[Imaging and classification of avascular femoral head necrosis]

"Mulligan Bent Leg Raise" Technique in Avascular Necrosis

This case report examines the effectiveness of the "Mulligan bent leg raise" (MBLR) method for treating femoral head avascular necrosis (AVN). A professional physiotherapist directed a six-week rehabilitation program for a 37-year-old male patient with AVN that included this innovative physiotherapeutic method. According to radiographic results and standardized evaluations, the patient showed significant improvements in hip range of motion, functional ability, and pain levels. As a viable supplement to conventional rehabilitation techniques, the MBLR method has shown promise in improving joint function and reducing symptoms in individuals with acute compartment syndrome. The present study provides significant contributions to the discipline. It highlights the necessity for more investigation to examine the wider relevance and enduring effectiveness of this methodology in various population affected.

Experimental study of a 3D-printing technique combined with biphasic calcium phosphates to treat osteonecrosis of the femoral head in a canine model

OBJECTIVE

This study was aimed to use a digital design of 3D-printing technology to create a surgical navigation template. At the same time, biphasic calcium phosphate (BCP) was applied to treat osteonecrosis of the femoral head (ONFH) in animal models, based on accurate positioning of necrotic lesions in the navigation templates and observation of its therapeutic effect.

METHODS

Fifteen healthy adult male and female beagle dogs weighing 20 + 2 kg were randomly divided into three groups (n = 5) after establishing a model of ONFH using the liquid nitrogen freezing method. Each model underwent necrotic lesion creation and BPC implantations on one side of the femoral head and only necrotic lesion creation on the other side of the femoral head. Each group underwent CT examination, gross observation, histological examination and immunohistochemical staining at 6 weeks, 12 weeks and 18 weeks postoperatively.

RESULTS

At weeks 6, 12, and 18, CT and gross examination showed that the necrotic area in the experimental group was basically intact and had been completely raised by BCP material. In the control group, there were signs of bone repair in the femoral head, but there were still large bone defects and cavities. At week 18, extensive collapse of the cartilage surface was observed. Through histological examination, in the experimental group at 12 and 18 weeks, a large number of new and reconstructed bone trabeculae containing a large amount of collagen fibres were observed (P < 0.05), while in the control group, there was extensive necrosis of the bone trabeculae without cellular structural areas. Immunohistochemical examination observation: A large number of CD31-positive cells were observed in the experimental group at 6 weeks, gradually decreasing at 12 and 18 weeks (P < 0.05), while a small number of CD31-positive cells were observed in the control group at 18 weeks.

CONCLUSION

The 3D-printed navigation template can accurately locate ONFH lesions. Implantation of BCP material can effectively play a supporting role, prevent the collapse of the loading surface, and induce bone formation and angiogenesis to some extent.

Advances in experimental models of osteonecrosis of the femoral head

Background

Osteonecrosis of the femoral head (ONFH) is a devastating disease affecting young adults, resulting in significant pain, articular surface collapse, and disabling dysfunction. ONFH can be divided into two broad categories: traumatic and non-traumatic. It has been established that ONFH results from an inadequate blood supply that causes the death of osteocytes and bone marrow cells. Nonetheless, the precise mechanism of ONFH remains to be elucidated. In this regard, preclinical animal and cell models to study ONFH have been established to assess the efficacy of various modalities for preventing and treating ONFH. Nevertheless, it should be borne in mind that many models do not share the same physiologic and metabolic characteristics as humans. Therefore, it is necessary to establish a reproducible model that better mimics human disease.

Methods

We systematically reviewed the literatures in regard to ONFH experimental models over the past 30 years. The search was performed in PubMed and Web of Science. Original animal, cell studies with available full-text were included. This review summarizes different methods for developing animal and cell experimental models of ONFH. The advantages, disadvantages and success rates of ONFH models are also discussed. Finally, we provide experimental ONFH model schemes as a reference.

Results

According to the recent literatures, animal models of ONFH include traumatic, non-traumatic and traumatic combined with non-traumatic models. Most researchers prefer to use small animals to establish non-traumatic ONFH models. Indeed, small animal-based non-traumatic ONFH modeling can more easily meet ethical requirements with large samples. Otherwise, gradient concentration or a particular concentration of steroids to induce MSCs or EPCs, through which researchers can develop cell models to study ONFH.

Conclusions

Glucocorticoids in combination with LPS to induce ONFH animal models, which can guarantee a success rate of more than 60% in large samples. Traumatic vascular deprivation combines with non-traumatic steroids to induce ONFH, obtaining success rates ranging from 80% to 100%. However, animals that undergo vascular deprivation surgery may not survive the glucocorticoid induction process. As for cell models, 10-6mol/L Dexamethasone (Dex) to treat bone marrow stem cells, which is optimal for establishing cell models to study ONFH.

The translational potential of this article

This review aims to summarize recent development in experimental models of ONFH and recommended the modeling schemes to verify new models, mechanisms, drugs, surgeries, and biomaterials of ONFH to contribute to the prevention and treatment of ONFH.

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.

Evolutionary course of the femoral head osteonecrosis: Histopathological - radiologic characteristics and clinical staging systems

Osteonecrosis of the femoral head (ONFH) is a recalcitrant ischemic disorder, which could be classified into two major categories: traumatic and nontraumatic. Regardless of different risk factors, it has been testified that ONFH results from primitive vascular problems, leading to temporary or permanent loss of blood supply to bone tissue. Histopathological and microarchitectural alterations ensues, which is a gradual evolutionary process involving bone marrow and osteocyte necrosis, progressive destruction of subchondral bone, unsuccessful reparative process, and eventual articular collapse and degenerative arthritis. Based on the imaging features of ONFH, different classification systems have been developed to evaluate the severity and prognosis of the disease, which is pivotal for implementation of treatment strategy, especially the joint-preserving surgery. However, patients classified with the same severity stage, especially in the peri-collapse stage, sometimes responded differently after similar joint-preserving surgery. The unusual phenomenon may be attributed to the limitation of the current imaging classification systems, which might underestimate the disease severity, especially when referring to the early stages. In this review, we briefly summarize the etiology and pathogenesis of ONFH. The imaging features and staging classification systems of ONFH are also described. More importantly, we focus on histopathological and microstructural alterations of the femoral head, and provide an overview of their essential contribution to ONFH progression. Given the observation of discordance between imaging characteristics and histopathological alterations, a substantial amount of research on the relationship between imaging and histopathological features is required to further modify and revise the current wide-accepted classification systems.

Nontraumatic avascular necrosis of the femoral head : Arthroscopic and navigation-supported core decompression

OBJECTIVE

The aim is to address core decompression and pathologies of the femoral head, treating them during the same procedure. Furthermore, radiation exposure will be reduced.

INDICATIONS

Femoral head necrosis ARCO (Association Research Circulation Osseous) stages I-III.

CONTRAINDICATIONS

Progressive femoral head necrosis as ARCO stages IIIC-IV.

SURGICAL TECHNIQUE

Arthroscopically navigated core decompression of the femoral head using an established optoelectronic system with fluoro-free software module. First, hip joint arthroscopy was performed and further pathologies were treated. Second, core decompression was navigated by a navigation pointer and drill sleeve to reach the correct target point. After visualization, the procedure is repeated 3-5 times.

POSTOPERATIVE MANAGEMENT

Limited weight bearing of the operated leg (20 kg) for 10-14 days. Active or passive continuous motion machine for 4 weeks. Adjuvant postoperative indomethacin therapy for 10 days to reduce pain and bone marrow edema.

RESULTS

From May 2018 to January 2019, 7 patients (male = 4; 40 ± 9 years) underwent arthroscopically navigated core decompression with 2 (29%) and 5 (71%) patients being classified as ARCO II and III, respectively. Preoperatively, all patients reported load-dependent pain. In all cases, we could identify synovitis, which results in soft tissue release and synovectomy. Furthermore, 4 of 7 patients had an additional labrum lesion, which is addressed by refixation or shrinking.

DISCUSSION

Compared to the conventional technique, this fluoro-free navigation procedure allows more precise drilling. Moreover, additional pathologies, as found in all our cases, could be simultaneously addressed. The intraoperative radiation exposure for the patient and surgical team could also be reduced. Although arthroscopically assisted core decompression requires more preparation time, there are advantages over conventional surgery.

Effectiveness of extracorporeal shock wave monotherapy for avascular necrosis of femoral head: A systematic review protocol of randomized controlled trial

BACKGROUND

Previous clinical studies have reported that extracorporeal shock wave (EPSW) monotherapy can effectively treat avascular necrosis of femoral head (ANFH). However, no systematic review has been conducted to assess its effectiveness and safety for patients with ANFH. Therefore, this study will systematically assess the effectiveness and safety of EPSW monotherapy for patients with ANFH.

METHODS

In this study, the following electronic databases will be searched from their inceptions to the present: Cochrane Library, EMBASE, PUBMED, Cumulative Index to Nursing and Allied Health Literature, China National Knowledge Infrastructure, and Chinese Biomedical Literature Database. This study will include randomized controlled trials for assessing the effectiveness and safety of EPSW monotherapy for patients with ANFH. Two independent authors will perform study selection, data extraction, and methodology assessment. RevMan 5.3 software will be used for statistical analysis.

RESULTS

This systematic review will provide latest summary evidence of EPSW monotherapy for patients with ANFH through assessing the outcome measurements. The primary outcome is pain intensity, which can be measured by visual analog scale or relevant measurement tools. The secondary outcomes are functional status of attacked femoral head, as assessed by Western Ontario and McMaster Universities Osteoarthritis Index, or other relevant scales; quality of life, as evaluated by The 36-Item Short Form Health Survey, or related instruments; and adverse events.

CONCLUSION

The results of this study may provide the latest evidence for assessing the effectiveness and safety of EPSW for the treatment of ANFH.

DISSEMINATION AND ETHICS

This study does not require ethical approval, because no individual data will be involved in this systematic review. The findings of this study will be published through a peer-reviewed journal.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019124665.