【Abstract】 Objective To investigate the spectrum of CT and MR imaging and surgical operation findings in il iopsoasbursitis in patients with avascular necrosis of femoral head so as to enhance the diagnostic abil ity. Methods A total of 1 415 patients with avascular necrosis of the femoral head were analyzed retrospectively; of them, 15 patients were compl icated by il iopsoas bursitis surgically or aspiration of synovial fluid between May 2005 and May 2007. Fifteen cases were all necrosis of the bilateral femoral head and 17 hips were combined with il iopsoas bursitis. There were 14 males and 1 female, aging 29-58 years. The course of disease was 1 month to 3 years. All 15 patients had l imitation of abil ity of the hips and the “4” type sign was positive. The Harris score of hip’s function was 54-78 (mean 62.7). Five patients of them can be touched a palpable cystic mass and tenderness in the inguinal area, and 3 of them associated with femoral neuropathy and 2 patients presented sl ight atrophy of the thigh muscle in suffering side. All these cases were taken X-ray films of positive and frog-leg lateral position, hel ical CTscan with 5 mm thinness, and MRI was performed in 6 patients with T1WI, T2WI, T2WI and fat-saturated inversion recovery sequence. Results The radiographs were the primary basis evidences for diagnosis and degrees of the avascular necrosis of femoral head. According to the standards of Association Research Circulation Osseuse, there were 2 hips at stage II(II C 2), 6 hips at stage Ⅲ ( Ⅲ B 1, Ⅲ C 5 ) and 9 hips at stage IV. The X-ray films showed the bulging of the fat pad and soft tissue swell ing in 6 patients. CT analysis disclosed that the enlarged il iopsoas bursae appeared as hypodense, well-defined, thin-walled (lt; 2 mm) cystic structures. The content of the examined bursae was homogeneous with a CT density of ranging from 12.7 to 41.2 Hu, showing fluid collection. They were round or oval in shape medial to the il iopsoas, exhibiting inverted water-drop cystic shadow just inferior to the femoral head. Sl ight contrast enhancement of the bursal wall was seen after contrast agent administration in 3 cases. MRI demonstrated that the il iopsoas bursitis presented as low signal on T1WI and water-l ike highsignal on T2WI and markedly higher signal on STIR in 6 cases. The demonstration of the extent, size, mass effects and its relation and subsequent affection to surrounding anatomical structures were clearly shown by MRI, and by the communications between the il iopsoas bursa and the adjacent hip joint. Conclusion In the diagnosis of avascular necrosis of femoral head with imaging approaches, much attention should be paid to the abnormal ities around the articular capsule to early identify il iopsoas bursitis for further management.
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.
【Abstract】 Objective To establ ish a stable animal model for glucocorticoid-induced avascular necrosis of femoral head in rabbits. Methods Thirty-six adult New Zealand rabbits were randomly divided into four groups:ten were injected twice with l i popolysaccharide (group A), ten were treated with a combination of l i popolysaccharideand methylprednisolone (group B), ten were injected three times with methylprednisolone (group C), and six wereinjected normal sal ine as a control (group D). MR imaging was performed in the rabbits before the first injection ofl i popolysaccharide or methylprednisolone, and at 2, 4, and 6 weeks after the last injection of l i popolysaccharide ormethylprednisolone. Histopathological changes in the femoral heads were observed by l ight microscope and transmission electron microscope at the end of six weeks after the injection. Vascular infusion with Chinese ink was made to evaluate the morphological changes of blood vessels in the femoral head. The percentage of trabecular bone area and empty lacunae and microvascular density were measured. According to the histological and MR imaging appearance of the femoral heads in all groups, the incidence of osteonecrosis of every group was calculated. Results Listlessness, blepharal hyperemia,less activity and reduced diet were found in the rabbits of groups A and B after injected with l ipopolysaccharide. At 3 weeks after the final injection, the body weight of groups B and C was decreased. At 4 weeks after the final injection, the body weight of groups A and D was increased. No abnormal signal could be detected on MR images in rabbits of all groupsbefore injection and at 2 weeks after the injection. At 4 weeks and 6 weeks after the last injection, irregular low signal on T1-weighted images and irregular low or high signal on T2-weighted images could be detected on MR images in rabbits of groups B and C, no abnormal signal could be detected on MR images in rabbits of groups A and D. At 6 weeks after the last injection,the trabecular bone of group B became thin and sparse, some were broken. The percentages of empty lacunae were 11.8% ± 4.7%, 34.4% ± 6.2%, 20.0% ± 4.7% and 9.3% ± 4.6%; the percentages of trabecular bone area were 59.2% ± 6.8%, 40.1% ± 6.0%, 51.5% ± 5.6% and 63.2% ± 8.3%; and the microvascular densities were 14.3% ± 2.7%, 4.5% ± 2.1%, 10.2% ± 3.1% and 15.4% ± 4.1% in groups A, B, C and D respectively. There were statistically significant differences between group B and groups A, C, D (P lt;0.01). The fatty tamponade accumulated in the medullary cavity and intramedullary vascular sinusoids were pressed by the l ipocytes and became narrow. Limposomes were found in osteocytes and vascular endothel ia of group B and group C. Osteocytes of group B crimpled and pyknosis or karyolysis of chromatin were observed in these osteocytes, nuclearmembrane of the osteocytes was discontinous. Vascular endothel ia became swollen and the cell junctions widened or were destroyed in groups A and B. The incidence of osteonecrosis in group B (88.9%) was higher than that in group C (22.2%, P lt; 0.05). There was no osteonecrosis occurred in groups A and D . Conclusion Methylprednisolone combined with l ipopolysaccharide can induce typical rabbit model for early avascular necrosis of femoral head.
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.
【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.
【Abstract】 Objective To introduce a new method using calcium phosphate cement/Danshen drug del ivery systemfor avascular necrosis of femoral head and to evaluate its cl inical outcome. Methods From May 2000 to June 2005, 48 patients (54 hips) with avascular necrosis of femoral head were treated with calcium phosphate cement/Danshen drug del ivery system implantation in the involved femoral head. There were 32 males(36 hips) and 16 females(18 hips) with an average age of 38.7 years (26-62 years). Twenty-one cases had the history of drinking or smoking, 15 cases had the history of receiving hormonotherapy and 2 had the history of injury in hip joint. The disease course was 2-32 months. According to standard of Association Research Circulation Osseous (ARCO) staging, 9 hips were classified as stage I, 31 as stage II and 14 as stage III. The operation consisted of removal of necrotic bone under weight-loading cartilage and the implantation of calcium phosphate cement/Danshen drug del ivery system, all mani pulations were done through a bone tunnel in trochanter. The function of hi p joint were evaluated and X-ray films were taken pre- and post-operatively. Results No phlebothrombosis of leg and foreign body action occurred in all cases, and incision healed by first intention. The postoperative follow-up averaged 42.5 months, ranging from 22 to 73 months. According to the evaluation criterion of Dandong 1995 for adult avascular necrosis of femoral head, the results were excellent in 33 hi ps, good in 17, fair in 3 and poor in 1, the excellent and good rate was92.6 %. Conclusion This method is relatively simple with less invasion, it not only improves the microcirculation of femoral head by local appl ication of traditional Chinese medicine, but also provide mechanic buttress in the weight-loaded area, which is beneficial to repair and reconstruction of femoral head. It may be a choice of minimally invasion surgery for femoral head necrosis.
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.
Objective To study the expression changes of vascular endothel ial growth factor (VEGF), basic fibroblast growth factor (bFGF), and bone morphogenetic protein 2 (BMP-2) in femoral neck fracture, traumatic, and non-traumatic avascular necrosis of femoral head (ANFH), and to study the relationshi p between the expressions of VEGF, bFGF, BMP-2mRNA and bone mass so as to explore the pathogenesis of ANFH and provide the exprimental basis for individual treatment of ANFH. Methods Femoral head specimens were obtained from 59 donors undergoing total hip replacement, including 22 cases of traumatic ANFH (group A, 13 cases of Ficat stage III and 9 cases of Ficat stage IV), 19 cases of non-traumatic ANFH (group B, 11 cases of Ficat stage III and 8 cases of Ficat stage IV; 10 cases of steroid-induced ANFH, 7 cases of alcohol ic ANFH, and 2 cases of unexplained ANFH), and 18 cases of fresh femoral neck fracture (group C). There was no significant difference in the general data among 3 groups (P gt; 0.05). The bone mineral density (BMD) at weight-bearing area of the femoral head was measured with dual energy X-ray absorptiometry. The pathological changes were observed by using optical microscope and scanning electron microscope. The percentage of empty bone lacuna and the percentage of trabecular bone area were calculated. The expressions of VEGF, bFGF, and BMP-2 mRNA in femoral head were detected by use of in-situ hybridization technique. Results The BMD in groups A and B were significantly lower than that in group C (P lt; 0.05), and there was significant difference between group A and group B (P lt; 0.05). In the necrosis area of groups A and B, the bone trabecula was rarefactive and not of integrity, with a great number of empty bone lacuna. In healthy area, more fiber hyperplasia was observed in group A, the prol iferated and hypertrophic fat cells in the medullary cavity in group B. Scanning electron microscope showed that many osteocytes underwent fatty degeneration and necrosis, and that the prol iferation of fat cells in bone matrix was observed in groups A and B. While in group C, the femoral head had intact articular cartilage and intact bone trabeculae, and osteocytes were clearly seen. The percentage of empty bone lacuna was significantly higher (P lt; 0.05) and the percentage of trabecular bone area was significantly lower (P lt; 0.05) in groups A and B than group C; and there was significant difference in the percentage of empty bone lacuna between groups A and B (P lt; 0.05). The expressions of VEGF, bFGF, and BMP-2 mRNAwere significantly lower in groups A and B than group C (P lt; 0.05), and the expressions of BMP-2 and bFGF mRNA in group A were significantly higher than those in group B (P lt; 0.05). There were positive l inear correlation between the expressions of VEGF mRNA, bFGF mRNA, BMP-2 mRNA and the BMD and percentage of trabecular bone area, respectively. While there were significantly negative correlation between the expressions of VEGF mRNA, bFGF mRNA, BMP-2 mRNA and percentage of empty bone lacuna. Conclusion The repair capacity of local femoral head in traumatic ANFH is ber than that in non-traumatic ANFH. The expressions of VEGF mRNA, bFGF mRNA, and BMP-2 mRNA decl ine in traumatic and nontraumatic ANFH.
Objective To compare effectiveness between sequestrum clearance and impacting bone graft and rotational osteotomy on the base of femoral neck via surgical hip dislocation approach for avascular necrosis of femoral head (ANFH) at Association Research Circulation Osseous (ARCO ) stage Ⅲ. Methods A clinical data of 24 patients (27 hips) with ANFH at ARCO stage Ⅲ, who met the inclusion criteria between June 2012 and November 2017, was retrospectively analysed. Of all patients, 12 patients (14 hips) were treated with sequestrum clearance and impacting bone graft via surgical hip dislocation approach (group A); and 12 patients (13 hips) were treated with rotational osteotomy on the base of femoral neck via surgical hip dislocation approach (group B). There was no significant difference in gender, age, disease duration, and affected side, type, and stage of the ANFH between 2 groups (P>0.05). The operation time of each hip and hospitalization stays of each patient in 2 groups were recorded and compared. Imaging examination was performed to observe the blood supply around femoral head, healing of the osteotomy, and the femoral head collapsed. The function of the hip was evaluated by Harris score. Results There was no significant difference in operation time and hospitalization stays (t=–0.262, P=0.797; t=–0.918, P=0.411). All patients were followed up, the follow-up time of group A was 12-28 months (mean, 19.7 months), and the follow-up time of group B was 14-24 months (mean, 17.8 months). The Harris score in groups A and B increased significantly at 6 months and 12 months after operation when compared with preoperative ones (P<0.05). There was no significant difference between 2 groups at 6 months and 12 months (P>0.05). At 12 months after operation, according to the Harris scoring, there were 3 hips of excellent, 7 hips of good, and 4 hips of poor, with the excellent and good rate of 71.4% in group A; there were 5 hips of excellent, 7 hips of good, and 1 hip of poor, with the excellent and good rate of 92.3% in group B. Digital substraction angiography was performed at 1 week after operation and indicated that the blood supply around the femoral head was not destroyed during the operation. Imaging examination after operation showed that the osteotomy of the greater trochanter all healed in 2 groups and the osteotomy of the femoral neck healed in group B. Hip collapse occurred in 2 patients (2 hips) of group A at 12 months after operation. No hip collapse occurred in group B. Conclusion The rotational osteotomy on the base of femoral neck via surgical hip dislocation approach is superior to sequestrum clearance and impacting bone graft in delaying the collapse and improving the hip function for patients with ANFH at ARCO stage Ⅲ.
Objective To review the relationshi p between heritable hypercoagulable state (HHCS) and avascular necrosis of femoral head (ANFH). Methods The latest original articles about the relationshi p between HHCS and ANFH were extensively reviewed. Results Several genetic mutations which could cause HHCS, such as thrombophilic factor V G1691A gene, thrombophilic factor II G20210A gene, 5, 10-methylenetetrahydrofolate reductase C677T gene, plasminogen activator inhibitor 1 4G/5G, and tissue factor pathway inhibitor gene, may be genetic risks of ANFH. Conclusion HHCS may be a genetic cause of ANFH. Further studies are needed to confirm the relationship between HHCS and Chinese ANFH.