Introduction

The insertional Achilles tendinopathy (IAT) presents with varied clinical manifestations. Calcific deposits with increase in rigidity of the tendon thus disturbing its normal interaction with the upper part of the posterior wall of the calcaneus (referred to as Haglund’s prominence). In a healthy subject this area has a glossy surface with a small bursa present thereby minimizing friction. Any pathology on either calcaneus (e.g. Haglund’s disease), within the tendon or surrounding soft tissue (inflammatory bursa), may trigger pain. Abnormality of the upper part of the posterior wall of the calcaneus can be assessed radiologically by measurements. Most commonly used is the Fowler-Philip angle [1]. However, inter-observer and intra-observer variability in measurement of the angle [2] makes it difficult to apply as a guide for surgical intervention. There are other published methods of calcaneal measurement [2]. It is unclear whether pain in IAT comes predominantly from the tendon, the bone or adjacent inflamed soft tissue [3]. Some authors therefore address all three components during surgical intervention [4], i.e. combined excision of posterior calcaneal prominence (regardless of Haglund’s deformity),closing wedge calcaneal osteotomy, excision of bursas and debridement of calcific deposits from the Achilles tendon. Other reports recommend an isolated excision of the surrounding bursas in selected cases [5].
The primary debridement of Achilles tendon insertion with bone suture reinforcement and excision of Haglund’s prominence (regardless of radiological measurements) aims to address the pathology directly (Fig. 1).
The rationale behind an isolated modified Zadek’s osteotomy in treatment of IAT is to minimise direct contact between Haglund’s prominence and degenerated tendon thus subsequently to reduce inflammation of adjacent soft tissue. In addition, the dorsal closing wedge osteotomy changes the foot–ankle leverage (Fig 2A). There is also a change in position of calcaneal tuber and the body of the calcaneus in relation to the ground surface. The calcaneal tuber migrates proximally and anteriorly, while calcaneal body drops slightly inferiorly (Fig. 2B). Subsequent change in orientation of force vector on Achilles tendon and its magnitude may play some role in pain relief.
The aim of this study was to analyse our experience with the two surgical methods mentioned above.

Materials and methods

35 patients (36 feet) who had failed conservative management were considered for surgery. The non-operative management included activity modifications, analgesics and non-steroidal anti-inflammatory medications, orthotics, footwear modification and physiotherapy. All patients had symptoms for at least 12 months prior to surgical intervention. We had 25 patients in the open debridement and 11 patients in the calcaneal osteotomy group. Demographic details include age, sex, side, co-morbidities, date of procedure, length of follow up, patient based MOXFQ questionnaires and surgeon’s follow up assessment were used to assess outcomes. Responses from patients were also recorded based on the more Achilles tendon specific VISA-A questionnaires.
Patients were evaluated by senior authors prior to listing for surgery and carefully assessed for tenderness, deformity, gait and Achilles integrity. All patients in this study had radiographs of the heel lateral view and confirmation of diagnosis either with an ultrasound scan and or magnetic resonance imaging (MRI). We also performed routine blood tests to aid other diagnosis of gout and inflammatory conditions.

Surgical techniques

The open debridement of Achilles insertion included a single surgeon cases from 2010 to 2019. Surgical technique involved posterolateral, posteromedial or direct posterior approach in prone position (Fig. 1). Debridement of the tendon included removal of calcific deposits, excision of Haglund’s prominence and reinforcement with suture anchors or fibre tape. None of the patients had another tendon used as augmentation. Post-operative regime included non-weight bearing in plaster cast for six weeks. Those subjects who had fibre tape reinforcement were allowed to partial weight bear in a protective boot after 3 weeks.
The osteotomy group treated exclusively by another senior author had modified Zadek’s osteotomy without any additional procedures (Fig. 2C). Surgical interventions were performed from 2014 to 2019. Modified Zadek’s technique was utilised. Apex of closing wedge osteotomy was distal to the origin of the plantar fascia on the calcaneus, i.e. to the front of the conversion point from the convex contour of the calcaneal tuber and concave contour of the calcaneal body cortex thus avoiding calcaneus attachment of calcaneo-fibular ligament (Fig. 2B). The plantar cortex was kept intact at the apex of the osteotomy. Fixation of osteotomy was achieved using various types of screw systems (Fig, 2C) or calcaneal compression plates. Postoperative regime was non-weight bearing in a plaster cast for 6 weeks.
DVT prophylaxis included either low molecular weight heparin or Rivaroxaban for minimum 6 weeks for both cohorts.

Results

A total of 36 feet (35 patients) were assessed with an overall mean age of 52.6 years. (Age range from 31 to 68 years in the debridement group and from 18 to 64 years in the osteotomy group). There were 17 males and 18 females. 20 were right-sided procedures. Mean follow-up in the outpatient clinic for a clinical examination was 20 weeks. We expanded our observation period to 8 years in the debridement group and 4 years in the osteotomy group with an up-to-date score based on VISA-A questionnaire and MOXFQ. The open debridement group showed 76% (19 patients) to have a good to excellent outcome. The calcaneal osteotomy group showed 82% (9 patients) to have a good to excellent outcome. Osteotomies were united in all patients.
There were no wound complications or incidence of thromboembolism in either group.
During the long term follow up, 2 patients in the debridement group had recurrence of calcification and symptoms requiring additional procedures. (One required a further debridement and the other had modified Zadek’s osteotomy). One patient in the osteotomy group developed plantar fasciitis 18 months after surgery.

Discussion

Insertional Achilles tendinopathy is a challenging condition. When it is combined with an enlargement of posterior calcaneus, it has been described as a Haglund’s syndrome [6]. Many patients improve with non-operative measures including physiotherapy, orthotics, activity modification and analgesics. However, failure of non-operative treatment may require surgical intervention. We did not perform surgery in any patients who had symptoms for less than a year.
There is no consensus in the medical literature as to the best way of surgical management of this condition. Reports of subcutaneous bursa having the highest degree of innervation when compared to the retrocalcaneal bursa, the Achilles tendon, and the calcaneal bone [3] led some authors to excision of subcutaneous bursa alone in selected patients [5]. Others recommend retrocalcaneal bursa excision [7], calcaneoplasty alone [8], open tendon debridement and reattachment [9], arthroscopic debridement [10] and closing wedge calcaneal osteotomies [4,11,12,13] and [14]. To our knowledge, there are very few studies comparing the various surgical modalities [15].
In our experience, both surgical methods (primary open debridement and osteotomy) are valuable in treating IAT. We had similar comparable short, medium and long-term outcomes between both groups. The improvement achieved in both groups was alike, though number of patient analysed was not large enough to have statistical analysis. Initial recovery time was also almost identical. Both groups had recommended 6 weeks of non-weight bearing in a below knee cast. The usage of fibre tape augmentation of the Achilles tendon repair has allowed little earlier rehabilitation. However, Maffuli et al. [4] noted longer period in return to sport following primary open debridement as compared to osteotomy patients in athletic population. In this study, patient groups involved were less active and none were professional athletes.
We did not have any problems with achieving bony union in calcaneal osteotomy group. We believe, that modification of original description of osteotomy by Zadek [11], by positioning the apex of the osteotomy more distal than the original description makes this procedure safe and reliable. We assume that localisation of the apex of osteotomy just distal to the origin of the plantar fascia on the calcaneus prevents any cephalad migration of the calcaneal tuber should metalwork fixation fail. We used various internal fixation methods to achieve compression at the osteotomy site. As the plantar cortex of the calcaneus was left intact, there was a substantial force needed to achieve good compression. We did not have any preference of one fixation method over the other in the osteotomy group except for recommending two standard screws. However, majority of our patients had a lag screw through a post system allowing for enhanced compression (Fig. 2C).
In the primary open debridement group, we did not undertake any tendon transfer [16]. Some authors have recommended tendon transfer if more than 75% tendon is affected. Calcaneoplasty alone (excision of posterior tubercle) has shown variable outcomes [6, 8]. Lee et al noted very good outcome in athletic group [8]. Whereas others noted disappointing outcomes [6]. We have combined the calcaneoplasty along with excision of calcific debris from within the substance and augmented the insertion with either suture anchors alone or more recently with a fibre tape augmentation (in surgical debridement group).
In surgical debridement group, we encountered radiological recurrence of calcifications with symptoms in 2 patients. As we routinely did not perform follow-up radiographs in this group, we cannot exclude that some patients may have developed asymptomatic calcific deposits again. We did not encounter any recurrence of symptoms in osteotomy group so far. However, we noticed in one patient progressing intra-tendinous calcification but without recurrence of symptoms (Fig. 2C). Literature reports several complications, including slow healing of osteotomy, reduction in push off, and loss of shape of the heel with difficulty in shoe wears.
The limitation to this study is that it a retrospective review with a small number of patients, thus without statistical significance. The results in this study are based on the VISA-A and MOXFQ scores. We did not analyse changes in the gait pattern following surgical interventions, as this was retrospective analysis. We did not have competitive athletes in our groups.
Conclusion

Both surgical methods of treating long standing insertional Achilles tendinopathy proved to be safe and reliable in short, medium and long term observation periods. There were no complications in either group. Both techniques proved to be safe and reliable. We recommend larger prospective randomised controlled studies to compare the outcomes with these techniques.

References

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