Osteonecrosis of the femoral head

Advancements in 3D printing technologies for personalized treatment of osteonecrosis of the femoral head

Three-dimensional (3D) printing technology has shown significant promise in the medical field, particularly in orthopedics, prosthetics, tissue engineering, and pharmaceutical preparations. This review focuses on the innovative application of 3D printing in addressing the challenges of osteonecrosis of the femoral head (ONFH). Unlike traditional hip replacement surgery, which is often suboptimal for younger patients, 3D printing offers precise localization of necrotic areas and the ability to create personalized implants. By integrating advanced biomaterials, this technology offers a promising strategy approach for early hip-preserving treatments. Additionally, 3D-printed bone tissue engineering scaffolds can mimic the natural bone environment, promoting bone regeneration and vascularization. In the future, the potential of 3D printing extends to combining with artificial intelligence for optimizing treatment plans, developing materials with enhanced bioactivity and compatibility, and translating these innovations from the laboratory to clinical practice. This review demonstrates how 3D printing technology uniquely addresses critical challenges in ONFH treatment, including insufficient vascularization, poor mechanical stability, and limited long-term success of conventional therapies. By introducing gradient porous scaffolds, bioactive material coatings, and AI-assisted design, this work outlines novel strategies to improve bone regeneration and personalized hip-preserving interventions. These advancements not only enhance treatment efficacy but also pave the way for translating laboratory findings into clinical applications.

Effect of Patient Age on Total Hip Arthroplasty Outcomes in Patients Who Have Osteonecrosis of the Femoral Head Compared to Patients Who Have Hip Osteoarthritis

BACKGROUND

Osteonecrosis of the femoral head (ONFH) affects both young and old patients. However, outcomes following total hip arthroplasty (THA) for these patients may vary with age. This study aimed to examine the effect of age on THA outcomes for non-traumatic ONFH patients, an area currently lacking research.

METHODS

Patients who had non-traumatic ONFH undergoing THA with at least 2 years of follow-up were identified using a database and divided into four groups by age. Then, 4 matched control groups of patients who had hip osteoarthritis (OA) were created. Multivariate logistic regression analyses were used to evaluate the rates of medical and surgical complications. Additionally, cohorts with a minimum 5-year follow-up were filtered to obtain further data on surgical outcomes. The study analyzed 85,462 non-traumatic ONFH and 80,120 hip OA patients undergoing THA.

RESULTS

Multiple medical complications in ONFH patients increased with age. Periprosthetic fracture within 2 years increased with age, while 90-day wound complications, 2-year periprosthetic joint infections, dislocations, and revisions decreased. The trends for complications continued at the 5-year follow-up. Compared to OA patients, those who had ONFH had higher risks of most complications, but this discrepancy decreased with age.

CONCLUSIONS

In ONFH patients undergoing THA, medical complications generally rise with age, while most surgical complications, including revisions, decrease. It is notable that ONFH patients experienced more complications than those who had OA, but this difference diminished with age.

Using Computed Tomography-Based Three-dimensional Modeling and Computer Navigation for Minimally Invasive Core Decompression and Adjuvant Orthobiologic Therapy of Femoral Head Avascular Necrosis

Avascular necrosis of the femoral head is a debilitating condition that can lead to femoral head collapse. Core decompression with adjuvant cellular therapies, such as bone marrow aspirate concentrate, delays disease progression and improves outcomes. However, inconsistent results in the literature may be due to limitations in surgical technique and difficulty in targeting the necrotic lesions. Here, we present a surgical technique utilizing computed tomography-based three-dimensional modeling and instrument tracking to guide the therapy to the center of the lesion. This method minimizes the number of attempts to reach the lesion and confirms the three-dimensional positioning of the instrumentation within the lesion. Our technique may improve the outcomes of core decompression and adjuvant therapy and prevent or delay hip collapse in patients with femoral head avascular necrosis.

Extension of the Antero-Posterior Necrotic Regions Associated With Collapse Cessation in Osteonecrosis of the Femoral Head

BACKGROUND

Collapse cessation is of utmost importance following a long period of collapse due to osteonecrosis of the femoral head (ONFH). This study investigated the relationship between collapse cessation and the extent of the necrotic regions of ONFH.

METHODS

Overall, 74 patients who had symptomatic ONFH (collapse < 3 mm) at the first visit with a minimum follow-up of 3 years were included in this study. Patients were categorized based on collapse progression or cessation into the progression and stable groups. The extent of the antero-posterior (AP) and medio-lateral necrotic regions between the groups was assessed using sagittal and coronal sections of T1-magnetic resonance imaging. Additionally, the most effective cutoff value was determined from the receiving operating characteristic curve where collapse cessation could be obtained, while the survival rates were determined with collapse progression as the endpoints were evaluated.

RESULTS

Overall, 45 and 29 patients were in the progression and stable groups, respectively. The AP and medio-lateral necrotic regions were significantly different (P < .01 and P < .01, respectively) between the progression and stable groups. A cutoff value of 62.1% of the AP necrotic regions was determined from the receiving operating characteristic curve analysis. The 5-year survival rates with collapse progression as the endpoints were 5.4 and 77.8% in the AP necrotic regions of ≥62.1 and <62.1%, respectively (P < .01).

CONCLUSIONS

Cases with AP necrotic regions of ≤62.1% can be expected to have collapse cessation, which could be a useful index for ONFH treatment strategies.

LEVEL OF EVIDENCE

Level IV.

The Effect of the Hip Flexion Angle in Osteonecrosis of the Femoral Head Based on China-Japan Friendship Hospital Classification - A Finite Element Study

OBJECTIVE

The alteration in the mechanical environment of the necrotic area is the primary cause of the collapse observed in osteonecrosis of the femoral head (ONFH). This study aims to evaluate the biomechanical implications of the China-Japan Friendship Hospital (CJFH) classification system and hip flexion angles on the necrotic area in ONFH using finite element analysis (FEA). The goal is to provide valuable guidance for hip preservation treatments and serve as a reference for clinical diagnosis and therapeutic interventions.

METHODS

Hip tomography CT scan data from a healthy volunteer was used to create a 3D model of the left hip. The model was preprocessed and imported into Solidworks 2018, based on the CJFH classification. Material parameters and boundary conditions were applied to each fractal model in ANSYS 21.0. Von Mises stresses were calculated, and maximum deformation values were obtained to evaluate the biomechanical effects of the load on the necrotic area and post-necrotic femur, as well as assess each fractal model's collapse risk.

RESULTS

(1) At the same hip flexion angle, maximum deformation followed this order: M Type < C Type < L Type. The L3 type necrotic area experienced the most significant deformation at 0, 60, and 110° angles (1.121, 1.7913, and 1.8239 mm respectively). (2) Under the same CJFH classification, maximum deformation values increased with hip flexion angle (0 < 60 < 110°), suggesting a higher risk of collapse at larger angles. (3) Von Mises stress results showed that the maximum stress was not located in the necrotic area but near the inner and outer edge of the femoral neck, indicating decreased stiffness and strength of the subchondral bone after osteonecrosis.

CONCLUSION

The study found that femoral head collapse risk was higher when the necrotic area was located in the lateral column under the same stress load and flexion angle. Mechanical properties of the necrotic area changed, resulting in decreased bone strength and stiffness. Large-angle hip flexion is more likely to cause excessive deformation of the necrotic area; thus, ONFH patients should reduce or avoid large-angle hip flexion during weight-bearing training in rehabilitation activities.

The effect of cocaine on patients undergoing total hip arthroplasty

Background

Cocaine use has surged in the past decade, with 4.8 million Americans (1.7% of the population greater than 12) reporting use in 2021, leading to a healthcare burden of 1.3 billion dollars. Cocaine users experience prolonged hospital stays, higher costs, worse surgical outcomes, increased risk of medical conditions, and inflammation-related osteoarthritis. The study aims to identify factors influencing length of stay, costs, and perioperative complications in cocaine users undergoing total hip arthroplasty (THA) to reduce these risks.

Methods

This study utilized the NIS database, providing comprehensive information on patient demographics, length of stay, hospital costs, and complications. Statistical analyses were conducted using SPSS software, including propensity matching and significance testing, to compare outcomes between cocaine users (CU) and non-cocaine users (NCU) undergoing total hip arthroplasty.

Results

After propensity matching, cocaine users had a significantly longer LOS (4.8 days) in comparison to non-cocaine users (2.6 days) (p < 0.001). Similarly, the CU group had a larger of care (87984.9) than the NCU group (69149.2) (p < 0.001). Cocaine users had significantly higher rates of blood loss anemia (OR: 3.24, 95% CI: 2.21, 4.73), blood loss anemia (OR: 1.59, 95% CI: 1.12, 2.24), blood transfusion (OR: 2.23, 95% CI: 1.04, 4.78), periprosthetic dislocation (OR: 6.57, 95% CI: 1.47, 29.32), and periprosthetic infection (OR: 4.59, 95% CI: 1.54, 13.68) than patients in the non-cocaine user's group.

Conclusion

Cocaine users had a significantly longer length of stay, higher costs of care, and an increased number of post-operative complications compared to non-cocaine users. These data contribute to understanding the potential ramifications of cocaine users undergoing THA.

Prognosis and risk prediction of bone impaction grafting through femoral head-neck fenestration: a retrospective cohort study

The bone impaction grafting through femoral head-neck fenestration was a favorable hip preservation procedure but without prognosis estimation. This study retrospectively reviewed 79 patients' clinical data (114 hips) with osteonecrosis of the femoral head (ONFH) who underwent this procedure from June 2009 to June 2019. By the end of June 2022, the median survival time of the hip was (74.13 ± 44.88) months, and the success rate of hip preservation was 68.42%. Lateral reserved angle (LPA) and combined reserved angle (CPA) had statistically significant differences (P < 0.001) both in univariate analysis and a multivariate logistic regression model. The multivariate logistic regression model of area under curve (AUC) area of the receiver operating characteristic (ROC) curve was 0.931(sensitivity = 95.00%, specificity = 88.40%, log-rank test: P < 0.01), and the calibration curve indicated good prediction accuracy. The ROC analysis and Cox proportional hazards regression model revealed that the cutoff point of LPA was 50.95° (sensitivity = 95.00%, specificity = 72.09%, log-rank test: P < 0.05) and the cutoff point of CPA was 90.51° (sensitivity = 90.00%, specificity = 90.70%, log-rank test: P < 0.05). A nomogram plot to predict the risk of failure (C-index = 0.873, 95% CI: 0.785 to 0.961) and nomograms for predicting the survival probability at 1, 2 or 3 years whose calibration curves showed excellent prediction accuracy were available for the clinician. Preserved angles (PAs) are valuable in the prediction of prognosis in surgical treatment. The bone impaction grafting through femoral head-neck fenestration can achieve better clinical efficacy, especially for patients with LPA >50.95° and CPA >90.51°.

Trends in Surgical Management of Osteonecrosis of the Femoral Head: A 2010 to 2020 Nationwide Study

BACKGROUND

The incidence of osteonecrosis of the femoral head (ONFH) is estimated at more than 20,000 patients annually in the US. Our study aimed to provide a 10-year analysis: 1) evaluating total operative procedures with rates normalized to the population; 2) determining trends of arthroplasty versus joint-preserving procedures; and 3) quantifying specific operative techniques in patients <50 versus >50 years of age.

METHODS

A total of 64,739 patients who were diagnosed with ONFH and underwent hip surgery were identified from a nationwide database between 2010 and 2020. The percentage of patients managed by each operative procedure was calculated and normalized to the overall population annually. Patients were grouped into joint-preserving versus non-joint-preserving (arthroplasty) procedures, and divided by age under/over 50 years. Linear regression modeling was performed to evaluate trends/differences in procedural volume by year.

RESULTS

The number of operative procedures to treat ONFH has relatively declined from 2010 to 2020. The relative proportion of joint-preserving procedures increased (8.6% to 11.2%) during this time period. There were significantly more joint-preserving procedures in patients aged <50 years relative to >50 years (15.3% versus 2.7%, P < .001). Overall, THA was the most common procedure (57,033;88.1%) relative to hemiarthroplasty (3,875;6.0%), core decompression (2,730;4.2%), bone graft (467;0.7%), and osteotomy (257;0.4%).

CONCLUSION

Surgical management of patients who have ONFH remains predominantly arthroplasty procedures (94% overall). Our findings suggest an increase in joint-preserving procedures, particularly core decompression, in patients <50 years (15.3%). Our findings provide insight into surgical management trends for ONFH, and suggest opportunities for joint-preserving procedures.

Relative frequency of avascular necrosis of the hip as indication for primary Total Hip Arthroplasty in the USA vs. India

Introduction

Background: Primary total hip arthroplasty (THA) is performed for a variety of pathologies. Osteoarthritis (OA) is the most common indication for THA in the United States of America (USA). The study aims to establish the incidence of indications for THA in the USA as compared to India and to assess whether Avascular Necrosis (AVN) of the Hip is a more frequent indication for THA in India than in the USA.

Methods

The National Inpatient Sample database (USA) and two Indian databases (one national and one regional) were analyzed to identify all patients who underwent primary THA within the databases. The relative frequencies of each indication for THA were determined. The patients' demographics and risk factors for AVN of the hip were recorded and assessed. The data were then compared across the patients in the USA and the patients in India.

Results

225,061 primary THA patients were identified in the USA database and 20,288 in the Indian database. The proportion of primary THA performed for AVN in the American database (5.97%) was significantly lower than the proportion of THA performed for AVN in the Indian database (51.8%).

Conclusion

The relative frequency of AVN as an indication for THA is significantly higher in India than in the USA. It is important to recognize the differences in relative indications for THA between world populations, as outcomes after THA among Eastern populations of the world may not be equivalent to ones seen in their Western counterparts.

Zingerone attenuates Ti particle-induced inflammatory osteolysis by suppressing the NF-κB signaling pathway in osteoclasts

Aseptic loosening caused by inflammatory osteolysis is one of the most frequent and serious long-term complications after total joint arthroplasty (TJA). Development of a new therapeutic drug is required due to the lack of effective therapy and serious adverse effects. This study aimed to explore the pharmacological properties of zingerone (ZO) in attenuating osteoclast-mediated periprosthetic osteolysis and how ZO modulates osteoclastogenesis. The nontoxic concentration of ZO was clarified by the CCK-8 method. Then, we explored the efficacy of ZO on suppressing osteoclast differentiation, F-actin ring formation, bone resorption, and NF-κB luciferase activity in vitro as well as osteoprotection in vivo. Polymerase chain reaction and western blotting were applied to detect the underlying mechanisms involved in osteoclastogenesis. ZO showed an obvious inhibitory effect on osteoclastogenesis and bone resorption in a dose-dependent manner by mainly suppressing the activation of NF-κB signaling pathways. Furthermore, ZO administration successfully attenuated titanium (Ti) particle-stimulated periprosthetic osteolysis and osteoporosis by regulating osteoclast formation. Our findings demonstrated the pharmacological properties of ZO in inhibiting osteoclast formation and function by downregulation of NF-κB signaling activation. As a result, these findings could be expected to provide a novel reagent for regulating inflammatory osteolysis caused by prosthetic loosening.

Hip function in patients undergoing conservative treatment for osteonecrosis of the femoral head

PURPOSE

Once collapsed, osteonecrosis of the femoral head (ONFH) generally obtains collapse cessation naturally and surgical intervention can be avoided in the long term. This study aimed to investigate the process of hip function and secondary osteoarthritis changes in ONFH patients undergoing conservative treatment.

METHODS

We included 54 patients with symptomatic ONFH at the first visit with a minimum follow-up of three years with conservative treatment. Patients were divided into two groups based on collapse cessation < 3 mm (stable group) or progression to > 3 mm (progression group). Additionally, we investigated age, sex, body mass index (BMI), etiology, contralateral side hip joint, the Japanese Investigation Committee (JIC) type classification, Harris hip score (HHS), Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire (JHEQ), and survival rate with secondary osteoarthritis as the endpoint.

RESULTS

The stable and progression groups had 31 and 23 patients, respectively. No significant differences in age, sex, BMI, and aetiology were observed between the two groups, except for the contralateral side hip joint and JIC type classification. The HHS and JHEQ were significantly improved at the final follow-up than at the first visit in the stable group. However, there were no significant differences in HHS and JHEQ at the final follow-up than at the first visit in the progression group. The five year survival rates with secondary osteoarthritis as the endpoint were significantly higher in the stable group (100%) than in the progression group (32.5%).

CONCLUSION

Hip joint function improved by continuing conservative treatment in ONFH patients with collapse cessation < 3 mm.

Evaluation of the predictive values of collapse and necrotic lesion boundary for osteonecrosis of the femoral head prognosis

OBJECTIVE

Osteonecrosis of the femoral head (ONFH) is a disabling and intractable orthopedic disease largely affecting young and middle-aged groups. Current standard of treatment relies on the collapse of femoral head as a predictor for prognosis. However, a wide range of variability in repair potentials is observed in patients with femoral head collapse. Therefore, the present study aimed to evaluate the accuracy of femoral head collapse as a predictor and to propose the necrotic lesion boundary as a novel yet reliable measure for ONFH prognosis.

METHODS

A retrospective cross-sectional study was conducted at the First Affiliated Hospital of Guangzhou University of Chinese Medicine, 203 hips with ONFH from 134 patients were included. The occurrences and progression of femoral head collapse were recorded. Necrosis lesion boundary was quantified and classified for each case based on anteroposterior view intact ratio (APIR) and the frog-leg view intact ratio (FLIR) as independent variables. Dependent variables were defined as progressive collapse or terminal collapse for Association Research Circulation Osseous (ARCO) stage II and III respectively. Logistic regression analysis, Receiver Operating Characteristic (ROC) curve and Kaplan-Meier (K-M) survival analysis was performed and results were interpreted.

RESULTS

Out of the 106 hips in ARCO stage II, 31 hips collapsed with further progression, while 75 hips had no collapse or collapse with repair of the necrotic areas. Out of the 97 hips in ARCO stage IIIA, the collapse continued to progress in 58 hips while the necrotic areas were repaired in 39 hips. Logistic regression analysis demonstrated that both APIR and FLIR, were independent risk factors. Further ROC curve analysis indicated that the cutoff values of APIR and FLIR could be considered as indications for evaluating the prognosis of ONFH. Contrary to the traditional view of poor prognosis after femoral head collapse, K-M survival analysis demonstrated a high value of APIR and FLIR for ONFH prognosis.

CONCLUSION

The present study found that the occurrence of collapse is an oversimplified predictor for ONFH prognosis. The collapse of the femoral head in ONFH does not predict a poor prognosis. The necrosis lesion boundary has a high value in predicting ONFH prognosis and informing clinical treatment strategies.

Osteoclasts: Other functions

Osteoclasts are the only cells that can efficiently resorb bone. They do so by sealing themselves on to bone and removing the mineral and organic components. Osteoclasts are essential for bone homeostasis and are involved in the development of diseases associated with decreased bone mass, like osteoporosis, or abnormal bone turnover, like Paget's disease of bone. In addition, compromise of their development or resorbing machinery is pathogenic in multiple types of osteopetrosis. However, osteoclasts also have functions other than bone resorption. Like cells of the innate immune system, they are derived from myeloid precursors and retain multiple immune cell properties. In addition, there is now strong evidence that osteoclasts regulate osteoblasts through a process known as coupling, which coordinates rates of bone resorption and bone formation during bone remodeling. In this article we review the non-resorbing functions of osteoclasts and highlight their importance in health and disease.

Total Hip Arthroplasty via direct anterior approach for osteonecrosis; comparison with primary hip osteoarthritis in a mid term follow up

BACKGROUND

To determine the mid-term outcomes of conventional cementless Total Hip Arthroplasty (THA) in patients with avascular necrosis (AVN) of the femoral head and compare to patients with primary hip osteoarthritis (OA).

METHOD

A total of 330 consecutive primary THA procedures (AVN and OA) performed between 2010 and 2013 by a single surgeon and in a single center using the direct anterior approach (DAA) were included. Assessments including SF-36, WOMAC, and Harris Hip Scores (HHS) were retrieved from patients before the surgery and at the latest follow-up. Clinical and functional outcomes were compared between the AVN and OA groups.

RESULTS

A total of 294 consecutive THA (AVN = 107, OA = 187) with 104.4 ± 6.2 months follow-up were analyzed, which AVN patients were significantly younger (32.0 vs. 59.6 y/o). Corticosteroid 34 (31.8%), idiopathic AVN 31 (29.0%) and use of unapproved weight gain supplements (UWGS) 23 (21.5%) were the main reasons for AVN. Despite that preoperative scores were comparable (P > 0.05), the HHS, SF-36, and WOMAC scores are significantly higher in the AVN group after THA surgery (P < 0.05). Moreover, flexion and abduction ROM were significantly higher in the AVN group (P < 0.05). Regarding each complication, no significant difference was observed between groups. In the whole sample, there were 5 (1.7%) revisions due to loosening of acetabular components, all the OA group (P > 0.05).

CONCLUSION

Conventional cementless THA with highly cross-linked polyethylene provides satisfactory mid-term results in patients with AVN with a low rate of postoperative complications. Compared to primary OA patients, this group reaches superior postoperative scores.

[Short hip stem for THA in avascular necrosis of the femoral head]

INTRODUCTION

Osteonecrosis of the femoral head or avascular necrosis of the femoral head (HKN) is a complex disease that, without treatment, leads to infraction of the femoral head in most cases. In these cases, only replacement of the hip joint will help, although there is no clear recommendation of an arthroplasty type. In the last two decades, the treatment of primary and secondary coxarthrosis with short-shaft prostheses with different anchoring philosophies has increased. Since short-shaft fitting is a possible option especially in younger patients, the question arises about possible fittings of advanced HKN with these stem types, especially with metaphyseal anchorage. The aim of this study was to review the existing literature on the results of short stem prosthesis in HKN and to present the advantages and disadvantages of short stem prosthesis in osteonecrosis of the femoral head.

MATERIAL AND METHODS

This review analyzes the existing studies on short stem arthroplasty for HKN.

RESULTS

Only a few studies exist that have analyzed clinical and radiologic outcomes of short stem replacement in HKN.

CONCLUSION

The existing short- and medium-term results show mostly good outcomes. However, it is difficult to draw a general conclusion due to differences in stem design and fixation. Short stems with primary diaphyseal fixation do not show an increased risk of failed osseointegration or loosening. Constructions with primary metaphyseal fixation should undergo MRI to rule out the possibility of necrosis extending beyond the femoral neck.

Effect of trochanter displacement on impingement and bone contact in total hip arthroplasty performed after curved intertrochanteric varus osteotomy for osteonecrosis of the femoral head: a simulation study

Background

Curved intertrochanteric varus osteotomy (CVO) is a useful treatment option for osteonecrosis of the femoral head (ONFH). However, the effect of proximal femoral deformity in cases of CVO converted to total hip arthroplasty (THA) remains unclear. The aim of this study was to evaluate the effect of trochanter displacement on impingement and the contact state of the implant and femur in THA.

Methods

Thirty-eight hips that had undergone CVO for ONFH were reviewed and compared with a control group of 30 contralateral hips that had not undergone surgery. The range of motion (ROM) and impingement patterns and the percentage of cortical bone in the stem placement within the femur were measured by simulation using CT-based three-dimensional template software. We also measured the ROM and the number of joints that achieved the ROM required for activities of daily living when the upward displaced apex of the greater trochanter with osteotomy was resected and compared the findings with those obtained when the apex was not resected.

Results

The CVO group showed a significantly greater bony impingement in external rotation (68.4% vs. 43.3%, p = 0.033) and abduction (78.9% vs. 33.3%, p < 0.001) than in the control group. The CVO group showed a significantly smaller range of external rotation (19.0° [interquartile range; 4.0–28.8] vs. 38.0° [interquartile range; 36.0–41.8], p < 0.001) and abduction (23.0° [interquartile range; 8.5–38.8] vs. 56.0° [interquartile range; 50.3–60.0], p < 0.001) than in the control group. Significantly more joints achieved the ROM necessary for activities of daily living when the apex was resected than when it was not (10.5% vs. 63.2%, p < 0.001). The percentage of cortical bone in the stem placement position was significantly higher in the CVO group than in the control group in the proximal portion of the stem (25.5% vs. 0.0%, p < 0.001).

Conclusion

In cases requiring conversion to THA, we recommend resecting the upward displaced apex to achieve a sufficient ROM and carefully resecting the bone to avoid malignment of the stem.

Influence of less invasive hip preservation surgery on subsequent hip arthroplasty for osteonecrosis of the femoral head

The purpose of this study was to evaluate the outcomes of total hip arthroplasty (THA) following less invasive hip-preserving procedures (LIHPs) and present a critical overview of the literature to aid in better result interpretation. The search time was from the establishment of the database to September 2021, and the outcome indicators were extracted and analyzed by Cochrane Collaboration Review Manager software (RevMan version 5.4). Finally, 10 articles were included in this meta-analysis by searching Chinese databases and English databases. Three of them were published in Chinese, and the remaining studies were published in English. LIHP was further divided into the tantalum rod implantation group and the non-tantalum rod implantation group. The results showed that prior tantalum rod implantation increased the difficulty of conversion to THA, which was reflected mainly in the longer operative time [weighted mean difference (WMD) = 24.50, 95% confidence interval (CI) = 14.09–34.91, P < 0.00001] and greater intraoperative blood loss (WMD = 114.74, 95% CI = 33.52–195.96, P = 0.006), while no significant difference was found between the non-tantalum rod implantation group and the control group. Simultaneously, easier intraoperative fracture [odds ratio (OR) = 5.88, 95% CI = 0.93–37.05, P = 0.06] and stem malalignment (OR = 4.17, 95% CI = 1.18–14.71, P = 0.03) in the LIHP group tended to be observed than in the control THA group. However, there was no significant difference in cup anteversion and inclination angle, ectopic ossification, postoperative Harris Hip Score and survivorship between the LIHP group and the control group. Although LIHP increased the difficulty of the conversion to THA, it does not detrimentally affect the clinical results of subsequent THA in the mid-term follow-up.

Animal Models of Femur Head Necrosis for Tissue Engineering and Biomaterials Research

Femur head necrosis, also known as osteonecrosis of the femoral head (ONFH), is a widespread disabling pathology mostly affecting young and middle-aged population and one of the major causes of total hip arthroplasty in the elderly. Currently, there are limited number of different clinical or medication options for the treatment or the reversal of progressive ONFH, but their clinical outcomes are neither satisfactory nor consistent. In pursuit of more reliable therapeutic strategies for ONFH, including recently emerged tissue engineering and biomaterials approaches, in vivo animal models are extremely important for therapeutic efficacy evaluation and mechanistic exploration. Based on the better understanding of pathogenesis of ONFH, animal modeling method has evolved into three major routes, including steroid-, alcohol-, and injury/trauma-induced osteonecrosis, respectively. There is no consensus yet on a standardized ONFH animal model for tissue engineering and biomaterial research; therefore, appropriate animal modeling method should be carefully selected depending on research purposes and scientific hypotheses. In this work, mainstream types of ONFH animal model and their modeling techniques are summarized, showing both merits and demerits for each. In addition, current studies and experimental techniques of evaluating therapeutic efficacy on the treatment of ONFH using animal models are also summarized, along with discussions on future directions related to tissue engineering and biomaterial research. Impact statement Exploration of tissue engineering and biomaterial-based therapeutic strategy for the treatment of femur head necrosis is important since there are limited options available with satisfactory clinical outcomes. To promote the translation of these technologies from benchwork to bedside, animal model should be carefully selected to provide reliable results and clinical outcome prediction. Therefore, osteonecrosis of the femoral head animal modeling methods as well as associated tissue engineering and biomaterial research are overviewed and discussed in this work, as an attempt to provide guidance for model selection and optimization in tissue engineering and biomaterial translational studies.

The Role of Structural Deterioration and Biomechanical Changes of the Necrotic Lesion in Collapse Mechanism of Osteonecrosis of the Femoral Head

Osteonecrosis of the femoral head (ONFH) is a crippling disease which is due to a lack of effective therapeutic measures. Its natural progression is rapid, the internal bone structure of the femoral head changes dramatically, and the subsequent fractures and collapse cause severe hip pain and loss of hip function. Femoral head collapse is a critical turning point in the development of ONFH and is related to the prognosis of patients. Early prevention and intervention help to preserve the hip joint and delay femoral head collapse. However, the mechanism of collapse still needs to be further studied because it is affected by different complex factors. This review discusses the underlying causes of femoral head collapse from two aspects: structural degradation and regional changes of biomechanical properties in the necrotic femoral head.

Hip Arthroscopy and Core Decompression for Avascular Necrosis of the Femoral Head Using a Specific Aiming Guide: A Step-by-Step Surgical Technique

Avascular necrosis of the femoral (AVN) head is a disabling disease that affects function, mobility, and quality of life in the young adult. Its pathology involves blood circulation disruption of the femoral head and subchondral infarction. This leads to cartilage thinning, femoral head depression, and cartilage breakage, which results in hip osteoarthritis. In the past decade the prevalence of intraarticular pathology has been almost 95%, this revealed with hip arthroscopy (HA). HA and core decompression (CD) of the femoral head can be used effectively and concomitantly to treat AVN with excellent results, HA allows for excellent visualization of the hip joint cartilage, allowing treatment of femoroacetabular impingement syndrome (FAIS) and intra-articular pathology. Our technique demonstrates that retrograde core decompression with allograft and mixed bone matrix is an excellent choice of treatment in the early stages of AVN/ONFH. The femoral head-specific aiming guide is very reliable, is simple to use arthroscopically if placed in the posterolateral portal of the hip, and offers exact pin placement at the necrotic site, as well as less operative time and less radiation to the patient and surgical team.

Concentric Circle Technique for Assessment of Femoral Head Deficiency in Osteonecrosis of Femoral Head

Introduction

There is a lack of standardized objective tools to assess collapse for osteonecrosis of the femoral head (ONFH) patients’ follow-up. We describe a quantitative technique of collapse assessment using a superimposed concentric circular ring matching the intact part of the femoral head in anteroposterior (AP) radiographs.

Methods

We retrospectively analyzed 30 normal femoral heads and 30 ONFH (15 pre-collapse,15 post-collapse) in anteroposterior hip radiographs. A best-fitting circle was superimposed on articular margins of the femoral head and the maximum width of the deficient zone of the femoral head (not matching the circle) was measured. The width (pW) was measured as percentage-width in proportion to the circle’s diameter. The findings were compared among normal and ONFH radiographs. Intraclass correlation coefficients were calculated for intraobserver and interobserver reliability of the measurements.

Results

The mean femoral head deficiencies predicted by pW were 0.2±0.5% for normal hip, 2.8±1.1% for pre-collapse, and 8.9±3.8% for post-collapse radiographs. We observed significant differences in the measurements of pW among the control group, pre-collapse and post-collapse groups. Interobserver and intraobserver reliabilities for the measurements were high.

Conclusion

The described concentric circle technique is a simple and reliable method for objective assessment of subtle alterations in the sphericity of the femoral head and can be helpful for the radiographic follow-up of ONFH patients.

Risk factors for multi-joint disease in patients with glucocorticoid-induced osteonecrosis

This study investigated risk factors for osteonecrosis involving multiple joints (MJON) among glucocorticoid-treated patients. The best predictor of MJON was cumulative oral glucocorticoid dose. Risk of MJON was 12-fold higher in patients who had a second risk factor for osteonecrosis. Further research is needed into strategies for prevention of MJON.

INTRODUCTION

Osteonecrosis (ON) is a debilitating musculoskeletal condition in which bone cell death can lead to mechanical failure. When multiple joints are affected, pain and disability are compounded. Glucocorticoid treatment is one of the most common predisposing factors for ON. This study investigated risk factors for ON involving multiple joints (MJON) among glucocorticoid-treated patients.

METHODS

Fifty-five adults with glucocorticoid-induced ON were prospectively enrolled. MJON was defined as ON in ≥ three joints. Route, dose, duration, and timing of glucocorticoid treatment were assessed.

RESULTS

Mean age of enrolled subjects was 44 years, 58% were women. Half had underlying conditions associated with increased ON risk: systemic lupus erythematosus (29%), acute lymphoblastic leukemia (11%), HIV (9%), and alcohol use (4%). Mean daily oral dose of glucocorticoids was 29 mg. Average cumulative oral dose was 30 g over 5 years. The best predictor of MJON was cumulative oral glucocorticoid dose. For each increase of 1,000 mg, risk of MJON increased by 3.2% (95% CI 1.03, 1.67). Glucocorticoid exposure in the first 6 months of therapy, peak dose (oral or IV), and mean daily dose did not independently increase risk of MJON. The risk of MJON was 12-fold in patients who had a second risk factor (95% CI 3.2, 44.4).

CONCLUSIONS

Among patients with glucocorticoid-induced ON, cumulative oral dose was the best predictor of multi-joint disease; initial doses of IV and oral glucocorticoids did not independently increase risk. Further research is needed to better define optimal strategies for prevention and treatment of MJON.

Autologous stem cell implantation with core decompression for avascular necrosis of the femoral head using a new device

INTRODUCTION

Autologous stem cell progenitor implantation into necrotic lesions of the femoral head has previously been described as a potential treatment for avascular necrosis (AVN), on the basis that there is a reduced number of functioning stem cells in the marrow within the necrotic segment. We present a case series of patients with AVN that underwent core decompression with autologous stem cell implantation using a new device.

METHODS

The records and imaging of patients with AVN of the femoral head treated by a single surgeon were retrospectively reviewed. All patients were treated with core decompression and stem cell progenitor implantation, using the PerFuse system. Preoperatively, demographic information, AVN staging (as per Ficat and Arlet classification) and visual analogue pain scores (VAS) of the hips were recorded. These results were compared with postoperative VAS and imaging, with further review on the progression of AVN.

RESULTS

We treated 14 hips in 13 patients with an average follow up of 12 months. Patients with Ficat I-II were selected for the procedure. The average preoperative VAS was 3.9. Postoperatively, this dropped to 2.6, with over half of patients reporting at least a two-point decrease in pain. Eight of the 14 treated hips showed no radiological progression of the disease, while six showed femoral head collapse requiring total hip arthroplasty (THA) at an average of ten months after treatment.

CONCLUSION

Our early findings indicate that hip decompression with stem cell progenitor implantation for AVN of the femoral head provides symptomatic relief and may be beneficial in arresting progression of disease using this simple new device.

Idiopathic arteriopathy-induced focal osteonecrosis of the femoral head in a young dog

CASE DESCRIPTION

A 15-month-old 6.5-kg (14.3-lb) castrated male mixed-breed dog was evaluated because of a 4-month history of progressive intermittent non-weight-bearing lameness of the left pelvic limb.

CLINICAL FINDINGS

Orthogonal radiography of the hip joints revealed a 4-mm atypical radiolucent lesion on the distal caudomedial aspect of the left femoral head and a disproportionately large-diameter femoral medullary canal with a low canal flare index. Prolonged unresponsiveness to medical management and progressive enlargement of the lesion prompted the recommendation for total hip replacement (THR).

TREATMENT AND OUTCOME

THR was performed to restore pain-free function of the left pelvic limb and normal activity. A circular osteochondral flap was grossly evident on the femoral head. Histopathologic findings for this portion of the bone indicated an arteriopathy-induced focal subchondral osteonecrosis that had resulted in articular surface collapse. The noted idiopathic arteriopathy had disrupted the normal blood supply to the affected area. On reexamination and radiographic evaluation 13 months after THR, the dog appeared to have pain-free function of the affected limb and had returned to normal activity with no reported complications or problems.

CLINICAL RELEVANCE

To the authors' knowledge, this report represented the first description of arteriopathy-induced focal osteonecrosis of the caudomedial aspect of the femoral head and its successful treatment in a young dog. This type of lesion may more commonly be the cause of hip joint osteoarthritis in young dogs than previously recognized because establishing a definitive diagnosis requires early recognition and histologic evaluation before advanced degenerative changes develop that obscure the underlying etiology.

Epidemiological Study Based on China Osteonecrosis of the Femoral Head Database

Objective

The aim of the present study was to reveal the case characteristics of osteonecrosis of the femoral head (ONFH) in Mainland China.

Methods

This cross‐sectional epidemiological study derived data for ONFH patients from July 2016 to December 2018 from the China Osteonecrosis of the Femoral Head Database (CONFHD). The derived data included gender, age, body mass index (BMI), height, occupation, region, and etiology of femoral head necrosis. A descriptive analysis was performed to summarize the epidemiological characteristics of the case data in the CONFHD.

Results

A total of 1844 ONFH patients (2945 hips) were included in this study, comprising 1302 men and 542 women. The age of patients ranged from 18 to 95 years, with a median of 50 years, and the male to female ratio was 2.4. Male patients are younger than female patients (48.26 ± 12.56 years old and 55.56 ± 14.94 years old, respectively). Among the 1844 patients (2945 hips), there were 528 (17.92%) hips at ARCO stage I, 941 (31.99%) hips at ARCO stage II, 873 (29.63%) hips at ARCO stage III, and 603 (20.46%) hips at ARCO stage IV. In the subclassification of ARCO stages I and II, the majority of cases were type C; type A comprised the majority in the subclassification of ARCO stage III. According to the Kellgren–Lawrence classification system, among the 603 ARCO stage IV hips, there were 178 (29.52%) grade 1 hips, 201 (33.34%) grade 2 hips, 176 (29.18%) grade 3 hips, and 48 (7.96%) grade 4 hips. Most were from three provinces: Henan (27.3%), Shanxi (13.9%), and Shandong (11.9%). Regarding BMI, 982 patients (53.25%) were overweight or obese. Among all patients, the largest proportion of patients engaged in level IV manual work. Of all the patients, there were 495 (26.84%) with steroid‐induced ONFH, 685 (37.15%) were alcoholics, and 290 (15.73%) had traumatic ONFH. The 495 patients with steroid‐induced ONFH included 278 men (56.16%) and 217 women (43.84 %), had a complete history of hormone use. Among the primary diseases, there were 195 cases (39.39%) of immune system diseases, followed by dermatological diseases, respiratory diseases, nephropathy, and other diseases. There were a total of 685 patients with alcoholic ONFH, 589 of these patients (85.99%) were men. A total of 188 (27.45%) patients had drunk alcohol for 6–10 years (comprising the highest proportion), and 280 patients (40.88%) consumed 3001–3500 mL of alcohol each week (the highest proportion).

Conclusion

Osteonecrosis of the femoral head most commonly occurs after the age of 40. Male patients have an earlier onset than female patients, and the number of male patients is approximately twice that of female patients. The BMI of patients was mainly in the overweight and obese range, and half of these patients engaged in level IV manual work. From the imaging findings, the numbers of hips at ARCO stages II and III were greatest, and the number at stage I was relatively small. Among all the causes of disease, alcohol, steroid use and trauma were the three most common reasons for ONFH.

Augmentation of core decompression with synthetic bone graft does not improve mechanical properties of the proximal femur

Core decompression is a minimally invasive surgical technique used to treat patients with avascular necrosis of the femoral head. The procedure requires an entry hole in the lateral cortex of the femur which potentially leaves patients susceptible to subtrochanteric fractures. The purpose of this study was to determine if filling the core decompression tract with synthetic bone-graft mechanically strengthens the proximal femur. Twenty composite synthetic femurs underwent a core decompression procedure; ten were augmented with synthetic bone-graft (PRO-DENSE™, Wright Medical) and ten femurs were left unfilled as a control group. Compressive testing to failure was performed using a mechanical testing machine. Stiffness, fracture load, and toughness did not significantly differ between groups. More subtrochanteric fractures were seen in the control group (6 of 10 specimens) compared to the bone-graft augmented group (2 of 10 specimens). In conclusion, augmentation of a core decompression tract does not improve mechanical properties in a synthetic bone model but may be protective of subtrochanteric fracture.

Does prior core decompression have detrimental effect on subsequent total hip arthroplasty for osteonecrosis of the femoral head: A systematic review and meta-analysis

BACKGROUND

Core decompression (CD) is effective in relieving pain and delaying the progression to total hip arthroplasty (THA) for osteonecrosis of the femoral head (ONFH). However, the influence of CD on subsequent THA has not yet been established. Therefore, we performed this systematic review to answer: does prior CD have detrimental effect on subsequent THA for ONFH, especially with regards to survivorship and functional results, as well as perioperative and postoperative complications.

PATIENTS AND METHODS

After registration on PROSPERO (CRD42019118861), literature published up to and including November 2018 was searched in the PubMed, Embase and Cochrane library databases with predetermined terms. Comparative studies on the clinical outcomes between conversion to THA with prior CD (the Prior CD group) and primary THA (the Control group) for ONFH were included. The outcomes of interest included survivorship free from revision, the postoperative functional performance, perioperative and postoperative complications. Data was extracted systematically and a meta-analysis was performed.

RESULTS

Overall, 5 retrospective cohort studies with 110 hips were identified for the Prior CD group and 237 hips were identified for inclusion in the Control group. All of the studies were of high quality in terms of the Newcastle-Ottawa Scale. No difference in the rate of revision between the two groups (2/42 (4.8%) vs. 4/160 (2.5%); RR=1.92; 95% CI=0.34 to 10.75; p=0.46) was detected after a minimum two-year follow-up. The mean postoperative Harris Hip Score was similar between the two groups in all 5 studies. The two groups experienced similar blood loss (Mean difference=12.17ml; 95% CI= -15.28 to 39.61ml; p=0.38). Moreover, intraoperative fracture was increased in the Prior CD group, though this did not reach statistical significance (3/31 (9.7%) vs. 0/55 (0.0%); RR=7.05; 95% CI=0.82 to 60.78; p=0.08). Similarly, osteolysis or radiolucent lines were more likely to occur in the Prior CD group without statistical significance (9/81 (11.1%) vs. 6/200 (3.0%); RR=3.14, 95% CI=0.98 to 10.06; p=0.05).

DISCUSSION

The present evidence indicated that prior CD does not detrimentally affect the survivorship nor hip scores of subsequent THA. Attention should be paid, however, to the potential for intraoperative fracture, postoperative osteolysis or radiolucent lines.

LEVEL OF EVIDENCE

III; systematic review and meta-analysis of level III retrospective comparative studies.

Dynamic evolution of osseous structure in osteonecrosis of the femoral head and dynamic collapse risks: a preliminary CT image study

Background

Collapse risk of osteonecrosis of the femoral head (ONFH) is estimated mainly based on static indicators, including lesion size and lesion location, but bone repairing is a dynamic process that lasts for years. The present study attempted to analyze the dynamic evolution of the osseous structure and its correlation with radiographic progression.

Methods

This retrospective study included 50 hips with ONFH from 50 patients. Participants were divided into the non-collapse group (n = 25) and the collapse group (n = 25). Original files of the initial computed tomography (CT) images were imported into imaging processing software for morphology analysis. The volume of sclerotic bone, the volume of soft tissue, and bone mineral density (BMD) were calculated. The linear correlations between the aforementioned indicators and the disease duration were estimated. The logistic regression analysis was conducted to evaluate the correlation of these indicators with the radiographic progression. Receiver operating characteristic (ROC) analysis was used to evaluate these indicators’ prediction performance.

Results

The volume of sclerotic bone and the BMD grew with disease duration, but the volume of soft tissue decrease. The logistic regression analysis found that the volume of sclerotic bone and the BMD were statistically associated with radiographic progression. The ROC analysis found that the regression model, which integrated the volume of sclerotic bone and the BMD, had satisfactory performance in predicting radiographic progression.

Conclusion

The present study suggested a dynamic evolution of the osseous structure and a dynamic variation trend of the collapse risk in ONFH. The volume of sclerotic bone and the BMD might serve as further prognostic indicators when estimating the collapse risk.

Exploring the Risk Factors for the Misdiagnosis of Osteonecrosis of Femoral Head: A Case-Control Study

Objective

The purpose of the present study was to evaluate the present situation and risk factors for the misdiagnosis of osteonecrosis of femoral head (ONFH), providing the basis for accurate diagnosis of ONFH.

Methods

For this retrospective study, 1471 patients with ONFH were selected from the China Osteonecrosis of Femoral Head Database (CONFHD). These patients had been recruited between July 2016 and December 2018. According to whether or not they were misdiagnosed, the patients were divided into two groups, with 1168 cases (22–84 years old) included in the diagnosis group and 303 cases (21–80 years old) in the misdiagnosis group. Misdiagnosis was measured using the following criteria: (i) the patient had the same symptoms and signs, and the second diagnosis was not consistent with the initial diagnosis within 6 months; and (ii) the patient was admitted to a hospital participating in CONFHD and the previous diagnosis was inconsistent with the diagnosis given by the expert group. Comparisons of age, visual analogue scale for pain, and body mass index between the two groups were performed using a t‐test. Gender, causes of ONFH, primary diseases requiring corticosteroids, methods of corticosteroid use, corticosteroid species, type of trauma, onset side of the disease, pain side, whether symptoms are hidden, and type of imaging examination at the initial visit were compared using the χ²‐test. Years of alcohol consumption, weekly alcohol consumption, and physician title at the initial visit were compared using a Mann–Whitney U‐test. Furthermore, the statistically significant factors were evaluated using multiple regression analysis to investigate the risk factors of misdiagnosis.

Results

A total of 303 patients (20.6%) were misdiagnosed: 118 cases were misdiagnosed as lumbar disc herniation, 86 cases as hip synovitis, 48 cases as hip osteoarthritis, 32 cases as rheumatoid arthritis, 11 cases as piriformis syndrome, 5 cases as sciatica, and 3 cases as soft‐tissue injury. Whether symptoms are hidden (P = 0.038, odds ratio [OR] = 1.546, 95% confidence interval [CI] = 1.025–2.332), physician title at the initial visit (P < 0.001, OR = 3.324, 95% CI = 1.850–5.972), X‐ray examination (P < 0.001, OR = 4.742, 95% CI = 3.159–7.118), corticosteroids (P < 0.001, OR = 0.295, 95% CI = 0.163–0.534), alcohol (P < 0.001, OR = 0.305, 95% CI = 0.171–0.546), and magnetic resonance imaging (MRI) examination (P = 0.042, OR = 0.649, 95% CI = 0.427–0.985) were each found to be associated with misdiagnosis.

Conclusion

Osteonecrosis of the femoral head is easily misdiagnosed as lumbar disc herniation, hip synovitis, hip osteoarthritis, and rheumatoid arthritis. Patient history of corticosteroid use or alcohol abuse and MRI examination at the initial diagnosis may be protective factors for misdiagnosis. Hidden symptoms, physician title at the initial visit (as attending doctor or resident doctor), and only X‐ray examination at the initial diagnosis may be risk factors for misdiagnosis.

The combination of PLLA/PLGA/PCL composite scaffolds integrated with BMP-2-loaded microspheres and low-intensity pulsed ultrasound alleviates steroid-induced osteonecrosis of the femoral head

Low-intensity pulsed ultrasound (LIPUS), which has been previously reported to promote bone repair, is proposed to be a noninvasive form of therapy for the treatment of osteonecrosis. Bone fillers made from composite scaffolds have been demonstrated to be effective for preventing bone defects such as osteonecrosis. The present study aimed to investigate whether the application of LIPUS combined with bone morphogenetic protein-2 (BMP-2)-loaded poly-L-lactic acid/polylactic-co-glycolic acid/poly-ε-caprolactone (PLLA/PLGA/PCL) composite scaffolds can improve recovery in a rat model of steroid-induced osteonecrosis of the femoral head (ONFH). BMP-2-loaded PLGA microspheres incorporated into PLLA/PLGA/PCL composite scaffolds were constructed. Bilateral femoral head LIPUS intervention was conducted in rats with steroid-induced ONFH. LIPUS intervention alone contributed to the alleviation of osteonecrosis, in addition to improving load-carrying capacity and accelerated bone formation, angiogenesis and differentiation. Subsequently, femoral head parameters and assessment of load-carrying capacity, bone formation-related factors, and angiogenesis- and differentiation-related factors were measured in rats with or without implanted BMP-2-loaded PLLA/PLGA/PCL composite scaffolds. LIPUS combined with the implantation of PLLA/PLGA/PCL composite scaffolds loaded with BMP-2 microspheres protected rats against steroid-induced ONFH and improved load-carrying capacity, bone formation, angiogenesis and differentiation. Together, these data support the use of BMP-2-loaded PLLA/PLGA/PCL composite scaffolds combined with LIPUS for ONFH as a potential alternative curative solution for treating bone diseases.

Diagnosis of Osteonecrosis of the Femoral Head: Too Little, Too Late, and Independent of Etiology

BACKGROUND

Joint preservation is more effective in early-stage osteonecrosis of the femoral head (ONFH); thus, prompt diagnosis when the femoral head is still salvageable is important. We report a 20-year retrospective study that summarizes age at presentation, etiology, and Association Research Circulation Osseous stage at diagnosis.

METHODS

Our database was reviewed to identify patients younger than 65 years of age who were diagnosed with atraumatic ONFH between 1998 and 2018. Demographic characteristics of patients were evaluated and categorized into different subgroups.

RESULTS

Four hundred thirteen patients were identified. At initial presentation, 23% were diagnosed with early-stage ONFH, while 77% were diagnosed with late-stage ONFH. Forty-nine percent had a history of corticosteroid use, of which 13% were diagnosed with hematologic malignancy and 8% were diagnosed with lupus. Ethanol abuse, idiopathic, sickle cell disease, and human immunodeficiency virus were present in 11%, 30%, 3%, and 3%, respectively. The mean age of patients with corticosteroid use (40 ± 14 years) was significantly younger than ethanol use (46 ± 11 years, P = .014) and idiopathic causes (48 ± 11 years, P < .001), but significantly older than sickle cell disease (32 ± 11 years, P = .031). There was no difference in the age of presentation for early-stage and late-stage ONFH by etiology.

CONCLUSION

Nearly 80% of the patients presented with late-stage ONFH. Hence, we have a narrow window of opportunity for hip preservation surgery before femoral head collapse. A multidisciplinary approach to improve screening awareness for early detection by focusing on the etiologic identification and patient education might reduce the incidence of hip arthroplasty in young patients.

Thirty-Day Complications in Osteonecrosis Patients Following Total Hip Arthroplasty

BACKGROUND

Thirty-day complications in osteonecrosis (ON) patients undergoing total hip arthroplasty (THA) are inconsistently reported. Therefore, the purpose of this study is to evaluate (1) the incidence of THA, (2) operative times, (2) length of stay, (3) reoperation rates, (4) readmission rates, and (5) complication rates, in the general vs ON THA populations. We also substratified and compared these cohorts based on ON-specific risk factors.

METHODS

Using the National Surgical Quality Improvement Program database, Current Procedural Terminology code 27130, International Classification of Disease, Ninth Edition code 733.42, and a 1:1 propensity score match, a total of 8344 matched ON and non-ON THA patients were identified. ON patients were also substratified based on key risk factors. The above variables were compared between the matched ON and non-ON cohorts as well as for patients with each risk factor using Pearson's chi-square and Student t-tests.

RESULTS

The proportion of THAs performed on ON patients decreased by 35% from 2008 to 2015. Mean operative times were constant between the ON and non-ON patients (102 minutes). ON patients had shorter mean length of stay (3.1 vs 3.4 days, P = .002). Of the 17 different 30-day complications evaluated, superficial surgical site infection (1.2% vs 0.6%, P = .004), pneumonia (0.8% vs 0.2%, P = .001), transfusion (15.6% vs 5.4%, P < .001), and readmission (5.1% vs 2.3%, P = .012) were higher among ON patients. ON patients with a history of corticosteroid use, higher American Society of Anesthesiologists score, and smoking were also found to have higher complication rates compared to non-ON patients with the same risk factors.

CONCLUSION

This is one of the first studies to compare postoperative THA outcomes between matched ON vs non-ON patients, while also taking into consideration specific risk factors between the cohorts.

Curved Intertrochanteric Varus Osteotomy vs Total Hip Arthroplasty for Osteonecrosis of the Femoral Head in Patients Under 50 Years Old

BACKGROUND

Given recent advances in total hip arthroplasty (THA), curved intertrochanteric varus osteotomy (CVO) is not indicated as a treatment for osteonecrosis of the femoral head (ONFH), unless indicated to maintain long-term hip function and achieve patient satisfaction. We aimed to compare the clinical outcomes of CVO with those of THA for treatment of ONFH in young adults <50 years old.

METHODS

This comparative study included 105 ONFH patients: 59 patients (65 hips) who underwent CVO and 46 patients (56 hips) who underwent THA. Assessment tools included the Harris hip score (HHS), patient-reported outcomes of the Short Form-36, Oxford hip score, Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire, and University of California, Los Angeles score, together with complication and survival rates.

RESULTS

Preoperative HHS was significantly higher in the CVO group than in the THA group (P < .01). At the last follow-up, no between-group differences were noted in HHS, all domains of Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire scores, Oxford hip score, and Short Form-36. University of California, Los Angeles scores and complication rates were comparable: 3% for the CVO and 7% for the THA group. The 10-year survival rate with surgery for any reason as the end point was comparable, at 91.8% for the CVO and 97.7% for the THA group.

CONCLUSION

Functional outcomes, survival rate, and sporting activities for patients <50 years old undergoing CVO or THA for ONFH were comparable after a mean follow-up period of 10 years. Strict indications for CVO can help maintain hip function and patient satisfaction equivalent to that for THA, in the long term.

Prediction of Collapse Using Patient-Specific Finite Element Analysis of Osteonecrosis of the Femoral Head

Objective

To develop a prediction method for femoral head collapse by using patient‐specific finite element analysis of osteonecrosis of the femoral head (ONFH).

Methods

The retrospective study recruited 40 patients with ARCO stage‐II ONFH (40 pre‐collapse hips). Patients were divided into two groups according to the 1‐year follow‐up outcomes: patient group without femoral head collapse (noncollapse group, n = 20) and patient group with collapse (collapse group, n = 20). CT scans of the hip were performed for all patients once they joined the study. Patient‐specific finite element models were generated based on these original CT images following the same procedures: segmenting the necrotic lesion and viable proximal femur, meshing the computational models, assigning different material properties according to the Hounsfield unit distribution, simulating the stress loading of the slow walking gait, and measuring the distribution of the von Mises stress. Receiver operating characteristic (ROC) curve analysis was used to evaluate the predictive performance of the maximum level of the von Mises stress. The optimal cut‐off value was selected based on the Youden index and the corresponding predictive accuracy was reported as well.

Results

The mean level of the maximum von Mises stress in the collapse group was 2.955 ± 0.539 MPa, whereas the mean stress level in the noncollapse group was 1.923 ± 0.793 MPa (P < 0.01). ROC analysis of the maximum von Mises stress found that the area under the ROC curve was 0.842 (95% CI: 0.717–0.968, P < 0.01). The maximum Youden index was 0.60, which corresponded to two optimal cut‐off values: 2.7801 MPa (sensitivity: 0.70; specificity: 0.90; predictive accuracy: 80.00%; LR+: 7), and 2.7027 MPa (sensitivity: 0.75; specificity: 0.85; predictive accuracy: 77.50%; LR+: 5).

Conclusion

Finite element analysis is a potential method for femoral head collapse prediction among pre‐collapse ONFH patients. The maximum level of the von Mises stress on the weight‐bearing surface of the femoral head could be a good biomechanical marker to classify the collapse risk. The collapse prediction method based on patient‐specific finite element analysis is, thus, suitable to apply to clinical practice, but further testing on a larger dataset is desirable.

Prognosis after autologous peripheral blood stem cell transplantation for osteonecrosis of the femoral head in the pre-collapse stage: a retrospective cohort study

OBJECTIVES

Autologous peripheral blood stem cell (auto-PBSC) transplantation is an effective therapeutic for the osteonecrosis of the femoral head (ONFH) but without prognosis estimation. This study mainly aimed to (1) determine whether auto-PBSC transplantation is a promising option, (2) assess the risk of hip-preservation failure, (3) achieve a predictive model of femoral head survival after the intervention, and (4) eventually identify clinical indications for auto-PBSC transplantation in future.

METHODS

After reviewing the in-patient database of the First Affiliated Hospital of Zhejiang Chinese Medicine University from June 2012 to June 2014, 37 eligible patients with Association Research Circulation Osseous stage I or II ONFH who were receiving intra-arterial infusion of auto-PBSCs were recruited. A case form was designed to retrieve relevant data. Hip-preservation failure was defined as the endpoint. All participants were stratified by the categorical risk of collapse, which was statistically tested through log-rank analysis. All significant factors were evaluated using Cox proportional hazards regression model, and a predictive nomogram plot was generated.

RESULTS

In total, 47 hips were followed up for 53.96 ± 21.09 months; the median survival time was 60.18 months. Among the predictors, body mass index (BMI; P = 0.0015) and Harris hip score (HHS; P < 0.0001) independently affected femoral head survival. Patients with BMI ≥ 24 kg/m² exhibited a 2.58 times higher risk of hip-preservation failure [95% confidence interval (CI), 1.32-5.45] than those with BMI < 24 kg/m², whereas those with HHS ≥ 70 exhibited a 0.19 times lower risk (95% CI, 0.09-0.38) than those with HHS < 70. Hazard ratios associated with age (P = 0.042), BMI (P = 0.012), HHS (P = 0.022), and necrotic volume (P = 0.000) were 1.038 (95% CI, 1.001-1.075), 1.379 (95% CI, 1.072-1.773), 0.961 (95% CI, 0.928-0.994), and 1.258 (95% CI, 1.120-1.412), respectively. A nomogram plot (score test P = 0.000; C-index = 0.8863) was available for the orthopedic doctor to predict hip survival probability.

CONCLUSIONS

The results suggest that intra-arterial infusion of auto-PBSCs prolongs femoral head survival. Age, BMI, HHS, and necrotic volume can influence the efficacy of this intervention. This study was approved by ethics committee of the trial center, number 2019-KL-075-01.

[Effect of icariin on early steroid-induced osteonecrosis of the femoral head in rabbits]

Objective

To explore the effect of icariin on early steroid-induced osteonecrosis of the femoral head in rabbits.

Methods

Fifty mature New Zealand rabbits (weighing, 2.5-3.0 kg) were randomly divided into control group ( n=10), model group ( n=20), and experimental group ( n=20). The rabbits of model and experimental groups were injected with lipopolysaccharide and methylprednisolone to establish the animal model of early steroid-induced osteonecrosis of the femoral head. The rabbits of experimental group were feeded with icariin solution once a day for 6 weeks since the first injection of methylprednisolone, whereas the rabbits of control and model groups were given normal saline at the same time points. The left femoral heads were removed after 6 weeks and gross morphological features were evaluated. Micro-CT scan was performed to analyze the trabecular microstructure with the following parameters: trabecular bone volume to total volume (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Tn), and trabecular separation (Tb.Sp). The Micro-CT scan was also converted to three-dimensional reconstruction images for observation. HE staining was applied to observe the trabecular structure and morphological changes of osteocytes and marrow adipocytes. It was also used to determine whether the samples of femoral heads occurred osteonecrosis based on the criteria for pathological diagnosis, and calculate the rate of empty lacunae.

Results

Seven rabbits died during the study, and 9, 16, and 18 rabbits in the control, model, and experimental groups, respectively, enrolled the final analysis. Compared with control group, the femoral head collapse and trabecular breaks were more obvious, and the trabeculae were sparse with irregular arrangement in the model group according to the results of gross observation, Micro-CT scan, and three-dimensional reconstruction images. But in the experimental group, the surface of femoral head was slight shrinking without obvious collapse, and the degeneration of trabecular structure was mild. According to bone microstructures analysis, the Tb.N, Tb.Tn, and BV/TV of femoral head in model and experimental groups were lower than those in control group, while the Tb.Sp in the model and experimental groups were significantly higher. The Tb.N, Tb.Tn, and BV/TV of femoral head in experimental group were higher than those in model group, while the Tb.Sp in the experimental group was significantly lower. The differences between groups were all significant ( P<0.05). In the model group, HE staining showed that the number of osteocytes reduced, the number of empty lacunae increased, and the marrow adipocytes piled up in the space between femoral trabeculae, some even mashed together like a cyst. In the experimental group, the trabecular structure was still relatively complete compared with model group, no obvious apoptosis of osteocytes was observed, the size and number of adipocytes were basically normal. None of the animals in control group occurred osteonecrosis of the femoral head based on the criteria for pathological diagnosis, and the incidence of osteonecrosis were 81.3% (13/16) in the model group and 66.7% (12/18) in the experimental group, and the difference was not significant ( P=0.448). The rate of empty lacunae of osteonecrotic femoral heads in the model group was 33.1%±1.4%, which was higher than that in experimental group (18.9%±0.8%) and in control group (12.7%±1.5%), and the differences between groups were significant ( P<0.05).

Conclusion

The icariin has a protective effect on the early steroid-induced osteonecrosis of the femoral head in rabbits, which can decrease osteocytes apoptosis, improve the bone microstructure, and delay such disease processes.

Identification of potential miRNA biomarkers for traumatic osteonecrosis of femoral head

Traumatic osteonecrosis of femoral head (TONFH) is a common orthopedic disease caused by physical injury in hip. However, the unclear pathogenesis mechanism of TONFH and lacking of simple noninvasive early diagnosis method cause the necessity of hip replacement for most patients with TONFH. In this study, we aimed to identify circulating microRNAs (miRNAs) by integrated bioinformatics analyses as potential biomarker of TONFH. mRNA expression profiles were downloaded from the Gene Expression Omnibus database. Then we combined two miRNA screen methods: Weighted gene co-expression network analysis and fold change based differentially expressed miRNAs analysis. As a result, we identified 14 key miRNAs as potential biomarkers for TONFH. Besides, 302 target genes of these miRNAs were obtained and the miRNA-mRNA interaction network was constructed. Furthermore, the results of Kyoto Encyclopedia of Gene and Genome pathway analysis, Gene Ontology function analysis, protein-protein interaction (PPI) network analysis and PPI network module analysis showed close correlation between these 14 key miRNAs and TONFH. Then we established receiver operating characteristic curves and identified 6-miRNA signature with highly diagnosis value including miR-93-5p (area under the curve [AUC] = 0.93), miR-1324 (AUC = 0.92), miR-4666a-3p (AUC = 0.92), miR-5011-3p (AUC = 0.92), and miR-320a (AUC = 0.89), miR-185-5p (AUC = 0.89). Finally, the results of quantitative real-time polymerase chain reaction confirmed the significantly higher expression of miR-93-5p and miR-320a in the serum of patients with ONFH. These circulating miRNAs could serve as candidate early diagnosis markers and potential treatment targets of TONFH.

Primary stability of calcar-guided short-stem total hip arthroplasty in the treatment of osteonecrosis of the femoral head: migration analysis using EBRA-FCA

INTRODUCTION

Osteonecrosis of the femoral head (ONFH) is a disabling condition that often results in secondary arthritis necessitating total hip arthroplasty (THA). Short-stem THA has constantly gained popularity. It remains controversial, whether ONFH represents a risk factor for failure after the implantation of short stems with pronounced metaphyseal anchorage. The potential spread of the osteonecrotic area and bone marrow edema into the metaphyseal bone might result in compromised stability. Early implant migration is considered predictive of subsequent aseptic loosening. The purpose of this study was a migration analysis of a modern, calcar-guided short-stem implant in patients with ONFH in a mid-term follow-up.

MATERIALS AND METHODS

This retrospective analysis investigated the migration pattern of 45 calcar-guided short stems in patients with ONFH, using Einzel-Bild-Roentgen-Analyse Femoral-Component-Analysis (EBRA-FCA). Influencing factors such as ARCO categories, age, gender, body weight and BMI were analyzed. Complications and adverse events were documented.

RESULTS

At mid-term [48.1 months (SD 20.7 months)], mean axial migration was 1.56 mm (SD 1.77 mm). Mean migration rate stabilized after 2 years. No influence of ARCO categories, age and BMI was found. A tendency of increased axial migration was observed in male patients and in overweight patients. No revision surgeries had to be performed during follow-up.

CONCLUSION

The results indicate a migration pattern comparable to that of primary osteoarthritis patients with slight initial migration under full load followed by subsequent stabilization in the metaphyseal femur. The 100% survival rate at mid-term supports the usage of this short-stem design in patients with ONFH.

A comparative study of cortico-cancellous iliac bone graft with or without the combination of vascularized greater trochanter flap for the management of femoral head osteonecrosis: a minimum 6 years follow-up

BACKGROUND

To compare the mid-long-term clinical and radiological outcomes between a combination of cortico-cancellous iliac bone graft with vascularized greater trochanter flap (Group A) and isolate iliac bone graft (Group B) in the treatment of Osteonecrosis of the Femoral Head (ONFH).

METHODS

From January 2006 to December 2012, 123 patients (135 hips) who underwent abovementioned hip-preserving surgeries were included for analysis. Clinical outcomes were assessed based on Harris Hip Score (HHS) System and The Western Ontario and McMaster University Index (WOMAC) scores between the preoperative and the last follow-up. A series of postoperative X-rays were compared to preoperative images for radiological evaluation.

RESULTS

The HHS in Group A and B were enhanced from 50.57 ± 3.39 to 87.60 ± 4.15 and from 50.24 ± 3.30 to 85.18 ± 6.45, respectively, which both showed significance between preoperative and postoperative latest follow-up (p < 0.001). Group A revealed better improvement in terms of HHS (p = 0.017). The WOMAC total, postoperative stiffness, difficulty subscale scores in Group A showed better outcomes when compared to Group B (p < 0.01), while pain improvement between these two groups revealed no significance (p = 0.402). Besides, Group A suggested better necrotic region repair (p = 0.020), but no femoral head collapse difference in terms of Association Research Circulation Osseous classification change was found (p > 0.05).

CONCLUSIONS

A combination of cortico-cancellous iliac bone graft and concurrent vascularized greater trochanter flap with the lateral femoral circumflex transverse branch has been proved can obtain better functional and radiological results than isolate iliac bone grafting, which is attributed to blood reconstruction of the femoral head.

The role of the subchondral layer in osteonecrosis of the femoral head: analysis based on HR-QCT in comparison to MRI findings

BACKGROUND

Non-traumatic avascular osteonecrosis of the femoral head (ONFH) is a severe disease causing destruction of the hip joint, often necessitating total hip arthroplasty (THA) even in young patients. Magnetic resonance imaging (MRI) is commonly used for diagnosis of ONFH, but provides limited insight into the subchondral bone microstructure.

PURPOSE

To analyze routine MRI findings in comparison to high-resolution quantitative computed tomography (HR-QCT) with a special focus on the subchondral layer and to estimate the importance of differences determining the indication for THA.

MATERIAL AND METHODS

Twelve patients with ONFH were included before THA. Preoperative MRI and HR-QCT of the retrieved femoral heads were aligned using a registration algorithm. Pathological findings and trabecular bone parameters in matched areas were analyzed by two readers. McNemar, marginal homogeneity test, and Pearson's correlation coefficient were used for comparison.

RESULTS

Subchondral delamination was found in nine cases on HR-QCT, but missed or underestimated in all but one case on MRI ( P = 0.016). Chondral discontinuity was found in all cases on HR-QCT and in two cases on MRI ( P = 0.016). Areas of complete bone resorption on HR-QCT were linked to high signal intensity on 3D gradient-echo MRI sequences with water-selective excitation, while there was no correlation between trabecular bone parameters and MRI signal intensities in other areas ( P = 0.304).

CONCLUSION

Subchondral delamination, subchondral resorption, and chondral discontinuity are found frequently in advanced stages of ONFH. These lesions tend to be underestimated on conventional MRI. Our results support the importance of CT imaging in the evaluation of ONFH.

Use of an offset head center acetabular shell in difficult primary total hip arthroplasties

Several conditions may predispose patients to development of antero-lateral acetabular bone deficiency, including developmental dysplasia of the hip, osteonecrosis, or septic arthritis, among others. This may compromise the ability to gain acetabular component stability and impair reliable fixation. Large acetabular shells have often been used to achieve adequate fixation in scenarios of severe bone loss, however, these techniques have been shown to elevate the center of rotation (COR) of the hip and alter hip biomechanics. Recently, a new acetabular shell was developed with a goal of maintaining the native hip COR while achieving good fixation with standard instrumentation and technique. Previous radiographic studies have demonstrated the efficacy of this shell in lowering hip COR. In this case series, we demonstrate the use of this shell in patients with difficult hip pathologies. We have demonstrated how this offset COR acetabular shell may help bring down the COR of the hip in these quite challenging cases utilizing conventional techniques.

Analysis of the long-term efficacy of core decompression with synthetic calcium-sulfate bone grafting on non-traumatic osteonecrosis of the femoral head

OBJECTIVE

to investigate the safety and long-term efficacy of core decompression with synthetic calcium-sulfate bone grafting on non-traumatic osteonecrosis of the femoral head.

METHOD

a total of 76 patients with non-traumatic osteonecrosis of the femoral head were admitted to our hospital from February 2012 to November 2014 and included in the study. All the patients were treated by core decompression with synthetic calcium-sulfate bone grafting. After treatment, the patients were followed-up for 12 months. The operation time, intraoperative blood loss, and perioperative complications were also recorded intraoperatively to evaluate the clinical efficacy and safety. The preoperative and postoperative pain scores measured by visual analogy score (VAS) were also recorded and compared.

RESULTS

all of the 76 patients were successfully operated and included in the study. The mean operation time was 34.6±14.2 min, and the intraoperative blood loss was 23.6±8.9 mL. The patients hip functions were assessed on the basis of the Harris hip score, 3 and 12 months after operation. The excellent rates 3 and 12 months after operation were significantly higher than those before operation (P<0.05). The imaging stabilities of the hip joints 3 and 12 months after operation were significantly higher than those before operation (P<0.05). The patient postoperative pain scores (VAS score) gradually decreased. The VAS scores 12 months after operation were significantly lower than those before operation (P<0.05).

CONCLUSION

the long-term efficacy of core decompression with synthetic calcium-sulfate bone grafting on non-traumatic osteonecrosis of the femoral head is good and accompanied with significantly improved postoperative joint functions.

Total hip arthroplasty following illicit drug abuse

BACKGROUND

The role of illicit drug abuse in total joint arthroplasty is largely unknown and is likely underestimated. Patients with drug addictions often suffer from septic osteoarthritis or a necrosis of the femoral head. Purpose of the study was to evaluate the operative management and clinical outcome of total hip replacement in patients with a history of intravenous drug abuse.

METHODS

This retrospective study included 15 patients with a history of intravenous drug abuse who underwent total hip arthroplasty. A total of 6 females and 9 males with an average age of 34.3 years were identified. Ten patients presented an acute bacterial coxitis (Coxitis-group) and five an aseptic osteonecrosis of the femoral head (Osteonecrosis-group).

RESULTS

Ten patients with a bacterial coxitis underwent a two-staged total hip arthroplasty (THA), with temporary insertion of a drug-eluting spacer. Five patients with a necrosis of the femoral head were primarily treated with THA. All patients developed multiple re-infections after insertion of a drug-eluting spacer or THA. Only two patients finally achieved a THA without infection in the period of 3.9 years follow-up. The other 13 patients underwent a Girdlestone arthroplasty (7 patients) or total joint replacement with a chronic fistula (6 patients).

CONCLUSION

THA in patients with illicit drug abuse shows a low success rate. Following septic osteoarthritis or osteonecrosis in drug-addicted patients, we recommend a two-stage procedure with temporary insertion of a drug-eluting spacer. THA might follow only under strict premises.

Osteonecrosis of the Femoral Head: Etiology, Investigations, and Management

Femoral head osteonecrosis is a condition caused by a compromise of the blood supply of the femoral head. The precarious blood supply of the head and its role as a major weight-bearing joint makes it one of the most common bones to be affected by osteonecrosis. We describe the etiology, clinical presentation, investigations and common management options used nowadays to treat it.

Hip arthroplasty for osteonecrosis of the femoral head secondary to alcohol abuse

Although the challenges of hip arthroplasty for avascular necrosis (AVN) are known, limited data exist to describe patient demographics and outcomes in the setting of AVN attributed to alcoholism. We retrospectively identified 43 patients (62 hips) who underwent primary hip arthroplasty between 1999 and 2016 for a diagnosis of AVN of the femoral head with a concomitant diagnosis of alcohol abuse and minimum follow-up of 2 years (mean, 8.6 years). The mean age was 51 years, predominantly male (88%), with a high rate of comorbidities. History of cigarette smoking was prevalent (65%). Mean length of stay was 5.3 days, which is prolonged due to a high prevalence of acute postoperative alcohol withdrawal (14.5% of cases). There were 5 early (≤2 years) reoperations (8% of hips) for instability, periprosthetic acetabular fracture and component loosening, heterotopic ossification, superficial infection, and acute periprosthetic infection. There were no additional radiographic failures. The mean postoperative Hip dysfunction and Osteoarthritis Outcome Score for Joint Replacement was 97.8 ± 7.8, indicative of excellent outcomes at final follow-up of 2 to 18 years. Early risks associated with hip replacement surgery must be communicated to the predominantly young male subgroup of patients with AVN attributed to alcoholism, but these patients may achieve excellent mid- to long-term outcomes.

The role of cell therapies and hip arthroscopy in the management of osteonecrosis: an update

The exact pathophysiology of osteonecrosis of the femoral head (ONFH) is still unknown. There is evidence to suggest that in ON there is decreased population and altered function of the mesenchymal stem cells (MSCs) of the femoral head. This could influence both the actual occurrence of ON itself and the repair process that follows. Hence, in such an environment it only is rational to consider the use of cell-based treatments to potentially regenerate lost or damaged bone. The aim of this review is to provide an up-to-date, evidence-based information in the use of cell therapies in the treatment of nontraumatic ONFH and the use of hip arthroscopy in the field.

Safflower (Carthamus tinctorius L.) polysaccharide attenuates cellular apoptosis in steroid-induced avascular necrosis of femoral head by targeting caspase-3-dependent signaling pathway

The present study aimed to investigate the effects of a purified polysaccharide (SPS) from the safflower in a cellular model of steroid-associated necrosis of the femoral head (SANFH), which was established in primary murine osteoblasts suffering dexamethasone pretreatment. After treatment with SPS (25, 50 and 100 μg/ml), the degree of necrosis induced by dexamethasone was significantly reduced in osteoblasts as evidenced by an increase of cell viability and a decrease of apoptosis in osteoblasts. Furthermore, pretreatment with SPS (25, 50 and 100 μg/ml) significantly attenuated the activation of caspase-3 and cleavage of PARP relative to the model control cells. The addition of caspase-3 inhibitor (Z-DEVD-FMK) in dexamethasone-treated osteoblasts resulted in the inefficiency of SPS for inhibiting cellular apoptosis. Dose-dependent increases in alkaline phosphatase (ALP) activity, collagen synthesis and mineralization were also observed in SPS-treated osteoblasts at 72 h. The present study demonstrates that SPS may alleviate dexamethasone associated osteonecrosis by inhibiting caspsae-3-mediated apoptosis and may provide an alternative treatment for SANFH.

Real-time computerised tomography assisted porous tantalum implant in ARCO stage I-II non-traumatic osteonecrosis of the femoral head: minimum five-year follow up

PURPOSES

This study was established to investigate the medium-term clinical effect of real-time CT assisted porous tantalum implant for the treatment of ARCO stage I-II non-traumatic osteonecrosis of the femoral head (ONFH).

METHODS

This study comprised 24 ONFH patients (29 hips) who were treated with intra-operative real-time CT accurate rapid positioning assisted drilling decompression, lesion removal and porous tantalum implant. Harris score, VAS score and imaging in pre-operation and follow-up period were recorded.

RESULTS

The average operative time and intra-operative blood loss were 72.6 min and 158.8 ml, respectively. The mean follow-up was 5.4 years. No femoral head penetrating, wound infection, and death occurred. Harris and VAS score improved significantly (73.78 vs. 88.11; 7.13 vs. 2.66) at last follow-up (P < 0.05). The functional improvement and pain relief rate was 100% at six months after operation. The effective rate was 86.21% at 12 months after operation and last follow-up. Five pre-operative ARCO stage I hips had no radiographic progress. Meanwhile, four among the 24 ARCO stage II hips progressed into stage III between eight and 12 months after surgery, among which two progressed into stage IV and two remained in stage III at the last follow-up. The average value of Kerboul combined necrotic angle was 263.24°. There was no progress in Kerboul combined necrotic angle among the grades 2 and 3 patients. However, among the six cases at grade 4, four cases with post-operative progress, two patients converted to THA.

CONCLUSIONS

Our technique is safety and effective in the treatment of ARCO stage I-II non-traumatic ONFH.

Porous Se@SiO2 nanocomposites protect the femoral head from methylprednisolone-induced osteonecrosis

Background

Methylprednisolone (MPS) is an important drug used in therapy of many diseases. However, osteonecrosis of the femoral head is a serious damage in the MPS treatment. Thus, it is imperative to develop new drugs to prevent the serious side effect of MPS.

Methods

The potential interferences Se@SiO₂ nanocomposites may have to the therapeutic effect of methylprednisolone (MPS) were evaluated by classical therapeutic effect index of acute respiratory distress syndrome (ARDS), such as wet-to-dry weight ratio, inflammatory factors IL-1β and TNF-α. And oxidative stress species (ROS) index like superoxide dismutase (SOD) and glutathione (GSH) were tested. Then, the protection effects of Se@SiO₂ have in osteonecrosis of the femoral head (ONFH) were evaluated by micro CT, histologic analysis and Western-blot analysis.

Results

In the present study, we found that in the rat model of ARDS, Se@SiO₂ nanocomposites induced SOD and GSH indirectly to reduce ROS damage. The wet-to-dry weight ratio of lung was significantly decreased after MPS treatment compared with the control group, whereas the Se@SiO₂ did not affect the reduced wet-to-dry weight ratio of MPS. Se@SiO₂ also did not impair the effect of MPS on the reduction of inflammatory factors IL-1β and TNF-α, and on the alleviation of structural destruction. Furthermore, micro CT and histologic analysis confirmed that Se@SiO₂ significantly alleviate MPS-induced destruction of femoral head. Moreover, compared with MPS group, Se@SiO₂ could increase collagen II and aggrecan, and reduce the IL-1β level in the cartilage of femoral head. In addition, the biosafety of Se@SiO₂ in vitro and in vivo were supported by cell proliferation assay and histologic analysis of main organs from rat models.

Conclusion

Se@SiO₂ nanocomposites have a protective effect in MPS-induced ONFH without influence on the therapeutic activity of MPS, suggesting the potential as effective drugs to avoid ONFH in MPS therapy.