Other authors who have described their experiences in dealing with severe joint limitations have also carried out arthroplasty in young patients. Schurman et al. described arthroplasty of an ankylosed knee in the case of a 24-year-old patient. Given the young age of these patients and the possible need for future revision, we sought to perform arthroplasty in the least aggressive manner possible. For this, we used prostheses without posterior stabilization, and we did not replace the patella, since there was less bone resection.
Aglietti et al. described their experience in treating knees with severe joint limitations using prostheses with posterior stabilization. We believe that, although the bone resection and consequent ligament resection are extensive in cases of ankylosis, the anteroposterior stability in this group of patients is less important, due to the limitation of movement that consistently remains.
Postoperative rehabilitation was carried out by a physiotherapist. We did not use continuous movement equipment, since we judged that it was not necessary to detect any adherence or movement restriction within the first 72 hours", since we judged that it was necessary to detect any adherence or movement restriction within the first 72 hours. If any limitations were present, the intensity of the manipulation could have been immediately increased. Manipulation of postoperative joint limitations should be performed as early as possible, as suggested by Yercan et al.
Improved movement was observed in all of our patients, although a limitation of five degrees of extension occurred in four patients, and the mean flexion gain was 65 . Naranja et al. described a mean flexion gain of 62  in a multicenter study. Rajgopal et al. reported a mean flexion gain of 61  in 84 knees of 54 patients who presented severe joint limitation.
A significant reduction in pain was observed in all our patients, in addition to gains in movement. However, we were unable to reestablish normality for any of the cases.
From a two-year follow-up of a series of nine cases similar to ours, Bradley et al. considered their results to be satisfactory with regard to reductions in pain and partial gains in movement.
Rajgopal et al. presented a series of 84 knees among 53 patients with severe joint limitation. After a mean follow-up of nine years, they considered their results to be good because their patients experienced reduced pain and improved quality of life.
In the present study, two serious complications that required extensive revision occurred. Both were due to infections, and one of our patients developed ankylosis as a consequence of infection.
Kim et al. performed arthroplasty in 16 patients with ankylosis of the knee following pyogenic infection or tuberculosis. In most of those cases, the results were satisfactory, with postoperative infection occurring in just two cases.
In a multicenter study of 35 patients who underwent total arthroplasty of their ankylosed knees, Naranja et al. reported an early complication frequency of 24% and a major complication frequency of 35%. The frequency of infection was 14% in their group of patients.
There is no doubt that arthroplasty of ankylosed knees is a risky procedure, and this limitation must be clearly laid out for potential patients. Nevertheless, the possibility of gains in movement and significant reductions in pain may compensate for the risks.
The evident shortcoming of the present study is our small number of cases, which precluded the ability to obtain definitive conclusions.
In the event of complete failure in the attempt to perform arthroplasty, we would have performed arthrodesis, the only procedural indication for this group of patients other than arthroplasty.
However, based on the latest follow-up, there had been no need to perform arthrodesis for any of our patients.