TiNbSn stems with gradient changes of Young's modulus and stiffness reduce stress shielding compared to the standard fit-and-fill stems.

BACKGROUND: The difference between Young's moduli of the femur and the stem causes stress shielding (SS). TiNbSn (TNS) stem has a low Young's modulus and strength with gradient functional properties during the change in elastic modulus with heat treatment. The aim of this study was to investigate the inhibitory effect of TNS stems on SS and their clinical outcomes compared to conventional stems. METHODS: This study was a clinical trial. Primary THA was performed using a TNS stem from April 2016 to September 2017 for patients in the TNS group. Unilateral THA was performed using a Ti6Al4V alloy stem from January 2007 to February 2011 for patients in the control group. The TNS and Ti6Al4V stems were matched in shape. Radiographs were obtained at the 1- and 3-year follow-ups. Two surgeons independently checked the SS grade and appearance of cortical hypertrophy (CH). The Japanese Orthopaedic Association (JOA) scores before and 1 year after surgery were assessed as clinical scores. RESULTS: None of the patients in the TNS group had grade 3 or 4 SS. In contrast, in the control group, 24% and 40% of patients had grade 3 and 4 SS at the 1- and 3-year follow-ups, respectively. The SS grade was lower in the TNS group than in the control group at the 1- and 3-year follow-ups (p < 0.001). The frequencies of CH in both groups were no significant difference at the 1- and 3-year follow-ups. The JOA scores of the TNS group significantly improved at 1 year after surgery and were comparable to control group. CONCLUSION: The TNS stem reduced SS at 1 and 3 years after THA compared to the proximal-engaging cementless stem, although the shapes of the stems matched. The TNS stem could reduce SS, stem loosening, and periprosthetic fractures. TRIAL REGISTRATION: Current Controlled Trials. ISRCTN21241251. https://www.isrctn.com/search?q=21241251 . The date of registration was October 26, 2021. Retrospectively registered.

Impacts of external rotators and the ischiofemoral ligament on preventing excessive internal hip rotation: a cadaveric study.

BACKGROUND: This study examined the biomechanics of preventing excessive internal hip joint rotation related to the hip flexion angle. METHOD: An intramedullary nail with a circular plate equipped with a protractor was installed in the femur of nine normal hips. The circular plate was pulled by 3.15 Nm of force in the internal rotation direction. The external rotators were individually resected, finally cutting the ischiofemoral ligament. The cutting order of the external rotators differed on each side to individually determine the internal rotation resistance. The external rotators were resected from the piriformis to the obturator externus in the right hips and the reverse order in the left hips. Traction was performed after excising each muscle and ischiofemoral ligament. Measurements were taken at 0°, 30°, and 60° of hip flexion, and the differences from baseline were calculated. RESULTS: For the right hip measurements, the piriformis and ischiofemoral ligament resection significantly differed at 0° of flexion (p = 0.02), each external rotator and the ischiofemoral ligament resections significantly differed at 30° of flexion (p < 0.01), and the ischiofemoral ligament and piriformis and inferior gemellus resections significantly differed at 60° of flexion (p = 0.04 and p = 0.02, respectively). In the left hips, the ischiofemoral ligament and obturator externus, inferior gemellus, and obturator internus resections significantly differed at 0° of flexion (p < 0.01, p < 0.01, and p = 0.01, respectively), as did each external rotator and the ischiofemoral ligament resections at 30° of flexion (p < 0.01). CONCLUSION: The ischiofemoral ligament primarily restricted the internal rotation of the hip joint. The piriformis and obturator internus may restrict internal rotation at 0° and 60° of flexion.

Mid-term results of a new femoral prosthesis using Ti-Nb-Sn alloy with low Young's modulus.

BACKGROUND: This study was performed to investigate the mid-term results of Ti-Nb-Sn (TNS) alloy stem with a low Young's modulus. METHODS: This study was a multicenter prospective cohort study. A total of 40 primary total hip arthroplasties performed between April 2016 and September 2017 was enrolled in this study. With the unique functional gradient properties by heating treatment, the strength of the proximal portion was enhanced, while the distal portion maintained a low Young's modulus. The surgeries were performed through the posterolateral approach using the TNS alloy stems. Radiographs were taken from immediately after surgeries until 3 years, and stress shielding and subsidence of the stems were evaluated. The incidences of the stem breakage were also assessed. Clinical assessments were performed using Japanese Orthopaedic Association (JOA) and Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire (JHEQ) scores. RESULTS: Among the 40 enrolled patients, 36 patients were female and 4 were male. At 3 years after surgery, there were no radiologic signs of loosening, subsidence, or breakage of the stem. Stress shielding was observed in 26 hips (65%). Of 26 hips, 16 hips (40%) were grade 1 and 10 hips (25%) were grade 2. There was no advanced stress shielding. The JOA and JHEQ scores significantly improved compared with the preoperative scores. CONCLUSION: The current study using a new TNS alloy femoral stem showed good clinical outcomes at 3-year follow-up. Radiologically, there was no loosening or subsidence of the stem. The mild stress shielding was observed in 65% of patients. TRIAL REGISTRATION: Current Controlled Trials ISRCTN21241251 . The date of registration was October 26, 2021. Retrospectively registered.

Fatty degeneration and wnt10b expression in the supraspinatus muscle after surgical repair of torn rotator cuff tendon.

PURPOSE: In the torn rotator cuff muscles, decreased expression of wnt10b prior to elevation of peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer-binding protein α (C/EBPα) has previously been reported. The purpose of this study is to elucidate the expression profiles of these adipogenesis-related genes after rotator cuff detachment and reattachment in a rabbit model. METHODS: We investigated gene expression profiles of PPARγ, C/EBPα, and wnt10b in different parts of rabbit supraspinatus (SSP) muscle after tendon detachment (n = 6 for each time point). In addition, we assessed expression of the same genes after SSP reattachment with different intervals from initial detachment (n = 6). Fatty degeneration of the SSP muscle was examined by Oil red-O staining. Gene expression profiles were examined by quantitative real-time polymerase chain reaction. RESULTS: After SSP detachment, Oil red-O-positive oil deposits increased after 3 weeks. In the SSP reattachment model, numerous Oil red-O-positive cells were present at 5-week reattachment, following 2- and 3-week detachment. PPARγ and C/EBPα messenger ribonucleic acid expression exhibited a significant increase at 2 and 3 weeks after SSP detachment and remained increased at 5-week reattachment after 2- and 3-week detachment. A decreased expression of wnt10b was observed from 1 week after SSP detachment. Expression of wnt10b was recovered not in the central area of the SSP muscle but in the periphery after reattachment. Adipogenic change was not observed when SSP tendon was reattached after 1-week detachment. CONCLUSIONS: These results may suggest that once the adipogenic transcription factors, PPARγ and C/EBPα, were elevated, repair surgery after rotator cuff tear could not prevent the emergence of fat in the SSP muscle.

Meniscal tear morphology independently affects pain relief following arthroscopic partial meniscectomy in middle-aged patients.

PURPOSE: To analyze the influence of meniscal tear pattern on clinical outcomes following arthroscopic partial meniscectomy in middle-aged patients with medial meniscal tears. METHODS: A total of 123 patients (130 knees) aged ≥ 50 years who underwent arthroscopic partial meniscectomy for medial meniscal tears were evaluated. Inclusion criteria were none to moderate medial knee osteoarthritis [Kellgren-Lawrence (KL) grade ≤ 3] and a minimum of 2-year follow-up (median 4.6 years; range 2.1-8.0 years). Meniscal tears observed during arthroscopic examination were classified into six types: radial tear of the middle segment, posterior root tear, horizontal tear of the posterior segment, flap tear, minor tear, and complex tear. Postoperative outcomes were classified into effective (group 1) and non-effective (group 2) according to the pain relief administered 1 month postoperatively and at the final follow-up. Demographic variables, KL grade, type of meniscal tear, and postoperative follow-up period were evaluated. RESULTS: Forty knees (38%) were classified into group 1. Of the six types of tears, radial tear of the middle segment [odds ratio (OR) 4.1, 95% confidence interval (CI) 1.1-20.9] and flap tear (OR 12.9, 95% CI 1.8-140.7) were significant predictors of good outcome on multivariate logistic regression analysis. CONCLUSIONS: In middle-aged patients with medial meniscal tears, radial tear of the middle segment was independently associated with less pain following arthroscopic meniscectomy. Arthroscopic partial meniscectomy may be indicated in patients with radial tear if conservative treatment fails. LEVEL OF EVIDENCE: Case-control study, Level III.

Long-term results of a modified Spitzy shelf operation for developmental dysplasia of the hip in adults and adolescents.

The purpose of the current study was to retrospectively evaluate the long-term outcome of our shelf operation for acetabular dysplasia in adults and adolescents. We evaluated the outcome of shelf operation performed in 35 hips of 32 patients with acetabular dysplasia between 1978 and 1996. The mean age at the time of surgery was 30.6 years, and the mean follow-up period was 25.9 years. The pre-operative stage of osteoarthritis was Tönnis grade 0 in 12 hips and grade 1 in 23 hips. Clinical evaluation using the JOA hip score showed more than 85 of 100 points over 25 years. Radiologically, acetabular index was significantly improved after operation. Osteoarthritis deteriorated to grade 3 in 8 of 35 hips (23%) at an average 17.1 years, and accordingly 3 of those 8 hips were converted to THA. The shelf height was significantly higher in those which advanced to grade 3 than in those which did not. There were no significant differences in mean sharp angle, CE angle, AHI, and roundness index. Mean survival was 74% with grade 3 as the endpoint and 72% with THA conversion as the endpoint. Shelf operation provides satisfactory long-term outcome in adults and adolescents with acetabular dysplasia. Higher location of the shelf is a risk factor for advancement of osteoarthritis, whereas sphericity of the femoral head does not affect the long-term results. Further studies are needed to clarify the risk factors about OA progression among the patients with acetabular dysplasia, like as the assessment of three-dimensional morphology of hip joints.

Clinical features and radiological findings of 67 patients with SAPHO syndrome.

OBJECTIVES: The purpose of this study was to facilitate the understanding of the SAPHO (Synovitis, Acne, Pustulosis, Hyperostosis, and Osteitis) syndrome by analyzing the clinical and radiological features of 67 Japanese patients with SAPHO syndrome. METHODS: Sixty-seven Japanese patients (female/male: 44/23, mean age at onset: 48.5 years) were diagnosed with SAPHO syndrome from 2002 to 2013 at our hospital. Medical records and radiological imaging of these patients were retrospectively reviewed. RESULTS: Among the 67 patients, 41 had dermatological manifestations, such as palmoplantar pustulosis, acne, and psoriasis. Initial symptom was local pain in all patients, and the most common initial site of the symptom was the anterior chest. Bacterial and fungal cultures from 20 bone biopsies were all negative. Histopathological diagnosis of the specimens was non-specific inflammation in all cases. Bone lesions were observed in 65 patients (97.0%). On the other hand, articular lesions including enthesitis were found in 31 patients (46.2%). CONCLUSION: SAPHO syndrome had different clinical and radiological aspects. The clinical features were not remarkable, except the dermatological manifestations and the involvement of the anterior chest. Bone lesions including hyperostosis and osteitis were found radiographically in the majority of patients with SAPHO syndrome. These are the characteristics of the SAPHO syndrome, with the exclusion of other bone diseases.

Bone mineral density of postmenopausal women with rheumatoid arthritis depends on disease duration regardless of treatment.

The aim of this study was to determine the associations of disease activity and disease duration with the bone mineral density (BMD) in rheumatoid arthritis (RA) patients. We also evaluated the associations of biological drugs with bone loss. A total of 138 postmenopausal RA patients were retrospectively assessed to identify the associations of disease activity, disease duration, and biological drug use with BMD. We assessed the associations of disease duration, a C-reactive protein based disease activity score in 28 joints (DAS28), simplified disease activity index, clinical disease activity index, health assessment questionnaire scores, and the use of biological drugs with the lumbar spine, total hip, and femoral neck BMDs using univariate and multivariate linear regression analyses in bisphosphonate treatment and non-bisphosphonate treatment groups at 1 year of follow-up. The multivariate linear regression analyses showed that disease duration was significantly related to the BMD of the femoral neck and total hip regardless of bisphosphonate treatment. The use of biological drugs was not significantly associated with BMD. Hip BMD in postmenopausal women with RA depends on the disease duration regardless of bisphosphonate use. Biological drugs for RA treatment were not negatively associated with general bone loss.

Patient trends in orthopedic traumas and related disorders after tsunami caused by the Great East Japan Earthquake: An experience in the primary referral medical center.

BACKGROUND: In the Great East Japan Earthquake, the Japanese Red Cross Ishinomaki Hospital played an important role as a principal referral center within the Ishinomaki region, one of the most severely affected areas in eastern Japan. The present study describes the patient population, clinical characteristics, and time courses of the medical problems observed at this hospital. METHODS: A retrospective survey of medical logs and records was conducted on the first 2 weeks after the earthquake to characterize orthopedic traumas and related disorders treated during this catastrophe. Patient number, severity of injuries, number of patients secondarily transported to the referral medical centers in the inland area, and the number of surgeries performed during the study period were investigated. RESULTS: Totally, 7686 patients visited the hospital. Of which, 1807 patients suffered from exogenous diseases, such as trauma, burns, crush syndrome, deep venous thrombosis, and infectious diseases. Patients who suffered from hypothermia were the most frequently seen within the first 2 weeks after the earthquake. Interestingly, most patients' conditions were not severe and required only simple treatments. Four patients (0.2% of patients with exogenous diseases) were secondarily transported to the referral medical centers in the inland area and only four patients were surgically treated because of a lack of available implants, surgical devices, and electric power supply. DISCUSSION AND CONCLUSIONS: The Great East Japan Earthquake and subsequent tsunami, which occurred during an early spring afternoon, resulted in a unique orthopedic patient population, which included few severely injured patients compared with numerous deaths. We believe that each coastal region hospital should develop its own emergency medical care system to address future tsunami events while considering their surrounding environment. The information described in the present study should be important for preparation toward future events involving massive earthquakes followed by tsunami disasters.

The role of an octacalcium phosphate in the re-formation of infraspinatus tendon insertion.

BACKGROUND: To improve the success rate of rotator cuff repair, we investigated whether octacalcium phosphate (OCP) with gelatin (Gel) vehicle had a positive effect on tendon-to-bone healing. METHODS: We assessed the histologic characteristics of the tendon-to-bone healing using the rabbit rotator cuff repair model. We divided the shoulders into 3 groups: control (without OCP/Gel composite), OCP/Gel composite (OCP+group), and Gel alone without OCP (Gel group) to evaluate the effectiveness of gelatin. RESULTS: Both the number of newly formed tendon fibers and the Sharpey fibers at the repair site increased in the OCP+group compared with those in the other 2 groups on hematoxylin-eosin staining (P < .05). On immunohistochemical evaluation, both the bone and the fibers in the OCP+group demonstrated that type I collagen was picked up, whereas the newly formed tendon fibers and Sharpey fibers revealed type III collagen. CONCLUSION: Treatment with OCP made collagen fibers and the Sharpey fibers, constituted by type I and type III collagens, increase at the tendon-to-bone insertion. It might be beneficial for the healing of rotator cuff tendon to bone.

Efficacy of methotrexate and tumor necrosis factor inhibitors in Japanese patients with active psoriatic arthritis.

OBJECTIVE: The aim of this study was to assess the efficacy of oral methotrexate and tumor necrosis factor inhibitors in Japanese patients with active psoriatic arthritis. METHODS: We retrospectively investigated 51 patients who fulfilled the ClASsification criteria for Psoriatic ARthritis (CASPAR) criteria for the efficacy of tumor necrosis factor inhibitors and methotrexate. We assessed the visual analog scale score, psoriasis area and severity index score, C-reactive protein-based disease activity score in 28 joints (DAS28), swollen joint count (0-66), tender joint count (0-68), health assessment questionnaire score, C-reactive protein level, erythrocyte sedimentation rate, and matrix metalloproteinase 3, at both baseline and week 24. RESULTS: Of the 51 patients, 34 were male and 17 were female, with a mean age of 50.3 ± 13.2 years. The duration of psoriasis to onset of arthritis was 10.2 ± 9.1 years. At week 24, in the group treated with the tumor necrosis factor inhibitor plus methotrexate, the tender joint count declined from 6.05 ± 5.84 to 0.43 ± 1.03, the swollen joint count declined from 6.42 ± 4.36 to 0.00 ± 0.00, and the DAS28 declined from 4.35 ± 0.82 to 2.04 ± 0.68. In the group treated with methotrexate alone, the tender joint count declined from 3.70 ± 1.76 to 0.60 ± 0.86, the swollen joint count declined from 5.26 ± 4.00 to 0.27 ± 0.70, and the DAS28 declined from 3.91 ± 0.82 to 1.94 ± 0.53. There were no significant differences in the mean reduction in clinical measurements between the two groups. CONCLUSION: Our study demonstrated that methotrexate and tumor necrosis factor inhibitors are effective for the treatment of active psoriatic arthritis in Japanese patients.