Simple Linear Calculating Method of Glenoid Bone Defects Using 3-Dimensional Computed Tomography Based on an East Asian Population in China.

BACKGROUND: The evaluation of glenoid bone defects in the preoperative stage for patients with anterior shoulder instability is critical for surgical decision making. A novel method that predicts the intact glenoid width based purely on the measurement of the glenoid height has been advocated. Despite the convenience, all studies to date have focused on the Western population, and there is no similar research based on an East Asian population. PURPOSE: To determine the relationship between glenoid height and width in an East Asian population. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: Spiral computed tomography (CT) scans of both sides of the shoulder joints were obtained from 205 patients of Han nationality (China) who had no history of shoulder trauma or pain. The maximal height and width of each glenoid were measured on the en face view by 2 radiologists who were blinded to each other's results. Pearson correlation coefficients and multivariable linear regression were calculated from all data measured to evaluate the relationship between maximal glenoid height and width between the sexes. RESULTS: A total of 205 patients (410 shoulder CT scans) were analyzed. The mean glenoid height was 34.45 ± 2.82 mm, and the mean glenoid width was 23.35 ± 2.40 mm. There was a statistical difference between male and female patients with regard to glenoid height (36.61 vs 32.39 mm, respectively; t = 9.76; P < .001) and width (25.26 vs 21.54 mm, respectively; t = 20.73; P < .001). Analysis of the measured glenoid height and width demonstrated a strong linear correlation of 0.82 (R 2 = 0.68; P < .001) for the entire cohort and similarly strong linear correlations when each sex was analyzed separately. For male patients, the glenoid width was measured as: glenoid height × 0.50 + 7 mm (R 2 = 0.36; P < .001); for female patients, the glenoid width was measured as: glenoid height × 0.45 + 7 mm (R 2 = 0.31; P < .001). CONCLUSION: In an East Asian population, the mean glenoid height and width were 34.45 and 23.35 mm, respectively. The formulas that represent the relationship between glenoid width and height for male and female patients are the following: glenoid width = glenoid height × 0.50 + 7 mm and glenoid width = glenoid height × 0.45 + 7 mm, respectively.

Prevalence and associated factors of intra-articular lesions in acute ankle fractures evaluated by arthroscopy and clinical outcomes with minimum 24-month follow-up.

BACKGROUND: Acute ankle fractures can lead to high rate of concomitant intra-articular lesions which may compromise clinical results. The purpose of this study was to evaluate the incidence of concomitant intra-articular lesions in acute ankle fractures with arthroscopy. We also sought to analyze the relationship between intra-articular lesions and the fracture type, as well as the severity of the fracture. METHODS: It was a retrospective cohort study. From April 2014 to December 2015, we have chosen arthroscopy-assisted open reduction and internal fixation (AORIF) for the treatment of unstable acute ankle fractures. All concomitant intra-articular lesions were assessed and documented carefully and prospectively, such as ligament injuries, osteochondral lesions, and tibiofibular syndesmosis injuries. All fractures were classified according to the Lauge-Hansen classification system. The American Orthopedic Foot and Ankle Society's (AOFAS) ankle-hindfoot scale was used to assess post-operative function. Statistical comparisons between the intra-articular lesions, the fracture type, and the severity of the presenting fracture were performed using a Chi-squared analysis. RESULTS: Data of 36 patients were analyzed in the study, including 23 supination-type fractures and 13 pronation-type fractures. The incidence of tibiofibular syndesmosis injuries, chondral lesions, and loose bodies were 92%, 72%, and 39%, respectively. Avulsion fractures of the anterior tibiofibular syndesmosis were more commonly found in supination-type fractures than pronation-type fracture (45% vs. 15%, χ = 5.78, P = 0.02), which would cause mechanical blocking in the anterior portion of the ankle. On the contrary, chondral lesions were more commonly found in the more severe fractures than mild fractures (86% vs. 53%, χ = 4.57, P = 0.03). A mean 41.7 months (range, 33.0-51.0 months) of follow-up was achieved. A mean AOFAS's ankle-hindfoot scale was 96.9, and 97.2% of the patients were satisfied with the procedure. CONCLUSIONS: Acute ankle fractures have a high incidence of concomitant intra-articular lesions. Avulsion fractures of the anterior tibiofibular syndesmosis are more commonly found in supination-type fractures. Chondral lesions are related to the severity of the fractures, but not with the classification of the fractures. AORIF can be one reliable solution in dealing with the associated injuries seen with acute ankle fractures.

miR-206 inhibits osteogenic differentiation of bone marrow mesenchymal stem cells by targetting glutaminase.

Osteoblast-mediated bone formation is a complex process involving various pathways and regulatory factors, including cytokines, growth factors, and hormones. Investigating the regulatory mechanisms behind osteoblast differentiation is important for bone regeneration therapy. miRNAs are known as important regulators, not only in a variety of cellular processes, but also in the pathogenesis of bone diseases. In the present study, we investigated the potential roles of miR-206 during osteoblast differentiation. We report that miR-206 expression was significantly down-regulated in human bone marrow mesenchymal stem cells (BMSCs) at days 7 and 14 during osteogenic induction. Furthermore, miR-206 overexpressing BMSCs showed attenuated alkaline phosphatase (ALP) activity, Alizarin Red staining, and osteocalcin secretion. The mRNA levels of osteogenic markers, Runx2 and Osteopontin (OPN), were significantly down-regulated in miR-206 overexpressing BMSCs. We observed that significantly increased glutamine uptake at days 7 and 14 during the osteogenic induction and inhibition of glutamine metabolism by knocking down glutaminase (GLS)-suppressed osteogenic differentiation of BMSCs. Here, we discover that miR-206 could directly bind to the 3'-UTR region of GLS mRNA, resulting in suppressed GLS expression and glutamine metabolism. Finally, restoration of GLS in miR-206 overexpressing BMSCs led to recovery of glutamine metabolism and osteogenic differentiation. In summary, these results reveal a new insight into the mechanisms of the miR-206-mediated osteogenesis through regulating glutamine metabolism. Our study may contribute to the development of therapeutic agents against bone diseases.

What Role Does Low Bone Mineral Density Play in the "Killer Turn" Effect after Transtibial Posterior Cruciate Ligament Reconstruction?

OBJECTIVE: To explore the mechanism of the "killer turn", which is reported to be a reason for postoperative residual laxity after transtibial posterior cruciate ligament (PCL) reconstruction, in a low bone mineral density (BMD) condition. METHODS: A total of 80 skeletally mature female New Zealand white rabbits were included for biomechanical evaluation after transtibial PCL reconstructions. The subjects were equally divided into low BMD (n = 40) and control groups (n = 40). Rabbits in the low BMD group were treated with surgery and drug injection to establish an osteoporotic model. Rabbits in the control group received sham surgeries and no injection. All assignments were conducted randomly according to random numbers generated by a computer. All grafts were then subjected to biomechanical testing with an MTS model-858 Mini Bionix servohydraulic materials testing machine (MTS Systems, Minneapolis, Minnesota, USA). The experimental outcomes were the increment of total graft displacement, tunnel inlet enlargement, graft elongation, stiffness and failure load of the two groups, and the comparison between them. RESULTS: Among the 80 subjects, 1 subject of the low BMD group failed at the 30th cycle by proximal tibial fracture and 1 subject of the control group failed at the 20th cycle for the same reason. As a result, 39 subjects of the low BMD group and 39 subjects of the control group survived the cyclic loading test. Compared with the control group, the low BMD group demonstrated significantly larger total graft displacement ( P = 0.006) and tunnel inlet enlargement ( P = 0.041) than the control group. The number of subjects with less than 10% enlargement was significantly greater (57.1%) in the control group than in the low BMD group ( P = 0.004). In the load-to-failure test, 26 (66.7%) subjects in the low BMD group failed by proximal tibial fracture (around the tunnel), 6 (15.4%) at the mounting site, 5 (12.8%) at the fixation site, and only 2 (5.1%) failed at the "killer turn." In the control group, 20 (51.3%) failed at the "killer turn," 9 (23.1%) at the proximal tibia (around the tunnel), 5 (12.8%) at the mounting site, and 5 (12.8%) at the fixation site. There were significantly fewer failures (10.0%) at the "killer turn" ( P = 0.000) and 155.6% more for the para-tunnel fracture ( P = 0.000) in the low BMD group compared with the control group. CONCLUSIONS: The low BMD group demonstrated an inferior biomechanical outcome to the control group with the transtibial technique. With low BMD, the "killer turn" effect compromises the posterior tibial cortex by enlarging the tunnel inlet.

Arthroscopy-Assisted Surgery for Acute Ankle Fractures: A Systematic Review.

PURPOSE: To summarize the clinical findings of adult patients undergoing arthroscopy-assisted open reduction-internal fixation for acute ankle fractures. METHODS: A systematic electronic search of the PubMed databases was performed for all published literature on December 8, 2014. All English-language clinical studies on acute ankle fractures treated with arthroscopy-assisted open reduction-internal fixation were eligible for inclusion. Basic information related to the surgical procedure was collected. RESULTS: The search criteria initially identified 187 articles, and 10 studies were included in this systematic review. There were 2 prospective, randomized studies; 2 prognostic studies; and 6 case-series studies. There were a total of 861 patients included in this systematic review. Danis-Weber type B fractures (335 of 483 patients) and supination-external rotation fractures (187 of 366 patients) were the most common types of all the ankle fractures. Concomitant injuries were common: 63.3% of patients had chondral lesions, 60.9% had deltoid ligament injuries, and 77.9% had tibiofibular syndesmosis injuries. Lavage and debridement of the ankle joint were performed by almost all the surgeons. Chondral lesions were treated with shaving, excision, or microfracture. The mean American Orthopaedic Foot & Ankle Society hindfoot score was 91.7. Only mild complications were reported. CONCLUSIONS: Acute ankle fractures are commonly concomitant with multiple soft-tissue injuries in which arthroscopy may serve as a method for accurate diagnosis and appropriate treatment. LEVEL OF EVIDENCE: Level IV, systematic review of Level I, II, III, and IV studies.

Macroscopic and histological evaluations of meniscal allograft transplantation using gamma irradiated meniscus: a comparative in vivo animal study.

BACKGROUND: Many studies suggest that the gamma irradiation decreases allograft strength in a dose-dependent manner. However, no study has demonstrated that this decrease in strength translates into higher failure rate in meniscal allograft transplantation (MAT). The aim of this study was to investigate the effects of gamma irradiation on macroscopic and histological alterations of transplanted meniscal tissue and joint cartilage after MAT. METHODS: Medial total meniscectomies were performed on the right knees of 60 New Zealand white rabbits. All meniscal allografts were divided into three groups (20 in each group) and then sterilized with 0 Mrad, 1.5 Mrad, or 2.5 Mrad of gamma irradiation. For each group, 5 menisci were randomly chosen for scanning electron microscopic (SEM) analysis and the remaining 15 were prepared for MAT surgeries. Forty-five right knees received MAT surgeries (0 Mrad group, 1.5 Mrad group, 2.5 Mrad group, 15 in each group), whereas the remaining 15 only received medial meniscectomy (Meni group). The left knees of the Meni group were chosen as the Sham group (n = 15). All the rabbits were sacrificed at week 24 postoperatively. Cartilage of the medial compartment of each group was evaluated macroscopically using the International Cartilage Repair Society (ICRS) score and then histologically using the Mankin score based on the Masson Trichrome staining. RESULTS: The SEM analysis confirmed that the meniscal collagen fibers would be significantly damaged as the dose of gamma irradiation increased. At week 24, the overall scores of macroscopic evaluations of the transplanted meniscal tissue showed no significant differences among the three groups receiving MAT surgeries, except for 2 in the 2.5 Mrad group presented partial radial tears at midbody. The ICRS scores and the Mankin scores showed the lowest in the Sham group and the highest in the Meni group (P < 0.05). For the three groups receiving MAT surgeries, the 2.5 Mrad group showed significant higher ICRS scores and Mankin scores than both the 0 Mrad group and the 1.5 Mrad group (P < 0.05). Whereas the 1.5 Mrad group presented similar results to the 0 Mrad group concerning both the ICRS scores and the Mankin scores. CONCLUSIONS: The current in vivo animal study proved that although the meniscal collagen fibers were damaged after gamma irradiation, the failure rate of MAT surgeries might not significantly increase if the irradiation dose was <1.5 Mrad for New Zealand white rabbits.

Arthroscopy-assisted surgery for tibial plateau fractures.

PURPOSE: This study aimed to summarize the recent clinical outcomes of patients undergoing arthroscopy-assisted reduction and internal fixation (ARIF) for tibial plateau fractures. METHODS: A systematic electronic search of the PubMed and Cochrane databases was performed in January 2014. All English-language clinical studies on tibial plateau fractures treated with ARIF that were published after January 1, 2000 were eligible for inclusion. Basic information related to the surgery was collected. RESULTS: The search criteria initially identified 141 articles, and 19 studies were included in this systematic review. There were 2 retrospective comparative studies, 16 case series studies, and one clinical series based on a technique note. There were a total of 609 patients in this systematic review, with a mean follow-up time of 52.5 months. The most common fracture types were Schatzker types II and III. Concomitant injuries were common: 42.2% of the patients had meniscal injuries, and 21.3% had anterior cruciate ligament (ACL) injuries. In addition, the status of 90.5% of the patients was classified as good or excellent according to the clinical Rasmussen scoring system, and 90.9% of the patients were satisfied with the treatment. Only 6 severe complications were reported, including one case of compartment syndrome. CONCLUSIONS: ARIF is a reliable, effective, and safe method for the treatment of tibial plateau fractures, especially when they present with concomitant injuries. LEVEL OF EVIDENCE: Level IV, systematic review of Level III and Level IV studies.

Acute anterior cruciate ligament reconstruction with an augmented remnant repair: a comparative macroscopic and biomechanical study in an animal model.

PURPOSE: Our purpose was (1) to compare the structural integrity and healing capacity of the acutely repaired anterior cruciate ligament (ACL) remnants and (2) to determine whether the short-term postoperative biomechanical results of the acute remnant-repairing anterior cruciate ligament reconstruction (ACLR) were superior to the conventional ACLR. METHODS: An acute complete ACL femoral detachment model was created in 50 rabbits. The rabbits were immediately randomly allocated into the remnant-repairing ACLR group (group 1, n = 25) and the conventional ACLR group (group 2, n = 25). Each animal in both groups was subjected to unilateral ACLR with semitendinosus tendon autografts. During ACLR, the ACL remnants were acutely repaired with the femoral-tensioning technique in group 1, whereas the ACL remnants were debrided in group 2. The outcomes of the remnant were macroscopically evaluated in group 1. The remnant's structural integrity and remnant-to-graft healing capacity were divided into 3 categories (grade A, good; grade B, fair; or grade C, poor) according to 2 distinct criteria. Biomechanical tests including the anterior tibial translation test at 30° and 90° of knee flexion and tensile tests were compared between groups. All the macroscopic evaluations and biomechanical tests were performed postoperatively at week 12. RESULTS: The macroscopic evaluations of the ACL remnants in group 1 (n = 25) showed that the remnants' structural integrity was grade A (well-maintained continuity with an adequate amount of tissue and tension on probing) in 10 specimens (40%), grade B (fairly maintained continuity with thin and slack fibers detected) in 5 (20%), and grade C (resorption with no remnant left in situ) in 10 (40%). The remnant-to-graft healing capacities among the specimens with surviving remnants (grades A and B for structural integrity, n = 15) were all classified as grade C (an obvious remnant-to-graft interval through the entire length of the graft). For the biomechanical tests, there were no significant differences between the groups (25 in each group) with respect to the anterior tibial translation test at 30° (P = .15) and 90° (P = .91) of knee flexion and stiffness (P = .66), ultimate failure load (P = .11), and elongation at failure (P = .92). CONCLUSIONS: In our rabbit model of ACL femoral detachment, the acutely repaired ACL remnants showed a high resorption rate, low healing capacity, and poor biomechanical properties. The acute remnant-repairing ACLR had no evident superiority over the conventional ACLR in rabbits. CLINICAL RELEVANCE: The findings did not support the contention that the remnant-repairing ACLR, even performed in the acute setting, could produce better postoperative knee joint stability outcomes than the conventional ACLR.

The anterior cruciate ligament remnant: to leave it or not?

PURPOSE: The role of the anterior cruciate ligament remnant in anterior cruciate ligament reconstruction (ACLR) is debated. The purposes of this systematic review were (1) to summarize the clinical outcomes of patients undergoing remnant-preserving ACLR and (2) to investigate whether those outcomes were superior to standard ACLR. METHODS: The PubMed database was searched using specific inclusion and exclusion criteria for clinical studies reporting both preoperative conditions and postoperative outcomes of remnant-preserving ACLR. All reported postoperative complications were analyzed. In addition, a modified Coleman Methodology Score (CMS) system was used to assess the methodologic quality of the included studies. RESULTS: Thirteen studies were included with a mean CMS value of 71.7 (range, 57 to 92). In total, 546 patients underwent remnant-preserving ACLR by 3 different procedures: standard ACLR plus tibial remnant tensioning (n = 166), selective-bundle augmentation (n = 337), and standard ACLR plus tibial remnant sparing (n = 43). All clinical outcomes improved significantly (P < .05) at the final follow-up (mean, 27.9 months). Seven studies directly compared postoperative clinical outcomes between remnant-preserving ACLR and standard ACLR. In 6 of the 7 studies, similar postoperative clinical outcomes were reported between groups. One study reported superior clinical outcomes after remnant-preserving ACLR. There was no significant difference between groups regarding the overall rate of postoperative complications. CONCLUSIONS: The mean CMS showed moderate methodologic quality for the included studies. This systematic review showed significant postoperative improvements in patients undergoing remnant-preserving ACLR in all of the studies. However, further comparisons between remnant-preserving ACLR and standard ACLR showed inconsistent results in the 7 comparative studies, with 6 reporting equivalent postoperative clinical outcomes between groups. There was no significant difference in the rate of total complications between groups. The currently available evidence is not sufficiently strong to support the superiority of remnant-preserving ACLR. LEVEL OF EVIDENCE: Level IV, systematic review of Level I-IV studies.