During the 1994 meeting of the Arthroscopy Association of North America, a review of 9 patients who had arthroscopic subtalar arthrodesis was presented.[13] Since then, many surgeons have performed arthroscopic subtalar arthrodesis in patients using supine or later positions through anterolateral and posterolateral portals.[13],[14],[15] Long-term follow-up for the treatment of ankle arthritis through the arthroscopic procedure used in ankle arthrodesis offered long-lasting results.[16],[17] Excessive stiffness in the soft tissues might make it impossible for the reduction. Thus, while patient is under general anaesthesia, intraoperative fluoroscopy and stress radiography, combined with clinical examination are performed to determine whether deformity is correctible before the surgical procedure. It is necessary to inform the patient that the presence of coronal ankle malalignment correction will be done arthroscopically by fusion. Sometimes, the deformity in some patients seems to be uncorrectable arthroscopically. Therefore open surgery will be done and patients ought to have been briefed already.
Debridement posterior to interosseous ligament and removal of the cartilage of posterior subtalar joint was done; it was a standard practice, commonly performed by fusing posterior facet in arthroscopic isolated subtalar arthrodesis allowing for proper bony fusion of the subtalar arthrodesis. [18],[19],[20],[21] Furthermore, we should bear in mind that persistent talar tilt may promote hindfoot destabilization and the development of peritalar instability, hence talar rotation has been shown to be critical for appropriate ankle fusion.[22]
Arthroscopy is not recommended if a joint is misaligned. Nonetheless, some investigators attempted to go on with the procedure. [12],[23] In all arthroscopic fusion procedures, it is necessary to apply force under the foot in an upward direction, which helps in maintaining compression on the talus and the tibia as described in other studies.[17] There are over 40 techniques reported in the literature, such as external fixation devices, intramedullary nails (IMNs), open crossed screw constructs and plates. [24],[25] Knowing the indications and contraindications for arthroscopic arthrodesis, only screws are usually chosen. Ferkel et al. [26],[27] described the insertion of two cannulated screws, one from the medial malleoli and the other from the lateral malleoli. Other researchers employed two screws that originated from the posterior part of the malleoli and were oriented 30° inferiorly and 30° anteriorly via two cannulated percutaneous ACE 6.5-mm screws. The screws were maintained parallel on both AP by entering them medially from the tibia into the talus, as described by Winson et al. [12], and the lateral views may be seen on imaging. Arthrodesis was repaired using four 6.5-mm cancellous lag screws, according to Zwipp et al. [28]
Contrarily to the other methods, our technique uses three cannulated percutaneous screws of 7.0 mm to achieve arthrodesis. We received 100% union rate by placing all three screws in inverted triangle shape manner appearances of screws in anterior posterior view of foot in in flouroscpoie. This technique is an essential step as the release of the deltoid ligament can help clean the osteophyte and stabilize the screws to correct deformities obtained through the lateral gutter, which allows us to fix even larger degrees of deformities. We used a modified Mazur Grading System to evaluate the ankle union as shown in Table 3. ([29]
Table 3
Modified Mazur Grading System
Excellent
|
80–90 points.
|
Good
|
70–79 points.
|
Fair
|
60–69 points.
|
Poor
|
< 60 points
|
In this grading scale system, 100 points means a perfect result. Note that the ankle motion scores up to 10 points. During the evaluation in our patients for arthrodesis, we achieved a maximum score of 90 points. In this Mazur ankle grading scale, out of 90 points, we gave 50 points for the pain. Other various factors were included in the Mazur ankle grading scale scoring system, such as; the use of support, function of foot, walking distance ability, ability to climb up and down the stairs, ability to walk up and down the hill.
This unique configuration is our innovative idea to achieve arthroscopic fusion for varus ankle arthritis larger than 25 degrees through the lateral gutter by releasing the deltoid ligament (Fig. 7). Compared to external fixation, internal fixation may provide a higher fusion rate and earlier recovery even for the greater degree. This method is more beneficial to patients and avoids serious complications, such as soft tissue infections.[30] Indications of the procedure may vary in different cases, like patients with ankle instability, neurological conditions, post-traumatic conditions, idiopathic cases, and we did this procedure on only correctable malaligned arthritis of the ankle. Contraindications of the procedure if patients have an active infection, have larger bone defects in some cases, stiff malalignment of the joint, autologous grafting or arthroplasty was contraindicated, and revision on previous non-union joints.