Risk of osteoarthritis secondary to partial or total arthrodesis of the subtalar and midtarsal joints after a minimum follow-up of 10 years

IntroductionThe goal of this retrospective, multicentre study was to evaluate the long-term outcomes in patients who have undergone partial or total arthrodesis of the subtalar and midtarsal joints.HypothesisSecondary osteoarthritis of the adjacent joints can negatively affect the outcomes more than 10 years after these fusion procedures.Material and MethodsThe outcomes of 72 fusions (total: 22; partial: 50) performed between 1981 and 2002 were evaluated using the Maryland Foot Score (MFS), self-evaluation questionnaire and three weight-bearing X-ray views (Meary's with cerclage wire around heel, lateral and dorsoplantar). The average follow-up was 15 ± 5 years (range 10–31).ResultsThere were two deep infections that resolved after lavage and antibiotics therapy. There were 21 early complications (10 complex regional pain syndrome, 7 delayed wound healing, 2 superficial infections, 2 venous thrombosis) that all resolved. There were five cases of non-union (6.9%) that healed after being re-operated. After five years, secondary osteoarthritis led to the fusion being extended to the tibotalar joint (1 case) and midtarsal joint (1 case). At the last follow-up, the average MFS was 71.5 (range 25–100). Patient deemed the result as either excellent (10%), very good (9%), good (55%), poor (19%) or bad (7%). Pain at the last follow-up was present in 84% of cases. The rear-foot was normally aligned in 45% of cases, varus aligned in 22% and valgus aligned in 33%. The MFS was significantly better in patients with normal alignment. Patients with neurological foot disorders had significantly more preoperative (80% cavovarus) and postoperative foot deformity (P<0.05). At the last follow-up, the rate of secondary osteoarthritis in the surrounding joints was elevated: 73% tibiotalar, 58.3% subtalar, 65.8% talonavicular, 53.5% calaneocuboid. The presence of osteoarthritis was not correlated with pain or lower MFS. However there was significantly more pain at last follow-up than at 12 months postoperative and two fusions were required in patients with secondary osteoarthritis.ConclusionAlthough partial or total arthrodesis of the subtalar and midtarsal joints is a reliable procedure, it induces secondary osteoarthritis. Even though it seems to be well tolerated more than 10 years after the initial procedure, this possibility must be discussed with young, active patients.Level of evidenceIV, retrospective study.