Degenerative Conditions and Osteonecrosis of the Foot and Ankle

Degenerative Conditions and Osteonecrosis of the Foot and Ankle

Jensen K. Henry, MD

Constantine A. Demetracopoulos, MD, FAAOS

Dr. Demetracopoulos or an immediate family member has received royalties from Exactech, Inc.; is a member of a speakers’ bureau or has made paid presentations on behalf of Exactech, Inc.; and serves as a paid consultant to or is an employee of Exactech, Inc., In2Bones, MedShape, and RTI Surgical. Neither Dr. Henry nor any immediate family member has received anything of value from or has stock or stock options held in a commercial company or institution related directly or indirectly to the subject of this chapter.


Pain in the foot and ankle is incredibly common, affecting 1 in 5 adults older than 45 years.1 Degenerative conditions represent a substantial portion of these complaints, and can be a significant cause of pain, disability, and loss of function. Conversely, osteonecrosis of the foot and ankle is relatively less common, but prompt recognition and initiation of treatment will not only provide symptomatic improvement by lessening pain, but also prevent progression that can lead to arthritis and deformity. It is important to highlight the most common degenerative and osteonecrotic pathologies of the foot and ankle, with attention directed to initial nonsurgical treatments, orthotic/shoe wear recommendations, and surgical treatment strategies.

Ankle Arthritis

Ankle arthritis is a common painful and disabling condition of the ankle, affecting appropriately 6% of the population.2 Unlike the other major joints of the body, where primary osteoarthritis is the most common etiology, ankle arthritis is most commonly due to posttraumatic causes. More than 70% of patients with ankle arthritis report a history of trauma (fracture or chronic instability); less common causes include primary osteoarthritis, osteonecrosis, inflammatory arthritis, crystalline arthropathy, infection, neuroarthropathy, hemophilia, and hemochromatosis.3,4,5

In these patients, posttraumatic arthritis may result from the initial cartilage damage at the time of injury, or from residual malalignment of the ankle that leads to often rapidly progressive wear of the joint.3,5 Patients with ankle arthritis can experience debilitating pain and loss of function. Studies of patient-reported outcomes have shown that patients with ankle arthritis have Short Form-36 Physical Component Summary scores that are almost two standard deviations below the mean of the normal US population.6 Moreover, physical function scores in these patients are either similar to or worse than those of individuals with chronic kidney disease on dialysis, congestive heart failure, and Parkinson disease.6 Mechanical activity-related pain is a hallmark of ankle arthritis. Swelling and decreased range of motion are also common. However, patients classically lose key elements of function as well: patients with end-stage arthritis have significantly shorter step length, decreased peak ankle
flexion moment, decreased ankle power, slower walking speed, and decreased ambulation tolerance.3

All patients should undergo a thorough history and physical examination, including attention to prior injuries, extent of symptoms, and assessment of motion and alignment, as well as a neurovascular examination. Imaging work-up typically includes weight-bearing radiographs of the ankle, but may also include specialized views such as the hindfoot alignment view to assess for hindfoot malalignment. The traditional radiographic findings of osteoarthritis (joint space narrowing, subchondral sclerosis, osteophytic changes, and subchondral cysts) should be noted, but attention should also be paid to the alignment of the tibiotalar joint and lower extremity, coronal and sagittal plane deformities at the ankle joint, and alignment of the foot. Advanced imaging with CT and MRI is not required for diagnosis but can be utilized according to the surgeon’s discretion. CT of the ankle may be used to determine the bone quality of the ankle and assess for the presence of subchondral cysts. MRI may be used to assess for concomitant ligamentous insufficiency and degenerative tendinopathies, as well as avascular changes within the talus or distal tibial plafond. If the patient ultimately elects to undergo surgical intervention, weight-bearing CT may be useful to assess the three-dimensional standing alignment and bone quality, whereas MRI may identify focal cartilage defects.

Nonsurgical treatment modalities can be beneficial for symptom management in ankle arthritis patients. Like all arthritic conditions, activity modification, NSAIDs, and weight management can be useful.4,5 Shoe wear modifications, such as a supportive sneaker with a heel-to-toe rocker-bottom sole, may be beneficial.7 A more aggressive orthotic option is an ankle-foot orthosis, which provides excellent support with the caveat that it may be cumbersome or irritating with daily use.4,5 Corticosteroid injections may be both diagnostic and therapeutic in these patients, but should be used selectively, as the soft tissues of the foot and ankle are vulnerable to attenuation and destruction with multiple steroid injections.5

Surgical treatment of ankle arthritis continues to evolve. Multiple joint-preserving options have emerged, although their effects are still debated in the literature. Nevertheless, options such as ankle débridement with anterior tibial/dorsal talar exostectomy, supramalleolar tibial osteotomy, and ankle distraction arthroplasty with an external frame and tensioned wires have been pursued.4,5 Further study of the benefits of these surgical strategies, and the ultimate effects on their ability to delay or prevent joint-sacrificing surgery, is warranted.

For decades, ankle arthrodesis was the most accepted surgical option for tibiotalar arthritis. Fusion of the tibiotalar joint results in reliable pain relief, good patient satisfaction, and improvements in overall function.8 Arthrodesis can be performed with a variety of techniques and approaches, including open or arthroscopic, and can be stabilized with screws, plates, external fixation, or a combination of the above.4 Moreover, it allows for correction of severe malalignment and multiplanar deformities. However, ankle arthrodesis is not without complications and long-term concerns, and there are several valid criticisms. Complication rates are high, ranging from 9% to as high as 40% in some studies, and nonunion continues to be a major concern despite advances in surgical technique, fixation strategy, and the use of biologic adjuvants.9 In addition, ankle arthrodesis places aberrant stress on the adjacent joints and can accelerate arthritic changes in the hindfoot and midfoot joints.9,10

Total ankle arthroplasty has dramatically improved over the past 2 decades. Advancements in implant design and surgical technique have led to expanded indications and patient candidacy. Implant survival rates now reach 80% to 90% or higher at 5 to 10 years,9,11 and newer implants that were introduced to the market in the late 2010s have shown promising early results12,13,14,15 (Figure 1). Furthermore, in direct head-to-head studies of ankle arthrodesis and total ankle arthroplasty, total ankle arthroplasty more closely restores gait mechanics to normal, and has improved patient-reported outcome scores, foot mobility, and ability to navigate stairs and inclines.9,16

Hindfoot Arthritis (Subtalar, Talonavicular, and Calcaneocuboid)

The hindfoot includes the subtalar, talonavicular, and calcaneocuboid joints, which function as a complex to provide stability and shock-absorption throughout gait.5 Accordingly, when these joints are arthritic, patients routinely complain of pain with ambulation, and particularly when walking on uneven ground. Pain is usually localized to the specific areas of the affected joints; for example, patients with subtalar arthritis will have pain with palpation at the sinus tarsi. Arthritis in the hindfoot often results from trauma, such as a history of talar fracture (especially talar neck).5 Similarly, calcaneocuboid arthritis often develops after calcaneal fractures with extension through the anterior process of the calcaneus.5 Isolated talonavicular joint is less common, and often results from inflammatory disease, but also may be due to trauma, degeneration, or deformity.5

Nonsurgical treatment measures include NSAIDs, activity modification, bracing, orthotics, and injections. The mainstay of surgical treatment for persistently
symptomatic hindfoot arthritis is arthrodesis of the affected joint(s), via a single, double, or triple arthrodesis.

At the subtalar joint, arthrodesis has a good to excellent success rate, with union rates reaching 90% or higher5,17,18 (Figure 2). Outcomes are notably worse with a history of tobacco use, revision arthrodesis, or trauma with loss of calcaneal height.5,17,18 Although the rate of calcaneocuboid joint arthritis after trauma is high, it is often well tolerated by patients. Given the importance of maintaining motion within the lateral column of the foot, particularly for walking on uneven ground, many surgeons use a higher threshold to perform an arthrodesis of the calcaneocuboid joint.5,17 Arthrodesis at the talonavicular joint is more challenging. The unique spherical shape of the joint, as well as the challenges in exposing the entire joint surface, make arthrodesis at this region highly susceptible to nonunion.5,19 Moreover, fusion of the talonavicular joint has a tremendously limiting effect on the motion of the adjacent joints of the hindfoot, reducing motion at the subtalar joint to less than 10% of its native motion and leading to arthritic changes in one-third of patients.5,19

Midfoot Arthritis

Arthritis of the midfoot, which consists of the tarsometatarsal joints and naviculocuneiform joints, is a common but challenging problem. Similar to other areas of the foot, arthritis in this region is most commonly due to posttraumatic etiology, but may also be
due to primary osteoarthritis, inflammatory arthritis, or gout.20 Although the range of motion of the midfoot is relatively minimal (4° to 7°) at baseline, degenerative changes and further loss of motion have disabling and painful effects for patients.20,21 Patients will present with pain in the midfoot with ambulation that is exacerbated by activities that require rising off their heels.20 They often have dorsal bossing with painful osteophytes over the foot that preclude many types of shoe wear.5,20 In severe cases, patients go on to experience not just arthritic changes but deformity in the region, leading to abduction and dorsiflexion at the midfoot, a rocker-bottom foot, and pes planus.5,21

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May 1, 2023 | Posted by in ORTHOPEDIC | Comments Off on Degenerative Conditions and Osteonecrosis of the Foot and Ankle

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