Zadek osteotomy for the treatment of Haglund’s Syndrome

Although several in paper, Haglund’s Syndrome extremity disorder. study the clinical outcomes of osteotomy (ZO) the Methods This retrospective study included 19 patients who underwent ZO from January 2016 to June 2018. Patients were evaluated using the American Orthopedic Foot Ankle Society ankle-hindfoot scale (AOFAS), Visual Analogue Scale (VAS), ankle range of motion (AROM), and Chauveaux-Liet (CL) angle preoperatively and at nal follow-up visit (16.3 ± 4.2) months. Postoperative complications of patients were also recorded.


Conclusions
ZO is effective and safe procedure for the treatment of HS. This method can be a good option for those patients of HS.

Background
In 1928, Patrick Haglund described the Haglund deformity rstly [1] . This deformity refers to an enlargement of the posterolateral heel, which can cause posterior heel pain. This symptom is referred to as Haglund's syndrome (HS), which includes insertional Achilles tendinopathy (IAT) [2,3] . The patient with HS often has a red, irritated, painful heel. And they often complain the enlargement of the posterior heel, which make it more di cult to footwear or sport. HS is a common disease. There are many conservative treatment options to treat it, which contains rest, activity modi cation, ice, or footwear modi cation [3] .
In 1939, Zadek described the ZO option for the treatment of HS rstly [7] . It was later modi ed by Keck and Kelly in 1965 [8] . ZO is a dorsal closing wedge calcaneal osteotomy that allows the tuberosity of Haglund deformity to be brought forward. This operation can change the calcaneus' anatomical length and elevate the distal insertion point of the AT [9] . The aim of this operation as the removal of the underlying bony prominence, which can reduce the impingement between the Achilles tendon (AT) and the posterior calcaneal tuberosity [10] . Keck and Kelly proved that ZO was an effective treatment for HS [8] . And Miller reported a good results in 16 patients of HS with that ZO option [11] . However, Myerson did not agree with osteotomy routinely because of increased morbidity compared with a posterosuperior prominence resection (PPR) [12] . But some patients still complain some degree of pain after PPR [13] . Therefore, another operation is required for better outcomes. However, few studies have reported the use of ZO to treat HS, especially in Asia.
This retrospective study aims to evaluate the effectiveness of the ZO for the treatment of HS.

Patients And Methods
Records of 25 patients with HS who underwent ZO from January 2016 to June 2018 at the Department of Foot and Ankle Surgery, Honghui Hospital, Xi'an Jiaotong University (Xi'an, China) were reviewed.
Informed consent was obtained from all study subjects. All procedures were performed by 1 foot and ankle orthopaedic surgeon. A minimum follow-up of 1 year after surgery was required for all patients.

Inclusion criteria were patients
Speci c inclusion and exclusion criteria were determined for selected patients. Inclusion criteria were patients over 18 years of age, at least 6 months of documented failed conservative treatment, and no prior foot and ankle surgery. Exclusion criteria were patients of HS with AT rupture, diabetes mellitus with or without neuropathic joint destruction, and local infection. Four patients were excluded according to the criteria, and another 2 patients were lost to follow-up. Therefore, 19 cases (19 feet) were included in the current study. The average age at the time of the operation was 48.6 ± 7.3 (range, 31-71) years. The mean follow-up time was 16.3 ± 4.2(range, 13-37) months. Data regarding age, gender, operative side, body mass index (BMI), smoking, and follow-up duration were collected.

Operative Technique
Patients was placed in the lateral position on the operating table. All patients received spinal or epidural anesthesia. A thigh tourniquet with 280 mmHg pressure was applied. Surgical procedures were performed using a full-thickness lateral approach (Fig. 1A). Through a lateral skin incision, the calcaneus was exposed. And then, through the design of pre-operation, closing wedge osteotomy was performed (Fig. 1B). According to the preoperative lateral radiograph of the calcaneus, the design of pre-operation taking into account the angle, width of the wedge, and orientation. When the osteotomy was completed with a shorter blade, the calcaneus was xed with full threaded cannulated screws under the guidance of 2 K-wires (Fig. 1C). When xation was nished, using a C-arm device to recon rm the position of the screws. Then, using a 2 − 0 absorbable suture to repair subcutaneous tissue, and using a 3 − 0 nonabsorbable suture to close the skin.

Postoperative Management
All patients were not allowed to walk for two weeks. All patients were allowed to perform passive motions of the ankle. Skin sutures were removed 2 weeks after surgery. At 8 weeks postoperatively, partial weight bearing was allowed in the removable walker boot. Patients were allowed full weight bearing at 3 months postoperatively.

Clinical And Radiographic Evaluations
Functional evaluations, pain assessments, evaluation of ankle joint, and anatomy changes were collected. Results of the functional evaluations, pain assessments and evaluation of ankle joint performed preoperatively and postoperatively (last follow up visit) were included to determine the Foot Ankle Society ankle-hindfoot scale (AOFAS) [14] , Visual Analogue Scale (VAS) [15] , and ankle range of motion (AROM). Results of anatomy changes included changes in the Chauveaux-Liet (CL) angle [3] (Fig. 2).

Statistical analysis
All data were analyzed statistically using SPSS (version 22.0; IBM, Chicago, IL). Paired t-tests were used to compare the outcomes measures (AOFAS, VAS, ROM and CL angle) recorded before surgery and at last follow-up visit. All values assessed were expressed as the mean ± standard deviation (SD). Statistical signi cance was de ned at P<0.05.

Discussion
In our study, the AOFAS, VAS, DAROM, and CL angle was signi cantly improved at the nal follow-up (P 0.01). The ZO showed signi cant function improvement and pain relief, and no patient were found with infection or nonunion. In another study found that the ZO showed signi cant pain relief compared to other surgical procedures [16] . And in study of Maynou [17] , the ZO was also reported has an excellent results.
Haglund deformity is common, which is an abnormality of the posterosuperior part of the calcaneus [2] . Because the enlargement of the posterolateral heel is near the insertion of the AT, the soft tissue and tendon are compressed during ankle motion [18] . This symptom is referred to as HS. This impingement of ankle motion is considered the main reason of HS [19] . Treatment should start off with conservative ways, such as activity modi cation, ice, or footwear modi cation. When conservative treatments fail, surgical treatment is required to remove the impingement. However, the posterosuperior prominence resection of tradition cannot solve the impingement between the calcaneus and the insertion of the AT. But the dorsal closing wedge calcaneal osteotomy can remove this impingement. Therefore, the ZO is not only no need for additional resection of the Haglund deformity, but also helpful to relief pain of the impingement.
Previous studies showed the good clinical result with ZO for HS [17] . But it is not to be noted from 1939 article of Zadek to 1965 study of Keck and Kelly, because of the high rate of postoperative complications [3] . However, the latest researches show that complications after calcaneal osteotomy is rare, and no signi cant difference has been found between traditional open operation and minimally invasive approach [20,21] . In study of Andrea [22] and Zilu Ge [10] , they found the ZO had a excellent clinical results for HS. And nonunion after ZO was not found for all patients. The mechanism of ZO is likely to elevate the insertion of the AT, and the orientation of the AT was changed. These biomechanical changes can reduce tendon stress and delay the progress of HS and eliminate risk factors [3] . In our study, the CL angle decreased from 18.2 ± 1.3 preoperatively to 9.4 ± 2.1 degrees postoperatively. The changes of the CL angle could prove it.
In this study, we rstly researched the changes of the AROM preoperatively and postoperatively. The ZO showed signi cant improved in the AOFAS, VAS, DAROM, and CL angle. However, we found that the PAROM is not signi cant changed after surgery. The changes of ROM were different. We thought that the main reason has to do with the AT. The AROM is affected by the AT, especially the PAROM. The changes of postoperative DAROM could also prove the advantage of ZO in biomechanical changes. The good clinical results may be attributable to the advantage of ZO.
This study comes with several limitations. This is retrospective design, the small sample size, and the short follow-up. Despite these limitations, and for all we know, this study rstly researched the changes of

Declarations
Availability of data and materials All data and materials regarding the study are available from the corresponding author.

Ethics approval and consent to participate
This study was approved by the Clinical Academic Committee of the Honghui Hospital, Xi'an Jiaotong University and conducted in compliance with the Helsinki Declaration. Written consent was acquired for all patients.

Consent for publication
Not applicable.

Competing interests
The authors declare that they have no competing interests.

Funding
None.
Authors' contributions ZWX designed the study, analysed the data, and wrote the manuscript. DJH, LJQ, and ZY collected the data and helped write the manuscript. ZHM and LXJ contributed to research design and revision of the manuscript. All authors read and approved the nal manuscript.