An observational study in Adductor Tendinitis, sponsored by Aspetar. Completed at 1 site in France. Open to male participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-03-03.
Sponsored by Aspetar · Observational
The bent knee fall out test (BKFO) is a common test for hip adductor flexibility. It is unknown whether the BKFO actually tests the the adductors or potentially hip range of motion instead.
In this study, the BKFO test is performed in the operating theater before and after an adductor longus tenotomy.
Adductor-related groin pain is the most common type of groin pain in athletes, and pain at the proximal adductor longus insertion is a key finding in the diagnosis of longstanding groin pain. "Tightness" or "shortening" of the adductor longus is considered both a cause and effect of pain, that can lead to increased tension at the proximal insertion, thus playing a role in the persistence of longstanding adductor-related pain. For patients who do not respond sufficiently to non-surgical procedures, an adductor longus tenotomy is a surgical option that is considered to reduce tension at the proximal adductor longus insertion assisting in reduction of pain and return to sport.
The bent knee fall out test (BKFO) is one of the most commonly used tests to test adductor flexibility. This test involves a combined hip movement with hip flexion, abduction, and external rotation, and a high result is generally considered to be related to adductor muscle "tightness", specifically that of the adductor longus. It is uncertain whether the BKFO test is actually measuring adductor muscle flexibility or hip joint range of motion, as the test results may also be affected by a femoral head cam morphology. A slightly different test, called the Patrick FABER's test, involves a similar movement and is mainly used as a hip joint pain provocation test.
By cutting the adductor longus tendon, thereby removing the effect of potential adductor longus "tightness", it will be possible to show if and how much the flexibility of this muscle affects the BKFO test results. This will assist in future considerations of what this test is actually testing.
The aim of this study is to investigate the immediate effect of an adductor longus tenotomy on the results of the bent knee fall out test.
397 studies on the registry are indexed under Tendinopathy; 77 are open to participants now.
This study's enrollment of 60 is close to the median of 61 across 50 observational studies indexed under Tendinopathy.
Browse Tendinopathy studies →Aspetar is the lead sponsor of 11 studies on the registry; 2 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Athletes with groin pain are consecutively recruited from two clinics of a visceral surgeon specialized in groin pain in athletes. The clinics are located in Bordeaux and Paris, France, and patient population includes athletes from all over France.
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:
The intervention included in this study is part of routine medical care, and not assigned as a result of study participation. This study includes only the addition of a measurement; the bent knee fall out test. Therefore, we believe this study design is observational, and in line with the provided observation study design definition: "Observational: studies in human beings in which biomedical and/or health outcomes are assessed in predefined groups of individuals. Participants in the study may receive diagnostic, therapeutic, or other interventions, but the investigator does not assign specific interventions to the study participants. This includes when participants receive interventions as part of routine medical care, and a researcher studies the effect of the intervention." See uploaded study protocol for further details.
Change in the Bent Knee Fall Out Test
The patient lies supine on the surgical table with app. 90° knee flexion, 45° hip flexion, and the feet together and the hips in external rotation (also known as the frog-leg position. Standardization of position is achieved by flexing one leg first, so the medial malleolus is placed next to the medial knee joint line of the contra-lateral leg. The knee is then moved laterally, externally rotating the hip with the plantar surface placed towards the contra-lateral leg. The contra-lateral leg is then flexed, and the plantar surfaces of the feet are aligned. The distance between the most distal point on the head of the fibula and the surface of the surgical table is measured using a rigid tape measure and distance is recorded in cm to the nearest 0.5 cm
Time frame: Baseline pre-surgery and immediately after the surgery.
| Milestone | Tenotomy |
|---|---|
| Started | 60 |
| Completed | 60 |
| Not completed | 0 |
The patient lies supine on the surgical table with app. 90° knee flexion, 45° hip flexion, and the feet together and the hips in external rotation (also known as the frog-leg position. Standardization of position is achieved by flexing one leg first, so the medial malleolus is placed next to the medial knee joint line of the contra-lateral leg. The knee is then moved laterally, externally rotating the hip with the plantar surface placed towards the contra-lateral leg. The contra-lateral leg is then flexed, and the plantar surfaces of the feet are aligned. The distance between the most distal point on the head of the fibula and the surface of the surgical table is measured using a rigid tape measure and distance is recorded in cm to the nearest 0.5 cm
| cm | Tenotomy |
|---|---|
| Change in the Bent Knee Fall Out Test | 3.9 ± 2 |
Collected over 1 year. Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Tenotomy | 0/60 (0%) | 0/60 (0%) | 0/60 (0%) |
| Age, Continuous(years) | Demographic Data of All Athletes |
|---|---|
| Median | 27 (23 to 34.5) |
| Sex: Female, Male(Participants) | Demographic Data of All Athletes |
|---|---|
| Female | 0 |
| Male | 60 |
| Race and Ethnicity Not Collected(Participants) | Demographic Data of All Athletes |
|---|
| Height(cm) | Demographic Data of All Athletes |
|---|---|
| Mean | 180.4 ± 7.8 |
| Weight(Kg) | Demographic Data of All Athletes |
|---|---|
| Median | 78 (71.5 to 85) |
| BMI(kg/m2) | Demographic Data of All Athletes |
|---|---|
| Median | 23.8 (22.2 to 26.2) |
PDFs hosted by the registry, ClinicalTrials.gov.
Plan to share: Undecided — There are currently no IPD plans. IPD data be obtained upon reasonable request
Ran from Nov 2019 to primary completion in May 2020, 6 months.
Results were first posted in Mar 2025, 4 years 9 months after primary completion.
Of 19 observational studies under Tendinopathy, half reached primary completion within 19 months of starting (the median), counting those still running; a quarter within 9 and three quarters within 36. This study's 6 months is below that.
How these figures are worked out, and which studies are left out of them.
This study is completed, as verified in Feb 2025. You cannot join it, but the record below documents what was studied.
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