Post-traumatic ankle arthritis is very common in clinical practice and is increasingly affecting young adult patients. But a suitable treatment modality for young adult patients is very challenging [6]. Various surgical treatment regimens have been used in clinical practice [9, 12][13][14][15][16]{Kim, 2021 #21;Lindsey, 2020 #25;Liu, 2020 #20;Ma, 2020 #26;Woo, 2020 #34;Zeininger, 2021 #18}, but the optimal option remains unclarified. The present study retrospectively analyzed 73 patients with severe post-traumatic ankle arthritis treated with either ankle distraction arthroplasty or supramalleolar osteotomy. The results suggest that both surgical methods can effectively treat traumatic ankle arthritis and relieve pain symptoms, especially in the early stage; However, in the long-term follow-up, the supramalleolar osteotomy was highly evaluated in ankle function score and patient satisfaction.
The pain in ankle arthritis is caused by fluid from the joint entering the subchondral bone due to pressure[17]. While ankle distraction arthroplasty could reduce the abnormal mechanical stress of the ankle through physical means, promote the intermittent flow of synovial fluid in the joint, proteoglycan metabolism, reduce inflammatory reaction, repair cartilage atrophy, and then enhance bone repair activity and increase the thickness of articular cartilage and therefore slow down the degeneration of ankle cartilage [18]. Ankle distraction arthroplasty can be a pre-treatment before ankle fusion or replacement surgery in young patients. This procedure has proved to be effective in relieving pain and restoring the ankle function [19][20][21][22][23]; Marijinissen et al [24] followed up 11 patients for at least 2 years after arthroplasty and reported significant improvements in pain and functional scores, suggesting that arthroplasty significantly relieve pain, preserve joint range of motion, and delay or reverse trauma. However, the relatively low effective rate, inconvenience and longer period of treatment may limit its more extensive use in practice [25]. Additionally, the gradually lowering postoperative satisfaction over time should be considered and for patients with obvious ankle valgus deformity, ankle joint distraction arthroplasty alone cannot correct the deformity.
In the early postoperative period, although ankle symptoms were significantly improved, and we did not find the significant difference in overall satisfaction rate and ankle function score. At the last follow-up, However, the tendency towards lower value in those treated by ankle distraction arthroplasty (excellent and good rate of 65.6% versus 97.5% for supramalleolar osteotomy). This may be caused by the higher rate of complications associated with ankle distraction arthroplasty, including sinus tract infection, fixation failure, difficulty in moving after surgery, and the need for frequent reviews and external fixation adjustments [19].
The superiority of supramalleolar osteotomy over distraction arthroplasty is the ability to correct the load line of the ankle and hindfoot and to correct the distal tibial deformity in the coronal and sagittal planes[26][27]. Supramalleolar osteotomy could transfer the stress to the cartilage area that is normal or not been seriously degraded by the means of adjusting the force line of the tibia. In this study, supramalleolar osteotomy proved to better correct talus varus deformity and restore the lower limb alignment, consistent with the previous findings [28][29], therefore, facilitating delaying the further development of ankle arthritis. Of note, patients with chronic ankle instability caused by severe injury or repeated multiple injuries may develop increased stress in the asymmetric joint spaces, forming painful asymmetric ankle arthritis and ankle point mismatch [30], thus additionally requiring osteotomy surgery to restore the lateral stability [31].
The second advantage of supramalleolar osteotomy is the relatively lower rate of postoperative complications, with postoperative ankle stiffness as the primary one. Others reported complications involved bone union issues at the osteotomy site, and surgical wound related issues, such as dehiscence and infection. In the present study, we reported an average overall complicate rate of 7.3% [32][33]. Despite the above-mentioned advantages, supramalleolar osteotomy was not overwhelmingly recommended, partly due to the need for a second operation to remove the internal fixation material.
In this study, osteophyte removal of the ankle joint and release of the achilles tendon or gastrocnemius muscle were performed. This surgical method can fully expose the ankle joint and completely remove the hyperplastic osteophyte and synovial tissue; although this surgical method is an adjuvant operation However, to a certain extent, it delays the development of the ankle joint, improves the range of motion of the ankle joint, restores the function of the ankle joint, and improves the success rate of the operation [34][35]. This further ensures the effectiveness of surgical treatment. It is worth noting that damage to the superficial peroneal nerve should be avoided during the procedure.
This study suffered from several limitations. First, the retrospective design might impede the accuracy and precise in collecting the data and these data cannot be verified. The use of average values for some outcome measures conducted by 3 independent investigators might compensate for this limitation. Second, due to the limited use in our institution, we included only 73 eligible patients for data analysis, making the comparison not definitely conclusive. It is possible the true differences for some outcome variables are withheld to detect by such limited sample, namely the type Ⅱ statistical error. Third, these operative procedures were completed by general orthopaedic surgeons (n=7) and foot and ankle surgeons (n=4), in whom the experience can be different, thus affecting the results. Also, due to the very limited number of procedures for a certain surgeon, we could not make a direct comparison between them. Fourth, this is a single-certain study, limiting the generalizability of our results to other settings. The well-designed large sample studies are warranted to verify our results and to provide a robust evidence for improving the management of this chronic bone condition.