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The American Journal of Sports Medicine May 2021Optimal treatment of patients with patellofemoral trochlear dysplasia and recurrent patellar instability requires in-depth understanding of this complex structural...
Optimal treatment of patients with patellofemoral trochlear dysplasia and recurrent patellar instability requires in-depth understanding of this complex structural anomaly. An extensive review of the literature suggests that dysplasia occurs as a result of aberrant forces applied to the patellofemoral joint in the majority of cases. Evidence supports surgical stabilization that reconstructs the medial patellofemoral and/or medial quadriceps tendon-femoral ligament without added trochleoplasty in the majority of patients with trochlear dysplasia and recurrent patellar instability. Adding tibial tubercle transfer distally, medially, or anteromedially in those who need it to treat specific deficits in alignment or articular cartilage can be beneficial in selected patients with trochlear dysplasia and recurrent patellar instability. Trochleoplasty may be appropriate in those few cases in which permanent stable patellofemoral tracking cannot be restored otherwise, but the indications are not yet clear, particularly as trochleoplasty adds risk to the articular cartilage. Improved understanding of imaging techniques and 3-dimensional reproductions of dysplastic patellofemoral joints are useful in surgical planning for patients with recurrent patellar instability and trochlear dysplasia.
Topics: Femur; Humans; Joint Instability; Patellar Dislocation; Patellofemoral Joint; Tendons
PubMed: 33021814
DOI: 10.1177/0363546520958423 -
Knee Surgery, Sports Traumatology,... Oct 2022Patellar instability is a frequent clinical situation in adolescents and young adults. One of the most important risk factors of this condition is trochlea dysplasia....
PURPOSE
Patellar instability is a frequent clinical situation in adolescents and young adults. One of the most important risk factors of this condition is trochlea dysplasia. Few studies have analyzed the role of patellar dysplasia. The objective of this paper was to assess the correlation between trochlear and patellar dysplasia. The hypothesis is that patellar dysplasia increased in parallel with femoral trochlear dysplasia.
METHODS
The study included patients operated on at least one knee for patellar instability between 2008 and 2020. For these patients, symptomatic knees (operated or not) were included if they had lateral and patellofemoral skyline radiographs. Two blinded observers categorized each trochlear and patellar dysplasia according to the Dejour and Wiberg classifications. Patellar height was also measured by applying the Caton-Deschamps index.
RESULTS
A total of 100 patients were selected, involving 149 symptomatic knees. A significant correlation between trochlear and patellar dysplasia types was found (0.82; p < 0.0001). Dejour types B and C of trochlear dysplasia were significantly more often associated with patellar dysplasia than Dejour type A (p = 0.033 and p = 0.019, respectively). Moreover, severe Wiberg 3 patellar dysplasia was significantly associated with type D Dejour trochlear dysplasia than with the sum of all other Dejour types taken together (p < 0.0001).
CONCLUSION
This study confirms a linear correlation between the severity of patellar and trochlear dysplasia. Further studies are needed to evaluate the place of patellar dysplasia in the therapeutic strategy.
LEVEL OF EVIDENCE
Level IV.
Topics: Adolescent; Humans; Joint Instability; Knee Joint; Patella; Patellar Dislocation; Patellofemoral Joint; Young Adult
PubMed: 35347377
DOI: 10.1007/s00167-022-06945-0 -
Clinics in Sports Medicine Jan 2022Through this article, the authors aim to summarize the techniques performed on both first time and recurrent skeletally immature patients experiencing patellar... (Review)
Review
Through this article, the authors aim to summarize the techniques performed on both first time and recurrent skeletally immature patients experiencing patellar dislocation. This article focuses on several key points, such as the importance of medial patellofemoral ligament femoral insertions being distal to the growth plate and performing extensive lateral release and quadricep tendon lengthening in cases of obligatory dislocation. Although acknowledging the procedures discussed cannot be considered for all patients, as individuals with open growth plates may require additional operative time, in many cases these techniques yield high rates of success.
Topics: Humans; Knee Joint; Ligaments, Articular; Patellar Dislocation; Patellofemoral Joint; Tendons
PubMed: 34782079
DOI: 10.1016/j.csm.2021.07.004 -
The American Journal of Sports Medicine Dec 2023Adolescents who experience a patellar dislocation have an elevated risk of patellofemoral posttraumatic osteoarthritis. Magnetic resonance imaging (MRI)-based T1ρ...
BACKGROUND
Adolescents who experience a patellar dislocation have an elevated risk of patellofemoral posttraumatic osteoarthritis. Magnetic resonance imaging (MRI)-based T1ρ relaxation times were measured for adolescents to evaluate patellofemoral cartilage after patellar dislocation. Long T1ρ relaxation times are an indicator of cartilage degradation.
HYPOTHESIS
The primary hypothesis is that patellofemoral cartilage T1ρ relaxation times will be elevated in the acute phase after patellar dislocation. The secondary hypothesis is that T1ρ relaxation times will be higher for knees with multiple rather than single dislocations due to repeated traumatic injury.
STUDY DESIGN
Cross-sectional study; Level of evidence, 3.
METHODS
In total, 23 adolescents being treated for a recent patellar dislocation, 13 for a first-time dislocation (47 ± 38 days since most recent dislocation) and 10 for multiple dislocations (55 ± 24 days since most recent dislocation), and 10 healthy controls participated in MRI-based T1ρ relaxation time mapping. For multiple regions of the patellofemoral joint, mean T1ρ values were compared between the 3 groups with multiple group comparisons and post hoc tests. T1ρ relaxation times were also correlated against measures of patellofemoral anatomy and alignment for single and multiple dislocations. Statistical significance was set at < .05.
RESULTS
T1ρ relaxation times were significantly longer for injured knees (single and multiple dislocations) than controls at the medial and central patella and central trochlear groove. For the regions on the patella, significant differences between injured and control knees exceeded 15%. No significant differences were identified between single and multiple dislocations. For the initial dislocation group, T1ρ relaxation times within multiple regions of the patellofemoral joint were significantly correlated with lateral patellar alignment or patellar height.
CONCLUSION
Elevated patellofemoral cartilage T1ρ relaxation times are consistent with a high risk of long-term patellofemoral osteoarthritis for adolescents who experience patellar dislocations. T1ρ relaxation times were elevated for multiple regions of patellofemoral cartilage. T1ρ relaxation times were expected to increase with additional dislocation episodes, but relaxation times after single and multiple dislocations were similar. After a first dislocation, parameters related to patellar maltracking were correlated with cartilage degradation.
Topics: Humans; Adolescent; Patellar Dislocation; Cross-Sectional Studies; Cartilage; Patellofemoral Joint; Patella; Osteoarthritis, Knee; Joint Dislocations; Bone Diseases; Magnetic Resonance Imaging
PubMed: 37897349
DOI: 10.1177/03635465231205562 -
The Surgeon : Journal of the Royal... Oct 2021The knowledge of the anatomy and biomechanics of patellar stabilizers is mandatory to achieve good clinical results with surgical reconstructive procedures. Few articles... (Review)
Review
BACKGROUND
The knowledge of the anatomy and biomechanics of patellar stabilizers is mandatory to achieve good clinical results with surgical reconstructive procedures. Few articles provide clear anatomical and biomechanical picture of medial patello-tibial ligament (MPTL).
METHODS
After a systematic review of the literature we selected in vivo or ex vivo studies providing anatomical or biomechanical measurements. We included 7 studies about MPTL anatomy for a total of 96 knees and 4 biomechanical studies.
RESULTS
The MPTL is a true ligament and important component of the medial patellar stabilizers, together with the medial patello-femoral ligament (MPFL) and medial patello-meniscal ligament. The contribution of MPTL on restriction forces of the patello-femoral joint is still unclear. Quadriceps, patellar, semitendinous and gracilis tendons are adequate grafts for surgical MPTL reconstruction.
CONCLUSIONS
MPTL is a well defined anathomical structure and histologically can be considered a ligament. It plays an important role in patellar stability especially it has a main role on patellar rotation and tilt instead on shift.
Topics: Biomechanical Phenomena; Humans; Joint Instability; Ligaments, Articular; Patella; Patellar Dislocation; Plastic Surgery Procedures
PubMed: 33121878
DOI: 10.1016/j.surge.2020.09.005 -
Korean Journal of Radiology Jun 2022Patellofemoral instability (PFI) is common in pediatric knee injuries. PFI results from loss of balance in the dynamic relationship of the patella in the femoral... (Review)
Review
Patellofemoral instability (PFI) is common in pediatric knee injuries. PFI results from loss of balance in the dynamic relationship of the patella in the femoral trochlear groove. Patellar lateral dislocation, which is at the extreme of the PFI, results from medial stabilizer injury and leads to the patella hitting the lateral femoral condyle. Multiple contributing factors to PFI have been described, including anatomical variants and altered biomechanics. Femoral condyle dysplasia is a major risk factor for PFI. Medial stabilizer injury contributes to PFI by creating an imbalance in dynamic vectors of the patella. Increased Q angle, femoral anteversion, and lateral insertion of the patellar tendon are additional contributing factors that affect dynamic vectors on the patella. An imbalance in the dynamics results in patellofemoral malalignment, which can be recognized by the presence of patella alta, patellar lateral tilt, and lateral subluxation. Dynamic cross-sectional images are useful for in vivo tracking of the patella in patients with PFI. Therapeutic approaches aim to restore normal patellofemoral dynamics and prevent persistent PFI. In this article, the imaging findings of PFI, including risk factors and characteristic findings of acute lateral patellar dislocation, are reviewed. Non-surgical and surgical approaches to PFI in pediatric patients are discussed.
Topics: Child; Humans; Joint Instability; Knee Joint; Patella; Patellar Dislocation; Patellofemoral Joint
PubMed: 35555883
DOI: 10.3348/kjr.2021.0577 -
The Knee Oct 2023Treatment of patellar instability remains up for debate, and a combination of tibial tubercle osteotomy and medial patellofemoral ligament reconstruction (MPFLr) of the... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Treatment of patellar instability remains up for debate, and a combination of tibial tubercle osteotomy and medial patellofemoral ligament reconstruction (MPFLr) of the medial patellofemoral ligament (MPFL) has become the mainstay treatment for recurrent lateral patellar dislocation. Due to limited small studies, there remains a variety of surgical techniques still being practiced. The use of MPFL reconstruction, in isolation, has demonstrated promise.
PURPOSE
The purpose of this systematic review and meta-analysis is to investigate if isolated medial patellofemoral ligament reconstruction (iMPFLr) can safely and efficaciously restore knee stability and to present the patient demographics, surgical techniques, graft choices, clinical outcomes, and complications after iMPFLr for recurrent patellar dislocation (RPD).
METHODS
A review of the current literature according to Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines, yielded 299 abstracts. Twenty-seven articles met the inclusion/exclusion criteria accounting for 1200 patients. Data was pooled and analyzed focusing on patient demographics, graft type used, Kujala, International Knee Documentation Committee (IKDC), Lysholm, Tegner, and complications.
RESULTS
Across all studies the weighted mean age was found to be an average of 24.5 years, BMI was 24.9 kg/m, follow-up was 47.3 months, as 67% were female, TT-TG distance was 15.3 mm, and Caton Deschamps index 1.11. The pooled effect size difference of pre versus post assessment of Kujala was -2.8, IKDC was -4.5, Lysholm was -6.4, and Tegner was -0.74. The pooled complication rate was found to be 8% across all included studies. A subgroup analysis was also performed, specifically looking at how single bundle, double bundle, gracilis, semitendinosus and knee angle during fixation effect outcome data.
CONCLUSION
This systematic review and meta-analysis demonstrates that isolated MPFL reconstruction is a safe and effective treatment for recurrent patellar dislocations. Given the efficacy of isolated MPFL reconstruction, future investigations should aim to uncover the exact TT-TG distance, trochlear dysplasia, and patella alta grade for selecting patients to undergo this procedure. Furthermore, more primary research needs to be conducted on this topic due to the overall lack of published data from randomized controlled studies and no broad standardization of outcome measurements.
LEVEL OF EVIDENCE
(4) Systematic Review and Meta-Analysis.
Topics: Humans; Female; Young Adult; Adult; Male; Patellar Dislocation; Patellofemoral Joint; Joint Instability; Knee Joint; Joint Dislocations; Ligaments, Articular; Patella
PubMed: 37531844
DOI: 10.1016/j.knee.2023.07.003 -
Knee Surgery, Sports Traumatology,... Oct 2022Trochlear dysplasia has been recognized as the most common factor in patients with patellofemoral dislocation. Trochleoplasty is a surgical procedure whose primary goal... (Review)
Review
PURPOSE
Trochlear dysplasia has been recognized as the most common factor in patients with patellofemoral dislocation. Trochleoplasty is a surgical procedure whose primary goal is to modify the femoral trochlea's abnormal shape in patients suffering from patellar instability, requiring good surgical skills, correct indication, and accurate patient information.
METHODS
The review aims to describe preoperative planning, patient selection, most common surgical techniques, and clinical results of trochleoplasty in patellar instability in a reproducible manner.
RESULTS
Trochleoplasty can be considered a general term to describe a group of different procedures that reduce trochlear dysplasia's impact on patellar instability, aiming to restore patella-trochlear congruency, remove the supratrochlear bump, allowed a new groove positioning and are generally associated with other procedures. Recent studies showed satisfactory long-term results with the restoration of patellar stability, improving radiological findings of patellofemoral instability.
CONCLUSION
Trochleoplasty is a technically demanding technique, requiring careful patient selection, detailed knowledge, and surgical skills to avoid severe complications. Good patient satisfaction with a low risk of significant complications such as patellofemoral arthritis has been revealed. In conclusion, trochleoplasty should be systematically included in the treatment of patellar dislocation, if indicated.
LEVEL OF EVIDENCE
V.
Topics: Humans; Joint Instability; Patella; Patellar Dislocation; Patellofemoral Joint; Patient Satisfaction
PubMed: 35355088
DOI: 10.1007/s00167-022-06954-z -
Radiology Nov 2023
Topics: Humans; Patellar Dislocation; Tomography, X-Ray Computed
PubMed: 37934091
DOI: 10.1148/radiol.231465 -
Knee Surgery, Sports Traumatology,... Aug 2019The scientific literature concerning the anatomy of medial soft-tissue stabilizers of the patella is growing exponentially. Much of the surgical literature has focused... (Review)
Review
PURPOSE
The scientific literature concerning the anatomy of medial soft-tissue stabilizers of the patella is growing exponentially. Much of the surgical literature has focused on the role of the medial patellofemoral ligament (MPFL) and techniques to reconstruct it, yet our understanding of its anatomy has evolved during the past several years. Given this, we report on the current understanding of medial patellofemoral anatomy and implications for reconstruction.
METHODS
Current and historical studies of medial patellar anatomy were reviewed, which include the MPFL and medial quadriceps tendon femoral ligament (MQTFL), as well as that of the distal medial patellar restraints, the medial patellotibial ligament (MPTL) and medial patellomeniscal ligament (MPML). In addition to the reported findings, the authors' anatomic descriptions of each ligament during their dissections were identified and recorded.
RESULTS
Despite the name of the MPFL, which implies that the ligament courses between the femur and patella, recent studies have highlighted the proximal MPFL fibers that attach to the quadriceps tendon, known as the MQTFL. The MPFL and MQTFL have also been referred to as the medial patellofemoral complex, reflecting the variability in anatomical attachment sites. The MPFL accounts for only half of the total restraint to lateral patellar displacement, and the remaining contributions to patellar stability are derived from the combination of the MPTL and MPML, which function primarily in greater degrees of knee flexion.
CONCLUSION
The understanding of the complexity of the medial patellar stabilizers continues to evolve. Although MPFL reconstruction is gaining wide acceptance as a procedure to treat patellar instability, it is important to recognize the complex and changing understanding of the anatomy of the medial soft-tissue stabilizers and the implications for reconstruction.
LEVEL OF EVIDENCE
V.
Topics: Biomechanical Phenomena; Humans; Joint Instability; Ligaments, Articular; Patellar Dislocation; Patellofemoral Joint; Quadriceps Muscle; Tendons
PubMed: 30370440
DOI: 10.1007/s00167-018-5266-y