Methods: 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. Results: 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). Conclusions 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.

【Introduction】Thumbtack needles for skin stimulation are used in the field of sports medicine. Their primary therapeutic mechanism is believed to be the increase in regional blood flow mediated by the axon reflex. However, it is not clear at this time whether a medical device (acupuncture device) for skin stimulation significantly increases regional blood flow at the stimulation site. Furthermore, sterile acupuncture needles in which the acupuncture needle body is inserted into the skin with multiple needles (hereafter referred to as Multi-core thumbtack needle) have not been manufactured to date, and their usefulness and potential application for blinding is unknown.【Materials and Methods】A single-blind randomized crossover trial was conducted in 16 healthy adult males. A multi-core thumbtack needle (needle length 0.55 mm, needle base diameter 0.3 mm, number of needles 37, pitch 1.0 mm, made of biosafe resin) was placed in the center of the palmar side of the forearm for 30 seconds, and then one week later they were randomly assigned in a 1:1 ratio to one group to receive stimulation in the same way with a sham needle (a flat disk made of the same material), or one group to receive stimulation in the opposite order. The primary endpoints were the change in regional blood flow (5 min post-stimulation vs. pre-stimulation) and the rate of change at the stimulation site, which were measured using a laser perfusion meter. The secondary endpoint was heart rate. A linear mixed model was used as the statistical method, with a significance level of 5%.【Results】Regarding the amount of change in regional blood flow, sham needles showed a mean of -0.09 (95% confidence interval [CI]: -0.39 to 0.21) mL/min/100g, whereas multi-core thumbtack needles showed a mean of 8.83 (95% CI: 5.86 to 11.79) mL/min/100g, indicating a significant intervention effect (P < 0.001), with no significant period effect (P = 0.474) or carryover effect (P = 0.441). There was no intervention effect on heart rate (P = 0.95).【Conclusion】A significant increase in local blood flow was observed with the use of the multi-core thumbtack needle employed in this study. As this response was not accompanied by a significant increase in heart rate, it is speculated that the effect is primarily mediated by the axonal reflex and the involvement of nitric oxide, as well as somatic-autonomic reflex mechanisms.

The Japan Primary Care Association (JPCA) and Royal College of General Practitioners (RCGP) exchange program aims to provide young family physicians with an international perspective and networking opportunities. The project was planned and presented at the 2024 JPCA and RCGP annual conferences, and site visits were conducted to enhance mutual understanding. The outcomes are summarized in this report.

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.

Methods: Radiological parameters were extracted from the whole lateral radiographs. Patients were divided into two groups: the ASD group (segmental kyphosis of ≥10º, and/or a ≥50% loss of disc height, and/or ≥3 mm of anteroposterior translation) and the non-ASD group. Results: All 112 included patients underwent PLIF for lumbar degenerative diseases. The minimum follow-up period was 2 years, with an average follow-up time of 63.6 months. Fifty-two patients (46.4%) were classified into the ASD group and of these, 13 required reoperation due to failure of conservative treatment. Patients with ASD exhibited significantly more caudal and posterior inflection vertebrae (IV), while the lumbar apical vertebra was significantly more caudal immediately after surgery. The IV position was identified as a significant risk factor for ASD, and the ASD incidence was significantly higher in the group where IV ≤5 (L1 vertebral body) than in the group where IV ≥5.5 (T12–L1 disc) (69.0% vs. 38.6%). Conclusions The IV position is a significant risk factor for ASD development. Although it is difficult to control intraoperative IV levels, we note a high risk of ASD in patients with IV lower than T12–L1.

Objectives: Locomotive syndrome stage 3 (LS3), which has been established recently, may imply a greater need for care than LS stage 0 (LS0), LS stage 1 (LS1), and LS stage 2 (LS2). The relationship between LS3 and long-term care in Japan is unclear. Therefore, this study aimed to examine this relationship. Methods: A total of 531 patients (314 women and 217 men; mean age, 75 years) who were not classified as requiring long-term care and underwent musculoskeletal examinations in 2012 were grouped according to their LS stage. Group L comprised patients with LS3 and Group N comprised those with LS0, LS1, and LS2. We compared these groups according to their epidemiology results and long-term care requirements from 2013 to 2018. Results: Fifty-nine patients (11.1%) were diagnosed with LS3. Group L comprised more patients (50.8%) who required long-term care than Group N (17.8%) (P < 0.001). Group L also comprised more patients with vertebral fractures and knee osteoarthritis than Group N (33.9% vs 19.5% [P = 0.011] and 78% vs 56.4% [P < 0.001], respectively). A Cox proportional hazards model and Kaplan–Meier analysis revealed a significant difference in the need for nursing care between Groups L and N (log-rank test, P < 0.001; hazard ratio, 2.236; 95% confidence interval, 1.451–3.447). Conclusions Between 2012 and 2018, 50% of patients with LS3 required nursing care. Therefore, LS3 is a highrisk condition that necessitates interventions. Approaches to vertebral fractures and osteoarthritis of the knee could be key.

Methods: This retrospective study includes 295 corrective surgery patients with ASD. Subjects were divided into two groups after propensity age matching analysis: cranial malalignment (McGS <−8 or >13) and normal cranial alignment (−8≤ McGS ≤13). Lumbar lordosis (LL), pelvic tilt (PT), TK, cervical lordosis (CL), and sagittal vertical axis (SVA) were evaluated between the two groups. Results: SVA (95–56 mm) and PT (34°–25°) decreased and LL (19°–41°) increased 2 years after surgery (p <0.05), but McGS (−1.1° to −0.5°) and CL (21°–19°) did not change. Conversely, in the group with cranial malalignment, SVA (120–64 mm), PT (35°–26°), and LL (12°–41°) showed similar results to the normal cranial parameter group 2 years after surgery, but in contrast, McGS (−13° to −2°) and CL (24°–18°) improved significantly. Conclusions Severe ASD adversely affects to maintain horizontal gaze but can be improved by spinal corrective surgery.

Methods: Adult volunteers aged over 50 years were included in the study after participating in the screening program. Characteristic data and standing radiographic parameters were assessed. A propensity score model was established with adjustments for age and sex after a preliminary analysis, and cases were divided into DLS (Cobb angle >10°) and non-DLS (Cobb angle ≤10°) groups. Results: There were significant differences in age, sex, C2 sagittal vertical axis (C2-SVA), C7-SVA, T1 pelvic angle (TPA), lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), PI minus LL (PI–LL), knee angle, ankle angle, pelvic shift, C7-center sacral vertical line, L4 tilt, femur-tibia angle, and hip-knee-ankle angle (all p <0.05) using a preliminary analysis of 261 cases (75 DLS and 186 non-DLS). A one-to-one propensity score-matched analysis was used after 70 pairs of cases were selected. There were no significant differences in the characteristic data for lower extremity parameters. There were still significantly higher values of C2-SVA, TPA, PI, PT, and PI–LL in DLS group than in non-DLS group (all p <0.05). Conclusions This study showed an important relationship between DLS and sagittal spinal deformity. However, DLS was not associated with the sagittal and coronal lower extremity alignments.

Methods: We examined the data of AIS patients with Lenke type 1 curves who underwent posterior fusion surgery in a retrospective manner. PSI was defined as a 2-year postoperative absolute radiographic shoulder height (RSH) of ≥2 cm. Patients were divided into two groups based on the presence of PSI and the level of their upper instrumented vertebra (UIV) (UIV at T2 or T3 [U-UIV] or UIV below T3 [L-UIV]). The radiographic parameters and clinical outcomes were compared, and the cutoff values of risk factors were identified by multivariate analysis. Results: Of 104 patients, 21 (20.2%) had left shoulder elevation PSI. The PSI group had a significantly greater preoperative RSH (−5.1 mm vs. −14.3 mm) and main thoracic (MT) curve correction rate (77.3% vs. 69.1%) than the non-PSI group. The PSI incidence did not differ between the U-UIV and L-UIV groups. Multivariate analysis identified preoperative RSH and the MT curve correction rate as independent risk factors for PSI. The receiver operating characteristic curve analysis identified the preoperative RSH cutoff value as −6.5 mm and MT curve correction rate cutoff value as 76.9%. Conclusions Even in AIS patients with Lenke type 1 curves, the incidence of PSI was relatively high (20.2%). Patients with preoperative lower right shoulder elevation (i.e., RSH >−6.5 mm) had a higher risk of PSI regardless of UIV level when the MT curve showed a higher correction rate (i.e., correction rate >76.9%).

Methods: We retrospectively reviewed the medical records of 404 patients who underwent corrective fusion surgery for ASD with a minimum 2-year follow-up. We studied cases of reoperation for postoperative rod fractures and investigated surgical procedure, intraoperative findings, clinical course, and rod refracture following revision surgery. Results: Rod fracture was observed in 88 patients (21.8%). Fifty-three patients (average age, 68.3 years; average blood loss, 502.2 mL [% estimated blood volume=16.4%]; and operation time, 203.3 minutes) who suffered from a rod fracture at an average of 28.3 months after the primary operation underwent reoperation. Surgical invasiveness had no significant differences in total or partial rod replacement; however, the procedures with and without an anterior bone graft significantly differed. The replaced rod refractured at an average of 35.3 months after the revision surgery of five patients. The rod also refractured at a level outside multiple rods in two patients and with traumatic episodes in three patients. Three patients had bone grafts in the anterior column. Conclusions Revision surgery involving a multirod with a posterior-only approach for a rod fracture that occurred after ASD was performed successfully. Bone grafting in the anterior column is unnecessary for patients without massive bone defects.