The factors related to the poor ADL in the patients with osteoporotic vertebral fracture after instrumentation surgery.

PURPOSE: Osteoporotic vertebral fracture (OVF) with nonunion or neurological deficit may be a candidate for surgical treatment. However, some patients do not show improvement as expected. Therefore, we conducted a nationwide multicenter study to determine the predictors for postoperative poor activity of daily living (ADL) in patients with OVF. METHODS: We retrospectively reviewed the case histories of 309 patients with OVF who underwent surgery. To determine the factors predicting postoperative poor ADL, uni- and multivariate statistical analyses were performed. RESULTS: The frequency of poor ADL at final follow-up period was 9.1%. In univariate analysis, preoperative neurological deficit (OR, 4.1; 95% CI, 1.8-10.3; P < 0.001), perioperative complication (OR, 3.4; P = 0.006), absence of preoperative bone-modifying agent (BMA) administration (OR, 2.7; P = 0.03), and absence of postoperative recombinant human parathyroid hormone (rPTH) administration (OR, 3.9; P = 0.006) were significantly associated. In multivariate analysis, preoperative neurological deficit (OR, 4.6; P < 0.001), perioperative complication (OR, 3.4; P = 0.01), and absence of postoperative rPTH administration (OR, 3.9; P = 0.02) showed statistical significance. CONCLUSIONS: Preoperative neurological deficit, perioperative complication, and absence of postoperative rPTH administration were considered as predictors for postoperative poor ADL in patients with OVF. Neurological deficits and complications are often inevitable factors; therefore, rPTH is an important option for postoperative treatment for OVF. These slides can be retrieved under Electronic Supplementary Material.

Scoring system for prediction of metastatic spine tumor prognosis.

Assessing the prognosis before treatment for metastatic spine tumor is extremely important in therapy selection. Therefore, we review some prognostic scoring systems and their outcomes. Articles with combinations of two keywords among "metastatic spine tumor" and "prognosis", "score", "scoring system", "predicting", or "life expectancy" were searched for in PubMed. As a result, 236 articles were extracted. Those referring to representative scoring systems about predicting the survival of patients with metastatic spine tumors were used. The significance and limits of these scoring systems, and the future perspectives were described. Tokuhashi score, Tomita score, Baur score, Linden score, Rades score, and Katagiri score were introduced. They are all scoring systems prepared by combining factors that affect prognosis. The primary site of cancer and visceral metastasis were common factors in all of these scoring systems. Other factors selected to influence the prognosis varied. They were useful to roughly predict the survival period, such as, "more than one year or not" or "more than six months or not". In particular, they were utilized for decision-making about operative indications and avoidance of excessive medical treatment. Because the function depended on the survival period in the patients with metastatic spine tumor, it was also utilized in assessing functional prognosis. However, no scoring system had more than 90% consistency between the predicted and actual survival periods. Future perspectives should adopt more oncological viewpoints with adjustment of the process of treatment for metastatic spine tumor.

A novel pedicle screw with mobile connection: a pilot study.

To prevent adjacent disc problems after spinal fusion, a pedicle screw with a mobile junction between the head and threaded shaft was newly developed. The threaded shaft of the screw has 10 degrees mobility in all directions, but its structure is to prevent abnormal translation and tilting. This screw was evaluated as follows: (1) endurance test: 10(6) times rotational stress was applied; (2) biological reactions: novel screws with a mobile head and conventional screws with a fixed head were inserted into the bilateral pedicles of the L3, L4, and L5 in two mini pigs with combination. Eight months after surgery, vertebral units with the screw rod constructs were collected. After CT scan, the soft and bony tissues around the screws were examined grossly and histologically. As a result, none of the screws broke during the endurance test stressing. The mean amount of abrasion wear was 0.0338 g. In the resected mini pig section, though zygapophyseal joints between fixed-head screws showed bony union, the amount of callus in the zygapophyseal joints connected with mobile-head screws was small, and joint space was confirmed by CT. No metalloses were noted around any of the screws. Novel screws were suggested to be highly durable and histologically safe.

Impact of passive smoking on the bones of rats.

Many epidemiological surveys have identified smoking as a risk factor for osteoporosis, but it is unclear whether smoking has a direct effect on bone metabolism and if such an effect could cause osteoporosis. Therefore, we examined whether smoking causes osteoporosis based on the impact of smoke exposure on the bones of rats. A rat model of passive cigarette smoking was prepared by breeding rats in a cigarette-smoking box for 4 or 8 weeks. Histological changes, micro-computed tomographic (CT) analysis, mechanical bone strength, and bone mineral density of the femur and lumbar vertebrae were examined in these rats and in control rats that were not exposed to smoke. Lower mechanical bone strength was observed in smoke-exposed rats, but these differences were not significant. Significantly lower bone mineral density was found in the femur (P<.01) and lumbar bones (P<.001) of 8-week smoke-exposed rats compared to controls. In a micro-CT scan of lumbar vertebrae, the bone volume, trabecular thickness, trabecular number, and trabecular separation differed significantly between smoke-exposed rats and controls. Histologically, the osteocytes in the smoke-exposed rats were small (approximately 25% of the size in controls), and decreased numbers of marrow cells and osteoblasts (P<.01), as well as a black carbon dust-like substance, were found in the bone of smoke-exposed rats. These results indicate that smoking significantly decreases bone mineral density, which causes osteoporosis, and the organizational changes in the bone suggest a direct effect of smoking on bone structure. Fewer marrow cells were present in the smoke-exposed rats, and a black carbon dust-like substance was observed.

C1-C2 intra-articular screw fixation for atlantoaxial subluxation due to rheumatoid arthritis.

While various surgical procedures have been developed for the treatment of atlantoaxial subluxation due to rheumatoid arthritis, C1-C2 intra-articular screw fixation was developed to reduce intraoperative injuries to vertebral arteries. The purpose of this study was to report the therapeutic outcome of this procedure, which was followed for >2 years. Preoperative symptoms were alleviated in all patients. Only 1 patient with subaxial canal stenosis underwent additional laminoplasty during follow-up. All patients with class IIIA or milder neural deficit according to Ranawat's classification showed improvement to class I or II. There were no surgery-related complications or incidents, including injuries to vertebral arteries. Bone union was observed in all patients. No change was observed in the reduced atlas-dens interval during follow-up. The atlantoaxial angle was -6 degrees to 30 degrees (average, 19.4 degrees) at follow-up, and was >or=30 degrees after surgery (fusion in an overextended position) in only 1 patient. Although postoperative deterioration of cervical alignment was observed in 4 patients (18.2%), there was no additional surgery due to deterioration of cervical alignment. With no surgery-related complications or incidents, this procedure could be a safe and acceptable option for atlantoaxial subluxation due to rheumatoid arthritis.

Outcome of treatment for spinal metastases using scoring system for preoperative evaluation of prognosis.

STUDY DESIGN: Prospective study. OBJECTIVE: To evaluate our treatment outcome for spinal metastases using our treatment strategy based on prognostic scoring system. SUMMARY OF BACKGROUND DATA: In the treatment of spinal metastases, life expectancy is most important, and our scoring system for metastatic spine tumor prognosis has been useful for such prognostic evaluation. METHODS: Conservative treatment or palliative surgery was indicated in patients with a predicted prognosis of less than 6 months or in those with multiple vertebral metastases, whereas excisional surgery was performed in patients with a predicated prognosis of 1 year or more, or with a predicted prognosis of 6 months or more, and with metastasis in a single vertebra. One hundred eighty-three patients were prospectively treated according to this principle using our prognostic scoring system, and the outcome was evaluated. RESULTS: The consistency rate between the predicted prognosis from the criteria of the scoring system and the actual survival period was high in patients within each score range (0-8, 9-11, or 12-15), 87.9% in the 183 patients. Only the palliative surgery group (n = 55) showed a significant improvement of the Barthel index between before and after treatment (P < 0.01). The mean maximum Barthel index after treatment in any modality ran parallel to the total scores of our scoring system. CONCLUSION: The prognostic criteria using our scoring system were useful for the pretreatment evaluation of prognosis irrespective of the treatment modality. In any treatment, the survival period of the patients affected the functional prognosis; therefore, it may be appropriate and realistic to select treatment methods by giving first priority to the life expectancy of patients.

A patient with two re-surgeries for delayed myelopathy due to progression of ossification of the posterior longitudinal ligaments after cervical laminoplasty.

STUDY DESIGN: Case report. OBJECTIVE: To discuss the development of delayed myelopathy due to the progression of ossification of the posterior longitudinal ligament (OPLL) after cervical laminoplasty. SUMMARY OF BACKGROUND DATA: The progression of OPLL after cervical laminoplasty for the treatment of OPLL is often shown in long-term follow-up; however, few patients with reoperation due to OPLL progression have been reported. METHODS: The patient was a 70-year-old male carpenter. At 57-years of age, he underwent open door laminoplasty between C3 and C7 with dome-like laminectomy of C2 for the treatment of myelopathy due to mixed-type OPLL (continuous type at C3-C4 and segmental type at C5). Five years after the initial surgery, the disorder of skilled motor activity in the bilateral hands and ambulatory difficulties recurred as a result of cranial progression of OPLL (between C2 and C4). He underwent laminectomy and posterior fusion between C2 and C5 and returned to work. Four years after resurgery, the same symptoms recurred. RESULTS: CT revealed the progression of OPLL thickness at C5 level and longitudinal progression of OPLL to C6/7. Sagittal view of MRI demonstrated spinal cord compression between C5 and C6/7 because of OPLL at C5 and hypertrophic ligamentum flavum at C5-C6 and C6-C7. Posterior fusion extending up to C7 with laminectomy of C6 and C7 was performed. His symptoms were alleviated and he could walk again. CONCLUSION: We reported a patient with OPLL who had undergone resurgery twice because of myelopathy due to the progression of ossification. It was important to establish a sufficiently longitudinal and transverse decompression, taking the risk of the unexpected progression of ossification into consideration.

Algorithms and planning in metastatic spine tumors.

Metastatic spine tumors cause the loss of the supporting function of the spine through vertebral destruction or invade and compress the spinal cord or cauda equine. As a result, metastatic spine tumor causes severe pain, paralysis, or impairment of activities of daily living (ADL). Also, because the finding of metastatic foci in the spine suggests a generalized disorder, life expectancy and treatment options have many limitations. For this reason, treatment is primarily symptomatic, and the major goals in selecting therapeutic modalities are to relieve pain, prevent paralysis, and improve ADL. This article discusses the selection of treatment for metastatic spine tumors and, in particular, the indications for surgical treatment.

Follow-up of patients with delayed union after posterior fusion with pedicle screw fixation.

STUDY DESIGN: A retrospective study. OBJECTIVE: To investigate the long-term course of patients with delayed union after posterior fusion with pedicle screw fixation (PS) for degenerative lumbar disease. SUMMARY OF BACKGROUND DATA: There have been few studies on the long-term course of patients with delayed union after posterior fusion with PS. METHODS: The subjects were 48 patients (54 discs) with delayed union 2 years after PS, who showed no or only mild symptoms, and could be observed for 3 years or longer thereafter. All had received an autograft using iliac bones, and the method was posterior lumbar interbody fusion in 12 disc levels and posterolateral lumbar fusion in 42 disc levels. Delayed union occurred in 28 disc levels with neurologically responsible lesions (Group A) and in 26 disc levels at the ends of multilevels fusions (Group B). Serial changes in radiographic and clinical findings were evaluated. RESULTS: In Group A, bone union was observed more than 2 years after surgery in 10 disc levels of 9 patients (34.6%). In Group B, bone union was observed in 4 disc levels of 4 patients (18.2%). In the bone union group of both groups, the mean maximum postoperative intervertebral range of motion was significantly smaller than that in the persistent delayed union group (P < 0.05). The disc height generally decreased with time, but the decrease was significantly larger in the bone union group (P < 0.05). In both groups, clinical results were excellent or good in 100% of patients. No significant difference was noted between the bone union and persistent delayed union groups. CONCLUSION: Bone union occurred more than 2 years after posterior fusion with PS in about 30% of patients with delayed union. Its occurrence was related to the intervertebral range of motion and disc height. Firm bone union was not necessarily essential for good clinical results.