MicroRNA-145 Mediates Steroid-Induced Necrosis of the Femoral Head by Targeting the OPG/RANK/RANKL Signaling Pathway

Objective

To investigate the role of microRNA-145 (miR-145) in steroid-induced necrosis of the femoral head (SINFH) by evaluating its effects on the OPG/RANK/RANKL signaling pathway.

Methods

A rat model of SINFH was constructed via injection of the lentiviral vector pLV-shRNA-miR-145. Pathological observation was performed via tartrate-resistant acid phosphatase (TRAP) staining, and serum OPG levels were detected by ELISA. The mRNA expression levels of miR-145, OPG, RANK and RANKL in THP-1 cells were assessed by RT-PCR, and the protein expression levels of OPG, RANK and RANKL were assessed by western blotting.

Results

The expression of miR-145 in the lentivirus-mediated miR-145 group was significantly up-regulated compared with that in the control and normal groups (both P < 0.01). Serum OPG levels were decreased in SINFH rats compared with control and normal rats. The mRNA and protein expression levels of OPG in THP-1 cells decreased after transfection (all P < 0.05). By contrast, the mRNA and protein expression levels of RANK and RANKL in THP-1 cells increased after transfection (all P < 0.05). After transfection of 293T cells with an miR-145 overexpression vector, miR-145 expression in 293T cells increased significantly, while OPG mRNA and protein expression decreased significantly (all P < 0.05).

Conclusion

MiR-145 plays a role in the occurrence of SINFH by targeting the OPG/RANK/RANKL signaling pathway.

Aseptic necrosis of the femoral head after pregnancy: a case report

A documented case of beginning aseptic necrosis of the femoral head associated with pregnancy together with a review of the literature about this rare complication of pregnancy is presented. The known risk factors of osteonecrosis are; steroid use, alcoholism, organ transplantation, especially after kidney transplant or bone marrow transplantation bone, systemic lupus erythematosus, dyslipidemia especially hypertriglyceridemia, dysbaric decompression sickness, drepanocytosis and Gaucher's disease. Among the less established factors, we mention procoagulations abnormalities, HIV infection, chemotherapy. We report a case of osteonecrosis of femoral head after pregnancy.

Association between open or closed reduction and avascular necrosis in developmental dysplasia of the hip: A PRISMA-compliant meta-analysis of observational studies

BACKGROUND

The risk of avascular necrosis of the femoral head (AVN) after treatment of developmental dysplasia of the hip is associated with the method of reduction. Some authors have suggested that open reduction is a risk factor for AVN; however, this is controversial. To our knowledge, a quantitative comparison of the incidence of AVN between closed and open reduction has not been conducted.

METHODS

Published studies were identified by searching PubMed, EMBASE, and the Cochrane Library up to May, 2015, focusing on the incidence of AVN after closed or open reduction for developmental dysplasia of the hip in children aged <3 years. Patients were age-matched who were treated by either closed or open reduction, but without pelvic or femoral osteotomy. Two authors independently assessed eligibility and abstracted data. Discrepancies were discussed and resolved by consensus. We pooled the odds ratios (ORs) and 95% confidence intervals (95%CIs) from individual studies using a random-effects model and evaluated heterogeneity and publication bias.

RESULTS

Nine retrospective studies were included in this analysis. The pooled OR for comparing open reduction with closed reduction for all grades of AVN was 2.26 (95%CI = 1.21-4.22), with moderate heterogeneity (I = 44.7%, P = 0.107). The pooled OR for grades II to IV AVN was 2.46 (95%CI = 0.93-6.51), with high heterogeneity (I = 69.6%, P = 0.003). A significant association was also found for the further surgery between open and closed reduction, with a pooled OR of 0.30 (95%CI = 0.15-0.60) and moderate heterogeneity (I = 46.4%, P = 0.133). No evidence of publication bias or significant heterogeneity between subgroups was detected by meta-regression analyses.

CONCLUSION

Findings from this meta-analysis suggest that open reduction is a risk factor for the development of AVN compared with closed treatment. Future studies are warranted to investigate how open reduction combined with pelvis and/or femoral osteotomy affects the incidence of AVN.

OPG and RANKL polymorphisms are associated with alcohol-induced osteonecrosis of the femoral head in the north area of China population in men

Alcohol-induced osteonecrosis of the femoral head (ONFH) is an important pathogenesis of nontraumatic ONFH. However, the mechanisms of the pathogenesis are still unknown. Osteoprotegerin (OPG) and receptor activator of nuclear factor-kappa B ligand (RANKL) have been implicated in multiple functions including blocking osteoclast maturation, controlling vascular calcifications, and promoting tumor growth and metastasis. The purpose of this article was to explore the association between OPG and RANKL gene variants and alcohol-induced ONFH. Six hundred seventy male subjects (335 patients and 335 normal individuals) were enrolled in our study. We selected 24 single-nucleotide polymorphisms (SNPs) to evaluate the association between genetic susceptibility variants and alcohol-induced ONFH using the chi-square test and gene model analysis. Overall, the OPG SNPs (rs1032128 and rs11573828) were associated with the strongest increased risk of alcohol-induced ONFH in the recessive model (rs1032128: odds ratio [OR] 1.49, 95% confidence interval [CI] 1.00-2.22, P = 0.04 for G/A; rs11573828: OR 3.32, 95% CI 1.07-10.30, P = 0.03 for T/C). The RANKL SNP rs2200287 was also an increased risk factor (OR 3.65, 95% CI 1.53-8.47, P = 0.003 for T/C) in the recessive model. The rs11573856, rs3134056, and rs1564861 SNPs were considered protective factors for alcohol-induced ONFH. We concluded that OPG and RANKL polymorphisms were associated with the occurrence of alcohol-induced ONFH.

Osteonecrosis of the femoral head, nonunion and potential risk factors in Pauwels grade-3 femoral neck fractures: A retrospective cohort study

The present study was to analyze clinical outcome of Pauwels grade-3 femoral neck fractures treated by different surgical techniques. Potential risk factors associated with nonunion and osteonecrosis of the femoral head (ONFH) were investigated as well. The retrospective study comprised of 67 sequential patients treated between January 2008 and December 2011. Patients with Pauwels grade-3 femoral neck fractures were treated by operative reduction and internal fixation. Cannulated screws (CS) were used in 46 patients, dynamic hip screw plus CS (DHS+CS) in 14, and locking compression plate (LCP) for proximal femur in 7. Reduction quality was assessed according to Haidukewych criteria. Postoperative radiographic examinations were conducted to observe fracture healing. Fracture displacement, comminution, fashion of internal fixation, and the sliding effect were analyzed, regarding the incidence of nonunion and ONFH. All patients had a follow-up of 21.6 ± 6.0 months on average. The phenomenon of sliding effect was observed in 16 cases (23.9%). In terms of reduction quality, 64 cases were graded as excellent, 2 were good, and 1 was poor. ONFH was presented in 15 cases (22.4%) and nonunion was found in 8 (11.9%), with 1 patient had ONFH and nonunion concomitantly. Profound hip contour was preserved in 45 cases (67.2%). The fashion of internal fixation yielded different results regarding ONFH and nonunion, whereas the effects of fracture displacement, comminution, and the sliding effect were not significant. ONFH and nonunion were common complications following Pauwels grade-3 femoral neck fractures. Higher incidence of ONFH in DHS+CS and of nonunion in the LCP group should be noted.

Guideline for Diagnostic and Treatment of Osteonecrosis of the Femoral Head

There is a new knowledge for clinical presentations and findings of imagine in patients with osteonecrosis of the femoral head (ONFH) in recent more than ten years. According to clinical data in Chinese huge patients with ONFH, the guideline for diagnosis and treatment of ONFH has been put forward by Chinese specialists. The newer contents of guideline include the definition for predisposing risk factors of ONFH, the new knowledge for clinical manifestations, the new interpretation for changes of imagine, important differential diagnosis. Based on the supplementary and revision for widely used staging and classification system, the new Chinese staging and classification system have been established. The advantages of Chinese staging and classification system accord with clinical and pathological features, it could be predicted the prognosis, and clinical applications are convenient. The guideline gives a brief account of principles for treatment selection and treatment methods for enhancement of diagnosis and treatment for ONFH.

Femoral Head Avascular Necrosis Is Not Caused by Arthroscopic Posterolateral Femoroplasty

This study was conducted to identify the risk of avascular necrosis of the femoral head after arthroscopic femoroplasty extending to the posterolateral femoral neck, the source of the primary blood supply to the femoral head. Cam lesions of femoroacetabular impingement are typically anterior along the junction of the femoral head and neck. However, anatomic variations can involve the posterolateral vascular region of the femoral head and neck. Femoroplasty involving this vascular region can lead to injury to the blood supply to the femoral head, with subsequent avascular necrosis. If the posterolateral portion of the cam lesion is preserved, persistent femoroacetabular impingement may occur. A retrospective review identified 112 patients who underwent arthroscopic femoroplasty for femoroacetabular impingement over a 2-year period. Of these patients, 14 had femoroplasty that extended to the posterolateral femoral head. Of this group, 5 had undergone magnetic resonance imaging (MRI) after femoroplasty and the other 9 were contacted to undergo MRI of the hip to evaluate for avascular necrosis. A radiologist and the senior author evaluated all MRI scans specifically for avascular necrosis of the femoral head. All procedures were performed by the senior author. Mean age of the 14 patients (8 women and 6 men) with femoroplasty that extended into the posterolateral vascular region of the femoral head was 44 years (range, 23-69 years). All 14 patients underwent MRI evaluation of the affected hip a mean of 25 months (range, 7-44 months) after femoroplasty. No MRI scans showed evidence of avascular necrosis of the femoral head. Femoroplasty of the posterolateral vascular region of the femoral head is not associated with avascular necrosis. Patients with femoroacetabular impingement and a cam lesion extending to the posterolateral femoral head can undergo femoroplasty of this region without the development of avascular necrosis. [Orthopedics. 2016; 39(3):177-180.].

Histopathological aspects and staging systems in non-traumatic femoral head osteonecrosis: an overview of the literature

BACKGROUND

The pathogenesis of non traumatic osteonecrosis of the femoral head (ONFH) has not yet been established. The literature shows a variable nomenclatura for this condition that often leads to confusion. Several risk factors have been identified but histopathological and radiological outcomes are common.

PURPOSE

To provide the overview on the current knowledges about the nomenclatura, etiology, disease progression, relationship between histopathological changes and imaging techniques in order to stage the disease accurately. Etiology and pathogenesis: Genetic predisposition, metabolic factors, local factors affecting blood supply such as vascular damage, increased intraosseous pressure and mechanical stress are involved in this desease. The final results are bone ischemia and infarction getting bone deathand FH collapse. Histopathological aspects and staging systems: Several staging systems have been developed to stage ONFH based on imaging techniques.The  subchondral collapse, the size or quantification of the lesion, and the lesion location within the femoral head are identified as the most important prognostic factors in ONFH disease. Histological analysis plays a critical role to evaluate the quality of necrotic area and the differences between microscopic, macroscopic and imaging outcomes were detected.

CONCLUSIONS

an ideal staging system is necessary to stage ONFH desease to detect several aspects, but itìs more difficult to create. At the present time we summarize some aspects that are advisable to focus during ONFH for the correct treatment.

[CLINICAL APPLICATION OF THREE DIMENSIONAL PRINTED NAVIGATION TEMPLATES FOR TREATMENT OF OSTEONECROSIS OF FEMORAL HEAD WITH PEDICLED ILIAC BONE GRAFT]

OBJECTIVE

To investigate the feasibility and early effectiveness to treat osteonecrosis of the femoral head (ONFH) with pedicled iliac bone graft assisted by individual digital design and three dimensional (3D) printed navigation templates.

METHODS

Between February and June 2014, 15 patients (24 hips) with ONFH underwent pedicled iliac bone graft assisted by individual digital design and 3D printed navigation templates. There were 11 males (17 hips) and 4 females (7 hips) with a mean age of 38 years (range, 18-56 years) and a mean disease duration of 7.5 months (range, 1-24 months); the left hip was involved in 2 cases, the right hip in 4 cases, and both hips in 9 cases. There were 7 cases (12 hips) of steroid-induced ONFH, 5 cases (8 hips) of alcohol-induced ONFH, 1 case (1 hip) of traumatic ONFH, and 2 cases (3 hips) of idiopathic ONFH. The preoperative Harris score was 56.60 ± 6.97. According to Association Research Circulation Osseous (ARCO) staging system, 5 hips were classified as stage IIB, 8 hips as stage IIC, 6 hips as stage IIIB, and 5 hips as stage IIIC. The navigation templates were designed and printed to assist accurate location and debridement of necrosis area according to preoperative CT scanning at the beginning of pedicled iliac bone grafting procedure.

RESULTS

The mean operation time was 135 minutes (range, 120-160 minutes), mean amount of bleeding was 255 mL (range, 200-300 mL). All the wounds healed primarily, no complication of deep vein thrombosis or infection was observed. All patients were followed up 12-16 months (mean, 14 months). The location of necrosis area was in accordance with preoperative design, which was removed completely without penetration of joint surface, pedicled iliac bone graft was performed at the right site according to postoperative imaging examination. Radiographically, graft fusion was achieved at 2.7 months (range, 2-3 months) in all patients. All the hips had no collapse during follow-up. Hip pain was relieved, and range of motion was improved. The Harris score was significantly improved to 89.53 ± 5.83 at last follow-up (t = 14.3 19, P = 0.000). The results were excellent in 12 hips, good in 10 hips, and fair in 2 hips according to Harris score standard.

CONCLUSION

Pedicled iliac bone graft assisted by individual digital design and 3D printed navigation templates for treatment of adult ONFH has the advantages of accurate location and complete debridement of necrosis area, so satisfactory results can be obtained.

[OBSERVATION OF EFFECTIVENESS OF HIP RESURFACING ARTHROPLASTY IN TREATMENT OF OSTEONECROSIS OF FEMORAL HEAD IN YOUNG AND MIDDLE-AGED PATIENTS]

OBJECTIVE

To evaluate the clinical and radiographic outcomes of hip resurfacing arthroplasty (HRA) for treating osteonecrosis of the femoral head (ONFH) in young and middle-aged patients.

METHODS

Between January 2008 and April 2009, 34 patients with ONFH underwent HRA. There were 19 males and 15 females with an average age of 54 years (range, 33-59 years). Of 34 cases, 16 left hips and 18 right hips were involved, including 9 cases of alcohol-induced ONFH, 8 cases of steroid-induced ONFH, 7 cases of traumatic ONFH, and 10 cases of unexplained ONFH. According to modified Ficat classification system, 26 hips were rated as stage III, and 8 hips as stage IV. The Harris hip score (HHS) and modified University of California, Los Angeles (UCLA) activity score were used to evaluate the clinical results. Migration of prosthesis was assessed on the anteroposterior radiographs. The abduction angle was measured on the acetabular side. On the femoral side, varus-valgus shift was determined by measurement of stem-shaft angle. The axial collapse of femoral component was assessed with the component-lateral cortex ratio.

RESULTS

Healing of incision by first intention was achieved in all patients without complications of infection and thrombosis of deep vein of lower extremities. Thirty-two patients were followed up 78 months on average (range, 70-84 months). No implant loosening, infection, femoral neck fracture, dislocation, and inflammatory pseudotumor were observed. At last follow-up, the HHS score was significantly increased to 95.22 +/- 1.47 from preoperative 50.10 +/- 2.27 (t=1.510, P=0.008). Modified UCLA activity score was significantly increased to 7.70 +/- 1.13 from preoperative 3.90 +/- 0.90 (t=0.830, P=0.003). The abduction angle, stem-shaft angle, and compotent-lateral cortex ratio showed no significant difference between at 3 days after operation and last follow-up (P>0.05).

CONCLUSION

If the indication of operation is mastered strictly, HRA may be effective in treatment for ONFH at Ficat stage III or IV in young and middle-aged patients.

[EFFECTIVENESS OF MODIFIED Urbaniak OPERATION TO TREAT AVASCULAR NECROSIS OF THE FEMORAL HEAD]

OBJECTIVE

To investigate the effectiveness of the modified Urbaniak operation to treat avascularnecrosis of the femoral head (ANFH).

METHODS

A retrospective analysis was made on the clinical data of 38 patients (41hips) with ANFH treated between February 2010 and October 2012 with the modified Urbaniak operation (to add lateralfemoral incision based on femoral greater trochanter incision, to preserve the original fibula flap drilling, decompressionand filling through trochanteric outer cortex, and to select the descending branch of lateral circumflex femoral artery asthe supply vessel). Of 38 cases, 25 were male (28 hips), 13 were female (13 hips), aged 16-52 years (mean, 34 years); therewere 19 cases (21 hips) of alcoholic ANFH, 9 cases (9 hips) of traumatic ANFH, 5 cases (6 hips) of hormone ANFH, and5 cases (5 hips) of idiopathic ANFH. The disease duration ranged from 10 months to 6 years (mean, 3.7 years). According to Ficat staging criteria, 24 hips were rated as stages II and 17 hips as stage III. The preoperative Harris hip scores were80.63 ± 5.02 and 77.06 ± 6.77 in patients at stage II and III respectively. The related complications were recorded afteroperation. According to the findings of postoperative X-ray films, 4 grades were improvement, stabilization, deterioration,and failure; improvement or stabilization was determined to radiological success. According to the Harris score toevaluate the function of hips, more than 80 was determined to clinical success.

RESULTS

Healing by first intention wasachieved in all patients after operation. Three cases had numbness and hypoaesthesia of the lateral femoral skin, 1 case had abnormal sensation of the dorsal foot, which had no effect on daily life. Thirty-eight cases (41 hips) were followed up 1 year to 3 years and 3 months (mean, 2 years and 3 months). There was no complication such as hip joint stiffness, hip or groin persistent pain, hip joint infection, or ankle instability. At last follow-up, the X-ray films showed improvement in 23 hips (56.1%), stabilization in 17 hips (41.5%), and deterioration in 1 hip (2.4%); 40 hips obtained the radiological success. According to the Harris score, the results were excellent in 17 hips, good in 20 hips, fair in 3 hips, and poor in 1 hip with an excellent and good rate of 90.2%; 37 hips achieved the clinical success. The Harris scores were 89.92 ± 4.12 and 86.53 ± 5.70 in patients at stage II and III respectively at last follow-up, showing significant differences when compared with preoperative ones (t = 7.011, P = 0.000; t = 4.412, P = 0.000).

CONCLUSION

The modified Urbaniak operation has the advantages of more convenient operation, less complications, higher safety, and better hip functional recovery. It is effective method to treat ANFH.

Etiologies and outcome of osteonecrosis of the femoral head: Etiology and outcome study in a Taiwan population

BACKGROUND

Osteonecrosis of the femoral head (ONFH) is an important indication for total hip arthroplasty in Taiwan. We demonstrated the etiologies of ONFH and outcomes based on stratification of patients according to different etiologies.

METHODS

We reviewed medical records and images from January 2000 to May 2010 in our database with the diagnosis of "osteonecrosis of the femoral head." We categorized all patients into different etiologies, including corticosteroid, alcohol, and idiopathic. All patients received subsequent follow up for ipsilateral precollapse ONFH and contralateral disease-free femoral head status after initial diagnosis.

RESULTS

Of the 1153 patients who had undergone 1674 hip surgeries including core decompression and total hip replacement, alcohol use was the most prevalent etiology in our population (45.2%). Patients with corticosteroid- and alcohol-associated ONFH were younger and more likely to have bilateral disease. Patients with alcohol- or steroid-associated ONFH were found to have a higher rate of contralateral disease and faster progression of precollapse ONFH than patients who had or had not undergone core decompression.

CONCLUSION

Alcohol use had the greatest impact on ONFH in our population. Nonidiopathic ONFH patients had the worst outcome. Understanding the nature of progression of ONFH and incidence of contralateral disease may provide great prognostic value to detect and perform early intervention.

The role of sclerotic changes in the starting mechanisms of collapse: A histomorphometric and FEM study on the femoral head of osteonecrosis

PURPOSE

To assess the distributions of stress, strain, and fractured areas using a finite element model (FEM), and examine the osteoclastic activity histopathologically in osteonecrosis of the femoral head.

METHODS

Three femoral heads were obtained during hip arthroplasty for femoral head osteonecrosis. One sample with a normal area, two samples with a non-sclerotic boundary without collapse (Type 1), two samples with a non-collapsed sclerotic boundary (Type 2), and two samples with a collapsed sclerotic boundary (Type 3) were collected from each femoral head for the FEM and histopathological analyses. FEM was performed using CT data, and the distributions of von Mises equivalent stress, octahedral shear stress, octahedral shear strain, and simulated fractured area were evaluated. Furthermore, the osteoclast count at the boundary was compared for each type.

RESULTS

In normal and Type 1 samples, the distributions of von Mises equivalent stress, octahedral shear stress, octahedral shear strain, and the fractured area were equally concentrated along the whole analytical range; however, in the Type 2 and 3 samples, they were concentrated along the thickened bone trabeculae at the boundary, which corresponded to the fractured area. Histopathologically, a significantly increased osteoclast number was observed only at the collapsed sclerotic boundary.

CONCLUSION

These results demonstrated that both shear stress and shear strain tend to be concentrated on thickened bone trabeculae at the boundary. Fracture analyses revealed that the boundary of sclerotic changes, which results from the repair process, may be the starting point of the fracture. Additionally, the osteoclastic activity increases after collapse.

Greater Trochanteric Fragmentation After Failed Metal-on-Metal Hip Arthroplasty

Adverse reaction to metal debris (ARMD) involving the hip joint has emerged as an important reason for failure and revision among patients with metal-on-metal (MOM) hip arthroplasty. To the authors' knowledge, there are no reports of adverse radiographic sequelae in the greater trochanter subsequent to revision for ARMD. The authors describe clinical and radiographic findings in 2 patients who developed greater trochanteric fragmentation 1 to 2 years after conversion of their failed MOM hips to polyethylene bearings. Both patients had solid pseudotumors with tissue necrosis. Several reports describe various clinical features of ARMD. Although poor outcomes have been demonstrated after some MOM revisions, to the authors' knowledge, no reports document greater trochanter fragmentation in ARMD. The current patients highlight the fact that tissue damage occurring with MOM bearing hips can involve bone in addition to soft tissue even after a pseudotumor has been removed and serum metal levels have decreased to normal levels after revision. Unlike the greater trochanteric fractures historically associated with polyethylene wear and osteolysis, no evidence of bone cysts or lesions was found prior to the fractures and neither fracture healed with conservative treatment. For these 2 patients, the authors believe the tissue necrosis included both soft tissue and bone. The necrotic bone resorbed gradually after removal of the MOM bearing, resulting in bone fragmentation with ongoing symptoms. These patients emphasize and remind us that damage is not only limited to soft tissues, but also includes bone. Surgeons should be aware of this radiographic finding and the associated clinical symptoms.

[Nontraumatic causes of bilateral avascular necrosis of the femoral head: link between hepatitis C and pegylated interferon]

BACKGROUND

Avascular necrosis of the femoral head is a frequent condition in patients with a history of trauma. The major pathologic causes include vascular diseases, malignancies, hypercoagulability states, long-term steroid treatment, and some patients have a history of hepatitis C infection treated with pegylated interferon and ribavirin. Upon studying the behavior of the hepatitis C virus, Seef, Foster and Poynard found a hypercoagulability state that causes interruption of retinacular blood flow to the femoral head, without an increased incidence of osteonecrosis in this patient group. Lauer states that such viral infections involve an autoimmune process and may result in transient vasculitides. Giampaolo, in 2005, reported the relationship between interferon use for multiple myeloma and other cancers and femoral avascular necrosis.

MATERIAL AND METHODS

Cases with a diagnosis of bilateral osteonecrosis of the femoral head were assessed.

RESULTS

Five patients were included, 4 females and one male, with a diagnosis of bilateral osteonecrosis of the femoral head. All of them had history of hepatitis C infection treated with pegylated interferon. The final diagnosis was proven by pathology after arthroplasty. A literature review was made of articles on the relationship between this condition and interferon use in patients with hepatitis C infection.

CONCLUSIONS

Finding out the relationship between viral diseases such as hepatitis B and C infection and hypercoagulability states, autoimmune processes leading to transient vasculitides and the use of pegylated interferon 2B, will help us discover new nontraumatic causes associated with this condition.

[Neglected traumatic dislocation of the hip treated with total hip arthroplasty: report of 2 cases]

Les luxations négligées de la hanche sont des lésions exceptionnelles. Elle concerne généralement des traumatismes graves, où les lésions ostéo-articulaires ne sont pas minutieusement recherchées, ou relayer au second plan. L’évolution inéluctable se fait vers la nécrose de la tête fémorale et la coxarthrose. L'arthroplastie permet de raccourcir cette évolution et de réinsérer rapidement ces patients.

Combined effect of tnf-α polymorphisms and hypoxia on steroid-induced osteonecrosis of femoral head

OBJECTIVE

Tumor necrosis factor (TNF)-α is a proinflammatory cytokine, some studies reported that TNF-α gene plays important role in the pathogenesis of SONFH. And the polymorphisms of TNF-α were presented as risk factors for steroid-induced osteonecrosis of the femoral head (SONFH). Meanwhile, various environment factors involve in the pathogenesis of SONFH. Our study aimed to investigate the interaction effect of TNF-α polymorphisms and hypoxia factor on SONFH.

METHODS

120 patients with SONFH and 100 healthy people, matched with the cases on age and sex, participated in this study. DNA was extracted from all participants. According to previous studies, genotyping of TNF-α polymorphisms (rs1800629, rs1799964 and rs1800630) was tested with the method of PCR-RDB (Reverse Dot Blot). Environmental factors were also chose. Logistic regression analysis was used to analyze the interaction between TNF-α polymorphisms and environment factors on SONFH.

RESULTS

The polymorphisms of rs1800629 and rs1800630 were significantly associated with SONFH (OR: 3.70, 9.93). Patients with hypoxia history were found higher (65.00%) compared with the healthy controls (43.00%). For the person with hypoxic history, GG and AG+AA genotypes of rs1800629 could increase their risk to suffer SONFH (OR: 2.12, 3.78). If the patients with the variant genotypes of rs1800630 experienced hypoxia state, then the risk for SONFH increased 2.41 folds.

CONCLUSION

We concluded that the onset of SONFH was influenced by TNF-α and hypoxia history. There existed strong interaction between TNF-α and hypoxia history.

[PEDICLED ILIAC PERIOSTEAL FLAP GRAFT FOR AVASCULAR NECROSIS OF FEMORAL HEAD AFTER FEMORAL NECK FRACTURE IN ADOLESCENTS]

OBJECTIVE

To assess the effectiveness of pedicled iliac periosteal flap graft for treatment of avascular necrosis of the femoral head (ANFH) after femoral neck fracture in adolescents.

METHODS

Between December 2006 and August 2011, 9 patients (9 hips) with ANFH after femoral neck fracture were treated with pedicled iliac periosteal flap graft. There were 6 males and 3 females with an average age of 14.7 years (range, 10-18 years). Fractures were caused by traffic accident injury (5 cases), falling injury from height (3 cases), and fall injury (1 case). The time from injury to internal fixation with Kirschner wires or cannulated screws was 3-16 days, and all fractures healed within 10 months after internal fixation. The interval between fracture fixation and ANFH was 10-42 months (mean, 24.4 months). According to Steinberg staging system, 1 hip was classified as stage IIIb, 2 hips as stage IIIc, 1 hip as stage IVa, 3 hips as stage IVb, and 2 hips as stage IVc. The Harris scores and Steinberg classification were compared between at pre- and post-operation to assess the outcomes clinically and radiologically.

RESULTS

All incisions healed by first intention. No complications of infection, deep venous thrombosis of lower limb, and pain and numbness of donor site were observed during or after operation. All patients were followed up 38-76 months (mean, 52 months). Joint pain was relieved; no leg length discrepancy was observed; the walking gait was improved and range of motion of hips was increased. The Harris score was significantly increased from 62.8 ± 3.6 at pre-operation to 92.7 ± 9.9 at last follow-up, showing significant difference (t = -12.244, P = 0.000). The hip function was excellent in 5 hips, good in 3 hips, and poor in 1 hip, and the excellent and good rate was 88.89%. Post-operative radiological assessment demonstrated that only 1 hip (stage IIIb) had further collapse of the femoral head, the other hips had no incidence of deterioration. The radiological success rate was 88.89% (8/9).

CONCLUSION

The pedicled iliac periosteal flap graft for ANFH after femoral neck fracture in adolescents can provide good osteogenesis and vascular reconstruction of the femoral head.

Predictive value of single photon emission computerized tomography and computerized tomography in osteonecrosis after femoral neck fracture: a prospective study

PURPOSE

Osteonecrosis of the femoral head (ONFH) is a very common complication after femoral neck fracture. The purpose of this study was to assess the femoral head vascularity after femoral neck fracture using single photon emission computerized tomography and computerized tomography (SPECT/CT), and to evaluate its value in predicting ONFH.

METHODS

Between January 2008 and March 2011, 120 patients diagnosed with femoral neck fracture underwent SPECT-CT before the internal fixation. The fracture was classified according to the Garden classification. The ratios of the radionuclide uptake of the fractured femoral head to that of the contralateral femoral head (F/N) were calculated to assess the femoral head vascularity. After a minimum of two years' follow-up, magnetic resonance imaging (MRI) was used as the "gold standard" for the diagnosis of possible ONFH.

RESULTS

A total of 114 patients completed the study. The SPECT/CT examination showed that the F/N ratios of Garden I, II, III and IV were 2.6, 1.8, 0.8, and 0.6, respectively. At the time of the most recent follow-up, osteonecrosis developed in two of the 27 patients who had a Garden Stage-II fracture, in eight of the 34 patients who had a Garden Stage-III fracture, and nine of the 27 patients who had a Garden Stage-VI fracture. With a cutoff of 0.55 from the receiver operating characteristic (ROC) curve, F/N ratio showed a sensitivity of 97%, a specificity of 79%, a positive predictive value of 95%, and a negative predictive value of 19%.

CONCLUSION

SPECT-CT proved to be reliable and valid for predicting ONFH after femoral neck fracture.

[Fracture Type and Injury-to-Surgery Interval as Risk Factors for Avascular Necrosis of the Femoral Head after Internal Fixation of Intracapsular Femoral Neck Fracture]

PURPOSE OF THE STUDY

The aim of the study was to investigate the occurrence of avascular necrosis (AVN) of the femoral head following the osteosynthesis of intracapsular fracture of the femoral neck in relation to the time interval between injury and surgery and the type of fracture.

MATERIAL AND METHODS

The data of patients with intracapsular fractures of the femoral neck surgically treated in the period from 2001 to 2011 were reviewed. Of 1555 patients treated for this fracture, 125 (7%) underwent osteosynthesis. The evaluated group included 115 patients who came for examination at one-year follow-up. There were 59 (52%) women and 56 (48%) men. Dynamic hip screw (DHS) osteosynthesis with an anti-rotation screw was performed in 103 patients and lag-screw osteosynthesis involving three parallel cannulated cancellous screws was employed in 12 patients. The patients were allocated to groups according to the injury-to-surgery interval and to sub-groups on the basis of the Garden classification of femoral fracture stage.

RESULTS

In the group of 58 patients treated within 6 h of injury, AVN developed in 10 (17%). When the type of fracture was considered, 4% of the non-displaced fractures and 30% of the displaced fractures developed AVN. The patients with Garden stage I and II (non-displaced) fractures treated within 6 h of injury had a significantly lower risk of AVN development than those with Garden stage III or IV (displaced) fractures. The group treated between 6 and 24 post-injury hours comprised 21 patients, of whom four (19%) had AVN. In non-displaced and displaced fracture sub-groups, 25% of the patients in the former and 16% in the latter had AVN. The stage of displacement had no effect on AVN development. The two groups together (patients treated by 24 h) had a significantly lower AVN incidence than the patients treated after 24 h (p = 0.0025). In this group of 36 patients, 16 had AVN (44%) and the fracture stage made no significant difference (p = 0.6985; nondisplacement sub-group, 41%; displacement sub-group, 55%).

CONCLUSIONS

The study showed a significantly lower AVN occurrence in the patients surgically treated within 24 h of injury. In the patients treated within 6 h of injury, AVN incidence was significantly lower in the patients with non-displaced fractures, as compared with those who had displaced fractures. This was not true for the two patient groups treated later (6-24 and later than 24 h) in which the differences between AVN development after non-displaced fractures and that after displaced fractures were similar.

Analysis of risk factors for femoral head necrosis after internal fixation in femoral neck fractures

Femoral head necrosis is a rare but devastating complication following femoral neck fracture. The reported incidence of avascular necrosis after femoral neck fracture fixation varies widely, and there is no consensus regarding its risk factors. The aim of this study was to analyze the risk factors for femoral head necrosis after internal fixation in femoral neck fracture. This retrospective study included 166 patients with femoral neck fractures treated with surgical reduction and internal fixation at the authors' institution from January 2004 to December 2008. Eight patients died for reasons unrelated to the surgery, and 12 patients were lost to follow-up. The remaining 146 patients (146 fractures) were followed until union or until conversion to total hip arthroplasty. The patients included 61 males and 85 females with an average age of 47.5 years (range, 18-68 years). The authors analyzed the following factors: age, sex, Garden classification, reduction quality, surgical methods, injury-to-surgery interval, preoperative traction, weight-bearing time, and implant removal. All patients were followed for a mean of 52 months (range, 6-90 months). The incidence of femoral head necrosis was 14.4% (21/146). Garden classification (P=.012), reduction quality (P=.008), implant removal (P=.020), and preoperative traction (P=.003) were significantly associated with femoral head necrosis. Patient age (P=.990), sex (P=.287), injury-to-surgery interval (P=.360), weight-bearing time (P=.868), and surgical methods (P=.987) were not significantly associated with femoral head necrosis. In multivariate logistic regression analysis, implant removal was not a significant risk factor for femoral head necrosis development (P=.498). Garden classification, reduction quality, and preoperative traction had a significant effect on femoral head necrosis development.

The most important risk factors for avascular necrosis and chondrolysis in patients with slipped capital femoral epiphysis

OBJECTIVE

To study the most important risk factors for avascular necrosis (AVN) and chondrolysis in children with slipped capital femoral epiphysis (SCFE).

MATERIAL AND METHOD

Thirty patients with SCFE, who were surgically treated by single-screw fixation with goodpositioning from 1998 to 2012, were reviewed (22 male and 8 female patients, 35 hips; bilateral involvement in 1 male and 4 female patients). The following clinical and radiographic data were analyzed: age, sex, weight, height, onset, grading, stability, severity, history of trauma, anterior physeal separation (APS), and major complications such as AVN and chondrolysis. The results were reported according to the Heyman and Herndon criteria as excellent, good, fair, poor or failure. Multiple logistic regression was used to identify multivariate predictors of osteonecrosis and chondrolysis.

RESULTS

The mean patient age was 11.9 years. The right and left sides were affected in 45.7% and 54.3% of patients, respectively. There were 2 acute (5.7%), 26 chronic (74.3%), 5 acute-on-chronic (14.3%), and 2 preslips (5.7%). Five hips were unstable (14.3%), and 30 were stable (85.7%). There were 14 mild slips (40%), 6 moderate slips (17.1%), and 15 severe slips (42.9%). Thirteen hips (37.1%) had a history oftrauma. APS waspresent in 12 hips (34.3%). Nine hips hadAVN (25.7%), 7 had chondrolysis (20.0%), and 10 had both AVN and chondrolysis (28.6%). Clinical results were excellent, good, fair, poor, and failure in 13 (37.1%), 12 (34.3%), 6(17.1%), 2 (5.7%), and 2 hips (5.7%), respectively. Univariate analysis revealed that the statistically significant risk factors (p < 0.05) for A VN and chondrolysis were the presence of APS (p = 0.000), acute and acute-on-chronic onset (p = 0.001), moderate and severe grades (p = 0. 002), instability (p = 0.17), and a history of trauma (p = 0.02). Multivariate analysis revealed that the presence of APS was the only risk factor for AVN and chondrolysis with the highest statistical significance (p = 0.000).

CONCLUSION

Single-screw fixation gave good and reliable outcomes in most cases. APS is the most important risk factor for AVN and chondrolysis in patients with SCFE. The optimal alternative treatment to reduce this major complication should be further studied, especially in patients with acute or acute-on-chronic slips, unstable hips, a history of trauma, or APS.

[Short- and medium-term effectivenesses of stemless hip arthroplasty for treating hip joint disease in young and middle-aged patients]

OBJECTIVE

To summarize the short- and medium-term effectivenesses of stemless hip arthroplasty for treating hip joint disease in young and middle-aged patients.

METHODS

Between June 2005 and December 2010, 25 cases (27 hips) of hip joint disease were treated with stemless hip arthroplasty. There were 17 males (19 hips) and 8 females (8 hips) with an average age of 45.6 years (range, 30-57 years), including 13 left hips, 10 right hips, and 2 bilateral hips. The causes included avascular necrosis of the femoral head (ANFH) secondary to femoral neck fracture in 5 cases (5 hips), ANFH in 15 cases (16 hips), osteoarthritis of the hip joint caused by ankylosing spondylitis in 2 cases (3 hips), osteoarthritis of the hip joint caused by dysplasia of acetabular in 2 cases (2 hips), and rheumatoid arthritis in 1 case (1 hip). The disease duration was 1-17 years (mean, 6.1 years). Before operation, the Harris score was 47.6 ± 14.2.

RESULTS

The incision healed by first intention in all patients, and no complications occurred, such as infection, periprosthetic fracture, and deep vein thrombosis of lower extremity. Twenty-five patients (27 hips) were followed up 36-96 months (mean, 51 months). One case (1 hip) had sciatic nerve injury after operation, which was relieved by symptomatic treatment. One case (1 hip) had prosthesis loosening, which was relieved after revision. The survival rate of prosthesis was 96.3% (26/27). At last follow-up, the Harris score was 92.1 ± 3.6, which was significantly better than preoperative score (t = 18.241, P = 0.000). The excellent and good rate was 88.9% (excellent in 19 hips, good in 5 hips, fair in 2 hips, and poor in 1 hip). The X-ray films showed good location of prosthesis, and no evidence of dislocation, bone resorption, osteolysis, and heterotopic ossification.

CONCLUSION

Because of reserving femoral neck, biomechanics conduction and distribute of the proximal femur achieve natural biomechanics state of the human body. The short- and medium-term effectivenesses of stemless hip arthroplasty for treating hip joint disease in young and middle-aged patients are satisfactory, but the long-term effectiveness need further observation.

PET/CT study of temporal variations in blood flow to the femoral head following low-energy fracture of the femoral neck

Earlier studies on femoral neck fractures have assessed the blood flow in either the pre- or postoperative period and information is lacking regarding changes in vascular flow to the femoral head after injury. Sixty-two adults with low-energy intracapsular femoral neck fractures were studied prospectively. Mean patient age was 57.2 years (range, 45-82 years). All patients underwent positron emission tomography/computed tomography (PET/CT) prior to surgical intervention and 6 weeks after internal fixation. Internal fixation was done using cannulated cancellous titanium screws and serial follow-up radiographs were obtained (at monthly intervals for the first 3 months followed by 3 monthly intervals between radiographs up to 2 years). On the preoperative PET/CT, 13 patients showed intact vascularity, 31 showed total loss of vascularity, and 18 showed partial loss of vascularity of the femoral head. The 6-week postoperative PET/CT scan showed recovery of blood supply in 23 of the 31 patients with total loss of vascularity and 15 of the 18 patients with partial loss of vascularity of the femoral head. Eleven of 62 patients had total or partial avascularity at the 6-week postoperative PET/CT scan and all 11 patients showed evidence of avascular necrosis on plain radiographs at the end of 2 years. The association between the vascular status of the femoral head at 6 weeks and avascular necrosis at the end of 2 years was statistically significant (P<.001). This study shows that the femoral head undergoes temporal variations in blood flow following femoral neck fracture. Decreased or absent vascularity is seen in approximately 75% of the fractures and 80% of the femoral heads with initial vascular compromise seem to regain blood flow within 6 weeks. Thus, prognostication about vascularity based on single-point preoperative imaging is difficult. The 6-week postoperative PET/CT scan seems to be reliable in predicting the future status of the femoral head. However, decision making regarding hemiarthroplasty or internal fixation at the time of injury may have to depend on factors other than the preoperative vascular status of the femoral head.