Diagnosis and treatment of recurrent patellar dislocation with knee extensor device combined with rearrangement.

OBJECTIVE: This study aimed to investigate the clinical effects of combining knee extension mechanism (EM) with rearrangement in the treatment of recurrent patellar dislocation (RPD). PATIENTS AND METHODS: Eighty-four patients with RPD admitted to the First Affiliated Hospital of Kunming Medical University were included. In this work, all patients received routine computed tomography (CT) examinations. In addition, the evaluation factors of EM combined with rearrangement therapy in RPD patients were analyzed using logistic regression. RESULTS: Lysholm and Kujula scores, femoral canal width, patellar canal width, patellar tilt angle (PTA), and lateral patellar displacement (LPD) were significantly increased at 1 and 3 years after treatment (p < 0.05). LPA was significantly decreased, while the tibial tuberosity trochlear groove of the femur (TT-TG) demonstrated no considerable differences (p > 0.05). The good rate of the short-term Insall-Salvati index was 78.6%, and that of the long-term Insall-Salvati index was 76.1%. The combination of the knee extension device and rearrangement therapy has a higher rate of short-term and long-term Insall-Salvati index (ISI) excellence. In addition, the range of motion of the knee joint increased significantly, and the Q Angle decreased significantly (p < 0.05). Logistic regression analysis showed that age and ISI were highly correlated with the evaluation of therapeutic effects in patients with RPD. CONCLUSIONS: EM combined with rearrangement in the treatment of RPD had positive short-term and long-term efficacy, high application value, and age, which can be popularized in clinical applications and have positive diagnostic value.

[Current therapy progress on the acute patellar dislocation].

The treatment of acute patellar dislocation remains a topic of debate among orthopedic surgeons. While conservative treatment has traditionally been favored, recent studies have highlighted the high redislocation rate, prompting a reevaluation of treatment strategies. Current approaches recognize the importance of addressing not only the knee joint but also associated factors contributing to instability. Surgical intervention, particularly focusing on restoring patellar stability through medial patella-femoral ligament (MPFL), repair or reconstruction, has gained popularity. MPFL reconstruction can provide long-term stability of the patella, but further research is needed. When acute patellar dislocation is associated with abnormal bony factors, multiple surgical modalities are often required, with the goal of restoring the normal trajectory of the patella, maintaining the stability of the patellofemoral joint, and optimizing knee joint function. This review provides an overview of advances in the treatment of acute patellar dislocation and related problems, so as to provide reference for clinicians.

Predictive Scoring for Recurrent Patellar Instability After a First-time Patellar Dislocation.

PURPOSE: Patellofemoral instability is a common acute knee injury seen in the pediatric population. First-time patellar dislocations usually undergo conservative management, but ~15% to 80% of patients experience recurrent instability. This study aims to develop a prediction model using radiographic parameters of the patellofemoral joint seen on computed tomography scans in different degrees of knee flexion, to determine the risk of recurrence after the first episode of patellofemoral instability. METHODS: A 12-year retrospective case-control study was performed. All patients in a single institution aged 18 years or younger who had a computed tomography patellar tracking scan performed for patellar instability were included. Predictors included in the score were determined through backward logistic regression and compared using receiver operating characteristic curve analysis. RESULTS: This study revealed that recurrent dislocation in first-time patellofemoral dislocation could be accurately predicted using the prediction score that consisted of age, tibial tubercle-trochlear groove distance and congruence angle at 10- and 20-degree flexion. The sensitivity of the score was 100% and specificity was 73.3%. Three diagnostic zones were identified and used to categorize patients into low-, intermediate-, and high-probability groups. CONCLUSION: This study presented a scoring system that incorporated radiographic knee kinematics in the risk assessment for recurrent patellofemoral instability for patient stratification. The scoring system could guide the decision for early surgical intervention after the first-episode patellofemoral dislocation for patients at high risk of recurrent patellofemoral dislocation.

Blood flow Restriction training After patellar INStability (BRAINS 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.

Patellar instability: will my patella dislocate again?

PURPOSE OF REVIEW: The incidence of patellar instability in pediatric patients ranges is 50-100 in 100,000 patients per year. Risk of recurrent dislocations however has been cited from 8.6% to 88% depending on individual patient factors. This manuscript highlights the demographical, historical, and anatomic factors associated with recurrent patellar instability following a first-time patella dislocation in the pediatric population. RECENT FINDINGS: In recent years, various studies have focused on identifying risk factors for recurrent patellar instability following a primary patellar dislocation. A mix of patient factors, including age of first dislocation, patella alta, elevated tibial tubercle to trochlear groove and trochlear dysplasia have all been noted in the literature, which have helped to develop various scoring tools to predict recurrent dislocation following nonoperative treatment. SUMMARY: Risk of recurrent patellar instability in patients who have previously suffered a patellar dislocation can be due to many factors. These risk factors should be used and applied to a variety of risk scores in order to provide physicians and healthcare providers with a tool to counsel patients and families on their patellar redislocation risk and help guide further management.

[Primary and recurrent patellar dislocation: recommendation for diagnostic evaluation, risk stratification and treatment]. / Akute und chronische Patellainstabilität ­ Empfehlungen zur Diagnostik, Risikostratifizierung und Therapie.

The dogma that (every) primary patellar dislocation should be treated non-operatively is considered outdated. Therefore, every first-time dislocation, as well as every recurrent dislocation, should be fully diagnosed with regard to the injury pattern and anatomically predisposing risk factors. This enables the use of risk stratification models to assess the risk of recurrent episodes of instability, thereby supporting the clinical decision-making process. The reconstruction of the MPFL can be considered an established and successful treatment strategy for patellar instability. However, the additional correction of bony risk factors is often useful. In this context, the preoperative grading of the J sign and dynamic assessment of patellar instability (dynamic apprehension test) are of utmost importance. These findings, combined with the radiographic imaging findings, can be used as a clinical decision aid for a bony correction procedure.

Patella Sleeve Fracture with Medial Patellofemoral Ligament Tear and Lateral Femoral Condyle Fracture in an Adolescent: A Case Report.

CASE: A 12-year-old boy sustained a patella sleeve fracture of the superior pole, medial patellofemoral ligament tear, and lateral femoral condyle fracture after a direct contact sledding injury. He was managed nonoperatively with 5 weeks of cylinder cast immobilization with transition to a hinged knee brace and physiotherapy. By 3 months, he returned to sport activity without patellar instability. CONCLUSION: This is the first case to describe simultaneous development of these 3 injuries in an adolescent. We recommend that patients with patella sleeve fracture undergo magnetic resonance imaging to assess for local soft-tissue injury because this may influence treatment decisions.

Development of a Multivariable Model Based on Individual Risk Factors for Recurrent Lateral Patellar Dislocation.

BACKGROUND: Nonoperative treatment after first-time patellar dislocation is the standard of care. There is evidence that certain patients may be at high risk for recurrent instability. The aim of this study was to develop a multivariable model to guide management of patients based on their individual risk of recurrent dislocation. METHODS: A multivariable model was developed using 291 patients from 4 institutions to identify which patients were at higher risk for recurrent patellar dislocation within 2 years. This model was informed by a univariable logistic regression model developed to test factors based on the patient's history, physical examination, and imaging. The discriminatory ability of the model to classify who will or will not have a recurrent dislocation was measured using the area under the receiver operating characteristic curve (AUC). RESULTS: Age, a history of a contralateral patellar dislocation, skeletal immaturity, lateral patellar tilt, tibial tubercle-trochlear groove (TT-TG) distance, Insall-Salvati ratio, and trochlear dysplasia were the most important factors for recurrent patellar dislocation. Sex, mechanism of injury, Caton-Deschamps ratio, sulcus angle, inclination angle, and facet ratio were not factors for recurrent dislocation. The overall AUC for the multivariable model was 71% (95% confidence interval [CI]: 64.7% to 76.6%). CONCLUSIONS: Optimizing the management of lateral patellar dislocation will improve short-term disability from the dislocation and reduce the long-term risk of patellofemoral arthritis from repeated chondral injury. This multivariable model can identify patients who are at high risk for recurrent dislocation and would be good candidates for early operative treatment. Further validation of this model in a prospective cohort of patients will inform whether it can be used to determine the optimal treatment plan for patients presenting with an initial patellar dislocation. Until validation of the model is done with new patients, it should not be used in clinical practice. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Conservative Versus Surgical Treatment for Primary Patellar Dislocation.

BACKGROUND: Primary patellar dislocation is often the initial manifestation of patellofemoral instability. Its long-term consequences can include recurrent dislocation and permanent dysfunction of the knee joint. There is no consensus on the optimal treatment of primary patellar dislocation in the relevant literature. The main prerequisite for a good long-term result is a realistic assessment of the risk of recurrent dislocation. METHODS: We carried out a systematic literature search in OvidSP (a search engine for full-text databases) and MEDLINE to identify suitable stratification models with respect to the risk of recurrent dislocation. RESULTS: In the ten studies included in the current analysis, eight risk factors for recurrence after primary patellar dislocation were identified. Six studies revealed a higher risk in younger patients, particularly those under 16 years of age. The sex of the patient had no clear influence. In two studies, bilateral instability was identified as a risk factor. Two anatomical risk factors-a high-riding patella (patella alta) and trochlear dysplasia-were found to have the greatest influence in six studies. In a metaanalysis of five studies, patella alta predisposed to recurrent dislocation with an odds ratio (OR) of 4.259 (95% confidence interval [1.9; 9.188]). Moreover, a pathologically increased tibial tuberosity to trochlear groove (TT-TG) distance and rupture of the medial patellofemoral ligament (MPFL) on the femoral side were associated with higher recurrence rates. Patients with multiple risk factors in combination had a very high risk of recurrence. CONCLUSION: The risk of recurrent dislocation after primary patellar dislocation is increased by a number of risk factors, and even more so when multiple such risk factors are present. Published stratification models enable an assessment of the individual risk profile. Patients at low risk can be managed conservatively; surgery should be considered for patients at high risk.

Conservative versus repair of medial patellofemoral ligament for the treatment of patients with acute primary patellar dislocations: A systematic review and meta-analysis.

PURPOSE: The aim of this study was to perform a meta-analysis to compare the effects of repair of medial patellofemoral ligament (MPFL) and conservative treatment in patients with acute primary patellar dislocation (PPD). METHOD: The databases we used to search the studies included MEDILINE, EMBASE, and Cochrane registry of controlled clinical trials. Five randomized controlled studies comparing the effects of MPFL repair versus conservative treatment with 300 acute PPD patients were included in the present meta-analysis. Primary outcome was redislocation rate and secondary outcomes included Kujala score, percentage of excellent or good subjective opinion, Tegner activity score, and knee injury and osteoarthritis outcome score (KOOS; pain, symptoms, and activities of daily living). RESULTS: The outcome of the Kujala score was statistically significant between the two treatments and indicated that MPFL repair had a higher Kujala score than conservative treatment in patients with acute PPD. There was no significant difference between the two treatments regarding the redislocation rate (p = 0.32), percentage of excellent or good subjective opinion (p = 0.15), Tegner activity score (p = 0.24), and KOOS (p > 0.05). CONCLUSIONS: Based on the available data, MPFL repair did not reduce the risk of redislocation nor did it produce any significantly better outcome based on the clinical manifestations, including anterior knee pain and knee activities. Only the Kujala score was improved by MPFL repair compared with conservative treatment.

Does surgical treatment produce better outcomes than conservative treatment for acute primary patellar dislocations? A meta-analysis of 10 randomized controlled trials.

PURPOSE: The objective of this study was to conduct the latest meta-analysis of randomized controlled trials (RCTs) that compare clinical results between surgery and conservative therapy of acute primary patellar dislocation (APPD), focusing on medial patellofemoral ligament (MPFL) reconstruction. METHODS: We performed a literature search in Embase, The Cochrane Library, PubMed, and Medline to identify RCTs comparing APPD surgical treatment with conservative treatment from the establishment of each database to January 2019. The methodological quality of each RCT was assessed independently by the two authors through the Cochrane Collaboration's "Risk of Bias" tool. Mean differences of continuous variables and risk ratios of dichotomous variables were computed for the pooled data analyses. The I2 statistic and the χ2 test were used to evaluate heterogeneity, with the significance level set at I2 > 50% or P < 0.10. RESULTS: Ten RCTs with a sum of 569 patients (297 receiving surgical treatment and 263 receiving conservative treatment) met the inclusion criteria for meta-analysis. Pooled data analysis showed no statistical difference in the field of subluxation rate, Kujala score, patient satisfaction, and frequency of reoperation between the two groups. Tegner activity score and recurrent dislocation rate in the conservative group were significantly higher than those in the surgically treated group. CONCLUSIONS: Conservative treatment may produce better outcomes than surgery for APPD in consideration of Tegner activity score. However, in view of limited research available, the interpretation of the discoveries should be cautious. More convincing evidence is required to confirm the effect of MPFL reconstruction.

Surgical versus conservative treatment for first patellofemoral dislocations: a meta-analysis of clinical trials.

INTRODUCTION: The first approach for acute patellar dislocation is still a debated topic. The purpose of the present study was to perform a meta-analysis evaluating the outcomes of the surgical approach compared to the conservative treatments for primary acute patellar dislocation. We hypothesize that a prompt surgical treatment may lead to better outcomes in terms of re-dislocations and quality of life. METHODS: This meta-analysis was performed according to the PRISMA guidelines. All the prospective clinical trials comparing surgical and conservative treatment for first acute patellofemoral dislocation were included in this study. For the methodological quality assessment, the PEDro appraisal score was adopted. For the risk of publication bias, the funnel plot was performed. The statistical analysis was performed using the Review Manager Software 5.3 (The Nordic Cochrane Collaboration, Copenhagen). RESULTS: The funnel plot detected a low risk of publication bias. According to the PEDro score, the methodological quality assessment was good. Data from 654 patients were collected, undergoing a mean of 53.8 ± 48.4 month follow-up. A total of 311 patients (17.66 ± 4.1 years old) were analyzed in the surgery group and 291 patients (19.25 ± 4.5 years old) in the conservative ones. The mean Kujala score resulted in greater favor of the surgery group (MD: 9.99%; P = 0.006). The analysis of the comparison of re-dislocations resulted in favor of the surgery group (OR: 0.41; P < 0.0001). The analysis of the comparison of persistent joint instability resulted in favor of the surgery group (OR: 0.41; P < 0.0001). CONCLUSIONS: Data from the present study encourage a prompt surgical approach for the first patellofemoral dislocation.

The Forgotten Joint Score-12 as a valuable patient-reported outcome measure for patients after first-time patellar dislocation.

BACKGROUND: The aim of this study is to assess joint awareness after first-time patellar dislocation using the Forgotten Joint Score-12 (FJS-12) and to compare performance of this measurement tool to acknowledged patient-reported outcome scores. METHODS: A retrospective analysis of patients with confirmed first-time patellar dislocation was performed. Patients were assessed with the FJS-12, the Kujala and the WOMAC scores. Reference values for the FJS-12 were obtained from a matched healthy control group with no history of previous knee joint pathology. We calculated Cronbach's alpha, assessed the ceiling effect for all scores, and calculated the Spearman correlation coefficient between them RESULTS: Fifty-six patients (mean follow-up 8.2 years, range 1.6-14.1) with a mean age of 26.4 years were analysed. Compared with the age- and gender-matched control group, the patellar dislocation group showed significantly lower (worse) mean FJS-12 scores (88 vs. 71, P < 0.001). Inter-score correlation between the FJS-12 and the Kujala was high (r = 0.74) and significant (P < 0.001), as well as between FJS-12 and WOMAC (r = 0.81, P < 0.001). Cronbach's alpha of the FJS-12 was 0.92 (95% confidence interval 0.90-0.94). The FJS-12 showed less ceiling effect (16%) compared with the Kujala score (23%) and the WOMAC score (32%). CONCLUSIONS: The concept of joint awareness has been successfully applied to a patient population after patellar dislocation. The FJS-12 showed less ceiling effect compared with the Kujala and the WOMAC scores, suggesting the score was able to capture subtle knee problems in patients after patellar dislocation.

Scoring system for optimal management of acute traumatic patellar dislocation: A multicenter study.

BACKGROUND: In first-time acute traumatic patellar dislocations, numerous anatomic and clinical factors are complicatedly associated and should be comprehensively considered for the optimal management of conservative or surgical intervention. The purpose of this study was to establish a scoring system, using a concept that is not complicated and easily used in clinic. METHODS: Of 131 first-time acute traumatic patellar dislocations, 81 patients (51 females, 30 males) with an average age of 19.6 (95%CI, 17.5-21.6) years and an average follow-up duration of 17.1 (95% CI, 12.3-21.9) months, who underwent conservative treatment after first-time dislocations, were reviewed. Based on the odds ratios applying logistic regression analysis, the scoring system was established. RESULTS: The scoring system (total: 10 points) had simple composition of age <20 (2 points), sports injury (1 points), hemarthrosis (1 points), and image findings of a bony fragment (3 points), lateral shift of the patella (1 points), and trochlear dysplasia (2 points). A threshold score of 6.5 was determined using the area under receiver operating characteristic curve of 0.893 (p < 0.0001). In logistic regression analysis, a score of ≥7 was shown to be a dominant factor for recurrence (OR = 27.1, p < 0.0001). Furthermore, the association between the score and recurrence risk was as follows: a score of ≤4 = low risk (1/21 cases, 5%); a score of 5-7 = medium risk (13/27 cases, 48%); a score of ≥8 = high risk (30/33 cases, 91%). CONCLUSIONS: Based on the simple scoring system, patients who scored ≥8 were considered suitable for surgical treatment because of the high rate of recurrence, whereas those who scored ≤4 were considered suitable for conservative treatment because of the low rate of recurrence.

Pediatric patellar dislocation.

Acute patellar dislocation affects approximately 1:1000 healthy children 9-15 years of age, and up to 50% are at risk for recurrent dislocations. In adults the condition is associated with long-term complications, such as osteoarthritis and impairment of knee function. However, literature describing the outcome in a pediatric population is sparse. The present review article evaluates the long-term effects on knee function and cartilage quality after traumatic patellar dislocation in childhood, and also to evaluate the reliability of two clinical tests of medio-lateral knee position, in healthy children.

Surgical treatment is better than non-surgical treatment for primary patellar dislocation: a meta-analysis of randomized controlled trials.

BACKGROUND: At present, the best treatment for primary patellar dislocation (PPD) has not been unified. Moreover, meta-analyses comparing the non-surgical and surgical treatments of PPD are lacking. Thus, we aimed to compare the clinical efficacy of surgical or non-surgical treatment of PPD. METHODS: Randomized controlled studies of surgical and non-surgical treatments of PPD from 1966 to 2018 were retrieved from the following databases: PubMed, EMBASE, Cochrane Library, Wanfang Database, China Knowledge Network, Google Scholar, and Weipu Database. We screened for literature that met the inclusion criteria and extracted useful data for our meta-analysis. RESULTS: Nine studies, involving 492 patients, met the inclusion criteria and were analyzed in this study. The recurrence rate of patellar dislocation in the surgical group was lower than that in the non-surgical group (P = 0.04]). Subgroup analysis according to the follow-up time showed that the Kujala score (P < 0.001) and lower recurrence rate of dislocation (P = 0.05) than the non-surgical group in the short term. Subgroup analysis according to surgical year showed that the surgical group get higher Kujala score (P < 0.001) and lower recurrence rate of dislocation (P = 0.01) than the non-surgical group in recent years. CONCLUSION: Surgical treatment can provide better clinical results in a short period of time, and patients may achieve good results within 10 years owing to the advances in surgical techniques and instruments. Thus, we recommend surgical treatment as the preferred treatment for primary patellar dislocation.

Implementation of a Prehospital Patella Dislocation Reduction Protocol.

Introduction: Acute patella dislocations account for up to 3% of all knee injuries. Prehospital care of patella dislocation often includes knee immobilization and pain management, but in the wilderness environment patella reductions are often performed by basic life support providers. Given the potential benefits of early reduction, the perceived low risk of harm and precedent with which the procedure can be performed, patella reduction was added to the EMT scope of practice in New York State. Our objective is to characterize the mechanism of patella related injuries and describe the success rate and complications experienced with the addition of a prehospital patella reduction protocol.Methods: This was a retrospective review of a voluntary, preexisting, quality assurance database of cases in which a patella reduction was attempted between October 1, 2016 and June 30, 2018.Results: 90 patients underwent an attempt at patella reduction at one of 52 EMS agencies during the study period. The most common mechanism was a sports-related injury. Patella reduction was successful 83/90 (92.2%). Median pain score was reduced from 10 to 2. There were no reported complications.Conclusion: While a convenience sample, our results provide preliminary evidence that patella reduction can be performed by EMS providers with infrequent complication and offers significant pain relief.

Treatment of First-time Patellar Dislocations and Evaluation of Risk Factors for Recurrent Patellar Instability.

Approximately one-third of skeletally mature patients with primary patellar dislocation will experience recurrent patellar instability over time. Because of the multifactorial combination of features contributing to overall stability of the patellofemoral joint, first-time patella dislocation presents a challenge to the treating physician. A detailed patient history, focused physical examination, and appropriate diagnostic imaging are essential for identifying risk factors for recurrent instability. Individual risk factors include young patient age, patella alta, trochlear dysplasia, and lateralization of the tibial tubercle. In combination these factors may pose even greater risk, and recently published predictive scoring models offer clinicians objective criteria to identify patients most at risk for recurrence. In patients at low risk of recurrence, nonoperative management can be effective, with "a la carte" surgical treatments gaining popularity in those with a higher than acceptable risk of re-dislocation.

Management of the first-time lateral patellar dislocation.

BACKGROUND: Little guidance exists on the management of the first-time patellar dislocation. The aim of this article was to review current guidance for management of this condition. METHODS: Recent meta-analyses, systematic reviews and current consensus documents relating to first-time patellar dislocation were sourced. An instructional lecture was then created and delivered at the acute knee injuries session at the British Orthopaedic Association 2019 annual conference, which was presented on behalf of the British Association for Surgery of the Knee. This article has been written based on this lecture. RESULTS: There is a paucity of literature relating to management of the first-time patellar dislocation. Many studies are of poor design, with inadequate follow-up, making it difficult to draw conclusions from them. However, based upon available information and consensus from working groups it is recommended that patients presenting with first-time dislocation should be assessed to ensure they have not sustained an alternative or associated injury that may require surgical intervention, be assessed and counselled for the risk of recurrent dislocation, and be referred for initial conservative treatment. Surgical stabilisation should be reserved for patients with recurrent instability. CONCLUSIONS: Most patients with a first-time patellar dislocation can be managed conservatively, having excluded associated injuries. Due to the poor quality of the literature, care must be taken interpreting the results of studies. It is clear that further research is required in this field.