Questions And Answers On The Pros And Cons Of Corticosteroid Injections
My previous blog, “Do You Inject The Plantar Fascia On The First Visit For Plantar Heel Pain?” prompted a higher than average number of reads and some interesting comments from my colleagues (see http://www.podiatrytoday.com/blogged/do-you-inject-plantar-fascia-first-... ). I want to add a few more insights and hope to get some more feedback on this controversial issue.
A third-year podiatric medical student posed an important question about the fact that plantar “fasciosis” is a degenerative condition and not an inflammatory process. Therefore, he questioned why we would ever use corticosteroids as a treatment tool.
I have heard other seasoned practitioners pose this same question. This underscores the lack of understanding about the histopathology of tendinosis or “fasciosis” as well as the role of corticosteroids to affect these processes. While there has been much study on the effects of corticosteroids on inflammation, there is not a lot of evidence about their effects on degenerative conditions of tendons or on the plantar fascia.
I referred the podiatric medical student to an excellent article written by six MD-PhD researchers from Finland.1 This paper explores the positive and negative effects of corticosteroid injections into connective tissue. It reveals evidence that corticosteroids inhibit the production of extracellular matrix, degrading enzymes that degrade the extracellular matrix of the tendon. There are reports that these enzymes are over-expressed in Achilles tendinopathy.2
However, there is also considerable evidence showing that corticosteroid injections can lead to significant loss of tensile strength of the tendon. How relevant these observations are to plantar “fasciosis” remains to be seen. As I discussed in last month’s blog, there is level 2 evidence that corticosteroid injections can significantly relieve pain and improve recovery in patients with plantar heel pain, and few other treatment interventions have shown this level of effectiveness.3 Clearly, if plantar heel pain is not an inflammatory condition, corticosteroids must have some positive effects in mitigating the histopathologic changes that predominate in plantar “fasciosis.”
What about the fear of causing an acute rupture of the plantar aponeurosis after injecting a corticosteroid? One respondent to my previous blog noted that he had seen three such cases of acute rupture among his own patients in whom he had administered a series of three corticosteroid injections. This colleague noted that none of the cases went on to long-term complications and all recovered uneventfully.
In my own observations of patients who suffered an acute rupture of the plantar aponeurosis, none developed long-term complications and all fully recovered with immobilization and appropriate physical therapy.
In one of the cases I saw last year, a middle-age male recovered from this injury and completed the Hawaii Ironman Triathlon competition nine months later. My assumption is that this gentleman, like most who suffer an acute rupture, did not actually tear the entire plantar aponeurosis but probably had a partial tear, which heals much better than any surgical plantar fasciotomy. This is why I am very reluctant to perform a plantar fasciotomy on any patient.
Finally, I have previously pointed out that patients can rupture their plantar fascia without ever receiving a corticosteroid injection. In fact, this presentation has been far more common in my own clinical experience than patients who have received an injection and subsequently ruptured the plantar fascia. I am not fearful of injecting the plantar fascia with corticosteroids.
However, I know these injections, by themselves, will not lead to a successful long-term recovery. Mechanical offloading of the plantar aponeurosis is the cornerstone of treatment for plantar heel pain. The podiatric physician, using biomechanical evaluation and functional foot orthotic therapy, has the most powerful tools to treat this epidemic condition.
(Editor’s note: For a related online poll, see http://www.podiatrytoday.com/node/2546/results .)
1. Paavola M, Kannus P, Jarvinen TA, Jarvinen TL, Jozsa L, Jarvinen M. Treatment of tendon disorders: Is there a role for corticosteroid injection? Foot Ankle Clin N Am. 2002; 7(3):501-513.
2. Magra M, Maffulli N. Molecular events in tendinopathy: a role for metalloproteases. Foot Ankle Clin N Am. 2005; 10(2):2267-277.
3. Crawford F, Thompson C. Interventions for treating plantar heel pain. Cochrane Database Syst Rev. 2000; (3):CD000416.