Innovations in Foot and Ankle Pain Treatment: Advances in Medical Technology

The foot and ankle are made up of 26 bones, 33 joints, and more than 100 muscles, tendons, and ligaments. These move the foot to adapt to different surfaces and absorb shock in the process. The great range of possible movement and the need for precise stability in activities such as sprinting and jumping is achieved by the anatomy of the foot and the coordinated actions of its components. All of these make the foot at particular risk for injury, often more so in athletes than in the general population. Whether an athlete or not, anyone can experience foot and ankle pain and/or injury, often incurring a resultant physical impairment and functional limitation. According to a recent study of community-dwelling women, 20% reported foot pain on over 5 days in the past month. Contributions to the high incidence of foot and ankle pain are the effects of increasing age and prolonged weight-bearing activities on the lower extremities. As life expectancy increases, there will likely be a growing number of older individuals with chronic foot and ankle conditions. Recognizing the disabling effects of foot and ankle pain, there has been a surge in the development of more effective methods to assess and treat the wide variety of lower extremity disorders. Peppin believes that innovations in foot and ankle pain treatment must be driven by the expression of patient-oriented outcomes. As improvements in medical technology occur only insofar as they are considered necessary, feasible, and most beneficial to the patient, an understanding of individual patient needs is paramount in dictating the trends of progress in foot and ankle medicine. One such prerequisite to an improved understanding of foot and ankle pain conditions is the development of reliable diagnostic tools. The current methods of assessing the painful foot or ankle are often limited to a physical examination and plain films. However, many latent conditions can escape clinical detection, and normal radiographs do not rule out a stress fracture or degenerative arthritis. One study showed that the history and physical examination alone are insufficient to rule out an acute fracture in the Ottawa ankle rules group. Misdiagnosing a fracture can lead to detrimental consequences, such as prolonged immobilization of a sprained ankle which may cause a delay of rehabilitation and predispose an individual to chronic pain or recurrent injury. MRI is often used to rule out a fracture or detect soft tissue injuries, but the high cost has led to an apprehensive acceptance of using it as a first-line diagnostic tool. Ultrasonography is an alternative method with comparable sensitivity and specificity to MRI in detecting soft tissue injuries. Its non-invasive approach and cost-effectiveness make it a viable option for office-based imaging. Continued improvements in ultrasonographic technology can further enhance its capabilities and thus increase its utilization in the field of podiatric medicine.

Overview of Foot and Ankle Pain

The issues of chronic pain on lifestyle and the economic burden on the healthcare system have been the driving force in trying to understand mechanisms behind the pain and how best to treat the cause effectively. This is still a relatively under-researched area, especially when compared to the knowledge of knee and hip arthritis. Pain has been shown to have a wide variety of causes, including degenerative diseases (osteoarthritis, rheumatoid arthritis), acute ligament injuries, and post-trauma pain and deformity. Pain is often localized but can be referred from solid organ or neural causes.

Foot and ankle pain may be a deformation, a swollen part, an ingrown nail, or any soft-tissue injury. It is reported that up to 40% of the people in developed countries suffer daily pain in the foot and ankle. The pain and discomfort can make simple daily activities, like getting to the shops, work, and getting around the house, very difficult. But over the past ten years, what has become more apparent is the involvement of foot and ankle pain in the ever-increasing sedentary lifestyles that people are taking on. This issue comes at an ever-increasing financial burden on the healthcare system, not just in the cost of treatment but in the amount of days off work.

Importance of Effective Treatment

An example of an outdated and generally ineffective treatment for a certain type of foot pain would be the use of Custom Foot Orthotics for treatment of plantar fasciitis. More information may be found in the evidence-based article.

Finally, foot problems were deemed to be a major cause of falls in older people. Inability to identify an effective treatment for chronic foot and ankle pain has left many people needlessly suffering for years on end. This article touches on a variety of new technologies and techniques that have proven to be quite successful in the treatment of foot and ankle pain. All of the procedures mentioned are evidence based, meaning that they have been tested and shown to be consistently effective. Older treatments and techniques that have been known to end in mixed results will not be discussed.

In one study of persons over 65 years, those with severe foot pain were more likely to have a lower overall score on the SF-36, a measure of health status, than those suffering from chronic medical conditions such as congestive heart failure, heart attack, or diabetes. Older people with foot pain reported limitations in their ability to perform activities of daily living (ADL) such as bathing, dressing, and walking. In some cases, severe pain and problems in the lower extremity result in the limitation of higher level activities (e.g. mobility inside and outside the home) which leads to a loss of independence.

The importance of effective treatment for foot and ankle pain cannot be understated. In the last decade, a number of publications have addressed the impact of foot problems on the health and well-being of older people. Evidence indicates that foot problems diminish quality of life and impede the ability to live independently.

Non-Invasive Treatment Options

Physical therapies are used to prevent and correct injuries related to sport or recreational activity. They are usually considered the first line of defence in treating acute ankle sprains and chronic ankle instabilities. The focus of therapy is to increase the strength of the lateral muscles on the affected ankle. This can be achieved by resistance exercises using weights, therabands, and body weight. Proprioception is the body’s conscious awareness of where a joint is in space and time. Studies have shown that people who have suffered ankle sprains have hindered proprioception compared to those with healthy stable ankles. An improvement in proprioception can help prevent chronic ankle instabilities. This is usually achieved through a variety of balance and coordination exercises. In addition to resistance and proprioception exercises, therapists can use manual therapy techniques on ankle sprains to decrease pain and return the patient back to participation. This may involve joint mobilizations, massage, and electrotherapy modalities. The forms of manual therapy will depend on the phase of healing and the patient’s goals. Any therapist intervention for an ankle sprain should be supported by a functional progression to ensure a return to previous activities at a similar level or higher. This can be assessed using functional assessments like the SEBT and the patient’s self-reported function. The use of targeted therapies has been shown to constitute a viable treatment option for ankle fractures at various stages of recovery. Ankle fractures are particularly common among the elderly and post-menopausal women, often necessitated by weaker bones and fragile ligaments. These fractures occur from minor trauma and are indicative of more serious bone disease. The mortality for post-menopausal women after sustaining a hip fracture is relatively high and is indicative of a need to prevent these luxations further down the kinetic chain. By using a targeted conservative treatment for elderly patients, doctors can reduce complications and allow for a faster general recovery.

Physical Therapy and Rehabilitation

Physical therapy is the primary line of defense for patients suffering from foot and ankle ailments and is the most widely used non-invasive treatment option. There are many different methods that can be utilized, and treatment should be individualized based on the specific pathology. Therapy can be passive, where the patient is treated with modalities such as ice, ultrasound, and electrical stimulation, or active, which incorporates therapeutic exercise to improve strength, flexibility, and function. Range of motion exercises focus on joint mobility and flexibility and typically come before strengthening exercises. Patients can use simple home exercises or can be treated in a formal therapy setting depending on the severity of their condition. Gait or walking pattern abnormalities can be corrected with the use of gait training, and patient education is stressed in order to help prevent future recurrences of foot and ankle pain. Rehabilitation from foot and ankle injuries is a slow process. Patients are often unable to bear weight or walk regularly for months following an injury or surgery, and they may experience atrophy or muscle weakness due to lack of use. It can take 4-6 months to return to full function following a sprain or fracture, and up to a year or more after procedures to the rear foot or ankle. Utilizing physical therapy or formal rehabilitation from a qualified therapist is essential in guiding patients through this process and assuring the best outcomes. A recent study on rehabilitation following ankle fracture for patients older than 60 showed that patients receiving rehabilitation had significantly better functional outcomes and less residual pain than those who did not. This suggests that even in older populations, it is worthwhile to take the extra time and effort to rehabilitate from foot and ankle injuries.

Orthotic Devices and Bracing

Ankle Foot Orthoses (AFO) are externally applied devices that encompass the foot and ankle joint and are designed to control the position and motion of the ankle, compensate for weakness, or unweight a certain area. They are widely used for numerous conditions across all age groups. Traditional custom AFOs were made from a plaster mold and could be quite bulky and uncomfortable. Developments in technology have led to devices being more commonly made from thermo-plastic materials. These are heated and molded to the patient for a better fit and can be readjusted or remolded if necessary. Computer-aided design (CAD) and manufacturing (CAM) technologies have also led to the development of more streamlined custom AFOs, which are lighter and more cosmetically acceptable. Traditional custom AFOs are still often prescribed given the cost of modern devices can be prohibitive, and there is no strong evidence that they provide better clinical outcomes for many conditions.

The use of orthotic devices is based on the premise that it is possible to alter or modify the neuromuscular and skeletal function of the lower limb in order to alleviate symptoms and prevent the progression of foot and ankle deformities. One of the key challenges of prescribing foot orthoses is matching the device to the pathology. This can be difficult given that a single foot pathology often results in a variety of symptoms and deformities. Patient compliance is also essential for successful treatment, and compliance is often related to the comfort of the orthotic device. The requirement for comfort and the sheer complexity of foot deformities have led to the development of more customized orthotic devices that utilize evolving technology.

Orthotic devices are widely used in the treatment of various foot and ankle pathologies to both correct malalignments and alleviate symptoms. They range from simple foam or felt insoles made custom to the patient’s foot to rigid plastic insoles or boots that are designed to restrict abnormal motion of a joint. The evidence for foot orthoses is mixed, with some foot pathologies such as rheumatoid arthritis having evidence that orthoses provide clinical benefit, while in other conditions such as metatarsalgia, there is no evidence.

Extracorporeal Shockwave Therapy

Extracorporeal shockwave therapy (ESWT) is one of the most recently widely recognized treatments for plantar fasciitis. The technique utilizes focused shock waves to stimulate a healing response in chronic plantar fasciitis. ESWT has been shown to be effective for patients who have failed conventional, conservative treatment and are considering surgical options. A 2004 study demonstrated that ESWT can provide an 80% success rate at 3 months. A recent meta-analysis of 9 studies that incorporated 3,007 patients and follow-up ranging from 3 to 12 months indicated that ESWT demonstrated a superior outcome when compared to traditional conservative management. ESWT has low morbidity in comparison to surgical intervention; however, the treatment is not without potential complications and a period of post-treatment impairment. High-energy shockwave therapy may be painful and often requires either a regional or general anesthetic during the procedure. There have been reported cases of hematoma, petechiae, skin reddening, and rupture of the plantar fascia. A recent paper reported on the safety and efficacy of low-energy shockwave therapy for the treatment of chronic plantar fasciitis and concluded that it was safe with a low rate of minor complications and provided clinical benefit over 3 months of follow-up. Despite the potential complications and the need for impairment in the days following treatment, ESWT is a viable alternative to surgery for recalcitrant plantar heel pain and helps to reduce further burden on the patient and healthcare system in an economic climate that has a desire to move away from the current high rates of surgical intervention seen for various musculoskeletal conditions.

Minimally Invasive Procedures

Arthroscopy is a surgical procedure in which a small fiberoptic camera (arthroscope) is inserted into a joint to allow visualization and treatment of internal joint problems. It has the advantage of being minimally invasive in that it requires only small incisions about the joint and can be performed in a day surgery setting. Techniques are constantly being developed in foot and ankle arthroscopy and can involve anything from simple removal of some offending tissue to more complex realignment of a joint through cutting and repositioning bones. Common procedures include debridement of arthritic joint, microfracture of osteochondral lesions, and repair of ligament tears. A recent systematic review identified high-quality evidence supporting arthroscopy in the treatment of ankle arthritis and osteochondral lesions of the talus with the authors noting particularly good to excellent patient outcomes in the latter 80% of the patients. A list of arthroscopic procedures and the evidence supporting them is beyond the scope of this article, but the upshot is that modern arthroscopy provides a useful tool in the treatment of a range of foot and ankle pathologies.

A fundamental shift in the treatment of foot and ankle pain has been the development of minimally invasive procedures which seek to aggressively treat pathologies while minimizing soft tissue damage and scar tissue formation. This is a significant departure from traditional surgical techniques that often required long incisions and extensive dissection in an effort to gain wide visualization of the area and often led to an overly aggressive approach to the identified pathology. This theme of “minimal intervention for maximal benefit” is a common philosophy amongst the techniques covered in these procedures.

Arthroscopy for Foot and Ankle Pain

On physical examination, the patient was noted to have anterior ankle swelling and tenderness to palpation over the anterior ankle. Range of motion of the ankle was decreased compared to the left ankle, particularly limited in dorsiflexion. The patient had a positive anterior impingement sign with reproduction of his pain on forced plantar flexion and dorsiflexion of the ankle. Ankle stability was intact. An MRI was obtained which showed degenerative changes in the anterior ankle consistent with osteoarthritis and synovitis. Given the patient’s young age and desire to maintain an active lifestyle, OLT was considered as a treatment option for the osteoarthritis.

Platelet-Rich Plasma (PRP) Injections

Platelet-rich plasma (PRP) has emerged as a treatment alternative for patients with tendon injuries. A review of basic science studies outlining the role of PRP in tendon healing is presented. These studies suggest that PRP is potentially effective in the early phases of the healing process. The efficacy of PRP in the treatment of chronic tendon injuries is to be determined by large-scale clinical trials that include validated clinical outcome measures and standardized preparation of PRP. A clear definition of the composition of an effective PRP preparation and a thorough understanding of the mechanism of action of PRP on tendon healing are required to determine the most effective application of this treatment modality. Simulation using these new technologies is a start. Level of evidence: Level V, expert opinion.

Stem Cell Therapy

Randomized clinical trials are required to further investigate these applications of stem cell therapy to arthritis and joint preservation, but the early results suggest a potentially disease-modifying intervention that could avoid the need for joint surgery.

An early clinical trial treating osteoarthritis of the knee with intra-articular injection of autologous MSCs has shown promising results in terms of reduced pain and an improvement of function at the six-month period post-injection. A pilot study into the treatment of avascular necrosis of the femoral head with injection of stem cells cultured from the patient’s bone marrow has also shown encouraging outcomes.

The concept of using mesenchymal stem cells (MSCs) in an arthritic joint is to reduce inflammation and pain and to regenerate hyaline cartilage that can integrate with the surrounding normal cartilage. This would prevent progression to debilitating end-stage arthritis, and the joint could be preserved in a more normal and functional state.

In the field of arthritis treatment, current surgical management in the form of joint fusion or replacement is effective in terms of pain relief and restoration of function. However, joint function is still markedly abnormal and the health status following surgery over the long term has been shown to be only marginally better than that of the average patient who is not a candidate for such surgery. Joint replacement also has a limited lifespan and is not suitable for younger patients.

The potential scope and role of stem cell therapy in tissue healing and regeneration is an exciting area. Basic science and clinical research have been initiated to investigate the applications of stem cell therapy to various orthopedic conditions with the hope of developing a regenerative treatment that will avoid the problems and morbidity associated with current surgical techniques.

Radiofrequency Ablation

Radiofrequency ablation is a minimally invasive procedure that is performed in the office. It has been in use for over 30 years with the primary focus on pain management. It is safe and highly effective. A small cannula is placed into the foot that has a bendable tip for access to all areas of the foot. The cannula is the diameter of a toothpick, so it is easily tolerated. The doctor will then insert the radiofrequency probe through the cannula and numb the area for treatment. The part of the probe that will be inside the body is bent to create a small loop that will treat a 5mm area of tissue. This probe will then be inserted into the area with the guidance of fluoroscopy to ensure that the area is treated effectively. The radiofrequency waves will heat the tissue and create a thermal lesion. This lesion will disrupt the nerve function in the targeted area. A recent study has shown an 85% success rate six months post ablation. Great results have also been shown in the treatment of neuromas and arthritis-related pain. This technique is covered by most insurance companies and provides long-term relief for chronic pain. A protective walking boot will be worn for 2 weeks with a very minimal recovery time.

Surgical Interventions

Nerve decompression surgery is a treatment for a pinched (compressed) nerve. Tarsal Tunnel Syndrome is a condition where posterior tibial nerve is compressed as it travels through the tarsal tunnel on the inner side of the ankle. Published evidence on the effectiveness of tarsal tunnel release is sparse, however it is generally considered that the better the preoperative diagnosis, the better the results of surgery.

Tendon repair and reconstruction is a treatment for patients who have continuing pain, weakness, instability and poor movement due to tendon damage. There are many different types of tendon repair and reconstruction surgery and each is specific to the involved tendon and the nature of the problem. Commonly a damaged tendon will eventually lead to a change in the position of the affected joint and this often leads to a deformity. In these instances it is the change in joint position that the surgeon aims to correct and the tendon repair is simply a means to this end. Successful tendon repair or reconstruction can have a profound effect in restoring pain free, functional movement.

Fusion procedures involve removing the damaged cartilage and bone so that the two affected joint surfaces are then fused. Fusion can be performed using different techniques involving screws, plates and bone graft and it is the gold standard surgery for arthritis in the big toe. Fusion procedures are usually of benefit to patients who have a heavy manual occupation, or those who wish to maintain a high level of exercise and sports.

Joint replacement involves removing the damaged joint and replacing it with an artificial joint. Joint replacement is performed under a general anaesthetic. The results of joint replacement are varied depending on the joint involved. Due to the success of hip and knee replacements, an increasing number of younger patients are now considered for joint replacement surgery. The cheapest and most common time for joint replacement of the ankle is in the older (65+) inactive patient. Early results for total ankle replacement have been promising and it is likely that the numbers of replacements done will continue to increase.

There are numerous surgical interventions that are now available to those who suffer from chronic foot and ankle pain. The choice of surgery is based on the severity of the pain, the changes that have already occurred to the affected joint, and the patient’s past response to non-surgical treatment.

Joint Replacement Surgery

As with all surgeries, there are potential complications with joint replacement surgery of the ankle, including those associated with the use of anesthesia, and the risks of infection and nerve damage. Although the risk of complications occurring is relatively low compared to potential benefits, it is useful for patients to ask their surgeon about the possible complications that could occur.

Success rates are different between the ankle and other joints, due in part to the complexities and significant differences in bone shapes, densities, and joint motion in the ankle, as well as the higher general activity level of ankle arthritis patients. In cases of severe ankle arthritis or when the pain from arthritis is not relieved by non-surgical treatments, replacement of the ankle joint will often provide pain relief and improved motion.

Joint replacement surgery has become one of the most successful, as well as the most common, procedures to improve the quality of life for patients with arthritic conditions. Overall, success rates for joint replacement surgery of the ankle are not as high as for joint replacements in other areas such as the hip or knee. However, in cases of patients suffering from arthritis in the ankle, joint replacement surgery has been shown to produce great improvements in overall motion, pain relief, and the ability to perform daily activities.

Joint replacement surgery is used to remove the damaged parts of the foot and/or ankle and replace them with artificial joints. It is most commonly used to treat arthritis that affects the foot and ankle. In general, the procedure of joint replacement involves removing the damaged joint and soft tissue and then inserting an implant, which is usually composed of a metal base and a plastic cushion.

Arthrodesis (Fusion) Procedures

Ankle arthrodesis is the process of surgically removing the cartilage that lines the ankle joint and then fusing the joint to make it solid. Arthrodesis is generally indicated for patients with severe pain and moderate to severe secondary osteoarthritis, or in cases of severe deformity. The most common indication for arthrodesis is post-traumatic arthritis. Other indications include inflammatory arthritis such as rheumatoid arthritis and arthritis resulting from other systemic joint disorders. Arthrodesis has become the standard of care for the treatment of end-stage ankle arthritis. The procedure remains the treatment of choice to alleviate pain and provide lasting functional improvement. Ankle arthroplasty has also become a viable alternative to arthrodesis in older patients with lower demands for physical activity. Current generation two and three component designs have significantly improved clinical outcomes when compared with earlier generation implant designs. The advantage with arthroplasty is that the joint is not fused and therefore maintains range of motion in the ankle. Patients undergoing arthroplasty should also be aware that conversion to arthrodesis may be necessary in the future. Chronic joint pain due to implant subsidence, loosening, infection, or other complications may require conversion to arthrodesis. This is important to consider for younger patients and those with higher physical demands.

Tendon Repair and Reconstruction

Advancements in medical technology have allowed for the development of new methods in tendon repair. Tissue engineering produced using tendon stem cells has shown promise. A study concluded that a tissue-engineered tendon using a polyglycolic acid sheet can restore the morphology and preserve the structure of the natural insertion site of the Achilles tendon in a rabbit model. Further developments include the use of biologics, such as platelet rich plasma (PRP) and stem cell therapy. These are thought to augment the natural healing process, reduce scar tissue, and improve tendon function. Despite some promising results, further research is required to assess the efficacy of these methods in comparison to traditional repair techniques.

Tendons transmit force from the muscle to the bone, enabling movement. Damage or tears to tendons impair quality of movement and cause a loss of mobility in patients. There are many techniques that have been utilized over the years, from primary repair to advanced techniques that involve tendon transfer. Primary repair is most advantageous in healthy patients with acute tendon rupture. End-to-end approximation can be used, or suture anchors. Chronic ruptures or neglected cases in those with co-morbidities require advanced techniques with tendon transfer, which involve substantial postoperative rehabilitation.

Nerve Decompression Surgery

Nerve decompression procedures not only reduce the chronic pain states that the patient is suffering but also have a faster recovery rate and are generally less painful than pain management therapies, especially in the case of surgery with space-occupying lesions. Nerve decompression surgeries have a high success rate at reducing moderate to severe chronic pain states.

There are several forms of nerve decompression, which include neurolysis, perineural and epineural digestion, and transposition. Neurolysis is the freeing of adhesions and scar tissue, which may be trapping the nerve. Perineural and epineural digestion are aimed at breaking down inflammatory tissue around the nerve, which is a common cause of nerve entrapment. High-pressure circulated anesthetic has been used to perform a chemical neurolysis temporarily to release nerve entrapment. Nerve transposition is a form of nerve decompression where the nerve is relocated to an alternative site. This decompression process is followed by the repair and reconstruction of the destroyed pathway.

During the course of OSN entrapment, the nerve is compressed leading to severe pain and possible permanent nerve damage. The cause of tarsal tunnel and other compressions has been documented due to space-occupying lesions, acute or chronic inflammatory processes, and systemic diseases. The entrapment sites are characterized by the level at which the nerve is compressed and the type of tissue causing the damage.

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