Autologous (non-vascularised) fibular grafting with recombinant bone morphogenetic protein-7 for the treatment of femoral head osteonecrosis: preliminary report

Conversion Total Hip Arthroplasty After Failed Pedicled Peri-Hip Bone Flap Grafting: The Chinese Experience

BACKGROUND

This study investigated the perioperative outcomes of patients undergoing conversion total hip arthroplasty (THA) after failed peri-hip bone flap grafting (PBFG) and compared them with those patients undergoing primary THA for osteonecrosis of the femoral head (ONFH).

METHODS

From January 2010 to December 2021, 163 Chinese patients (163 hips) were treated by conversion THA after failed PBFG (containing 94 patients who had pedicled vascularized iliac bone flap grafting and 69 patients who had pedicled vascularized greater trochanter bone flap grafting), and 178 Chinese patients were treated by primary THA. The preoperative baseline data and perioperative indicators in both groups were compared.

RESULTS

In the conversion group, patients had significantly greater blood loss, a longer length of stay, and greater changes in serum hemoglobin than those in the primary THA group (P < 0.05). The operative room time, transfusion volume, calculated blood loss, changes in serum hematocrit, and increased superficial infection (P > 0.05) in the conversion group were greater compared with the primary cohort; however, the difference was not statistically significant. The mean postoperative Harris Hip Scoring System (HHS) of the PBFG group at the one-month follow-up was 81, and the control group had an 82 score. Importantly, subgroup analysis of the PBFG group indicated that there was no significant difference between patients who had prior pedicled vascularized iliac bone flap grafting and pedicled vascularized greater trochanter bone flap grafting (P > 0.05), except for the operative room time (P = 0.032).

CONCLUSION

Hip-sparing surgery of ONFH did not make THA more difficult or lead to more peri-operative complications, but increased blood loss and extended hospital stay from a prior PBFG are still notable problems in clinical practice. Thus, it is necessary for surgeons to focus attention on the improvement of the preoperative condition and prepare for any specific intraoperative challenges.

Conservative Treatment in Avascular Necrosis of the Femoral Head: A Systematic Review

INTRODUCTION

Avascular necrosis (AVN) of the femoral head is a pressing orthopedic issue, leading to bone tissue death due to disrupted blood supply and affecting the quality of life of individuals significantly. This review focuses on conservative treatments, evaluating their efficacy as mainstay therapies. Enhanced understanding of AVN's pathophysiology and advancements in diagnostic tools have rekindled interest in non-surgical interventions, emphasizing personalized, multidisciplinary approaches for improved outcomes.

MATERIAL AND METHOD

A systematic search was conducted on PubMed, SCOPUS, and Google Scholar databases from January 2020 to August 2023, with the objective of focusing on conservative treatments for AVN of the femoral head. Eligible studies, including original research, case reports, and observational studies, were examined for relevant, well-documented patient outcomes post-conservative treatments, excluding non-English and surgically focused articles without comparative conservative data.

RESULTS

A systematic search yielded 376 records on AVN of the femoral head across multiple databases. After de-duplication and rigorous screening for relevance and quality, 11 full-text articles were ultimately included for a comprehensive qualitative synthesis, focusing on conservatively managing the condition.

CONCLUSIONS

This review evaluates the effectiveness of conservative treatments such as pharmacological interventions and physical modalities in managing AVN of the femoral head. Despite promising results in symptom alleviation and disease progression delay, variability in outcomes and methodological limitations in studies necessitate further rigorous, randomized controlled trials for a robust, patient-centric approach to optimize therapeutic outcomes in AVN management.

Genetic predisposition of BMP7 polymorphisms to lumbar disk herniation in the Chinese Han population

Bone morphogenetic protein 7 (BMP7) can induce skeletal formation, promote the differentiation of chondrocytes and osteoblasts, and ameliorate intervertebral disc degeneration. The study was designed to evaluate the relationship of BMP7 variants to LDH risk in the Chinese Han population. BMP7 variants were genotyped with the Agena MassARRAY system among 690 LDH patients and 690 healthy controls. The odds ratio (OR) and 95% confidence interval (CI) were calculated by logistic regression. Multi-factor dimension reduction (MDR) (version 3.0.2) software was used to evaluate the effect of BMP7 variant-variant interaction on the susceptibility to LDH. Here, the risk-reducing association between rs230189 and LDH occurrence was found (p = 0.005, OR = 0.79). Specially, rs230189 was associated with decreased LDH risk in females (p = 0.001, OR = 0.60), elder group (p = 0.025, OR = 0.76), subjects with BMI < 24 kg/m2 (p = 0.027, OR = 0.48), nonsmokers (p = 0.001, OR = 0.66), and nondrinkers (p = 0.011, OR = 0.72). Moreover, rs1321862 might be the risk factor for LDH susceptibility among the participants with BMI < 24 kg/m2 (p = 0.024, OR = 1.84). MDR results displayed that rs230189 was the greatest attribution factor on LDH risk in the single-locus model, with an information gain of 0.44%. The present study demonstrated that BMP7 rs230189 g.55771443A>C may play a protective role against LDH risk. Our findings may help to understand the potential mechanism of BMP7 in LDH susceptibility.

Application of Biomaterials in Treating Early Osteonecrosis of the Femoral Head: Research Progress and Future Perspectives

Osteonecrosis of the femoral head (ONFH), a progressive pathological process of femoral head ischemia and osteocyte necrosis, is a refractory orthopedic disease caused by multiple etiologies and there is no complete cure at present. With the extension of ONFH duration, osteocyte apoptosis and trabecular bone loss can decrease the load-bearing capacity of the femoral head, which leads to the collapse of the articular cartilage and subchondral bone. Therefore, an urgent clinical need exists to develop effective treatment strategies of early-stage ONFH for maintaining the hip joint function and preventing femoral head collapse. In recent years, extensive attention has been paid to the application of diverse biomaterials in treating early ONFH for sustaining the normal morphology and function of the autologous femoral head, and slowing disease progression. Herein, we review the research progress of bone grafts, metallic materials, bioceramics, bioglasses and polymer materials for early ONFH treatment, and discuss the biological mechanisms of bone repair and regeneration in the femoral-head necrotic area. We propose suggestions for future research directions, from a special perspective of improving the local microenvironment in femoral head by facilitating vessel-associated osteoclasts (VAOs) generation and coupling of bone-specific angiogenesis and osteogenesis, as well as inhibiting bone-associated osteoclasts (BAOs) and BAO-mediated bone resorption. This review can provide ideas for the research, development, and clinical application of biomaterials for treating early ONFH. STATEMENT OF SIGNIFICANCE: We believe that at least three aspects of this manuscript make it interesting to readers of the Acta Biomaterialia. First, we briefly summarize the incidence, pathogenesis, risk factors, classification criteria and treatment of early osteonecrosis of the femoral head (ONFH). Second, we review the research progress in biomaterials for early ONFH treatment and the biological mechanisms of bone repair and regeneration in femoral-head necrotic area. Third, we propose future research progress on improving the local microenvironment in femoral head by facilitating vessel-associated osteoclasts generation and coupling of bone-specific angiogenesis and osteogenesis, as well as inhibiting bone-associated osteoclasts and bone resorption. We hope this review can provide ideas for the research, development, and clinical application of biomaterials for treating early ONFH.

Multiple Drilling with Recombinant Human Bone Morphogenetic Protein-2 in Korean Patients with Non-Traumatic Osteonecrosis of the Femoral Head: A Prospective Randomized Pilot Study with a Minimum Two-Year Follow-Up

We sought to determine whether multiple drilling (MD) combined with the injection of recombinant human bone morphogenetic protein-2 (rhBMP-2) and β-tricalcium phosphate (β-TCP) could improve survival of the femoral head in pre-collapse lesions of non-traumatic osteonecrosis of the femoral head (ONFH) as compared with MD alone. We conducted a single-site, off-label, comparative and prospective cohort study between November 2017 and May 2019. We enrolled 25 hips (25 patients) with non-traumatic ONFH (Ficat–Arlet stage 2A or less). We performed a survival analysis, and the primary outcome was the occurrence of femoral head collapse on follow-up radiograph. Our cohort consisted of 11 men and 9 women of age 52.5 ± 8.8 years and a body mass index of 24.3 ± 3.0 kg/m². The femoral heads were preserved in 9 hips (45.0%) and collapsed in 11 hips (55.0%) at the final follow-up; mean survival to collapse was 6.9 (range 2.8–13.5) months. There were no significant differences in the survival of the femoral head between the MD alone group and the MD with rhBMP-2 and β-TCP group (five hips survived, 50% vs. four hips survived, 40%, respectively; p = 0.83). MD combined with the injection of rhBMP-2 and β-TCP did not improve femoral head survival compared to MD alone in the pre-collapse non-traumatic ONFH lesion.

Clinical Outcome of Surgical Hip Dislocation Combined with Impacting Bone Grafts and Implanting Iliac Bone Flaps in the Treatment of Osteonecrosis of the Femoral Head: A Mid-term Retrospective Study

Objective

To report the medium‐term outcomes of surgical hip dislocation (SHD) combined with impacting bone grafts and implanting iliac bone flaps in the treatment of osteonecrosis of the femoral head (ONFH) and to define the indications for this treatment.

Methods

This was a single‐center retrospective study. In total, 64 patients (70 hips) with ONFH treated from January 2014 to December 2017 were included in this study. There were 51 males and 13 females aged 18–55 years with an average age of 32 years. All patients underwent surgery for SHD combined with impacting bone grafts and implanting iliac bone flaps. Preoperative and postoperative clinical outcomes were assessed. The clinical outcome was assessed using the Harris hip score (HHS) and the conversion rate of total hip arthroplasty (THA). Univariate and multivariate logistic regression analyses were performed to identify risk factors affecting the clinical outcome. Kaplan–Meier (K‐M) analysis was applied to calculate the survival rate of the femoral head.

Results

At the last follow‐up (60 ± 15.08 months), the HHS was excellent for 41 hips, good for 17 hips, fair for three hips, and poor for nine hips. All nine hips with poor HHS underwent THA, including five in the first 2 years following the index surgery and four between three and 5 years. The conversion rate of total hip arthroplasty was 12.86%. Univariate and multivariate logistic regression analyses showed that the duration of hip pain and JIC classification type were significantly associated with clinical outcomes. Elderly age and advanced ONFH stage tended to lead to worse surgical outcomes. The overall survival rate of JIC classification type C1 and duration of pain ≤6 months was 98.1% and 97.8% at 72 months, respectively, as estimated by the Kaplan–Meier method.

Conclusion

Surgical hip dislocation combined with impacting bone grafts and implanting iliac bone flaps in the treatment of ONFH had a good mid‐term clinical outcome, especially for patients with retention of the lateral column of the femoral head and hip pain less than 1 year.

Tissue Engineering Strategies for Treating Avascular Necrosis of the Femoral Head

Avascular necrosis (AVN) of the femoral head commonly leads to symptomatic osteoarthritis of the hip. In older patients, hip replacement is a viable option that restores the hip biomechanics and improves pain but in pediatric, adolescent, and young adult patients hip replacements impose significant activity limitations and the need for multiple revision surgeries with increasing risk of complication. Early detection of AVN requires a high level of suspicion as diagnostic techniques such as X-rays are not sensitive in the early stages of the disease. There are multiple etiologies that can lead to this disease. In the pediatric and adolescent population, trauma is a commonly recognized cause of AVN. The understanding of the pathophysiology of the disease is limited, adding to the challenge of devising a clinically effective treatment strategy. Surgical techniques to prevent progression of the disease and avoid total hip replacement include core decompression, vascular grafts, and use of bone-marrow derived stem cells with or without adjuncts, such as bisphosphonates and bone morphogenetic protein (BMP), all of which are partially effective only in the very early stages of the disease. Further, these strategies often only improve pain and range of motion in the short-term in some patients and do not predictably prevent progression of the disease. Tissue engineering strategies with the combined use of biomaterials, stem cells and growth factors offer a potential strategy to avoid metallic implants and surgery. Structural, bioactive biomaterial platforms could help in stabilizing the femoral head while inducing osteogenic differentiation to regenerate bone and provide angiogenic cues to concomitantly recover vasculature in the femoral head. Moreover, injectable systems that can be delivered using a minimal invasive procedure and provide mechanical support the collapsing femoral head could potentially alleviate the need for surgical interventions in the future. The present review describes the limitations of existing surgical methods and the recent advances in tissue engineering that are leading in the direction of a clinically effective, translational solution for AVN in future.

High sodium chloride affects BMP-7 and 1α-hydroxylase levels through NCC and CLC-5 in NRK-52E cells

A diet high in sodium chloride (NaCl) can affect renal function damage and increase urinary calcium excretion, leading to bone loss. in renal tubules, Na-Cl co-transporter (NCC) and chloride channel 5 (CLC-5) are involved in regulating urinary calcium excretion. In addition, some cytokines, such as Bone morphogenetic protein 7 (BMP-7) and 1α-hydroxylase, are synthesized by renal tubules, which target on bone and play important roles on bone metabolism. However, the specific mechanisms between NaCl and these ion channels or cytokines still need investigations from many aspects. This study, in culture normal rat renal tubular epithelial NRK-52E cells, showed that high concentrations of NaCl significantly inhibited the cell viability and increased the cell apoptosis. High concentration of NaCl reduce bone mineral density (BMD), as demonstrated by the significantly increased mRNA and protein levels of NCC and osteopontin (OPN), but decreased the levels of CLC-5, BMP-7, and 1α-hydroxylase. In addition, we found that ovariectomized (OVX) rats on a high-salt diet for 12 weeks had altered levels of these indices in the renal cortices. Moreover, the BMD in fourth and fifth lumbar vertebra (LV4 and 5) and femurs were significantly decreased and bone microstructure was destroyed of these rats. We also demonstrated that high concentration of NaCl enhanced the inhibition of these cytokines which is beneficial to increase BMD, induced by modulating ion channels NCC and CLC-5. In conclusion, our results indicate that high concentration of NaCl reduce BMD by regulating ion channels NCC and CLC-5.

Hip preserving procedures for osteonecrosis of the femoral head after collapse

Osteonecrosis of the femoral head (ONFH) affects mainly young patients and causes secondary hip osteoarthritis if remains untreated. Several operative treatments have been introduced with successful outcomes in the early stages. However, in late stages of ONFH treatment may be challenging due to the progressive nature of disease and many surgeons prefer arthroplasty option after collapse. Considering the size, age and etiology an effort should be made to preserve hip joint selected patients with early collapse or minimal arthritic changes. The purpose of the current review is to discuss the results of joint preserving procedures for late stages of ONFH.

Recombinant human FGF-2 for the treatment of early-stage osteonecrosis of the femoral head: TRION, a single-arm, multicenter, Phase II trial

Aim: This study aimed to evaluate the 2-year outcomes from a clinical trial of recombinant human FGF-2 (rhFGF-2) for osteonecrosis of the femoral head (ONFH). Patients & methods: Sixty-four patients with nontraumatic, precollapse and large ONFHs were percutaneously administered with 800 μg rhFGF-2 contained in gelatin hydrogel. Setting the end point of radiological collapse, we analyzed the joint preservation period of the historical control. Changes in two validated clinical scores, bone regeneration and safety were evaluated. Results: Radiological joint preservation time was significantly higher in the rhFGF-2 group than in the control group. The ONFHs tended to improve to smaller ONFHs. The postoperative clinical scores significantly improved. Thirteen serious adverse events showed recovery. Conclusion: rhFGF-2 treatment increases joint preservation time with clinical efficacy, radiological bone regeneration and safety.

Treatment of aseptic osteonecrosis of the femoral head: Historical aspects

The treatment of aseptic osteonecrosis (ON) of the femoral head has been the subject of numerous therapeutic and surgical proposals due to the absence of medical treatment with proven efficacy. For many years, the goal of surgical treatment was to avoid total hip replacement (THR) with uncertain survival in patients considered too young (30-50 years) for this procedure. Numerous conservative treatments were thus proposed: core decompression with numerous variants, non-vascularized and vascularized bone grafts, intertrochanteric and rotational transtrochanteric osteotomies, cementing. The lack of a common classification and a lack of knowledge of natural history complicated the interpretation of the results for a long time. Nevertheless, it appeared that these treatments were effective only in the very early stages and among these in the limited ONs, medial rather than central and especially lateral, with discrepancies according to etiologies apart from sickle cell disease recognized by all as being pejorative. For the same reason, partial arthroplasties have been attempted and abandoned in turn: femoral head total and partial resurfacing and femoral prosthesis. The most recent advances are stem-cell-enhanced core decompression and progress in total arthroplasty, whose reliability has made it possible to extend the indications to increasingly younger patients seeking treatment with guaranteed or near-guaranteed efficacy. Most of the other interventions have disappeared or almost disappeared because of their lack of effectiveness especially in extensive and post-fracture ONs, sometimes because of their complexity and the length of their post-operative management, and also because they complicate and penalize a future total arthroplasty. This argues for early detection of ON at an early stage where the "head can be saved" by stem cell augmented core decompression, a minimally invasive treatment that leaves the chances of success of a THR intact.

Japanese Orthopaedic Association 2019 Guidelines for osteonecrosis of the femoral head

PURPOSE

The Clinical Practice Guidelines for Osteonecrosis of the Femoral Head (ONFH) 2019 Edition, written by the working group for ONFH guidelines of the Japanese Investigation Committee (JIC) for ONFH under the auspices of the Japanese Ministry of Health, Labour, and Welfare and endorsed by the Japanese Orthopaedic Association, were published in Japanese in October 2019. The objective of this guideline is to provide a support tool for decision-making between doctors and patients.

METHODS

Procedures for developing this guideline were based on the Medical Information Network Distribution Service Handbook for Clinical Practice Guideline Development 2014, which proposed an appropriate method for preparing clinical guidelines in Japan.

RESULTS

This clinical practice guideline consists of 7 chapters: epidemiology; pathology; diagnosis; conservative therapy; surgical treatment: bone transplantation/cell therapy; surgical treatment: osteotomy; and surgical treatment: hip replacement. Twelve background questions and 13 clinical questions were determined to define the basic features of the disease and to be addressed when deciding treatment in daily practice, respectively.

CONCLUSIONS

The clinical practice guidelines for the ONFH 2019 edition will be useful for physicians, investigators, and medical staff in clinical practice, as well as for patients, during the decision-making process when defining how to treat ONFH.

Recombinant human FGF-2 therapy for osteonecrosis of the femoral head: 5-year follow-up

Aim: To evaluate the 5-year outcomes from the prospective study of recombinant human FGF-2 (rhFGF-2) for osteonecrosis of the femoral head (ONFH). Methods: Ten patients (average age 39.8 years) with nontraumatic, precollapse ONFH were percutaneously administered with 800 μg rhFGF-2 contained in gelatin hydrogel. Radiological changes and the prevalidated Harris hip score (HHS), visual analogue scale for pain and University of California, Los Angeles activity-rating scale scoring systems were evaluated. Results: The 5-year comparison in type C2 showed higher joint preservation in the rhFGF-2 group (71.4%) than in the natural course group (15.4%). Two of three clinical scores (Harris hip score and visual analogue scale for pain) improved significantly. Postoperative MRI demonstrated significant reduction in ONFH size. There were no adverse events. Conclusion: rhFGF-2 treatment for ONFH appears to be safe and effective and may have the potential to prevent disease progression.

High Pelvic Incidence Is Associated with Disease Progression in Nontraumatic Osteonecrosis of the Femoral Head

BACKGROUND

Although several factors exacerbate osteonecrosis of the femoral head (ONFH), little is known about whether pelvic sagittal parameters are associated with a greater risk of ONFH progression.

QUESTIONS/PURPOSES

The purpose of this study was to investigate the association between pelvic sagittal parameters and disease progression (collapse of the femoral head) in patients with nontraumatic ONFH.

METHODS

From March 2010 through December 2016, we saw 401 patients with unilateral ONFH diagnosed at an outpatient clinic using plain radiography and MRI that were retrospectively reviewed. Of those, 276 patients met our inclusion criteria: Association Research Circulation Osseous (ARCO) Stage I or II nontraumatic unilateral ONFH without femoral head collapse, older than 18 years, and no prior surgical treatment. In all, 74% (203 of 276) of hips had complete follow-up (clinical and radiographic) at a minimum of 2 years. The pelvic sagittal parameters (pelvic incidence, pelvic tilt, and sacral slope) of all patients were measured with standing radiographs by two observers. Progression of disease and potential collapse of the femoral head of all patients (ARCO Stage ≥ III) was examined using radiography every 2 to 3 months after the first outpatient clinic visit. If patients with intractable pain associated with collapse of the femoral head did not respond to nonoperative treatment, THA was performed during the follow-up period. The patients were divided into two groups for comparison: those whose femoral head collapsed within 12 months (rapid progression group) and those whose femoral head did not collapse (nonrapid progression group). The rapid progression group consisted of 49 men and 55 women with a mean age of 55 years; the nonrapid progression group consisted of 60 men and 39 women with a mean age of 56 years. Factors such as age, sex, BMI, size of necrotic lesions, location of necrosis, necrosis risk factor associated with the rapid progression of disease were analyzed using an exploratory univariate analysis followed by a multivariate analysis.

RESULTS

Pelvic incidence (53° ± 9° versus 49° ± 7°; p < 0.01) and sacral slope (38° ± 9° versus 33° ± 7°; p < 0.01) were greater in the rapid progression group than in the non-rapid progression group. After accounting for potentially confounding variables like age, sex, BMI, size of necrotic lesions, location of necrosis, and necrosis risk factors, the only variable we found that was independently associated with more rapid disease progression was high (> 55°) pelvic incidence (odds ratio, 0.95 [95% CI 0.91 to 0.99]; p = 0.03).

CONCLUSIONS

After controlling for potential confounders such as age, sex, BMI, size of necrotic lesions, location of necrosis, and necrosis risk factors, we found that a high pelvic incidence was associated with a greater likelihood of femoral head collapse in patients with nontraumatic ONFH. Assessing pelvic sagittal parameters in patients with early nontraumatic ONFH may help anticipate which patients are at risk for femoral head collapse, but future prospective studies are needed to confirm these findings.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Efficacy of orthobiologic adjuvants to core decompression for hip preservation in avascular necrosis hip

Head preserving modalities in avascular necrosis (AVN) hip are variably effective in early stages, and further options that could prevent head distortion and osteoarthritis are needed. Core decompression (CD) is the most commonly used surgery in the early stages of osteonecrosis with variable rates of success. The present review aimed to determine the effectiveness of bone marrow aspirate concentrate (BMAC), platelet-rich plasma (PRP), bone morphogenetic proteins (BMP) or their combination with CD in early stages of AVN hip, prior to collapse of femoral head. Additionally, any newer unexplored modalities were also searched for and ascertained. PubMed and SCOPUS databases were searched for relevant articles in English language describing CD with aforementioned orthobiologics. We analysed a total of 20 studies published between 2011 and 2020. There were 6 retrospective and 14 prospective studies. PRP showed improved survival and functional outcomes; however, with only three studies, there is inconclusive evidence for its routine utilization. BMAC enhances the efficacy of CD which can further be increased by culture and expansion of cells or combining it with PRP to stimulate growth. In conclusion, CD with BMAC works more efficiently than CD alone prior to collapse of femoral head in AVN. However, PRP needs more evidence for extensive application. Addition of PRP to BMAC or culturing the latter could further enhance the potency of CD + BMAC combination. Very limited data is available for the efficacy of BMP-7 and the role of intraosseous bisphosphonates should be evaluated for a cheaper and potential alternative.

Fibula allograft propping as an effective treatment for early-stage osteonecrosis of the femoral head: a systematic review

BACKGROUND

Osteonecrosis of the femoral head (ONFH) causes severe hip dysfunction. Left untreated, 80% of patients experience femoral head collapse, and 65-70% of patients require total hip arthroplasty (THA). Therefore, effective treatment is very important for ONFH.

OBJECTIVE

To examine the effectiveness of fibula allografting for the treatment of early-stage ONFH METHODS: A systematic review was conducted by searching PubMed, EMBASE, and Web of Science databases using "avascular necrosis" or "ischemic necrosis" or "osteonecrosis" and "femoral head" and "fibula*," and checking the references of primary articles and reviews. Two independent authors completed the study selection separately. We extracted the following details from each article: characteristics of the patients, clinical efficacy evaluation (Harris hip score [HSS], radiographic outcomes, the rate of conversation to total hip arthroplasty [THA], and adverse effects).

RESULTS

A total of 213 articles were selected from PubMed (n = 45), EMBASE (n = 77), Web of Science (n = 203), and other sources (n = 10). After checking the articles, five articles were included in the final analysis. The average age of patients involved in this review was 34.48 years. The studies investigated fibula allografts to treat ONFH in 394 hips with a mean follow-up of 49.06 months. HHS was improved from 62.73 to 86.94. Radiographic progression was found in 33.66% of hips. The failure rate of head-saving surgery by THA was 14.5%. No patients had serious postoperative complications.

LIMITATIONS

The number of articles included in the study was small, and all studies were single-center studies. Most studies were retrospective with a low level of evidence. Surgical procedures were not identical with different follow-up times.

CONCLUSION

Although there are some limitations to our approach, this systematic review supports fibula allografting as a simple, effective treatment for early-stage ONFH, which presents less postoperative complications, and has a satisfactory clinical effect. We consider it to be worthy of promotion as a therapy for ONFH.

Platelet-Rich Plasma-Incorporated Autologous Granular Bone Grafts Improve Outcomes of Post-Traumatic Osteonecrosis of the Femoral Head

BACKGROUND

To investigate the effects of platelet-rich plasma (PRP)-incorporated autologous granular bone grafts for treatment in the precollapse stages (Association of Research Circulation Osseous stage II-III) of posttraumatic osteonecrosis of the femoral head.

METHODS

A total of 46 patients were eligible and enrolled in the study. Twenty-four patients were treated with core decompression and PRP-incorporated autologous granular bone grafting (treatment group), and 22 patients were treated with core decompression and autologous granular bone grafting (control group). During a minimum follow-up duration of 36 months, X-ray and computed tomography were used to evaluate the radiological results, and the Harris hip score (HHS) and visual analog scale were chosen to assess the clinical results.

RESULTS

Both the treatment and control groups had a significantly improved HHS (P < .001). The minimum clinically important difference for the HHS was reached in 91.7% of the treatment group and 68.2% of the control group (P < .05). The HHS and visual analog scale in the treatment group were significantly improved than that in the control group at the last follow-up (P < .05). Successful clinical and radiological results were achieved 87.5% and 79.2% in the treatment group compared with 59.1% and 50.0% in the control group (P < .05), respectively. The survival rates based on the requirement for further hip surgery as an endpoint were higher in the treatment group in comparison to those in the control group (P < .05).

CONCLUSION

PRP-incorporated autologous granular bone grafting is a safe and effective procedure for treatment in the precollapse stages (Association of Research Circulation Osseous stage II-III) of posttraumatic osteonecrosis of the femoral head.

Joint-preserving procedures for osteonecrosis of the femoral head

Osteonecrosis of the femoral head is a poorly understood condition that may lead to progressive destruction of the hip joint. Its incidence is common between the third and fifth decades of life and it is the diagnosis behind 5–18% of annually performed total hip arthroplasties (THAs) in the USA.

Regarding the high rate of complications of THA in that age group, authors have agreed on the importance of joint-preservation techniques for this disease but techniques vary to establish a generally accepted algorithmic approach.

Surgical head-preserving procedures, core decompression with or without graft, stem cell augmentation, or biologic adjuncts, vascularized bone grafting, and proximal femoral osteotomies have all been published on with heterogeneous results and with limited evidence to date.

Consensus states that the prognosis of patients with osteonecrosis of the femoral head can be significantly improved with early diagnosis and timely intervention.

Cite this article: EFORT Open Rev 2019;4:647-658. DOI: 10.1302/2058-5241.4.180073

Clinical application of injectable growth factor for bone regeneration: a systematic review

Bone regeneration has been the ultimate goal in the field of bone and joint medicine and has been evaluated through various basic research studies to date. Translational research of regenerative medicine has focused on three primary approaches, which are expected to increase in popularity: cell therapy, proteins, and artificial materials. Among these, the local injection of a gelatin hydrogel impregnated with the protein fibroblast growth factor (FGF)-2 is a biomaterial technique that has been developed in Japan. We have previously reported the efficacy of gelatin hydrogel containing injectable FGF-2 for the regenerative treatment of osteonecrosis of the femoral head. Injectable growth factors will probably be developed in the future and gain popularity as a medical approach in various fields as well as orthopedics. Several clinical trials have already been conducted and have focused on this technique, reporting its efficacy and safety. To date, reports of the clinical application of FGF-2 in revascularization for critical limb ischemia, treatment of periodontal disease, early bone union for lower limb fracture and knee osteotomy, and bone regeneration for osteonecrosis of the femoral head have been based on basic research conducted in Japan. In the present report, we present an extensive review of clinical applications using injectable growth factors and discuss the associated efficacy and safety of their administration.

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.

Effect of leg-length discrepancy following total hip arthroplasty on collapse of the contralateral hip in bilateral non-traumatic osteonecrosis of the femoral head

AIMS

The purpose of this study was to examine whether leg-length discrepancy (LLD) following unilateral total hip arthroplasty (THA) affects the incidence of contralateral head collapse and subsequent THA in patients with bilateral osteonecrosis, and to determine factors associated with subsequent collapse.

PATIENTS AND METHODS

We identified 121 patients with bilateral non-traumatic osteonecrosis who underwent THA between 2003 and 2011 to treat a symptomatic hip, and who also exhibited medium-to-large lesions (necrotic area ≥ 30%) in an otherwise asymptomatic non-operated hip. Of the 121 patients, 71 were male (59%) and 50 were female (41%), with a mean age of 51 years (19 to 71) at the time of initial THA. All patients were followed for at least five years and were assessed according to the presence of a LLD (non-LLD vs LLD group), as well as the LLD type (longer non-operated side vs shorter non-operated side group).

RESULTS

Overall, 68 hips (56%) became painful and progressed to collapse at a mean of 2.6 years (0.2 to 13.8), resulting in 59 THAs (49%). The five-year collapse-free survival rate for the non-LLD group was 59% (95% confidence interval (CI) 46.8 to 71.8) compared with 45% (95% CI 32.9 to 57.5) for the LLD group (p = 0.036), and 66% (95% CI 55.2 to 77.2) for the longer non-operated side group compared with 32% (95% CI 19.1 to 44.9) for the shorter non-operated side group (p < 0.001). Multivariate regression analyses found that large lesions had a higher risk of collapse than medium-size lesions (odds ratio (OR) 4.19, 95% confidence interval (CI) 1.69 to 10.38; p = 0.002). Meanwhile, patients with a LLD < 3 mm (OR 0.20, 95% CI 0.08 to 0.52; p = 0.001) or a longer non-operated leg (OR 0.11, 95% CI 0.04 to 0.28; p < 0.001) after THA were less likely to experience a subsequent collapse.

CONCLUSION

We found that LLD may be a modifiable risk factor for femoral head collapse. Minimizing LLD and particularly avoiding a shorter non-operated limb after THA may lead to a lower risk of collapse of the asymptomatic hip in patients with bilateral non-traumatic osteonecrosis. Cite this article: Bone Joint J 2019;101-B:303-310.

Vascular endothelial growth factor for the treatment of femoral head osteonecrosis: An experimental study in canines

AIM

To evaluate the treatment of osteonecrosis of the femoral head (ONFH) with the use of vascular endothelial growth factor (VEGF).

METHODS

In 30 mature beagles (6 groups of 5 beagles) ONFH was induced cryosurgically and one of the following solutions was administered locally in the femoral head (FH) in each group: Single injection of 500 μg VEGF (t-VEGFμ group); single injection of 500 ng VEGF (t-VEGFn group); continuous delivery of 500 μg VEGF through osmotic micropump (t-VEGFpump-μ group); continuous delivery of 500 ng VEGF through osmotic micropump (t-VEGFpump-n group); single injection of 0.9% sodium chloride (t-NS group), while one group that served as control group did not receive any local solution (No-t group). FHs were retrieved 12 wk postoperatively, underwent decalcification and hematoxylin/eosin and toluidine blue staining. In two canines per group, one half of FH was processed without decalcification and stained with modified Masson Trichrome. Histological sections were observed by light microscopy and measured with a semi-automatized bone histomorphometry system and Bone Volume/Total Volume (BV/TV), Marrow Volume/Total Volume (MaV/TV), and Trabecular Thickness (TbTh) were assessed. Standard and robust tests (Welch, Brown Forsythe) of analysis of variance along with multiple comparisons, were carried out among the categories.

RESULTS

The untreated (No-t) group had signs of osteonecrosis, whereas the VEGF groups revealed reversal of the osteonecrosis. Statistical analysis of the decalcified specimens revealed a significantly better BV/TV ratio and a higher TbTh between the VEGF treatment groups (except the t-VEGFn group) and the No-t group or the control t-NS group. Single dose 500 μgVEGF group had significantly better BV/TV ratio and higher TbTh when compared to the No-t group (50.45 ± 6.18 vs 29.50 ± 12.27, P = 0.002 and 151.44 ± 19.07 vs 107.77 ± 35.15, P = 0.161 respectively) and the control t-NS group (50.45 ± 6.18 vs 30.9 ± 6.67, P = 0.004 and 151.44 ± 19.07 vs 107.14 ± 35.71, P = 0.151 respectively). Similar differences were found for the prolonged VEGF delivery/pump groups of 500 μg and 500 ng. Analysis of the totality of specimens (decalcified/non-decalcified) enhanced the aforementioned differences and additionally revealed significant differences in the comparison of the TbTh.

CONCLUSION

In an experimental model of ONFH in canines it was found that local treatment with VEGF leads to bone tissue remodeling and new bone formation.

Lantern-shaped screw loaded with autologous bone for treating osteonecrosis of the femoral head

Background

Treatment for osteonecrosis of the femoral head (ONFH) in young individuals remains controversial. We developed a lantern-shaped screw, which was designed to provide mechanical support for the femoral head to prevent its collapse, for the treatment of ONFH. The purpose of this study was to investigate the efficacy and safety of the lantern-shaped screw loaded with autologous bone for the treatment of pre-collapse stages of ONFH.

Methods

Thirty-two patients were randomly divided into two groups: the lantern-shaped screw group (core decompression and lantern-shaped screw loaded with autogenous bone) and the control group (core decompression and autogenous bone graft). During 36 months follow-up after surgery, treatment results in patients were assessed by X-ray and computed tomography (CT) scanning as well as functional recovery Harris hip score (HHS).

Results

Successful clinical results were achieved in 15 of 16 hips (94%) in the lantern-shaped screw group compared with 10 of 16 hips (63%) in the control group (p = 0.0325). Successful radiological results were achieved in 14 of 16 hips (88%) in the lantern-shaped screw group compared with 8 of 16 hips (50%) in the control group (P = 0.0221).

Conclusion

The lantern-shaped screw loaded with autologous bone for the treatment of pre-collapse stages of ONFH is effective and results in preventing progression of ONFH and reducing the risk of femoral head collapse.

Trial registration

The trial registration number: ChiCTR-TRC-13004078 (retrospectively registered at 2013-11-28).

Incidence and Risk Factors for Blood Transfusion in Simultaneous Bilateral Total Joint Arthroplasty: A Multicenter Retrospective Study

BACKGROUND

The aim of this study was to identify the incidence and risk factors for blood transfusion in patients undergoing simultaneous bilateral total hip arthroplasty (SBTHA) and simultaneous bilateral total knee arthroplasty (SBTKA).

METHODS

We identified 414 SBTHA and 1147 SBTKA procedures, and separated the patients into those who did and did not require allogeneic blood transfusion. A multivariate logistic regression model was used to identify independent risk factors for transfusion.

RESULTS

The transfusion rate after SBTHA was 50.0%, and significant risk factors for transfusion were female gender (odds ratio [OR] = 2.612), lower body mass index (OR = 1.093), inflammatory arthritis (OR = 1.970), American Society of Anesthesiologists (ASA) class ≥3 (OR = 3.477), drain use (OR = 4.607), and increased intraoperative bleeding. We also found that higher preoperative hemoglobin (Hb) and tranexamic acid use decreased the risk of transfusion. The transfusion rate after SBTKA was 29.1%, and significant risk factors for transfusion were ASA class ≥3 (OR = 8.959), tourniquet use (OR = 2.129), drain use (OR = 4.970), and increased intraoperative bleeding. A higher preoperative Hb was the only protective factor for transfusion.

CONCLUSION

For SBTHA, the risk factors included female gender, lower body mass index, inflammatory arthritis, ASA class ≥3, drain use, and increased intraoperative bleeding, while for SBTKA, risk factors were ASA class ≥3, tourniquet use, drain use, and increased intraoperative bleeding. Increasing the preoperative Hb level may decrease transfusion risk. In addition, tranexamic acid was encouraged to use to decrease transfusion need in SBTHA.

Surgical accuracy, function, and quality of life of simultaneous versus staged bilateral Total hip Arthroplasty in patients with Osteonecrosis of the femoral head

BACKGROUND

The optimal surgical option for patients requiring bilateral hip replacement remains controversial. The purpose of this study was to compare surgical accuracy; functional outcome and health-related quality of life; and prosthetic-related complications and revision surgery of a simultaneous bilateral total hip arthroplasty (THA) with those of a staged bilateral THA with an interval between procedures <12 months.

METHODS

A total of 123 unselected consecutive patients (mean age, 43.3 years) who underwent bilateral THAs for osteonecrosis of the femoral head (ONFH) with a minimum follow-up of two years (mean, 60.2 months) were studied retrospectively; 63 simultaneous procedures served as a test group and 60 staged procedures served as a control group.

RESULTS

The mean postoperative leg-length discrepancy (LLD) and the percentage of patients who had an LLD >3 mm were significantly lower in the simultaneous group (P < 0.001 and P = 0.001, respectively). A higher number of cups within the safe zones, a higher correction rate, and a lower failure rate for the cup placement in the second-operated hip were also identified in the simultaneous group. The mean Harris hip score, EuroQol-5D index, and EuroQol-visual analogue scale score were all better in the simultaneous group at the latest follow-up (P < 0.001, in all comparisons). We found that the simultaneous procedure was associated with a lower incidence of postoperative prosthetic-related complications and revision surgery.

CONCLUSIONS

We suggest that bilateral ONFH could be treated with a simultaneous THA rather than a staged THA to achieve a better surgical outcome.

Clinical application of bone morphogenetic proteins for bone healing: a systematic review

PURPOSE

This paper documents the existing evidence on bone morphogenetic proteins (BMPs) use for the treatment of bone fractures, non-union, and osteonecrosis, through a review of the clinical literature, underlying potential and limitations in terms of cost effectiveness and risk of complications.

METHODS

A systematic review was performed on the PubMed database using the following string: (bone morphogenetic proteins OR BMPs) and (bone repair OR bone regeneration) including papers from 2000 to 2016. The search focused on clinical trials dealing with BMPs application to favor bone regeneration in bone fractures, non-union, and osteonecrosis, in English language, with level of evidence I, II, III, and IV. Relevant data (type of study, number of patients, BMPs delivery material, dose, site, follow-up, outcome, and adverse events) were extracted and analyzed.

RESULTS

Forty-four articles met the inclusion criteria: 10 randomized controlled trials (RCTs), 7 comparative studies, 18 case series, and 9 case reports. rhBMP-2 was documented mainly for the treatment of fractures, and rhBMP-7 mainly for non-unions and osteonecrosis. Mixed results were found among RCTs and comparative papers: 11 reported positive results for BMPs augmentation, 3 obtained no significant effects, and 2 showed negative results. The only study comparing the two BMPs showed a better outcome with rhBMP-2 for non-union treatment.

CONCLUSION

Clinical evidence on BMPs use for the treatment of fractures, non-union, and osteonecrosis is still controversial, with the few available reports being mainly of low quality. While positive findings have been described in many studies, mixed results are still present in the literature in terms of efficacy and adverse events. The difficulties in drawing clear conclusions are also due to the studies heterogeneity, mainly in terms of different BMPs applied, with different concomitant treatments for each bone pathology. Therefore, further research with well-designed studies is needed in order to understand the real potential of this biological approach to favour bone healing.

Heterotopic ossification after the use of recombinant human bone morphogenetic protein-7

AIM

To present the incidence of heterotopic ossification after the use of recombinant human bone morphogenetic protein-7 (rhBMP-7) for the treatment of nonunions.

METHODS

Bone morphogenetic proteins (BMPs) promote bone formation by auto-induction. Recombinant human BMP-7 in combination with bone grafts was used in 84 patients for the treatment of long bone nonunions. All patients were evaluated radiographicaly for the development of heterotopic ossification during the standard assessment for the nonunion healing. In all patients (80.9%) with radiographic signs of heterotopic ossification, a CT scan was performed. Nonunion site palpation and ROM evaluation of the adjacent joints were also carried out. Factors related to the patient (age, gender), the nonunion (location, size, chronicity, number of previous procedures, infection, surrounding tissues condition) and the surgical procedure (graft and fixation type, amount of rhBMP-7) were correlated with the development of heterotopic ossification and statistical analysis with Pearsons χ² test was performed.

RESULTS

Eighty point nine percent of the nonunions treated with rhBMP-7, healed with no need for further procedures. Heterotopic bone formation occurred in 15 of 84 patients (17.8%) and it was apparent in the routine radiological evaluation of the nonunion site, in a mean time of 5.5 mo after the rhBMP-7 application (range 3-12). The heterotopic ossification was located at the femur in 8 cases, at the tibia in 6, and at the humerus in οne patient. In 4 patients a palpable mass was present and only in one patient, with a para-articular knee nonunion treated with rhBMP-7, the size of heterotopic ossification affected the knee range of motion. All the patients with heterotopic ossification were male. Statistical analysis proved that patient’s gender was the only important factor for the development of heterotopic ossification (P = 0.007).

CONCLUSION

Heterotopic ossification after the use of rhBMP-7 in nonunions was common but it did not compromise the final clinical outcome in most cases, and affected only male patients.

The 'Hip Vacuum Sign'-a new radiographic phenomenon in femoro-acetabular impingement

Femoro-acetabular impingement (FAI) is a frequent cause for groin pain in young and active patients. We discovered a so far undescribed radiographic phenomenon only visible in frog-leg lateral radiographs. The aim of this study was to describe this new radiological sign, to determine its prevalence in a symptomatic population and to investigate the correlation to a potential underlying pathology. We retrospectively reviewed all patients, who had been sent to our clinic between 2010 and 2012 for hip complaints. We excluded patients older than 50 years and patients with advanced osteoarthritis. Two independent investigators blinded to clinical data independently examined all images for the presence, location and dimension of a vacuum phenomenon and a potential underlying hip pathology. We included 242 patients. 137 of them showed clinical and radiological signs of FAI. A hip vacuum phenomenon was identified in 20 of 242 patients (8%). Interestingly, all these patients showed distinct signs of femoro-acetabular impingement. In reference to this, the prevalence of the "Hip Vacuum Sign" was 15% (20/137) in symptomatic patients with FAI. There was no correlation with age or gender. We identified a new radiological sign, the "Hip Vacuum Sign", in 15% of symptomatic patients with FAI. It was only visible in frog-leg lateral radiographs. We suggest that it represents a subluxation of the femoral head due to a lever mechanism between the femoral neck and the acetabular rim and is, therefore, a hint for a relevant femoro-acetabular impingement mechanism.

Bone morphogenetic protein-2 provokes interleukin-18-induced human intervertebral disc degeneration

OBJECTIVES

Interleukin 18 (IL-18) is a regulatory cytokine that degrades the disc matrix. Bone morphogenetic protein-2 (BMP-2) stimulates synthesis of the disc extracellular matrix. However, the combined effects of BMP-2 and IL-18 on human intervertebral disc degeneration have not previously been reported. The aim of this study was to investigate the effects of the anabolic cytokine BMP-2 and the catabolic cytokine IL-18 on human nucleus pulposus (NP) and annulus fibrosus (AF) cells and, therefore, to identify potential therapeutic and clinical benefits of recombinant human (rh)BMP-2 in intervertebral disc degeneration.

METHODS

Levels of IL-18 were measured in the blood of patients with intervertebral disc degenerative disease and in control patients. Human NP and AF cells were cultured in a NP cell medium and treated with IL-18 or IL-18 plus BMP-2. mRNA levels of target genes were measured by real-time polymerase chain reaction, and protein levels of aggrecan, type II collagen, SOX6, and matrix metalloproteinase 13 (MMP13) were assessed by western blot analysis.

RESULTS

The serum level of patients (IL-18) increased significantly with the grade of IVD degeneration. There was a dramatic alteration in IL-18 level between the advanced degeneration (Grade III to V) group and the normal group (p = 0.008) Furthermore, IL-18 induced upregulation of the catabolic regulator MMP13 and downregulation of the anabolic regulators aggrecan, type II collagen, and SOX6 at 24 hours, contributing to degradation of disc matrix enzymes. However, BMP-2 antagonised the IL-18 induced upregulation of aggrecan, type II collagen, and SOX6, resulting in reversal of IL-18 mediated disc degeneration.

CONCLUSIONS

BMP-2 is anti-catabolic in human NP and AF cells, and its effects are partially mediated through provocation of the catabolic effect of IL-18. These findings indicate that BMP-2 may be a unique therapeutic option for prevention and reversal of disc degeneration.Cite this article: S. Ye, B. Ju, H. Wang, K-B. Lee. Bone morphogenetic protein-2 provokes interleukin-18-induced human intervertebral disc degeneration. Bone Joint Res 2016;5:412-418. DOI: 10.1302/2046-3758.59.BJR-2016-0032.R1.

Joint-preserving regenerative therapy for patients with early-stage osteonecrosis of the femoral head

Osteonecrosis of the femoral head is an intractable disease often occurring in patients aged 30–40 years that can cause femoral head collapse, pain, and gait disturbance. Background factors, including corticosteroid use, alcohol intake, and idiopathic causes, have been indicated. It is estimated that 70–80 % of osteonecrosis patients experience femoral head collapse, for which total hip arthroplasty is considered the most effective treatment, even in young patients. Thus, there is a crucial need for developing a minimally invasive regenerative therapy as a preventive surgery for femoral head collapse: this has been an important area of research in the past decades. Core decompression, the most popular minimally invasive surgery for osteonecrosis of the femoral head, has been used for a long time; however, it has been insufficient to prevent femoral head collapse. For further improvement in therapeutic efficacy, cell transplantation and the use of artificial bone and growth factors have been proposed in addition to core decompression. Since 2000, newer therapies such as autologous bone marrow cell transplantation and the embedding of metal implant rods have been developed in Europe and the USA; however, these approaches have yet to become a global standard. This practical review summarizes applied state-of-the-art regenerative therapy-based core decompression. We introduce the clinical application of recombinant human fibroblast growth factor (rhFGF)-2-impregnated gelatin hydrogel for patients with precollapse osteonecrosis of the femoral head. Radiography and computed tomography have confirmed bone regeneration inside the femoral heads around the region of rhFGF-2 gelatin hydrogel administration. With further development, the minimally invasive method, which can be expected to promote bone regeneration in necrotic areas, could become a useful early-stage treatment for osteonecrosis of the femoral head. Patients can resume their daily routine soon after surgery, and the procedure is inexpensive. As such, it is a promising regenerative therapy that can be actively employed in osteonecrosis of the femoral head before femoral head collapse.

Roles of the kidney in the formation, remodeling and repair of bone

The relationship between the kidney and bone is highly complex, and the kidney plays an important role in the regulation of bone development and metabolism. The kidney is the major organ involved in the regulation of calcium and phosphate homeostasis, which is essential for bone mineralization and development. Many substances synthesized by the kidney, such as 1,25(OH)2D3, Klotho, bone morphogenetic protein-7, and erythropoietin, are involved in different stages of bone formation, remodeling and repair. In addition, some cytokines which can be affected by the kidney, such as osteoprotegerin, sclerostin, fibroblast growth factor -23 and parathyroid hormone, also play important roles in bone metabolism. In this paper, we summarize the possible effects of these kidney-related cytokines on bone and their possible mechanisms. Most of these cytokines can interact with one another, constituting an intricate network between the kidney and bone. Therefore, kidney diseases should be considered among patients presenting with osteodystrophy and disturbances in bone and mineral metabolism, and treatment for renal dysfunction may accelerate their recovery.

RhBMP-7 for the treatment of nonunion of fractures of long bones

We report the outcome of 84 nonunions involving long bones which were treated with rhBMP-7, in 84 patients (60 men: 24 women) with a mean age 46 years (18 to 81) between 2003 and 2011. The patients had undergone a mean of three previous operations (one to 11) for nonunion which had been present for a mean of 17 months (4 months to 20 years). The nonunions involved the lower limb in 71 patients and the remainder involved the upper limb. A total of 30 nonunions were septic. Treatment was considered successful when the nonunion healed without additional procedures. The relationship between successful union and the time to union was investigated and various factors including age and gender, the nature of the nonunion (location, size, type, chronicity, previous procedures, infection, the condition of the soft tissues) and type of index procedure (revision of fixation, type of graft, amount of rhBMP-7) were analysed. The improvement of the patients' quality of life was estimated using the Short Form (SF) 12 score. A total of 68 nonunions (80.9%) healed with no need for further procedures at a mean of 5.4 months (3 to 10) post-operatively. Multivariate logistic regression analysis of the factors affecting union suggested that only infection significantly affected the rate of union (p = 0.004).Time to union was only affected by the number of previous failed procedures (p = 0.006). An improvement of 79% and 32.2% in SF-12 physical and mental score, respectively, was noted within the first post-operative year. Rh-BMP-7 combined with bone grafts, enabled healing of the nonunion and improved quality of life in about 80% of patients. Aseptic nonunions were much more likely to unite than septic ones. The number of previous failed operations significantly delayed the time to union.

The role of orthobiologics in hip preservation surgery

The potential regenerative role of different orthobiologics is becoming more recognized for the treatment of chronic and degenerative musculoskeletal conditions. Over the last few years there has been an increasing number of publications on cell therapy and other orthobiologics for the treatment of avascular necrosis of the femoral head and other hip conditions with promising short–term clinical results. In this article, we have used a systematic search of the literature to identify potentially relevant topics on orthobiologics and then selected those most applicable to hip preservation surgery. We identified several innovative strategies and present a summary of the currently available evidence on their potential role in hip preservation surgery. For many of these treatment strategies there was a lack of clinical evidence and therefore we suggest that there is a need for comparative studies in this field.

A current review of non-vascularized bone grafting in osteonecrosis of the femoral head

Over the past three decades, non-vascularized bone grafts have been demonstrated to be viable treatments for pre- and early post-collapse osteonecrosis of the femoral head; however, there are limited reviews on this topic. Therefore, the purposes of this review are to (1) provide a summary of the different surgical techniques and their respective clinical outcomes and (2) evaluate new adjunct therapies. Originally, non-vascularized bone grafting was performed using the Phemister technique with varying results. More recently, newer techniques such as the lightbulb and trapdoor are used to place non-vascularized bone grafts with excellent results. The addition of various biological agents has demonstrated positive results; however, further studies are needed to confirm the best appropriate indications and to elucidate long-term results.

Conservative surgery for the treatment of osteonecrosis of the femoral head: current options

The prevention of femoral head collapse and the maintenance of hip function would represent a substantial achievement in the treatment of osteonecrosis of the femoral head; however it is difficult to identify appropriate treatment protocols to manage patients with pre-collapse avascular necrosis in order to obtain a successful outcome in joint preserving procedures. Conservative treatments, including pharmacological management and biophysical modalities, are not supported by any evidence and require further investigation. The appropriate therapeutic approach has not been identified. The choice of surgical procedures is based on patient clinical conditions and anatomopathological features; preservation of the femoral head by core decompression may be attempted in younger patients without head collapse. Biological factors, such as bone morphogenetic proteins and bone marrow stem cells, would improve the outcome of core decompression. Another surgical procedure proposed for the treatment of avascular necrosis consists of large vascularized cortical bone grafts, but its use is not yet common due to surgical technical issues. Use of other surgical technique, such as osteotomies, is controversial, since arthroplasty is considered as the first option in case of severe femoral head collapse without previous intervention.

Management of femoral head osteonecrosis: Current concepts

Osteonecrosis of femoral head (ONFH) is a disabling condition of young individuals with ill-defined etiology and pathogenesis. Remains untreated, about 70-80% of the patients progress to secondary hip arthritis. Both operative and nonoperative treatments have been described with variable success rate. Early diagnosis and treatment is the key for success in preserving the hip joint. Once femoral head collapses (>2 mm) or if there is secondary degeneration, hip conservation procedures become ineffective and arthroplasty remains the only better option. We reviewed 157 studies that evaluate different treatment modalities of ONFH and then a final consensus on treatment was made.