Femoral Head Vascularity: Implications Following Trauma and Surgery About the Hip

Modified Smith-Petersen approach with rectus-sparing reduces severe avascular necrosis for developmental dysplasia of the hip at walking age: minimum 5-year follow-up

BACKGROUND

Developmental dysplasia of the hip (DDH) is one of the most common orthopedic malformations in children. Open reduction for DDH at walking age remains a major concern. The goal of this study is to evaluate the mid-term effect of a modified Smith-Petersen approach which preserves the rectus femoris on DDH at walking age, in particular avascular necrosis (AVN).

METHODS

A retrospective review of DDH patients aged between 12 and 24 months was carried out between January 2010 and June 2016. Open reduction through the Smith-Petersen approach (Group A) and modified Smith-Petersen approach, which preserves the rectus femoris (Group B), were both used. Measurement of hip geometry included acetabular index, the International Hip Dysplasia Institute classification, and AVN degree. Clinical records included operation time, bleeding volume, and abduction angle.

RESULTS

There were 101 children (119 hips) with DDH who met the inclusion criteria. There were 66 hips in Group A and 53 in Group B. The mean surgical age at open reduction was 17.0 ± 2.4 months, with a mean 104.9 ± 19.5 months at last follow-up. There was no statistical difference in surgical age between the two groups (17.2 vs. 16.4 months). There was no significant difference in the incidence of all types of clinically significant AVN between group A and group B (27.3 vs. 18.9%), but the incidence of severe AVN was lower in group B (19.7 vs. 5.7%, P = 0.026). In addition, the lower the age at the time of open reduction, the lower the severity of AVN (P = 0.002).

CONCLUSIONS

These mid-term data suggest that the modified Smith-Petersen approach with rectus-sparing could reduce severe AVN more than the classical Smith-Peterson approach in open reduction in DDH at walking age. In addition, early open reduction can reduce the postoperative degree of AVN.

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.

Corticoperiosteal Pedicle Flap of Greater Trochanter for Salvage of Old Femoral Neck Fracture in Children: Outcomes After a Minimum 5 Years Follow-up

BACKGROUND

Old femoral neck fracture (OFNF) generally refers to fractures for more than 3 weeks. Corticoperiosteal pedicle flap of greater trochanter (CPPF-GT) was designed to restore blood supply and donor bone for OFNF. This study aimed to assess the efficacy and radiographic results of CPPF-GT for treatment of OFNF in children after a minimum 5 years follow-up.

METHODS

Twenty-three patients with OFNFs, age from 8 to 16 years old, who underwent open reductions, fracture fixations, and transpositions of CPPF-GTs were retrospectively reviewed. Clinical and radiological outcomes, including union, nonunion, avascular necrosis of femoral head, limb shortening, coxa vara, premature epiphyseal closure and Ratliff's assessment, were investigated in the postoperative follow-up. The results were compared with previously published joint-salvage study of OFNFs.

RESULTS

All patients were followed for an average of 5.9 years (range: 5 to 10 years). All cases (100%) achieved hip unions at an average duration of 3.5 months (range: 2.5 to 5 months). No nonunion hip was observed. Three hips (13.0%) progressed to avascular necrosis of femoral head after 1.5 to 3 years of operation, respectively, and the revision surgeries to hip replacements were conducted. Premature epiphyseal closures were observed in 3 hips. Three hips visibly presented an average 2 cm shortening of the femoral neck. Coxa vara deformities were observed in 2 hips. According to the Ratliff's criteria, there were 20 cases (87.0%) with satisfactory union, good results were achieved in 17 cases, fair results in 3 cases, and poor result in 3 cases.

CONCLUSIONS

Corticoperiosteal pedicle flap of greater trochanter is an effective and desirable option for treating old femoral neck fractures in children with a low rate of avascular necrosis and without nonunion.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Intraoperative monitoring of femoral head perfusion in adult femoral neck fractures

Objectives:

To validate a novel intraoperative method of quantifying femoral head perfusion in adult patients with femoral neck fractures and to determine whether the lack of a perfusion waveform correlates with the development of osteonecrosis, nonunion, or reoperation.

Design:

Prospective cohort.

Setting:

Level 1 trauma center.

Patients/Participants:

Nineteen patients with 20 acute femoral neck fractures treated with hip-preserving surgical fixation. All patients underwent intraoperative quantification of femoral head perfusion.

Intervention:

Intraoperative quantification of femoral head perfusion pressure and waveform utilizing an intracranial pressure monitor.

Main outcome measurements:

Radiographic union, avascular necrosis, revision surgery.

Results:

Nineteen patients (8 male, 11 female, average age 56 ± 21 years) with 20 femoral neck fractures were enrolled. Eight fractures were stable (Garden 1-2/OTA B1.1–1.3) and 12 were unstable (Garden 3-4/OTAB2.1–3.3). A waveform was present in 12 of 20 cases. The average pressures were systolic 36.8 mm Hg, diastolic 30.8 mm Hg, pulse pressure 6.0 mm Hg. A perfusion waveform was significantly associated with advanced age (P = 0.02) and accompanied by trend toward stable fracture patterns. There were 4 deaths during the 1-year follow-up period (20%), and there were 5 conversions to total hip arthroplasty (25%). There was no significant association between revision surgery or death with the absence of a waveform.

Conclusions:

Our study demonstrated the feasibility of a relatively low cost, minimally invasive, technique to quantify femoral head perfusion. In our limited sample, the absence of perfusion did not correlate with our main outcomes; however, the trend toward correlation with increased fracture displacement was as expected. A larger cohort of patients will be needed to detect a significant difference between those with and without a perfusion waveform with regards to our primary outcomes. Further study is needed to delineate the role such data may play in medical decision making at the time of index surgery.

Level of Evidence:

Prognostic Level II.

The endothelium-bone axis in development, homeostasis and bone and joint disease

Blood vessels form a versatile transport network that is best known for its critical roles in processes such as tissue oxygenation, metabolism and immune surveillance. The vasculature also provides local, often organ-specific, molecular signals that control the behaviour of other cell types in their vicinity during development, homeostasis and regeneration, and also in disease processes. In the skeletal system, the local vasculature is actively involved in both bone formation and resorption. In addition, blood vessels participate in inflammatory processes and contribute to the pathogenesis of diseases that affect the joints, such as rheumatoid arthritis and osteoarthritis. This Review summarizes the current understanding of the architecture, angiogenic growth and functional properties of the bone vasculature. The effects of ageing and pathological conditions, including arthritis and osteoporosis, are also discussed.

The effect of calcar femoral neck plating on vascularity of the femoral head and neck

Aims

Surgical treatment of young femoral neck fractures often requires an open approach to achieve an anatomical reduction. The application of a calcar plate has recently been described to aid in femoral neck fracture reduction and to augment fixation. However, application of a plate may potentially compromise the regional vascularity of the femoral head and neck. The purpose of this study was to investigate the effect of calcar femoral neck plating on the vascularity of the femoral head and neck.

Methods

A Hueter approach and capsulotomy were performed bilaterally in six cadaveric hips. In the experimental group, a one-third tubular plate was secured to the inferomedial femoral neck at 6:00 on the clockface. The contralateral hip served as a control with surgical approach and capsulotomy without fixation. Pre- and post-contrast MRI was then performed to quantify signal intensity in the femoral head and neck. Qualitative assessment of the terminal arterial branches to the femoral head, specifically the inferior retinacular artery (IRA), was also performed.

Results

Quantitative MRI revealed a mean reduction of 1.8% (SD 3.1%) of arterial contribution in the femoral head and a mean reduction of 7.1% (SD 10.6%) in the femoral neck in the plating group compared to non-plated controls. Based on femoral head quadrant analysis, the largest mean decrease in arterial contribution was in the inferomedial quadrant (4.0%, SD 6.6%). No significant differences were found between control and experimental hips for any femoral neck or femoral head regions. The inferior retinaculum of Weitbrecht (containing the IRA) was directly visualized in six of 12 specimens. Qualitative MRI assessment confirmed IRA integrity in all specimens.

Conclusion

Calcar femoral neck plating at the 6:00 position on the clockface resulted in minimal decrease in femoral head and neck vascularity, and therefore it may be considered as an adjunct to laterally-based fixation for reduction and fixation of femoral neck fractures, especially in younger patients.

Cite this article: Bone Jt Open 2021;2(8):611–617.

Long-term results after over 17 years - Intramedullary gliding nail as treatment for traumatic femoral neck fractures

Background

For the treatment of femoral neck fracture there are many different implants present on the market. Postoperative complications still exist.

Patients and methods

The aim of this retrospective study was to evaluate the Gliding Nail in patients with medial femoral neck fractures and their long-term complications.

Results

In a collective of 113 patients we had all together 21 major complications in 2018.12/113 minor complications in 2008 and all together 13/78 in 2018 has been detected.

Conclusions

The Gliding Nail as an intramedullary implant shows a high load-bearing capacity with a high rotational stability and a low cut-out rate.

[Treatment of osteonecrosis of the femoral head with vascularized bone grafting]

Objective

To summarize the current progress of vascularized bone grafting in the treatment of osteonecrosis of the femoral head (ONFH), and to provide reference for treatment of ONFH.

Methods

The literature at home and abroad on the treatment of ONFH with vascularized bone grafting was reviewed, and the mechanism, operating methods and effectiveness, indications, and complications were summarized.

Results

Vascularized bone grafting is a commonly used clinical hip-preserving operation. By replacing necrotic bone tissue with vascularized bone, it can rebuild the blood circulation system, promote the healing of the necrotic area, and provide biomechanical support for the necrotic area of the femoral head, prevent the joint surface collapse. The main operations include the vascularized iliac bone flap grafting, the vascularized greater trochanter bone flap grafting, and the vascularized fibular grafting. The clinical application has achieved certain effectiveness, and the different procedures are suitable for different types of patients. The procedures need to be selected based on the patient's overall condition, the cause of ONFH, the necrosis stage, and the degree of the evaluation.

Conclusion

Vascularized bone grafting has a definite effectiveness in the treatment of ONFH in the young and middle-aged. It can significantly improve hip joint function, control the further development of the disease to a great extent, effectively delay or even avoid hip arthroplasty. It is a reliable hip-preserving operation worthy of promotion.

CaO2/gelatin oxygen slow-releasing microspheres facilitate tissue engineering efficiency for the osteonecrosis of femoral head by enhancing the angiogenesis and survival of grafted bone marrow mesenchymal stem cells

The osteonecrosis of femoral head (ONFH), a common refractory disease, is still not fully understood today. Hypoxia caused by ischemia is not only an important pathogenic factor but also a critical challenge for the survival of seed cells in the tissue engineering therapy of ONFH. To explore an efficient strategy to treat ONFH by targeting hypoxia, newly designed CaO₂/gelatin microspheres were composited with 3D printed polycaprolactone/nano-hydroxyapatite (PCL/nHA) porous scaffold, sodium alginate/gelatin hydrogel, and bone marrow mesenchymal stem cells (BMSCs) to develop a novel tissue engineering scaffold and then transplanted into the core depression area of the ONFH rabbit model. The current data demonstrated that CaO₂/gelatin microspheres can constantly release oxygen for 19 days. In vitro assays with BMSCs illustrated that scaffolds have high biocompatibility and are favorable for cell proliferation in extreme hypoxia (1% O₂). The in vivo study demonstrated that the transplanted scaffold with oxygen-generating microspheres significantly enhanced the osteogenic and angiogenic effects compared to the scaffold without microspheres. Further assessments revealed that microspheres in the scaffold can reduce the local cell apoptosis and enhance the survival of grafted cells in the host. Collectively, the present study developed a novel oxygen slow-releasing composite scaffold, which can facilitate tissue engineering efficiency for treating the osteonecrosis of the femoral head by enhancing the angiogenesis and survival of grafted stem cells.