Management: Make use of multiple modalities
Conservative management options for ankle OA are limited, and high-quality evidence of efficacy is lacking. Surgical alternatives, however, are invasive and yield modest outcomes. Therefore, unless specific indications for surgery are present, exhaust conservative options (TABLE 2) before considering referral.
Weight loss is important for those who are overweight—as with knee OA management—to decrease the reactive forces within the ankle joint and to decrease pain. Weight loss will also enhance the outcomes of other treatment modalities and improve overall health.10,11
Activity modification is usually required, even though this may make weight loss more difficult. Avoiding vigorous activities, restricting work-related movements that place high-impact stress on the ankle, and decreasing overall walking time often reduce the severity of symptoms and improve functioning in other activities. Use of assistive-devices, such as a cane, can decrease the weight-bearing load on the affected joint.10,11
Physical therapy has not been shown to alleviate pain in ankle arthritis, although stretching, joint mobilization, and gait training may help prevent further progression of arthritis and improve function.11 The strength of dorsiflexion and plantar-flexion muscles is often decreased in individuals with ankle arthritis. Strengthening exercises may be indicated in individuals exhibiting deficits.
Prescriptive conservative management. Begin with a combination, as needed, of anti-inflammatory medications, orthotic devices, and footwear modifications.
Nonsteroidal anti-inflammatory agents are generally safe, but long-term use requires monitoring. Intra-articular steroid injections have some supporting evidence of effectiveness, but any benefit is short-lived.12 Glucosamine and chondroitin, although unlikely to cause harm, are not supported by the evidence for use in ankle arthritis. Intra-articular viscosupplementation is controversial, and evidence is limited regarding its efficacy.13-15 And currently, insurance will not cover viscosupplementaton for any joint other than the knee.
Adding a rocker-bottom sole and a solid ankle cushion heel to a shoe helps decrease heel strike impact in individuals with decreased ankle motion, and they aid in the transition from the heel strike to the push-off during level walking.11 If the arthritic joint is unstable, a lace-up ankle support may help with proprioception and stability. A polypropylene ankle-foot orthosis, custom leather ankle corset, or a double-upright brace with a patellar-tendon-bearing support are options to restrict ankle motion and decrease weight-bearing forces.10,11
Immobilization is not recommended except for short-term use during an arthritic flare. Limiting ankle motion reduces pain, but the downside tradeoff is acquired stiffness and weakness that accompanies prolonged periods of immobilization. A controlled ankle motion walking boot or walking plaster cast are both reasonable options for the short term.
Consider surgical referral for specific indications such as osteophytes, loose bodies, and chondral defects, which may be treated with arthroscopy. Patients with large areas of exposed chondral bone or rapid onset of degeneration have poorer outcomes with conservative management and should also be referred to a surgeon earlier. Otherwise, consider surgical referral only after a full trial of conservative management.11
Surgical options vary in scope and effectiveness and include osteotomy, arthrodesis, and arthroplasty. Osteotomies can be performed in early OA to correct bony alignment deformities. Arthrodesis in neutral dorsiflexion with roughly 5 degrees of external rotation is reserved for end-stage ankle OA to allow for near normal gait and pain relief. Total ankle arthroplasty is an emerging option for severe ankle OA, resulting in improved pain relief, gait, and patient satisfaction, but potentially has a higher reoperation rate when compared with arthrodesis.1,2
CASE › We prescribed short-term immobilization with a controlled ankle motion boot and administered an intra-articular corticosteroid injection. At the patient’s follow-up visit 6 weeks later, he reported only moderate improvement in pain. We then advised physical therapy at a specialty ankle rehabilitation program to focus on mobilization, strengthening, and gait training. Nearly one year after his initial visit to our clinic, he is doing well. He understands, however, that the nature of his ankle arthrosis may necessitate surgical intervention in the future.
CORRESPONDENCE
Adam Bitterman, DO, Department of Orthopedic Surgery, Hofstra Northwell School of Medicine at Huntington Hospital, 155 East Main Street, Huntington, NY 11743; abitterman@northwell.edu.