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Spinal pseudoarthrosis following osteoporotic vertebral fracture: prevalence, risk factors, and influence on patients’ activities of daily living 1year after injury

Spinal pseudoarthrosis following osteoporotic vertebral fracture: prevalence, risk factors, and... Purpose To investigate the prevalence and risk factors and influence of pseudoarthrosis on activities of daily living (ADL) of patients with osteoporotic vertebral fracture (OVF). Methods Spinal pseudoarthrosis is defined as the presence of a cleft in the vertebral body on a lateral X-ray image in the sit- ting position at 1 year after admission. Of the total 684 patients treated for OVF between January 2012 and February 2019 at our institution, 551 patients (mean age, 81.9 years; a male-to-female ratio, 152:399) who could be followed up to 1 year were included in this study. Prevalence, risk factors, and influence of pseudoarthrosis on the ADL of patients as well as fracture type and location were investigated. Pseudoarthrosis was set as the objective variable. Total bone mineral density, skeletal muscle mass index, sex, age, history of osteoporosis treatment, presence of dementia, vertebral kyphosis angle, fracture type (presence of posterior wall injury), degree of independence before admission, history of steroid use, albumin level, renal function, presence of diabetes, and diffuse idiopathic skeletal hyperostosis were set as explanatory variables for multivari- ate analysis of the influence of pseudoarthrosis on the walking ability and ADL independence before and 1 year after OVF. Results In total, 54 (9.8%) patients were diagnosed with pseudarthrosis 1 year after injury (mean age, 81.3 ± 6.5 years; male- to-female ratio, 18:36). BKP was performed in nine patients who did not develop pseudoarthrosis after 1 year. In the multi- variate analysis, only the presence of posterior wall injury was significantly correlated with the presence of pseudoarthrosis (OR = 2.059, p = 0.039). No significant difference was found between the pseudarthrosis group and the non-pseudarthrosis group in terms of walking ability and ADL independence at 1 year. Conclusions The prevalence of pseudoarthrosis following OVF was 9.8%, and its risk factor was posterior wall injury. The BKP group was not included in the pseudoarthrosis group, which may have led to an underestimation of the prevalence of pseudoarthrosis. Summary The prevalence, risk factors, and influence of spinal pseudoarthrosis on patients’ ADL following osteoporotic vertebral fracture (OVF) were investigated. Pseudoarthrosis occurs in 9.8% 1 year after the injury in patients with OVF. Posterior wall injury was the risk factor of pseudoarthrosis. Keywords Osteoporotic vertebral fracture · Pseudoarthrosis · Prevalence · Risk factor · ADL · Gait ability · Multivariate analysis · MRI · BKP · Conservative therapy Introduction OVF cases [5, 6]. However, orthopedic doctors occasionally come across patients in whom early stabilization has not been The prevalence of osteoporotic vertebral fractures (OVFs) achieved [7–13], and the technical terms for this pathology is increasing with the increase in elderly population [1–4]. have not been defined clearly. The Japanese clinical guide- Bone fusion and stabilization are achieved naturally in most line for OVFs was revised in 2012, and pseudoarthrosis of the spine was defined as the lack of visible signs of healing 12 months after the onset of the fracture (Fig. 1). In long-term follow-up of patients with OVFs, pseudoarthrosis developed * Norimitsu Wakao nwakao2009@yahoo.co.jp in many cases 1 year after injury without any adverse compli- cations [10, 14], and the clinical significance and frequency Extended author information available on the last page of the article Vol.:(0123456789) 1 3 45 Page 2 of 8 Archives of Osteoporosis (2023) 18:45 of spinal pseudoarthrosis remain unclear. This study aimed to pain during body movements is relieved (whether or not clarify the clinical significance of vertebral pseudoarthrosis the patient can change positions by himself/herself), (3) by investigating the rate of spinal pseudoarthrosis follow- wearing a brace of sufficient length and starting walking ing OVFs, risk factors for pseudoarthrosis, and influence of training if the pain during body movement is improved, pseudoarthrosis on walking ability and independence in daily (4) starting or continuing osteoporosis treatment, (5) bal- living after 1 year in patients treated at our institution. loon kyphoplasty (BKP) should be considered if pain with movements does not improve after 2–4 weeks, and verte- bral body damage is considered severe on imaging (T1, Materials and methods diffuse low on magnetic resonance imaging (MRI); T2, f luid accumulation, posterior wall injury on MRI) [15]. Eligible subjects were patients with acute OVFs who were The survey items were as follows: (1) presence of pseu- hospitalized and treated in our institution between Janu- doarthrosis (Fig. 1) (spinal pseudoarthrosis is defined as ary 2012 and February 2019. In our institution, patients the presence of a cleft in the vertebral body on a lat- with acute OVFs are treated as inpatients (Fig. 2). After eral X-ray image in the sitting position at 1  year after hospitalization, the treatment strategy for OVFs is as admission); (2) ADL assessment included walking ability follows: (1) bed rest and rehabilitation on the bed until (independent/assisted/unable to walk) before and 1 year patients wear a made-to-order brace, (2) bed rest until the after injury and level of ADL independence (independent/ Fig. 1 Images of patients with AB CD E pseudoarthrosis of L1 fracture. MR T1-weighted image (A), T2-weighted image (B), and STIR image (C) at injury. D shows lateral radiogram at injury. E shows lateral radio- gram 1 year after the injury Fig. 2 Baseline characteristics and flowchart of treatment for OVF 1 3 Archives of Osteoporosis (2023) 18:45 Page 3 of 8 45 non-independent: The level of independence in daily liv- variables as explanatory variables. SAS 9.4 (SAS Institute ing was determined based on the classification of care Inc., Cary, NC, USA) was used, and the significance level level evaluated by long-term care insurance system in was set at p = 0.05. Japan, which all seniors 65  years of age and older are enrolled in.); and (3) patient background factors such as whole-body bone mass measured by dual-energy X-ray Results absorptiometry, skeletal muscle mass index, sex, age, history of osteoporosis treatment before admission, pres- Of the 684 patients treated for OVF between January 2012 and ence of dementia (The presence or absence of dementia February 2019, 551 patients (mean age, 81.8 ± 7.6 years; male- was determined by the mini-mental state examination to-female ratio, 152:399) were followed up 1 year after the injury (MMSE); a score of 27 or higher was considered normal, and eligible in this study. BKP was performed in nine patients and a score of less than 27 was diagnosed as dementia.), who had poor pain relief after conservative treatment and hospi- kyphotic angle of the fractured vertebrae, presence of talization and developed advanced vertebral damage on imaging. posterior wall injury on MRI, degree of independence These patients did not develop pseudoarthrosis after 1 year. The before admission, history of steroid medication, albumin mean duration of bed rest after admission for the 542 patients level, renal function (eGFR), diabetes, and diffuse idi- who did not undergo BKP was 6.3 days. No patients developed opathic skeletal hyperostosis (DISH). The following data osteoporotic-delayed vertebral collapse (ODVC) and paralysis were also obtained: degree of independence, steroid his- requiring surgical treatment by 1 year. Among all patients, 54 tory, albumin level, eGFR, presence of diabetes treatment, (9.8%) were diagnosed with pseudoarthrosis after 1 year (mean and presence of DISH (fusion of consecutive four verte- age, 81.3 ± 6.5 years; male-to-female ratio, 18:36) (Table 1). brae on frontal and lateral X-ray images of the vertebrae). Fracture location with and without pseudoarthrosis is shown in Fig. 3. Fractures occurred more frequently in the thoracolumbar Statistical analysis site and less frequently in the upper thoracic and lower lumbar spine. The number of pseudoarthrosis was also higher in the From these survey items, we first investigated the preva- thoracolumbar site but could not be statistically significant due lence of pseudoarthrosis. Then, the influence of pseudoar - to differences of number of occurrences. The walking ability of throsis on walking ability was investigated by comparing the the patients before and 1 year after injury in the pseudoarthrosis pseudoarthrosis group and the non-pseudoarthrosis group and non-pseudoarthrosis groups is shown in Fig. 4. Although a (Mann–Whitney U test). Factors influencing pseudoarthro- certain number of patients in each group had decreased walk- sis were investigated by univariate and multivariate logistic ing ability and became unable to walk, the presence of a pseu- analyses with pseudoarthrosis as the objective variable and doarthrosis did not signic fi antly ae ff ct the decrease in walking the above survey items as explanatory variables. Items with ability (p = 0.52). Similarly, the results for ADL independence p < 0.10 in the univariate logistic analysis were selected, are shown in Fig. 5. Although a certain number of patients in and multivariate logistic analysis was performed using these each group showed a decrease in ADL independence, as with Table 1 Comparison of pseudoarthrosis and non- pseudoarthrosis groups 1 3 45 Page 4 of 8 Archives of Osteoporosis (2023) 18:45 the walking ability, the presence of a pseudoarthrosis had no sig- Discussion nificant effect on the decrease in ADL independence (p = 0.48). The results of the univariate and multivariate analyses of fac- Based on the results of this study, the pseudoarthrosis rate tors influencing pseudoarthrosis are shown in Table  2. In the was 9.8%. Compared with previous reports in Japan, the univariate analysis, the vertebral kyphosis angle in patients with frequency was slightly low [7, 8, 10, 14, 16]. This result was fracture at admission (OR = 0.968, p = 0.009) and posterior wall possibly influenced by two factors. First, our hospitaliza- injury (OR = 2.561, p = 0.005) were significant (OR = 2.059, tion policy for all patients with OVFs has led to good out- p = 0.039); however, only posterior wall injury was significantly comes of conservative therapy. Inpatient treatment for OVFs correlated with the presence of pseudoarthrosis in the multivari- is available at a few facilities and is especially difficult in ate analysis.　Figure 6 shows the administration of osteoporosis high care units in emergency hospitals. This may naturally medication before injury and 1 year after injury. lead to missed cases, delayed diagnosis, inadequate initial Fig. 3 Fracture location and pseudoarthrosis Fig. 4 Results of walking capa- bility before and 1 year after injury in the pseudoarthrosis group and non-pseudoarthrosis group 1 3 Archives of Osteoporosis (2023) 18:45 Page 5 of 8 45 Fig. 5 Results of autonomy before and 1 year after injury in the pseudoarthrosis group and non-pseudoarthrosis group Table 2 Results of univariate and multivariate analyses Abbreviation: SMI; Skeletal muscle mass index eGFR; estimated glomerular filtration rate,DISH; diffuse idiopathic skeletal hyperostosis Fig. 6 Osteoporosis medication before and 1 year after injury 1 3 45 Page 6 of 8 Archives of Osteoporosis (2023) 18:45 treatment, and inappropriate orthotic prescriptions. Second, MRI signal changes as one of the explanatory variables in BKP was performed in nine cases [15]. These nine patients the future. Patients with OVF and posterior wall injuries are had vertebral stabilization after 1 year and did not belong to predisposed to have difficulty obtaining subsequent vertebral the pseudoarthrosis group. Even considering these differ - fusion, and, if OVF-derived symptoms do not improve after ences in study backgrounds, it is confirmed that pseudoar - careful conservative treatment, minimally invasive surgi- throsis occurs 1 year after OVF in approximately 10–20% cal intervention, including BKP, is necessary before severe of cases. vertebral deformity or neurological manifest develops [15]. Non-union, fusion failure, and pseudoarthrosis following OVFs are considered factors with poor functional prognosis; indeed, some clinical studies have investigated patients with Strength and limitation of this study residual clefts in the vertebral body after a certain period of conservative treatment [7, 10, 12, 13, 16, 17]. However, The study included many OVF cases, and 551 of 684 in long-term follow-up of fracture cases, there are patients (80.6%) were functionally evaluated 1  year after injury. who developed pseudoarthrosis after 1 year without any The number of cases and the small number of dropouts are adverse complications. When spine surgeons reviewed strengths of the study, which increase the reliability of the cases of ODVC requiring major surgical treatment [9], all analysis results but also have limitations. First, the BKP cases involved vertebral instability several months after the group, which is supposed to have a poor functional progno- injury, and vertebral instability does not necessarily result in sis, was not included in the pseudoarthrosis group. This may adverse events such as intractable pain and paralysis. ODVC have led to an underestimation of the prevalence of pseu- occurs within 6 months after the injury, and non-fused verte- doarthrosis in this study. Second, assessment of the effect of brae at 1 year after injury (pseudoarthrosis) may not result in pseudoarthrosis on the patient was limited. Essentially, there significant adverse events. Based on these clinical questions were not many cases in which OVF caused significant func- and characteristics, this study focused on two clinical influ- tional decline 1 year after the injury. Specifically, cases in ences of pseudoarthrosis: walking ability and independence which functional assessment at 1 year was not possible (133 in daily living after 1 year. The results showed that pseu- cases, 19.4% in this study) probably included deaths or cases doarthrosis did not have a significant negative effect on both in which patients had to be transferred or institutionalized to walking ability and independence in daily living. This is new nursing homes due to functional decline. Furthermore, proof knowledge that has not been reported previously. Although of functional decline due to OVF must exclude the influence previous studies have mentioned back pain and health- of other diseases as much as possible. In the present study, related quality of life and have reported inferior outcomes in the patients were evaluated in terms of walking ability and the pseudoarthrosis group compared with the non-pseudoar- independence in daily living, but more detailed evaluation throsis group, influences on walking ability or independence indices (pain, walking speed, walking distance, etc.) would in daily living were not investigated. The results of this study have made a difference. Third, the method of evaluating are of great clinical significance from the viewpoint that the pseudoarthrosis was limited. There is no uniform method for actual functional prognosis after 1 year is more important cleft evaluation 1 year after injury, and the pseudoarthrosis in the case group of patients aged 80 years, since diseases rate would be higher if computed tomography or functional other than OVFs have a diverse effect. radiographic imaging with anterior and posterior bending The results of the multivariate analysis showed that only were used as evaluation methods. This study employed posterior wall injury significantly correlated with the pres- lateral radiography in the sitting position and a method of ence of pseudoarthrosis, which was also consistent with imaging that is thought to have the lowest pseudoarthrosis previous reports [7, 8, 10, 13, 14]. Recently, MR images in diagnosis rate, which may have missed true pseudoarthrosis. the early phase of OVFs predict pseudoarthrosis [14, 15], and diffuse low on T1-weighted images and diffuse low with fluid retention on T2-weighted images may be useful Conclusions prognostic factors for poorer clinical outcome following OVFs. Our study focused on examining more confounding Spinal pseudoarthrosis, which occurs at a certain rate after factors and examined in detail patient factors that have not OVFs, was investigated based on the revised clinical guide- been examined in many previous case studies. The result line for OVFs in 2012. Pseudoarthrosis was observed in 9.8% that only the posterior vertebral wall injury on MRI was of all cases. The influence of pseudoarthrosis was examined significant is very interesting and reinforces the possibility in terms of two aspects: walking ability and independence that the severity of the fracture and the limitation of con- in daily living, but no difference was found between the servative treatment are determined at the time of diagnosis, pseudoarthrosis group and the non-pseudoarthrosis group. as has been reported in the past. The authors plan to add The inclusion of nine patients who underwent BKP in the 1 3 Archives of Osteoporosis (2023) 18:45 Page 7 of 8 45 5. Lee YL, Yip KM (1996) The osteoporotic spine. Clin Orthop non-pseudarthrosis group might have led to bias. The only Relat Res 91–97 significant risk factor that affected pseudoarthrosis was pos - 6. Silverman SL (1992) The clinical consequences of vertebral com- terior wall injury following OVF. pression fracture. Bone 13(Suppl 2):S27-31 7. Hoshino M, Nakamura H, Terai H, Tsujio T, Nabeta M, Nami- Acknowledgements The authors would like to thank Enago (www. kawa T, Matsumura A, Suzuki A, Takayama K, Takaoka K (2009) enago. jp) for the English language review. Factors affecting neurological deficits and intractable back pain in patients with insufficient bone union following osteoporotic Funding This study was supported by JSPS KAKENHI Grant Number vertebral fracture. Eur Spine J 18:1279–1286 18K09086 (2018). 8. Tsujio T, Nakamura H, Terai H, et al. (2011) Characteristic radio- graphic or magnetic resonance images of fresh osteoporotic verte- Data availability Our data investigated in this study is available. bral fractures predicting potential risk for nonunion: a prospective multicenter study. Spine (Phila Pa 1976) 36:1229–1235 Declarations 9. Wakao N, Takeuchi M, Riew DK, Hirasawa A, Imagama S, Kawa- nami K, Matsuo T, Murotani K, Deie M (2018) Effect of an inten- Ethical approval This study was approved by the Ethics and Conflict of sive conservative therapy with daily teriparatide administration Interest Committee of the National Center for Geriatrics and Gerontol- and rehabilitation for osteoporotic delayed vertebral collapse and ogy (No. 1124). It was conducted after disclosing information on the paralysis. Medicine (Baltimore) 97:e10906 conduct of the study. 10. Muratore M, Ferrera A, Masse A, Bistolfi A (2018) Osteoporotic vertebral fractures: predictive factors for conservative treatment failure. A systematic review Eur Spine J 27:2565–2576 Conflicts of interest None. 11. Heini PF (2005) The current treatment--a survey of osteoporotic fracture treatment. Osteoporotic spine fractures: the spine sur- Open Access This article is licensed under a Creative Commons Attri- geon's perspective. Osteoporos Int 16 Suppl 2:85–92 bution 4.0 International License, which permits use, sharing, adapta- 12. McKiernan F, Jensen R, Faciszewski T (2003) The dynamic tion, distribution and reproduction in any medium or format, as long mobility of vertebral compression fractures. J Bone Miner Res as you give appropriate credit to the original author(s) and the source, 18:24–29 provide a link to the Creative Commons licence, and indicate if changes 13. Takahashi S, Hoshino M, Takayama K et al (2017) Time course were made. The images or other third party material in this article are of osteoporotic vertebral fractures by magnetic resonance imag- included in the article's Creative Commons licence, unless indicated ing using a simple classification: a multicenter prospective cohort otherwise in a credit line to the material. If material is not included in study. Osteoporos Int 28:473–482 the article's Creative Commons licence and your intended use is not 14. Inose H, Kato T, Ichimura S, et al. (2020) Risk factors of nonunion permitted by statutory regulation or exceeds the permitted use, you will after acute osteoporotic vertebral fractures: a prospective multi- need to obtain permission directly from the copyright holder. To view a center cohort study. Spine (Phila Pa 1976) 45:895–902 copy of this licence, visit http://cr eativ ecommons. or g/licen ses/ b y/4.0/ . 15. Hoshino M, Takahashi S, Yasuda H, et al. (2019) Balloon kyphop- lasty versus conservative treatment for acute osteoporotic ver- tebral fractures with poor prognostic factors: propensity score matched analysis using data from two prospective multicenter References studies. Spine (Phila Pa 1976) 44:110–117 16. Matsumoto T, Hoshino M, Tsujio T, et al. (2012) Prognostic fac- 1. Bengner U, Johnell O, Redlund-Johnell I (1988) Changes in the tors for reduction of activities of daily living following osteoporo- incidence of fracture of the upper end of the humerus during a tic vertebral fractures. Spine (Phila Pa 1976) 37:1115–1121 30-year period. A study of 2125 fractures. Clin Orthop Relat Res 17. Inose H, Kato T, Shirasawa S, Takahashi S, Hoshino M, Yamato 179–182 Y, Matsukura Y, Hirai T, Yoshii T, Okawa A (2021) Time course 2. Cauley JA, Zmuda JM, Wisniewski SR, Krishnaswami S, Palermo of acute vertebral fractures: a prospective multicenter cohort L, Stone KL, Black DM, Nevitt MC (2004) Bone mineral density study. J Clin Med 10: and prevalent vertebral fractures in men and women. Osteoporos Int 15:32–37 Publisher's note Springer Nature remains neutral with regard to 3. Kanis JA, Johnell O, Oden A, Borgstrom F, Zethraeus N, De Laet jurisdictional claims in published maps and institutional affiliations. C, Jonsson B (2004) The risk and burden of vertebral fractures in Sweden. Osteoporos Int 15:20–26 4. O’Neill TW, Felsenberg D, Varlow J, Cooper C, Kanis JA, Silman AJ (1996) The prevalence of vertebral deformity in European men and women: the European vertebral osteoporosis study. J Bone Miner Res 11:1010–1018 1 3 45 Page 8 of 8 Archives of Osteoporosis (2023) 18:45 Authors and Affiliations 1 1 1 1 2 2 Norimitsu Wakao  · Yoshihito Sakai  · Tsuyoshi Watanabe  · Naoaki Osada  · Takaya Sugiura  · Hiroki Iida  · 2 3 Yuto Ozawa  · Kenta Murotani Yoshihito Sakai Yuto Ozawa jsakai@ncgg.go.jp ozawayuuto2000@yahoo.co.jp Tsuyoshi Watanabe Kenta Murotani tswatana@ncgg.go.jp kmurotani@med.kurume-u.ac.jp Naoaki Osada Department of Orthopedic Surgery National Center n.osada@ncgg.go.jp for Geriatrics and Gerontoloty, Obu, Aichi, Japan Takaya Sugiura Department of Orthopedic Surgery, Nagoya University tsugiura@ncgg.go.jp Graduate School of Medicine, Nagoya, Aichi, Japan Hiroki Iida Biostatistics Center, Kurume University, Kurume, Fukuoka, automaticeye.0213@gmail.com Japan 1 3 http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Archives of Osteoporosis Springer Journals

Spinal pseudoarthrosis following osteoporotic vertebral fracture: prevalence, risk factors, and influence on patients’ activities of daily living 1year after injury

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10.1007/s11657-023-01236-8
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Abstract

Purpose To investigate the prevalence and risk factors and influence of pseudoarthrosis on activities of daily living (ADL) of patients with osteoporotic vertebral fracture (OVF). Methods Spinal pseudoarthrosis is defined as the presence of a cleft in the vertebral body on a lateral X-ray image in the sit- ting position at 1 year after admission. Of the total 684 patients treated for OVF between January 2012 and February 2019 at our institution, 551 patients (mean age, 81.9 years; a male-to-female ratio, 152:399) who could be followed up to 1 year were included in this study. Prevalence, risk factors, and influence of pseudoarthrosis on the ADL of patients as well as fracture type and location were investigated. Pseudoarthrosis was set as the objective variable. Total bone mineral density, skeletal muscle mass index, sex, age, history of osteoporosis treatment, presence of dementia, vertebral kyphosis angle, fracture type (presence of posterior wall injury), degree of independence before admission, history of steroid use, albumin level, renal function, presence of diabetes, and diffuse idiopathic skeletal hyperostosis were set as explanatory variables for multivari- ate analysis of the influence of pseudoarthrosis on the walking ability and ADL independence before and 1 year after OVF. Results In total, 54 (9.8%) patients were diagnosed with pseudarthrosis 1 year after injury (mean age, 81.3 ± 6.5 years; male- to-female ratio, 18:36). BKP was performed in nine patients who did not develop pseudoarthrosis after 1 year. In the multi- variate analysis, only the presence of posterior wall injury was significantly correlated with the presence of pseudoarthrosis (OR = 2.059, p = 0.039). No significant difference was found between the pseudarthrosis group and the non-pseudarthrosis group in terms of walking ability and ADL independence at 1 year. Conclusions The prevalence of pseudoarthrosis following OVF was 9.8%, and its risk factor was posterior wall injury. The BKP group was not included in the pseudoarthrosis group, which may have led to an underestimation of the prevalence of pseudoarthrosis. Summary The prevalence, risk factors, and influence of spinal pseudoarthrosis on patients’ ADL following osteoporotic vertebral fracture (OVF) were investigated. Pseudoarthrosis occurs in 9.8% 1 year after the injury in patients with OVF. Posterior wall injury was the risk factor of pseudoarthrosis. Keywords Osteoporotic vertebral fracture · Pseudoarthrosis · Prevalence · Risk factor · ADL · Gait ability · Multivariate analysis · MRI · BKP · Conservative therapy Introduction OVF cases [5, 6]. However, orthopedic doctors occasionally come across patients in whom early stabilization has not been The prevalence of osteoporotic vertebral fractures (OVFs) achieved [7–13], and the technical terms for this pathology is increasing with the increase in elderly population [1–4]. have not been defined clearly. The Japanese clinical guide- Bone fusion and stabilization are achieved naturally in most line for OVFs was revised in 2012, and pseudoarthrosis of the spine was defined as the lack of visible signs of healing 12 months after the onset of the fracture (Fig. 1). In long-term follow-up of patients with OVFs, pseudoarthrosis developed * Norimitsu Wakao nwakao2009@yahoo.co.jp in many cases 1 year after injury without any adverse compli- cations [10, 14], and the clinical significance and frequency Extended author information available on the last page of the article Vol.:(0123456789) 1 3 45 Page 2 of 8 Archives of Osteoporosis (2023) 18:45 of spinal pseudoarthrosis remain unclear. This study aimed to pain during body movements is relieved (whether or not clarify the clinical significance of vertebral pseudoarthrosis the patient can change positions by himself/herself), (3) by investigating the rate of spinal pseudoarthrosis follow- wearing a brace of sufficient length and starting walking ing OVFs, risk factors for pseudoarthrosis, and influence of training if the pain during body movement is improved, pseudoarthrosis on walking ability and independence in daily (4) starting or continuing osteoporosis treatment, (5) bal- living after 1 year in patients treated at our institution. loon kyphoplasty (BKP) should be considered if pain with movements does not improve after 2–4 weeks, and verte- bral body damage is considered severe on imaging (T1, Materials and methods diffuse low on magnetic resonance imaging (MRI); T2, f luid accumulation, posterior wall injury on MRI) [15]. Eligible subjects were patients with acute OVFs who were The survey items were as follows: (1) presence of pseu- hospitalized and treated in our institution between Janu- doarthrosis (Fig. 1) (spinal pseudoarthrosis is defined as ary 2012 and February 2019. In our institution, patients the presence of a cleft in the vertebral body on a lat- with acute OVFs are treated as inpatients (Fig. 2). After eral X-ray image in the sitting position at 1  year after hospitalization, the treatment strategy for OVFs is as admission); (2) ADL assessment included walking ability follows: (1) bed rest and rehabilitation on the bed until (independent/assisted/unable to walk) before and 1 year patients wear a made-to-order brace, (2) bed rest until the after injury and level of ADL independence (independent/ Fig. 1 Images of patients with AB CD E pseudoarthrosis of L1 fracture. MR T1-weighted image (A), T2-weighted image (B), and STIR image (C) at injury. D shows lateral radiogram at injury. E shows lateral radio- gram 1 year after the injury Fig. 2 Baseline characteristics and flowchart of treatment for OVF 1 3 Archives of Osteoporosis (2023) 18:45 Page 3 of 8 45 non-independent: The level of independence in daily liv- variables as explanatory variables. SAS 9.4 (SAS Institute ing was determined based on the classification of care Inc., Cary, NC, USA) was used, and the significance level level evaluated by long-term care insurance system in was set at p = 0.05. Japan, which all seniors 65  years of age and older are enrolled in.); and (3) patient background factors such as whole-body bone mass measured by dual-energy X-ray Results absorptiometry, skeletal muscle mass index, sex, age, history of osteoporosis treatment before admission, pres- Of the 684 patients treated for OVF between January 2012 and ence of dementia (The presence or absence of dementia February 2019, 551 patients (mean age, 81.8 ± 7.6 years; male- was determined by the mini-mental state examination to-female ratio, 152:399) were followed up 1 year after the injury (MMSE); a score of 27 or higher was considered normal, and eligible in this study. BKP was performed in nine patients and a score of less than 27 was diagnosed as dementia.), who had poor pain relief after conservative treatment and hospi- kyphotic angle of the fractured vertebrae, presence of talization and developed advanced vertebral damage on imaging. posterior wall injury on MRI, degree of independence These patients did not develop pseudoarthrosis after 1 year. The before admission, history of steroid medication, albumin mean duration of bed rest after admission for the 542 patients level, renal function (eGFR), diabetes, and diffuse idi- who did not undergo BKP was 6.3 days. No patients developed opathic skeletal hyperostosis (DISH). The following data osteoporotic-delayed vertebral collapse (ODVC) and paralysis were also obtained: degree of independence, steroid his- requiring surgical treatment by 1 year. Among all patients, 54 tory, albumin level, eGFR, presence of diabetes treatment, (9.8%) were diagnosed with pseudoarthrosis after 1 year (mean and presence of DISH (fusion of consecutive four verte- age, 81.3 ± 6.5 years; male-to-female ratio, 18:36) (Table 1). brae on frontal and lateral X-ray images of the vertebrae). Fracture location with and without pseudoarthrosis is shown in Fig. 3. Fractures occurred more frequently in the thoracolumbar Statistical analysis site and less frequently in the upper thoracic and lower lumbar spine. The number of pseudoarthrosis was also higher in the From these survey items, we first investigated the preva- thoracolumbar site but could not be statistically significant due lence of pseudoarthrosis. Then, the influence of pseudoar - to differences of number of occurrences. The walking ability of throsis on walking ability was investigated by comparing the the patients before and 1 year after injury in the pseudoarthrosis pseudoarthrosis group and the non-pseudoarthrosis group and non-pseudoarthrosis groups is shown in Fig. 4. Although a (Mann–Whitney U test). Factors influencing pseudoarthro- certain number of patients in each group had decreased walk- sis were investigated by univariate and multivariate logistic ing ability and became unable to walk, the presence of a pseu- analyses with pseudoarthrosis as the objective variable and doarthrosis did not signic fi antly ae ff ct the decrease in walking the above survey items as explanatory variables. Items with ability (p = 0.52). Similarly, the results for ADL independence p < 0.10 in the univariate logistic analysis were selected, are shown in Fig. 5. Although a certain number of patients in and multivariate logistic analysis was performed using these each group showed a decrease in ADL independence, as with Table 1 Comparison of pseudoarthrosis and non- pseudoarthrosis groups 1 3 45 Page 4 of 8 Archives of Osteoporosis (2023) 18:45 the walking ability, the presence of a pseudoarthrosis had no sig- Discussion nificant effect on the decrease in ADL independence (p = 0.48). The results of the univariate and multivariate analyses of fac- Based on the results of this study, the pseudoarthrosis rate tors influencing pseudoarthrosis are shown in Table  2. In the was 9.8%. Compared with previous reports in Japan, the univariate analysis, the vertebral kyphosis angle in patients with frequency was slightly low [7, 8, 10, 14, 16]. This result was fracture at admission (OR = 0.968, p = 0.009) and posterior wall possibly influenced by two factors. First, our hospitaliza- injury (OR = 2.561, p = 0.005) were significant (OR = 2.059, tion policy for all patients with OVFs has led to good out- p = 0.039); however, only posterior wall injury was significantly comes of conservative therapy. Inpatient treatment for OVFs correlated with the presence of pseudoarthrosis in the multivari- is available at a few facilities and is especially difficult in ate analysis.　Figure 6 shows the administration of osteoporosis high care units in emergency hospitals. This may naturally medication before injury and 1 year after injury. lead to missed cases, delayed diagnosis, inadequate initial Fig. 3 Fracture location and pseudoarthrosis Fig. 4 Results of walking capa- bility before and 1 year after injury in the pseudoarthrosis group and non-pseudoarthrosis group 1 3 Archives of Osteoporosis (2023) 18:45 Page 5 of 8 45 Fig. 5 Results of autonomy before and 1 year after injury in the pseudoarthrosis group and non-pseudoarthrosis group Table 2 Results of univariate and multivariate analyses Abbreviation: SMI; Skeletal muscle mass index eGFR; estimated glomerular filtration rate,DISH; diffuse idiopathic skeletal hyperostosis Fig. 6 Osteoporosis medication before and 1 year after injury 1 3 45 Page 6 of 8 Archives of Osteoporosis (2023) 18:45 treatment, and inappropriate orthotic prescriptions. Second, MRI signal changes as one of the explanatory variables in BKP was performed in nine cases [15]. These nine patients the future. Patients with OVF and posterior wall injuries are had vertebral stabilization after 1 year and did not belong to predisposed to have difficulty obtaining subsequent vertebral the pseudoarthrosis group. Even considering these differ - fusion, and, if OVF-derived symptoms do not improve after ences in study backgrounds, it is confirmed that pseudoar - careful conservative treatment, minimally invasive surgi- throsis occurs 1 year after OVF in approximately 10–20% cal intervention, including BKP, is necessary before severe of cases. vertebral deformity or neurological manifest develops [15]. Non-union, fusion failure, and pseudoarthrosis following OVFs are considered factors with poor functional prognosis; indeed, some clinical studies have investigated patients with Strength and limitation of this study residual clefts in the vertebral body after a certain period of conservative treatment [7, 10, 12, 13, 16, 17]. However, The study included many OVF cases, and 551 of 684 in long-term follow-up of fracture cases, there are patients (80.6%) were functionally evaluated 1  year after injury. who developed pseudoarthrosis after 1 year without any The number of cases and the small number of dropouts are adverse complications. When spine surgeons reviewed strengths of the study, which increase the reliability of the cases of ODVC requiring major surgical treatment [9], all analysis results but also have limitations. First, the BKP cases involved vertebral instability several months after the group, which is supposed to have a poor functional progno- injury, and vertebral instability does not necessarily result in sis, was not included in the pseudoarthrosis group. This may adverse events such as intractable pain and paralysis. ODVC have led to an underestimation of the prevalence of pseu- occurs within 6 months after the injury, and non-fused verte- doarthrosis in this study. Second, assessment of the effect of brae at 1 year after injury (pseudoarthrosis) may not result in pseudoarthrosis on the patient was limited. Essentially, there significant adverse events. Based on these clinical questions were not many cases in which OVF caused significant func- and characteristics, this study focused on two clinical influ- tional decline 1 year after the injury. Specifically, cases in ences of pseudoarthrosis: walking ability and independence which functional assessment at 1 year was not possible (133 in daily living after 1 year. The results showed that pseu- cases, 19.4% in this study) probably included deaths or cases doarthrosis did not have a significant negative effect on both in which patients had to be transferred or institutionalized to walking ability and independence in daily living. This is new nursing homes due to functional decline. Furthermore, proof knowledge that has not been reported previously. Although of functional decline due to OVF must exclude the influence previous studies have mentioned back pain and health- of other diseases as much as possible. In the present study, related quality of life and have reported inferior outcomes in the patients were evaluated in terms of walking ability and the pseudoarthrosis group compared with the non-pseudoar- independence in daily living, but more detailed evaluation throsis group, influences on walking ability or independence indices (pain, walking speed, walking distance, etc.) would in daily living were not investigated. The results of this study have made a difference. Third, the method of evaluating are of great clinical significance from the viewpoint that the pseudoarthrosis was limited. There is no uniform method for actual functional prognosis after 1 year is more important cleft evaluation 1 year after injury, and the pseudoarthrosis in the case group of patients aged 80 years, since diseases rate would be higher if computed tomography or functional other than OVFs have a diverse effect. radiographic imaging with anterior and posterior bending The results of the multivariate analysis showed that only were used as evaluation methods. This study employed posterior wall injury significantly correlated with the pres- lateral radiography in the sitting position and a method of ence of pseudoarthrosis, which was also consistent with imaging that is thought to have the lowest pseudoarthrosis previous reports [7, 8, 10, 13, 14]. Recently, MR images in diagnosis rate, which may have missed true pseudoarthrosis. the early phase of OVFs predict pseudoarthrosis [14, 15], and diffuse low on T1-weighted images and diffuse low with fluid retention on T2-weighted images may be useful Conclusions prognostic factors for poorer clinical outcome following OVFs. Our study focused on examining more confounding Spinal pseudoarthrosis, which occurs at a certain rate after factors and examined in detail patient factors that have not OVFs, was investigated based on the revised clinical guide- been examined in many previous case studies. The result line for OVFs in 2012. Pseudoarthrosis was observed in 9.8% that only the posterior vertebral wall injury on MRI was of all cases. The influence of pseudoarthrosis was examined significant is very interesting and reinforces the possibility in terms of two aspects: walking ability and independence that the severity of the fracture and the limitation of con- in daily living, but no difference was found between the servative treatment are determined at the time of diagnosis, pseudoarthrosis group and the non-pseudoarthrosis group. as has been reported in the past. The authors plan to add The inclusion of nine patients who underwent BKP in the 1 3 Archives of Osteoporosis (2023) 18:45 Page 7 of 8 45 5. Lee YL, Yip KM (1996) The osteoporotic spine. Clin Orthop non-pseudarthrosis group might have led to bias. The only Relat Res 91–97 significant risk factor that affected pseudoarthrosis was pos - 6. Silverman SL (1992) The clinical consequences of vertebral com- terior wall injury following OVF. pression fracture. Bone 13(Suppl 2):S27-31 7. Hoshino M, Nakamura H, Terai H, Tsujio T, Nabeta M, Nami- Acknowledgements The authors would like to thank Enago (www. kawa T, Matsumura A, Suzuki A, Takayama K, Takaoka K (2009) enago. jp) for the English language review. Factors affecting neurological deficits and intractable back pain in patients with insufficient bone union following osteoporotic Funding This study was supported by JSPS KAKENHI Grant Number vertebral fracture. Eur Spine J 18:1279–1286 18K09086 (2018). 8. Tsujio T, Nakamura H, Terai H, et al. (2011) Characteristic radio- graphic or magnetic resonance images of fresh osteoporotic verte- Data availability Our data investigated in this study is available. bral fractures predicting potential risk for nonunion: a prospective multicenter study. Spine (Phila Pa 1976) 36:1229–1235 Declarations 9. Wakao N, Takeuchi M, Riew DK, Hirasawa A, Imagama S, Kawa- nami K, Matsuo T, Murotani K, Deie M (2018) Effect of an inten- Ethical approval This study was approved by the Ethics and Conflict of sive conservative therapy with daily teriparatide administration Interest Committee of the National Center for Geriatrics and Gerontol- and rehabilitation for osteoporotic delayed vertebral collapse and ogy (No. 1124). It was conducted after disclosing information on the paralysis. Medicine (Baltimore) 97:e10906 conduct of the study. 10. Muratore M, Ferrera A, Masse A, Bistolfi A (2018) Osteoporotic vertebral fractures: predictive factors for conservative treatment failure. A systematic review Eur Spine J 27:2565–2576 Conflicts of interest None. 11. Heini PF (2005) The current treatment--a survey of osteoporotic fracture treatment. Osteoporotic spine fractures: the spine sur- Open Access This article is licensed under a Creative Commons Attri- geon's perspective. Osteoporos Int 16 Suppl 2:85–92 bution 4.0 International License, which permits use, sharing, adapta- 12. McKiernan F, Jensen R, Faciszewski T (2003) The dynamic tion, distribution and reproduction in any medium or format, as long mobility of vertebral compression fractures. J Bone Miner Res as you give appropriate credit to the original author(s) and the source, 18:24–29 provide a link to the Creative Commons licence, and indicate if changes 13. Takahashi S, Hoshino M, Takayama K et al (2017) Time course were made. The images or other third party material in this article are of osteoporotic vertebral fractures by magnetic resonance imag- included in the article's Creative Commons licence, unless indicated ing using a simple classification: a multicenter prospective cohort otherwise in a credit line to the material. If material is not included in study. Osteoporos Int 28:473–482 the article's Creative Commons licence and your intended use is not 14. Inose H, Kato T, Ichimura S, et al. (2020) Risk factors of nonunion permitted by statutory regulation or exceeds the permitted use, you will after acute osteoporotic vertebral fractures: a prospective multi- need to obtain permission directly from the copyright holder. To view a center cohort study. Spine (Phila Pa 1976) 45:895–902 copy of this licence, visit http://cr eativ ecommons. or g/licen ses/ b y/4.0/ . 15. Hoshino M, Takahashi S, Yasuda H, et al. (2019) Balloon kyphop- lasty versus conservative treatment for acute osteoporotic ver- tebral fractures with poor prognostic factors: propensity score matched analysis using data from two prospective multicenter References studies. Spine (Phila Pa 1976) 44:110–117 16. Matsumoto T, Hoshino M, Tsujio T, et al. (2012) Prognostic fac- 1. Bengner U, Johnell O, Redlund-Johnell I (1988) Changes in the tors for reduction of activities of daily living following osteoporo- incidence of fracture of the upper end of the humerus during a tic vertebral fractures. Spine (Phila Pa 1976) 37:1115–1121 30-year period. A study of 2125 fractures. Clin Orthop Relat Res 17. Inose H, Kato T, Shirasawa S, Takahashi S, Hoshino M, Yamato 179–182 Y, Matsukura Y, Hirai T, Yoshii T, Okawa A (2021) Time course 2. Cauley JA, Zmuda JM, Wisniewski SR, Krishnaswami S, Palermo of acute vertebral fractures: a prospective multicenter cohort L, Stone KL, Black DM, Nevitt MC (2004) Bone mineral density study. J Clin Med 10: and prevalent vertebral fractures in men and women. Osteoporos Int 15:32–37 Publisher's note Springer Nature remains neutral with regard to 3. Kanis JA, Johnell O, Oden A, Borgstrom F, Zethraeus N, De Laet jurisdictional claims in published maps and institutional affiliations. C, Jonsson B (2004) The risk and burden of vertebral fractures in Sweden. Osteoporos Int 15:20–26 4. O’Neill TW, Felsenberg D, Varlow J, Cooper C, Kanis JA, Silman AJ (1996) The prevalence of vertebral deformity in European men and women: the European vertebral osteoporosis study. J Bone Miner Res 11:1010–1018 1 3 45 Page 8 of 8 Archives of Osteoporosis (2023) 18:45 Authors and Affiliations 1 1 1 1 2 2 Norimitsu Wakao  · Yoshihito Sakai  · Tsuyoshi Watanabe  · Naoaki Osada  · Takaya Sugiura  · Hiroki Iida  · 2 3 Yuto Ozawa  · Kenta Murotani Yoshihito Sakai Yuto Ozawa jsakai@ncgg.go.jp ozawayuuto2000@yahoo.co.jp Tsuyoshi Watanabe Kenta Murotani tswatana@ncgg.go.jp kmurotani@med.kurume-u.ac.jp Naoaki Osada Department of Orthopedic Surgery National Center n.osada@ncgg.go.jp for Geriatrics and Gerontoloty, Obu, Aichi, Japan Takaya Sugiura Department of Orthopedic Surgery, Nagoya University tsugiura@ncgg.go.jp Graduate School of Medicine, Nagoya, Aichi, Japan Hiroki Iida Biostatistics Center, Kurume University, Kurume, Fukuoka, automaticeye.0213@gmail.com Japan 1 3

Journal

Archives of Osteoporosis – Springer Journals

Published: Mar 29, 2023

Keywords: Osteoporotic vertebral fracture; Pseudoarthrosis; Prevalence; Risk factor; ADL; Gait ability; Multivariate analysis; MRI; BKP; Conservative therapy

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