Bone Density Distribution Pattern in the Lateral Wall of the Femoral Intercondylar Notch: Implications for the Direct Insertion of the Femoral ACL Attachment.

Background: The ideal position of the femoral bone tunnel in the anterior cruciate ligament (ACL) is controversial. The functional importance of the ACL fiber varies depending on where it is attached to the femur. Functionally important fibers can cause high mechanical stress on the bone, and the Wolff law predicts that bone mineral density will increase at high mechanical stress sites. Purpose/Hypothesis: The purpose of this study was to use computed tomography imaging to determine the distribution pattern of bone density in the lateral intercondylar wall. It was hypothesized that the high-density area (HDA) of the lateral intercondylar wall would reflect the functional insertion of the ACL as reported in previous anatomic studies. Study Design: Descriptive epidemiology study. Methods: Data from 39 knees without ACL injuries were retrospectively collected. The HDA of the lateral intercondylar wall was defined as the region containing the top 10% of the radiodensity values. The shape of the HDA was approximated as an ellipse, and the quadrant method was used to determine the center of the ellipse. The association between the ratio of the minor axis to the major axis of the ellipse and background characteristics was investigated. Results: According to the quadrant method, the center of the HDA ellipse was 33.6% in the deep-shallow direction and 23.4% in the high-low direction. The center of the ellipse was comparable to the anatomic center of the ACL footprint, as previously reported. The ratio of the minor axis to the major axis of the ellipse was 0.58 (95% CI, 0.54-0.62). There was a significant negative correlation between the ratio of the minor axis to the major axis of the HDA ellipse and the posterior tibial slope (r = -0.38, P = .02). Conclusion: The center of the HDA ellipse was found to be similar to the anatomic center of the ACL footprint. Considering the mechanical stress responses in bone, the HDA of the lateral intercondylar wall has the potential to represent the ACL insertion, especially functional insertion.

Amputation surgery associated with shortened survival in patients with localized soft tissue sarcoma.

BACKGROUND: The objectives of this study were to clarify whether localized extremity soft tissue sarcoma (STS) patients who underwent amputation surgery experienced worsened survival and to identify those patients for whom amputation surgery worsened survival. METHODS: Using the Surveillance, Epidemiology, and End Results database, we identified 8897 patients with localized extremity STS between 1983 and 2016. Of these 6431 patients, 733 patients underwent amputation surgery (Amputation group), and 5698 underwent limb-sparing surgery (Limb-sparing group). RESULTS: After adjusting for patient background by propensity score matching, a total of 1346 patients were included. Patients in the Amputation group showed worsened survival (cancer-specific survival (CSS): hazard ratio (HR) = 1.42, 95% confidence interval (CI) 1.15-1.75, overall survival (OS): HR = 1.41, 95%CI 1.20-1.65). In subclass analysis, patients with high-grade STS, spindle cell sarcoma and liposarcoma in the Amputation group showed shortened survival (high-grade-CSS: HR = 1.44, 95%CI 1.16-1.77, OS: HR = 1.38, 95%CI 1.18-1.62; spindle cell sarcoma-CSS: HR = 4.75, 95%CI 1.56-14.4, OS: HR = 2.32, 95%CI 1.45-3.70; liposarcoma-CSS: HR = 2.91, 95%CI 1.54-5.50, OS: HR = 2.32, 95%CI 1.45-3.70). CONCLUSIONS: Survival was shortened in localized extremity STS patients who received amputation surgery.

Symptomatic bilateral complete discoid medial menisci of the knee in a child: A case report.

Bilateral complete discoid medial menisci are extremely rare congenital anatomic variants of the knee. Currently, arthroscopic partial meniscectomy with or without peripheral suture repair is performed for symptomatic discoid meniscus. However, most of the outcomes are short-term. In this article, we present a pediatric case of symptomatic bilateral complete discoid medial menisci and highlight the effectiveness of arthroscopic partial meniscectomy with or without peripheral suture on symptomatic complete discoid medial menisci based on 60-month excellent clinical and functional results.

Occurrence Rate of Cyclops Lesion After Anatomic Double-Bundle ACL Reconstruction: Comparison Between Remnant Tissue Preservation and Resection Methods.

Background: The occurrence rate of cyclops lesion after anatomic double-bundle anterior cruciate ligament (ACL) reconstruction with remnant tissue preservation remains unclear. Hypothesis: The study hypotheses were as follows: (1) the occurrence rate of cyclops lesion will be comparable between the remnant-preserving and remnant-resecting ACL reconstruction methods, and (2) there will be no significant differences in clinical outcomes between the remnant-preserving and remnant-resecting procedures. Methods: This retrospective comparative study involved 177 patients who underwent unilateral anatomic double-bundle ACL reconstruction using hamstring tendon autografts from 2014 to 2018 at our hospital. According to the Crain classification of ACL remnant tissue, 98 patients with remnant types I, II, or III underwent the remnant-preserving procedure (group A), and the remaining 79 patients with remnant type IV underwent the remnant-resecting procedure (group B). All patients underwent second-look arthroscopy. Patients were evaluated according to arthroscopic and clinical results at postoperative 15.2 ± 8.4 months (mean ± SD). Statistical comparisons between groups were made using the paired Student t test, chi-square test, and Fisher exact test. Study Design: Cohort study; Level of evidence, 3. Results: At second-look arthroscopy, the incidence of cyclops lesions was significantly higher in group B than in group A (29.1% vs 13.3%; P = .0139). Cyclops lesions were divided into 4 locations: femoral side (type 1), midsubstance (type 2), tibial side (type 3), and anterior (type 4) of the ACL graft. The ratio of the tibial-side cyclops lesion (type 3) was significantly higher in group B than in group A (P = .0354). There were no significant differences in the clinical evaluation scores between the procedures. Side-to-side anterior laxity was significantly less in group A than in group B (0.7 vs 1.6 mm; P = .0035). Concerning postoperative laceration and synovium coverage of the grafts, group A was significantly better than group B (P < .0001). Conclusion: In this cohort of patients undergoing double-bundle ACL reconstruction, resection of the ACL remnant was associated with a significantly higher rate of cyclops lesion formation when compared with preservation of the remnant.

Comparison of clinical features between patients with bone and soft tissue fibrosarcomas.

BACKGROUND AND OBJECTIVES: Fibrosarcomas predominantly arise in soft tissues, but can also develop in bone. Because of their rarity, whether bone development has an impact on clinical features has not been addressed. METHODS: We included fibrosarcoma patients diagnosed between 1983 and 2016 in the Surveillance, Epidemiology, and End Results database. Differences in clinical features between fibrosarcoma of bone (FS-B) and fibrosarcoma of soft tissue (FS-ST) were investigated. RESULTS: After excluding patients without information regarding cause of death, site of origin, distant tumor or survival, 1443 patients were included. Of those, 98 patients had FS-B. Patients with FS-B were younger, more frequently male, with fibrosarcomas that more often developed in an extremity and were histologically high-grade. In contrast, no difference in potential to metastasize was observed. Survival was almost equal between FS-B and FS-ST (FS-B/FS-ST: cancer-specific survival, hazard ratio [HR]: 1.2, 95% confidence interval [CI]: 0.8-1.7; overall survival, HR: 1.3, 95% CI: 0.9-1.7). CONCLUSIONS: Our results clearly indicated that patient backgrounds differed, such as younger age and greater tendencies to affect males, develop in an extremity and show high-grade tumor in patients with FS-B. In contrast, no differences were observed in distant metastatic potential or survival.

Liver metastasis in soft tissue sarcoma at initial presentation.

BACKGROUND AND OBJECTIVES: Noncontrast computed tomography of the chest is the standard imaging modality for cancer staging in patients with soft tissue sarcoma (STS), but appropriate candidates for liver screening have not been clarified. METHODS: We reviewed all patients with STS diagnosed between 2010 and 2018 in the Surveillance, Epidemiology, and End Results database. Incidence of liver metastasis at initial presentation and high incidence of liver metastasis by histological subtype were investigated. In addition, risk factors for liver metastasis were investigated by multiple logistic regression analysis. RESULTS: After excluding patients without information about liver metastasis, cause of death or primary liver tumor, 47 260 patients were included in this study. Of those, 1471 patients (3.2%) showed liver metastasis at initial presentation. The histological subtype showing the highest incidence of liver metastasis was desmoplastic small round cell tumor (30.3%), followed by malignant hemangioendothelioma (11.5%) and angiomyoliposarcoma (10.5%). Deep-rooted tumor, location in the body wall, retroperitoneum, or thorax/peritoneum, high histological grade, and higher T stage were associated with higher incidences of liver metastasis at initial presentation. CONCLUSION: Risk factors for liver metastasis were deep location, trunk development, larger tumor size, high histological grade, and specific histological subtypes.

Does Primary Tumor Resection in Patients with Metastatic Primary Mobile Vertebral Column Sarcoma Improve Survival?

BACKGROUND: Primary mobile vertebral column sarcoma is an exceedingly rare malignancy. Although primary tumor resection has been reported to prolong survival in patients with metastatic bone sarcoma, whether primary tumor resection in patients with advanced primary mobile vertebral column sarcoma is associated with survival remains unclear owing to the rarity of this pathological entity. METHODS: Using the Surveillance, Epidemiology, and End Results database, 182 patients with metastatic primary mobile vertebral column sarcoma were identified between 1983 and 2015. Of the 182 patients enrolled, 101 patients (55%) underwent primary tumor resection (Surgery group) and 81 patients (45%) did not undergo resection (No Surgery group). To account for imbalances in the basic characteristics of patients between groups, propensity score matching was performed. Survival analysis was performed by weighted Cox proportional hazards modeling to calculate hazard ratios. RESULTS: After adjusting for patient background characteristics, 138 patients were included for the analysis (Surgery group: 69 patients; No Surgery group: 69 patients). The Surgery group did not show improved cancer-specific survival (hazard ratio = 0.73, 95% CI 0.49-1.10). Similarly, the Surgery group did not show improved overall survival compared with the No Surgery group (hazard ratio = 0.80, 95% CI 0.55-1.16). CONCLUSIONS: To our knowledge, this is the first study to indicate that surgical resection for advanced primary mobile vertebral column sarcoma does not have a positive impact on survival.

The effect of local injection of tranexamic acid into peri-articular tissue versus drain clamping in total knee arthroplasty: a randomized controlled trial.

BACKGROUND: Tranexamic acid (TXA) is used as a synthetic anti-fibrinolytic agent for total knee arthroplasty (TKA) to reduce postoperative bleeding. Though the effects on bleeding reduction of several methods of administering TXA have been demonstrated, the optimal method remains controversial. Recently, the hemostatic effect of periarticular local injection of TXA during TKA was reported. Although this method can be expected to suppress postoperative bleeding without placing a drain, its hemostatic effect has not yet been assessed in comparison with local injection and other methods of administering TXA. The aim of this randomized, prospective study was to assess the efficacy of local injection of TXA during TKA. METHODS: To confirm the effect of the local injection of TXA, drain clamping was set as the control. The subjects included a prospective series of 109 patients randomly divided into 2 groups: the local injection (group L) and the drain clamping (group D). The main outcome measure was postoperative bleeding. Secondary outcomes included pain, physical measurements, and laboratory findings. RESULTS: The calculated total blood loss (CTBL) in groups L and D was nearly equal and did not show the non-inferiority of group L to group D (883 ± 248 vs. 841 ± 257 ml, P = .564). Drained blood loss was significantly higher in group L than in group D (395 ± 130 vs 276 ± 78.8 ml, P < .0001). There was no significant difference in hidden blood loss between the groups (488 ± 269 vs 565 ± 261 ml, P = .131). The other laboratory findings and physical measurements were identical between the groups. CONCLUSIONS: Although CTBL in group L did not show non-inferiority to group D, the local injection of TXA was considered to be superior for suppressing bleeding considering the risk of the adverse effects of using a drain. TRIAL REGISTRATION: This was a randomized, prospective study registered with UMIN Clinical Trials Registry (Registration number: UMIN000036146, date of disclosure: 10/3/2019).

Double-bundle anterior cruciate ligament reconstruction using autologous hamstring tendon hybrid grafts in a patient with hypermobile Ehlers-Danlos Syndrome: A case report.

BACKGROUND: Ehlers-Danlos syndrome (EDS) is a connective tissue disorder characterized by skin hyperextensibility, joint hypermobility, and tissue friability. Hypermobile type Ehlers-Danlos syndrome (hEDS) is considered one of the EDS subtypes characterized by generalized joint hypermobility. Although there have been a few case reports which described surgical considerations for anterior cruciate ligament (ACL) reconstructions in patients with other types of EDS, no reports have described those in patients with hEDS. CASE PRESENTATION: We report a case of ACL injury in an 18-year-old male patient with hEDS. The patient was successfully treated with an anatomic double-bundle ACL reconstruction using autologous hamstring tendon hybrid grafts which consist of hamstring tendons connected in a series with commercially available polyester tape. The autogenous tendon portion of the anteromedial and posterolateral bundles were composed of 4 and 2 strands of hamstring tendons, respectively. After 2 weeks of knee joint immobilization, continuous passive motion exercise of the knee joint and partial weight-bearing was allowed. A hinged knee brace was used for a period of 5 months postoperatively. Second-look arthroscopy at 30 months showed that the ACL graft had no laceration and an excellent coverage of the synovium. At 36 months after surgery, the side-to-side differences in the anterior laxity was remarkably improved. The operated knee showed negative Lachman test and had a full range of motion. CONCLUSIONS: To the best of our knowledge, this represents the first report of anatomic double-bundle ACL reconstruction in patients with hEDS and demonstrates excellent clinical and functional outcomes.

Primary Malignant Osseous Neoplasms in the Hand.

BACKGROUND: Primary malignant osseous neoplasms of the hand are rare malignancies. Comprehensive demographic and survival data regarding primary malignant osseous neoplasms of the hand are lacking in the literature. PATIENTS AND METHODS: Using the Surveillance, Epidemiology, and End Results (SEER) database, we identified all patients with primary malignant osseous neoplasms of the hand diagnosed between 1983 and 2015. Demographic data were searched for primary osseous neoplasms in the hand and higher incidence of histological subtype. RESULTS: A total of 197 patients were analyzed: 103 patients were diagnosed with histologically low-grade tumor, and 31 were diagnosed with high-grade tumor. Five-year cancer-specific and overall survival rates for the entire cohort were 91.4% and 81.9%, respectively. Histological high tumor grade and regional stage from SEER historic stage data were associated with unfavorable cancer-specific survival. CONCLUSION: Special caution is required if patients have histologically high-grade tumor or tumor extending beyond the periosteum into surrounding joints, as these features worsen cancer-specific mortality.

Discrepancy in the Distribution Patterns of Subchondral Bone Density Across the Ankle Joint After Medial Opening-Wedge and Lateral Closing-Wedge High Tibial Osteotomy.

BACKGROUND: High tibial osteotomy (HTO) changes the alignment and dynamics of the ankle joint; however, differences in the stress distribution of the ankle joint after opening-wedge HTO (OWHTO) and closing-wedge HTO (CWHTO) are not understood. It is believed that subchondral bone density of the articular surface reflects the pattern of cumulative stress distribution across the joint surface. PURPOSE: To clarify the effects of OWHTO and CWHTO on the distribution patterns of subchondral bone density across the ankle joint using computed tomography (CT)-osteoabsorptiometry. STUDY DESIGN: Cohort study; Level of evidence, 4. METHODS: Radiographic and CT data of 18 cases who underwent OWHTO (OW group), 12 cases who underwent CWHTO (CW group), and 11 cases with unilateral anterior cruciate ligament injury serving as controls were retrospectively reviewed. The subchondral bone density of the distal tibia was assessed in the 3 groups using CT-osteoabsorptiometry. The distal tibial surface of the ankle joint was divided into 4 parts in the coronal direction, and the percentage of the high-density area (%HDA) to each subregion was compared before and after HTO. RESULTS: Preoperatively, comparing %HDA among the 3 groups, there were no significant differences in any regions. In the OW group, postoperative %HDA in the most medial region was significantly increased compared with preoperative %HDA (49.3% to 53.0%; P = .011), and postoperative %HDA in the most lateral region was significantly decreased (21.4% to 17.2%; P = .003). On the other hand, in the CW group, postoperative %HDA in the most medial region was significantly decreased (55.7% to 35.7%; P = .001), and %HDA in the second lateral region was significantly increased (23.6% to 29.2%; P = .002). CONCLUSION: The ankle distribution pattern of subchondral bone density shifted significantly medially after OWHTO without fibular osteotomy, whereas the distribution pattern shifted laterally after CWHTO with fibular osteotomy. When the OWHTO is performed for patients with medial ankle osteoarthritis, surgeons should pay attention to potential postoperative progression of ankle osteoarthritis due to medial shift of the stress distribution in the ankle joint.

Quantification of Cartilage Surface Degeneration by Curvature Analysis Using 3D Scanning in a Rabbit Model.

OBJECTIVE: Accurate analysis to quantify cartilage morphology is critical for evaluating degenerative conditions in osteoarthritis (OA). Three-dimensional (3D) optical scanning provides 3D data for the entire cartilage surface; however, there is no consensus on how to quantify it. Our purpose was to validate a 3D method for evaluating spatiotemporal alterations in degenerative cartilages in a rabbit OA model by analyzing their curvatures at various stages of progression. DESIGN: Twelve rabbits underwent anterior cruciate ligament transection (ACLT) unilaterally and were divided into 4 groups: 4 weeks control, 4 weeks OA, 8 weeks control, and 8 weeks OA. 3D scanning, India ink staining, and histological assessments were performed in all groups. In 3D curvature visualization, the surfaces of the condyles were divided into 8 areas. The standard deviations (SD) of mean curvatures from all vertices of condylar surfaces and subareas were calculated. RESULTS: Regarding the site of OA change, curvature analysis was consistent with India ink scoring. The SD of mean curvature correlated strongly with the India ink Osteoarthritis Research Society International (OARSI) score. In curvature histograms, the curvature distribution in OA was more scattered than in control. Of the 8 areas, significant OA progression in the posterolateral part of the lateral condyle (L-PL) was observed at 4 weeks. The histology result was consistent with the 3D evaluation in terms of representative section. CONCLUSIONS: This study demonstrated that 3D scanning with curvature analysis can quantify the severity of cartilage degeneration objectively. Furthermore, the L-PL was found to be the initial area where OA degeneration occurred in the rabbit ACLT model.

Brain Metastasis in Soft Tissue Sarcoma at Initial Presentation.

BACKGROUND/AIM: Brain metastasis is a rare condition among patients with soft tissue sarcoma (STS), and its precise incidence remains unclear. The aim of this study was to investigate which patients should be screened for brain metastasis. PATIENTS AND METHODS: We identified all patients with STS diagnosed between 2010 and 2015 in the SEER database. Incidence of brain metastasis at initial presentation and higher incidence of brain metastasis by histological subtype were investigated. In addition, risk factors for brain metastasis were examined. RESULTS: A total of 26,676 patients were included for analysis, of whom 162 patients (0.6%) had brain metastasis. Alveolar soft part sarcoma (6.3%), malignant hemangioendothelioma (3.1%) and malignant schwannoma (2.6%) showed higher incidence of brain metastasis. Deep-rooted tumor, trunk tumor, and histological high-grade tumor tended to show higher incidence of brain metastasis. CONCLUSION: Risk factors for brain metastasis were deep location, trunk development and histologically high-grade tumor, or specific histological subtypes.

Delayed Onset of Infectious Foreign Body Granuloma for Nonabsorbable Sutures After Open Achilles Tendon Repair: A Case Report.

Foreign body granulomas from sutures are more common among non-absorbable sutures compared to absorbable sutures and have been reported as a postoperative complication in a variety of medical fields. However, only a few cases of delayed foreign body reaction have been reported and addressed with orthopedics. We present a patient with systemic lupus erythematosus who developed an infectious suture granuloma that extended to the entire Achilles tendon and was induced by nonabsorbable sutures that were used for open Achilles tendon repair 20 years before. This granuloma was resistant to antibiotic treatment and drainage and required surgical intervention. The tumor was marginally resected, and the continuity of the Achilles tendon was preserved. Histopathological examination detected many suture materials surrounded by xanthochromic necrotic lesions and the lesion was diagnosed as a foreign body granuloma. At 1 year after the operation, the patient did not exhibit exacerbation of infection or recurrence of the tumor, and she became able to walk by herself. To the best of our knowledge, this represents the first report of an infectious delayed foreign body granuloma in autoimmune disorder patient after open Achilles tendon repair. Surgical intervention should be considered, as treatment with conservative therapy such as antibiotics may be difficult.

Ultrapurified Alginate Gel Containing Bone Marrow Aspirate Concentrate Enhances Cartilage and Bone Regeneration on Osteochondral Defects in a Rabbit Model.

BACKGROUND: Ultrapurified alginate (UPAL) gel implantation has been demonstrated as effective in cartilage repair for osteochondral defects; however, cell transplantation within UPAL gels would be required to treat larger defects. HYPOTHESIS: The combination of UPAL gel and bone marrow aspirate concentrate (BMAC) would enhance cartilage repair and subchondral bone repair for large osteochondral defects. STUDY DESIGN: Controlled laboratory study. METHODS: A total of 104 osteochondral defects (1 defect per knee) of 52 rabbits were randomly divided into 4 groups (26 defects per group): defects without any treatment (Defect group), defects treated using UPAL gel alone (UPAL group), defects treated using UPAL gel containing allogenic bone marrow mesenchymal stromal cells (UPAL-MSC group), and defects treated using UPAL gel containing BMAC (UPAL-BMAC group). At 4 and 16 weeks postoperatively, macroscopic and histologic evaluations and measurements of repaired subchondral bone volumes of reparative tissues were performed. Collagen orientation and mechanical properties of the reparative tissue were assessed at 16 weeks. RESULTS: The defects in the UPAL-BMAC group were repaired with hyaline-like cartilage with well-organized collagen structures. The histologic scores at 4 weeks were significantly higher in the UPAL-BMAC group (16.9 ± 2.0) than in the Defect group (4.7 ± 1.9; P < .05), the UPAL group (10.0 ± 3.3; P < .05), and the UPAL-MSC group (12.2 ± 2.9; P < .05). At 16 weeks, the score in the UPAL-BMAC group (24.4 ± 1.7) was significantly higher than those in the Defect group (9.0 ± 3.7; P < .05), the UPAL group (14.2 ± 3.9; P < .05), and the UPAL-MSC group (16.3 ± 3.6; P < .05). At 4 and 16 weeks, the macroscopic evaluations were significantly superior in the UPAL-BMAC group compared with the other groups, and the values of repaired subchondral bone volumes in the UPAL-BMAC group were significantly higher than those in the Defect and UPAL groups. The mechanical properties of the reparative tissues were significantly better in the UPAL-BMAC group than in the other groups. CONCLUSION: The implantation of UPAL gel containing BMAC-enhanced hyaline-like cartilage repair and subchondral bone repair of osteochondral defects in a rabbit knee model. CLINICAL RELEVANCE: These data support the potential clinical application of 1-step treatment for large osteochondral defects using biomaterial implantation with cell transplantation.

Hallux Valgus With Second Brachymetatarsia Discovered Accidentally: A Case Report.

Hallux valgus deformity is one of the most common foot and ankle diseases, while brachymetatarsia is a rare foot anomaly with pathological shortening of a metatarsal bone. We present a case of hallux valgus deformity possibly due to second brachymetatarsia. As the hallux valgus was associated with dorsal dislocation of the second toe that made it difficult to evaluate the length of the second toe, the patient was unaware of the second metatarsal shortening until the lengths of the toes compared by manual reposition of the second MTP joint. In this case, proximal osteotomy of the first metatarsal on the hallux valgus and single-stage bone lengthening of the second metatarsal with iliac bone grafting on the second brachymetatarsia were performed. One year after the operation, the callosity of the third toe resolved and the clinical scores were improved. In the case of a hallux valgus deformity with second dorsal dislocation of the toes, surgeons should consider that there are rare cases with second metatarsal shortening. When hallux valgus associated with second brachymetatarsia is diagnosed, second metatarsal lengthening should be considered in addition to hallux valgus surgery.

Local Administration of Low-Dose Nerve Growth Factor Antibody Reduced Pain in a Rat Osteoarthritis Model.

Systemic injection of a nerve growth factor (NGF) antibody has been proven to have a significant relevance in relieving osteoarthritis (OA) pain, while its adverse effects remain a safety concern for patients. A local low-dose injection is thought to minimize adverse effects. In this study, OA was induced in an 8-week-old male Sprague-Dawley (SD) rat joint by monoiodoacetate (MIA) injection for 2 weeks, and the effect of weekly injections of low-dose (1, 10, and 100 µg) NGF antibody or saline (control) was evaluated. Behavioral tests were performed, and at the end of week 6, all rats were sacrificed and their knee joints were collected for macroscopic and histological evaluations. Results showed that 100 µg NGF antibody injection relieved pain in OA rats, as evidenced from improved weight-bearing performance but not allodynia. In contrast, no significant differences were observed in macroscopic and histological scores between rats from different groups, demonstrating that intra-articular treatment does not worsen OA progression. These results suggest that local administration yielded a low effective NGF antibody dose that may serve as an alternative approach to systemic injection for the treatment of patients with OA.

Which Contributes to Meniscal Repair, the Synovium or the Meniscus? An In Vivo Rabbit Model Study With the Freeze-Thaw Method.

BACKGROUND: During meniscal tissue repair, the origin of the reparative cells of damaged meniscal tissue remains unclear. HYPOTHESIS: Comparison of the influence between meniscal and synovial tissues on meniscal repair by the in vivo freeze-thaw method would clarify the origin of meniscal reparative cells. STUDY DESIGN: Controlled laboratory study. METHODS: A total of 48 mature Japanese white rabbits were divided into 4 groups according to the tissue (meniscal or synovial) that received freeze-thaw treatment. The meniscus of each group had a 2 mm-diameter cylindrical defect filled with alginate gel. Macroscopic and histologic evaluations of the reparative tissues were performed at 1, 3, and 6 weeks postoperatively. Additional postoperative measurements included cell density, which was the number of meniscal cells in the cut area per cut area (mm2) of meniscus; cell density ratio, which was the cell density of the sample from each group per the average cell density of the intact meniscus; and cell death rate, which was the number of cells stained by propidium iodide per the number of cells stained by Hoechst 33342 of the meniscal tissue adjacent to the defect. RESULTS: The macroscopic and histologic evaluations of the non-synovium freeze-thaw groups were significantly superior to those of the synovium freeze-thaw groups at 3 and 6 weeks postoperatively. Additionally, the meniscal cell density ratio and cell death rate in the freeze-thaw groups were significantly lower than those in the non-meniscal freeze-thaw groups at 3 and 6 weeks postoperatively. CONCLUSION: The freeze-thawed meniscus recovered few cells in its tissue even after 6 weeks. However, the defect was filled with fibrochondrocytes and proteoglycan when the synovium was intact. On the basis of these results, it is concluded that synovial cells are the primary contributors to meniscal injury repair. CLINICAL RELEVANCE: In meniscal tissue engineering, there is no consensus on the best cell source for meniscal repair. Based on this study, increasing the synovial activity and contribution should be the main objective of meniscal tissue engineering. This study can establish the foundation for future meniscal tissue engineering.

Ten years change in post-fracture care for hip fracture patients.

INTRODUCTION: This multicenter, retrospective study aimed to clarify the changes in postoperative care provided by orthopaedic surgeons after hip fractures and clarify the incidence of secondary fractures requiring surgery. MATERIALS AND METHODS: Subjects were patients with hip fracture treated surgically in seven hospitals during the 10-year period from January 2008 to December 2017. Data on patient demographics, comorbidities, preoperative and postoperative osteoporosis treatments, and secondary fractures were collected from the medical records. RESULTS: In total, 4764 new hip fractures in 982 men and 3782 women (mean age: 81.3 ± 10.0 years) were identified. Approximately 10% of patients had a history of osteoporosis drug treatment and 35% of patients received postoperative drug treatment. The proportion of patients receiving postoperative drug therapy increased by approximately 10% between 2009 and 2010, 10% between 2010 and 2011, and 10% between 2011 and 2013. Although the rate of secondary fractures during the entire period and within 3 years decreased from 2011, the rate of secondary fracture within 1 year remained at around 2% every year. CONCLUSIONS: The approval of new osteoporosis drugs and the establishment of osteoporosis liaison services have had a positive effect on the use of postoperative drug therapy in the orthopedic field. Our finding that the rate of secondary fracture within 1 year of the initial fracture remained around 2% every year, despite improvements in postoperative drug therapy, suggests that both rehabilitation for preventing falls and early postoperative drug therapy are essential to prevent secondary fractures.

CCL21/CCR7 axis regulating juvenile cartilage repair can enhance cartilage healing in adults.

Juvenile tissue healing is capable of extensive scarless healing that is distinct from the scar-forming process of the adult healing response. Although many growth factors can be found in the juvenile healing process, the molecular mechanisms of juvenile tissue healing are poorly understood. Here we show that juvenile mice deficient in the chemokine receptor CCR7 exhibit diminished large-scale healing potential, whereas CCR7-depleted adult mice undergo normal scar-forming healing similar to wild type mice. In addition, the CCR7 ligand CCL21 was transiently expressed around damaged cartilage in juvenile mice, whereas it is rarely expressed in adults. Notably, exogenous CCL21 administration to adults decreased scar-forming healing and enhanced hyaline-cartilage repair in rabbit osteochondral defects. Our data indicate that the CCL21/CCR7 axis may play a role in the molecular control mechanism of juvenile cartilage repair, raising the possibility that agents modulating the production of CCL21 in vivo can improve the quality of cartilage repair in adults. Such a strategy may prevent post-traumatic arthritis by mimicking the self-repair in juvenile individuals.