As a common disease in orthopedics, osteonecrosis of the femoral head (ONFH) frequently occurs among young and middle-aged people. Hip joint preserving surgery has attracted more and more attention due to the fact that artificial joint prosthesis has a certain useful life and the rate of hip joint revision is high and the higher risk of many complications. There are a large number of operative methods for preserving hip joint in clinical practice without definitive effectiveness. How to choose appropriate surgical methods at the right time is also a continuous understanding. The pathological process of necrosis of the femur helps to choose the choice of the femoral head necrosis for the treatment of hip operation. Core decompression and impaction bone grafting with simple operative methods can relieve internal pressure of femoral head and pain symptoms, but they cannot remove necrotic bone completely. Hence, they are only used for ONFH in the early stage. Vascularized bone transplantation can fill defects of the former, as it can not only completely remove necrotic bone, but also provide bone graft with nourishing vessels for femoral head, being beneficial to reconstruct the bone structure of femoral head. Subsequently, the application of tantalum rod can provide mechanical support for femoral head to prevent the collapse of femoral head. Hip joint preserving surgery, in recent years, has been performed increasingly, and has obtained improvement in clinical effects. The multiple combination of a variety of its operative methods provides more effective treatments for ONFH. It is an essential notion that hip joint preserving surgery, however with any operative method, should as far as possible select a surgical plan with little trauma, simple methods, and little injury of hip joint bone structure based on ensuring the effectiveness.
Objective To compare heterotopic ossification between femoral head reconstruction and total hip arthroplasty(THA) in patients with ischemic necrosis of femoral head(INFH). Methods Between June 1994 and December 2004, the femoral heads were repaired in 1 005 patients with INFH,the total hip was replaced in 485 patients with INFH. The rate of heterotopic ossification was observed in 74 (Ficat Ⅲ to Ⅳ stages) of 1 005 patients and 80 of 485 patients given THA to compared the results of the two methods. Results These patients were followed up 2 to 10 years(6.5 years on average). The rates of heterotopic ossification were 5.4%(4/74) and 22.5%(18/80), respectively. There was statistically significant difference between two operative methods (Plt;0.01). Conclusion The rate of heterotopic ossification of femoral head reconstruction is lower than that of THA, so femoral head reconstruction is a better operative method for young patients and THA is suitable for old patients.
ObjectiveTo summarize the characteristics and biomechanical research progress of common internal fixation for femoral neck fractures in recent years, so as to provide reference to clinical treatment of femoral neck fracture. Methods The domestic and foreign relevant literature on biomechanics of internal fixation of femoral neck fracture in recent years was reviewed, and the biomechanical research progress was summarized. Results Among the internal fixations currently used in the treatment of femoral neck fractures, three cannulated screws can provide sliding compression at the end of the fracture, but the shear resistance is weak, and the risk of long-term internal fixation failure is high; dynamic hip screw and proximal femoral locking plate have excellent angle stability and overall strength; medial buttress plate can transform vertical shear force into compressive stress to promote fracture healing and produce a certain anti-rotation effect; femoral neck system can support the fracture in multi-axial direction, with excellent anti-rotation and anti-shortening properties; and cephalomedullary nails have high overall strength and failure load. Different internal fixations have their own indications due to differences in structure and biomechanics. ConclusionAt present, there is no detailed standard guidance of internal fixation selection. Clinically, the appropriate treatment should be selected according to the fracture types of patients.
Znic (Zn) alloys with good cytocompatibility and suitable degradation rate have been a kind of biodegradable metal with great potential for clinical applications. This paper summarizes the biological role of degradable Zn alloy as bone implant materials, discusses the mechanical properties of different Zn alloys and their advantages and disadvantages as bone implant materials, and analyzes the influence of different processing strategies (such as alloying and additive manufacturing) on the mechanical properties of Zn alloys. This paper provides systematic design approaches for biodegradable Zn alloys as bone implant materials in terms of the material selection, product processing, structural topology optimization, and assesses their application prospects with a view to better serve the clinic.
Objective To summarize the characteristics and biomechanical research progress of common acetabular reconstruction techniques in patients with Crowe type Ⅱ and Ⅲ developmental dysplasia of the hip (DDH) undergoing total hip arthroplasty (THA), and provide references for selecting appropriate acetabular reconstruction techniques for clinical treatment of Crowe type Ⅱ and Ⅲ DDH. Methods The domestic and foreign relevant literature on biomechanics of acetabular reconstruction with Crowe type Ⅱ and Ⅲ DDH was reviewed, and the research progress was summarized.Results At present, there are many acetabular reconstruction techniques in Crowe type Ⅱ and Ⅲ DDH patients undergoing THA, with their own characteristics due to structural and biomechanical differences. The acetabular roof reconstruction technique enables the acetabular cup prosthesis to obtain satisfactory initial stability, increases the acetabular bone reserve, and provides a bone mass basis for the possible secondary revision. The medial protrusio technique (MPT) reduces the stress in the weight-bearing area of the hip joint and the wear of the prosthesis, and increases the service life of the prosthesis. Small acetabulum cup technique enables shallow small acetabulum to match suitable acetabulum cup to obtain ideal cup coverage, but small acetabulum cup also increases the stress per unit area of acetabulum cup, which is not conducive to the long-term effectiveness. The rotation center up-shifting technique increases the initial stability of the cup. Conclusion Currently, there is no detailed standard guidance for the selection of acetabular reconstruction in THA with Crowe type Ⅱ and Ⅲ DDH, and the appropriate acetabular reconstruction technique should be selected according to the different types of DDH.
Objective To review the research progress in the construction strategy and application of bone/cartilage immunomodulating hydrogels. Methods The literature related to bone/cartilage immunomodulating hydrogels at home and abroad in recent years was reviewed and summarized from the immune response mechanism of different immune cells, the construction strategy of immunomodulating hydrogels, and their practical applications. Results According to the immune response mechanism of different immune cells, the biological materials with immunoregulatory effect is designed, which can regulate the immune response of the body and thus promote the regeneration of bone/cartilage tissue. Immunomodulating hydrogels have good biocompatibility, adjustability, and multifunctionality. By regulating the physical and chemical properties of hydrogel and loading factors or cells, the immune system of the body can be purposively regulated, thus forming an immune microenvironment conducive to osteochondral regeneration. ConclusionImmunomodulating hydrogels can promote osteochondral repair by affecting the immunomodulation process of host organs or cells. It has shown a wide application prospect in the repair of osteochondral defects. However, more data support from basic and clinical experiments is needed for this material to further advance its clinical translation process.
Objective To explore the effectiveness of pedicled il iac bone graft transposition for treatment of avascular necrosis of femoral head (ANFH) after femoral neck fracture. Methods Between June 2002 and December 2006, 22 cases (22 hips, 16 left hips and 6 right hips) of ANFH after femoral neck fracture were treated with il iac bone graft pedicled with ascending branch of the lateral femoral circumflex vessels. There were 18 males and 4 females with an age range from 28 to 48 years (mean, 37.5 years). The time from injury to internal fixation was 2-31 days, and all fractures healed within 12 months after internal fixation. The ANFH was diagnosed at 15-40 months (mean, 22 months) after internal fixation. The ANFH duration was 3-11 months (mean, 8 months). According to Association Research Circulation Osseous (ARCO) staging system, 2 hips were classified as stage IIa, 3 hips as stage IIb, 3 hips as stage IIc, 3 hips as stage IIIa, 7 hips as stage IIIb, and 4 hips as stage IIIc. The preoperative Harris hip score (HHS) was 64.10 ± 5.95. Results All incisions healed by first intention and the patients had no compl ication of lung embol ism, sciatic nerve injury, lower l imb deep venous thrombosis, and numbness and pain of donor site. All patients were followed up 2.5 to 6.3 years (mean, 4.8 years). The fracture heal ing time was 8-12 months, and no femoral neck fracture recurred. The HHS was 90.20 ± 5.35 at last follow-up, showing significant difference when compared with the preoperative value (t= —18.447, P=0.000). The hi p function were excellent in 11 hi ps, good in 10 hips, fair in 1 hip, and the excellent and good rate was 95.5%. Four hips were radiographically progressed in ARCO staging, 18 hips remained stable with a stable rate of 81.8%. Conclusion Pedicled il iac bone graft transposition is an ideal option for treatment of ANFH after internal fixation of femoral neck fracture for the advantages of femoral head revascularization, sufficient cancellous bone supply, and relatively simple procedure.
ObjectiveTo evaluate the effect of a novel micro-arc oxidation (MAO) coated magnesium-zinc-calcium (Mg-Zn-Ca) alloy scaffold/autologous bone particles to repair critical size bone defect (CSD) in rabbit and explore the novel scaffold in vivo corrosion resistance and biocompatibility.MethodsSeventy-two New Zealand white rabbits were randomly divided into 3 groups (n=24), group A was uncoated Mg-Zn-Ca alloy scaffold group, group B was 10 μm MAO coated Mg-Zn-Ca alloy scaffold group, and group C was control group with only autologous bone graft. The animals were operated to obtain bilateral ulnar CSD (15 mm in length) models. The bone fragment was removed and minced into small particles and were filled into the scaffolds of groups A and B. Then, the scaffolds or autologous bone particles were replanted into the defects. The animals were sacrificed at 2, 4, 8, and 12 weeks after surgery (6 rabbits each group). The local subcutaneous pneumatosis was observed and recorded. The ulna defect healing was evaluated by X-ray image and Van Gieson staining. The X-ray images were assessed and scored by Lane-Sandhu criteria. The percentage of the lost volume of the scaffold (ΔV) and corrosion rate (CR) were calculated by the Micro-CT. The Mg2+ and Ca2+ concentrations were monitored during experiment and the rabbit liver, brain, kidney, and spleen were obtained to process HE staining at 12 weeks after surgery.ResultsThe local subcutaneous pneumatosis in group B was less than that in group A at 2, 4, and 8 weeks after surgery, showing significant differences between 2 groups at 2 and 4 weeks after surgery (P<0.05); and the local subcutaneous pneumatosis was significantly higher in group B than that in group A at 12 weeks after surgery (P<0.05). The X-ray result showed that the score of group C was significantly higher than those of groups A and B at 4 and 8 weeks after surgery (P<0.05), and the score of group B was significantly higher than that of group A at 8 weeks (P<0.05). At 12 weeks after surgery, the scores of groups B and C were significantly higher than that of group A (P<0.05). Meanwhile, the renew bone moulding of group B was better than that in group A at 12 weeks after surgery. Micro-CT showed that ΔV and CR in group B were significantly lower than those in group A (P<0.05). Van Gieson staining showed that group B had better biocompatibility and osteanagenesis than group A. The Mg2+ and Ca2+ concentrations in serum showed no significant difference between groups during experiments (P>0.05). And there was no obvious pathological changes in the liver, brain, kidney, and spleen of the 3 groups with HE staining at 12 weeks.ConclusionThe MAO coated Mg-Zn-Ca alloy scaffold/autologous bone particles could be used to repair CSD effectively. At the same time, 10 μm MAO coating can effectively improve the osteanagenesis, corrosion resistance, and biocompatibility of Mg-Zn-Ca alloy scaffold.