2023 ISAKOS Biennial Congress ePoster
Soft Tissue Patella Tendon Distalisation In the Skeletally Immature Patient: A New Technique and Case Series
Peter T. Annear, FRACS(Orth), Swanbourne, WA AUSTRALIA
Elizabeth G Garcia, MBBS, BSc, DML, Cottesloe, WA AUSTRALIA
Sarah Van Oudtshoorn, MBBS, Perth, Western Australia AUSTRALIA
Jay R. Ebert, PhD, Perth, WA AUSTRALIA
Perth Orthopaedics and Sports Medicine Centre, Perth, Western Australia, AUSTRALIA
FDA Status Not Applicable
Summary
Ten skeletally immature patients (13 knees) with recurrent patellofemoral instability due to patella alta and trochlea dysplasia underwent apophyseal sparing patella-tendon distalisation in combination with MPFL reconstruction showed satisfactory stability outcomes without apophyseal injury at 2 year follow-up.
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Abstract
Introduction
Patella instability in skeletally immature patients can affect athletic performance and involvement in sports. Major anatomical factors for recurrent instability include trochlear dysplasia, patella alta and lateralisation of the tibial tubercle, patella tilt and ligamentous laxity. After medial patellofemoral ligament reconstruction alone recurrence rates are high. Children and adolescents with recurrent instability undergoing stabilisation surgery may benefit from patella distalisation in the presence of patella alta. Bony tibial tubercle osteotomy is not recommended due to risk of damage to the tibial tubercle apophysis and resulting genu recurvatum deformity or leg length discrepancy. Surgeons must either delay surgery until skeletal maturity or use physeal sparing techniques to avoid premature physeal closure and growth arrest. There is no literature to demonstrate surgical or patient reported outcomes for such techniques. This study aims to demonstrate the safety, efficacy and patient reported outcomes for a novel surgical technique to address patella alta and instability in the skeletally immature patient.
Technique:
The patella tendon is sharply dissected with 2mm of apophyseal tissue and distalised based on soft tissue tension and patella engagement in the trochlear groove on arthroscopic assessment. Patella distalisation is coupled with physeal sparing medial patellofemoral ligament (MPFL) reconstruction with a two-limb gracilis autograft looped around and sutured to the medial collateral ligament (MCL) and superomedial patella periosteum. Synthetic fibre tape protects the extensor mechanism during healing.
Methods
A retrospective case series of this technique reviewed in 13 knees in ten patients, operated on by the senior author (PA). Radiology and medical charts were reviewed for demographic and surgical information and outcomes. Patients were reviewed for clinical examination and patient reported outcome measures. Institutional ethics was obtained from the University of Western Australia and Perth Children’s Hospital.
Results
Thirteen knees in ten patients underwent the procedure. Median follow up was 24 months (3.5-36 months). No patients had evidence of extensor mechanism dysfunction, growth arrest or lower limb deformity. Two patients had complications including superficial infection and recurrent instability. Radiographically there is a statistically significant improvement in Caton-Deschamps ratio for patella alta from pre-operative to post-operative radiographs.