Dynamic-Anatomical Reconstruction of Medial Patellofemoral Ligament in Open Physis

Outcomes of an All-Soft Tissue Fixation Technique for Reconstruction of the Medial Patellofemoral Complex Using Double-Bundle Quadriceps Tendon Autograft for Recurrent Patellar Dislocation in Skeletally Immature Patients

Background

Patellar fracture, femoral physis injury, and recurrent instability are concerning complications in medial patellofemoral ligament (MPFL) reconstruction (MPFLR) techniques for recurrent patellar dislocation in children and adolescents.

Purpose

To evaluate the outcomes of an anatomic all-soft tissue fixation technique for reconstruction of the medial patellofemoral complex (MPFC) using a double-bundle quadriceps tendon (QT) autograft for recurrent patellar dislocation in skeletally immature patients.

Study Design

Case series; Level of evidence, 4.

Methods

This retrospective study involved 24 skeletally immature patients (24 knees; 16 women and 8 men; age range, 9.5-15 years) with recurrent patellar dislocation who underwent MPFC reconstruction using a double-bundle QT autograft between September 2018 and January 2021. Only soft tissue suture fixation was used on the femoral and patellar sides of the 2 bundles of the QT. Radiographs, computed tomography, and magnetic resonance imaging were used to evaluate physeal status, lower limb alignment, patellar height and tilt, trochlear morphology, tibial tubercle-trochlear groove distance, and any associated knee pathology. Functional outcomes were assessed with the Kujala score, the visual analog scale (VAS) for pain, and the grading system of Insall et al.22.

Results

The mean follow-up time was 40 ± 9.6 months (range, 28-56 months). At the final follow-up, the Kujala and VAS pain scores showed a significant improvement versus preoperative scores (P < .001), and the passive lateral patellar glide showed a significant reduction (P < .001). All patients had negative apprehension and J signs. Of the 24 patients, 23 regained full range of motion, while 1 patient had a knee flexion deficit. The patellar tilt angle improved significantly at the final follow-up (P < .001). There was no patellar fracture, femoral physis injury, or recurrence of patellar dislocation. According to the grading system of Insall et al, the results were excellent in 15 knees (62.5%), good in 8 knees (33.3%), fair in 1 knee (4.2%), and no knees showed poor results.

Conclusion

Reconstruction of the MPFC using a double-bundle QT autograft with an all-soft tissue fixation technique was an effective method for treating patellar instability in skeletally immature patients.

Outcomes of surgical treatment of patellar instability in children with Down syndrome

BACKGROUND

patellar instability is a relatively frequent musculoskeletal disorder in children with Down syndrome (DS). However, such a condition has seldom been studied in the literature, even less its surgical treatment. Different techniques have been offered for this condition; the evidence for surgical options is scarce and primarily based on case reports or case series with few patients and heterogeneous techniques. Given this background, we aimed to evaluate the outcomes of a uniform kind of surgical procedure for such a condition that combined lateral soft tissue release, medial patellofemoral ligament (MPFL) reconstruction (using a partial-thickness quadriceps tendon autograft), the Roux-Goldthwait procedure, and V-Y quadricepsplasty (if needed).

MATERIALS AND METHODS

This retrospective study involved 11 skeletally immature patients (12 knees; 9 males and 2 females), 5.5 to 14.1 years of age, with DS who had patellofemoral instability (PFI) and were managed by this technique between October 2018 and March 2020. Preoperative radiography, CT scan, and MRI were performed to evaluate the physis status, lower limb alignment, patellar height, trochlear morphology, and any associated knee pathology. A functional knee assessment was done by using the Kujala score and the modified Lysholm score.

RESULTS

The mean time of follow-up (± SD) was 47.7 ± 5.8 months (range: 39-56). Pre-operatively, the Kujala score (± SD) was 52.6 ± 14.3 (range: (31-74), and at final follow-up, it was 92.2 ± 4.4 (range: (88-98), showing a significant improvement (P < 0.001). The preoperative modified Lysholm score (± SD) was 54.3 ± 8.1 (range: 39-62), and at final follow-up it was 92.4 ± 5.3 (range: 82-96), showing a significant improvement (P < 0.001). All patients had a stable patella without a recurrence of instability and regained full ROM. There was no incidence of a patellar fracture or femoral physis injury.

CONCLUSIONS

Our proposed technique of combined soft tissue procedures, including lateral soft tissue release, MPFL reconstruction (using a partial-thickness quadriceps tendon autograft), the Roux-Goldthwait procedure, and V-Y quadricepsplasty, was an effective method for treating patellar instability in children with DS while avoiding physeal injury and patellar fracture. Functional scores and radiological outcomes were improved.

LEVEL OF EVIDENCE

IV; retrospective case series.

Double-Bundle Quadriceps Tendon Autograft for Reconstruction of the Medial Patellofemoral Complex to Manage Recurrent Patellar Dislocation in Patients With Open Physes

Management of chronic patellar instability in patients with open physis requires special reconstruction techniques to minimize the risks of femoral growth plate injury due to the close proximity of the open physis to the native femoral origin of the medial patellofemoral ligament (MPFL). Children and adolescents have a relatively smaller patella than the adult group, so, there is a higher risk of patellar fracture when tunnels are performed in the patella. It is wise to mimic the normal anatomy of the medial patellofemoral complex (MPFC) by reconstruction of both of the medial quadriceps tendon femoral ligament (MQTFL) and MPFL, so as to restore the normal fan-shaped MPFC, with its wide anterior attachment to both of the patella and quadriceps tendon (QT). This article describes a simple, safe, reproducible, and cost effective technique for surgical management of chronic patellar instability in patients with open physis by reconstruction of the MPFC using a double-bundle QT autograft.

Editorial Commentary: The Medial Patellofemoral Ligament Is Not Isometric and Anatomic Reconstruction Is Important, But Just a Small Piece of the Patellar Instability Puzzle

Medial patellofemoral ligament (MPFL) reconstruction has proven to be a reliable procedure to reduce patellar instability events in patients with recurrent patellar instability. As our reconstruction techniques have evolved to address pathology in a diverse patient population, there continues to be an obsessive focus on the precise anatomy of the MPFL origin on the medial knee, due in large part to concerns that improper femoral tunnel position may result in excessive graft anisometry and failure. However, recurrent patellar instability involves many complexities and should not be simply reduced to a single point on the medial knee.