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OBJECTIVE@#To explore the tensile mechanics and anatomical characteristics of the posterior hip capsule, and provide biomechanical and anatomical evidence for capsule repair in total hip replacement.@*METHODS@#Six bone-capsule-bone specimens were obtained from posterior hip joint of fresh frozen cadavers. The maximum strain, load, elastic modulus and load strain curves of the capsule ligament complex specimens were recorded by Instron Universal Material Testing Machine. Twelve cadaveric hip specimens were dissected to the capsule. The tensile strain of normal capsule and conventionally reconstructed capsule at 90 degrees of hip flexion were documented. The suture area of the posterior capsule was divided into nine sections, and the thicknessof different sections was measured and compared. Posterior capsule of the cadavers was repaired in conventionally way and anatomical way separately and simulated rehabilitation was conducted. The effect of rehabilitation on the repaired capsule was observed.@*RESULTS@#The load-strain curve of capsule ligament complex conforms to rheological and viscoelastic characteristics. The maximum tensile strain of the complex was (39.21±5.23)%, the maximum load was (142.06± 34.15) N, the tensile strength was (1.65±0.38) MPa, and the elastic modulus is (14.23±5.62) MPa. At 90 ° hip flexion, the tensile strain of repaired capsule was higher than that of normal capsule, and the difference was statistically significant (< 0.05). Tensile strain of conventionally reconstructed capsule is:upper part (37.0±4.9)%, middle part ( 53.3±1.1)%, lower part (68.3±6.2)%, tensile strain of normal capsule is:upper part (17.0±2.6)%, middle part (24.1±1.4)%, lower part (26.0± 4.3)% . The thickness of the posterior joint capsulein different sections is statistically significant (<0.05), and capsule at 0.5cm proximal to the femoral insertion is suitable for suture. There the average thickness of capsule is:upper part (3.48 ± 0.11) mm, middle part (2.36 ± 0.09) mm, lower part (1. 59±0.24) mm. The posterior inferior joint capsule is thinnest at (1.42± 0.02) cm proximal to the femoral insertion, and sutures should be avoided here. After simulating rehabilitation, avulsion occurred in the lower part of the posterior capsule repaired conventionally (10/12), and the anatomically repaired capsule remained intact.@*CONCLUSION@#The lower part of conventionally repaired capsule is overstretched and tends to fail. Anatomically repaired capsule conforms to tensile mechanics and is helpful to reduce the failure rate of repair.
Subject(s)
Humans , Arthroplasty, Replacement, Hip , Biomechanical Phenomena , Femur , Hip Joint , General Surgery , Joint Capsule , General Surgery , Tensile StrengthABSTRACT
The distal tibiofibular syndesmosis is a critical structure in maintaining the ankle stability. Syndesmotic injuries are usually associated with ankle fractures and high fibula fractures. Non-isolated and partially isolated syndesmotic injuries are involved in unstable injuries, which need to operative treatment. Partially isolated syndesmotic injuries belong to stable injuries, which should be treated with non-operative management. It is becoming clear that early fixation and stabilization for unstable injuries are probably better than non-treatment or delayed treatment. It still remains without consensus of accurately defining stable from unstable injuries and sufficiently differentiating between acute and chronic injuries. Because of stability, fixation type, and duration, the clinical efficacy is different. Screw fixation is a gold standard treatment of syndesmotic injury. However, it remains controversial that whether removal of the syndesmotic screw is required and effect of the level of syndesmotic screw insertion, limited micro-movement is one of disadvantages of screw fixation. Micro-movement of the distal tibiofibular syndesmosis has been paid more and more attention. Dynamic fixation is a viable alternative to the static fixation device, with lower re-operation rates and less complications, which has obtained a great short-term clinical efficacy. However, further long-term studies should be carried out to confirm this clinical efficacy. Optimized treatment strategies considering stability of syndesmotic injury, duration, and fixation type can help to improve clinical efficacy.
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ObjectiveTo prepare a novel etimicin-encapsuled chitosan/hydroxyapatite nano-scaffolds and offer assistances for bone defect or osteomylitis.MethodsDrug-carried chitosan nanoparticles which was prepared by ionotropic gelation were combined with nano-hydroxyapatite.The mixture were shaped in molds and then prepared into porous scaffolds by freeze-dry.The surface of one scaffold was scanned.The grinded,particles of the scaffold were detected by field emission scanning electron microscope; X-ray diffraction was used to analyze components of the scaffold and total porosity.Staphylococcus aureus was choosed as the experimental bacteria,we studied lasting antibacterial property of drug-carried bone scaffold by antibacterial experiments,long-term drug releasing experiments and accumulation drug releasing experiments.Bone mesenchymal stem cells were used to detect the histocompatibility and inductivity of etimicin-carried scaffold.ResultsFreeze-dried porous scaffold has a surface with proper pore distribution (total porosity 70.68％) and the grinded scaffold has a globular and coliformed microstructure known after scanned by electron microscope.The drug-carried scaffold has a typical wave of hydroxyapatite under X-ray diffraction.The lasting antibacterial property study indicated that the drug-carried bone scaffold had maintained an inhibition zone for more than 7 days.The long-term drug releasing experiments and accumulation drug releasing experiments show that the fictional drug-carried bone scaffold released above the bacteriostasis concentration after one week and the accumulative amount within the safety scale.The scaffold had not an inhibitory effect on bone mesenchymal stem cells.ConclusionThe etimicin-encapsuled chitosar/ hydroxyapatite nano-scaffolds has similar microstructure and components of bone tissue.It is promising in bone tissue engineering applications because of its slow-release,antibacterial properties and satisfactory histocompatibility.
ABSTRACT
The purpose of this study was to compare the efficacy of CEP plus G-CSF and CVP plus G-CSF regimens in the mobilization and collection of peripheral blood hematopoietic stem cells (PBHSC), and in the hematopoietic recovery. 57 patients with non-Hodgkin's lymphoma (NHL) underwent autologous PBHSC transplantation were analyzed retrospectively. The PBHSC were mobilized and collected by using CEP plus G-CSF and CVP plus G-CSF respectively, and were retransfused into these NHL patients after preconditioning, then the mobilization efficacy, adverse reactions and hematopoietic recovery were analyzed. The results showed that the WBC count decreased to ≤ 1.0 × 10(9)/L, platelet amount dropped to ≤ 40 × 10(9)/L during peripheral blood stem cell mobilization of all patients, which indicated successful collection of PBHSC. The mean value of (4.38 ± 3.40) × 10(8)/kg mononuclear cells (MNC) containing (2.79 ± 2.53) × 10(6)/kg CD34(+) cells were collected in CEP plus G-CSF group, while the mean value of (3.31 ± 1.23) × 10(8)/kg MNC containing (2.02 ± 0.87) × 10(6)/kg CD34(+) cells were collected in CVP plus G-CSF group. The efficacy of mobilization in CEP plus G-CSF group was significantly higher than that in CVP plus G-CSF group (p < 0.05). After preconditioning, bone marrow was suppressed in all patients. The average time of WBC count recovery to ≥ 1.0 × 10(9)/L was 11.4 days in CEP plus G-CSF group and 12.3 days in CVP plus G-CSF group; the average time of platelet amount recovery to ≥ 50 × 10(9)/L was 18.6 days in CEP plus G-CSF group and 19.3 days in CVP plus G-CSF group. The statistical analysis showed no significant difference in the average time of hematopoietic recovery between 2 groups. It is concluded that autologous PBHSC transplantation shows significant effect for treatment of patients with NHL. Either modified CEP or CVP plus G-CSF regimen is safe and effective in PBHSC mobilization. The CEP plus G-CSF regimen is better than CVP plus G-CSF regimen.