Introduction: Malrotation of prosthetic components have been widely recognised as a cause of knee prostheses failure. In the present study, we hypothesised that an algorithm including clinical and radiographic evaluation, as well as a computed tomography analysis with defined values, could be reliable for the preoperative diagnosis of knee prosthesis malrotation in order to advise our treatment. Materials and methods: For this purpose, current parameters and related literature were taken into account. We analysed 44 patients with anterior knee pain after total knee arthroplasty. Among them, 24 patients (17 females and seven males), aged 43 to 78 years (mean 67 years) were evaluated with computed helicoidal tomography, and subsequently treated in a different way according to severity of their problem. Eight patients with components rotation in the normal range and patients with mild combined external rotation of the prosthesis underwent patella arthroplasty; other 16 patients with malposition in internal rotation or more severe external rotation, underwent complete prosthetic revision. Discussion: After an average follow-up of 32 months (range 12 to 120 months) results assessed according to the Knee Society rating system showed excellent or good clinical outcome in 87% (21 out of 24 patients) and functionally in 75% (18 out of 24 patients) of cases surgically treated. The malposition of knee prosthetic components on the axial plane is an emerging problem, difficult to interpret, which provides various surgical options such as resurfacing of the patella in mild cases until the complete revision of the implant.
- Anterior knee pain
- Computed tomography
- Knee prosthesis revision
- Rotational malalignment
- Secondary patella resurfacing
ASJC Scopus subject areas
- Public Health, Environmental and Occupational Health