http://dx.doi.org/10.14517/aosm13010 Review Article pISSN 2289-005X·eISSN 2289-0068 Arthroscopically assisted ankle fusion Yoon-Chung Kim1, Jae Hoon Ahn2 1Department of Orthopaedic Surgery, St. Vincent’s Hospital, The Catholic University of Korea College of Medicine, Suwon; 2Department of Orthopaedic Surgery, Seoul St. Mary’s Hospital, The Catholic University of Korea College of Medicine, Seoul, Korea Ankle arthrodesis has been performed for the treatment of symptomatic ankle arthritis with reported complications such as nonunion, malunion and nerve injury. Arthroscopic ankle fusion has the advantages of minimal soft tissue damage, short fusion period, high union rate, and early rehabilitation. The authors describe the surgical technique and the advantages and disadvantages of arthroscopically assisted ankle arthrodesis. Keywords: Ankle arthritis; Ankle fusion; Arthroscopy INTRODUCTION OVERVIEW In spite of being one of the main weight-bearing joints Indications of the body, the ankle is relatively resistant to the The indications for arthroscopic ankle arthrodesis are similar development of primary osteoarthritis. The majority of to those for conventional open arthrodesis [3]. The primary ankle arthritis is secondary to trauma, such as a fracture, indication is end-stage degenerative arthritis of the ankle ligament injury, and cartilage damage. Inflammatory that does not respond to conservative therapy, including arthropathies including rheumatoid arthritis and avascular medication, bracing, and orthotics. Other indications necrosis of the talus also can lead to the development include septic arthritis, rheumatoid (inflammatory) arthritis, of arthritis in the ankle. Ankle arthrodesis has been avascular necrosis with less than 30% of involvement of the considered as one of the standard surgical treatment talus, failed total ankle replacement, deformity resulting options for severely painful ankle arthritis refractory from neuromuscular disease, and severe joint instability to conservative management [1]. It produces relatively [4,5]. The arthroscopic procedure can be useful when open satisfactory results, and thus has been widely performed. arthrodesis is not feasible due to poor soft tissue condition More than 40 different surgical techniques are available and scarring. for ankle fusion, including conventional open arthrodesis, mini-open arthrodesis, and arthroscopically assisted Contraindications arthrodesis. Of these, arthroscopically assisted arthrodesis, Arthroscopic arthrodesis has not been recommended for first introduced by Schneider [2] in 1983, has been more ankles with a severe varus/valgus deformity due to the frequently performed due to improved arthroscopic difficulty of joint surface preparation and the necessity of surgical techniques and instrumentation. extensive bone resection to achieve neutral ankle position [4]. Although it can be considered as an option in the Received August 1, 2013; Revised September 26, 2013; Accepted October 8, 2013 Correspondence to: Jae Hoon Ahn, Department of Orthopaedic Surgery, Seoul St. Mary’s Hospital, The Catholic University of Korea College of Medicine, 222 Banpo-daero, Seocho-gu, Seoul 137-701, Korea. Tel: +82-2-2258-2837, Fax: +82-2-535-9834, E-mail: jahn@ catholic.ac.kr Copyright © 2014 Korean Arthroscopy Society and Korean Orthopedic Society for Sports Medicine. All rights reserved. CC This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/ AOSM by-nc/3.0) which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Arthrosc Orthop Sports Med 2014;1(1):1-5 1 Yoon-Chung Kim, Jae Hoon Ahn. Arthroscopically assisted ankle fusion presence of less than 10o-15o of varus/valgus deformity, it achieved due to the presence of joint instability, a 4.0 is imperative for the surgeon to be highly experienced in mm diameter arthroscope can be used as well. The larger the conventional open arthrodesis to successfully carry diameter arthroscope may facilitate the arthrodesis, out the arthroscopic procedure. In the planning stage of because it provides wider and clearer view. Other the operation, the determination of a surgical technique instruments needed to address the articular surfaces should be based on the assessment of the alignment of include shavers, burrs, curettes, and osteotomes. the ankle using weight-bearing anteroposterior and lateral radiographs and the surgeon’s experience (Fig. 1A, B). Portal establishment and operative technique Avascular necrosis involving more than 30% of the After palpating the soft spot located medial to the tibialis talus is a relative contraindication for arthroscopic ankle anterior tendon, 10-15 mL of sterile saline is injected to arthrodesis. It can be better addressed with Blair tibiotalar distend the joint cavity. Then, arthroscopic portals are or tibiotalocalcaneal arthrodesis, because poor bone created. We prefer to use three portals (anteromedial, quality due to extensive avascular necrosis increases the anterolateral, and posterolateral portals) for ankle risk of nonunion [6]. Therefore, it is important to verify arthrodesis. Care should be taken to avoid damaging of the extent of avascular necrosis in the talus with imaging nerve branches, such as the superficial peroneal nerve, by modalities such as plain radiography, magnetic resonance delicately incising the skin only without penetrating the imaging, and bone scan prior to surgery. subcutaneous tissues during portal placement. This ‘nick Extensive bone loss, poor bone density, neuropathic and spread’ technique during portal placement can be arthropathy (Charcot arthropathy), and the presence of helpful for preventing nerve damage. The anteromedial acute infection are also known as contraindications for portal is established first, just medial to the tibialis anterior ankle arthrodesis [7]. tendon, because it is relatively easy to make and no major neurovascular structures exist. The anterolateral portal is Advantages created lateral to the peroneus tertius tendon, taking care Arthroscopic arthrodesis makes minimal soft-tissue to avoid the branches of the superficial peroneal nerve. damage around the ankle, and thus decreases the It is easy and safe to ensure the location by palpating incidence of complications, such as nonunion, post- the skin and observing the anterolateral aspect at the operative infection, and neurovascular damage. The same time with an arthroscope introduced through the arthro scopic procedure is advantageous over the open anteromedial portal. The posterolateral portal is placed procedure in terms of decreased time to fusion, post- 1-1.5 cm proximal to the tip of the lateral malleolus of the operative pain reduction, rapid rehabilitation, short fibula and just lateral to the Achilles tendon, avoiding the hospital stay, and reduced treatment cost [1,5,6,8-11]. In course of the sural nerve. It usually serves as an inflow addition, it allows for future total ankle replacement by portal that allows optimal visualization. The anteromedial minimizing the damage to the periarticular structures. and anterolateral portals can be used alternately for either arthroscopic viewing or for resection of the synovial OPERATIVE TECHNIQUE tissue, osteophytes, articular cartilage, and subchondral bone with a shaver or a curette. Meticulous debridement Instrumentation and setup and resection of articular cartilage and subchondral For successful arthroscopy, sufficient distraction should bone of the talar dome and distal tibia are performed. To be applied to the ankle joint to expand the joint space. determine the adequacy of debridement and resection, Currently, noninvasive distraction devices with use of the the sufficient punctate bleeding should be confirmed straps around the midfoot and hindfoot are commonly on the bony surfaces after the infusion pump turned off used. Noninvasive distraction can be applied with the momentarily (Fig. 1C). Then a guide pin for a 6.5 mm patient in the supine position by taking (1) the extension cannulated screw is inserted into the medial aspect of of the knee, (2) the flexion of the hip and the knee using the distal tibia and lateral aspect of the distal fibula under a thigh holder, or (3) the flexion of the knee far down on arthroscopic view using a drill guide such as Microvector the operating table. In general, a short arthroscope with (Smith Nephew Endoscopy, Andover, MA, USA). After a diameter of 2.7 mm and an obliquity of 30o is used for removing the arthroscope and the distraction device, the arthroscopic procedure. If sufficient distraction can be surgeon ensures the contact of opposing joint surfaces by 2 www.e-aosm.org Yoon-Chung Kim, Jae Hoon Ahn. Arthroscopically assisted ankle fusion applying appropriate pressure with the ankle placed in The rehabilitation protocol consists of 6-8 weeks of non- neutral position in the sagittal plane, 0o-5o of valgus in the weight bearing short leg cast immobilization followed coronal plane, and 5o of external rotation in the transverse by weight bearing immobilization for another 2-4 weeks plane. Subsequently, the two guide pins are advanced until fusion is evident on radiographs. In most cases, into the talus for preliminary fixation. After ascertaining radiographic evidence of fusion is observed 8-12 weeks the position of ankle joint and the location of the guide after surgery, and thereafter, patients are permitted to