Wanshou Guo

Recombinant human bone morphogenetic protein-2 in debridement and impacted bone graft for the treatment of femoral head osteonecrosis.

The purpose of this study was to compare the clinical outcomes of impacted bone graft with or without recombinant human bone morphogenetic protein-2 (rhBMP-2) for osteonecrosis of the femoral head (ONFH). We examined the effect of bone-grafting through a window at the femoral head-neck junction, known as the “light bulb” approach, for the treatment of ONFH with a combination of artificial bone (Novobone) mixed with or without rhBMP-2. A total of 42 patients (72 hips) were followed-up from 5 to 7.67 years (average of 6.1 years). The patients with and without BMP were the first group (IBG+rhBMP-2) and the second group (IBG), respectively. The clinical effectiveness was evaluated by Harris hip score (HHS). The radiographic follow-up was evaluated by pre-and postoperative X-ray and CT scan. Excellent, good, and fair functions were obtained in 36, 12, and 7 hips, respectively. The survival rate was 81.8% and 71.8% in the first and second group, respectively. However, the survival rate was 90.3% in ARCO stage IIb, c, and only 34.6% in ARCO stage IIIa(P<0.05). It was concluded that good and excellent mid-term follow-up could be achieved in selected patients with ONFH treated with impacted bone graft operation. The rhBMP-2 might improve the clinical efficacy and quality of bone repair.

The learning curve for minimally invasive Oxford phase 3 unicompartmental knee arthroplasty: cumulative summation test for learning curve (LC-CUSUM)

BackgroundThe minimally invasive Oxford unicompartmental knee arthroplasty (UKA) is a demanding procedure but has many advantages compared with total knee arthroplasty (TKA). The aim of this observational study was to investigate the learning curve of one experienced surgeon introducing minimally invasive Oxford phase 3 UKA into his routine clinical practice.MethodsThe first 50 consecutive cases of minimally invasive Oxford phase 3 UKA performed by one surgeon were evaluated to determine whether there was an association between outcomes and the cumulative number of cases performed, indicating the presence of learning curve. The cohort was divided into two groups: group A comprised the first 25 cases and group B cases 26–50. Duration of surgery, blood loss, Hospital for Special Surgery score, range of motion, complications, and the radiographical position of the implant were compared between the groups. The cumulative summation test for learning curve (LC-CUSUM) was then used to further analyze the learning curve.ResultsThe mean age and follow-up were 64.4 years and 50.9 months, respectively. The duration of surgery and blood loss were significantly more favorable in group B. The length of incision gradually reduced from 9.7 ± 1.3 to 8.5 ± 1.1 cm. Failures were identified in nine patients (18%). Two revisions and two dislocations were encountered in group A; one revision was performed 4 years after surgery for a patient in group B because of a fracture. One case of lateral compartment osteoarthritis was identified in group A. Two patients in each group reported continuing unexplained pains. CUSUM analysis showed that failure rates diminished rapidly after 16 cases and reached an acceptable rate after 29 cases.ConclusionsMinimally invasive Oxford phase 3 UKA for anteromedial osteoarthritis is a demanding procedure, but satisfactory outcomes can be achieved after approximately 25 cases.

Finite Element Analysis of Mobile-bearing Unicompartmental Knee Arthroplasty: The Influence of Tibial Component Coronal Alignment

Background: Controversies about the rational positioning of the tibial component in unicompartmental knee arthroplasty (UKA) still exist. Previous finite element (FE) studies were rare, and the results varied. This FE study aimed to analyze the influence of the tibial component coronal alignment on knee biomechanics in mobile-bearing UKA and find a ration range of inclination angles. Methods: A three-dimensional FE model of the intact knee was constructed from image data of one normal subject. A 1000 N compressive load was applied to the intact knee model for validating. Then a set of eleven UKA FE models was developed with the coronal inclination angles of the tibial tray ranging from 10° valgus to 10° varus. Tibial bone stresses and strains, contact pressures and load distribution in all UKA models were calculated and analyzed under the unified loading and boundary conditions. Results: Load distribution, contact pressures, and contact areas in intact knee model were validated. In UKA models, von Mises stress and compressive strain at proximal medial cortical bone increased significantly as the tibial tray was in valgus inclination >4°, which may increase the risk of residual pain. Compressive strains at tibial keel slot were above the high threshold with varus inclination >4°, which may result in greater risk of component migration. Tibial bone resection corner acted as a strain-raiser regardless of the inclination angles. Compressive strains at the resected surface slightly changed with the varying inclinations and were not supposed to induce bone resorption and component loosening. Contact pressures and load percentage in lateral compartment increased with the more varus inclination, which may lead to osteoarthritis progression. Conclusions: Static knee biomechanics after UKA can be greatly affected by tibial component coronal alignment. A range from 4° valgus to 4° varus inclination of tibial component can be recommended in mobile-bearing UKA.

Intractable Bone Marrow Edema Syndrome of the Hip

There is a need for an effective and noninvasive treatment for intractable bone marrow edema syndrome of the hip. Forty-six patients with intractable bone marrow edema syndrome of the hip were retrospectively studied to compare the short-term clinical effects of treatment with high-energy extracorporeal shock wave therapy vs femoral head core decompression. The postoperative visual analog scale score decreased significantly more in the extracorporeal shock wave therapy group compared with the femoral head core decompression group (P<.05). For unilateral lesions, postoperative Harris Hip Scores for all hips in the extracorporeal shock wave therapy group were more significantly improved than Harris Hip Scores for all hips in the femoral head core decompression group (P<.05). Patients who underwent extracorporeal shock wave therapy also resumed daily activities significantly earlier. Average overall operative time was similar in both groups. Symptoms disappeared significantly sooner in the extracorporeal shock wave therapy group in patients with both unilateral (P<.01) and bilateral lesions (P<.05). Hospital costs were significantly lower with extracorporeal shock wave therapy compared with femoral head core decompression. The intraoperative fluoroscopy radiation dose was lower in extracorporeal shock wave therapy than in femoral head core decompression for both unilateral (P<.05) and bilateral lesions (P<.01). On magnetic resonance imaging (MRI), bone marrow edema improved in all patients during the follow-up period. After extracorporeal shock wave therapy, all patients remained pain-free and had normal findings on posttreatment radiographs and MRI scans. Extracorporeal shock wave therapy appears to be a valid, reliable, and noninvasive tool for rapidly resolving intractable bone marrow edema syndrome of the hip, and it has a low complication rate and relatively low cost compared with other conservative and surgical treatment approaches.

Combined Tantalum Implant with Bone Grafting for the Treatment of Osteonecrosis of the Femoral Head

ABSTRACT Background: The purpose of this study was to evaluate the short-term clinical outcome of using a tantalum implant in combination with bone grafting for the treatment of osteonecrosis of the femoral head. Methods: Sixty-nine patients with 94 osteonecrotic hips were treated with this method from March 2006 to March 2011. All the patients were treated with tantalum rod implantation in combination with bone grafting, and were followed for an average 35.4 months. Harris hip score and the survival rate were analyzed according to stage, etiology, and osteonecrosis part. Results: Patients with stage I and stage II diseases had significant greater Harris hip score improvement than patients having stage III disease (p < .05). The survival rate was also significantly higher in patients with stage I and stage II diseases than in patients having stage III disease (p < .05). Patients with type A and type B necrotic lesions had better recovery than patients with type C1 and type C2 having lateral column lesions (p < .05). No significant differences were detected in the clinical outcome among patients with different etiologies. Conclusion: Combined tantalum implant with bone grafting provided good short-term clinical outcomes for early stage I and stage II patients with type A and type B necrotic lesions. However, this treatment modality was not so effective for patients with stage III or type C1 and type C2 necrotic lesions.

Early and middle term results after surgical treatment for slipped capital femoral epiphysis.

Objective:  To evaluate the early and middle‐term results of in situ single screw fixation and subtrochanteric osteotomy of the femur with external fixator for slipped capital femoral epiphysis (SCFE).

The influence of knee malalignment on the ankle alignment in varus and valgus gonarthrosis based on radiographic measurement

PURPOSE The lower limb misalignment as calculated by radiography has an evident effect on the development and progression of knee osteoarthritis (OA). However, whether the knee malalignment has an influence on ankle alignment is unknown. The purpose of this study was to discuss the correlation between knee and ankle alignment in varus and valgus gonarthrosis. METHODS This is a retrospective study of 149 patients with symptomatic varus and valgus knee OA who intend to take total knee arthroplasty (TKA) between January and October 2013. A protocol for the measurement of knee-ankle alignment and angles on full-length standing anteroposterior radiographs of the lower extremity was outlined in detail with step-by-step instructions. Two observers measured the angles chosen. The Pearsons correlation tests were used for the statistical analysis. RESULTS Pearsons correlation test results for unilateral varus or valgus gonarthrosis showed that the varus or valgus deformity of the knee can influence the tilt angle and tibiotalar angle of the ankle in operative side signficantly(p<0.05), and the tilt angle of the ankle can also be affected in nonoperative side (p<0.05). Moreover, the tilt angle of the bilateral ankle can be simultaneously affected in bilateral varus gonarthrosis (p<0.05). CONCLUSION These findings suggest that the varus and valgus deformity of the knee can induce the tilt of the ankle and influence the ankle alignment, which may further accelerate the degeneration of the ankle. Moreover, the knee alignment in the nonoperative side can also result in the change of ankle alignment at the same time.

Glucocorticoids Significantly Influence the Transcriptome of Bone Microvascular Endothelial Cells of Human Femoral Head

Background: Appropriate expression and regulation of the transcriptome, which mainly comprise of mRNAs and lncRNAs, are important for all biological and cellular processes including the physiological activities of bone microvascular endothelial cells (BMECs). Through an intricate intracellular signaling systems, the transcriptome regulates the pharmacological response of the cells. Although studies have elucidated the impact of glucocorticoids (GCs) cell-specific gene expression signatures, it remains necessary to comprehensively characterize the impact of lncRNAs to transcriptional changes. Methods: BMECs were divided into two groups. One was treated with GCs and the other left untreated as a paired control. Differential expression was analyzed with GeneSpring software V12.0 (Agilent, Santa Clara, CA, USA) and hierarchical clustering was conducted using Cluster 3.0 software. The Gene Ontology (GO) analysis was performed with Molecular Annotation System provided by CapitalBio Corporation. Results: Our results highlight the involvement of genes implicated in development, differentiation and apoptosis following GC stimulation. Elucidation of differential gene expression emphasizes the importance of regulatory gene networks induced by GCs. We identified 73 up-regulated and 166 down-regulated long noncoding RNAs, the expression of 107 of which significantly correlated with 172 mRNAs induced by hydrocortisone. Conclusions: Transcriptome analysis of BMECs from human samples was performed to identify specific gene networks induced by GCs. Our results identified complex RNA crosstalk underlying the pathogenesis of steroid-induced necrosis of femoral head.

Minimally invasive unicompartmental knee arthroplasty for spontaneous osteonecrosis of the knee.

To explore the outcome and surgical technique of minimally invasive unicompartmental knee arthroplasty (UKA) for spontaneous osteonecrosis of the knee.

Osteonecrosis in patients after severe acute respiratory syndrome (SARS): possible role of anticardiolipin antibodies.

Objectives:This study examined the anticardiolipin antibodies in post-SARS (severe acute respiratory syndrome) osteonecrosis patients to investigate the etiology of post-SARS osteonecrosis, and to eventually provide valuable information for the early diagnosis of nontraumatic osteonecrosis and for the susceptible population screening. Methods:This study recruited 62 post-SARS osteonecrosis patients and 52 age- and gender-matched healthy controls. Fasting blood samples were collected from all the subjects through cubital veins. Immunoglobulins A, G and M (IgA, G and M) types of anticardiolipin antibodies were examined by enzyme-linked immunosorbent assay. The routine examinations of prothrombin time, thrombin time, prothrombin activity, and international normalized ratio were also performed. Results:There were 21 of 62 post-SARS osteonecrosis patients (33.9%) who showed at least one type of anticardiolipin antibodies. The titers of specific IgA, IgG, and IgM were 11.33 ± 11.209 APL, 5.127 ± 5.927 GPL, and 17.821 ± 10.606 MPL, respectively. There were only 4 of 52 subjects in the control group (7.7%) who showed positive anticardiolipin antibody with titers of IgA at 10.702 ± 3.126 APL, IgG at 5.184 ± 4.780 GPL, and IgM at 14.684 ± 5.516 MPL. There were significant differences between the 2 groups confirmed by t-Test and &khgr;2 test (P < 0.05), while no significant differences were observed in prothrombin time, thrombin time, prothrombin activity, and international normalized ratio results between the 2 groups. Conclusions:The incidences of anticardiolipin antibodies were increased in the post-SARS osteonecrosis patients and anticardiolipin antibodies may play a role in the pathogenesis of post-SARS osteonecrosis.