Hot issues related to modern hip prosthetic materials / 医学研究生学报

Artificial prosthetic material is one of the important factors determining the effect of artificial hip replacement.There are mainly three types of interfaces in the prosthetic materials: the fixed in-terface,the friction interface,and the interface between the modular prostheses.Porous metals improve the osseointegration of the bio-logical fixed interface.High crosslinking polyethylene and composite ceramics significantly reduce the wear of the friction interface.The modular prostheses of ceramic ball head can reduce the wear particles and corrosion.However,the prosthesis loosening,wear and metal corrosion are still the most important factors affecting the medium-long term effects of artificial hip replacement.This article reviews the research progress of artificial hip prosthesis materials from the perspective of the three prosthetic interfaces.

Efficacy and Safety of Zhuanggu Joint Capsules in Combination with Celecoxib in Knee Osteoarthritis: A Multi-center, Randomized, Double-blind, Double-dummy, and Parallel Controlled Trial / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Knee osteoarthritis (KOA) is a chronic joint disease that manifests as knee pain as well as different degrees of lower limb swelling, stiffness, and movement disorders. The therapeutic goal is to alleviate or eliminate pain, correct deformities, improve or restore joint functions, and improve the quality of life. This study aimed to evaluate the efficacy and safety of Zhuanggu joint capsules combined with celecoxib and the benefit of treatment with Zhuanggu alone for KOA.</p><p><b>METHODS</b>This multi-center, randomized, double-blind, double-dummy, parallel controlled trial, started from December 2011 to May 2014, was carried out in 6 cities, including Beijing, Shanghai, Chongqing, Changchun, Chengdu, and Nanjing. A total of 432 patients with KOA were divided into three groups (144 cases in each group). The groups were treated, respectively, with Zhuanggu joint capsules combined with celecoxib capsule simulants, Zhuanggu joint capsules combined with celecoxib capsules, and celecoxib capsules combined with Zhuanggu joint capsule simulants for 4 weeks consecutively. The improvement of Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index and the decreased rates in each dimension of WOMAC were evaluated before and after the treatment. Intergroup and intragroup comparisons of quantitative indices were performed. Statistically significant differences were evaluated with pairwise comparisons using Chi-square test (or Fisher's exact test) and an inspection level of α = 0.0167.</p><p><b>RESULTS</b>Four weeks after treatment, the total efficacies of Zhuanggu group, combination group, and celecoxib group were 65%, 80%, and 64%, respectively, with statistically significant differences among the three groups (P = 0.005). Intergroup pairwise comparisons showed that the total efficacy of the combination group was significantly higher than that of the Zhuanggu (P = 0.005) and celecoxib (P = 0.003) groups. The difference between the latter two groups was not statistically significant (P > 0.0167). Four weeks after discontinuation, the efficacies of the three groups were 78%, 95%, and 65%, respectively, with statistically significant differences (P < 0.0001). Intergroup pairwise comparisons revealed that the efficacy of the combination group was significantly better than that of the Zhuanggu and the celecoxib groups (P < 0.0001). The difference between the latter two groups was not statistically significant (P > 0.0167). The incidences of adverse events in Zhuanggu group, combination group, and celecoxib group were 8.5%, 8.5%, and 11.1%, respectively, with insignificant differences (P > 0.05).</p><p><b>CONCLUSIONS</b>Zhuanggu joint capsules alone or combined with celecoxib showed clinical efficacy in the treatment of KOA. The safety of Zhuanggu joint capsules alone or combined with celecoxib was acceptable.</p><p><b>TRIAL REGISTRATION</b>Chinese Clinical Trial Registry, ChiCTR-IPR-15007267; http://www.medresman.org/uc/project/projectedit.aspx?proj=1364.</p>

Changes in Intra-pelvic Obliquity Angle 0-2 Years After Total Hip Arthroplasty and Its Effects on Leg Length Discrepancy: A Retrospective Study / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Total hip arthroplasty (THA) is one of the most effective treatments for phase III and IV hip arthrosis. Lower limb length balancing is one of the determining factors of a successful surgery, particularly in patients with developmental dysplasia of the hip (DDH). The purpose of this study was to evaluate the postoperative change in intra-pelvic obliquity (intra-PO) angle in the coronal plane and its effects on leg length discrepancy (LLD) within 2 years.</p><p><b>METHODS</b>A total of 78 patients (70 females, 8 males) were enrolled in this study. All patients were suffering from DDH with varying degrees of LLD. Pelvic plain radiographs were collected before and after the operation. The intra-PO angles were measured 0, 0.5, 1 and 2 years after THA. At the same time, postoperative LLD was measured with blocking test.</p><p><b>RESULTS</b>PO changed significantly in the first year after THA surgery (0 year vs. 0.5 year, P < 0.01; 0.5 year vs. 1 year, P < 0.01), and the changing value of intra-PO angle (ΔPO) slowed down substantially during the first 2 years after THA (0.5 year vs. 0.5-1 year, P < 0.01; 0.5-1 year vs. 1-2 years, P < 0.01). With the change in intra-PO angle, LLD also got narrow within the 1st year (0 year vs. 0.5 year, P < 0.01; 0.5 year vs. 1 year, P < 0.01). Elderly patients had a smaller intra-PO angle reduction (Group A vs. Group B, P = 0.01; Group B vs. Group C, P < 0.01).</p><p><b>CONCLUSIONS</b>Intra-PO angle and LLD gap narrowed with time after THA surgery. In particular, elderly patients had smaller change in intra-PO angle.</p>

Effect of beta-tricalcium phosphate/poly-l-lactide composites on radial bone defects of rabbit

OBJECTIVE@#To explore the effect ofβ-TCP/PLLA scaffold in repairing rabbit radial bone defects.@*METHODS@#Thirty New Zealand rabbits were divided into β-TCP /PLLA group (group A), pure PLLA group (group B) and contrast group (group C) randomly. The rabbits were sacrificed respectively after 4, 8, 12, 24 weeks and the X-ray film was performed at the same time to evaluate the repair effect in different groups.@*RESULTS@#X-ray film showed there was uneven low density bone callus development in defect region after 4 weeks in group A. The defect region was filled with neonate osseous tissue completely during 12-24 weeks. X-ray score revealed that repair of bone defect results significantly better than group B and group C.@*CONCLUSIONS@#The β-TCP /PLLA composite is capable of repairing radial bone bone defects. β-TCP/PLLA scaffold is significant because of rapid degradation ability, good histocompatibility and osteogenic action.

Anatomical references for tibial sagittal alignment in total knee arthroplasty: a comparison of three anatomical axes based on 3D reconstructed CT images / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>This study was designed to analyze three tibial axis reference lines including the anterior tibial cortex (ATC) line, the fibular line (FL), and the anatomical axis of tibia (AAT) line, to determine which line most closely parallels the mechanical axis (MA) of the tibia in the sagittal plane. The clinical relevance of the study is that through finding a reliable landmark on the leg, a surgeon may minimize posterior tibial slope measurement errors thereby and improving the technique for assuring proper alignment of total knee arthroplasty.</p><p><b>METHODS</b>The material for this study included CT scans of the tibia from 85 consecutive patients and 168 knees (78 without osteoarthritis (OA) and 90 knees with OA). Measurements of the angles between the tibial mechanical axis and each of three reference lines in the sagittal plane were carried out using 3D imaging software.</p><p><b>RESULTS</b>Mean angles of 168 knees were as follows: aMT (3.96±0.85)°, aMF (0.70±0.58)°, and aMA (1.40±0.66)°, (aMT: an angle between MA and ATC, aMF: an angle between MA and FL, aMA: an angle between MA and AAT. All abovementioned angles were measured in the sagittal plane of tibia) and the aMF was significantly smaller than the others (P < 0.0001). The mean value of the medial tibial slope angle vs. the MA was (9.19±3.97)°, and this was significantly larger than the mean lateral slope angle of (6.62±4.23)° (P < 0.0001). The difference between aMF without OA and with OA was not statistically significant (P = 0.5015) and the association between the aMT and aMA was strong (r = 0.82, P < 0.01).</p><p><b>CONCLUSIONS</b>FL was more closely parallel to the MA of tibia, and more showed less variation between OA and non- OA controls than ATC and AAT lines. Furthermore, the amount of posterior slope in medial plateau was greater than that in lateral plateau. The findings of this analysis suggest that when using the anterior tibial cortex line as is commonly done with extramedullary tibial resection guides, the tibial resection should be sloped approximately four degrees more posteriorly.</p>

Rotational alignment in total knee arthroplasty: nonimage-based navigation system versus conventional technique / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Proper rotational alignment during total knee arthroplasty (TKA) is important for adequate postoperative patellofemoral and tibiofemoral kinematics, as well as for achieving balanced flexion space at 90. The effects of computer navigation-assisted total knee replacement and conventional total knee arthroplasty on rotational alignment, mechanical axis, component position and clinical outcomes were compared.</p><p><b>METHODS</b>Two methods were used in 82 patients and the rotation of the femoral and tibial components in the transverse plane, the combined rotation of the two components, the mismatch between them, and the mechanical axis of the lower limb were analyzed. All of these parameters were measured from postoperative radiographs and computed tomography images. Functional outcomes were compared at 6 weeks and 6 months postoperatively.</p><p><b>RESULTS</b>Significant differences were found between the two techniques (P < 0.05) in the following parameters: average rotation of the femoral component ((1.51 ± 3.55)° vs. (-0.63 ± 3.04)°); combined rotation of the femoral and tibial components (2.85 ± 4.07)° vs. (0.28 ± 3.43)°); and mismatch between the femoral and tibial components ((1.44 ± 4.55)° vs. (-0.43 ± 2.86)°). Differences in the rotation of the tibial component were not statistically significant. The prevalence of outliers (malalignment > ± 3° internal/external rotation) of the femoral component (31.7% vs. 12.5%) and the tibial component (36.6% vs. 15%) were significantly reduced when the navigation system was used (P < 0.05). In addition, while patients in the navigation group had significantly better mechanical axis and functional outcomes at 6 weeks after surgery (P < 0.05), there was no significant difference between the two groups (P > 0.05) with respect to functional outcomes at 6 months.</p><p><b>CONCLUSION</b>The navigation system exhibited higher accuracy than the conventional technique in the transverse and coronal plane, and provided better early functional outcomes.</p>

Needle acupuncture for osteoarthritis of the knee: a systematic review and updated meta-analysis

To evaluate the efficacy of treatment with acupuncture for knee osteoarthritis. We searched PUBMED, EMBASE, and the Cochrane Central Register of Controlled Trials databases from July to October 2011 for randomized controlled trials that compared needle acupuncture with sham acupuncture, standard care, or waiting list control groups in patients with knee osteoarthritis. Of the 490 potentially relevant articles, 14 RCTs involving 3,835 patients were included in the metaanalysis. Two authors independently extracted outcome data on short-term and long-term pain and functional measures. Standardized mean differences and 95% confidence intervals were calculated using the mean differences in improvements from baseline and the associated standard deviations in patients assigned to acupuncture and those assigned to control groups according to measurement time points. Compared with sham acupuncture control treatment, acupuncture was significantly better at relieving pain [p=0.002] and restoring function [p=0.01] in the short-term period, and relieving pain [p=0.06] and restoring function [p=0.06] in the long-term. Compared with the standard care and waiting list control treatments, acupuncture was significantly better at relieving pain and restoring function. Acupuncture provided significantly better relief from knee osteoarthritis pain and a larger improvement in function than sham acupuncture, standard care treatment, or waiting for further treatment.

Cementless two-staged total hip arthroplasty for chronic periprosthetic infection / 中华外科杂志

<p><b>OBJECTIVE</b>To determine the clinical outcomes of two-staged cementless revision arthroplasty for the treatment of deep periprosthetic infection after total hip arthroplasty.</p><p><b>METHODS</b>Twenty-three patients with deep periprosthetic infection treated with a standard protocol of two-staged cementless revision hip arthroplasty were enrolled in this study. There were 9 male patients and 14 female patients with an average age of 64 years (range, 52-78 years). In all cases, antibiotics-loaded cement spacers were implanted after removal of all the prosthetic components and thorough debridements had been done. All patients had a minimum of 2 weeks of intravenous antibiotics followed by 4 weeks of oral antibiotics after implant removal. After a mean interval of 6.7 months (3-28 months), revision arthroplasties were carried out with cementless femoral components followed by 2 weeks of intravenous antibiotics and 4 weeks of oral antibiotics.</p><p><b>RESULTS</b>The mean follow-up period was (4.3±3.5) years. There were 2 cases of recurrent infections in this study. Intraoperative periprosthetic fractures were observed in 3 patients. One patient had dislocation of the implanted spacer during the interval period and 2 patients had hip dislocation after reimplantation. Mild subsidence of femoral component occurred in 1 patient. There were no cases of loosening of femoral components and cementless acetabular components in patients without infection recurrence. The Harris hip score increased from a preoperative mean of 36±13 to 85±13 at 12 months after reimplantation.</p><p><b>CONCLUSIONS</b>Using cementless prostheses in two-staged revisions of hip periprosthetic infections can provide low rate of infection recurrence and good implant stability, but cautions must be taken when treating patients with infection caused by multidrug-resistant organisms.</p>

Activation of nuclear factor kappaB signaling pathway in human osteoblasts responses to Staphylococcus aureus in vitro / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate whether S. aureus could activate NF-κB signaling pathway in human osteoblasts.</p><p><b>METHODS</b>Immunoblot and electrophoretic mobility shift assay were used to detect the degradation of I-κBα and activation of NF-κB in human osteoblasts following infection with S.aureus, respectively, and there were investigated the activated state of NF-κB signaling pathway in human osteoblasts. In addition, enzyme-linked immunosorbent assay was used to measure the secretion of IL-6 in culture supernatants, which was represented as one of important cytokines in osteomyelitis, and an inhibitor of NF-κB, SN50, which was added to human osteoblasts culture prior to 1 hour at 50 µmol/L before the infection of S.aureus, was used to determine whether S.aureus-activated NF-κB signaling pathway regulates IL-6 secretion of human osteoblasts.</p><p><b>RESULTS</b>S.aureus could induce the degradation of I-κBα (I-κBα(15 min)/I-κBα(0 min) = 0.409 ± 0.245 and I-κBα(30 min)/I-κBα(0 min) = 0.061 ± 0.010) and activation of NF-κB in human osteoblasts in a time and dose-dependent manner following infection. In addition, the secretion of IL-6 in the supernatants of human osteoblasts ((2.17 ± 0.11) µg/L) was suppressed by 50 µmol/L SN50 compared to without the addition of SN50 ((3.58 ± 0.31) µg/L) (F = 174.25, P < 0.05).</p><p><b>CONCLUSIONS</b>S.aureus could activate NF-κB signaling pathway in human osteoblasts, which could regulate cytokines secretions of human osteoblasts.</p>

Gait analysis of patients with metal-on-metal resurfacing hip arthroplasty compared with big-femoral-head total hip arthroplasty

To evaluate gait patterns in patients with metal-on-metal resurfacing hip arthroplasty [RHA] compared with big-femoral-head total hip arthroplasty [BHA] at one year postoperatively. In this retrospective comparative observational study, 2 groups of 30 resurfacing hip arthroplasty [RHA] and big-femoral-head total hip arthroplasty [BHA] patients participated between June 2006 and March 2009 in the Sixth Affiliated People's Hospital, Shanghai Jiaotong University, Shanghai, China. Gait parameters and range of motion [ROM] in gait cycles were measured by Vicon gait analysis system and were used to calculate operated/contralateral ratios. No significant difference was found between gait parameter ratios, Hospital for Special Surgery Score [HSS], and University of California at Los Angeles Score [UCLA] of the 2 groups. However, there was significant difference between ROM ratios in gait cycles. Range of motions of operated hip joint were more similar to that of contra-lateral side in RHA group [hip flexion/extension p=0.007, hip abduction/adductionp=0.005, hip rotation p=0.006, knee flexion/extension p=0.037]. Gait parameters of patients who underwent RHA and BHA are approaching to normal values at one year postoperatively. At the time point, ROMs of RHA patients are larger than that of BHA patients during walking

Acetabular revision with impacted irradiated frozen allografts / 中华外科杂志

<p><b>OBJECTIVE</b>To analyze the clinical and radiographical result of acetabular revisions with wire mesh, impacted irradiated frozen allografts and cemented cups.</p><p><b>METHODS</b>From February 2006 to January 2009, a total of 20 patients with 21 acetabular revisions were performed with wire mesh, impacted irradiated frozen allografts and cemented cups. Eighteen cases (19 hips) were followed up. There were 5 hips in 4 males and 14 hips in 14 females. The average age of patients was 64.4 years (43 to 81 years). Acetabular bone defects were classified according to Paprosky classification. There were Paprosky II B in 4 hips, Paprosky II C in 8 hips, Paprosky IIIA in 5 hips and Paprosky IIIB in 2 hips. Wire mesh was used to converted segmental defects into cavity defects. Irradiated frozen allografts were impacted and cemented cup was inserted to complete the revision. Patients were followed up regularly with clinical and radiographical assessment. Harris score, migration and loosening of prosthesis grafts integration and complications were observed.</p><p><b>RESULTS</b>The average follow-up time was 22.4 months (12 - 48 months). Harris score improved from 42.5 points (31 - 56 points) pre-operation to 88.6 points (82 - 96 points) at the final follow up. Pain score was 14.4 point (10 - 20 point) before revision and 42.3 points (40 - 44 point) at the final follow up.</p><p><b>COMPLICATIONS</b>there was 1 infection and healing after debridement. One patient had weakness of quadriceps and returned to normal after 1 year. Greater trochanter fracture occurred in 1 patient. Cup migration and loosening were observed in 1 Paprosky IIIB patients. There was no cup migration more than 1 mm or change of abduction angle in the remaining 18 hips. Grafts incorporation defined as the presence of trabecular bone crossing the graft-host bond could also be seen in these 18 hips.</p><p><b>CONCLUSIONS</b>Impacted bone grafting technique combined with wire mesh and cemented cup is an effective method for biological acetabular revision. Irradiated frozen allografts implanted with impaction bone grafting technique can integrate with the surrounding host bone.</p>

Posterior longitudinal strip osteotomy of proximal femur in revision total hip arthroplasty / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate the treatment and effect of a technique using single femoral posterior longitudinal strip osteotomy in revision total hip arthroplasties.</p><p><b>METHODS</b>Between September 2005 and December 2009, 35 hips of 35 patients underwent a revision total hip arthroplasties (THA) in conjunction with extraction of femoral components. Among them, 23 cases were with uncemented, and 12 cases were with cemented femoral components. Those cases being followed up were chosen by two standards described as follows: one was the examination of preoperative radiographs, which showed that there was difficult in the extraction of the femoral components; Another followed was the trying with routine procedure to remove the stem. If these were unsuccessful, a single longitudinal strip osteotomy was performed, whose length was about 11 - 14 cm, and width was about 1 cm. Then the femoral component was disimpact. The osteotomy was fixed with wires or cables. If there was cortical deficiency or insufficient cancellous bone, grafting was performed. A cementless composite revision prosthesis of the Lima-Lto with a tapered modular distal fixation stem was used. All the patients were evaluated with preoperative and postoperative Harris score, the length of limb and radiographs.</p><p><b>RESULTS</b>All cases were followed up with 5 to 55 months, average 15 months. Compared with preoperative, the average Harris score increased from 30 (range, 19 - 40 points) to 85 points (range, 80 - 92 points). All pains of hip joint were alleviated from the mean 12 points (range, 10 - 20 points) before the operation to 40 points (range, 30 - 44 points) after the operation. All the femoral osteotomy and bone grafting were healing ultimately. And on average, the healing began in 20 weeks (range, 10 - 32 weeks). All the cases remain the same length of lower limbs. There was no hip joint dislocation, loosening or infection.</p><p><b>CONCLUSIONS</b>The femoral posterior longitudinal strip osteotomy facilitates the exposure and extraction of the femoral stem, the clear up of medullary cavity and then the femoral reconstruction in revision total hip arthroplasties. It has satisfactory short-term radiographic evaluation and clinical effect as a simple, effective and reliable technique.</p>

Total knee arthroplasty using computer assisted navigation in patients with severe valgus deformity of the knee / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Severe valgus deformity often has bone defect and laxity of the medial ligamentous, and total knee arthroplasty in severe valgus knee is, in most cases, more challenging for surgeons. The usefulness of a computer assisted navigation system in reestablishing the mechanical axis has been well established. Hence, the interest for surgeons is how the navigation system makes the procedure of total knee arthroplasty with severe valgus knee easier.</p><p><b>METHODS</b>From June 2006 to March 2008 in Department of Joint Surgery, Shanghai Sixth People's Hospital, 6 patients (7 knees) with severe valgus knee underwent total knee arthroplasty using the Stryker Navigation system, which is an active wireless and imageless system. All the patients were followed up for 12 to 18 months after surgery. The X-ray radiographs for whole limbs were obtained on all patients to determine preoperative and postoperative alignments.</p><p><b>RESULTS</b>A primary, posterior stabilized prosthesis was utilized in all cases. The average preoperative overall mechanical axis of the seven knees was 19.6° ± 4.6° of valgus (range 16° to 29°), and the average postoperative mechanical axis was 0.4° ± 0.7° (range 0.8° varus to 1.4° valgus).</p><p><b>CONCLUSIONS</b>The navigation system is a very effective and useful tool for accurate intraoperative restoration of alignment in the face of significant deformity with valgus knee. To prevent component malposition, we did not reduce the knee before solidification of bone cement but controlled alignment using the navigation system up to implantation of the final component.</p>

contour of cementless femoral stem has minor effect on initial periprosthetic von Mises stress distribution: a 3- dimensonal finite element analysis

To evaluate periprosthetic von Mises stress distribution with cementless femoral stems of various contours. The study was carried out at the Department of Orthopaedics, Shanghai 6th Hospital, Shanghai, China between May 2008 and February 2009. Finite element models of proximal femoral replacement with 4 cementless stems [Alloclassic, Ribbed Anatomic, VerSys, and Securi-fit] of various contours were set up. Under the loading conditions of walking and stair climbing, 3-dimensional periprosthetic von Mises stresses were calculated, and the stress distribution patterns were compared. Periprosthetic stresses were increased in level 1, 2, and 3 under the 2 loading conditions, and more considerably in level 2 and 3. The stresses were higher on the medial side in all cases. No remarkable difference was found in the patterns between the 4 stems. The contour design of femoral stem has minor effect on initial periprosthetic von Mises stress distribution

Locally administered lentivirus-mediated siRNA inhibits wear debris-induced inflammation / 中华外科杂志

<p><b>OBJECTIVE</b>To determine the safety and efficacy of local administration of lentivirus-mediated small interfering RNA (siRNA) targeting tumor necrosis factor-alpha (TNF-alpha) in murine air pouch model.</p><p><b>METHODS</b>From May 2007 to April 2008 a siRNA targeting TNF-alpha and a missense siRNA were designed, and recombine lentivirus which coexpressed the green fluorescent protein (GFP) as a marker gene was constructed. Air pouches were established and stimulated by Ti-6Al-4V particles. Pouches were divided into 3 groups randomly. Lentivirus-mediated siRNA targeting TNF-alpha (TNF-alpha group) or lentivirus-mediated missense siRNA (MS group), or virus-free saline (control group) were injected into pouches respectively. Pouch membrane, peripheral blood, heart, liver, spleen, kidney, lung and brain were harvested at 28 d after transfection, and assayed for markers of inflammation using histological, molecular, immunological techniques and Xenogen in vivo imaging system (IVIS) 50 vivo bioluminescent assay system.</p><p><b>RESULTS</b>Xenogen IVIS 50 vivo image revealed strong expression of GFP localized in pouch areas and no expression in other parts of mice both in TNF-alpha group and MS group at 4 weeks after transfection, while no expression of GFP was found in control group. By RT-PCR and ELISA, the mRNA and protein levels of TNF-alpha in TNF-alpha group decreased by 81.6% and 82.6% respectively compared to control group (P < 0.01), and decreased by 78.9% and 84.0% respectively compared to MS group (P < 0.01), whereas TNF-alpha level in peripheral blood, heart, liver, spleen, kidney, lung and brain remained invariant (P > 0.05). Less inflammatory responses (thinner pouch membrane and decreased cellular infiltration) were observed in TNF-alpha group.</p><p><b>CONCLUSION</b>Efficient local delivery of lentivirus-mediated siRNA targeting TNF-alpha into modified murine air pouch can inhibit debris-induced inflammation effectively, with no systemic adverse effects.</p>

Human osteoblasts response to different magnitudes of mechanical stimulation in vitro / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the effect of different magnitudes of tensile strain on human osteoblasts differentiation.</p><p><b>METHODS</b>According to the strain amplification mechanism at cellular level and a data calculated by finite element analysis, the cellular level strain of 0.8%, 1.6%, 2.4% and 3.2% was respectively applied to human osteoblasts for 48 h at a frequency of 1 Hz. Alkaline phosphatase activity and the expression of osteoblast-related genes were detected by Semi-Quantitative RT-PCR and densitometric analysis.</p><p><b>RESULTS</b>Alkaline phosphatase activity significantly increased at 0.8% and 1.6%. The level of osteocalcin mRNA increased at 2.4% and 3.2%. Cbfa1/Runx2 gene expression only increased at 3.2%. Comparing to static control, mRNA level of type I collagen increased at every magnitude. The mRNA level decreased at 0.8% and increased at 3.2% when compared to the group with 1.6% elongation.</p><p><b>CONCLUSIONS</b>Higher magnitudes of strain enhance expression of osteocalcin, type I collagen gene and Cbfa1/Runx2 in human osteoblasts, but lost the ability to increase ALP activity which is remained by lower magnitudes of strain. Type I collagen gene expression increases in a strain magnitude dependent manner.</p>

Anterolateral muscle sparing approach total hip arthroplasty: an anatomic and clinical study / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Many kinds of approaches have been used for minimally invasive surgery of total hip arthroplasty (MIS-THA). However, until now when considering the balance of efficacy and associated surgical injury there is no approach widely accepted for MIS-THA. In this study, a modified anterolateral muscle sparing approach was developed to optimize MIS-THA.</p><p><b>METHODS</b>Twenty adult cadaver specimens (40 hips) were used for anatomic research. The distance from anterior origin of the gluteus medius on the iliac crest to the anterior superior iliac spine was measured; the course of the superior gluteal nerve and the distances from the nerve to the regional anatomic landmarks were recorded. Simulated surgeries were performed in three fresh cadaver specimens to evaluate the soft tissues injury around incisions. From October 2004 to June 2006, 57 patients (57 hips) were treated with anterolateral muscle sparing minimally invasive total hip arthroplasty, of which 17 were femoral neck fractures, 9 osteoarthritis, 16 developmental dysplasia of hip (DDH) and 15 avascular necrosis (AVN). All the operations were performed by the same senior surgeon. Operation time, blood loss and drainage volume were recorded and the correlation between the local complications and the native anatomical characteristics was especially noted. All cases were followed for at least 12 months.</p><p><b>RESULTS</b>The distance from the anterior origin of the gluteus medius to anterior superior iliac spine along the iliac crest was (61+/-4) mm (range, 55-68 mm), and the distance from inferior branch of the superior gluteal nerve to the anterior tubercle of the greater trochanter was (74+/-6) mm (range, 60-88 mm). In simulated surgeries, excessive distraction of tissue was found to be the main cause of the anterior border injury of the gluteus medius muscle. Of the 57 patients treated with anterolateral muscle sparing MIS-THA, the average incision length was 9 cm (range 7.5-13 cm). Blood transfusions were performed in 11 patients. During the operations, anterior border injury in deep layers of the gluteus medius was found in 9 patients. Posteromedial perforation of the prosthesis stem on the femoral side was found in 2 patients, which were revised immediately. No positive Trenderlenburg sign was found during the 12 months of follow-up.</p><p><b>CONCLUSIONS</b>The incision of the anterolateral muscle sparing approach should be directed from the anterior tubercle of the greater trochanter toward 6 cm posterior to the anterior superior iliac spine. The proximal part of the incision should be within 6 cm from the anterior tubercle of the greater trochanter, and it is safe to be extended distally. The anterolateral muscle sparing approach is a minimally invasive approach for total hip arthroplasty, through which the surgeon can operate on the acetabulum and femoral sides in a single incision without muscle detachment, and fluoroscopy assistance is not needed. The surgeon should pay more attention to protecting the gluteus medius from injury by distraction before femoral neck cutting and during the preparation of the femoral side.</p>

Hip resurfacing arthroplasty for secondary osteoarthritis after developmental dysplasia of hip / 中华外科杂志

<p><b>OBJECTIVE</b>To study the clinical results of metal on metal hip resurfacing arthroplasty for developmental dysplasia patients.</p><p><b>METHODS</b>From March 2005 to December 2006, 34 cases of developmental dysplasia patients (Crowe I, Crowe II) were attempted to have metal on metal hip resurfacing arthroplasty. There were 29 females (32 hips), 5 males (5 hips). The average age was 45 (26 - 57) years old. Radiographic and clinical evaluations were taken at 6 weeks, 3 months, 1 year and then once a year postoperatively. The average Harris score was 35 (25 - 44). Hip flexion was 101 degrees , abduction 24 degrees , adduction 15 degrees .</p><p><b>RESULTS</b>Three patients were turned to total hip arthroplasty during operations. Thirty-one patients (34 hips) received hip resurfacing surgery. These 31 patients were followed for average 21.4 months (12 - 33 months). The average Harris score was 94 (82 - 100) at the latest follow-up, and there was statistical difference compared with the preoperative score (P < 0.01). Hip flexion increased to 133 degrees , abduction to 48 degrees , adduction to 26 degrees . No radiolucency line was found at both acetabular and femoral sides in all the patients. The average abduction angle of acetabular cup was 43 degrees (40 degrees - 53 degrees ), and the average stem shaft angle was 139 degrees (130 degrees - 145 degrees ).</p><p><b>CONCLUSIONS</b>The short term result is excellent. While the mid to long term results for hip resurfacing arthroplasty in developmental dysplasia patients are still looking forward, and the meticulous surgical technique and strict patient selection are the key of the good results.</p>

Minimally invasive total knee arthroplasty through a quadriceps sparing approach: a comparative study / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate the short term clinical results of minimally invasive total knee arthroplasty (MIS-TKA) through a quadriceps sparing (QS) approach compared with a standard TKA using a medial parapatellar exposure.</p><p><b>METHODS</b>Between March 2005 and March 2006, 26 consecutive unilateral primary MIS-TKA through a QS approach were performed. It was compared that the short term clinical results of this group with an age-matched and sex-match cohort of total knee arthroplasty done with a standard medial parapatellar approach. Length of incision, tourniquet time, blood loss, flexion degree, visual analog scale (VAS) score, Knee Society score, tibiofemoral angle and the ability to do a straight leg raising maneuver were evaluated respectively.</p><p><b>RESULTS</b>The mean follow-up time were 17 months (range 12-23 months). The average length of incision was (9.5+/-1.5) cm in the QS group and (14.0+/-2.3) cm in the standard group (P<0.05). Average tourniquet times were (83+/-16) minutes in the QS group and (55+/-11) minutes for the standard group (P<0.05). Postoperative tibiofemoral angles averaged (5.7+/-1.5) degrees valgus in the QS group knees and (6.0+/-1.4) degrees valgus in the standard group knees (P>0.05). The average VAS scores were significantly lower at the first, the third and the seventh postoperative days in the QS group compared with that of the standard group, and the difference was not significant after 6 weeks between two groups. Mean flexion at one week was greater for the QS group (107+/-12) degrees than that in the standard group (95+/-11) degrees. Improved ROM also was seen 6 and 12 weeks postoperatively in the QS group with significant difference. There were no differences in ROM between the two groups in 12 months. The ability to straight leg raised at one week postoperatively was better in the QS group (23/26, 88%) than that of the standard group (21/33, 64%). At the 6 weeks follow-up, the average knee score was (78+/-15) points in the QS group and (71+/-20) points for the standard group (P<0.05). Deep vein thrombosis were found in 1 case of the QS group and 3 cases for the standard group. One patient in the QS group developed superficial wound necrosis that healed uneventfully. There were no other complications such as deep infection, neurovascular injury and so on.</p><p><b>CONCLUSIONS</b>The MIS-TKA through a QS approach is associated with a more rapid functional recovery and improves range of motion. But higher specifications and more restrictive indications are of importance with the QS technique.</p>

Minimally invasive two-incision total hip arthroplasty: a short-term retrospective report of 27 cases / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Total hip arthroplasty (THA) is widely applied for the treatment of end-stage painful hip arthrosis. Traditional THA needed a long incision and caused significant soft tissue trauma. Patients usually required long recovery time after the operation. In this research we aimed to study the feasibility and clinical outcomes of minimally invasive two-incision THA.</p><p><b>METHODS</b>From February 2004 to March 2005, 27 patients, 12 males and 15 females with a mean age of 71 years (55 - 76), underwent minimally invasive two-incision THA in our department. The patients included 9 cases of osteoarthritis, 10 cases of osteonecrosis, and 8 cases of femoral neck fracture. The operations were done with VerSys cementless prosthesis and minimally invasive instruments from Zimmer China. Operation time, blood loss, length of incision, postoperative hospital stay, and complications were observed.</p><p><b>RESULTS</b>The mean operation time was 90 minutes (80 - 170 min). The mean blood loss was 260 ml (170 - 450 ml) and blood transfusion was carried out in 4 cases of femoral neck fracture (average 400 ml). The average length of the anterior incision was 5.0 cm (4.6 - 6.5 cm) and of the posterior incision 3.7 cm (3.0 - 4.2 cm). All of the patients were ambulant the day after surgery. Nineteen patients were discharged 5 days post-operatively and 8 patients 7 days post-operatively. The patients were followed for 18 months (13 - 25 months). One patient was complicated by a proximal femoral fracture intraoperatively. No other complications, including infections, dislocations, and vascular injuries, occurred. The mean Harris score was 94.5 (92 - 96).</p><p><b>CONCLUSIONS</b>Two-incision THA has the advantage of being muscle sparing and minimally invasive with less blood loss and rapid recovery. However, this technique is time consuming, technically demanding, and requires fluoroscopy.</p>