Evidence for using bisphosphonate to treat Legg-Calvé-Perthes disease

Epidemiology, natural evolution, pathogenesis, clinical spectrum, and management of Legg-Calvé-Perthes

Background

Legg-Calvé-Perthes disease is a self-limiting disorder that develops in children following interruption of the blood supply to the capital femoral epiphysis. This review outlines the current knowledge on the epidemiology, natural evolution, clinical spectrum, and management of the disease.

Methods

The literature pertaining to these aspects of the disease were studied and summarized in this review.

Results

Epidemiological studies suggest that environmental factors contribute to the causation of the disease. Incidence rates monitored over time indicate that the incidence of Legg-Calvé-Perthes disease is declining. The natural evolution followed on sequential plain radiographs enables division of the disease into Stages Ia, Ib, IIa, IIb, IIIa, IIIb, and IV. Reversible deformation of the capital occurs in Stages Ia-IIa simply on standing while irreversible deformation may occur in Stages IIb and IIIa. Treatment of Legg-Calvé-Perthes disease in Stages Ia-IIa aims to prevent the femoral head from getting deformed by containment and avoidance of weight-bearing. In Stages IIb and IIIa, treatment aims to remedy the effects of early irreversible deformation of the femoral head. In Stage IIIb and IV, treatment is directed to correcting the altered shape of the femoral head. The impression that these treatment methods are helpful is based on poor quality evidence.

Conclusion

There is an urgent need to undertake Level I studies to establish the efficacy of currently treatment.

Level of evidence

level V.

[Juvenile osteochondrosis and osteonecrosis]

BACKGROUND

Juvenile osteonecrosis is an important topic in orthopedics. A wide variety of body regions of the growing patient are affected, predominantly during adolescence. All are characterized by a usually unknown aetiology as well as a stadium-like course. The main problem is a local osseous circulatory disorder, which causes osteonecrosis.

RISK FACTORS

Mechanical overloading due to increased body weight, axial misalignment, and sports activity is discussed as a risk factor. Healing depends on the localization and extent of the osseous necrosis.

DIAGNOSTICS

Diagnostically, radiologic imaging is used, in which the typical bony remodeling can be followed.

THERAPY

The therapeutic procedure depends on the affected region but is usually accompanied by a reduction of mechanical loading. If the clinical and radiological findings worsen, surgical treatment must be considered. The recognition and treatment of juvenile osteonecrosis is important and significantly influences the further development of the patient.

Effects of zoledronic acid on osteonecrosis and acute lymphoblastic leukemia treatment efficacy in preclinical models

BACKGROUND

Osteonecrosis is a devastating side effect of acute lymphoblastic leukemia (ALL) therapy. Associations between bone density loss and osteonecrosis have sparked interest in using bisphosphonates to reduce this complication.

PROCEDURE

We assessed the impact of zoledronic acid (ZA) on the development of osteonecrosis in murine models when used either throughout therapy (continuous administration) or late in therapy after vascular lesions have developed but before osteonecrosis has occurred. Effects on bone density were measured using microcomputed tomography (μCT)-assessed tibial cortical thickness, while osteonecrosis was assessed histologically in the distal femur. Effects on antileukemic efficacy of chemotherapy were evaluated in both immunocompetent/syngeneic and patient-derived xenograft (PDX) models.

RESULTS

Continuous administration of ZA with chemotherapy prevented chemotherapy-associated bone loss (p < .001) and reduced osteonecrosis (p = .048). Late initiation of ZA diminished bone loss (p < .001) but had no impact on the development of osteonecrosis (p = .93). In the immunocompetent murine ALL model, mice treated with ZA and chemotherapy succumbed to leukemia sooner than mice treated with chemotherapy alone (p = .046). Analysis using PDX showed a nonsignificant decrease in survival with ZA (p = .17).

CONCLUSION

Our data indicate ZA may prevent osteonecrosis if begun with chemotherapy but showed no benefit when administered later in therapy. However, ZA may also reduce the antileukemic efficacy of chemotherapy.

Antiresorptive treatment and talar collapse after displaced fractures of the talar neck: a long-term follow-up of 19 patients

Background and purpose - Displaced fractures of the talar neck are associated with a high risk of structural collapse. In this observational analysis we hypothesized that pharmacological inhibition of osteoclast function might reduce the risk of structural collapse through a reduction in bone resorption during revascularization of the injured bone.Patients and methods - Between 2002 and 2014 we treated 19 patients with displaced fractures of the talar neck with open reduction and internal fixation. Of these, 16 patients were available for final follow-up between January and November 2017 (median 12 years, IQR 7-13). Among these, 6 patients with Hawkins type 3 fractures and 2 patients with Hawkins type 2b fractures received postoperative antiresorptive treatment (7 alendronate, 1 denosumab) for 6 to 12 months. The remaining 8 patients received no antiresorptive treatment. The self-reported foot and ankle score (SEFAS) was available in all patients and 15 patients had undergone computed tomography (CT) at final follow-up, which allowed evaluation of structural collapse of the talar dome and signs of post-traumatic osteoarthritis.Results - The risk for partial collapse of the talar dome was equal in the 2 groups (3 in each group) and post-traumatic arthritis was observed in all patients. The SEFAS in patients with antiresorptive treatment was lower, at 21 points (95% CI 15-26), compared with those without treatment, 29 points (CI 22-35).Interpretation - Following a displaced fracture of the talar neck, we found no effect of antiresorptive therapy on the rate of talar collapse, post-traumatic osteoarthritis, and patient-reported outcomes.

Analysis of Bone Microarchitectural Changes and Structural Damage in Sickle Cell Disease-Induced Avascular Necrosis Using Raman Spectroscopy: Is there potential for medical management?

Objectives

Bone failure due to avascular necrosis (AVN) is a complex pathological phenomenon. Analysis of molecular changes in the bone matrix may help to shed light on the disease process and guide management. This study aimed to explore changes in bone quality and structural damage caused by sickle cell disease (SCD)-induced AVN using Raman spectroscopy.

Methods

A total of 10 necrotic femoral heads were obtained from seven SCD patients who underwent total hip replacements. The femoral heads were cut in half and scanned using Raman spectroscopy in correlation with preoperative magnetic resonance imaging to identify necrotic and healthy control areas. Subsequently, samples were examined to determine changes in bone mineralisation, crystallinity, carbonate content, collagen cross-linking and mineral and collagen fibril orientation.

Results

Significant changes were observed in bone mineral content, mineral-to-organic content and collagen fibril orientation in necrotic compared to control areas (P ≤0.050).

Conclusion

The necrotic samples displayed severe structural damage and loss of mineral and organic contents. Similar Raman signals have been reported in other metabolic bone diseases such as osteoporosis, thereby potentially supporting the use of medical treatment in AVN to promote bone quality.

Osteoblasts/Osteocytes sirtuin6 Is Vital to Preventing Ischemic Osteonecrosis Through Targeting VDR-RANKL Signaling

Ischemic osteonecrosis (ION) can produce permanent deformity and osteoarthritis in the femoral head and other joints. No biologic treatment has been established, and the molecular mechanisms involved in the pathogenesis of ION have not been elucidated. In this work, we found that treatment with sirtuin6 (Sirt6) suppressed inflammatory cytokines, bone resorption, progression of osteoarthritis, and reduced bone deformity in an ION mouse model. We used a deacetylase mutant adenovirus to confirm that those effects were caused by the deacetylase function of Sirt6. Among the osteoclastogenic factors of osteoblasts, only the receptor activator of NF-κb ligand (RANKL) level changed in response to Sirt6 knockout in primary osteoblasts. In particular, the vitamin D receptor physically interacted with Sirt6 and induced recruitment of Sirt6 around RANKL promoters. Finally, Tg mice overexpressing Sirt6 resisted osteocyte death, bone resorption, and progression of osteoarthritis after ischemic surgery, whereas osteoblast/osteocyte-specific Sirt6 knockout mice showed aggravated bone loss and severe deformity. Our findings demonstrate that administration of Sirt6 prevents bone loss and osteoarthritis in ischemic conditions. Activation of Sirt6 in osteoblasts/osteocytes could be a new therapeutic approach to treating ION of the femoral head and other bone regions. © 2020 American Society for Bone and Mineral Research (ASBMR).

Severe bilateral Legg-Calvé-Perthes resolved with pamidronate in combination with casts, physiotherapy and adductor tenotomy: a pictorial essay over 11 years

We describe an 11-year prospective clinical and radiologic course of a 6-year-old boy with bilateral Legg-Calvé-Perthes disease, who was treated with intravenous pamidronate (IV-PAM). His baseline radiographs showed grade IV avascular necrosis/Catterall stage IV, and at worst he progressed to lateral pillar/Herring stage C bilaterally. His disease initially was extremely functionally limiting with expected poor outcome with eventual joint replacement. Because IV-PAM stops bone breakdown and allows for ongoing bone formation while revascularisation of bone occurs, we hypothesised that IV-PAM could act as an adjunct to traditional treatment to help heal the femoral heads. Our patient received nine once monthly doses of IV-PAM (1 mg/kg/dose) over 13 months, along with Petrie/broomstick casts and physiotherapy. Remarkably, over time, his femoral heads healed. Now, at 11-year follow-up, he has excellent functional and radiologic outcome with congruence between femoral head and acetabulum, no residual osteonecrosis and minimal loss of femoral head sphericity.

Effects of Zoledronic Acid and Vitamin E on Surgical- Induced Osteonecrosis of the Femoral Head in Rabbit

BACKGROUND

Femoral head osteonecrosis is a progressive disease with disabling outcomes in hip joint if not treated. This study was designed to compare the effects of zoledronic acid plus vitamin E versus zoledronic acid alone in surgical induced femoral head osteonecrosis in rabbits.

METHODS

26 Japanese white adult normal male rabbits at 28-32 weeks old were undertaken surgical femoral dislocation to devastate the femoral neck vessels; the femoral neck vessels were ligated and the hip was relocated. Next, the first 10 rabbits received zoledronic acid injections at 1^st and the 4^th weeks; the second group (10 rabbits) received zoledronic acid injections at 1^st and the 4^th week along with daily oral vitamin E for 12 weeks; and the third group was considered as non-treated control group. Radiographic and postmortem pathological assessments including the Ficat classification, epiphyseal quotient (EQ), new bone formation, and residual necrotic bone (RNB) were performed and compared after week 12.

RESULTS

A significant difference was found between the combination therapy group and the control group in Ficat classification at 12^th weeks (P=0.048), but, the difference between monotherapy and combination therapy groups at 12^th weeks was nonsignificant (P=0.37). Also, both treated groups had significant difference with the control group for RNB (P=0.015). There were no significant differences between the three groups for Ficat classification at the 6^th week (P=0.65); EQ at 6^th (P=0.59) and 12^th week (P=0.64); and NBF (P=0.55).

CONCLUSION

Although zoledronic acid therapy along with vitamin E could improve some radiologic and pathological indices related to femoral head osteonecrosis, vitamin E showed a relative impact.

LEVEL OF EVIDENCE

I.

Drilling Combined with Adipose-derived Stem Cells and Bone Morphogenetic Protein-2 to Treat Femoral Head Epiphyseal Necrosis in Juvenile Rabbits

This study was designed to evaluate the effects of drilling through the growth plate and using adipose-derived stem cells (ADSCs) and bone morphogenetic protein-2 (BMP-2) to treat femoral head epiphyseal ischemic necrosis, which can be done in juvenile rabbits. Passagefour bromodeoxyuridine (BrdU)-labeled ADSCs were cultured, assayed with MTT to determine their viability and stained with alizarin red dye to determine their osteogenic ability. Two-month-old, healthy male rabbits (1.2 to 1.4 kg, n=45) underwent ischemic induction and were randomly divided into five groups (group A: animal model control; group B: drilling; group C: drilling & ADSCs; group D: drilling & BMP-2; and group E: drilling & ADSCs & BMP-2). Magnetic resonance imaging (MRI), X-ray imaging, hematoxylin and eosin staining and BrdU immunofluorescence detection were applied 4, 6 and 10 weeks after treatment. Approximately 90% of the ADSCs were labeled with BrdU and showed good viability and osteogenic ability. Similar results were observed in the rabbits in groups C and E at weeks 6 and 10. The animals of groups C and E demonstrated normal hip structure and improved femoral epiphyseal quotients and trabecular areas compared with those of the groups A and B (P<0.01). Group D demonstrated improved femoral epiphyseal quotients and trabecular areas compared with those of groups A and B (P<0.05). In summary, drilling through the growth plate combined with ADSC and BMP-2 treatments induced new bone formation and protected the femoral head epiphysis from collapsing in a juvenile rabbit model of femoral head epiphyseal ischemic necrosis.

Material properties of bone in the femoral head treated with ibandronate and BMP-2 following ischemic osteonecrosis

Bone morphogenetic protein (BMP)-2 and ibandronate (IB) decrease the femoral head deformity following ischemic osteonecrosis of the femoral head (ONFH). The purpose of this study was to determine the effects of BMP-2 and IB on the mineral content and nanoindentation properties of the bone following ONFH. ONFH was surgically induced in the femoral head of piglets. There were five groups: normal control, untreated, IB, BMP, and BMP + IB (n = 5/group). Backscattered electron imaging, Raman spectroscopy, and nanoindentation testing were performed. Both BMP and BMP + IB groups showed calcium content in the trabecular bone similar to the normal group, while the IB and no-treatment groups showed a significant increase in the calcium content compared to the normal group. The carbonate content relative to phosphate was significantly increased in the IB and BMP + IB groups (p < 0.01) compared to the normal group. No significant difference was found between the BMP and the normal group. The nanoindentation modulus of the bone in the IB group was significantly increased compared to the normal group (p < 0.05). No significant differences were observed between the BMP and BMP + IB groups compared to the normal group. The nanoindentation hardness measurements in the IB group were also significantly increased compared to the BMP and BMP + IB groups (p < 0.05). In summary, trabecular bone treated with BMP or BMP + IB had material properties comparable to normal bone whereas the bone in the IB group retained the increased mineral content and the nanoindentation hardness found in the necrotic bone. Hence, BMP or BMP + IB better restores the normal mineral content and nanomechanical properties after ONFH than IB treatment alone. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1453-1460, 2017.

Protocol for a randomised control trial of bisphosphonate (zoledronic acid) treatment in childhood femoral head avascular necrosis due to Perthes disease

INTRODUCTION

Perthes disease (PD) is an idiopathic disorder presenting with avascular necrosis to the femoral head, which frequently results in flattening. Long-term function is directly related to the subsequent femoral head sphericity. Current treatment includes mechanical modalities and surgical procedures, which are therapeutic but are not uniformly able to prevent collapse. The use of the nitrogen-containing bisphosphonate zoledronic acid (ZA) to inhibit osteoclastic bone resorption is aimed at preserving femoral head strength, reducing collapse and thus maintaining shape. The proposed multicentre, prospective, randomised controlled trial intends to evaluate the efficacy of ZA treatment in PD.

METHODS AND ANALYSIS

An open-label randomised control trial recruiting 100 children (50 each treatment arm) 5 to 16 years old with unilateral PD. Subjects are randomly assigned to either (a) ZA and standard care or (b) Standard care. The primary outcome measure is deformity index (DI), a radiographic parameter of femoral head roundness assessed at 24 months, following 12 months of ZA treatment (3-monthly doses of ZA 0.025 mg/kg at baseline, 3, 6, 9 and 12 months) plus 12 months observation (group A) or 24 months of observation (group B). Secondary outcome measures are femoral head subluxation, Faces Pain scale, Harris hip score and quality of life. Assessments are made at baseline, 3 monthly during the first year of follow-up and then 6 monthly, until the 24th month.

ETHICS AND DISSEMINATION

The study commenced following the written approval from the Human Research Ethics Committee. Safety considerations regarding the effects of ZA are monitored which include the subject's symptomatology, mineral status, bone mass and turnover activity, and metaphyseal modelling. Data handling plan requires that all documents, clinical information, biological samples and investigation results will be held in strict confidence by study investigators to preserve its safety and confidentiality.

TRIAL REGISTRATION NUMBER

Australian and New Zealand Clinical Trials ACTRN12610000407099, pre-results.

Targeted delivery to bone and mineral deposits using bisphosphonate ligands

The high concentration of mineral present in bone and pathological calcifications is unique compared with all other tissues and thus provides opportunity for targeted delivery of pharmaceutical drugs, including radiosensitizers and imaging probes. Targeted delivery enables accumulation of a high local dose of a therapeutic or imaging contrast agent to diseased bone or pathological calcifications. Bisphosphonates (BPs) are the most widely utilized bone-targeting ligand due to exhibiting high binding affinity to hydroxyapatite mineral. BPs can be conjugated to an agent that would otherwise have little or no affinity for the sites of interest. This article summarizes the current state of knowledge and practice for the use of BPs as ligands for targeted delivery to bone and mineral deposits. The clinical history of BPs is briefly summarized to emphasize the success of these molecules as therapeutics for metabolic bone diseases. Mechanisms of binding and the relative binding affinity of various BPs to bone mineral are introduced, including common methods for measuring binding affinity in vitro and in vivo. Current research is highlighted for the use of BP ligands for targeted delivery of BP conjugates in various applications, including (1) therapeutic drug delivery for metabolic bone diseases, bone cancer, other bone diseases, and engineered drug delivery platforms; (2) imaging probes for scintigraphy, fluorescence, positron emission tomography, magnetic resonance imaging, and computed tomography; and (3) radiotherapy. Last, and perhaps most importantly, key structure-function relationships are considered for the design of drugs with BP ligands, including the tether length between the BP and drug, the size of the drug, the number of BP ligands per drug, cleavable tethers between the BP and drug, and conjugation schemes.

Current perspectives on the pediatric hip: selected topics in hip dysplasia, Perthes disease, and chondrolysis: synopsis of the hip subspecialty session at the POSNA Annual Meeting, May 1, 2013, Toronto

The following are proceedings from the Hip Breakout Session held at the 2013 annual meeting of the Pediatric Orthopaedic Society of North America in Toronto, Canada. The organizer's goal of the meeting was to gather experts with years of clinical experience to discuss topics based upon both experience and current clinical evidence. The topics that were selected represented the most commonly encountered pathology where there are wide variations of clinical practice. The invited speakers were asked to summarize both their clinical experience and the current scientific evidence and to summarize areas that require further scientific investigation.

Comparison of core decompression and conservative treatment for avascular necrosis of femoral head at early stage: a meta-analysis

The purpose of the current meta-analysis was to compare the efficacy of core decompression (CD) and conservative treatment (CT) for saving femoral heads in patients with avascular necrosis of femoral head (ANFH). Four RCTs and two CCTs involving 323 hips with 24- to 48-months follow-up were included in this review. Our results suggested CD had a trend of favorable results in contrast to other CT (OR 3.28; 95% CI 0.77-14.02; P = 0.11) but saved much less hips compared to biophysical treatments [odds ratio (OR) 0.37; 95% CI 0.18-0.74; P = 0.005]. In the stratified survival rate analysis by ANFH stage, interestingly, CD group got a significantly higher successful rate of hip joint conservation than other CT group in both stage I and stage II-III (stage I: OR 4.43; 95% CI 1.34-14.65; P = 0.01; stage II-III: OR 6.75; 95% CI 2.18-20.90; P = 0.0009). In the biophysical stimulation subgroup, however, an even higher frequency of survived hips were observed compared to CD group at stage II-III (CD vs. biophysical stimulation: OR 0.34; 95% CI 0.17-0.67; P = 0.002). In conclusion, performing CD for ANFH is effective for preventing femoral collapse within a short-term follow-up, but an even higher successful rate were expected by biophysical stimulations. Nevertheless, the short-term follow-up, the small sample size of the current meta-analysis only provide limited quality of evidence, which required confirmation from further large-scale, well-designed RCT with longer follow-up.

Evidence for using alendronate to treat adult avascular necrosis of the femoral head: a systematic review

Osteonecrosis or avascular osteonecrosis (AVN) of the femoral head is a devastating multifactorial disease that affects 20 000 persons each year in the United States. The purpose of this systematic review was to determine the efficacy and safety of alendronate for adult AVN during short- and long-term follow-up. Electronic databases were searched for randomized or nonrandomized clinical trials, cohort, case-control studies, and series of cases in which alendronate was used for treatment of adult AVN of the femoral head. Relevant articles with adequate data on reduction of pain, improvement of articular function, slowing of bone collapse progression, or need for total hip arthroplasty (THA) were included after applying inclusion and exclusion criteria. Eight articles involving 788 hips with evidence level 1b to 3b were included in this systematic review. Most studies suggested a positive short-term efficacy of alendronate treatment in reducing pain, improving articular function, slowing of bone collapse progression, and delaying the need for THA for adult AVN patients. The favorable long-term results were also presented in those treated patients after 10-year follow-up. In addition, there were no severe adverse effects associated with alendronate treatment observed during short- and long-term follow-up, and most of the included studies suggested use of alendronate in early AVN with small necrotic lesion to achieve better outcomes. The findings support consideration of alendronate use for adult AVN, particularly with early stage and small necrotic size. The lack of large-scale, randomized, and double-blind studies justifies new studies to demonstrate the detailed indication and the optimized strategy of alendronate treatment. Level of evidence: Level 3a.

Efficacy of alendronate for preventing collapse of femoral head in adult patients with nontraumatic osteonecrosis

The purpose of the current review was to determine the efficacy of alendronate for preventing collapse of femoral head in adult patients with nontraumatic avascular osteonecrosis of femoral head (ANFH). Five randomized controlled trials (RCTs) involving 305 hips were included in this review, of which 3 studies investigated alendronate versus control/placebo and the other 2 studies compared the combination of alendronate and extracorporeal shockwave therapy (ESWT) with ESWT alone. Our results suggested that even the patients with extensive necrosis encountered much less collapse in the alendronate group than control group. In these RCTs, their data also indicated a positive short- and middle-term efficacy of alendronate treatment in joint function improvement and hip pain diminishment. With the presence of the outlier study, only insignificant overall efficacy of alendronate could be observed with substantial heterogeneities. In addition, we did not find any additive benefits of alendronate in combination with ESWT for preventing collapse compared to ESWT alone. In conclusion, there is still lack of strong evidence for supporting application of alendronate in adult patients with nontraumatic ANFH, which justified that large scale, randomized, and double-blind studies should be developed to demonstrate the confirmed efficacies, detailed indication, and optimized strategy of alendronate treatment.

Local delivery of recombinant human bone morphogenetic proteins and bisphosphonate via sucrose acetate isobutyrate can prevent femoral head collapse in Legg-Calve-Perthes disease: a pilot study in pigs

PURPOSE

Legg-Calve-Perthes disease is a paediatric condition encompassing idiopathic osteonecrosis of the femoral head (ONFH). Preventing collapse and the need for subsequent joint replacement remains the major goal of clinical management. This exploratory study utilises a porcine model of surgically induced ONFH.

METHODS

rhBMP-2 with and without zoledronic acid (ZA) was delivered by intra-osseous injection in the phase-transitioning sucrose acetate isobutyrate (SAIB) in an attempt to prevent femoral head collapse. Epiphyseal quotient (EQ) at eight weeks post-surgery was the primary outcome measure. Heterotopic ossification in the joint capsule and bisphosphonate retention in the femoral head were key secondary outcomes.

RESULTS

Femoral heads with ONFH and no treatment all collapsed (3/3, EQ < 0.4, P < 0.05 compared to no ONFH). Local delivery of rhBMP-2/SAIB into the femoral head prevented collapse by EQ measurement one of four samples; however, this specimen still showed evidence of significant collapse. In contrast, the combination of local rhBMP-2 and local ZA prevented collapse in two of four samples. Confocal fluorescence microscopy showed locally dosed bisphosphonate entered and was retained in the femoral head. This group also showed strong Calcein signal, indicating new bone formation. Treatment with rhBMP-2 was associated with a limited amount of heterotrophic ossification in the joint capsules in some specimens.

CONCLUSIONS

Operators reported SAIB to be an efficient way to deliver rhBMP-2 to the femoral head. These data suggest that rhBMP-2 is ineffective for preventing femoral head collapse without the addition of bisphosphonate. Further research will be required to validate the clinical efficacy of a combined local rhBMP-2/bisphosphonate approach.