Achilles Tendinopathy: What Are The Best Treatment Options?
While most will achieve adequate success without invasive treatment, recalcitrant cases will invariably present. Newer alternative therapies are continuously evolving with variable clinical success. A non-exhaustive list includes extracorporeal shockwave, pulsed electromagnetic field, low level laser and microtenotomy therapy.7-10 Currently, I use low-level shockwave therapy with variable success in this pathology. However, much of the research in this arena involves more of a subjective clinical pain response rather than pure scientific investigation.
If surgery is necessary, it is again imperative to rule out any other adjunctive pathology that may either coexist with tendinosis or may appear to be Achilles tendinopathy, and is clarified with further diagnostic investigation. I recall one patient who was referred to me for surgical consultation of a chronic case of “Achilles tendonitis.” As it turns out, the patient had profound pain with hyperplantarflexion of the ankle and we ultimately diagnosed the patient with a painful os trigonum. Excision of the accessory bone was curative.
At this point, or on occasion earlier in the workup, an MRI is indicated. This will serve to demonstrate the exact location of the degeneration. Obtaining a MRI also enables the surgeon to quantify the percentage of tendon diameter involved. While there is no scientific standard to apply, I will transfer the flexor hallucis longus (FHL) tendon if over 40 percent of the diameter is affected. The FHL tendon is the primary candidate for tendon transfer in cases of Achilles tendinopathy in so much that it is an “in-phase” transfer and is quite accessible anatomically.
When Should You Perform A Tendon Transfer?
The threshold of when to perform a tendon transfer is definitely a question of surgeon preference. Some contend that a transfer is essential in cases of Achilles tendinopathy while others have found success with debridement alone.
However, there is little debate that salvage tendinosis surgery should include a tendon transfer. There are various depictions of tendon transfer techniques in the literature.11,12 The technique I implement depends on the nature of the pathology. One of the primary considerations is how much tendon length is needed in the transfer. If the pathology focuses on the watershed area (zone 1), one can harvest the FHL tendon at the posteromedial ankle.
The author prefers a longitudinal, one-incision approach that curves anteriorly (following the natural course of the FHL tendon) distally. The ankle and the hallux are maximally plantarflexed as the tendon is transected as far distally as possible. Take care during this step as the neurovascular bundle will be in close proximity. The surgeon would then suture the FHL to the Achilles tendon, which has been debrided to excise all degenerated tissue. Preferably, surgeons would suture the tendon to the deep (anterior) aspect of the Achilles in a furrow which one can fashion with the aforementioned debridement.
Cases involving profound tendinosis and/or zone 2 pathology may require increased length of the FHL tendon graft. One can facilitate this with an additional incision at the sustentaculum talus or the proximal-medial arch. In one severe case, I transected the FHL tendon distal to the MTPJ. I subsequently pulled the tendon through an incision in the proximal arch and then finally through the posterior incision deep to the Achilles. This was necessary due to the profound nature of degeneration evident on the preoperative MRI.