Patients who have persistent pain and disability after adequate non-surgical treatment may be offered surgical debridement of the tendon. We would not normally offer surgery only for persistent swelling of the tendon as this is not usually a problem in itself.
A good review of surgery for Achilles tendinopathy is offered by Roche (2013) and a systematic review of treatment for insertional tendinopathy by Wiegerinck (2013).
Most surgical series describe a mixture of methods for midportion tendonopathy, including
- Release or excision of paratenon
- Release of adhesions
- Excision of grossly abnormal tendon, including, recently, plantaris
- Incision of lesser areas of tendonopathy to induce a healing response (although there is no clear evidence that this actually takes place).
- Reconstruction of defects
Many series contain mixtures of techniques and of patients with insertional and midportion tendonopathy as well as paratendonopathy. The extent of debridement varies from paper to paper. Some excise most abnormal tissue; others simply remove the worst sections, or only remove thickened paratenon, leaving tendon abnormalities alone.
Outcome measures are often imprecise, especially in older series, making it difficult to draw conclusions. The introduction of the VISA-A score, which is validated, has begun to improve this.
Minimally invasive and endoscopic surgery
Minimally-invasive techniques may aim to achieve at least some of the above aims.
Maffulli (2013) described a percutaneous, ultrasound guided technique of longitudinal tenotomy, under local anaesthetic. 30/39 patients reported good/excellent results using the Boyden scale at a mean of 17 years follow-up, and their mean VISA-A score was 78.5/100. 20 patients were still active in middle/long distance running. "Some" tenotomy wounds showed delayed healing, although with negative cultures.
Longo (2008) described a method of passing a thick suture percutaneously along the ventral and dorsal surfaces of the tendon inside the paratenon, intending to release adhesions and disrupt neovascularisation. 10/11 patients returned to their previous activities at 6 months. Long-term results have not been reported.
Alfredson (2011) described a technique of "scraping" the ventral surface of the tendon under local anaesthesia with a blade (106 tendons) or a needle (19 tendons), aiming to release the tendon from the ventral soft tissues. The mean visual analogue pain score decreased from 77/100 to 2 after a mean of 18 months follow-up. 37 tendons were in an RCT to compare mini-open blade release and percutaneous needle release; there was no difference in outcomes but no power study is presented. It appears 14/103 (13.6%) patients were dissatisfied with their result but the paper does not report whether they had further treatment.
Endoscopic surgery, using standard joint arthroscopes, allows adhesion release, paratenon release or excision, tendon incision and debridement. Vega (2008) reported 8 patients who all returned to sports by 3 months. Improvement was maintained after 3 years and nodules had all disappeared. While Vega debrided both dorsal and ventral aspects of the tendon, Thermann (2009) concentrated on the ventral aspect, aiming to disrupt the neovascularisations. He also reported 8 patients, this time with only 6 months follow-up. Mean VAS pain score was 97/100 and function score 90/100, and there were no complications of the procedure. Macquarrain (2013) reported 24 patients using the technique of Thermann, followed up for a mean of 7y. Mean VISA-A score improved from 37/100 to 98. There were two wound complications but no nerve injuries.
Pearce (2011) reported 11 patients in whom the ventral adhesions were released and the plantaris tendon divided. The mean follow-up was 2.5 years and the mean AOFAS hindfoot score improved from 68 to 92/100. Three patients got only partial pain relief but none required further treatment. A larger comparative trial would be needed to tell whether plantaris release adds anything to the results of simple debridement.
Two series reported plantaris release through small incisions. Alfredson (2011) used a 2cm incision to release and excise a portion of plantaris tendon at the point of maximum tenderness, along with scraping of the ventral Achilles tendon. The only outcome measure reported was that re-operation was required in six patients. van Sterkenberg (2011) reported three patients in whom a tendon stripper was used to excise the plantaris tendon throug a 4cm posteromedial incision in the proximal calf. There were technical difficulties in two cases but improvements were noted in VISA-A and pain scores. More rigorous studies are required to tell if intervention to plantaris adds anything to the minimally invasive surgery repertoire.
Open surgery
Probably the most informative series on traditional open surgery is that of Schepsis (1994). This included 73 procedures with very little loss to follow-up at a mean of 6.5 years. However, the pathology was mixed. Thickened paratenon was excised and abnormal tendon excised conservatively. Outcome measures were non-specific. Excellent or good results were obtained in 87% with peritendonitis and 67% with tendonopathy. Tendonopathy tended to recur 5-7 years after the original operation - it is important to tell patients this.
Vulpiani (2003) reported 76 patients at a mean of 13 years after surgery. Once again this was a heterogenous group, with 50/52 patients having little or no pain and back to the previous levels of sport after surgery for paratendonitis, non-insertional tendonopathy or mixed insertiona/non-insertional tendonopathy; only pure insertional tendonopathy did less well, with 26/34 achieving such results.
Nelen (1989) described 93 tendons with paratendonitis who had release of the paratenon and fascia, and 50 with tendonopathy who had resection of the abnormal tendon and simple suture (26 tendons) or flap reinforcement (24 tendons). Seventy-nine other patients were lost to follow-up, making it difficult to draw conclusions. Excellent or good results were obtained in 88% of paratendonitis and 80% of tendonopathy.
An extreme excisional technique is Martin's (2005) description of total excision of the diseased segment and FHL grafting. Three years post-operatively in 44 patients, SF-36 scores were US norms and mean AOFAS in a subgroup who were re-examined was 91.6/100, although the mean strength deficit was 30%.
Lengthening the musculotendinous unit
An alternative method was described by Costa (2006). 21 patients with non-insertional tendonopathy had open Achilles tendon lengthenings of 1cm, followed up for 1-16 years. No tendon resection was done. Post-operatively patients wore a BKW cast for 6 weeks. Results are not very clearly presented, but visual analogue pain score improved by a median of 20/100 for rest pain, 40/100 for walking pain and 50/100 for running pain (all significant). The Euroquol generic health score also improved significantly. The operated ankles had a mean of 5deg extra dorsiflexion, but this did not affect any measured gait parameters. There was one pulmonary embolus, three wound problems and one sural nerve injury. Possibly this result represents a rather extreme version of incision of the tendon to encourage regneration. However, it is interesting that Mahieu (2007) found that eccentric exercise also resulted in increased dorsiflexion - it might be that this changes the biomechanics of Achilles function in a beneficial way which is yet to be understood.
Two further studies have reported lengthening procedures. Kiewet (2013) lengthened the gastrocneimius tendon in 8 patients. The visual analogue pain score fell from 7.7/10 to 1 and the mean post-operative AOFAS hindfoot score was 94.4/100 (no pre-op scores were presented). Gurdezi (2013) reported release fo the medial head of the gastrocnemius in 9 patients with average follow-up of 2.5yr. Five patients with midportion tendinopathy had improvement of mean VISA-A score from 35/100 to 94, AOFAS hindfoot score from 62/100 to 91 and VAS pain score from 7.8/10 to 0.4, and all these differences were significant. Four patients with insertional tendonopathy had smaller, non-significant increases and all had further surgery.