Comparison of Dynamic and Static Medial Patellofemoral Ligament Operation Technique for Recurrent Patellar Dislocation

University Hospital, Basel, Switzerland60 enrolled

Overview

This study is to evaluate whether the dynamic Medial Patellofemoral Ligament (MPFL) reconstruction as described by Becher is a successful operation technique to prevent patella instability and restore quality of life. It is to assess and compare clinical and functional outcomes of dynamic and static medial patellofemoral ligament reconstruction

The recurrent dislocation rate of conservatively treated chronic patellar instability is high, therefore, it is recommended to manage it surgically. A frequently used surgical technique is static medial patellofemoral ligament (MPFL) reconstruction (e.g. Schöttle-technique). A novel dynamic surgical technique according to Becher was developed, addressing the most common complications occurring in static reconstruction, which are malpositioning and overtensioning of the graft. This study is to assess and compare clinical and functional outcomes of dynamic and static medial patellofemoral ligament reconstruction.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Enrollment

Conditions

Patellar Instability

Interventions

Static reconstruction technique according to SchöttlePROCEDURE

In static MPFL reconstruction, a graft (harvested autologous gracilis tendon or allogen transplant) is attached to the femoral and patellar bones using tunnels, screws, and/or anchors.

Dynamic reconstruction technique according to BecherPROCEDURE

Dynamic MPFL procedure by detaching and reinserting only the distal part of a hamstring muscle to the patella and leaving the proximal tendon attached to its muscle. This way the patella position can be adjusted dynamically by hamstring contraction.

Eligibility

Sex: ALLMin age: 14 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Patients treated with isolated dynamic (operation procedure according to Becher et al.using the gracilis tendon) or static MPFL plastic (operation procedure according to Schöttle et al. using the gracilis tendon). MPFL reconstruction will be performed in patients with preceding patella dislocation with: 1) a Patella-Instability-Severity (PIS) score ≤ 3 with concomitant flake fracture or 2) a PIS score ≥ 4 with clinical asymptomatic trochlea dysplasia (patella stability between 30°-60° knee flexion) without other clinically relevant static risk factors. * Closed growth plates Exclusion Criteria: * Combined procedures with trochleoplasty (high grade trochlea dysplasia, type Dejour C,D with clinical instability between 30° and 60° of knee flexion) * combined procedures with cartilage transplantation * High grade patellofemoral arthritis (Kellgren Lawrence score ≥3) * combined procedures with femoral or tibial osteotomy * Clinically eminent valgus axis (\>15° valgus) * Femoral internal rotation \>20°, tibial external rotation \>40° * Instability of the cruciate or collateral ligaments * Known significant musculoskeletal disease * Cognitive impairment

Locations (2)

Department of Orthopaedics and Traumatology, University Hospital Basel

Basel, Switzerland

RECRUITING

Department of Orthopaedics and Traumatology, Swiss Altius Medical Clinic

Rheinfelden, Switzerland

RECRUITING

Outcomes

Primary Outcomes

Change in Kujala score

Patient reported knee function and anterior knee pain as assessed with the Kujala score at preoperative screening, at the hospitalization time and four postoperative follow ups . The Kujala scale consists of 13 questions covering a range of physical symptoms and limitations that are presented in a multiple choice answer format, with a different point value assigned to each answer. The maximum score is 100, with higher scores indicating better function.

Time frame: up to 24 months

Secondary Outcomes

Number of recurrent patella dislocation

Surgical outcome: recurrent patella dislocation.

Time frame: From MPFL surgery to occurring recurrent patella dislocation (up to 24 months)

Number of revision surgery

Surgical outcome: revision surgery.

Time frame: From MPFL surgery to occurring revision surgery (up to 24 months)

Number of complications (other than revision surgery, e.g. infection, wound healing disorder)

Surgical outcome: complications (other than revision surgery, e.g. infection, wound healing disorder).

Time frame: From MPFL surgery to occurring complication (up to 24 months)

Change in Banff-II-score from preoperative screening, at the hospitalization time and four postoperative follow ups

The Banff Patella Instability Instrument (BPII) is a disease-specific health-related quality of life score. It is a patient-reported, disease-specific QOL score that consists of 23 questions across five domains covering symptoms/physical complains, work-related concerns, recreational activity and sport participation/competition, lifestyle, and social/emotional. Patients mark their answers on a visual analogue scale measuring 100 mm in length. Each item is equally weighted with the final score calculated as an average of the scores from all answered items. A higher score reflects a higher QOL.

Central Contacts

Christian Egloff, PD Dr. med.

CONTACT

+41 79 75 33 72 4 christian.egloff@usb.ch

Daniel Rikli, Prof. Dr. med.

CONTACT

+41 79 75 33 72 4 daniel.rikli@usb.ch

Data from ClinicalTrials.gov

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