【Abstract】 Objective To investigate corresponding relation between structure change of the femoral head with“crescent sign” and stress exerted on the avascular necrosis of femoral head, to explore the mechanism of the “crescent sign” formation. Methods From March 1998 to April 2003, the femoral heads of 18 hips in 16 cases having osteonecrosis and “crescent sign” in X-ray film before total hi p arthroplasty, were collected. General and coronal section plane morphology of the femoral heads were observed. The princi ple of effective stress and stress concentration theory were used to explain the phenomena and structure changes in osteonecrosis of the femoral head. Results Cancellous bone existed as a threedimensional,interconnected network of trabeculae rods and plates, with 50%-90% of porosity and 20-30 mmHg bone marrow pressure. According to the definition of porous media, bones especially cancellous bone was a kind of sol id and l iquid two phases porous media. Cross-sectional structure changes in the junction between subchondral plate and cancellous were the place where stress concentrated. The principle of effective stress and stress concentration theory could explain the phenomena and their relationship that occurred in avascular necrosis of the femoral head. Conclusion The “crescent sign” starts in an area of very focal resorption in the subchondral plate laterally and peripherally. The focal resorption in the subchondral plate breaks the continuity of subchondral plate and causes stress concentration in the resorption region. The concentrated stress accumulates in the junction between subchondral plate and unrepaired necrotic cancellous bone brings on the fracture right below the subchondral plate. The focal resorption of the subchondral plate also provides a pathway for the pore water in the unrepaired necrotic bone skeleton to outflow, therefore cause effective stress increase and unrepaired necrotic bone skeleton be compacted by increased effective stress appl ied on unrepaired necrotic cancellous bone skeleton, and results in the volume decrease of unrepaired necrotic cancellous bone and the formation of cavum below the subchondral plate. The cavum shows “crescent sign” in the X-ray film.
fter fracture of femoral neck , the head is often encountered ayascular necrosis. It was not clearwhether the causes of the necrosis was due to injury of the artery or stagnation of venous return orboth. We had observed the hmeodynamics of the blood circulation of both fermoral head of both sides in 27 cases of subcapital fracture by E. C. T. (Emission Computerized Tomography). The resultsshowed that either old, fresh, or heal fractures showed stagnation of venous return. There wasoblite...
Objective To investigate the operative method of trabecular metal rod implant for the treatment of the early adult avascular necrosis of the femoral head (ANFH) and its cl inical efficacy. Methods From March 2005 to January 2007, 28 patients of ANFH were treated by trabecular metal rod implant, including 18 males and 10 females aged 18-56 years old (average 30.6 years old). The ANFH was induced by trauma in 7 cases, steroid in 10 cases, alcohol in 5 cases and unknownreason in 6 cases. There were 22 cases of unilateral ANFH and 6 of bilateral ANFH, involving 18 left hips and 16 right hips. According to Association Research Circulation Osseous (ARCO) international classification of osteonecrosis launched in 1997, 16 cases (16 hips) were classified as stage I, 12 cases (15 hips) as stage I, 1 case (1 hip) as stage III and 2 cases (2 hips) as stage IV. Harris score was 50.3 ± 2.2 preoperatively. The course of disease was 12-24 months (average 16 months). Results All wounds healed by first intention, and no postoperative compl ication occurred. All the cases were followed up for 18-36 months (average 26 months). The pain and functional l imitation of patients were improved significantly. The Harris score was 85.7 ± 2.4 18 months after operation, showing a significant difference when compared with preoperative score (P lt; 0.05). Twenty-three cases were graded as excellent, 3 as good and 2 as fair, with the excellent and good rate of 92.86%. Conclusion Trabecular metal rod implant is an effective method for the treatment of early ANFH and can minimize the occurrence of compl ications, but the follow-up observation of its long-term herapeutic effect is still needed.
Objective To explore the difference between bone marrow edema syndrome (BMES) and avascular necrosis of femoral head (ANFH). Methods Recent original articles about BMES and ANFH were extensively reviewed, and were comprehensively analysed. Results The pathology, pathogenesis, clinical features, treatment selection, and prognosis are different between these two diseases. Conclusion BMES and ANFH are two different diseases. Micro-fracture may be the cause of bone marrow edema.
Objective To compare the cl inical outcomes of the core decompression combined with autologous bone marrow mesenchymal stem cells (BMSCs) transplantation with the isolated core decompression for the treatment of earlyavascular necrosis of the femoral head (ANFH). Methods From May 2006 to October 2008, 8 patients (16 hips) with earlyANFH were treated. There were 7 males and 1 female with an average age of 35.7 years (range, 19-43 years). According to the system of the Association Research Circulation Osseous (ARCO): 4 hips were classified as stage II a, 2 as stage II b, 1 as stage II c, and 1 as stage III a in group A; 2 hips were classified as stage II a, 2 as stage II b, 3 as stage II c, and 1 as stage III a in group B. The average disease course was 1.1 years (range, 4 months to 2 years). The patients were randomly divided into 2 groups according to left or right side: group A, only the core decompression was used; group B, both the core decompression and autologous BMSCs transplantation were used. The Harris score and visual analogue scale (VAS) score were determined, imaging evaluation was carried out by X-rays and MRI pre- and post-operatively. The erythrocyte sedimentation rate, C-reactive protein, l iver function, renal function, and immunoglobul in were detected for safety evaluation. Results All incisions healed by first intention. Eight patients were followed up 12-42 months (23.5 months on average). The cl inical symptoms of pain and claudication were gradually improved. The Harris scores and VAS scores of all patients were increased significantly at 3, 6, and 12 months after operation (P lt; 0.05). There was no significant difference between groups A and B 3 and 6 months after operation (P gt; 0.05), but there was significant difference between groups A and B 12 months after operation (P lt; 0.05). The necrosis area of femoral head in groups A and B were 18.13% ± 2.59% and 13.25% ± 2.12%, respectively, showing significant difference (P lt; 0.05). In group A, femoral head collapsed 12 months after operation in 1 case of stage III. No compl ication of fever, local infectionoccurred. Conclusion The core decompression and the core decompression combined with BMSCs transplantation are both effective for the treatment of early ANFH. The core decompression combined with BMSCs transplantation is better than core decompression in the rel ief of pain and postponing head collapse.
Objective Glucocorticoid is the main cause of non-traumatic avascular necrosis of femoral head. To explore the changes of reactive oxygen species (ROS) in the bone microvascular endothel ial cells treated with glucocorticoid so as to investigate the pathogenesis of steroid-induced avascular necrosis of femoral head. Methods The cancellous bone of femoral head was harvested from voluntary donators undergoing total hip arthroplasty, and then the bone microvascular endothel ial cells were isolated by enzyme digestion. The cells at passage 3 were cocultured with different concentrations of hydrocortisone (0, 0.03, 0.10, 0.30, and 1.00 mg/mL) for 24 hours. MTT assay was used for the inhibitory rate of cell prol iferation, flow cytometry for apoptosis rate, and fluorescence probe for the production of ROS and xanthine oxidase (XOD). Results At 2-3 days primary culture, the cells were spindle and arranged l ike cobbles and they reached confluence after 1 week. The inhibitory rates of cell prol iferation in 0.03, 0.10, 0.30, and 1.00 mg/mL groups were 20.22% ± 2.97%, 22.94% ± 4.52%, 43.98% ± 3.35%, and 78.29% ± 3.85%, respectively; and 2 high-concentration groups (0.30 and 1.00 mg/mL groups) were significantly higher (P lt; 0.05) than 2 low-concentration groups (0.03 and 0.10 mg/mL groups). The apoptosis rates in 0, 0.03, 0.10, 0.30, and 1.00 mg/mL groups were 0.10% ± 0.01%, 0.23% ± 0.02%, 1.83% ± 0.04%, 6.34% ± 0.11%, and 15.33% ± 0.53%, respectively; 2 high-concentration groups (0.30 and 1.00 mg/mL groups) were significantly higher (P lt; 0.05) than 0 mg/mL group. In 0, 0.30, and 1.00 mg/ mL groups, the ROS levels were 57.35 ± 7.11, 120.47 ± 15.68, and 166.15 ± 11.57, respectively, and the XOD levels were 0.017 9 ± 0.000 9, 0.028 3 ± 0.001 7, and 0.067 7 ± 0.004 1, respectively; there were significant differences in the levels of ROS and XOD among 3 groups (P lt; 0.05). Conclusion Increasing of ROS production in bone microvascular endothel ial cells can be induced by high concentration glucocorticoid, and it can result in cell injury
Objective To investigate the effect of glucocorticoid on the expression levels of osteoprotegerin (OPG)/receptor activator of nuclear factor kappa B ligand (RANKL)-matrix metalloproteinases (MMP)/tissue inhibitor of matrix metalloproteinase (TIMP) system in bone tissues of femoral head of rats, and to discuss its interrelated action mechanism in glucocorticoid-induced avascular necrosis of femoral head (ANFH). Methods Forty adult Sprague Dawley rats, weighing 250-300 g, half males and half females, were randomly divided into 4 groups: high dose glucocorticoid group (HD, n=10), medium dose glucocorticoid group (MD, n=10), low dose glucocorticoid group (LD, n=10), and control group (n=10). The rats in HD group, MD group, and LD group were intramuscularly injected with 25.0, 12.5, and 7.0 mg/kg of prednisolone respectively, and the rats in the control group were injected with physiological saline. After 4 weeks intervention, the osteonecrosis of left femoral heads was observed by HE staining, total RNA was extracted from the right femoral head bone tissue and the mRNA expression levels of OPG, RANKL, MMP-2, MMP-9, TIMP-1, and TIMP-2 were detected by RT-PCR. Results After injection of prednisolone, 4 rats of HD group and 1 rat of MD group died of systemic failure caused by the decreased food and weight culminating in cachexia. HE staining showed that the integrity of bone trabecula and osteon was destroyed at different levels, discontinuous bone chips formed, and osteocytes were replaced by granulation tissue in some lacunae in HD, MD, and LD groups; the integrated osteon was observed, the lamellar structure formed concentric circles around the blood vessel and osteocytes were seen in the lacunae in the control group. The necrosis rates of femoral head were 83.3% (5/6), 66.7% (6/9), 30.0% (3/10), and 0 (0/10) in HD, MD, LD, and control groups. The results of RT-PCR showed: the mRNA expression levels of the OPG, TIMP-1, TIMP-2 in HD, MD, and LD groups were lower than those in the control group, showing significant differences (P lt; 0.05) and there was negative correlation with the hormone dosage. The difference in OPG expression was significant between the hormone groups (P lt; 0.05); the differences in the TIMP-1 and TIMP-2 expressions were not significant between the LD group and MD group (P gt; 0.05), but there were significant differences when compared with HD group (P lt; 0.05). The RANKL, MMP-2, and MMP-9 mRNA expression levels in HD, MD, and LD groups were higher than those in the control group and there was a positive correlation with the hormone dosage, showing significant differences when compared MD and HD groups with control group (P lt; 0.05); there was no significant difference in RANKL expression between HD group and MD group (P gt; 0.05), but there was significant difference when compared HD and MD groups with LD group (P gt; 0.05); no significant difference was observed in the MMP-2 and MMP-9 expression between MD group and LD group (P gt; 0.05), but the differences were significant when compared with HD group (P lt; 0.05). Conclusion Glucocorticoid-induced ANFH may be related to the expression levels of OPG/RANKL-MMP/TIMP mRNA regulated by glucocorticoid.
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 investigate the technique and short-term effectiveness of the umbrella-shaped memory alloy femoral head support device (umbrella-shaped support device for short) for the treatment of avascular necrosis of femoral head (ANFH). MethodsThe umbrella-shaped support device was fabricated with Ni-Ti alloy, and its biomechanics characteristics were tested by three-dimensional finite element analysis with pro/mechanica software. Between October 2009 and December 2012, 10 patients (18 hips) with ANFH were treated. There were 7 males (12 hips) and 3 females (6 hips), aged 21-53 years (mean, 40.6 years). The disease duration was 1-5 years (mean, 3.3 years). According to Ficat staged criteria, 10 hips were rated as stage Ⅱ, 6 hips as stage Ⅲ, and 2 hips as stage IV. Microtrauma methods were used to erase the necrotic tissue of the femoral head, and the umbrella-shaped support device, autogenous iliac bone graft, and artificial bone were implanted to support the collapsed femoral head. ResultsThree-dimensional finite element analysis showed that the largest stress of umbrella-shaped support device was 1 500 MPa and the largest displacement was 1.75 mm. Operation was successfully completed in the other 10 patients (17 hips) except 1 failure hip (total hip arthroplasty was performed after 6 months). The average follow-up period was 19.7 months (range, 15-26 months). At last follow-up, the results were excellent in 5 hips, good in 9 hips, fair in 2 hips, and poor in 1 hip; the excellent and good rate was 82.35%. The Ficat stage had no change when compared with preoperative stages. ConclusionThe advantages of the umbrella-shaped support device for the treatment of ANFH are to thoroughly remove the sequestrum, to rebuild blood circulation of the femoral head, to increase the machinery supporting of subchondral bone in weight-bearing area of femoral head, and to decrease the localized stress, and it has good short-term effectiveness, but long-term effectiveness needs further observation.
ObjectiveTo summarize the current researches and progress on experimental animal models of avascular necrosis of the femoral head. MethodsDomestic and international literature concerning experimental animal models of avascular necrosis of the femoral head was reviewed and analyzed. ResultsThe methods to prepare the experimental animal models of avascular necrosis of the femoral head can be mainly concluded as traumatic methods (including surgical, physical, and chemical insult), and non-traumatic methods (including steroid, lipopolysaccharide, steroid combined with lipopolysaccharide, steroid combined with horse serum, etc). Each method has both merits and demerits, yet no ideal methods have been developed. ConclusionThere are many methods to prepare the experimental animal models of avascular necrosis of the femoral head, but proper model should be selected based on the aim of research. The establishment of ideal experimental animal models needs further research in future.