Fuxing Pei

A meta-analysis of the Gamma nail and dynamic hip screw in treating peritrochanteric fractures

The objective of this meta-analysis was to compare the fixation outcome of the Gamma nail and dynamic hip screw (DHS) in treating peritrochanteric fractures. Relevant randomised controlled studies were included, and the search strategy followed the requirements of the Cochrane Library Handbook. Methodological quality was assessed and data were extracted independently. Seven studies involving 1,257 fractures were included which compared the effect of the Gamma nail and DHS. The results showed a higher rate of postoperative femoral shaft fracture with the Gamma nail compared to the DHS [relative risk (RR): 7.27, 95% confidence interval (CI): 2.83–18.70, P < 0.0001] but no statistical differences in wound infection (RR: 1.02, 95% CI: 0.56–1.86), mortality (RR: 1.00, 95% CI: 0.81–1.24), re-operation (RR: 1.64, 95% CI: 0.91–2.95) and walking independently after rehabilitation (RR: 0.89, 95% CI: 0.60–1.33). It seemed that there were no obvious advantages of the Gamma nail over the DHS in treating peritrochanteric fractures.

A systematic review of radiological outcomes of highly cross-linked polyethylene versus conventional polyethylene in total hip arthroplasty.

The purpose of this study was to summarise the best evidence to assess radiological outcomes of highly cross-linked polyethylene compared with conventional polyethylene in total hip arthroplasty. All randomised, controlled clinical trials comparing highly cross-linked polyethylene with conventional polyethylene were sought and then analysed by two independent reviewers using the Cochrane collaboration guidelines. Eight studies in seven articles were identified as eligible for inclusion. Due to the clinical and methodological heterogeneity, data from the studies included could not be pooled. No failures related to highly cross-linked polyethylene were reported. All highly cross-linked polyethylene groups had a significantly lower wear or penetration than conventional polyethylene groups. This preliminary result suggests that highly cross-linked polyethylene has significantly less wear than conventional polyethylene.RésuméLe but de cette étude est de résumer les données indiscutables dans les prothèses totales de hanche concernant l’évaluation du devenir radiologique du polyéthylène hautement réticulé comparé au polyéthylène conventionnel. Tous les essais contrôlés, randomisés comparant le polyéthylène hautement réticulé au polyéthylène conventionnel ont été analysés par deux reviewers indépendants à partir de la base de Cochrane. 8 études dont 7 articles ont été identifiés et inclus dans ce travail. Du fait de l’hétérogénéicité clinique et méthodologique de ces études, toutes les données n’ont pu être regroupées. Aucun échec du polyéthylène hautement réticulé n’a été rapporté. Dans ces études, tous les groupes concernant le polyéthylène hautement réticulé et ont une usure et une pénétration plus basses que le polyéthylène conventionnel ceci de façon significative. Ces données préliminaires permettent de penser que le polyéthylène hautement réticulé a de façon significative moins d’usure que le polyéthylène conventionnel.

Are the results of multiple drilling and alendronate for osteonecrosis of the femoral head better than those of multiple drilling? A pilot study.

OBJECTIVES The treatment of osteonecrosis of the femoral head (ONFH) remains controversial. A recently proposed treatment is multiple drilling core decompression combined with systemic alendronate as a femoral head-preserving procedure for ONFH. However, it is not known whether alendronate enhances the risk of collapse. We wondered whether the combined procedure could delay or prevent progression of ONFH compared to multiple drilling alone. METHODS Patients with early-stage ONFH were randomly assigned to be treated with either multiple drilling combined with alendronate (47 patients, 67 hips) or multiple drilling alone (46 patients, 60 hips). We defined failure as the need for THA or a Harris score less than 70. The minimum follow-up was 48 months for the 77 patients completing the protocol. RESULTS After a minimum 4-year follow-up, 91% (40/44) of patients with Stage II disease and 62% (8/13) of patients with Stage III disease had not required THA in alendronate group, compared to 79% (31/39) of patients with Stage II disease and 46% (6/13) of patients with Stage III disease had not required THA in control group (P=0.12, P=0.047, respectively). Small or medium and central lesions had a better successful rate in both groups. Risk factors did not seem to affect the clinical successful rate of this procedure. CONCLUSIONS Multiple small-diameter drilling core decompression combined with systemic alendronate administration can reduce pain and delay progression of early-stage ONFH. Even in Ficat IIA and III hips, some benefit was obtained from this approach at least delay in the need for THA.

Analyzing the behavior of a porous nano-hydroxyapatite/polyamide 66 (n-HA/PA66) composite for healing of bone defects.

The aim of this study was to analyze the behavior of the porous nano-hydroxyapatite/polyamide 66 (n-HA/PA66) composite grafted for bone defect repair through a series of biological safety experiments, animal experiments, and a more than 5-year long clinical follow-up. The biological safety experiments, carried out in accordance with the Chinese Guo Biao and Tolerancing (GB/T)16886 and GB/T16175, revealed that porous n-HA/PA66 composite had no cytotoxicity, no sensitization effect, no pyrogenic reaction, and that its hemolysis rate was 0.59% (less than 5%). Rabbit models of tibia defects with grafted porous n-HA/PA66 composite were established. After 2 weeks, the experiment showed that osteogenesis was detected in the porous n-HA/PA66 composite; the density of new bone formation was similar to the surrounding host bone at 12 weeks. After 26 weeks, the artificial bone rebuilt to lamellar bone completely. In the clinical study, a retrospective review was carried out for 21 patients who underwent serial radiographic assessment after treatment with porous n-HA/PA66 composite grafts following bone tumor resection. All wounds healed to grade A. No postoperative infections, delayed deep infection, nonspecific inflammation, rejection, or fractures were encountered. At a mean follow-up of 5.3 years, the mean Musculoskeletal Tumor Society’s (MSTS) 93 score was 29.3 points (range: 28–30 points) and mean radiopaque density ratio was 0.77±0.10. The radiologic analysis showed that porous n-HA/PA66 composite had been completely incorporated with the host bone about 1.5 years later. In conclusion, this study indicated that the porous n-HA/PA66 composite had biological safety, and good biocompatibility, osteoinduction, and osseointegration. Thus, the porous n-HA/PA66 composite is an ideal artificial bone substitute and worthy of promotion in the field.

Changes in Cobalt and Chromium Levels After Metal-on-Metal Hip Resurfacing in Young, Active Chinese Patients

Metal-on-metal resurfacing arthroplasty is increasingly being performed in young, active patients. Serum and urine metal ion levels are monitored in these patients to assess the physiologic effects of metal-on-metal wear on them. The aim of our prospective study was to evaluate the serum and urine levels of cobalt (Co) and chromium (Cr) in young (age, ≤50 years), active Chinese patients who had undergone metal-on-metal hybrid resurfacing arthroplasties. Levels were measured preoperatively using atomic absorption spectrometry and then sequentially at 3, 6, 9, 12, and 24 months after surgery. For both serum and urine Co and Cr, there was an initial increase to a peak at 6 months, followed by a gradual decline after 6 months, whereas renal function was normal during the study the 2-year study period. There was no radiographic evidence of component loosening. All implants were functioning well. Further long-term studies are needed to observe clinical outcomes and to determine the physiologic effects of the wearing process.

Hypoxia differentially regulates human nucleus pulposus and annulus fibrosus cell extracellular matrix production in 3D scaffolds

OBJECTIVE We hypothesize that intervertebral disc (IVD) cells from distinct region respond differently to oxygen environment, and that IVD cells from patients with disc degeneration can benefit from hypoxia condition. Therefore, we aimed to determine the transcriptional response and extracellular matrix (ECM) production of nucleus pulposus (NP) and annulus fibrosus (AF) cells to different oxygen tension. METHOD Human NP and AF from degenerated IVD were seeded in 3D scaffolds and subjected to varying oxygen tension (2% and 20%) for 3 weeks. Changes in ECM were evaluated using quantitative real-time reverse transcriptase polymerase chain reaction, histological and immunohistological analyses. RESULTS Hypoxia significantly enhances NP cells phenotype, which resulted in greater production of sulfated glycosaminoglycan (GAG) and collagen type II within the constructs and the cells expressed higher levels of genes encoding NP ECM. A significantly stronger fluorescent signal for hypoxia-inducible factor (HIF-1α) as also found in the NP cells under the hypoxic than normoxic condition. However, there was little effect of hypoxia on the AF cells. CONCLUSIONS The NP and AF cells respond differently to hypoxia condition on the 3D scaffold, and hypoxia could enhance NP phenotype. When used in concert with appropriate scaffold material, human NP cells from degenerated disc could be regenerated for tissue engineering application.

Cementless Total Hip Arthroplasty in Chinese Patients with Osteonecrosis of the Femoral Head

This study was designed to evaluate the midterm (> or = 5 years) clinical and radiographic outcomes of the cementless total hip arthroplasty in 64 Chinese patients (72 hips), which revealed that the mean Harris hip score increased from an average of 44.0 points before operation to 92.4 points at the last follow-up. Excellent results were achieved in 60 hips (83%). No loosening of the components was observed radiographically. No revision of the femoral components was required. Only one focal area of pelvic osteolysis in 1 hip (1%), which requires a revision, and some small focal areas of femoral osteolysis in 12 hips (17%) were observed. The mean linear wear rate was 0.125 mm/y. The survival rate of the acetabular and femoral components for radiographic loosening was 100% (95% confidence interval, 0.93-1.0) and for revision was 98.61% (95% confidence interval, 0.95-1.0). This study indicated that the cementless total hip arthroplasty in patients with osteonecrosis of the femoral head has a satisfactory midterm clinical and radiographic outcomes, but the long-term effect should be further studied.

Midterm Results of Uncemented Acetabular Reconstruction for Posttraumatic Arthritis Secondary to Acetabular Fracture

At an average of 6.3 years after surgery, we evaluated midterm results of uncemented acetabular reconstruction in 31 hips with posttraumatic arthritis that developed after acetabular fracture. Patients were categorized by previous fracture treatments (open-reduction group and conservative-treatment group) and fracture patterns (simple group and complex group). Surgery duration and blood loss were greater in the open-reduction and complex groups than in the conservative-treatment and simple groups (P < .05). The mean Harris Hip Score increased from 49 before surgery to 89 after surgery. Survival with revision or radiographic acetabular loosening as an end point was 100%. Fracture treatments and patterns were associated with increased surgery duration and increased blood loss. Open reduction and internal fixation of a fracture favor anatomical restoration of the hips rotational center.

Effects of an anticoagulant and a lipid-lowering agent on the prevention of steroid-induced osteonecrosis in rabbits

This study was designed to evaluate the effects of the combined treatment with an anti‐coagulant (enoxaparin) agent and a lipid‐lowering agent (lovastatin) on prevention or decrease in the occurrence of steroid‐induced osteonecrosis in rabbits. A total of 112 rabbits, which were injected intramuscularly with 20 mg/kg of methylprednisolone acetate were divided into four groups and treated as follows: one group received enoxaparin combined with lovastatin (EL; n = 30), another received enoxaparin alone (EA; n = 28), another received lovastatin alone (LA; n = 28) and the last received no treatment (non‐prophylactic; NP, n = 26). Haematological examination for serum lipid levels and prothrombin time was carried out and both femora and humeri were examined histopathologically for the presence of osteonecrosis (ON) before injection and at 2, 4, 8 and 12 weeks after the injection. The incidence of ON in the EL group (15%) was significantly lower than that observed in the NP group (68%). The incidence in the EA and LA groups was also significantly lower than that in the NP group (31%, 35%vs. 68%). The fat cell sizes of the bone marrow in both EL (46.49 ± 1.27 μm) and LA (50.8 ± 2.31 μm) groups were lower than in the NP group (59.89 ± 6.33 μm). The prothrombin time was prolonged and plasma lipid levels were reduced in the EL group during the study. Combination treatment with an anti‐coagulant agent and a lipid‐lowering agent can reduce the incidence of steroid‐induced ON in rabbits. Future evaluation in clinical practice is necessary.

Both systemic and local lipopolysaccharide (LPS) burden are associated with knee OA severity and inflammation.

OBJECTIVE The microbiome is recognized as a new frontier in medicine with connections to a variety of diseases. We aimed to evaluate the association of lipopolysaccharide (LPS), a key pro-inflammatory product of the microbiome, with severity of inflammation, symptoms and radiographic abnormalities of knee osteoarthritis (OA). DESIGN LPS was measured using a recombinant Factor C (rFC) assay, carefully optimized for systemic and synovial fluid (SF) analyses. LPS binding protein (LBP) was tested in both serum and SF of 25 patients (31 knees) from the Etarfolatide cohort for association with OA phenotypic outcomes. Models were adjusted for age, gender and body mass index. RESULTS Based on LPS spike-and-recovery, both serum and SF dilutions of 0.1% were required to achieve recovery rates of at least 75% in all test specimens. Low coefficients of variation (CVs) (<10%) were achieved with both serum and SF dilutions <0.2%. Serum LPS and LBP were associated with the abundance of activated macrophages in the knee joint capsule and synovium. SF LPS and LBP were associated with the abundance of activated macrophages in the synovium. Serum LPS, LBP and SF LPS were associated with knee osteophyte severity. SF LPS was positively associated with knee joint space narrowing (JSN) severity and total WOMAC score. SF LBP was positively associated with self-reported knee pain score. CONCLUSION These data strongly support a role for LPS in the pathogenesis and severity of structural abnormalities and symptoms of knee OA.