufficiency fracture. Biochemical markers of bone turnover were significantly increased in all patients, but decreased after the fracture healed and the pain was resolved. In those patients who complained of pain again, the biochemical markers of bone turnover had increased once more, and bone scintigraphy showed a new fracture at a different site. Because the changes in bone turnover markers were closely related to clinical symptoms of insufficiency fracture, we speculated that repeated measurements of bone turnover markers may be informative for discriminating insufficiency fracture from bone metastasis.

Aged↗

Unusual stress fracture of the femoral neck in a young adult not caused by excessive stress: a case report.

A 30-year-old man complained of a 10-day history of gradual onset of severe left leg pain. He did not have any history of trauma or excessive training. Routine laboratory data showed no abnormal findings. He was able to perform passive motions of the hip joint without pain, but active motion of the left hip joint was impossible due to anterolateral thigh pain. Plain radiographs of the hip showed no abnormal findings. However, bone scintigraphy indicated trace accumulation in the left femoral neck, and T(1)-weighted magnetic resonance imaging showed a linear low signal on the inferomedial aspect of the femoral neck. Bone mineral density of the lumbar spine was 1.053 g/cm(2), which ruled out osteoporosis. The thigh pain was resolved 2 months after onset with conservative treatment, when plain radiographs showed sclerotic change and a reduction in the intensity of the low signal of T(1)-weighted magnetic resonance imaging. Our diagnosis of unusual stress fracture indicates that the possibility of stress fractures without bone fragility should be kept in mind when young adults complain of atypical pain even without evidence of unusual activities.

Adult↗

Median nerve damage during two-portal endoscopic carpal tunnel release.

OBJECTIVE: To evaluate the adverse effects of Chow's two-portal endoscopic carpal tunnel release (ECTR) performed by an experienced surgeon on median nerve function in patients with idiopathic carpal tunnel syndrome, as compared to open carpal tunnel release (OCTR). METHODS: Eighty-seven hands subjected to ECTR and 65 hands subjected to OCTR were reviewed. Both groups of patients were similar with regard to age, gender, and severity of the disease. Both groups were compared for the number of hands showing worsening of motor distal latency, sensory conduction velocity, and sensory disturbance after surgery. RESULTS: Thirteen hands of 12 patients showed worsening of median nerve function after ECTR, while only one hand showed worsening after OCTR. This difference was statistically significant (p=0.0041). CONCLUSIONS: Median nerve damage, although transient or not serious, may occur even if the procedure is done correctly.

Adult↗

Progressive symptomatic kyphotic deformity after decompressive surgery for lumbar destructive spondyloarthropathy.

Destructive spondyloarthropathy (DSA) is a serious complication of haemodialysis for end stage renal failure. We present a case of a patient who complained of back pain and cruralgia due to L2-3 disc degeneration with instability, and was treated with posterior decompression and bone grafting. Soon after surgery, the kyphotic deformity progressed and the symptoms deteriorated. A correction of the deformity and posterior fusion was required six years after initial surgery. Pathological findings showed characteristic findings of DSA. Our findings indicate that in some cases with unstable DSA, spinal decompression as well as spinal fixation may be necessary.

Decompression, Surgical↗

[Vertebroplasty].

Vertebroplasty for pseudoartrosis of vertebral fracture using PMMA (polymethylmetacrylate) or CPC (calcium phosphate cement) is a new less invasive surgical method providing sufficient pain relief and correction of kyphosis.

Calcium Phosphates↗