We assessed the long-term (20 years) outcome
of closed reduction and immobilisation in 19 patients with an isolated
fracture of the posterior malleolus of the ankle treated at a single
hospital between 1985 and 1990. The assessments used were an Olerud
functional questionnaire score, physical examination using a loaded
dorsal and plantar range of movement measurement, radiological analysis
of medial joint space widening, the Cedell score for anatomical
alignment of all three malleoli, and the radiological presence of
osteoarthritic change. There were excellent or good results in 14 patients (74%) according
to the Olerud score, in 18 patients (95%) according to loaded dorsal
and plantar range of movement assessment, in 16 patients (84%) as
judged by the Cedell score, and for osteoarthritis 18 patients (95%)
had an excellent or good score. There were no poor outcomes. There was
no correlation between the size of the fracture gap and the proportion
of the tibiotalar contact area when compared with the clinical results
(gap size: rho values -0.16 to 0.04, p ≥ 0.51; tibiotalar contact
area: rho values -0.20 to -0.03, p ≥ 0.4). Conservative treatment
of ‘isolated’ posterior malleolar fractures resulted in good clinical
and radiological outcome in this series at long-term follow-up.