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Radiologie (Heidelberg, Germany) Apr 2024Patellofemoral instability (PFI) describes a (sub)luxation of the patella in the patellofemoral joint. Pathophysiologically, PFI is usually due to a nonphysiological... (Review)
Review
Patellofemoral instability (PFI) describes a (sub)luxation of the patella in the patellofemoral joint. Pathophysiologically, PFI is usually due to a nonphysiological movement of the patella, so-called maltracking, either due to acute trauma with injury to the supporting ligamentous apparatus or due to the presence of anatomical risk factors. Radiologically assessable risk factors for maltracking include trochlear dysplasia, patella alta, patellar tilt, lateralization of the tibial tuberosity, torsional deformity and genu valgum. This article presents the most commonly used and best validated measurement techniques. In addition, the characteristic injury pattern after lateral patellar dislocation is shown.
Topics: Animals; Patellar Dislocation; Joint Instability; Patellofemoral Joint; Joint Dislocations; Patella; Gastropoda
PubMed: 38483571
DOI: 10.1007/s00117-024-01284-2 -
Trials Jan 2022Patellar instability is a common and understudied condition that disproportionally affects athletes and military personnel. The rate of post-traumatic osteoarthritis... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Patellar instability is a common and understudied condition that disproportionally affects athletes and military personnel. The rate of post-traumatic osteoarthritis that develops following a patellar dislocation can be up to 50% of individuals 5-15 years after injury. Conservative treatment is the standard of care for patellar instability however, there are no evidence-informed rehabilitation guidelines in the scientific literature. The purpose of this study is to assess the effectiveness of blood-flow restriction training (BFRT) for patellar instability. Our hypotheses are that this strategy will improve patient-reported outcomes and accelerate restoration of symmetric strength and knee biomechanics necessary to safely return to activity.
METHODS/DESIGN
This is a parallel-group, superiority, randomized, double-blinded, placebo-controlled clinical trial at the University of Kentucky, sports medicine clinic that aims to recruit 78 patients with acute patellar dislocations randomly allocated into two groups: (1) sham BFRT and (2) BFRT. Both groups will receive the current standard of care physical therapy 3 times per week for up to 9 weeks. Physical therapy sessions will consist of typical standard of care treatment followed by BFRT or sham BFRT. Primary outcomes include the Norwich Patellar Instability Scale, quadriceps strength, and imaging and biochemical biomarkers of cartilage degradation.
DISCUSSION
The current standard of care for non-operative treatment of patellar instability is highly variable does not adequately address the mechanisms necessary to restore lower extremity function and protect the long-term health of articular cartilage following injury. This proposed novel intervention strategy uses an easily implementable therapy to evaluate if BFRT significantly improves patient-reported outcomes, function, and joint health over the first year of recovery.
TRIAL REGISTRATION
Blood Flow Restriction Training, Aspiration, and Intraarticular Normal Saline (BRAINS) NCT04554212 . Registered on 18 September 2020.
Topics: Blood Flow Restriction Therapy; Humans; Joint Instability; Patellar Dislocation; Patellofemoral Joint; Saline Solution
PubMed: 35090543
DOI: 10.1186/s13063-022-06017-1 -
Arthroscopy : the Journal of... Nov 2023The work-up of patellofemoral instability is complex and multifactorial. Patient factors (i.e., age, activity demand, goals/expectations), clinical presentation (pain,...
The work-up of patellofemoral instability is complex and multifactorial. Patient factors (i.e., age, activity demand, goals/expectations), clinical presentation (pain, instability, or both), and physical examination (i.e., J-sign, apprehension into flexion), must be correlated with imaging findings (radiographs, magnetic resonance imaging, computed tomography) and anatomic risk factors, including patella alta, trochlear dysplasia, patellar tilt, lateralized force vector, valgus, femoral anteversion, and tibial torsion. Thus, developing a standard battery of reliable and reproducible radiographic measures of patellofemoral instability is a challenge. Imaging cut-offs provide insight into relative risk of recurrent instability. We still fall short in using imaging parameters to predict when to operate, what procedure(s) to perform, and how the patient might do. Future directions include the use of artificial intelligence and 3-dimensional measurements to help simplify a complex problem.
Topics: Humans; Patellofemoral Joint; Tibia; Artificial Intelligence; Retrospective Studies; Joint Instability; Patella; Patellar Dislocation
PubMed: 37866875
DOI: 10.1016/j.arthro.2023.05.026 -
The Journal of Knee Surgery Oct 2020Acute traumatic patellar dislocation is a common injury, and spontaneous reduction may occur at the time of injury or may be reduced at the field of the accident by...
Acute traumatic patellar dislocation is a common injury, and spontaneous reduction may occur at the time of injury or may be reduced at the field of the accident by someone. It may be associated with osteochondral fractures and rupture of medial patellar stabilizers leading to recurrent patellar instability. The aim of this prospective study was to evaluate the outcomes of medial patellofemoral (PF) ligament (MPFL) reconstruction in recurrent traumatic patellar dislocation. Forty-five patients presented with PF instability as a result of traumatic rupture MPFL with normal patellar tracking underwent MPFL reconstruction without patellar fixation hardware through two parallel transpatellar tunnels and one screw in femoral tunnel. All patients were evaluated clinically preoperatively and at a minimum follow-up of 24 months, and International Knee Documentation Committee (IKDC) and Kujala scores were used to assess the clinical results. All patients were available for evaluation at a minimum of 24 months (up to 36 months). The mean age of these patients at the time of surgery was 22.82 years (range: 18-34 years). All patients gave history of trauma of their knees. Mean IKDC scale showed significant improvement as it rose from 47.17 preoperatively to 77.94 postoperatively, and mean Kujala score rose from 53.88 preoperatively to 86.24 postoperatively ( < 0.001). No recurrence of dislocation was recorded. Only three patients had mild atrophy of thigh and one patient had some difficulty in jumping. Reconstruction of MPFL by this method provides good clinical result in the treatment of PF instability by using autologous graft (semitendinosus and gracilis). Less hardware were used with less complications.
Topics: Adolescent; Adult; Female; Follow-Up Studies; Humans; Joint Instability; Ligaments, Articular; Male; Patellar Dislocation; Patellofemoral Joint; Prospective Studies; Recurrence; Tendons; Transplantation, Autologous; Young Adult
PubMed: 31121630
DOI: 10.1055/s-0039-1688841 -
The Surgeon : Journal of the Royal... Aug 2022Evidence concerning the influence gender, age, and the time elapsed from the first dislocation to surgery in the outcomes of Medial Patella Femoral Ligament (MPFL)... (Review)
Review
BACKGROUND
Evidence concerning the influence gender, age, and the time elapsed from the first dislocation to surgery in the outcomes of Medial Patella Femoral Ligament (MPFL) reconstruction are lacking. This systematic review was conducted to investigate whether patient characteristics have an influence in the clinical outcomes of MPFL reconstruction for patients with patellofemoral instability.
MATERIAL AND METHODS
This study followed the PRISMA guidelines. The main databases were accessed in February 2021. All the studies reporting outcomes of primary MPFL reconstruction in patients with recurrent patellofemoral instability were considered for inclusion. A multivariate analysis diagnostic tool was used to analyse the association between age, gender and time from injury to surgery and the surgical outcomes at last follow-up.
RESULTS
A total of 50 articles (2037 procedures) were included. The mean follow-up was 40.90 ± 24.8 months. The mean age was 23.6 ± 3.9 years. 64.3% (1309 of 2037 patients) were female. The mean time from injury to surgery was 64.5 ± 48.9 months. Women showed no statistically significant association with the Kujala score or complications. Older patients had a reduced risk to incur re-dislocations (P = 0.01) and revisions (P = 0.01). Longer time from injury to surgery was associated with greater risk to incur re-dislocations (P = 0.01), and with lower Kujala score (P < 0.0001). No other statistically significant association was evidenced.
CONCLUSION
The time span from the first patellar dislocation to the surgical reconstruction was a negative prognostic factor, while sex had no influence on surgical outcomes. The role of patients age on surgical outcomes remains unclear.
Topics: Adult; Female; Humans; Joint Dislocations; Joint Instability; Ligaments, Articular; Male; Patellar Dislocation; Patellofemoral Joint; Prognosis; Young Adult
PubMed: 33962891
DOI: 10.1016/j.surge.2021.03.003 -
Arthroscopy : the Journal of... Apr 2024To compare clinical and radiographic outcomes of medial patellofemoral ligament reconstruction (MPFL-R) and medial patellofemoral complex reconstruction (MPFC-R) for...
Medial Patellofemoral Complex Reconstruction (Combined Reconstruction of Medial Patellofemoral Ligament and Medial Quadriceps Tendon-Femoral Ligament) With Semitendinosus Autograft Resulted in Similar Clinical and Radiographic Outcomes to Medial Patellofemoral Ligament Reconstruction in Treating...
PURPOSE
To compare clinical and radiographic outcomes of medial patellofemoral ligament reconstruction (MPFL-R) and medial patellofemoral complex reconstruction (MPFC-R) for recurrent patellar dislocation. Outcome measures were compared based on the Insall-Salvati index.
METHODS
Patients who were diagnosed with recurrent patellar dislocation and underwent either MPFL-R or MPFC-R (combined reconstruction of MPFL and medial quadriceps tendon-femoral ligament) were retrospectively analyzed. Group allocation was based on surgical procedure and patient characteristics were collected. Clinical assessments included patient-reported outcome measures (PROMs) and return-to-sports rates. Minimal clinically important difference analysis was performed. A subgroup analysis of PROMs was carried out between patients with an Insall-Salvati index ≤1.2 versus >1.2. The patellar tilt angle, lateral patellar displacement, and bisect offset ratio were measured pre- and postsurgery. Functional failures and complications were assessed.
RESULTS
Overall, 70 patients (72 knees) in the MPFL-R group and 58 patients (61 knees) in the MPFC-R group were included. Patient characteristics were comparable between the groups. At a minimum follow-up of 24 (mean, 50.6 ± 22.1) months, all PROMs were substantially improved (P < .001), without significant intergroup differences. The percentages of patients reaching the minimal clinically important difference were similar after MPFL-R and MPFC-R: 98.6% versus 93.4% (International Knee Documentation Committee), 97.2% versus 98.4% (Lysholm), 98.6% versus 100% (Kujala), and 77.8% versus 72.1% (Tegner). The subgroup analysis based on patellar height and the return-to-sport rates also suggested comparable results. Radiographic evaluation demonstrated significantly smaller lateral patellar displacements (P = .004) and bisect offset ratios (P < .001) but similar patellar tilt angles after MPFC-R. Four (5.6%) patients receiving MPFL-R and 2 (3.3%) patients receiving MPFC-R reported recurrence of functional instability, without statistically significant difference.
CONCLUSIONS
MPFC-R resulted in similar overall clinical and radiographic outcomes to MPFL-R in treating recurrent patellar dislocation. MPFC-R might not provide additional benefits for patients with an Insall-Salvati index >1.2.
LEVEL OF EVIDENCE
Level IV, therapeutic, retrospective cohort study.
Topics: Humans; Patellar Dislocation; Retrospective Studies; Patellofemoral Joint; Hamstring Muscles; Autografts; Tibia; Joint Dislocations; Ligaments, Articular; Tendons; Patella; Joint Instability
PubMed: 37716628
DOI: 10.1016/j.arthro.2023.08.079 -
Knee Surgery, Sports Traumatology,... Jun 2021In this study, the functional mid-term outcomes of the modified Grammont and Langenskiöld technique was assessed in skeletally immature patients with habitual patellar...
PURPOSE
In this study, the functional mid-term outcomes of the modified Grammont and Langenskiöld technique was assessed in skeletally immature patients with habitual patellar dislocation, with emphasis on knee function, pain, and other possible post-surgical complications. This is the first study concerning the application of the modified Grammont and Langenskiöld technique in habitual patellar dislocations.
METHODS
This retrospective cohort study considered 10 patients (15 knees), ranging from 7 to 11 years old, who underwent the modified Grammont and Langenskiold procedure between 2015 and 2018. History of dislocation, patellar stability and range of motion (ROM) were analysed. To assess functional improvement and knee pain, the Kujala Anterior Knee Pain Scale and KOOS-Child Knee Survey were used before and after surgical treatment.
RESULTS
No history of dislocation was noted after surgical treatment. All 15 knees showed full ROM. There were no signs of genu recurvatum and no length discrepancies were found. The subjective assessment revealed significant improvement in the scores of the KOOS-Child questionnaire in all five sections (p < 0.001), as well as in The Kujala Anterior Knee Pain Scale (p = 0.001).
CONCLUSION
The modified Grammont and Langenskiöld technique yields remarkable results in terms of knee stability and knee function, while decreasing recurrence risk and intensity of pain in patients with challenging cases of patellofemoral joint dislocation. This surgical technique is most effective in cases where the patella remains dislocated continuously; however, it may also be used in immature patients with recurrent instability.
LEVEL OF EVIDENCE
IV.
Topics: Arthralgia; Arthroplasty; Child; Female; Humans; Male; Patellar Dislocation; Patellofemoral Joint; Range of Motion, Articular; Recurrence; Retrospective Studies; Treatment Outcome
PubMed: 32980886
DOI: 10.1007/s00167-020-06284-y -
Journal of ISAKOS : Joint Disorders &... Dec 2023To assess the inter- and intra-rater reliability of the classification of the J-sign as "large" versus "small or none" as compared to another two-level system ("present"...
OBJECTIVES
To assess the inter- and intra-rater reliability of the classification of the J-sign as "large" versus "small or none" as compared to another two-level system ("present" versus "absent") and a three-level system ("large," "small," or "none") and to identify anatomical and patient factors associated with the presence of a large J-sign.
METHODS
Forty patients (40 knees) with recurrent patellar instability were prospectively enrolled and recorded on video actively extending their knee while seating. Four raters classified patellar tracking on two separate occasions using three systems: 1) two groups: J-sign versus no J-sign; 2) three groups: large J-sign, small J-sign, or no J-sign; and 3) two groups: large J-sign versus small or no J-sign. The intra- and inter-rater reliability of each system was assessed using kappa statistics. Anatomical (trochlear dysplasia, tibial tubercle-trochlear groove (TT-TG) distance, patellar height) and patient (Beighton score) factors as well as Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales were compared between patients with a large J-sign and patients with a small or no J-sign.
RESULTS
Inter- and intra-rater reliability were found to be highest with the two-level classification system of a large J-sign versus a small or no J-sign (inter-rater kappa = 0.76, intra-rater kappa = 0.75). Patients with a large J-sign had more severe trochlear dysplasia as assessed with the sulcus angle (p = 0.042) and were more likely to have a tight lateral retinaculum (p = 0.032) and an elevated Beighton score (p = 0.009). No significant differences in KOOS subscales were noted based on the presence of a large J-sign versus a small J-sign or no J-sign.
CONCLUSION
Qualitative visual assessment of patellar tracking with the J-sign demonstrates substantial inter- and intra-rater reliability, particularly when utilizing a two-group classification system to identify knees with a large J-sign. Patients with a large J-sign demonstrate an increased incidence of a tight lateral retinaculum, generalized ligamentous laxity, and trochlear dysplasia.
LEVEL OF EVIDENCE
Level III - cross-sectional study.
Topics: Humans; Patellar Dislocation; Patellofemoral Joint; Joint Instability; Reproducibility of Results; Cross-Sectional Studies
PubMed: 37499874
DOI: 10.1016/j.jisako.2023.07.006 -
Archives of Orthopaedic and Trauma... Jul 2023Impaired hip kinematics and kinetics may incite patellar instability. This study tested the hypothesis that hip adduction and internal rotation angles during gait are...
INTRODUCTION
Impaired hip kinematics and kinetics may incite patellar instability. This study tested the hypothesis that hip adduction and internal rotation angles during gait are higher in adolescents with recurrent patellar dislocations compared to healthy controls.
MATERIAL AND METHODS
Case-control study. Eighty-eight knees (67 patients) with recurrent patellar dislocation (mean age 14.8 years ± 2.8 SD) were compared to 54 healthy knees (27 individuals, 14.9 years ± 2.4 SD). Peak hip, knee and pelvis kinematics and kinetics were captured using 3D-gait analysis (VICON, 12 cameras, 200 Hz, Plug-in-Gait, two force plates) and compared between the two groups. One cycle (100%) consisted of 51 data points. The mean of six trials was computed.
RESULTS
Peak hip adduction angles and abduction moments were significantly higher in patients with recurrent patellar dislocation compared to the control group (p < 0.001 and 0.002, respectively). Peak internal hip rotation did not differ significantly.
CONCLUSION
Elevated hip adduction angles and higher hip abduction moments in gait of adolescents with recurrent patellar dislocation may indicate an impaired function of hip abductors that contributes to patellar instability.
Topics: Humans; Adolescent; Patellar Dislocation; Joint Instability; Case-Control Studies; Patellofemoral Joint; Gait; Knee Joint; Biomechanical Phenomena
PubMed: 36435929
DOI: 10.1007/s00402-022-04703-y -
Knee Surgery, Sports Traumatology,... Jan 2023To compare the values and the relationship of tibial tubercle lateralization measurements between computerized tomography (CT) and magnetic resonance imaging (MRI).
PURPOSE
To compare the values and the relationship of tibial tubercle lateralization measurements between computerized tomography (CT) and magnetic resonance imaging (MRI).
METHODS
Sixty patients with patellar dislocation who underwent both CT and MRI of the same knee joint from November 2021 to February 2022 were included in our study. The intraclass correlation coefficient (ICC) and Bland-Altman analysis were performed to evaluate the reliability of tibial tubercle-trochlear groove (TT-TG), tibial tubercle-Roman arch (TT-RA), and tibial tubercle-posterior cruciate ligament (TT-PCL) distance measurements. The values of CT and MRI measurements using the same bony landmarks were compared for the difference. Pearson correlation analysis and linear regression analysis were performed to assess the correlation between CT and MRI measurements. Finally, the estimated values obtained from the regression equation were compared with the actual values obtained from the radiological measurement to evaluate the accuracy of the equations.
RESULTS
A total of 60 patients with patellar dislocation who underwent both CT and MRI of the same knee joint were included in this study. The included measurements showed excellent agreement with ICCs > 0.9. TT-TG distance measured on CT (19.5 ± 5.1 mm) had a mean of 7.1 mm higher than that on MRI (12.4 ± 4.7 mm) (P < 0.001). The mean value of TT-RA distance was 22.5 ± 3.7 mm on CT and 16.7 ± 4.9 mm on MRI (P < 0.001), showing a mean difference of 5.8 mm. The values of TT-TG distance measured by CT and MRI were significantly correlated (R = 0.5, P < 0.001). The values of TT-RA distance between these two modalities showed a better correlation than that of TT-TG distance (R = 0.6, P < 0.001). The interchange values of TT-TG distance and TT-RA distance between CT and MRI can be obtained using regression equations (TT-TG distance: y = 0.6x + 12.3; TT-RA distance: y = 0.5x + 14.4).
CONCLUSION
The values of tibial tubercle lateralization measured by MRI may be underestimated compared with those measured by CT. Although the values measured on CT and MRI are not equivalent, the value in the other modality can be estimated. Therefore, an additional CT scan for tibial tubercle lateralization evaluation may not be necessary.
LEVEL OF EVIDENCE
Level II.
Topics: Humans; Patellar Dislocation; Patellofemoral Joint; Reproducibility of Results; Tibia; Magnetic Resonance Imaging; Tomography, X-Ray Computed; Joint Instability
PubMed: 36088618
DOI: 10.1007/s00167-022-07119-8