Methods

Seventeen consecutive patients (19 knees) with patellar instability secondary to trochlear dysplasia underwent trochleoplasty, of which 12 knees (12 patients) were radiologically evaluated pre- and post surgery using axial CT and MRI imaging. Their mean age at time of surgery was 28.1 years (15 to 44). The mean follow-up was 2.2 years (0.5 to 5). The following four radiological outcomes were used: trochlear depth (TD), transverse patellar shift (TPS), lateral patellar inclination angle (LPIA) and sulcus angle (SA). All knees were assessed post-operatively using MRI. The axial CT images were reformatted which allowed for direct comparison with MRI. Each knee was radiologically evaluated twice by a senior musculoskeletal radiology consultant to increase data accuracy and assess for intra-observer reliability using the intraclass correlation coefficient (ICC). Functional outcomes consisted of the KOOS, Lysholm, Kujala and Tegner scores.

Methods and Results

A prospective consecutive case series of sixty Uniglide UKRs was carried out in fifty-one patients between January 2006 and March 2009. The data collected included:

Primary outcome measures:

Pre- and post-operative American Knee Society Score (AKSS), Oxford Knee Scores (OKS), WOMAC

No cases were lost to follow-up. Mean follow-up time was 19 months (12 to 36months) and mean age was 66 years (39 to 78 years).

Kaplan-Meier Survivorship showed 95% survival at 3 years (CI:6.4).

All functional outcomes showed significant improvement p <0.05. There were two revisions within the first year, which were the main complications, secondary to aseptic tibial loosening and collapse of the posteromedial tibia. The x-ray error score identified the most common error as the femoral flexion/extension angle followed by the anterior/posterior fit.