Genetic insights into ossification of the posterior longitudinal ligament of the spine.

Ossification of the posterior longitudinal ligament of the spine (OPLL) is an intractable disease leading to severe neurological deficits. Its etiology and pathogenesis are primarily unknown. The relationship between OPLL and comorbidities, especially type 2 diabetes (T2D) and high body mass index (BMI), has been the focus of attention; however, no trait has been proven to have a causal relationship. We conducted a meta-analysis of genome-wide association studies (GWASs) using 22,016 Japanese individuals and identified 14 significant loci, 8 of which were previously unreported. We then conducted a gene-based association analysis and a transcriptome-wide Mendelian randomization approach and identified three candidate genes for each. Partitioning heritability enrichment analyses observed significant enrichment of the polygenic signals in the active enhancers of the connective/bone cell group, especially H3K27ac in chondrogenic differentiation cells, as well as the immune/hematopoietic cell group. Single-cell RNA sequencing of Achilles tendon cells from a mouse Achilles tendon ossification model confirmed the expression of genes in GWAS and post-GWAS analyses in mesenchymal and immune cells. Genetic correlations with 96 complex traits showed positive correlations with T2D and BMI and a negative correlation with cerebral aneurysm. Mendelian randomization analysis demonstrated a significant causal effect of increased BMI and high bone mineral density on OPLL. We evaluated the clinical images in detail and classified OPLL into cervical, thoracic, and the other types. GWAS subanalyses identified subtype-specific signals. A polygenic risk score for BMI demonstrated that the effect of BMI was particularly strong in thoracic OPLL. Our study provides genetic insight into the etiology and pathogenesis of OPLL and is expected to serve as a basis for future treatment development.

Return-to-Sport Rate, Type of Sport, Frequency of Participation, and Patient Satisfaction After Elective Spinal Surgery in the Elderly Population.

Background: The number of elderly sports participants is increasing, and the possibility of return to sport (RTS) has become an important part of surgical decision making in this population. Purpose: To investigate RTS after elective spinal surgery in elderly patients. Study Design: Case series; Level of evidence, 4. Methods: We enrolled patients aged ≥65 years with a history of preoperative or preinjury sports participation who underwent elective spinal surgery at a single institution between 2019 and 2021. At minimum 12-month follow-up, a questionnaire was administered to each participant to assess postoperative RTS, timing of return, frequency and type of pre- and postoperative activities, and satisfaction (scored 1-10). Descriptive statistical analyses were performed, and regression models were developed to examine the influence of age and sex, as well as surgical site, on RTS. Results: A total of 53 patients (mean ± SD age, 73.8 ± 5.2 years; 24 women) were included, and 23 (43.4%) returned to sports at a median 6 months (interquartile range, IQR, 2-6 months). The RTS rate by surgical site was 17 of 34 (50%) for the lumbar spine and 6 of 17 (35.3%) for the cervical spine. There were no statistically significant differences in RTS rate by surgical site, age, or sex. Overall, 6 of 17 patients returned to golf, 4 of 6 to dance, 2 of 5 to swimming, and 1 of 5 to tennis. Of patients who returned, 34.8% participated in sports 5 times per week and 26.1% participated 3 times per week. The median satisfaction score after RTS was 8 (IQR, 6-9). Conclusion: RTS after spinal surgery was achieved in 43% patients at 1-year minimum follow-up, with high satisfaction scores. More than half of the returning patients participated in sports activities ≥3 times per week.

Arthroscopic treatment for Morel-Lavallée lesion of the thigh: A case report and literature review.

INTRODUCTION: Morel-Lavallée lesion (MLL) is a posttraumatic closed degloving soft tissue injury, in which the subcutaneous tissues are separated from the underlying fascia. Surgical treatment is recommended if conservative management fails. The conventional surgical treatment for the lesion is surgical drainage and debridement. PRESENTATION OF CASE: A 51-year-old male patient presented with swelling of the right thigh incurred during a traffic accident. The lesion was diagnosed with MLL. The MLL was successfully treated with a minimally invasive arthroscopic treatment after failure of conservative treatment. The arthroscopic treatment was chosen because of the patient's comorbidity that posed a risk of surgical wound complications. In addition, negative pressure wound therapy (NPWT) was performed postoperatively to ensure healing and to prevent recurrence of the lesion. The patient was successfully treated and the healing of the lesion was also confirmed with MRI. DISCUSSION: In a patient with a risk of wound complications due to a comorbidity, this minimally invasive arthroscopic treatment is useful. In addition, NPWT was used to ensure healing and to prevent recurrence. Although the use of NPWT combined with endoscopic treatment has not been reported, additional NPWT reported in this case may be helpful to ensure healing. CONCLUSION: In case of MLL with a risk of surgical complications, the arthroscopic treatment is a reasonable method and achieves the goal of an open surgical debridement without increased morbidity.

Association of trajectory of body mass index with knee pain risk in Japanese middle-aged women in a prospective cohort study: the Japan Nurses' Health Study.

OBJECTIVES: To investigate whether body mass index (BMI) trajectory, lifestyle and reproductive factors are associated with knee pain risk among middle-aged women. DESIGN: Prospective study of the Japan Nurses' Health Study (JNHS). SETTING: The JNHS investigates the health of female nurses in Japan. Biennial follow-up questionnaires are mailed to the participants. PARTICIPANTS: The 7434 women aged over 40 years who responded to the 10-year self-administered follow-up questionnaire. PRIMARY OUTCOME MEASURE: Self-reported knee pain at the 10-year follow-up was the primary outcome. We analysed BMI (normal or overweight) trajectory data from a baseline survey to the 10-year follow-up survey using group-based trajectory modelling. Exposure measurements were BMI trajectory, BMI at age 18 years, lifestyle variables and reproductive history. RESULTS: BMI trajectories from baseline to the 10-year follow-up were divided into four groups: remained normal, remained overweight, gained weight or lost weight. At the 10-year follow-up, 1281 women (17.2%) reported knee pain. Multivariable logistic regression analysis revealed that compared with the remained normal group, multivariable-adjusted ORs (95% CI) of knee pain were 1.93 (1.60 to 2.33) for the remained overweight group, 1.60 (1.23 to 2.08) for the gained weight group and 1.40 (0.88 to 2.21) for the lost weight group. The attributable risk percent (95% CI) of the remained overweight group was 48.1% (37.3% to 57.0%) compared with the reference group of remained normal. Alcohol intake at baseline was significantly associated with knee pain. CONCLUSIONS: The lost weight group had a lower risk than the remained overweight group and the gained weight group and did not carry statistically significant risks for knee pain. Weight reduction and maintaining a normal BMI in middle age was important for preventing knee pain in women.

Dynamic Changes of Cauda Equina Motion Before and After Decompressive Laminectomy for Lumbar Spinal Stenosis With Redundant Nerve Roots: Cauda Equina Activation Sign.

STUDY DESIGN: Cross-sectional observational study (consecutive case series). OBJECTIVES: The aim of this study was to define a criterion for achieving successful decompression of lumbar spinal stenosis (LSS) using intraoperative ultrasonography (IOUS) and to investigate the pathogenesis of redundant nerve roots (RNRs) based on the ultrasonographic findings. METHODS: A total of 100 LSS patients (71 males, 29 females, mean age, 71 ± 8 years) with RNRs were enrolled as subjects in this study. IOUS was performed to evaluate pulsatile motion of the cauda equina (PMCE) just before and after decompressive laminectomy. To determine the decompression status of the cauda equina, the ultrasonographic findings were classified into 3 types on the basis of the presence or absence of PMCE: type 1, predecompression PMCE (-) to postdecompression PMCE (+); type 2, pre- and postdecompression PMCE (+); and type 3, pre- and postdecompression PMCE (-). The pathogenesis of RNRs was also investigated based on the ultrasonographic findings. RESULTS: Around the stenosis, PMCE was almost always absent before decompression and appeared after decompression (type 1 in 94 patients, type 2 in 6, type 3 in 0). IOUS showed that, before decompression, the cauda equina was held at the stenosis and could not pulsate beyond the stenotic site, and after decompression, PMCE recovered in the craniocaudal direction, leading to the resolution of RNRs. CONCLUSIONS: The emergence of PMCE can be a sign of successful decompression for LSS. Ultrasonographic findings support the notion that disturbance of PMCE around the stenosis is a basic component of the pathogenesis of RNRs.

Effects of glucosamine in patients with osteoarthritis of the knee: a systematic review and meta-analysis.

Osteoarthritis (OA) of the knee is one of the main causes of mobility decline in the elderly. Non-surgical treatments such as administration of supplements to strengthen the joint cartilage matrix have become popular not only for pain relief but also for joint preservation. Glucosamine has been used in many countries based on the increasing evidence of its effectiveness for OA. Although there are many previous studies and systematic reviews, the findings vary and different conclusions have been drawn. We aimed to review recent randomized controlled trials on glucosamine for knee OA to reveal up-to-date findings about this supplement. We also performed a meta-analysis of some of the outcomes to overcome the unsolved bias in each study. Eighteen articles written between 2003 and 2016 were analyzed. Many used visual analogue scale (VAS) pain scores and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), which were assessed in our meta-analysis. We found a marginally favorable effect of glucosamine on VAS pain scores. The effect on knee function, as measured by the WOMAC, was small and not significant. A newly established knee OA scale, the Japanese Knee Osteoarthritis Measure (JKOM), is commonly used in Japan. Although the number of subjects was small, the JKOM meta-analysis indicated that glucosamine is superior to a placebo in alleviating knee OA symptoms. Given this, we concluded that glucosamine has the potential to alleviate knee OA pain. Further studies are needed to evaluate the effect of glucosamine on knee function and joint preservation, as well as to evaluate the combined effect with other components, such as chondroitin.

D-dimer predicts pulmonary embolism after low-risk spine surgery.

INTRODUCTION: Pulmonary embolism (PE) is a risk of mortality following spine surgery. Many studies have demonstrated that deep venous thrombosis (DVT) may affect and actually advance to PE, but few studies have shown how venous thromboembolism (VTE), including PE and DVT, affect blood markers after spine surgery. In this study, we examined changes in blood markers with PE or DVT after low-risk spine surgery, namely cervical laminoplasty or lumbar laminectomy. METHODS: Seventy-two spine surgery patients were studied. A 16-row multidetector computed tomography was performed before and 3 d after the surgery. Patients with a history of cerebral vascular accident or arterial thrombotic episode or pre-surgical asymptomatic PE or DVT were excluded. Plasma levels of soluble fibrin monomer complex, D-dimer, plasminogen activator inhibitor type-1 (PAI-1), and white blood cell and platelet counts were measured preoperatively and postoperatively at days 1, 3, and 7. RESULTS: No patient developed symptomatic post-surgical VTE. Six patients with asymptomatic PE and six with asymptomatic DVT were detected post-surgery, including one patient with both. D-dimer postoperatively at days 3 and 7 was significantly higher in the post-op PE group than in the no-PE group. PAI-1 preoperatively was significantly higher in the DVT and VTE groups than in the no-DVT and no-VTE groups. CONCLUSIONS: Elevated D-dimer at postoperative days 3 and 7 is a predictive factor for the early diagnosis of PE after spine surgery. Moreover, elevated PAI-1 preoperatively is a predictive factor for the early diagnosis of DVT and VTE. Consequently, PE may occur through a pathway other than DVT.

The 25-question Geriatric Locomotive Function Scale predicts the risk of recurrent falls in postoperative patients with cervical myelopathy.

BACKGROUND: Fall-induced injuries represent a major public health concern for older individuals. The relationship between risk of falling and the severity of locomotive syndrome (LS) remains largely unknown. METHODS: We conducted a retrospective analysis of patients who had undergone surgery from January 2012 to December 2013 and completed at least 1 year of follow-up at 12 participating institutes. Patients completed a questionnaire survey regarding their fall experience during a routine postoperative follow-up. Questionnaire items included the number of falls during the prior postoperative year and the 25-question Geriatric Locomotive Function Scale (GLFS-25). The severity of cervical myelopathy was assessed using the Japanese Orthopaedic Association (JOA) score. We analyzed the association between the incidence of falling and the severity of LS measured by the GLFS-25. RESULTS: Of 360 patients, 61 (16.9%) experienced 1 fall; 31 (8.6%), 2-3 falls; 4 (1.1%), 4-5 falls; and 6 (1.7%), ≥6 falls during the first postoperative year. Thus, 102 (28%) patients experienced at least 1 fall, and 41 (11%) experienced recurrent falls (2 or more falls) during the time period. The mean GLFS-25 score was 30.2 ± 22.7, and 242 (62%) patients had GLFS-25 scores of 16 or higher, which fulfilled the diagnostic criteria for LS. When subjects were categorized into recurrent fallers and non-recurrent fallers, recurrent fallers had a significantly higher GLFS-25 score and a significantly lower extremity motor function score of the JOA score than non-recurrent fallers. The GLFS-25 and lower extremity motor function score of the JOA score yielded the areas under the receiver operating characteristic curves of 0.674 and 0.607, respectively, to differentiate recurrent fallers from non-recurrent fallers. CONCLUSION: Postoperative patients with cervical myelopathy had a 62% prevalence of LS. The GLFS-25 may be useful to predict the risk of recurrent falls in patients with cervical myelopathy.

Characteristics of disability in activity of daily living in elderly people associated with locomotive disorders.

BACKGROUND: Ageing is associated with a decline of motor function and ability to perform daily activities. Locomotive disorders are one of the major disorders resulting in adverse health condition in elderly people. Concept of Locomotive syndrome (LoS) was proposed to tackle the problems and prolong healthy life expectancy of people with locomotive disorders. To develop intervention strategy for LoS it is mandatory to investigate impairments, functional disabilities which people with locomotive disorder experience and to examine relationships among these parameters. For this purpose we have developed Geriatric Locomotive Function Scale-25 (GLFS-25). Though several physical performance tests were reported for identification or monitoring the severity of LoS, there are few studies reported on characteristics of disability which people with locomotive disorders experience. The aim of this study was to report the characteristics of ADL disabilities in elderly people with locomotive disorders in terms of numbers and degree of activity limitations. METHODS: We organized a cohort study and recruited 314 participants aged 65 years and over from five orthopedic clinics or nursing care facilities. This was a cross-sectional study to use the baseline data of such cohort. ADL disabilities were assessed using GLFS-25 scale arranging the GLFS-25 scores in ordinal levels using "R language" program. Numbers and degrees of activity limitations were determined and compared among the levels. Frequency of limitation in activities regarding social activity, housework, locomotion, mobility and self-care was compared among across the disability level. RESULTS: The GLFS-25 score was mathematically categorized into 7 levels. The number of activity limitations and the degrees of each activity limitation were significantly greater in high GLFS-25 levels than in low levels. Difficulties in mobility appeared in less severe level, difficulties in domestic and social life appeared in moderately severe level, and difficulties in self-care appeared in advanced level. CONCLUSIONS: High GLFS-25 score represented high degree of disability on ADLs. Concordant increase of numbers of activity limitation and severity progression in activity limitation may contribute to progression of disability. Activity limitation may occur in the following order: sports activity, walking, transferring, and self-care.

The effect of balneotherapy on pain relief, stiffness, and physical function in patients with osteoarthritis of the knee: a meta-analysis.

This meta-analysis was performed to determine the effect of balneotherapy on relieving pain and stiffness and improving physical function, compared to controls, among patients with knee osteoarthritis. We searched electronic databases for eligible studies published from 2004 to December 31, 2016, with language restrictions of English or Japanese. We screened publications in Medline, Embase, Cochrane library, and the Japan Medical Abstracts Society Database using two approaches, MeSH terms and free words. Studies that examined the effect of balneotherapy for treating knee osteoarthritis of a ≥2-week duration were included. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores were used as the outcome measure. A total of 102 publications were assessed according to the exclusion criteria of the study; eight clinical trial studies, which comprised a total of 359 cases and 375 controls, were included in this meta-analysis. The meta-analysis analyzed improvement in WOMAC score at the final follow-up visit, which varied from 2 to 12 months post-intervention. Our meta-analysis indicates that balneotherapy was clinically effective in relieving pain and stiffness, and improving function, as assessed by WOMAC score, compared to controls. However, there was high heterogeneity (88 to 93%). It is possible that balneotherapy may reduce pain and stiffness, and improve function, in individuals with knee osteoarthritis, although the quality of current publications contributes to the heterogeneity observed in this meta-analysis.

Fall-related Deterioration of Subjective Symptoms in Patients with Cervical Myelopathy.

STUDY DESIGN: Retrospective multi-center study. OBJECTIVE: This study was conducted to clarify the incidence and neurological outcomes of fall-related deterioration of subjective symptoms in patients undergoing surgical treatment. SUMMARY OF BACKGROUND DATA: The evidence that minor trauma, including falls, increases the risk of worsening cervical myelopathy is insufficient. METHODS: A retrospective analysis of patients who had undergone surgery for cervical myelopathy at 12 participating institutes was conducted. Patients who had undergone surgery for symptomatic cervical myelopathy from January 2012 to December 2013 and completed at least 1-year follow-up were included in this study. Data were collected by chart review and a questionnaire that included numbers of recalled falls during the last preoperative year and first postoperative year, circumstances of falls, and whether the patient had experienced fall-related deterioration of subjective symptoms. RESULTS: A total of 360 eligible patients were recruited into the study. Of these, 177 (49%) reported at least one fall during the last preoperative year, and 105 (29%) experienced fall-related deterioration of subjective symptoms. Forty (11%) reported deterioration of numbness in the arms or legs, and 65 (18%) reported deterioration of motor deficits. Incidences of falls and fall-related deterioration of symptoms decreased significantly after surgery. Patients who experienced fall-related deterioration of motor deficits showed significantly worse surgical outcomes as assessed by Japanese Orthopaedic Association (JOA) score compared with those who did not experience deterioration. The optimal cut-off for preoperative JOA score in predicting an increased risk of fall-related deterioration in motor deficits was 8. CONCLUSION: Patients with cervical myelopathy commonly experienced preoperative fall-related deterioration of subjective symptoms, associated with significantly worse neurological outcomes. Surgical treatment significantly reduced the incidence of both falls and fall-related deterioration of subjective symptoms. LEVEL OF EVIDENCE: 4.

Relationship between physician-judged functioning level and self-reported disabilities in elderly people with locomotive disorders.

PURPOSE: Locomotive disorders due to musculoskeletal involvement are one of the main causes requiring long-term care services in aging Japan. "Locomotive syndrome (LoS)" is a concept referring to the condition under which people require assistance from others or at risk in future. The object of this study is to examine the relationship between self-reported measure and physician-judged degrees on ADL disability in elder people with locomotive disorders. METHODS: In a cross-sectional study, 711 patients who were aged 65 years old or more were recruited from 49 outpatient clinics and hospitals. We investigated ADL disabilities by self-reported questionnaire (Geriatric Locomotive Function Scale-25: GLFS-25) and physician-judged grading (Locomotive Dysfunction Grade: LDG) and examined the relationship between these two. RESULTS: We classified the severity of locomotive disability by clinical phenotype into six grades: LDG Grade 1 (N = 77), Grade 2 (213), Grade 3 (139), Grade 4 (162), Grade 5 (78), and Grade 6 (42). The mean of GLFS-25 was 25.9. The mean of GLFS-25 was 5.68 for Grade 1, 14.33 for Grade 2, 22.34 for Grade 3, 35.40 for Grade 4, 43.25 for Grade 5, and 60.24 for Grade 6. Significant differences of GLFS-25 scores were found between adjacent LDGs. CONCLUSIONS: Physician-judged grade of locomotive dysfunction was significantly related to self-reported assessment scale on ADL disability. Physician-judged dysfunction grade is readily administered scale and useful to assess the severity of locomotive dysfunction. Self-reported scale provides precise information on ADL disabilities due to locomotive organ dysfunction and is useful to develop intervention programs.

Epidemiologic survey of locomotive syndrome in Japan.

BACKGROUND: The authors have developed a screening tool, the 25-Geriatric Locomotive Function Scale (GLFS-25), for the early detection of locomotive syndrome (LS). However, few studies have examined the prevalence of LS in the general population. This study estimated the prevalence of LS in Japan using the GLSF-25 and investigated age specific mean values for this scale. METHODS: A nationwide cross-sectional questionnaire survey was conducted to reveal standard values for the GLFS-25 and to estimate the total number of individuals with LS in Japan. Subjects were individuals selected from residents aged 40-79 years in Japan by a stratified, two-stage random sampling method in 2014. The survey period was from February to March 2014. A total of 9028 subjects were invited to participate. The GLFS-25 was used to estimate the prevalence of LS. We also investigated the degree of recognition of LS. RESULTS: Answers for the questionnaire were obtained from 5162 subjects (57.2%); 22.1% of responders had heard of LS. According to the GLSF-25, 614 subjects were regarded as having LS, representing a prevalence of 11.9%. When standardizing this value with the age distribution of the Japanese population, the total number of individuals with LS between the 40s and 70s in Japan was estimated to be approximately 7.5 million. Age specific standard values on the GLFS-25 were 4.4 in the 40s, 5.5 in the 50s, 7.1 in the 60s, and 12.7 in the 70s. The prevalence of LS increased with age and was particularly high in subjects aged 70-79. CONCLUSIONS: The degree of recognition of LS was 22%. This study demonstrated sex- and age specific standard values of the GLFS-25 and estimated the total number of individuals with LS in Japan based on a representative population.

Impact of Axial Neck Pain on Quality of Life After Laminoplasty.

STUDY DESIGN: A prospective study. OBJECTIVE: The aim of this study was to elucidate the impact of axial pain following cervical laminoplasty on health-related quality of life (HRQOL). SUMMARY OF BACKGROUND DATA: Axial neck pain is a frequently encountered complication after laminoplasty. However, limited information is available regarding the time-dependent changes in axial pain and the impact of this pain on clinical outcomes, including HRQOL. METHODS: One hundred sixty-two consecutive patients with cervical myelopathy underwent double-door laminoplasty using hydroxyapatite spacers from 2008 to 2012. The outcome measures included the Japanese Orthopaedic Association score (JOA score), the EuroQol 5 Dimension Questionnaire (EQ-5D), and the Short Form-36 survey (SF-36). The intensity of axial pain was assessed using an 11-point numerical rating scale (NRS). These assessments were conducted preoperatively and at 6-month, 1-year, and 2-year follow-ups. Patient satisfaction with outcome was graded using a 7-point NRS at the 2-year follow-up. RESULT: One hundred twenty-one patients completed the 2-year follow-up. The mean axial pain intensity decreased slightly over time; however, the decrease was not significant. The JOA score, EQ-5D score, and all SF-36 domains, excluding general health perceptions, improved significantly compared with baseline levels at the 6-month follow-up or later. Baseline axial pain intensity showed a significant negative correlation with baseline HRQOL only in the SF-36 bodily pain domain. In contrast, axial pain intensity showed significant negative correlations with all HRQOL measures at the 6-month follow-up. At the 2-year follow-up, patients with an axial pain intensity ≥3 showed significantly worse outcomes than did patients with a pain intensity <3 in the EQ-5D score, SF-36 score, and patient satisfaction grades, but not in the JOA score. CONCLUSION: Axial neck pain has a significant negative impact on clinical outcomes, including a wide range of HRQOL measures and patient satisfaction with outcome, in patients undergoing conventional double-door laminoplasty. LEVEL OF EVIDENCE: 3.

[Lumbar spondylosis].

Lumbar spondylosis is a chronic, noninflammatory disease caused by degeneration of lumbar disc and/or facet joints. The etiology of lumbar spondylosis is multifactorial. Patients with lumbar spondylosis complain of a broad variety of symptoms including discomfort in the low back lesion, whereas some of them have radiating leg pain or neurologenic intermittent claudication (lumbar spinal stenosis). The majority of patients with spondylosis and stenosis of the lumbosacral spine can be treated nonsurgically. Nonsteroidal anti-inflammatory drugs and COX-2 inhibitors are helpful in controlling symptoms. Prostaglandin, epidural injection, and transforaminal injection are also helpful for leg pain and intermittent claudication. Operative therapy for spinal stenosis or spondylolisthesis is reserved for patients who are totally incapacitated by their condition.

[Locomo 25--a screening tool for risk of locomotive syndrome].

Locomo 25 was developed as a screening tool of locomotive syndrome by Japanese orthopedic surgeon group in 2008. It contains 25 questions in terms of musculoskeletal disorder such as walking disability, difficulty in daily living, or suffering pain on body. Its reliability and validity were already confirmed through multi-center study including 731 Japanese elderly people (over 65 y.o. average 77 y.o.). The cutoff score for identifying locomotive syndrome was set at 16, and list-upped person is considered as under high-risk condition who may soon require care services without some medical interventions. We can use Locomo 25 not only as a screening tool of locomotive syndrome but also as a measuring scale for evaluating effects of interventions in individuals.

Progression of ossification of the posterior longitudinal ligament of the thoracic spine following posterior decompression and stabilization.

OBJECT: Despite its potential clinical impact, information regarding progression of thoracic ossification of the posterior longitudinal ligament (OPLL) is scarce. Posterior decompression with stabilization is currently the primary surgical treatment for symptomatic thoracic OPLL; however, it remains unclear whether thoracic OPLL increases in size following spinal stabilization. It is also unknown whether patients' clinical symptoms worsen as OPLL size increases. In this retrospective case series study, the authors examined the postoperative progression of thoracic OPLL. METHODS: Nine consecutive patients with thoracic OPLL who underwent posterior decompression and fixation with a minimum follow-up of 3 years were included in this study. Thin-slice CT scans of the thoracic spine obtained at the time of surgery and the most recent follow-up were analyzed. The level of the most obvious protrusion of ossification was determined using the sagittal reconstructions, and the ossified area was measured on the axial reconstructed scan at the level of the most obvious protrusion of ossification using the DICOM (digital imaging and communications in medicine) software program. Myelopathy severity was assessed according to the Japanese Orthopaedic Association (JOA) scale score for lower-limb motor function on admission, at postoperative discharge, and at the last follow-up visit. RESULTS: The OPLL area was increased in all patients. The mean area of ossification increased from 83.6 ± 25.3 mm(2) at the time of surgery to 114.8 ± 32.4 mm(2) at the last follow-up visit. No patients exhibited any neurological deterioration due to OPLL progression. CONCLUSIONS: The present study demonstrated that the size of the thoracic OPLL increased after spinal stabilization. Despite diminished local spinal motion, OPLL progression did not decrease or stop. Physicians should pay attention to ossification progression in patients with thoracic OPLL.

Preoperative predictors of patient satisfaction with outcome after cervical laminoplasty.

Study design Prospective cohort study. Objective The purpose of the present study was to identify the predictors of patient satisfaction with outcome after cervical laminoplasty for compressive cervical myelopathy. Methods A cohort of 143 patients with compressive myelopathy who underwent cervical double-door laminoplasty between 2008 and 2011 was studied prospectively. The principal outcome was patient satisfaction with outcome at 1 year after surgery. Patient satisfaction was graded on an ordinal scale from 1 to 7. Subjective health-related quality of life (QOL) and objective disease-specific outcome was measured by Short Form-36 (SF-36) and the Japanese Orthopaedic Association (JOA) score, respectively, before surgery and at 1-year follow-up. We evaluated the association between patient satisfaction at 1-year follow-up and various baseline parameters, including patient demographics, duration of symptoms, comorbidities, imaging findings, JOA score, and SF-36 scores. Results A total of 116 patients completed subjective and objective follow-up for a minimum of 1 year. Of 116 patients, 95 patients (81.9%) were satisfied with the outcome ("satisfied a little" or more). The unsatisfied group ("neutral" or less) showed significantly lower baseline SF-36 scores in bodily pain (BP), general health perceptions (GH), and vitality (VT) domains compared with the satisfied group. At the 1-year follow-up, SF-36 scores showed significant differences between the groups in all eight domains, whereas the JOA score showed no significant difference. Conclusions Lower baseline QOL measured by SF-36 scores, specifically in BP, GH, and VT domains, are associated with lower satisfaction with outcome after cervical laminoplasty.

Prevalence of locomotive syndrome in Japan: a nationwide, cross-sectional Internet survey.

BACKGROUND: The authors recently developed a screening tool, the 25-question Geriatric Locomotive Function Scale (GLFS-25), for the early detection of locomotive syndrome (LS). However, the nationwide prevalence of LS based on the GLFS-25 remains unknown. METHODS: A nationwide, cross-sectional Internet survey was conducted to estimate sex- and age-specific mean values of the GLFS-25 and the total number of individuals with LS in Japan. The distribution of the subjects' sex, age, geographical location, and population size was approximated by that observed in the national population census conducted in 2010. In total, 4,500 subjects who completed the GLFS-25 questionnaire on the Internet were included in the present study. RESULTS: The age-specific mean values for the GLFS25 were 5.8 in the 40s, 6.0 in the 50s, 5.9 in the 60s, and 8.8 in the 70s. The mean value for the GLFS-25 was significantly higher in the 70s than in the other age groups. The mean value for the GLFS-25 was significantly higher in females than in males. The prevalence of LS was 8.4% in the 40s and remained stable until the 60s, but increased rapidly in the 70s. The overall mean prevalence of LS was 10.2%. The total number of individuals between the 40s and 70s with LS in Japan was roughly estimated to be 6.5 million. CONCLUSIONS: This study determined sex- and age-specific estimates for the GLFS-25 using a nationwide, cross-sectional Internet survey. The current results highlight the magnitude of the problem associated with LS and encourage further large-scale population-based epidemiologic studies to determine the accurate prevalence of LS using stratified random sampling.

A genome-wide association study identifies susceptibility loci for ossification of the posterior longitudinal ligament of the spine.

Ossification of the posterior longitudinal ligament of the spine (OPLL) is a common spinal disorder among the elderly that causes myelopathy and radiculopathy. To identify genetic factors for OPLL, we performed a genome-wide association study (GWAS) in ∼8,000 individuals followed by a replication study using an additional ∼7,000 individuals. We identified six susceptibility loci for OPLL: 20p12.3 (rs2423294: P = 1.10 × 10(-13)), 8q23.1 (rs374810: P = 1.88 × 10(-13)), 12p11.22 (rs1979679: P = 4.34 × 10(-12)), 12p12.2 (rs11045000: P = 2.95 × 10(-11)), 8q23.3 (rs13279799: P = 1.28 × 10(-10)) and 6p21.1 (rs927485: P = 9.40 × 10(-9)). Analyses of gene expression in and around the loci suggested that several genes are involved in OPLL etiology through membranous and/or endochondral ossification processes. Our results bring new insight to the etiology of OPLL.