Qidong Zhang

Comparison Between Closed Suction Drainage and Nondrainage in Total Knee Arthroplasty : A Meta-Analysis

From individual randomized studies, it is not clear whether a closed suction drainage should be used after total knee arthroplasty. Our meta-analysis compares the clinical outcomes of closed suction drainage with nondrainage after total knee arthroplasty in randomized controlled trials reported between January 1966 and May 2010. Fifteen eligible trials involving 1361 knee incisions (686 knees with closed suction drainage and 675 knees without drainage) satisfied the inclusion criteria for our meta-analysis. The result of the meta-analysis indicates that closed suction drainage reduces the incidence of soft tissue ecchymosis and requirement for dressing reinforcement, but increases the rate of homologous blood transfusion. No significant difference between drainage and nondrainage was observed in the incidence of infection, deep venous thrombosis, or postoperative range of motion.

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.

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.

Effect of glucocorticoids on miRNA expression spectrum of rat femoral head microcirculation endothelial cells

The study profiled the differential miRNA expression from femoral head bone microvascular endothelial cells (BMECs) between model group and control group to explore the pathogenesis of steroid-induced osteonecrosis of femoral head (ONFH). Twenty 8-week-old Female Sprague-Dawley (SD) rats were randomly divided into control and model groups. Rats in model group received an intraperitoneal injection of 20-μg/kg lipopolysaccharide (LPS) at an interval of 24 h. Then, 24 h later, rats received three doses of 40-mg/kg methylprednisolone by intramuscular injection at intervals of 24 h. In control group, rats received the same volume of normal saline. After 4 weeks, the femoral heads were sectioned to confirm the establishment of the model. To replicate the animal model ex vivo, BMECs were isolated. Different miRNAs were screened using Agilent Gene Spring GX software, and real-time quantitative polymerase chain reaction (qPCR) was used to confirm the results of miRNA microarray analysis. The differentially expressed miRNA were assessed by bioinformatics analysis. Four differentially expressed miRNAs were identified (two upregulated: miR-132-3p, miR-335 and two down regulated: miR-466b-2-3p, let-7c-1-3p). qPCR results were consistent with the gene-chip results. Steroid-induced ONFH may cause miRNA changes in BMSCs. miR-132-3p and miR-335 may be important in steroid-induced ONFH.

Significance of Lateral Pillar in Osteonecrosis of Femoral Head: A Finite Element Analysis.

Background: The lateral pillar of the femoral head is an important site for disease development such as osteonecrosis of the femoral head. The femoral head consists of medial, central, and lateral pillars. This study aimed to determine the biomechanical effects of early osteonecrosis in pillars of the femoral head via a finite element (FE) analysis. Methods: A three-dimensional FE model of the intact hip joint was constructed from the image data of a healthy control. Further, a set of six early osteonecrosis models was developed based on the three-pillar classification. The von Mises stress and surface displacements were calculated for all models. Results: The peak values of von Mises stress in the cortical and cancellous bones of normal model were 6.41 MPa and 0.49 MPa, respectively. In models with necrotic lesions in the cortical and cancellous bones, the von Mises stress and displacement of lateral pillar showed significant variability: the stress of cortical bone decreased from 6.41 MPa to 1.51 MPa (76.0% reduction), while cancellous bone showed an increase from 0.49 MPa to 1.28 MPa (159.0% increase); surface displacements of cortical and cancellous bones increased from 52.4 &mgr;m and 52.1 &mgr;m to 67.9 &mgr;m (29.5%) and 61.9 &mgr;m (18.8%), respectively. In addition, osteonecrosis affected not only pillars but also adjacent structures in terms of the von Mises stress and surface displacement levels. Conclusions: This study suggested that the early-stage necrosis in the femoral head could increase the risk of collapse, especially in lateral pillar. On the other hand, the cortical part of lateral pillar was found to be the main biomechanical support of femoral head.

Effects of Lower Limb Alignment and Tibial Component Inclination on the Biomechanics of Lateral Compartment in Unicompartmental Knee Arthroplasty

Background: Lateral compartmental osteoarthritis (LCOA), a major complication after medial mobile-bearing unicompartmental knee arthroplasty (UKA), is highly associated with the increased stress of the lateral compartment. This study aimed to analyze the effects on the stress and load distribution of the lateral compartment induced by lower limb alignment and coronal inclination of the tibial component in UKA through a finite element analysis. Methods: Eight three-dimensional models were constructed based on a validated model for analyzing the biomechanical effects of implantation parameters on the lateral compartment after medial Oxford UKA: postoperative lower limb alignment of 3° valgus, neutral and 3° varus, and the inclination of tibial components placed in 4°, 2° valgus, square, and 2° and 4° varus. The contact stress of femoral and tibial cartilage and load distribution were calculated for all models. Results: In the 3° valgus lower limb alignment model, the contact stress of femoral (3.38 MPa) and tibial (3.50 MPa) cartilage as well as load percentage (45.78%) was highest compared to any other model, and was increased by 36.75%, 47.70%, and 27.63%, respectively when compared to 3° varus. In the condition of a neutral position, the outcome was comparable for the different tibial tray inclination models. The inclination did not greatly affect the lateral compartmental stress and load distribution. Conclusions: This study suggested that slightly varus (undercorrection) lower limb alignment might be a way to prevent LCOA in medial mobile-bearing UKA. However, the inclination (4° varus to 4° valgus) of the tibial component in the coronal plane would not be a risk factor for LCOA in neutral position.

Glycosaminoglycan Content of the Lateral Compartment Cartilage in Knees Conforming to the Indications for Oxford Medial Unicompartmental Knee Arthroplasty

Background: The quality of the lateral compartment cartilage is important to preoperative evaluation and prognostic prediction of unicompartmental knee arthroplasty (UKA). Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) enables noninvasive assessment of glycosaminoglycan (GAG) content in cartilage. This study aimed to determine the GAG content of the lateral compartment cartilage in knees scheduled to undergo Oxford medial UKA. Methods: From December 2016 to May 2017, twenty patients (20 osteoarthritic knees) conforming to the indications for Oxford medial UKA were included as the osteoarthritis (OA) group, and 20 healthy volunteers (20 knees) paired by sex, knee side, age (±3 years), and body mass index (BMI) (±3 kg/m2) were included as the control group. The GAG contents of the weight-bearing femoral cartilage (wbFC), the posterior non-weight-bearing femoral cartilage (pFC), the lateral femoral cartilage (FC), and tibial cartilage (TC) were detected using dGEMRIC. The dGEMRIC indices (T1Gd) were calculated in the middle three consecutive slices of the lateral compartment. Paired t-tests were used to compare the T1Gd in each region of interest between the OA group and control group. Results: The average age and BMI in the two groups were similar. In the OA group, T1Gd of FC and TC was 386.7 ± 50.7 ms and 429.6 ± 59.9 ms, respectively. In the control group, T1Gd of FC and TC was 397.5 ± 52.3 ms and 448.6 ± 62.5 ms, respectively. The respective T1Gd of wbFC and pFC was 380.0 ± 47.8 ms and 391.0 ± 66.3 ms in the OA group and 400.3 ± 51.5 ms and 393.6 ± 57.9 ms in the control group. Although the T1Gd of wbFC and TC tended to be lower in the OA group than the control group, there was no significant difference between groups in the T1Gd in any of the analyzed cartilage regions (P value of wbFC, pFC, FC, and TC was 0.236, 0.857, 0.465, and 0.324, respectively). Conclusions: The GAG content of the lateral compartment cartilage in knees conforming to indications for Oxford medial UKA is similar with those of age- and BMI-matched participants without OA.

The Glycosaminoglycan Content of Hip Cartilage in Osteonecrosis of Femoral Head: Evaluation with Delayed Gadolinium-Enhanced Magnetic Resonance Imaging of Cartilage

Objective Hip cartilage quality is essential for the success of joint-preserving surgery for osteonecrosis. This study aimed to characterize cartilage changes in osteonecrosis of femoral head (ONFH) using delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC). Design Fifteen asymptomatic (control) and 60 ONFH subjects were included in this study. The ONFH subjects were stratified in accordance with the Association Research Circulation Osseous (ARCO) classification (n = 15 hips per ARCO stage). All participant hips were investigated using dGEMRIC and theT1Gd data were collected and analyzed. Results T1Gd value was significantly lower in the ONFH group (365.1 ± 90.5 ms; range 200-498 ms) compared with the control group (546.1 ± 26.0 ms; range 504-580 ms) (P < 0.001). The T1Gd values of ARCO stage I-IV ONFH were 460.2 ± 17.3 ms (439-498 ms), 408.9 ± 43.4 ms (337-472 ms), 359.9 ± 34.5 ms (303-412 ms), 231.5 ± 15.1 ms (200-253 ms), respectively. Decreased T1Gd value was found to correlate significantly with increased ONFH severity (P < 0.001). T1Gd value in collapse stage was significantly lower than that of noncollapse stage (295.7 ± 70.3 ms [range 200-412 ms] vs. 434.6 ± 41.7 ms [range 337-498 ms]; P < 0.001). Conclusions dGEMRIC identified hip cartilage as abnormal in ONFH, even at early-stage, as represented by decreased T1Gd, and this was further aggravated by ONFH collapse.