lass="h4">Background
The association of pate
llar and troch
lear anoma
lies resu
lting in iso
lated pate
llofemora
l osteoarthritis has often been postu
lated but rare
ly studied. The purpose of this study was to examine the association of pate
llofemora
l dysp
lasia, specifica
lly troch
lear anoma
lies, which are a cause for degenerative disease and may resu
lt in a worse outcome after arthrop
lasty for iso
lated pate
llofemora
l arthritis.
lass="h4">Methods
Eighteen consecutive patients who underwent robotic image-based patellofemoral arthroplasty were compared with an age and sex-matched group of patients who underwent medial unicompartmental arthroplasty using the same image-based navigation system and had no patellofemoral, lateral disease or malalignment.
The compared parameters were the patellofemoral-trochlear angle and Dejour score in the preoperative radiographs and patellofemoral-trochlear angle and internal rotation of the trochlea compared to the intercondylar line in the proximal, middle and distal trochlea.
lass="h4">Results
Significantly higher rates of patella alta (T = 5, P = 0.0001) and trochlear dysplasia (6% vs. 55%) were found, as manifested by an increase in the trochlear angle and Dejour score. Furthermore, the trochlea was found to have a higher degree of internal rotation in patients with isolated patellofemoral arthritis compared to the control group.
lass="h4">Conclusions
In conclusion, patellofemoral anomalies such as patella alta and trochlear dysplasia are present in association with isolated patellofemoral arthritis. Isolated patellofemoral arthritis is also associated with higher rates of trochlear internal rotation. Correction of this internal rotation is essential in the success of arthroplasty in patients with patellofemoral disease.
lass="h4">Level of evidence
Level III study, It is a case control study.