Masashi Hirano

In Not Only Vertebroplasty but Also Kyphoplasty, the Resolution of Vertebral Deformities Depends on Vertebral Mobility

BACKGROUND AND PURPOSE: It has not been clarified whether the postoperative resolution of vertebral deformities achieved by KP are superior to those achieved by VP. We compared the outcomes of KP and VP, taking into account the presence of vertebral mobility, to determine whether the balloon inflation in KP may contribute to postoperative resolution of the vertebral deformities in patients with VCFs. MATERIALS AND METHODS: The subjects had 34 vertebral bodies treated by VP, and 43 vertebral bodies treated by KP. In all patients, preoperative dynamic imaging was performed to assess the presence of vertebral mobility. First, the vertebral height restoration and kyphotic change were compared between the VP and KP groups. Then, the patients were further divided into 2 groups on the basis of the presence of vertebral mobility, and they were compared within and between the VP and KP groups in relation to the presence of vertebral mobility. RESULTS: Overall, no significant differences were observed in either the vertebral height restoration or kyphotic change between the VP and KP groups (P > .20). Preoperative dynamic imaging identified 19 vertebral bodies each with vertebral mobility in the VP (56%) and KP groups (44%) (P = .21). Within the VP and KP groups, the vertebral height restoration and kyphotic changes were significantly better in patients with vertebral mobility than in those without (P < .01). There were no significant differences between the 2 treatment groups after adjustment for the presence of vertebral mobility (P > .30). CONCLUSIONS: In both the VP and KP groups, the vertebral height restoration and kyphotic change largely depended on the preoperative vertebral mobility. The use of the balloon itself contributed little to resolution of the vertebral deformities.

Comparative Study of Percutaneous Vertebral Body Perforation and Vertebroplasty for the Treatment of Painful Vertebral Compression Fractures

BACKGROUND AND PURPOSE: Percutaneous vertebral body perforation is a new technique for treating painful VCFs. Herein, we compare the therapeutic effect of vertebral perforation and conventional vertebroplasty for treating VCFs. MATERIALS AND METHODS: One hundred eight patients with single painful VCFs were assigned to undergo vertebral perforation (perforation group) or vertebroplasty (PVP group). Clinical outcomes were assessed by using the VAS. The associations of analgesic effect and clinical factors were also analyzed by multivariate regression. Plain radiographs were used to quantify the progression of vertebral body compression after surgery and to evaluate cement leakage and new vertebral fractures. The median follow-up time was 10 months. RESULTS: Baseline characteristics were similar in the 2 groups. No factors correlated with analgesic effects in the PVP group. The analgesic effect of vertebral perforation was, however, related to the preoperative severity of vertebral compression and was low in patients with severe deformity (P < .05). Among patients with preoperative vertebral percentage of compression below 30%, there were no significant differences between the 2 groups in analgesic effect at any postoperative intervals. Progression of vertebral compression after surgery occurred in 22.2% and 16.0% of treated vertebrae in the perforation and PVP groups, respectively (P = .38). Respectively, 3.7% and 20.0% of the perforation and PVP groups had new postoperative fractures during follow-up (P < .05). There were no other complications. CONCLUSIONS: Vertebral perforation was safe and effective for painful VCFs with slight compression. However, vertebroplasty should be considered for patients with marked vertebral body compression.

Validity of Intervertebral Bone Cement Infusion for Painful Vertebral Compression Fractures Based on the Presence of Vertebral Mobility

BACKGROUND AND PURPOSE: It is uncertain whether analgesic effects of vertebroplasty in patients with painful VCF are actually attributable to intervertebral cement infusion. This study aims to assess the validity of cement infusion performed for pain relief based on the presence or absence of pseudoarthrosis. MATERIALS AND METHODS: We compared therapeutic effects between PVP and vertebral perforation without bone cement infusion in patients with painful VCF. The subjects were 64 patients undergoing PVP (PVP group) and 67 undergoing vertebral perforation (perforation group). In all patients, preoperative dynamic radiography was performed to assess the presence of vertebral mobility. Patients were classified into 2 groups, those with and those without vertebral mobility, and changes in VAS and ADL scores before and after surgery were compared between the PVP and perforation groups. RESULTS: Regarding patients with vertebral mobility, VAS improved during the 3 months immediately after surgery in the PVP group compared with the perforation group (P < .05). Although no significant difference in postoperative ADL scores was observed between the 2 treatment groups, the scores 3 months after surgery were better in the PVP group than in the perforation group. Meanwhile, in the subgroup of patients without vertebral mobility, both treatments produced marked pain relief, but the difference was not significant (P > .05). Moreover, there was no difference in ADL scores between the 2 treatment groups. CONCLUSIONS: Intervertebral cement infusion exerts analgesic effects in patients with VCF with pseudoarthrosis. However, in those without vertebral mobility, the analgesic effects of vertebroplasty are the same regardless of bone cement infusion.

Clinical Significance of Postoperative Changes in Redundant Nerve Roots After Decompressive Laminectomy for Lumbar Spinal Canal Stenosis

OBJECTIVE The postoperative time course of redundant nerve roots (RNRs) in patients with lumbar spinal canal stenosis (LSCS) is currently unknown. The purpose of this study is to investigate the relationship between postoperative morphologic changes in detected RNRs and the clinical outcome of patients with LSCS. METHODS A total of 33 symptomatic patients with LSCS who demonstrated RNRs on magnetic resonance imaging (MRI) were treated with decompressive laminectomy alone. On the basis of the MRI scans obtained 7 days after surgery, patients were stratified into two groups: group 1 included patients with resolution of RNRs and group 2 included patients with persistent RNRs. Comparative parameters were examined between the two groups of patients. RESULTS We found that 24 of the 33 patients showed resolution of RNRs and 9 showed persistent RNRs. Although there was no difference in the Japanese Orthopedic Association score between the two groups before treatment, group 1 showed a greater recovery of Japanese Orthopedic Association score 1 month postoperatively. MRI demonstrated that the cross-sectional area of the preoperative dural sac at the stenotic lesion was smaller in group 2 than in group 1; however, there was no difference in cross-sectional area of the postoperative dural sac between the two groups. Within 12 months, there was no evidence of RNRs in six of the nine cases in group 2. CONCLUSION Although most patients with LSCS show postoperative resolution of RNRs detected on MRI, some show persistent RNRs postoperatively. The functional outcome of these patients remains poor even if sufficient expansion of the dural sac is achieved postoperatively.

Safety and therapeutic efficacy of the second treatment for new fractures developed after initial vertebroplasty performed for painful vertebral compression fractures.

Abstract Objectives: There is no report on the safety and therapeutic efficacy of the second treatment for new vertebral fractures developed after vertebroplasty. This study aims to examine the therapeutic effects and clinical characteristics in patients undergoing a second vertebroplasty for these new fractures. Methods: The initial treatment group included 182 patients (276 vertebrae) who underwent vertebroplasty. Among 182 patients, the second treatment group included 34 patients (36 vertebrae) who developed new fractures postoperatively, which were retreated. Analgesic effects on the day following surgery, frequency of new fractures during the 12 month period after surgery, and other clinical characteristics were compared between the initial and second treatment groups. Furthermore, similar comparisons were performed between patients with adjacent and non-adjacent vertebral fractures in the second treatment group. Results: The improvement rates in visual analogue scale (VAS) scores before and after surgery were 83·4% in the initial treatment group and 85·6% in the second treatment group (P  =  0·27). The frequencies of new fractures occurring within 12 months after surgery were 20·9% and 20·6%, respectively. Within the second treatment group, the VAS improvement rates were 76·7% in the adjacent and 88·2% in the non-adjacent vertebral fracture groups (P  =  0·83). However, the frequencies of subsequent new fractures after the second treatment were 31·6% and 5·9%, respectively, being significantly higher in the adjacent vertebral fracture group (P < 0·05). Conclusions: Additional vertebroplasty for new fractures exerts analgesic effects similar to those of the initial procedure. However, we must note that the second treatment for new adjacent vertebral fractures frequently causes more subsequent new fractures in comparison with non-adjacent fractures.