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Cureus Oct 2023Acute patellar dislocation (PD) is usually a problem of adolescents and young adults. In most cases, it is a sports-related injury. It is the result of an indirect force... (Review)
Review
Acute patellar dislocation (PD) is usually a problem of adolescents and young adults. In most cases, it is a sports-related injury. It is the result of an indirect force on the knee joint, which leads to valgus and external rotation of the tibia relative to the femur. PD is unlikely to occur on a knee with normal patellofemoral joint (PFJ) anatomy. Acute PD consists of an acute injury of the ligamentous medial patellar stabilizers in the background of factors predisposing to patellar instability. These factors are classified into three groups. The first group refers to the integrity of the ligamentous medial patellar restraints, particularly, the medial patellofemoral ligament (MPFL). The second group refers to an abnormal PFJ anatomy, which renders the patella inherently unstable inside the trochlea. The third group refers to the overall axial and torsional profile of the lower limb and to systemic factors, such as ligament laxity and neuromuscular coordination of movement. PD at a younger age is associated with an increased number and severity of patellar instability predisposing factors and lower stress to dislocate the patella. Acute primary PD is usually treated conservatively, while surgical treatment is reserved for recurrent PD. The aim of treatment is to restore the stability and function of the PFJ and to reduce the risk of patellar redislocation. Surgical procedures to treat patellar instability are classified into non-anatomic and anatomic procedures. Non-anatomic procedures are extensor mechanism realignment techniques that aim to center the patella into the trochlear groove. Anatomic procedures aim to restore the PFJ anatomy (ruptured ligaments, osteochondral fractures), which has been severed after the first incident of PD. Anatomic procedures, especially MPFL reconstruction, are more effective in preventing recurrent PD, compared with non-anatomic techniques. Theoretically, all factors that affect PFJ stability should be evaluated and, if possible, addressed. This is practically impossible. Considering that the MPFL ruptures in almost all PDs, MPFL reconstruction is the primary procedure, which is currently selected by most surgeons as a first-line treatment for patients with recurrent PD. Restoration of the axial and torsional alignment of the lower limbs is also increasingly implemented by surgeons. Non-anatomic surgical techniques, such as tibial-tuberosity osteotomy, are used as an adjunct to anatomic procedures. In the presence of multiple PFJ instability factors, acute MPFL reconstruction may be the treatment of choice for acute primary PD as well. Skeletal immaturity of the patient precludes osseous procedures to avoid premature physis closure and subsequent limb deformity. Unfortunately, restoration of the patient's previous activity level or participation in more strenuous sports is questionable and not easy to predict. In the case of competitive athletes, PD may prevent participation in elite levels of sports.
PubMed: 38021800
DOI: 10.7759/cureus.46743 -
Current Reviews in Musculoskeletal... Jul 2023This review focuses on the etiology, diagnosis, and management of patellar instability in pediatric patients. (Review)
Review
PURPOSE OF REVIEW
This review focuses on the etiology, diagnosis, and management of patellar instability in pediatric patients.
RECENT FINDINGS
Radiological outcomes such as tibial-tubercle to trochlear groove (TT-TG) distance used in diagnosis are subject to factors of influence such as femoral anteversion and knee flexion angle, and new measure such as tibial-tubercle to posterior cruciate ligament distance as well as TT-TG/trochlear width (TT-TG/TW) are under investigation. To prevent recurrent instability, surgical intervention for acute patellar dislocations may be advantageous compared to conservative management. Patellar instability is a common pathology found in pediatric cohorts. Diagnosis can be performed via a combination of history, physical examination maneuvers, and radiological risk factors such as patella alta, patellar tilt, trochlear dysplasia, and elevated TT-TG distances. Current literature advocates the usage of additional radiological measures to TT-TG such as TT-TG/TW, especially as TT-TG varies with age in younger patients. Recent literature potentially suggests the utilization of surgical procedures such as MPFL reconstruction or repair for acute dislocations in the hope of preventing recurrent instability. Special indications for pediatric patients include osteochondral fracture identification to help prevent patellofemoral osteoarthritis. A comprehensive workup and understanding of current literature can aid clinicians in aiming to prevent recurrent patellar dislocation in pediatric patients.
PubMed: 37071284
DOI: 10.1007/s12178-023-09836-0 -
Current Reviews in Musculoskeletal... Jan 2024Acute knee injuries are commonly encountered in both the clinical and sideline setting and may be treated operatively or non-operatively. This article describes an... (Review)
Review
PURPOSE OF REVIEW
Acute knee injuries are commonly encountered in both the clinical and sideline setting and may be treated operatively or non-operatively. This article describes an evidence-based approach to non-operative acute knee injury. This includes history, physical exam, imaging, and initial management. In addition, the non-operative management of three such injuries-ligament injury, meniscus injury, and patellar dislocation injury-will be discussed via a case-based practical approach.
RECENT FINDINGS
Aside from grade III ACL tears, most acute knee ligament injuries, especially in the absence of other concurrent injuries, can be treated non-operatively. There is new evidence that acute traumatic meniscus tears in those younger than 40 can be successfully treated non-operatively and can do equally, as well as those that undergo surgery, at 1 year out from injury. Based on the current literature, a short period of knee bracing in extension with progression to weightbearing to tolerance is recommended after initial patellar dislocation. Many of the most common acute knee injuries, including MCL tears, meniscus tears, and patellar dislocations, can be managed non-operatively. A detailed systemic approach to initial evaluation, including pertinent history, physical exam, and appropriate imaging, is essential and complementary to the subsequent non-operative treatment algorithm.
PubMed: 38095838
DOI: 10.1007/s12178-023-09875-7 -
Current Reviews in Musculoskeletal... Nov 2023Obligatory dislocation of the patella (also known as habitual dislocation) is a rare subset of patellofemoral instability in which the patella dislocates every time the... (Review)
Review
PURPOSE OF REVIEW
Obligatory dislocation of the patella (also known as habitual dislocation) is a rare subset of patellofemoral instability in which the patella dislocates every time the knee is flexed. The problem arises due to contracture of the quadriceps muscles. Soft tissue lengthening procedures such as quadriceps tendon lengthening are the mainstay of treatment, in contrast to medial patellofemoral reconstruction (MPFL-R) for the more common recurrent lateral patellar dislocation. The current review explores the existing literature surrounding the pathophysiology and treatment strategies for this unique cause of knee instability.
RECENT FINDINGS
Flexion dislocation of the knee often presents in children when they begin to walk. It is also termed obligatory or habitual because the patella dislocates laterally with each flexion and extension cycle of the knee. In contrast to other forms of patellar dislocation, the displacement is painless in obligatory dislocation. Likewise, the underlying biomechanical cause of this issue is related to contracture of tissues lateral to the patella rather than disruption of medial soft tissues as seen in recurrent/traumatic dislocation or subluxation of the patella. A number of procedures have been described for management of obligatory dislocation of the patella, with the general consensus that a combination of procedures including release/lengthening of the proximal lateral soft tissues as a critical component for a successful outcome. Soft tissue release/lengthening has been performed for over 50 years to treat obligatory dislocation of the patella. This procedure must be used in combination with other proximal and distal reconstructive with careful intraoperative assessment of knee flexion and patellar tracking for satisfactory outcomes. Further research using standardized outcome measures is needed to identify the optimal step-wise approach in treatment of obligatory patellar dislocation.
PubMed: 37665483
DOI: 10.1007/s12178-023-09865-9 -
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 -
Knee Surgery & Related Research Jun 2023This study sought to clarify treatment evidence to treat patellar dislocation by evaluating which treatment could yield better improvement of clinical outcomes for acute... (Review)
Review
PURPOSE
This study sought to clarify treatment evidence to treat patellar dislocation by evaluating which treatment could yield better improvement of clinical outcomes for acute patellar dislocation in children and adolescents 18 years of age or younger.
MATERIALS AND METHODS
MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials electronic databases were searched for relevant articles comparing clinical outcomes of conservative and surgical treatments for acute patellar dislocation in children and adolescents published from March 2008 to August 2022. Data searching, extraction, analysis, and quality assessment were performed on the basis of the Cochrane Collaboration guidelines. The quality assessment of each study was investigated using the Physiotherapy Evidence Database (PEDro) critical appraisal scoring system and Newcastle-Ottawa Quality Assessment Scale scores. To calculate the overall combined effect size for each outcome, Review Manager Version 5.3 (The Cochrane Collaboration, Software Update, Oxford) was employed.
RESULTS
Three randomized controlled trials (RCTs) and one prospective study were investigated. In terms of pain [mean difference (MD) 6.59, 95% confidence interval (CI) 1.73-11.45, I 0%], there were significantly better outcomes in conservative group. Nevertheless, there were no significant differences in any evaluated outcomes such as redislocation [risk ratio (RR) 1.36, 95% CI 0.72-2.54, I 65%], Kujala score (MD 3.92, 95% CI -0.17 to 8.01, I 0%), Tegner score (MD 1.04, 95% CI -0.04 to 2.11, I 71%), or subjective results (RR 0.99, 95% CI 0.74-1.34, I 33%) between conservative and surgical treatment groups.
CONCLUSIONS
Despite better pain outcomes with conservative group, the present study revealed no significant differences in clinical outcomes between conservative treatment and surgical treatment in children and adolescents with acute patellar dislocation. Since there are no significant differences in clinical outcomes between the two groups, routine surgical treatment is not advocated for treating acute patellar dislocation in children and adolescents.
PubMed: 37349852
DOI: 10.1186/s43019-023-00189-z