Yukihiro Matsuyama

Study Design: A prospective cohort study.Purpose: To determine the age-specific normative values of the prognostic nutritional index (PNI) among elderly residents in Japan and explore the relationship between malnutrition and spinal alignment.Overview of Literature: Nutritional status affects postoperative recovery, with malnourished patients often experiencing severe postoperative complications. PNI is a known nutritional indicator based on serological value; however, there is a dearth of age-specific normative values for PNI, with even less research on the impact of malnutrition on spinal alignment.Methods: We included 237 participants from a 2-yearly resident health checkup conducted in Toei, Aichi, Japan. Participants underwent blood tests and whole-spine standing radiography, and were stratified based on age (60s, 70s, and 80s) and sex to determine age-specific normative PNI values. Additionally, participants were categorized into a lower PNI (PNI <50) or higher PNI (PNI ≥50) group to compare spinal alignment.Results: The average PNI values for different age groups were: 60s: males (n=13): 50.7, females (n=31): 50.9; 70s: males (n=55): 50.3, females (n=57): 50.1; 80s: males (n=28): 49.1, females (n=53): 48.3. For females, the radiographic spinal alignment parameters were comparable between the lower and higher PNI groups; however, in males, significant differences were noted for pelvic tilt (20° vs. 16°, p=0.020), lumbar lordosis (35° vs. 44°, p<0.001), and pelvic incidence minus lumbar lordosis (10° vs. 4°, p=0.013).Conclusions: Malnutrition in males negatively impacts their lumbar-pelvic alignment. While the normative PNI value decreases with age, the two variables show a very weak correlation.

Purpose While 3-column osteotomy (3-CO) is associated with high reoperation and complication rates, long-term outcomes remain unreported. Evaluating long-term outcomes after adult spinal deformity (ASD) surgery with 3-CO is crucial to improving clinical management. In this study, we investigated 10-year postoperative outcomes of corrective fusion surgery with 3-CO in adult patients with spinal deformities, focusing on alignment changes, patient-reported outcomes, and reoperation incidence. Methods Data were retrospectively retrieved from a single-center database of ASD surgeries. This retrospective case series included 84 patients (73 women) who underwent posterior 3-CO fusion for ASD between 2010 and 2014. Spinopelvic parameters were measured using standing whole-spine radiographs obtained from the preoperative period through 10 years postoperatively. Patient-reported outcomes were assessed at the same intervals. Surgical details, complications, and reoperations were recorded. Results The mean age at surgery was 67.1 years. Among 49 patients with follow-up beyond 10 years, all radiographic parameters significantly improved postoperatively, although the pelvic tilt, thoracic kyphosis, and sagittal vertical axis progressively increased over time. The Oswestry Disability Index (%) improved significantly from 45.7 preoperatively to 31.2 at 2 years, 29.0 at 5 years, and 28.4 at 10 years, showing sustained benefit. The most frequent perioperative complication was postoperative delirium, observed in 10 patients. Reoperation was required in 41 patients (52.4%) for a total of 54 procedures. Conclusion Ten-year outcomes of adult patients with spinal deformities treated with 3-CO fusion were relatively favorable. Global alignment improved postoperatively but gradually declined, while patient-reported outcomes improved and were maintained for 10 years.

Background/Objectives: Knee osteoarthritis (KOA) is multifactorial, and longitudinal evidence isolating early predictors remains limited. We investigated predictors of incident KOA in community-dwelling older adult Japanese women. Methods: We analyzed 191 knees from 105 women aged ≥50 years (baseline Kellgren–Lawrence (KL) grade 0–1) and followed them for 8 years. Incident KOA was defined as KL ≥ 2 at the 8-year follow-up. Baseline measures included body mass index (BMI), physical function (one-leg stance, functional reach), Geriatric Locomotive Function Scale (GLFS-25), EuroQol 5-Dimension (EQ-5D) questionnaire, standing lateral whole-spine radiographs (sagittal spinopelvic parameters), and standing full-length anteroposterior (AP) lower-limb radiographs (coronal alignment parameters). Incident KOA was defined as KL ≥ 2 at follow-up. Group comparisons, multivariable logistic regression, and receiver operating characteristic analyses were conducted. Results: Incident KOA occurred in 58/191 knees (mean participant age 69.3 ± 6.1 years). Compared with non-incident knees, incident knees had higher BMI (23.8 vs. 21.1 kg/m²), higher GLFS-25, greater pelvic tilt and pelvic incidence minus lumbar lordosis (PI–LL) mismatch (11.5° vs. 5.3°), and lower EQ-5D, medial proximal tibial angle, and joint line obliquity. BMI was the strongest single predictor (area under the curve [AUC] 0.753). PI–LL mismatch showed limited standalone discrimination (AUC 0.596) but improved discrimination when combined with BMI (AUC 0.803). Conclusions: BMI was the primary predictor of incident KOA in this cohort. PI–LL mismatch, while not strongly discriminative alone, acted as a complementary marker consistent with sagittal-alignment-related mechanical stress. Results suggest that early screening and prevention should prioritize weight management, using spinopelvic parameters to refine risk stratification.

A retrospective multicenter study. This study aimed to examine the impact of screw loosening (SL) on health-related quality of life (HRQOL) following posterior lumbar interbody fusion (PLIF). The rising prevalence of degenerative spinal conditions has led to an increase in lumbar surgeries, including PLIF. SL after PLIF remains challenging; however, its impact on HRQOL remains unclear. This study included 138 patients who underwent PLIF, with a mean age of 67 years and a follow-up period of 12 months. At 12 months postoperatively, lumbar computed tomography (CT) was performed to assess SL, and patients were categorized into SL and nonloosening (NL) groups accordingly. A propensity score-matched model was used to adjust for age, sex, and body mass index (BMI). Propensity score matching was performed to compare outcomes between the SL and NL groups. Among the 138 patients, 29 (21%) developed SL following PLIF. Preliminary analysis revealed that the patients in the SL group were older and exhibited decreased femoral neck bone mineral density, preoperative pelvic retroversion, poor whole spine alignment, and lesser improvement in HRQOL compared with the NL group. Using propensity score matching, 22 patients were selected from each group (mean age, 72 years) (C-statistic=0.78). The propensity score-matched analysis demonstrated significant differences in the preoperative pelvic tilt (25.9° vs. 17.8°, p=0.010) between the matched SL and NL groups. Furthermore, the Oswestry Disability Index scores indicated poorer improvements in the matched SL group than in the matched NL group at 9 months postoperatively (p=0.025). After matching, pre- and postoperative pelvic retroversion were significantly associated with SL. Patients with SL experienced significantly poorer improvement in HRQOL at 9 months postoperatively. Therefore, implementing strategies for preventing SL may enhance early postoperative HRQOL.

Purpose This study aimed to investigate the incidence of and risk factors for proximal junctional kyphosis (PJK) in patients with adolescent idiopathic scoliosis (AIS) and evaluate its relationship with cervical alignment. Methods We retrospectively analyzed the patients with AIS who underwent surgery. The patients were divided into two groups based on the occurrence of PJK. Demographic data, radiographic parameters, and 22-item Scoliosis Research Society Questionnaire (revised) (SRS-22r) scores were compared. Logistic regression analysis was performed to identify the risk factors for PJK. Results Eleven (5.6%) out of 195 patients had PJK. PJK was significantly more common in patients with upper instrumented vertebra (UIV) at T6 (33%) than in those with a UIV at T2–5 (4.8%). PJK was observed in 7 out of 107 patients (6.5%) with pedicle screw constructs and in 4 of 88 patients (4.5%) with hybrid constructs, showing no significant difference. The PJK (+) group had significantly greater preoperative cervical lordosis (CL) (1.5° vs. − 9.5°), greater C2–7 sagittal vertical axis (C2–7 SVA) (30.6 vs. 24.3 mm), greater T1 slope (20.5° vs. 12.5°), and greater T1–12 thoracic kyphosis (32.5° vs. 21.3°) than the PJK (−) group. Multivariate analysis identified preoperative CL and C2–7 SVA as independent risk factors for PJK. There was no difference in the SRS-22r scores between patients with and without PJK. Conclusion Patients with greater preoperative CL, and greater C2–7 SVA have a higher likelihood of developing PJK than their counterparts.

Purpose Spinopelvic sagittal alignment is a critical determinant of the quality of life and clinical outcomes in older adults. Although pelvic incidence (PI) is a well-established morphological parameter influencing spinopelvic alignment, its role in age-related alignment changes and compensatory mechanisms remains incompletely understood. This study aimed to investigate the influence of PI magnitude on 10-year changes in spinopelvic sagittal alignment and compensatory adaptations in a community-dwelling older population. Methods We analyzed 135 adults (mean age: 68.5 years in 2012) who underwent whole-spine lateral radiography between 2012 and 2022. Participants were classified into three groups based on their 2012 PI values: Low PI, Mid PI, and High PI. Radiographic parameters, including thoracic kyphosis (TK), upper and lower lumbar lordosis, sacral slope, pelvic tilt (PT), and sagittal vertical axis (SVA), were compared longitudinally. Changes in alignment were assessed, and compensatory mechanisms were evaluated in relation to PI magnitude. Results Regardless of PI magnitude, participants demonstrated pelvic retroversion and kyphotic changes in the upper lumbar spine over the 10-year period. However, compensatory strategies differed among the groups. Individuals with low PI exhibited increased TK and compensatory hyperlordosis in the lower lumbar region. Conversely, those with high PI showed decreased TK and progressive kyphotic changes in the lower lumbar spine. Notably, no significant group differences were observed in SVA or PT progression. Conclusion PI magnitude significantly influences compensatory mechanisms associated with age-related deterioration of spinopelvic alignment. These findings highlight the need for individualized evaluation and management strategies based on PI morphology in aging populations.