Deepening trochleoplasty with a thick osteochondral flap for patellar instability: Clinical and functional outcomes at mean 6 year follow-up

Iain McNamara, Nelson Bua, Toby O. Smith, Khameinei Ali, Simon T. Donell (Lead Author)

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Background: In patients with patellar instability and severe trochlear dysplasia, trochleoplasty has become increasingly used as part of the surgical management.

Hypothesis: Deepening trochleoplasty for severe dysplasia in patellofemoral instability improves function and increases sports participation.

Study Design: Case series; Level of evidence, 4.

Methods: Between 1995and 2010 the thick-flap deepening trochleoplasty was performed in 90 patients (107 knees) with severe trochlear dysplasia. Data was collected prospectively pre-operatively, at 6 weeks and 1-year follow-up. The patients were surveyed retrospectively to determine the clinical and functional outcomes including sports and exercise participation at a minimum of 2 years, with complete data available in 92%.

Results: With a minimum follow-up of 2 years, average of 6 years (range 2 – 19 years). The Kujala score had a median and interquartile range (IQR) of 63 (47-75) pre-operatively rising to 79 (68-91) at 1 year follow-up and 84 (73-92) at final follow-up (p< 0.05). Seventy-two per cent were satisfied with their knee function at 1 year follow-up rising to 79% at final follow-up (p <0.0001). Sports and exercise participation increased from 36 patients (40%) pre-operatively to 60 (67%) at final follow-up. The numbers involved in competitions increased slightly from 10 (11%) to 11 (12%). Of those sports that involved twisting (e.g. soccer, cricket, badminton), the proportion of patients participation increased from 16 (18%) to 22 (24%), whereas in non-twisting sports (e.g. running, swimming, cycling) it increased from 24 (27%) to 47 (52%) of whom 14 (16%) used walking as exercise.

Conclusion: The thick-flap deepening trochleoplasty improves the clinical and functional outcomes for patients with symptomatic patellar instability with severe trochlear dysplasia. These results improve over time and beyond the 1 year clinical follow-up. However trochleoplasty does not lead to a significant improvement in sports participation at a competitive level. It does improve the sports and exercise patient participation, principally in non-twisting sports activities.
Original languageEnglish
Pages (from-to)2706-2713
Number of pages8
JournalAmerican Journal of Sports Medicine
Issue number11
Early online date3 Sep 2015
Publication statusPublished - Nov 2015


  • Patellar dislocation
  • Trochleoplasty
  • Mid-term
  • Clinical outcome
  • Sports

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