Abstract
Background: Patellar height has long been considered a risk factor for patellofemoral instability. However, recent pediatric literature demonstrated a reduction in patellar height measurements following medial patellofemoral ligament (MPFL) reconstruction. Purpose: To assess the mean change in patellar height and the percentage of skeletally mature patients with patellar height ratios reduced to within-normal limits following MPFL reconstruction. Study Design: Case series; Level of evidence, 4. Methods: Adult patients undergoing primary MPFL reconstruction for recurrent lateral patellar instability between 2005 and 2013 were identified. Pre- and postoperative (within 1 year of surgery) lateral knee radiographs were assessed for patellar height indices, including Caton-Deschamps, Blackburne-Peel, and Insall-Salvati ratios. The change in patellar height and the number of patients reduced from abnormal to normal patellar height ratios following MPFL reconstruction were assessed. Results: Overall, 32 adult patients were included in the study, with a mean age of 25.7 years (range, 18-55 years). There were 21 women (66%) and 11 men (34%). Insall-Salvati, Blackburne-Peel, and Caton-Deschamps ratios all demonstrated significant reductions in patellar height between pre- and postoperative lateral knee radiographs (P <.001). All 3 indices showed a reduction in the number of patients meeting the criteria for patella alta following MPFL reconstruction. A total of 64% of patients had an abnormal preoperative Caton-Deschamps ratio reduced to within normal limits postoperatively. Conclusion: MPFL reconstruction provides a consistent reduction in patellar height measurements. The Caton-Deschamps ratio was reduced to the reference range following MPFL reconstruction in 64% of patients with preoperative patella alta. Surgeons treating patellofemoral instability should expect a reduction in patellar height after ligament reconstruction, which may affect the need for more invasive distalization procedures.
Original language | English (US) |
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Article number | 2325967117751659 |
Journal | Orthopaedic Journal of Sports Medicine |
Volume | 6 |
Issue number | 1 |
DOIs | |
State | Published - Jan 2018 |
Keywords
- MPFL reconstruction
- Patellar height
- Patellar instability
- Patellofemoral arthritis
ASJC Scopus subject areas
- Orthopedics and Sports Medicine