PEMF as treatment for delayed healing of foot and ankle arthrodesis

Extracorporal shock wave therapy for the treatment of arthrodesis non-unions

INTRODUCTION

Non-union is a regular complication of arthrodeses. Standard treatment includes revision surgery with frequent need for re-revision due to persistent non-union. Particularly patients with concomitant diseases are at risk of secondary complications. There is a need for evaluation of alternative treatment options. The aim of this study is to provide first evidence on union-rate and pain course after focussed extracorporeal shock-wave therapy of arthrodesis non-unions.

PATIENTS AND METHODS

In a retrospective single-centre study, 25 patients with non-union following arthrodesis received one session of focussed extracorporeal shock-wave therapy (energy flux density 0.36 mJ/mm², 3000 impulses, 23 kV, 4 Hz). Radiographic and clinical results were recorded 6, 12 and 24 weeks after treatment.

RESULTS

24 patients were followed-up. After 24 weeks arthrodeses of the hand healed in 80%, of the upper ankle in 50%, of subtalar joint in 27.2% and of the midfoot in 0% of the cases. Pain decreased from 4.8 (± 2.8) points on the visual analogue scale to 3.4 (± 2.3), 2.9 (± 2.5) and 2.4 (± 2.8) points after 6, 12 and 24 weeks, respectively (p < 0.0001).

CONCLUSION

Our data indicate that the effect of focussed, high-energy shock wave therapy depends on body region and is effective for the treatment of non-unions of the hand as well as for pain relief.

LEVEL OF EVIDENCE

Level IV.

What Is the Treatment "Algorithm" for Infection After Ankle or Hindfoot Arthrodesis?

RECOMMENDATION

There is no universal algorithm for addressing the infected ankle or subtalar arthrodesis. A potential algorithm created by consensus is.

LEVEL OF EVIDENCE

Consensus.

DELEGATE VOTE

Agree: 100%, Disagree: 0%, Abstain: 0% (Unanimous, Strongest Consensus).

Electrical stimulation-based bone fracture treatment, if it works so well why do not more surgeons use it?

BACKGROUND

Electrical stimulation (EStim) has been proven to promote bone healing in experimental settings and has been used clinically for many years and yet it has not become a mainstream clinical treatment.

METHODS

To better understand this discrepancy we reviewed 72 animal and 69 clinical studies published between 1978 and 2017, and separately asked 161 orthopedic surgeons worldwide about their awareness, experience, and acceptance of EStim for treating fracture patients.

RESULTS

Of the 72 animal studies, 77% reported positive outcomes, and the most common model, bone, fracture type, and method of administering EStim were dog, tibia, large bone defects, and DC, respectively. Of the 69 clinical studies, 73% reported positive outcomes, and the most common bone treated, fracture type, and method of administration were tibia, delayed/non-unions, and PEMF, respectively. Of the 161 survey respondents, most (73%) were aware of the positive outcomes reported in the literature, yet only 32% used EStim in their patients. The most common fracture they treated was delayed/non-unions, and the greatest problems with EStim were high costs and inconsistent results.

CONCLUSION

Despite their awareness of EStim's pro-fracture healing effects few orthopedic surgeons use it in their patients. Our review of the literature and survey indicate that this is due to confusion in the literature due to the great variation in methods reported, and the inconsistent results associated with this treatment approach. In spite of this surgeons seem to be open to using this treatment if advancements in the technology were able to provide an easy to use, cost-effective method to deliver EStim in their fracture patients.

Ankle Arthrodesis for Talar Avascular Necrosis and Arthrodesis Nonunion

This article reviews the surgical treatment of talar avascular necrosis. Specifically, arthrodesis for this complex entity and potential treatment of nonunions are discussed. The hallmarks of treatment are evolving and can range from nonoperative measures to amputations. Nonoperative treatment and the results of current arthrodesis techniques for late-stage avascular necrosis are reviewed. Surgical correction requires an understanding of the condition's natural history, utilization of structural and nonstructural bone grafting techniques, and stable fixation. Although the methods described follow standard orthopedic principles, high-quality evidence and outcome studies are limited for treatment of this challenging and often disabling condition.

American College of Foot and Ankle Surgeons® Clinical Consensus Statement: Perioperative Management

A wide range of factors contribute to the complexity of the management plan for an individual patient, and it is the surgeon's responsibility to consider the clinical variables and to guide the patient through the perioperative period. In an effort to address a number of important variables, the American College of Foot and Ankle Surgeons convened a panel of experts to derive a clinical consensus statement to address selected issues associated with the perioperative management of foot and ankle surgical patients.

Complex ankle arthrodesis: Review of the literature

Complex ankle arthrodesis is defined as an ankle fusion that is at high risk of delayed and nonunion secondary to patient comorbidities and/or local ankle/hindfoot factors. Risk factors that contribute to defining this group of patients can be divided into systemic factors and local factors pertaining to co-existing ankle or hindfoot pathology. Orthopaedic surgeons should be aware of these risk factors and their association with patients' outcomes after complex ankle fusions. Both external and internal fixations have demonstrated positive outcomes with regards to achieving stable fixation and minimizing infection. Recent innovations in the application of biophysical agents and devices have shown promising results as adjuncts for healing. Both osteoconductive and osteoinductive agents have been effectively utilized as biological adjuncts for bone healing with low complication rates. Devices such as pulsed electromagnetic field bone stimulators, internal direct current stimulators and low-intensity pulsed ultrasound bone stimulators have been associated with faster bone healing and improved outcomes scores when compared with controls. The aim of this review article is to present a comprehensive approach to the management of complex ankle fusions, including the use of biophysical adjuncts for healing and a proposed algorithm for their treatment.

Complex ankle arthrodesis: Review of the literature

Complex ankle arthrodesis is defined as an ankle fusion that is at high risk of delayed and nonunion secondary to patient comorbidities and/or local ankle/hindfoot factors. Risk factors that contribute to defining this group of patients can be divided into systemic factors and local factors pertaining to co-existing ankle or hindfoot pathology. Orthopaedic surgeons should be aware of these risk factors and their association with patients’ outcomes after complex ankle fusions. Both external and internal fixations have demonstrated positive outcomes with regards to achieving stable fixation and minimizing infection. Recent innovations in the application of biophysical agents and devices have shown promising results as adjuncts for healing. Both osteoconductive and osteoinductive agents have been effectively utilized as biological adjuncts for bone healing with low complication rates. Devices such as pulsed electromagnetic field bone stimulators, internal direct current stimulators and low-intensity pulsed ultrasound bone stimulators have been associated with faster bone healing and improved outcomes scores when compared with controls. The aim of this review article is to present a comprehensive approach to the management of complex ankle fusions, including the use of biophysical adjuncts for healing and a proposed algorithm for their treatment.

Pulsed Electromagnetic Field (PEMF) plus BMP-2 upregulates intervertebral disc-cell matrix synthesis more than either BMP-2 alone or PEMF alone

STUDY DESIGN

An in vitro study using human intervertebral disc (IVD) cells.

OBJECTIVES

To determine if pulsed electromagnetic field (PEMF) plus bone morphogenetic protein (BMP)-2 could upregulate IVD-cell matrix synthesis more than either BMP-2 alone or PEMF alone.

SUMMARY OF BACKGROUND DATA

BMP-7 and BMP-2 can both upregulate IVD-cell matrix synthesis. There are problems associated with using either BMP-2 or BMP-7. They can diffuse away rather quickly after injection into the IVD space, they cost a lot, and they have side effects such as soft-tissue inflammation and swelling. PEMF has been reported to stimulate various types of cells. PEMF is safe, inexpensive, and noninvasive, thus multiple use is possible. However, PEMF alone has a rather weak effect on disc cells. We decided to carry out an experiment whereby we combined PEMF with BMP-2. Our thoughts were that BMP-2 plus PEMF could be better than either alone.

METHODS

The PEMF signal used was similar to that used in the clinical treatment of fracture nonunions or delayed fracture healing. Human disc cells were treated with BMP-2 alone or PEMF alone or PEMF plus BMP-2. Quantitative real-time PCR was performed to determine mRNA expression levels of aggrecan, collagen-2, transforming growth factor (TGF)-β, BMP-2, and BMP-7. Sulfated glycosaminoglycansynthesis was analyzed using the dimethylmethylene blue method. Western blot analysis was performed to determine the protein levels of TGF-β, BMP-2, and BMP-7.

RESULTS

PEMF plus BMP-2 upregulates IVD-cell matrix synthesis more than BMP-2 alone or PEMF alone, and the effect seems to be synergistic. Also, PEMF plus BMP-2 induces more endogenous BMP-7 and BMP-2 mRNA levels as well as protein levels, as compared with either PEMF alone or BMP-2 alone.

CONCLUSIONS

PEMF plus BMP-2 acts in synergy to upregulate intervertebral disc-cell matrix synthesis more than either BMP-2 alone or PEMF alone.

Upregulation of intervertebral disc-cell matrix synthesis by pulsed electromagnetic field is mediated by bone morphogenetic proteins

STUDY DESIGN

An in vitro study on the effects of pulsed electromagnetic field (PEMF) on intervertebral disc-cell matrix synthesis.

OBJECTIVES

The objective of the study was to determine whether (1) PEMF can upregulate intervertebral disc-cell matrix synthesis and (2) any upregulation obtained is through transforming growth factor (TGF)-β or bone morphogenetic proteins (BMPs).

SUMMARY OF BACKGROUND DATA

PEMF has been reported to produce cell proliferation, enhance cell function, and upregulate matrix synthesis in cell types such as osteoblasts, chondroblasts, endothelial cells, and fibroblasts through the upregulation of several growth factors. PEMF has been used clinically in the treatment of delayed bone union. However, PEMF has never been tested on human intervertebral disc cells.

METHODS

The PEMF signal used was similar to that used in the clinical treatment of delayed fracture healing. Human disc cells were treated with PEMF for 8 hours per day for 3 days. Quantitative real-time polymerase chain reaction was performed to determine mRNA expression levels of aggrecan, collagen-2, TGF-β, BMP-2, and BMP-7. Sulfated glycosaminoglycan synthesis was analyzed using the dimethylmethylene blue (DMMB) method. Western blot analysis was performed to determine the protein levels of TGF-β, BMP-2, and BMP-7. To determine whether any action of PEMF was through BMP, recombinant human Noggin was used at a dose of 100 ng/mL to block BMP.

RESULTS

PEMF could upregulate intervertebral disc-cell matrix synthesis. BMP-7 was markedly upregulated by PEMF and was upregulated much more than BMP-2. TGF-β was not upregulated by PEMF. The effect of PEMF on disc-cell matrix was entirely inhibited in the presence of Noggin.

CONCLUSIONS

PEMF acts through BMPs to upregulate intervertebral disc-cell matrix synthesis.

Union rate of tibiotalocalcaneal nails with internal or external bone stimulation

INTRODUCTION

The use of bone growth stimulation has been reported in the application of hindfoot and ankle arthrodesis. Most studies have been retrospective case series with few patients. The authors present a comparative analysis of patients undergoing tibiotalocalcaneal (TTC) arthrodesis via a retrograde intramedullary arthrodesis nail to evaluate the influence of internal versus external bone stimulation in this population.

METHODS

One hundred fifty-four patients were treated with retrograde intramedullary nailing. A comprehensive chart and radiographic review was performed from a database of patients who underwent TTC fusion with or without bone stimulation. Ninety-one patients with retrograde TTC nailing were treated with direct current internal bone stimulation at the time of the index procedure (internal group) and 63 were treated with combined magnetic field external bone stimulation (external group). The primary end point was fusion with potential variables evaluated for influence on fusion rates.

RESULTS

Demographically the cohorts were similar groups in age and comorbidities. Surgical and outcome data were examined, and there were few statistically significant differences between the two groups. There was no statistically significant difference in rate of union (52.7% and 57.1%, p = .63) or rate of complications between the internal and external groups. Overall, the success rate for achieving a stable, functional limb for the groups was 81.3% (74/91 patients) and 82.5% (52/63 patients) in the internal and external groups, respectively (p = .62).

CONCLUSION

The authors demonstrated there were no statistically significant differences between the union and complication rate when comparing these types of internal and external bone stimulation in this patient population. Consideration of these results may help guide physicians when considering bone stimulation as an adjunct to TTC fusions with a retrograde intramedullary nail.

The slot graft technique for foot and ankle arthrodesis in a high-risk patient group

BACKGROUND

High rates of arthrodesis nonunion have been described in the ankle, hindfoot and midfoot in patients with significant risk factors. The purpose of this study was to evaluate fusion rates, risk of reoperation, postoperative pain scores and patient satisfaction for a slot graft inlay arthrodesis technique used in a high-risk group of foot and ankle patients.

MATERIALS AND METHODS

We retrospectively reviewed all ankle, hindfoot and midfoot arthrodeses by two foot and ankle surgeons in our institution between January 2000 and January 2009. Seventeen arthrodesis procedures in 16 patients using the slot graft technique were identified. Patient charts were reviewed for medical history, risk factors, previous surgery and postoperative complications. Time to union was evaluated on radiographs. Patients provided final followup by phone with an assessment of pain, overall satisfaction and use of orthotic or assistive devices.

RESULTS

Union occurred in 13 arthrodesis procedures (77%) with an average time to union of 5 months. Postoperative infection occurred in one patient. Additional surgery was performed in nine patients. At final followup patients reported low pain scores (3 of 10) and high satisfaction (8 of 10). Fourteen of 15 patients contacted indicated that they would choose to undergo the procedure again.

CONCLUSION

The slot graft arthrodesis technique provided satisfactory results in this small group of patients with a low complication rate. Patient satisfaction rates were high with low pain scores at an average of 62 months postoperatively.

Shock wave therapy as a treatment of nonunions, avascular necrosis, and delayed healing of stress fractures

Shock wave therapy (SWT) stimulates angiogenesis and osteogenesis. SWT is commonly used to treat soft tissue musculoskeletal conditions such as fasciopathies and tendinopathies. Recent basic science and clinical data suggest that SWT can also be used to treat disorders of bone. Nonunions, avascular necrosis, and delayed healing of stress fractures have all been successfully treated with SWT. Success rates with SWT are equal to those with standard surgical treatment, but SWT has the advantage of decreased morbidity. The procedure is safe, well tolerated, yields few complications, and, typically, can be performed on an outpatient basis. SWT is a viable noninvasive alternative to stimulate healing of bone.

Bone and wound healing in the diabetic patient

Impaired soft tissue regeneration and delayed osseous healing are known complications associated with diabetes mellitus with regard to orthopedic surgery, making the management and treatment of diabetic patients undergoing foot and ankle surgery more complex and difficult. At the moment several options are available to address the known issues that complicate the clinical outcomes in these high-risk patients. Using a multifaceted approach, with close attention to intraoperative and perioperative considerations including modification of surgical technique to supplement fixation, local application of orthobiologics, tight glycemic control, administration of supplementary oxygen, and biophysical stimulation via low-intensity pulsed ultrasound and electrical bone stimulation, the impediments associated with diabetic healing can potentially be overcome, to yield improved clinical results for diabetic patients after acute or elective foot and ankle surgery.

Design and implementation of therapeutic ultrasound generating circuit for dental tissue formation and tooth-root healing

Biological tissue healing has recently attracted a great deal of research interest in various medical fields. Trauma to teeth, deep and root caries, and orthodontic treatment can all lead to various degrees of root resorption. In our previous study, we showed that low-intensity pulsed ultrasound (LIPUS) enhances the growth of lower incisor apices and accelerates their rate of eruption in rabbits by inducing dental tissue growth. We also performed clinical studies and demonstrated that LIPUS facilitates the healing of orthodontically induced teeth-root resorption in humans. However, the available LIPUS devices are too large to be used comfortably inside the mouth. In this paper, the design and implementation of a low-power LIPUS generator is presented. The generator is the core of the final intraoral device for preventing tooth root loss and enhancing tooth root tissue healing. The generator consists of a power-supply subsystem, an ultrasonic transducer, an impedance-matching circuit, and an integrated circuit composed of a digital controller circuitry and the associated driver circuit. Most of our efforts focus on the design of the impedance-matching circuit and the integrated system-on-chip circuit. The chip was designed and fabricated using 0.8- ¿m high-voltage technology from Dalsa Semiconductor, Inc. The power supply subsystem and its impedance-matching network are implemented using discrete components. The LIPUS generator was tested and verified to function as designed and is capable of producing ultrasound power up to 100 mW in the vicinity of the transducer's resonance frequency at 1.5 MHz. The power efficiency of the circuitry, excluding the power supply subsystem, is estimated at 70%. The final products will be tailored to the exact size of teeth or biological tissue, which is needed to be used for stimulating dental tissue (dentine and cementum) healing.

Bone growth stimulation for foot and ankle nonunions

During the last few decades, electrical current stimulation has gone from an investigational modality to an accepted method of treatment to assist with bone healing. This article provides an overview of electrical bone stimulation for nonunions in the foot and ankle.

Effects of extremely low-frequency-pulsed electromagnetic field on different-derived osteoblast-like cells

The aim of this study is to investigate the effects of extremely low-frequency pulsed electromagnetic field (PEMF) on osteoblast-like cells. PEMF with a magnetic flux density of 1.55 mT at 48 Hz was employed to stimulate the MC3T3-E1 cell and the primary osteoblast cell derived from 2-day-old Sprague Dawley (SD) rat calvaria for different time. MTS method was applied to analyze cell proliferation and flow cytometry to detect cell cycle. The intracellular alkaline phosphatase (ALP) activity was measured by colorimetry. Our results demonstrated that PEMF of 1.55 mT at 48 Hz did not affect cell number of MC3T3-E1 cell, whereas the cell percentage of S and G(2)M phase decreased significantly. Although the cell number of the primary osteoblast cell did not alter by MTS assay after being exposed to PEMF for 24 h continuously, the cell percentage of S and G(2)M phase increased significantly. When culture time extended to 48 h, the cell number increased greatly and the cell percentage of S and G(2)M phase decreased significantly despite of the exposure type. After the primary osteoblast cell was exposed to PEMF for 24 h continuously, the ALP activity decreased significantly, whereas it increased significantly when being exposed to PEMF for 48 h continuously. From the results we concluded that PEMF of 1.55 mT at 48 Hz did not affect proliferation and differentiation of MC3T3-E1 cell, but it promoted proliferation, inhibited differentiation at proliferation stage, and promoted differentiation at differentiation stage of primary osteoblast cells.

Revisional hindfoot arthrodesis

Salvage of a failed hindfoot arthrodesis is an extensive undertaking for the surgeon and patient. With increased morbidity and postoperative convalescence and complications, patients must understand the risk involved in this type of revisional surgery. This article provides a systematic approach to revisional hindfoot arthrodeses, focusing on patient evaluation, surgical technique, and postoperative treatment.

An approach to the failed ankle arthrodesis

Ankle arthrodesis remains the gold standard of surgical treatment for advanced ankle joint arthritis. Failure can occur as a result of infection, nonunion or malunion, resulting in pain and poor function. This paper offers a systematic approach to preventing, and managing these problems should they occur. Revision arthrodesis performed with a detailed understanding of the appropriate alignment and mechanics of the ankle joint, combined with meticulous attention to understanding and reversing the cause of the failure can result in successful salvage and restoration of function.

Bioadjuvants for complex ankle and hindfoot reconstruction

Many reconstructive options exist for symptomatic hindfoot and ankle problems. Hindfoot and tibiotalar fusions are reliable procedures with consistent results. Unfortunately, many potential complications have been cited throughout the literature. Although the most important aspect in any fusion surgery is meticulous technique, advances in technology, including PRP, bone stimulators, and BMPs seem to be useful additions in the quest to achieve solid fusions with decreased complications.

Electric stimulation and hyperbaric oxygen therapy in the treatment of nonunions

Up to 10% of the fractures occurring annually in the U.S. end up in non-union or delayed union. Classical treatment with osteosynthesis and bone grafting is not always successful. Alternatives in treatment have long ago been considered. This article presents current concepts in treatment with electrical stimulation and hyperbaric oxygen, the mechanisms of action, experimental and clinical evidence of their application.

Electrical bone stimulation: an overview and its use in high risk and Charcot foot and ankle reconstructions

Since early work done in the 1950s on the "piezoelectricity of bone," a growing body of basic science and clinical evidence suggests the use of electrical bone stimulation as an adjunct in the treatment of foot and ankle nonunions, fusions, and Charcot arthropathy. Both implantable designs (that allow for direct constant stimulation of bone) and nonimplantable (such as pulsed and combined electromagnetic fields) devices have been studied. Ongoing research continues to support the potential usefulness of these modalities.

Implantable electrical bone stimulation for arthrodeses of the foot and ankle in high-risk patients: a multicenter study

This study assessed arthrodesis procedures performed in the foot and ankle of high-risk patients following implantation of an internal electrical bone stimulator. Criteria defining patients as "high risk" included diabetes, obesity, habitual tobacco and/or alcohol use, immunosuppressive therapy, and previous history of nonunion. Standard arthrodesis protocol of bone graft and internal fixation was supplemented with the implantable electrical bone stimulator. A retrospective, multicenter review was conducted of 26 patients (28 cases) who underwent 28 forefoot and hindfoot arthrodeses from 1998 to 2002. Complete fusion was defined as bony trabeculation across the joint, lack of motion across the joint, maintenance of hardware/fixation, and absence of radiographic signs of nonunion or pseudoarthrosis. Radiographic consolidation was achieved in 24 of the 28 cases at an average 10.3+/-4.0 weeks. Followup averaged 27.2 months. Complications included 2 patients who sustained breakage of the cables to the bone stimulator. Five patients underwent additional surgery. Four of the 5 patients had additional surgery in order to achieve arthrodesis. All 4 went on to subsequent arthrodesis. This study demonstrates how arthrodesis of the foot and ankle may be enhanced by the use of implantable electrical bone stimulation.