Although several surgical treatments for patellar instability with patella alta have been reported, the clinical outcomes and optimal surgical procedures for patellar instability with patella alta in middle-aged patients are still controversial. We hypothesized that optimal surgical procedures for patellar instability with patella alta in middle-aged patients may induce good clinical outcomes with better patellofemoral geometry.

Twelve middle-aged patients with a mean age of 44 years (range: 40–55 years), who presented with patellar instability and patella alta, were treated with a combination of several surgeries, such as medial patellofemoral ligament (MPFL) reconstruction, trochleoplasty, lateral release, and three-dimensional transfer of the tibial tuberosity, based on a surgical algorithm. Patellar position and clinical outcomes were evaluated postoperatively. The mean follow-up time was 41.5 months (range: 24–72 months).

Patellar position altered from 1.31 (1.21–1.53) preoperatively to 0.88 (0.69–1.06) postoperatively on the Caton-Deschamps Index (p<0.01). The tibial tuberosity–trochlear groove (TT-TG) distance altered from 21.8mm (20.1–25.8mm) to 10.3mm (5.1–14.7mm), and patellar tilt ranged from 28.1° (21–40°) to 14.6° (5–28°), respectively (p<0.01). Clinical outcomes on the Lysholm and Kujala scales improved from 43.1 and 38.4 to 86.7 and 78.3, respectively, at final follow-up (p<0.01). Surgical treatment that included trochleoplasty resulted in better outcomes than other surgical combinations without trochleoplasty (p<0.05). Sulcus angle and postoperative patellar tilt improved more in those who underwent trochleoplasty than in those who did not (p<0.05).

Surgical treatment for patellar instability with patella alta in middle-aged patients resulted in improved clinical outcomes. In particular, a combination surgery including trochleoplasty resulted in the greatest improvement in case of severe trochlear dysplasia.

IV. Retrospective case series study.