Instrumentation failure following pediatric spine deformity growth-sparing surgery using traditional growing rods or vertical expandable prosthetic titanium ribs.

BACKGROUND: Instrumentation failure (IF) is a major complication associated with growth-sparing surgery for pediatric spinal deformities; however, studies focusing on IF following each surgical procedure are lacking. We aimed to evaluate the incidence, timing, and rates of unplanned return to the operating room (UPROR) associated with IF following each surgical procedure in growth-sparing surgeries using traditional growing rods (TGRs) and vertical expandable prosthetic titanium ribs (VEPTRs). METHODS: We reviewed 1,139 surgical procedures documented in a Japanese multicenter database from 2015 to 2017. Of these, 544 TGR and 455 VEPTR procedures were included for evaluation on a per-surgery basis. IF was defined as the occurrence of an implant-related complication requiring revision surgery. RESULTS: The surgery-based incidences of IF requiring revision surgery in the TGR and VEPTR groups were 4.3% and 4.0%, respectively, with no significant intergroup difference. Remarkably, there was a negative correlation between IF incidence per surgical procedure and the number of lengthening surgeries in both groups. In addition, rod breakage in the TGR group and anchor-related complications in the VEPTR group tended to occur relatively early in the treatment course. The surgery-based rates of UPROR due to IF in the TGR and VEPTR groups were 2.0% and 1.5%, respectively, showing no statistically significant difference. CONCLUSIONS: We found that IF, such as anchor related-complications and rod breakage, occurs more frequently earlier in the course of lengthening surgeries. This finding may help in patient counseling and highlights the importance of close postoperative follow-up to detect IF and improve outcomes.

Conditional deletion of IκBζ in hematopoietic cells promotes functional recovery after spinal cord injury in mice.

BACKGROUND: Transcription factor protein IκBζ (encoded by the Nfkbiz gene) regulates nuclear factor-κB (NF-κB) and is involved in the pathophysiology of various inflammatory diseases. However, the role of IκBζ in secondary damage following spinal cord injury (SCI) remains to be determined. Here, we investigated the effect of IκBζ expressed in hematopoietic cells on the progression of secondary damage and functional recovery after SCI. METHODS: We used conditional IκBζ-knockout mice (Mx1-Cre;Nfkbizfl/f) to examine the role of IκBζ in hematopoietic cells after SCI. Contusion SCI was induced using a force of 60 kdyn. The recovery of locomotor performance was evaluated using the nine-point Basso Mouse Scale (BMS) until 42 days post-injury. Expression patterns of inflammatory cytokines and chemokines were examined by quantitative real-time PCR or proteome array analysis. Bone marrow transplantation (BMT) was performed to eliminate the effect of IκBζ deletion in non-hematopoietic cells. RESULTS: Mx1-Cre;Nfkbizfl/fl mice had significantly improved locomotor function compared with wild-type (WT) mice. The mRNA expression of Nfkbiz in WT mice peaked at 12 h after SCI and then decreased slowly in both the spinal cord and white blood cells. In situ hybridization showed that Nfkbiz mRNA was localized in cell nuclei, including macrophage-like cells, in the injured spinal cord of WT mice at 1 day after SCI. Compared with WT mice, Mx1-Cre;Nfkbizfl/fl mice had significantly increased mRNA expressions of interleukin (Il)-4 and Il-10 in the injured spinal cord. In addition, Mx1-Cre;Nfkbizfl/fl mice had significantly higher protein levels of granulocyte-macrophage colony-stimulating factor and C-C motif chemokine 11 compared with WT mice. BMT from Mx1-Cre;Nfkbizfl/fl mice into WT mice improved functional recovery after SCI compared with control mice (WT cells into WT mice). CONCLUSIONS: IκBζ deletion in hematopoietic cells improved functional recovery after SCI, possibly by shifting the inflammatory balance towards anti-inflammatory and pro-regenerative directions.

Trends in cervical laminoplasty and 30-day postoperative complications: 10-year results from a retrospective, multi-institutional study of 1095 patients.

PURPOSE: This study aimed to investigate the recent 10-year trends in cervical laminoplasty and 30-day postoperative complications. METHODS: This retrospective multi-institutional cohort study enrolled patients who underwent laminoplasty for cervical spondylotic myelopathy (CSM) or ossification of the posterior longitudinal ligament. The primary outcome was the occurrence of all-cause 30-day complications. Trends were investigated and compared in the early (2008-2012) and late (2013-2017) periods. RESULTS: Among 1095 patients (mean age, 66 years; 762 [70%] male), 542 and 553 patients were treated in the early and late periods, respectively. In the late period, patients were older at surgery (65 years vs. 68 years), there were more males (66% vs. 73%), and open-door laminoplasty (50% vs. 69%) was the preferred procedure, while %CSM (77% vs. 78%) and the perioperative JOA scores were similar to the early period. During the study period, the rate of preservation of the posterior muscle-ligament complex attached to the C2/C7-spinous process (C2, 89% vs. 93%; C7, 62% vs. 85%) increased and the number of laminoplasty levels (3.7 vs. 3.1) decreased. While the 30-day complication rate remained stable (3.9% vs. 3.4%), C5 palsy tended to decrease (2.4% vs. 0.9%, P = 0.059); superficial SSI increased significantly (0% vs. 1.3%, P = 0.015), while the decreased incidence of deep SSI did not reach statistical significance (0.6% vs. 0.2%). CONCLUSIONS: From 2008 to 2017, there were trends toward increasing age at surgery and surgeons' preference for refined open-door laminoplasty. The 30-day complication rate remained stable, but the C5 palsy rate halved.

Deep learning-based prediction model for postoperative complications of cervical posterior longitudinal ligament ossification.

PURPOSE: Postoperative complication prediction helps surgeons to inform and manage patient expectations. Deep learning, a model that finds patterns in large samples of data, outperform traditional statistical methods in making predictions. This study aimed to create a deep learning-based model (DLM) to predict postoperative complications in patients with cervical ossification of the posterior longitudinal ligament (OPLL). METHODS: This prospective multicenter study was conducted by the 28 institutions, and 478 patients were included in the analysis. Deep learning was used to create two predictive models of the overall postoperative complications and neurological complications, one of the major complications. These models were constructed by learning the patient's preoperative background, clinical symptoms, surgical procedures, and imaging findings. These logistic regression models were also created, and these accuracies were compared with those of the DLM. RESULTS: Overall complications were observed in 127 cases (26.6%). The accuracy of the DLM was 74.6 ± 3.7% for predicting the overall occurrence of complications, which was comparable to that of the logistic regression (74.1%). Neurological complications were observed in 48 cases (10.0%), and the accuracy of the DLM was 91.7 ± 3.5%, which was higher than that of the logistic regression (90.1%). CONCLUSION: A new algorithm using deep learning was able to predict complications after cervical OPLL surgery. This model was well calibrated, with prediction accuracy comparable to that of regression models. The accuracy remained high even for predicting only neurological complications, for which the case number is limited compared to conventional statistical methods.

Standard radiographic values for the acetabulum in Japanese adolescents: a cross-sectional study.

BACKGROUND: Most previous reports of normal acetabular radiographic values focused on adults or elderly people. Recent reports have described premature hip osteoarthritis in adolescents not caused by acetabular dysplasia. In addition, there is a certain failure rate of surgical treatment for young patients with borderline acetabular dysplasia. Accurate indices for treatment of adolescent hips are unclear because standard measurement values of the adolescent acetabulum have not been reported. METHODS: This cross-sectional study involved 552 Japanese adolescents aged 12-18 years who had scoliosis or suspected scoliosis and asymptomatic hips. All persons underwent plain standing anteroposterior whole-spine radiography, and measurements were obtained using the pelvic part of the radiograph. We excluded persons who were unable to correctly perform measurements because of conditions such as pelvic rotation or lateral inclination and persons in whom closure of the triradiate cartilage or closure of the secondary ossification centers of the acetabulum had not yet occurred. In 1101 hips, we measured the lateral center-edge angle (LCEA), Tönnis angle, Sharp angle, acetabular head index (AHI), lateral subluxation (LS), vertical subluxation (VS), and peak-to-edge distance (PED). We evaluated the correlation coefficient and coefficient of determination between each parameter and age, height, body weight, and body mass index (BMI) and assessed the intra- and inter-rater reliability of each radiographic parameter. RESULTS: Among all hips, the mean of each parameter was as follows: LCEA, 27.9° ± 4.8°; Tönnis angle, 5.0° ± 3.7°; Sharp angle, 44.1° ± 3.1°; AHI, 82.1% ± 5.5%; LS, 5.4 ± 1.4 mm; VS, 0.3 ± 1.2 mm; and PED, 14.0 ± 2.3 mm. The correlation between each parameter and age, height, body weight, and BMI was considerably low. Intra- and inter-rater reliability was moderate or good for almost all parameters. CONCLUSIONS: The values for each radiographic parameter of the acetabulum in this study are considered standard for the adolescent acetabulum without age-related changes. Some parameters differ slightly from the normal values for adults or elderly people in previous reports; thus, we suggest careful evaluation of these parameters for adolescents.

Epidemiology of distal radius fracture: a regional population-based study in Japan.

BACKGROUND: Distal radius fracture (DRF) is very common worldwide. In particular, aging countries have numerous patients with DRF, resulting in an urgent need for active preventive measures. As few epidemiological studies have investigated DRF in Japan, we aimed to identify the epidemiological characteristics of patients of all ages with DRF in Japan. METHODS: This descriptive epidemiologic study analyzed data obtained from clinical information of patients diagnosed with DRF from January 1, 2011, to December 31, 2020, at a prefectural hospital in Hokkaido, Japan. We calculated the crude and age-adjusted annual incidences of DRF and described the age-specific incidence, injury characteristics (injury location and cause, seasonal differences, and fracture classification), and 1- and 5-year mortality rates. RESULTS: A total of 258 patients with DRF were identified, of which 190 (73.6%) were female and the mean age (standard deviation) was 67.0 (21.5) years. The crude annual incidence of DRF ranged from 158.0 to 272.6 per 100,000 population/year, and the age-adjusted incidence among female patients demonstrated a significant decreasing trend during 2011-2020 (Poisson regression analysis; p = 0.043). The age-specific incidence differed by sex, with peaks at 10-14 years for males and 75-79 years for females. The most common cause of injury was a simple fall in patients > 15 year of age and sports injuries in patients ≤ 15 years of age. DRFs were most frequently sustained outdoors and were more common in the winter season. In patients > 15 years of age, the proportions of AO/OTA fracture types A, B, and C were 78.7% (184/234), 1.7% (4/234), and 19.6% (46/234), respectively, and 29.1% (68/234) of patients received surgical treatment for DRF. The 1- and 5-year mortality rates were 2.8% and 11.9%, respectively. CONCLUSIONS: Our findings were mostly consistent with previous global studies. Although the crude annual incidence of DRF was relatively high because of recent population aging, the age-adjusted annual incidence among female patients showed a significant decreasing trend during this decade.

Postoperative clinical outcomes for kinematically, restricted kinematically, or mechanically aligned total knee arthroplasty: a systematic review and network meta-analysis of randomized controlled trials.

BACKGROUND: Mechanically aligned total knee arthroplasty (MATKA) is a well-established procedure. Kinematically aligned TKA (KATKA) has been proposed to restore and preserve pre-arthritic knee anatomy. However, normal knee anatomy varies widely, and there have been concerns regarding restoring unusual anatomy. Accordingly, restricted KATKA (rKATKA) was introduced to reproduce constitutional knee anatomy within a safe range. This network meta-analysis (NMA) aimed to evaluate the clinical and radiological outcomes of the surgeries. METHODS: We performed a database search on August 20, 2022, which included randomized controlled trials (RCTs) comparing any two of the three surgical TKA techniques for knee osteoarthritis. We conducted a random-effects NMA within the frequentist framework and evaluated confidence in each outcome using the Confidence in Network Meta-Analysis tool. RESULTS: Ten RCTs with 1,008 knees and a median follow-up period of 1.5 years were included. The three methods might result in little to no difference in range of motion (ROM) between methods. In patient-reported outcome measures (PROMs), the KATKA might result in a slight improvement compared with the MATKA (standardized mean difference, 0.47; 95% confidence interval [CI], 0.16-0.78; very low confidence). There was little to no difference in revision risk between MATKA and KATKA. KATKA and rKATKA showed a slight valgus femoral component (mean difference [MD], -1.35; 95% CI, -1.95-[-0.75]; very low confidence; and MD, -1.72; 95% CI, -2.63-[-0.81]; very low confidence, respectively) and a slight varus tibial component (MD, 2.23; 95% CI, 1.22-3.24; very low confidence; and MD, 1.25; 95% CI, 0.01-2.49; very low confidence, respectively) compared with MATKA. Tibial component inclination and hip-knee-ankle angle might result in little to no difference between the three procedures. CONCLUSIONS: KATKA and rKATKA showed similar ROM and PROMs and a slight variation in the coronal component alignment compared with MATKA. KATKA and rKATKA are acceptable methods in short- to mid-term follow-up periods. However, long-term clinical results in patients with severe varus deformity are still lacking. Surgeons should choose surgical procedures carefully. Further trials are warranted to evaluate the efficacy, safety, and subsequent revision risk.

Suture Augmentation Does Not Change Biomechanical Properties and Histological Remodeling of Tendon Graft in Anterior Cruciate Ligament Reconstruction: A Study in a Porcine Model.

PURPOSE: To evaluate the initial safety of the combined use of ultra-high molecular weight polyethylene (UHMWPE) sutures for suture augmentation (SA) in a porcine ACL reconstruction model and examine whether the procedure can affect the anterior knee laxity and structural properties of the tendon graft itself, influence histological remodeling, and cause a foreign body-induced inflammation. METHODS: Ten pigs were divided into SA and non-SA Groups to undergo ACL reconstruction using an autologous semitendinosus tendon with and without SA, respectively. At 12 weeks postoperatively, the tibial fixation of the grafted tendon and SA was removed, and the anterior knee laxity and structural characteristics of the grafted tendon were evaluated for mechanical testing. Histological evaluation, including the ligament tissue maturation index (LTMI) score and the presence or absence of foreign-body reaction, was evaluated. RESULTS: There was no significant difference in anterior laxity between the two groups (SA Group, 1.19 ± 0.78 mm; non-SA Group, 1.08 ± 0.42 mm; P = 1). There were no significant differences in maximum load failure, yield strength, stiffness, elongation at failure, and the LTMI score between the two groups (P = 0.31, 1, 1, 1, and 0.24, respectively). All grafted tendons showed no foreign-body reactions. CONCLUSION: Suture augmentation did not have significant effect on the anterior knee laxity and the structural properties of the grafted tendon, interfere with histological remodeling, or cause foreign body-induced reactions. CLINICAL RELEVANCE: The results of our study may lay the foundation for further clinical studies to verify the usefulness of ACL reconstruction with SA.

AO/OTA 31A3 fractures and postoperative complications in older patients.

BACKGROUND: AO/OTA 31A3 fractures (A3 fractures) have risk for postoperative complications with major impact on morbidity and mortality. For older patients, limited information is available for factors associated with postoperative complications. We aimed to assess factors associated with postoperative complications after surgery using cephalomedullary nails. METHODS: A retrospective cohort study was conducted using the information on patients aged ≥65 years who underwent surgery using cephalomedullary nails for trochanteric fractures due to low-energy trauma in three hospitals. Postoperative complications were diagnosed when patients were identified as nonunion, cutout of lag screw, or nail breakage. First, we compared differences including age, sex, body mass index, American Society of Anesthesiologists physical status classification system, preoperative waking ability, fracture type, nail length, neck shaft angle, reduction method, reduction quality and tip apex distance between patients with and without postoperative complications. Second, multivariable logistic regression analysis was employed to assess factors associated with postoperative complications resulting from A3 fractures. RESULTS: Among 120 patients with A3 fractures, postoperative complications were identified in 12 patients (10.0%). Postoperative complications were significantly more likely to develop among patients with poor reduction quality (adjusted odds ratio [95% confidence interval], 35.0 [4.43-275.9]) and a tip-apex distance ≥25 mm (16.4 [1.92-140.3]). CONCLUSIONS: These findings suggest that surgeons should aim to perform appropriate postoperative reduction and to prevent postoperative complications when using a cephalomedullary nail for A3 fractures among older patients.

Younger age is a significant factor for poorer adherence in fracture patients who received low-intensity pulsed ultrasound: A retrospective study.

BACKGROUND: The factors for poor adherence to therapy in patients with postoperative fracture who are treated with low-intensity pulsed ultrasound remain unknown. Therefore, we designed a retrospective cohort study to determine the various factors for poorer adherence to therapy in patients with postoperative fracture who were treated with low-intensity pulsed ultrasound therapy. METHODS: We retrospectively analyzed the data of postoperative patients who underwent low-intensity pulsed ultrasound after fracture surgery from January 2010 to May 2019. The patients were categorized into two groups as follows: group G, including those with a good adherence rate (>72%), and group P, including those with a poor adherence rate (<72%). Factors, such as age, sex, how the rental cost of low-intensity pulsed ultrasound was paid (by the patients themselves or by the insurance company), living (alone or with someone), insurance claim item (fractures within 3 weeks after osteosynthesis or delayed or non-union fractures), low-intensity pulsed ultrasound device-type (earlier- or next-generation), duration of low-intensity pulsed ultrasound use, fracture site (upper or lower limb), frequency of hospital visits (regular or irregular), and employment status (employed/unemployed) were compared between groups G and P. RESULTS: In total, 96 patients (74 and 22 patients in groups G and P, respectively) who underwent low-intensity pulsed ultrasound were included in the study. Univariate analysis revealed that younger patients (P < 0.001) and patients who did not regularly visit the hospital (P = 0.024) were more likely to have poorer adherence to therapy. Multiple logistic regression analysis revealed that age was the only independent, pertinent factor for poorer adherence to therapy (odds ratio, 8.570; 95% confidence interval, 2.770-26.50; P < 0.001), with a cutoff value of 41 years. CONCLUSIONS: Younger age is a significant factor for poorer adherence in patients undergoing low-intensity pulsed ultrasound therapy.

Combination of radiographic apparent bone gap and nonunion risk determination score improves accuracy of prediction of tibial shaft delayed union.

BACKGROUND: There is a need for a novel therapeutic strategy for an earlier prediction of long bone union failure as compared to previous methodologies. This study aimed to determine whether a combination of two diagnostic tools would result in a more accurate diagnosis of delayed union. METHODS: The inclusion criteria were as follows: patients with tibial shaft fracture who underwent treatment with intramedullary nailing (IMN) as definitive internal fixation (IF). The study included a total of 114 patients with 116 tibial shaft fractures treated with IMN as definitive IF. Radiographic apparent bone gap (RABG) and nonunion risk determination score (NURDS) can be used to predict nonunion. However, this study aimed to determine whether combination of RABG and NURDS could help deduce a more accurate prediction of delayed union. RESULTS: The union rate was found to be 85% (99 fractures), the delayed union rate was found to be 15% (17 fractures), and the rate of nonunion requiring additional surgical intervention was estimated to be 4% (5 out of the 17 delayed union cases). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of RABG were found to be 82.3%, 76.0%, 36.8%, and 96.2%, respectively, when an RABG cutoff value of 5.0 mm was applied to our patient cohort. The sensitivity, specificity, PPV, and NPV of NURDS were found to be 47.1%, 82.0%, 30.8%, and 90.1%, respectively, when a NURDS cutoff value of 8.0% was applied to our patient cohort. When RABG and NURDS were above their respective cutoff values, the sensitivity and PPV were estimated to be 90.0% and 56.3%, respectively. When RABG and NURDS were below their respective cutoff values, the specificity and NPV were estimated to be 90.1% and 98.5%, respectively. CONCLUSIONS: The combination of RABG and NURDS evaluation immediately after surgery helps surgeons identify patients who are at a high risk of delayed union, facilitating careful monitoring of these patients and consideration of additional treatments.

Ossification of the anterior longitudinal ligament affects the severity and distribution of neurological deficits following spinal cord injury without radiological abnormality.

BACKGROUND: The incidence of spinal cord injury without radiological abnormality (SCIWORA) is increasing among older adults in developed countries. SCIWORA is commonly associated with ossification of the spinal ligament, specifically the ossification of the posterior longitudinal ligament (OPLL) and ossification of the anterior longitudinal ligament (OALL). OALL induces segmental spinal fusion and alters the biomechanical properties of the cervical spine; however, whether OALL modulates the severity of SCIWORA remains unknown. This study aimed to investigate the influence of OALL on the severity and distribution of neurological deficits following SCIWORA. METHODS: This retrospective study included 122 patients with SCIWORA who were admitted to our hospital from April 2008 to March 2022. The neurological function of all the included patients was assessed via the American Spinal Injury Association (ASIA) Impairment Scale (AIS) at admission. Magnetic resonance imaging (MRI) and computed tomography were performed within 48 h of trauma. Central cord syndrome (CCS) was defined as the upper-extremity ASIA motor score being at least 10 points lesser than the lower-extremity motor score. RESULTS: The study included 122 patients with a mean age of 65.1 years. Comparing mild (AIS grades C or D) and severe (AIS grades A or B) neurological deficits revealed that the former was independently associated with ground-level falls, OALL, and absence of prevertebral T2 high-intensity area on MRI. Although 39% of patients with SCIWORA exhibited OPLL as an etiology of cervical stenosis, OPLL demonstrated no significant effect on the severity of neurological deficits. CCS occurrence was independently associated with OALL and a larger cross-sectional cord area on MRI. Patients with OALL had significantly higher lower-extremity ASIA motor scores than those without OALL. CONCLUSIONS: OALL was significantly associated with mild neurological deficits in the lower extremities and with the occurrence of CCS after SCIWORA.

Radiation exposure in pediatric patients with early onset scoliosis: A longitudinal single-center study.

BACKGROUND: There is no consensus regarding the acceptable level of medical radiation exposure in patients with early-onset scoliosis. This study aimed to quantify radiation exposure in these patients and investigate factors associated with high exposure. METHODS: Patients with early-onset scoliosis who received care for their spine deformity and other comorbidities in our institution were retrospectively reviewed. Cumulative radiation exposure and total number of imaging studies were recorded. Patients with ≥30 mSv exposure were classified as high exposure and analyzed to clarify factors associated with high exposure. RESULTS: Thirty-five patients were included for analysis. The etiology of scoliosis was idiopathic in 8 patients, congenital in 7, syndromic in 8, and neuromuscular in 12. Fifteen patients underwent 19 spinal surgeries. The types of operation performed were definitive fusion (n = 12), vertebrectomy for hemivertebra (n = 2), growing rod (n = 1), lengthening (n = 3), and revision/partial implant removal (n = 1). The mean cumulative radiation dose was 22.3 mSv (range, 2.5-94.5 mSv). Spine radiography and computed tomography combined accounted for 15.0 mSv (range, 2.4-52.5 mSv, 67.3% of the mean cumulative dose). The mean radiation dose was significantly higher in patients who underwent spinal surgery than in those who did not (31.2 mSv vs. 15.6 mSv). The high-exposure group comprised 10 patients (1 idiopathic, 1 congenital, 5 syndromic, and 3 neuromuscular scoliosis) and 8 underwent 11 spinal operations. Among 8 patients who underwent spinal surgery, the cumulative radiation dose for spine was ≥30 mSv and spine computed tomography was performed an average of 4.0 times. CONCLUSIONS: Nearly one-third of patients with early-onset scoliosis and half of patients who underwent spinal surgery had >30 mSv radiation exposure due to multiple computed tomography. Medical radiation exposure and associated cancer risk should be considered when treating these patients.

Efficacy of fracture stem in reverse shoulder arthroplasty for 3- or 4-part proximal humerus fractures.

BACKGROUND: This study compared the clinical results of fracture stems and conventional stems using the same glenoid component in reverse shoulder arthroplasty for proximal humerus fractures in the elderly. METHODS: This retrospective study included 35 patients who underwent Grammont-type reverse shoulder arthroplasty for proximal humerus fractures from 2014 to 2020. The average age at surgery was 79.2 (range, 65-92) years, with 33 female shoulders. Fracture types per Neer classification were 3-part fracture, 4-part fracture, in 13 and 22 shoulders, respectively. The final follow-up period was 35 (range, 24-81) months. The Constant score, American Shoulder and Elbow Surgeons score, shoulder range of motion, and healing of greater tuberosities at the final follow-up of AEQUALIS™ REVERSED (Conventional stem group: n = 15) and AEQUALIS™ REVERSED FX (Fractured stem group: n = 20) were retrospectively investigated. RESULTS: There were no statistically significant differences in age at surgery, sex, body mass index, fracture type, waiting time from injury to surgery, or preoperative general condition between the groups. The Constant and American Shoulder and Elbow Surgeons scores of the fractured stem group were significantly higher than those of the conventional stem group (P = 0.038 and P = 0.023, respectively). The anterior elevation and external rotation at the side of the fractured stem group also showed significantly higher values than those of the conventional stem group (fractured stem group vs. conventional stem group: anterior elevation 127° ± 25° vs. 105° ± 35°, P = 0.041; external rotation 28° ± 13° vs. 13° ± 12°, P = 0.015). The greater tuberosity healing rate was 46.7% (7/15) in the conventional stem group and 85.0% (17/20) in the fractured stem group (P＝0.027). CONCLUSIONS: The findings suggest that use of a fracture-specific stem rather than a conventional stem in Grammont-type reverse shoulder arthroplasty for proximal humerus fractures improves tuberosity healing, postoperative range of motion, and clinical scores.

Morphological and histological evaluation of the tendon-bone junction in porcine shoulders to create a rotator cuff tear and repair model.

BACKGROUND: This study aimed to morphologically and histologically examine whether pig is useful as models for rotator cuff tear (RCT). METHODS: The morphology of the scapula and humerus bones was evaluated by taking X-ray and three-dimensional computed tomography (3D CT) scans of the right shoulders of five female pigs (age: 4 months). The rotator cuff (RC) footprint at the humeral insertion of these was observed and its shape was measured. Next, they underwent general anesthesia and an acute rotator cuff tear/rotator cuff repair (RCT/RCR) model was created using a deltoid split approach. Four weeks after surgery, the animals were euthanized, the shoulder joints were harvested, and the repaired RC was evaluated by hematoxylin and eosin staining and toluidine blue staining. RESULTS: The scapula of the pig had a vestigial acromion, in contrast to that in humans. The supraspinatus and infraspinatus tendons were connected so as to overlap each other and attached to the postero-superior part of the greater tuberosity. These tendons were located extra-articularly, separate from the joint capsule. The average antero-posterior length of the foot print was 17.4 ± 0.7 mm on the medial margin and 19.1 ± 2.2 mm on the lateral margin. The maximum medial-to-lateral width of it was 5.1 ± 0.5 mm. In all RCT/RCR models at 4 weeks after surgery, the repaired RC compound tendon was visually confirmed to be continuous with the footprint. Histologically, it was confirmed that regeneration of the four-layer structure of the bone-tendon junction had occurred. CONCLUSION: Porcine supraspinatus and infraspinatus attachment to the greater tuberosity have a structure similar to that of sheep and dogs, which is advantageous for creating the RCT/RCR model. It might be used for future in vivo studies of shoulder joint diseases. THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE: Pigs could potentially serve as a viable model for rotator cuff tears.

Japanese Orthopaedic Association (JOA) clinical practice guidelines on the management of lumbar spinal stenosis, 2021 - Secondary publication.

BACKGROUND: The Japanese Orthopaedic Association (JOA) guideline for the management of lumbar spinal stenosis (LSS) was first published in 2011. Since then, the medical care system for LSS has changed and many new articles regarding the epidemiology and diagnostics of LSS, conservative treatments such as new pharmacotherapy and physical therapy, and surgical treatments including minimally invasive surgery have been published. In addition, various issues need to be examined, such as verification of patient-reported outcome measures, and the economic effect of revised medical management of patients with lumbar spinal disorders. Accordingly, in 2019 the JOA clinical guidelines committee decided to update the guideline and consequently established a formulation committee. The purpose of this study was to describe the formulation we implemented for the revision of the guideline, incorporating the recent advances of evidence-based medicine. METHODS: The JOA LSS guideline formulation committee revised the previous guideline based on the method for preparing clinical guidelines in Japan proposed by the Medical Information Network Distribution Service in 2017. Background and clinical questions were determined followed by a literature search related to each question. Appropriate articles based on keywords were selected from all the searched literature. Using prepared structured abstracts, systematic reviews and meta-analyses were performed. The strength of evidence and recommendations for each clinical question was decided by the committee members. RESULTS: Eight background and 15 clinical questions were determined. Answers and explanations were described for the background questions. For each clinical question, the strength of evidence and the recommendation were both decided, and an explanation was provided. CONCLUSIONS: The 2021 clinical practice guideline for the management of LSS was completed according to the latest evidence-based medicine. We expect that this guideline will be useful for all medical providers as an index in daily medical care, as well as for patients with LSS.

The influence of COVID-19 epidemic on the number of orthopaedic surgeries in Japan.

BACKGROUND: There is limited data on the impact of COVID-19 epidemic on the number of orthopaedic surgeries in Japan. METHODS: We conducted a nationwide hospital survey asking for the monthly number of orthopaedic surgeries performed at each facility from January 2019 to June 2021. Those facilities that had performed at least 100 surgeries in 2019 were included for analyses. The facilities were further grouped by prefecture and by hospital characteristics. A brief health economic evaluation was also performed. Risk ratios were compared using univariate analyses with P < 0.05 considered statistically significant. RESULTS: Questionnaire was sent to 1988 hospitals with 1671 hospitals (84%) responding. The survey data indicated a total number of orthopaedic surgeries decreased in 2020 compared to 2019 (1,061,541 vs 1,119,955 P < 0.01), and also for the first six months of 2021 compared to the same period in 2019 (530,388 vs 550,378 P < 0.01). In 2020, over 50% of all facilities in nearly all of the prefectures saw a decline in surgical procedures. The risk of incurring more than a 25% decease in the number of surgeries was significantly higher in 2020 for class I designated medical institutions compared to those that were not designated for any types of infectious diseases among the institutions with a tertiary emergency medical center in 2020 (crude risk ratio 2.9: 95% CI 1.2-7.4, p = 0.02) and in 2021 (crude risk ratio 4.7: 95% CI 1 0.9-12.1, p < 0.01). The estimated total nationwide decrease of revenue were in the range of approximately ¥29.2 to ¥116.8 billion per year for orthopaedic surgeries alone. CONCLUSION: There was a statistically significant decrease in the number of orthopaedic surgeries in Japan. The magnitude of the decline varied by prefectures and hospital characteristics, with the greater impact imposed on medical institutions with higher classification functions. The estimated immediate health economic impact was sizable.

Minimally invasive plate osteosynthesis with locking plate for metastatic humeral fractures.

BACKGROUND: Limited reports have examined the outcomes and complications of minimally invasive plate osteosynthesis (MIPO) with a locking plate (LP) in metastatic humeral fractures. Therefore, this study aimed to evaluate the effectiveness of MIPO in the treatment of metastatic humeral fractures. METHODS: Patients who underwent MIPO for metastatic humeral fractures were included in this study. Data on patient demographics, new Katagiri score, operative time, amount of blood loss, bone union rate, range of motion (ROM) of the shoulder and elbow, and perioperative complications were obtained. RESULTS: Twelve patients (seven men and five women) with 14 fractures were included in this study. The median operative time was 92.6 ± 28.9 min (range, 57-175 min) and the median amount of intraoperative blood loss was 106.1 ± 109.5 g (range, 10-330 g). No patient required surgery-related transfusion. The median duration of acquisition of active elbow ROM of>100° and active shoulder flexion of >90° were 8.9 ± 6.6 days (range, 1-30 days) and 17.5 ± 13.0 days (range, 6-47 days), respectively. The mean follow-up period was 10.0 ± 9.0 months (range, 1-33 months). There were no complications, and no patient required any further surgery for the affected humerus until death. CONCLUSION: MIPO using an LP provided acceptable functional outcomes in advanced-stage cancer patients with metastatic humeral fractures during their limited lifetime.

A comparison between the femoral neck system and other implants for elderly patients with femoral neck fracture: A preliminary report of a newly developed implant.

BACKGROUND: Femoral neck system (FNS) is an implant for patients with femoral neck fracture. It has superior angular and rotatory stability; it is less invasive because of its established locking plate system. To the best of our knowledge, there are no studies yet concerning the clinical outcomes of elderly patients with femoral neck fracture who have been treated using the FNS. METHODS: Data of patients with femoral neck fracture aged >65 years and who had undergone internal fixation with the FNS and other implants were retrospectively analyzed in this study. The follow-up period was a minimum of six months between January 2006 and November 2020. In total, 52 patients were included in the clinical evaluations, using the FNS (group F) was 25 and using other implants (group O) was 27. Outcome measurements were surgical time, the amount of blood loss, union rate and the cases that underwent reoperation. RESULTS: The average surgical time in the group F was 42 ± 13 min (range: 26-83 min) and was shorter than that in the group O (53 ± 21 min, range: 13-111 min, P = 0.032). The average blood loss in the group F was calculated to 36 ± 25 g (range: 0-91 g), while it was 41 ± 40 g (range: 0-169 g) in group O. No significant difference among the groups. The union rate of the group F was 100%, and the reoperation rate of the group F was significantly less than that of the group O (0% vs 22%, P = 0.023). CONCLUSION: Internal fixation using the FNS can be an alternative option with shorter surgical time and lower reoperation rate for elderly patients with femoral neck fracture.

Formulation of Japanese Orthopaedic Association (JOA) clinical practice guideline for the management of low back pain- the revised 2019 edition.

BACKGROUND: The latest clinical guidelines are mandatory for physicians to follow when practicing evidence-based medicine in the treatment of low back pain. Those guidelines should target not only Japanese board-certified orthopaedic surgeons, but also primary physicians, and they should be prepared based entirely on evidence-based medicine. The Japanese Orthopaedic Association Low Back Pain guideline committee decided to update the guideline and launched the formulation committee. The purpose of this study was to describe the formulation we implemented for the revision of the guideline with the latest data of evidence-based medicine. METHODS: The Japanese Orthopaedic Association Low Back Pain guideline formulation committee revised the previous guideline based on a method for preparing clinical guidelines in Japan proposed by Medical Information Network Distribution Service Handbook for Clinical Practice Guideline Development 2014. Two key phrases, "body of evidence" and "benefit and harm balance" were focused on in the revised version. Background and clinical questions were determined, followed by literature search related to each question. Appropriate articles were selected from all the searched literature. Structured abstracts were prepared, and then meta-analyses were performed. The strength of both the body of evidence and the recommendation was decided by the committee members. RESULTS: Nine background and nine clinical qvuestions were determined. For each clinical question, outcomes from the literature were collected and meta-analysis was performed. Answers and explanations were described for each clinical question, and the strength of the recommendation was decided. For background questions, the recommendations were described based on previous literature. CONCLUSIONS: The 2019 clinical practice guideline for the management of low back pain was completed according to the latest evidence-based medicine. We strongly hope that this guideline serves as a benchmark for all physicians, as well as patients, in the management of low back pain.