An interventional study of Medial Patellofemoral Ligament Reconstruction and Rehabilitation in Patellar (or Kneecap) Instability and Mal-alignment and Patellar Dislocation, sponsored by McMaster University. Withdrawn. Open to participants aged 10 Years to 25 Years. Per ClinicalTrials.gov, last updated 2026-10-07.
Sponsored by McMaster University · Not applicable, Interventional, and Treatment
No participants recruited
This study involves patients between the ages of 16 and 25 and have been diagnosed with a first-time traumatic patellar dislocation within the past 3 months. McMaster University and the investigators are receiving compensation from the Arthroscopy Association of North America to cover the costs of conducting the study.
Dislocations of the kneecap or patella is often treated without surgery, however up to 50% of patients will unfortunately experience recurrent instability of the patella. These episodes can cause damage to the bones and cartilage in the knee, which can result in long-term knee pain or weakness. Therefore, there is increasing interest to consider treating the knee with surgery right away in this population.
The purpose of this study is to determine the effect of medial patellofemoral ligament (MPFL) reconstruction compared to rest and physical rehabilitation on the rate of repeat patella dislocation, pain, and knee function for patients with their first patellar dislocation. The investigators will follow patients for at least one year after assigned treatment is started. Outcomes will be measured using surveys and checking medical records over the course of the study. The pilot will test this research study on a smaller scale before conducting a larger study. Patients will not be asked to attend additional visits outside of their typical follow-up schedule with their doctor.
There will be 30 patients recruited in total for this pilot study. Not all patients diagnosed with a patellar dislocation will be eligible to participate. Participation will be required at 6 regularly scheduled appointments that patients would need to attend to see the surgeon (even if they were not in the trial), including the screening visit, surgery date (if randomized to that treatment), 2-week, 6-week, 3-month, 6-month, and 12-month follow-up visits. Patients will be asked how they feel via various questionnaires and should take no longer than 15-20 minutes to complete the research forms at each visit.
If patients agree to participate in this study, treatment will be determined by a process called randomization. Randomization means that the treatment the patient receives will be decided by chance like flipping a coin. Patients will have a 1-in-2 chance of receiving one of the following treatments:
Patellar dislocation is a common orthopedic injury, with an overall incidence of acute first-time dislocation ranging between 2.3 and 23.2 per 100 000 person years, occurring often secondary to a non-contact flexion-rotation injury. The medial patellofemoral ligament (MPFL) is an hourglass shaped structure that originates on the superomedial aspect of the patella, and inserts onto the medial femoral epicondyle. This ligament is essential, as it serves as a primary checkrein to lateral patellar translation between 0-30 degrees of knee flexion. Surgical intervention often aims to replace this ligament to recreate this checkrein, in the form of MPFL reconstruction. Traditionally, patients who have sustained first-time patellar dislocations have been treated nonoperatively, and surgical intervention has mostly been reserved for patients with recurrent dislocations. However, the evidence behind this decision-making process is limited.
Specifically, a recently published a systematic review and meta-analysis comparing early MPFL reconstruction with rehabilitation, finding a pooled recurrent dislocation rate of 7% (95%CI 2-17%) in the reconstruction group compared to 30% (95%CI 25-36%) in the rehabilitation group. Another meta-analysis reported inferior rates of recurrent dislocation with rehabilitation (30%, 95%CI 25-36%) compared to acute MPFL repair (7%, 95%CI 3-12%). These findings were again found in the pediatric population, as reported by another meta-analysis published by our group, finding a pooled recurrent dislocation rate of 25.1% in the surgical group, compared with 46.4% in the conservative management group. When stratifying results by type of surgical procedure performed, the MPFL reconstruction group had a recurrent dislocation rate of 3.1% compared to that of other procedures, such as MPFL repair, lateral release, or medial imbrication, with a recurrent dislocation rate of 39.4%.
There have only been two prospective studies comparing MPFL reconstruction with rehabilitation for first-time dislocation. Based on the minimal number of adverse events, these studies demonstrated safety of early surgical intervention in first-time patellar dislocations, in addition to lower rates of recurrent patellar instability. However, allocation into treatment groups was not randomized in one study while the other study had a small sample size of only 39 patients which may bias and limit the applicability of the results.
This is a pilot randomized controlled trial (RCT) that will determine in patients under 25 years old with acute first-time patellar dislocations, the effect of early medial patellofemoral ligament (MPFL) reconstruction vs rehabilitation on recurrent dislocation rates, anterior knee pain, patient reported functional outcomes and complication rates at 12 months. The rationale for this trial is based on 1) the burden of patellar instability in the general population, 2) the high risk of progression to recurrent instability, 3) serious long-term, deleterious effects to the knee with recurrent instability, 4) the lack of definitive evidence or guidelines on the optimal treatment strategy in patients with these injuries, 5) promising results seen with early MPFL reconstruction in previous smaller studies, 6) lack of well-powered, high-quality, RCTs assessing early MPFL reconstruction after an acute first-time patellar dislocation patients. This trial is important and novel because it will provide surgeons with high-quality level I evidence to guide treatment decisions in patients with acute first-time patellar dislocations.
40 studies on the registry are indexed under Patella Fracture; 9 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
An initial evaluation with a diagnostic knee arthroscopy is done to ensure there are no loose bodies or osteochondral lesions missed on MRI that require removal or fixation. Graft harvest and preparation is done using either an autograft or allograft tendon as per a shared decision-making approach between the surgeon and patient. A 2cm longitudinal incision is made over the anteromedial aspect of the patella and dissection done between the second and third layers. Fixation (variable depending on surgeon preference) is performed over the proximal half of the patella. Another skin incision is then made over the medial femoral epicondyle with a guide pin passed through Schottle's point. The proximal femoral cortex is then drilled overtop of the guide pin to a diameter equal to the graft diameter with the remainder of the femoral tunnel drilled to 4.5mm.The graft ends are tied to the patellar fixation and shuttled through the second and third layers and fixed to the femur.
Procedure: Medial Patellofemoral Ligament Reconstruction
Patients will be initially placed in a patellar stabilizing brace and told to remain non weight-bearing for the first two weeks. Subjects will be permitted to perform gentle ROM exercises while in the knee brace with progressive weight-bearing as tolerated permitted at the 2-week mark. Formal physiotherapy commences at 2-weeks post-enrollment, with a goal of return to activities or sport at 6-months post-enrollment.
Other: Rehabilitation
An initial evaluation with a diagnostic knee arthroscopy is done to ensure there are no loose bodies or osteochondral lesions missed on MRI that require removal or fixation. Graft harvest and preparation is done using either an autograft or allograft tendon as per a shared decision-making approach between the surgeon and patient. A 2cm longitudinal incision is made over the anteromedial aspect of the patella and dissection done between the second and third layers. Fixation (variable depending on surgeon preference) is performed over the proximal half of the patella. Another skin incision is then made over the medial femoral epicondyle with a guide pin passed through Schottle's point. The proximal femoral cortex is then drilled overtop of the guide pin to a diameter equal to the graft diameter with the remainder of the femoral tunnel drilled to 4.5mm.The graft ends are tied to the patellar fixation and shuttled through the second and third layers and fixed to the femur.
Patients will be initially placed in a patellar stabilizing brace and told to remain non weight-bearing for the first two weeks. Subjects will be permitted to perform gentle ROM exercises while in the knee brace with progressive weight-bearing as tolerated permitted at the 2-week mark. Formal physiotherapy commences at 2-weeks post-enrollment, with a goal of return to activities or sport at 6-months post-enrollment.
Recurrent dislocation and instability
1. The rate of recurrent patellar dislocation at 12 months 2. The rate of recurrent subjective instability at 12 months 3. The rate of recurrent instability requiring surgical management at 12 months
Time frame: 12 months post- start of intervention
Visual Analogue Score (VAS)
The VAS is one of the most commonly used pain rating scores in both research and clinical practice, it is an easy-to-use, validated, one-dimensional scale from 0-10
Time frame: 12 months post- start of intervention
Kujala Anterior Knee Pain Scale
The Kujala Anterior Knee Pain scale is a 13-item screening instrument used to assess patellofemoral pain in adolescents and young adults, with a variable ordinal response format. Total scores range from 0-100.
Time frame: 12 months post- start of intervention
Banff Patellofemoral Instability Index 2.0 (BPII2.0)
The Banff Patellofemoral Instability Index 2.0 (BPII 2.0) Score is a metric of quality of life with multiple domains and subdomains having participants rate items from 0-100
Time frame: 12 months post- start of intervention
Tegner Activity Scale
The Tegner activity scale is a numerical scale with each value (0-10) representing specific activities An individual participating in competitive sports has an activity level of 10. An individual participating in recreational sports has an activity level of 6. An individual on sick leave or disability pension due to knee problems has an activity of 0
Time frame: 12 months post- start of intervention
Adverse Events
Occurrence of adverse events such as patellar fracture, patellar cartilage lesion or other events (other than recurrent patellar dislocations), obtaining a subsequent MRI to evaluate for pathology, and secondary chondral injury not present on an initial MRI if recurrent MRI is performed
Time frame: 12 months post- start of intervention
Recurrent Instability of the Patella score
Will also aim to validate the Recurrent Instability of the Patella score, this will help determine which patients may benefit from surgical intervention for first-time dislocation by classifying their risk of recurrent dislocation as either low, intermediate, or high based on preoperative factors. The Recurrent Instability of the Patella score consists of four factors: age \<25 years (worth 2 points), skeletal immaturity (worth 1 point), Dejour A-D dysplasia (worth 1 point), and TT-TG/patellar length \>= 0.5 (worth 1 point), for a maximum score of 5. Scores of 0-1 are deemed as low risk, 2-3 as intermediate risk, and 4-5 points as high risk.
Time frame: 12 months post- start of intervention
No study locations are listed for this record.
Plan to share: No — IPD will not be shared to avoid risks of compromising patient confidentiality.
No publications or documents are linked to this record.
No participants recruited
No participants recruited
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is withdrawn, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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