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

Not Applicable
Recruiting
Conditions
Patellar Instability
Interventions
Procedure: Dynamic reconstruction technique according to Becher
Procedure: Static reconstruction technique according to Schöttle
Registration Number
NCT04849130
Lead Sponsor
University Hospital, Basel, Switzerland
Brief Summary

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

Detailed Description

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.

Recruitment & Eligibility

Status
RECRUITING
Sex
All
Target Recruitment
60
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

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Dynamic reconstruction technique according to BecherDynamic reconstruction technique according to BecherDynamic reconstruction technique according to Becher
Static reconstruction technique according to SchöttleStatic reconstruction technique according to SchöttleStatic reconstruction technique according to Schöttle
Primary Outcome Measures
NameTimeMethod
Change in Kujala scoreup to 24 months

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.

Secondary Outcome Measures
NameTimeMethod
Number of revision surgeryFrom MPFL surgery to occurring revision surgery (up to 24 months)

Surgical outcome: revision surgery.

Change in EQ-5D-5L from preoperative screening, at the hospitalization time and four postoperative follow ups EQ-5D- EQ-5D-5Lup to 24 months

The EQ-5D descriptive system comprises five dimensions: mobility, self-care, usual activities, pain and discomfort, and anxiety and depression. The five levels in each dimension are worded as (1) 'not /no problems', (2) 'slight problems', (3) 'moderate problems', (4) 'severe problems', and (5) 'unable to' (mobility, self-care, usual activities), 'extreme' (pain/depression), or 'extremely' (anxiety/depression).

Hospitalization timeDuring hospitalization (up to 1 month)

Length of hospital stay Length of hospital stay

Change in gait asymmetryPreoperatively and 1 year postoperative

Instrumented gait analysis (by EMG) on a treadmill with an embedded plantar pressure plate and on an overground walkway with two embedded force plates.

Number of recurrent patella dislocationFrom MPFL surgery to occurring recurrent patella dislocation (up to 24 months)

Surgical outcome: recurrent patella dislocation.

Number of complications (other than revision surgery, e.g. infection, wound healing disorder)From MPFL surgery to occurring complication (up to 24 months)

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

Change in Banff-II-score from preoperative screening, at the hospitalization time and four postoperative follow upsup to 24 months

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.

Operation timeDuring MPFL surgery (up to 1 day)

Operation time

Change in isokinetic muscle strengthPreoperatively and 1 year postoperative

Muscle strength will be measured bilaterally using a dynamometer.

Change in timing of muscle activityPreoperatively and 1 year postoperative

Timing of the gracilis muscle will be assessed as on- and offset relative to the gait cycle. Gracilis onset will be determined as the time when the processed EMG signal exceeded a threshold of three standard deviations above a baseline mean and as offset, when the processed EMG signal falls below a threshold of three standard deviations above a baseline mean.

Change in single legged drop testPreoperatively and 1 year postoperative

Standing erect upon only the tested leg with the foot in neutral position, participants will step off a 30 cm high platform placed 11 cm from the edge of the force-plate. Participants will be instructed to land in the centre of the force-plate on the tested leg only.

Change in International Knee Documentation Committee (IKDC)-2000 from preoperative screening, at the hospitalization time and four postoperative follow upsup to 24 months

The IKDC includes 18 questions covering three domains: symptoms, physical activity, and function. The items are answered on Likert scales of varying values. IKDC scores are calculated by dividing the total score by the highest possible score for the items answered, and multiplying by 100, with higher scores indicating better function.

Change in pain level using the numeric rating scale from preoperative screening, at the hospitalization time and four postoperative follow upsup to 24 months

It is usually presented as a 100-mm horizontal line on which the patient's pain intensity is represented by a point between the extremes of "no pain at all" and "worst pain imaginable."

Trial Locations

Locations (2)

Department of Orthopaedics and Traumatology, University Hospital Basel

🇨🇭

Basel, Switzerland

Department of Orthopaedics and Traumatology, Swiss Altius Medical Clinic

🇨🇭

Rheinfelden, Switzerland

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