Deepening Trochleoplasty With a Thick Osteochondral Flap for Patellar Instability: Clinical and Functional Outcomes at a Mean 6-Year Follow-up.
BACKGROUND
In patients with patellar instability and severe trochlear dysplasia, trochleoplasty has become increasingly used as part of its surgical management.


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


METHODS
Case series; Level of evidence, 4.


METHODS
Between 1995 and 2010, deepening trochleoplasty with a thick flap was performed in 90 patients (107 knees) with severe trochlear dysplasia. Data were collected prospectively preoperatively, at 6 weeks, and at 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
The average follow-up was 6 years (range, 2-19 years). The median Kujala score was 63 (interquartile range [IQR], 47-75) preoperatively, rising to 79 (IQR, 68-91) at 1-year follow-up and 84 (IQR, 73-92) at final follow-up (P < .05). Seventy-two percent were satisfied with their knee function at 1-year follow-up, rising to 83% at final follow-up (P < .0001). Sports and exercise participation increased from 36 patients (40%) preoperatively to 60 (67%) at final follow-up. The number of patients involved in competitions increased slightly from 10 (11%) to 11 (12%). Of those sports that involved twisting (e.g., soccer, cricket, badminton), the number of patients participating increased from 16 (18%) to 22 (24%), whereas in nontwisting sports (e.g., running, swimming, cycling), it increased from 24 (27%) to 47 (52%), of whom 12 (16%) used walking as exercise. Two patients who had undergone medial patellofemoral ligament (MPFL) reconstruction as the index operation needed the MPFL revised, and a further 8 patients needed MPFL reconstruction subsequently for instability symptoms and a mediolateral glide in extension of more than 2 quadrants' displacement. At final follow-up, no patient had mechanical patellofemoral instability.


CONCLUSIONS
Deepening trochleoplasty with a thick flap improves clinical and functional outcomes for patients with symptomatic patellar instability with severe trochlear dysplasia. These results improve over time and beyond 1-year clinical follow-up. However, trochleoplasty does not lead to a significant improvement in sports participation at a competitive level. It does improve patient participation in sports and exercise, principally in nontwisting sports activities.
Department of Orthopaedics, Norfolk and Norwich University Hospital, Norwich, UK.
Iain
I
McNamara
Faculty of Medicine and Health Sciences, University of East Anglia, Norwich, UK.
Nelson
N
Bua
Faculty of Medicine and Health Sciences, University of East Anglia, Norwich, UK.
Toby O
TO
Smith
George Washington University School of Medicine & Health Sciences, Washington, District of Columbia, USA.
Khameinei
K
Ali
Department of Orthopaedics, Norfolk and Norwich University Hospital, Norwich, UK simon.donell@nnuh.nhs.uk.
Simon T
ST
Donell
D000293:Adolescent; D000328:Adult; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007593:Joint Instability / Q000601:surgery*; D007719:Knee Joint / Q000601:surgery*; D008022:Ligaments / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013177:Sports; D055815:Young Adult
clinical outcomes; midterm; patellar dislocation; sports; trochleoplasty