Equivalent Outcomes for Patients Following Trochleoplasty as a Primary or Revision Patellar Stabilizing Procedure

OBJECTIVES: Patients with trochlear dysplasia often undergo primary procedures other than a trochleoplasty for recurrent patellar instability. When these other procedures fail and a trochleoplasty is performed, it is unknown if these patients do as well as those that had a trochleoplasty as their primary operation. The purpose of this study was to compare the clinical outcomes after trochleoplasty for severe trochlear dysplasia between a group of patients who previously underwent surgery for patellar instability to a group who underwent trochleoplasty as their initial procedure. METHODS: In this prospective cohort study with IRB approval, 40 patients who underwent a sulcus-deepening trochleoplasty as well as additional related procedures with at least one year follow-up were divided into two cohorts: 1) patients with prior surgery for patellar instability (n=19) [Table 1] and 2) patients with no prior surgery for patellar instability (n=21). Preoperative and postoperative IKDC and Kujala scores, in addition to patient satisfaction scores, recurrent dislocation events, and reoperations were compared between the two cohorts. RESULTS: 33 females and 7 males with an overall average age of 20.4 years with an average follow-up of 2 years were included in the study. Compared to preoperative scores, significant increases were seen in the postoperative IKDC and Kujala scores in both the primary (26.9 +/- 24.3, 21.5 +/- 22.3, respectively) and revision cohorts (22.7 +/- 23.0, 12.7 +/- 15.7, respectively) [Table 2]. There were no significant differences between outcome scores between cohorts with regard to final scores (p=0.661, 0.810, respectively) or absolute improvement (p=0.624, 0.284, respectively). There were no episodes of recurrent instability in either cohort. 23.8% of the primary cohort and 26.3% of the revision cohort underwent a secondary procedure for arthrofibrosis (p=0.420). There was no significant difference in satisfaction scores between the two cohorts, with an average score of 9.2 +/- 1.8 amongst all patients (p=.404). CONCLUSION: Patients with severe trochlear dysplasia will experience significant improvement postoperatively and will have equivalent outcomes if a trochleoplasty is performed as an index procedure or as a revision procedure following a prior failed patellar stabilizing procedure.