Upward fixation of the patella in the horse. A retrospective study.

The objective of the present study was to assess the incidence of upward fixation of the patella (UFP) in different types of patients and to evaluate the outcome of conservative and surgical treatment for correcting this condition. A particular attempt was made to find out whether corrective trimming and/or shoeing (CTS) is efficient in the conservative treatment of UFP, and whether a longer postoperative resting period reduces the risk of complications after medial patellar desmotomy (MPD). Medical records of 78 horses with intermittent or permanent UFP were analyzed retrospectively. Young animals and ponies were mostly affected, mainly during winter (P < 0.05). Seventy-six horses with UFP were treated conservatively, with follow-up being possible in 64 of them. This treatment, in which CTS seemed the most important aspect, was fully successful in 51.6% of these patients; 20.3% of them improved partially. In case of no response to conservative treatment, or in case of a permanent fixation, MPD was performed in 20 horses, which corrected UFP completely in 17 of the 18 followed-up patients. However, gait abnormalities were seen in seven of those 17 horses postsurgically, but with the incidence being lower in horses that had rested for at least three months (25%) compared to horses that had only rested for less than one month (66.6%). Results indicate that conservative treatment, with special attention for CTS, is worth trying before performing more radical procedures to correct UFP, and that a longer convalescence period after MPD is desirable.