Patellar Instability Management: A Survey of the International Patellofemoral Study Group

Background: Although patellofemoral instability is among the most prevalent knee disorders, the management of patients with this condition is complex and remains variable, given the lack of long-term, high-level clinical outcome studies to compare various operative and nonoperative modalities. Purpose: To discover a consensus within treatment controversies in patellofemoral instability among experienced knee surgeons with a specific interest in the patellofemoral joint. Study Design: Expert opinion; Level of evidence, 5. Methods: A 3-step modified Delphi technique was used to establish a consensus. A 34-question, case-based online survey regarding patellofemoral instability was distributed to all active members of the International Patellofemoral Study Group. Consensus statements were generated if at least 66% of the respondents agreed and then redistributed to the same panel. Modifications to the consensus statements were made based on the iterative feedback process until no discordance was encountered in the third stage. Results: Eight consensus statements were achieved. Nonoperative management is the current standard of care for a first-time dislocation in the absence of an osteochondral fragment or loose body requiring excision (100% agreement). In patients with a first-time dislocation with an operative osteochondral fracture requiring excision or repair, patellar instability should be addressed concurrently (89% agreement). Recurrent instability should be treated surgically, with most surgeons favoring medial reconstruction (77%-86% agreement). While there is general agreement that bony procedures should be performed to correct underlying bony deformities, there is no consensus regarding the most appropriate type of procedure performed. Lateral release should not be performed in isolation for the treatment of patellar instability (89% agreement). Conclusion: Despite the consensus generated in this study, our current understanding remains limited by a lack of high-level evidence as well as the numerous complex variables influencing treatment decision making. High-quality, multicenter randomized controlled trials, particularly those directly comparing specific surgical treatment methods while controlling for underlying risk factors, are needed to address these areas of uncertainty.

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How Does Isolated Medial Patellofemoral Ligament Reconstruction Influence Patellar Height?

The American Journal of Sports Medicine ◽

10.1177/0363546520902132 ◽

2020 ◽

Vol 48 (4) ◽

pp. 895-900 ◽

Cited By ~ 1

Author(s):

Francesco Luceri ◽

Julien Roger ◽

Pietro Simone Randelli ◽

Sébastien Lustig ◽

Elvire Servien

Keyword(s):

Patellar Instability ◽

Medial Patellofemoral Ligament ◽

Case Series ◽

Patellofemoral Instability ◽

Patellar Height ◽

Patella Alta ◽

Level Of Evidence ◽

Normal Limits ◽

Patient Reported ◽

History Of

Background: Reconstruction of the medial patellofemoral ligament (MPFL) is the gold standard treatment for recurrent patellar dislocation. Patella alta has been reported in about half of patients with recurrent patellofemoral instability. Hypothesis: MPFL reconstruction (MPFLr) has a beneficial role in the correction of patellar height in patients with mild patella alta (Caton-Deschamps index [CDI] between 1.20 and 1.40). Study Design: Case series; Level of evidence, 4. Methods: Skeletally mature patients, with no history of previous or concomitant knee surgical procedures, who underwent isolated MPFLr using hamstring autograft for recurrent patellar instability between 2005 and 2018, were included in this study. The authors calculated CDI, modified Insall-Salvati index (MISI), and Blackburne-Peel index (BPI) ratios. Measurements done by 2 independent observers were calculated and used to compare pre- and postoperative patellar height (patella alta: CDI >1.20). Results: A total of 89 patients (95 knees) were included in the study, with a mean age of 25.0 years (range, 15.0-45.0 years). There were 70% women and 30% men. We found patella alta in 35.8% of cases preoperatively. Among them, 79.4% had reduced patellar height indices, within normal limits, postoperatively (mean follow-up, 18.4 ± 12.0 months). All the ratios showed a significant reduction in patellar height after surgery (CDI: 0.19 [range, –0.05, 0.60]; MISI: 0.22 [–0.14, 0.76]; BPI: 0.18 [–0.08, 0.59]; P < .00001). The CDI of 79.4% of the study knees was reduced to within normal limits postoperatively. The CDI was maintained within normal limits postoperatively in 93.4% of the knees with normal patellar height and reduced to normal in 50% of the knees with severe patella alta before surgery . No patient reported patella infera before surgery, whereas this condition was found in 8.2% of study patients postoperatively. A moderate correlation was reported between preoperative radiographic indices and their reduction after surgery (CDI: P < .001, ρ = 0.39; MISI: P < .001, ρ = 0.39; BPI: P < .001, ρ = 0.48). Conclusion: The higher the preoperative patellar height, the more important is the lowering effect of MPFLr using the hamstring for patellar instability. Bony procedures should not be indicated in patients with patellar instability and a CDI between 1.20 and 1.40.

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Noniatrogenic Medial Patellar Dislocations: Case Series and International Patellofemoral Study Group Experience

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967120985530 ◽

2021 ◽

Vol 9 (2) ◽

pp. 232596712098553

Author(s):

Alexander E. Loeb ◽

Jack Farr ◽

Shital N. Parikh ◽

Andrew J. Cosgarea

Keyword(s):

Risk Factors ◽

Patellar Dislocation ◽

Patellar Instability ◽

Case Series ◽

Collegiate Athletes ◽

Study Group ◽

Case Review ◽

Level Of Evidence ◽

Lateral Direction ◽

Ehlers Danlos Syndrome

Background:Most patellar dislocations occur in a lateral direction because of a summed lateral force vector and predisposing anatomic risk factors. Medial patellar instability is rare and is a well-recognized iatrogenic complication of an overly aggressive lateral retinacular release. Noniatrogenic medial patellar dislocations are rare. The management of these injuries is not well described.Purpose:To describe the experience of the International Patellofemoral Study Group with patients with noniatrogenic medial patellar dislocation.Study Design:Case series; Level of evidence, 4.Methods:Members of the International Patellofemoral Study Group (N = 64) were surveyed between October 2018 and April 2019. This group was chosen because of its wide referral base and interest in patellar instability. Specialists who had encountered a patient with medial patellar instability were sent a questionnaire inquiring about details of the case, including patient demographics, medical history, level of athletic competition, injury characteristics, and treatment. Cases were confirmed by physical examination records and, in some cases, with findings on advanced radiographic imaging.Results:The survey response rate was 73% (47/64). Three of the 47 specialists (6.4%) reported they had seen a case of noniatrogenic medial patellar dislocation, for a total of 6 cases. Four cases were described as recurrent medial dislocations in the setting of hypermobile Ehlers-Danlos syndrome; 2 were treated nonoperatively, 1 underwent lateral patellofemoral ligament reconstruction, and 1 underwent derotational osteotomies. Two medial-sided patellar dislocations in collegiate athletes were sports-related injuries that required surgical debridement but no ligamentous reconstruction. None of the patients had persistent or recurrent instability at the time of their most recent follow-up.Conclusion:Noniatrogenic medial patellar dislocations are extremely rare. This case review suggests that the treatment of first-time medial patellar instability in patients without known risk factors should follow the same principles as the treatment of lateral instability with no known risk factors, which is nonoperative management. For patients with documented risk factors and recurrence, surgery to address the risk factors may be appropriate.

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Adolescent Medial Patellofemoral Ligament Reconstruction: A Comparison of the Use of Autograft Versus Allograft Hamstring

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967118774272 ◽

2018 ◽

Vol 6 (5) ◽

pp. 232596711877427 ◽

Cited By ~ 2

Author(s):

Nikhil Kumar ◽

Tracey P. Bastrom ◽

M. Morgan Dennis ◽

Andrew T. Pennock ◽

Eric W. Edmonds

Keyword(s):

Patellar Instability ◽

Ligament Reconstruction ◽

Medial Patellofemoral Ligament ◽

Cruciate Ligament ◽

Lateral Release ◽

Return To Sports ◽

Medial Patellofemoral Ligament Reconstruction ◽

Level Of Evidence ◽

Significant Difference

Background: Recurrent patellar instability is commonly treated with medial patellofemoral ligament reconstruction (MPFLR), and the use of allograft in anterior cruciate ligament reconstructions has demonstrated inferior outcomes. Purpose: To compare the outcomes of allografts versus autografts in adolescent MPFLR for patellar instability. Study Design: Cohort study; Level of evidence, 3. Methods: A retrospective chart review was completed on patients younger than 18 years who underwent MPFLR for recurrent instability after failed nonoperative management over an 8-year period with a minimum 2-year follow-up. Patients were divided into autograft or allograft hamstring cohorts for comparison. Primary outcome measures were return to normal activity, incidence of redislocation/subluxation, pain, stiffness, other complications, and Kujala scores. Statistical analysis using unpaired t tests was performed, with an alpha value set at P < .05. Results: After criteria were applied, 59 adolescents (36 allograft, 23 autograft; 38 girls, 21 boys) with a mean ± SD age of 15.2 ± 1.7 years and a mean follow-up of 4.1 ± 1.9 years (allograft, 3.3 ± 1.1 years; autograft, 5.7 ± 2.1 years; P ≤ .001) were included. Seven patients had concurrent osteotomies (3 allograft, 4 autograft), 11 patients had concurrent loose body removals (5 allograft, 6 autograft), and 9 patients had concurrent lateral release (7 allograft, 2 autograft). Between groups, no significant difference was found in change between preoperative and most recent follow-up (mean, 1.2 ± 2.1) or rate of return to sports (mean, 73.3%). In total, 9 surgeries failed (3 allograft, 6 autograft). For the surviving grafts, a statistical difference in mean Kujala scores at final follow-up was noted (allograft, 92.7; autograft, 97.4; P = .02). Conclusion: We identified no significant differences in return to activity, pain score changes, and incidences of failure between patients undergoing MPFLR with allograft versus autograft. Although teenagers with surviving autograft MPFLR reported statistically higher Kujala scores, the mean score difference of 5 points was not clinically significant. It appears that using allograft tendon instead of autograft tissue for MPFLR in this teenage population does not adversely affect long-term outcomes.

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How Reliable is the Radiographic Diagnosis of Mild Madelung Deformity?

Journal of Wrist Surgery ◽

10.1055/s-0037-1612636 ◽

2017 ◽

Vol 07 (03) ◽

pp. 227-231 ◽

Cited By ~ 3

Author(s):

Thierry Guitton ◽

David Ring ◽

Sebastian Farr ◽

Keyword(s):

Online Survey ◽

Interobserver Agreement ◽

Study Group ◽

Diagnostic Study ◽

Level Of Evidence ◽

Madelung Deformity ◽

The Mean ◽

Sensitivity Specificity ◽

Relationship Of ◽

The Relationship

Background Patients with Madelung deformity exhibit a spectrum of mild to severe deformity and distortion of wrist geometry. It may be difficult to reliably distinguish mild Madelung deformity from normal. Purpose This study thus tested the reliability of the diagnosis of mild Madelung deformity on a single posteroanterior (PA) radiograph. Materials and Methods An online survey was sent to hand and wrist surgeons of the Science of Variation Study Group for evaluation of 25 PA wrist radiographs comprising five adults with suspected mild Madelung deformity and 20 radiographs without any evident wrist pathology. Interobserver agreement was evaluated both via average percent agreement and Fleiss' kappa. To evaluate the relationship of rater characteristics and accuracy, a linear regression model was computed. Results The interobserver agreement among the 69 participating surgeons was low (Κ = 0.12). The overall sensitivity, specificity, and accuracy were 0.30, 0.86, and 0.75, respectively. The mean confidence was 7.4 ± 0.4 for mild Madelung and 7.8 ± 0.5 for normal (p = 0.112). The observers' confidence level was the only factor which had a mild but significant effect on the accuracy of the ratings. Conclusion The diagnosis of mild Madelung deformity on a single PA radiograph is unreliable. Level of Evidence The level of evidence is II, diagnostic study.

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A Delphi Study to Detect Deficiencies and Propose Actions in Real Life Treatment of Neovascular Age-Related Macular Degeneration

Journal of Ophthalmology ◽

10.1155/2014/595132 ◽

2014 ◽

Vol 2014 ◽

pp. 1-10 ◽

Cited By ~ 4

Author(s):

Alfredo García-Layana ◽

Luis Arias ◽

Marta S. Figueroa ◽

Javier Araiz ◽

José María Ruiz-Moreno ◽

...

Keyword(s):

Macular Degeneration ◽

Delphi Study ◽

Online Survey ◽

Real Life ◽

Age Related Macular Degeneration ◽

Modified Delphi ◽

Age Related ◽

Consensus Statements ◽

High Level ◽

Level Of Agreement

Purpose. Spanish retina specialists were surveyed in order to propose actions to decrease deficiencies in real-life neovascular age macular degeneration treatment (nv-AMD).Methods. One hundred experts, members of the Spanish Vitreoretinal Society (SERV), were invited to complete an online survey of 52 statements about nv-AMD management with a modified Delphi methodology. Four rounds were performed using a 5-point Linkert scale. Recommendations were developed after analyzing the differences between the results and the SERV guidelines recommendations.Results. Eighty-seven specialists completed all the Delphi rounds. Once major potential deficiencies in real-life nv-AMD treatment were identified, 15 recommendations were developed with a high level of agreement. Consensus statements to reduce the burden of the disease included the use of treat and extend regimen and to reduce the amount of diagnostic tests during the loading phase and training technical staff to perform these tests and reduce the time between relapse detection and reinjection, as well as establishing patient referral protocols to outside general ophthalmology clinics.Conclusion. The level of agreement with the final recommendations for nv-AMD treatment among Spanish retinal specialist was high indicating that some actions could be applied in order to reduce the deficiencies in real-life nv-AMD treatment.

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Patella dislocations and patellofemoral instability: a current concepts review

SA Orthopaedic Journal ◽

10.17159/2309-8309/2021/v20n3a6 ◽

2021 ◽

Vol 20 (3) ◽

Author(s):

Benjamin R Garrett ◽

Michael L Grundill

Keyword(s):

Patellar Dislocation ◽

Surgical Intervention ◽

Trochlear Dysplasia ◽

Patellofemoral Instability ◽

Tibial Tubercle ◽

First Episode ◽

Level Of Evidence ◽

Lateral Patellar Dislocation ◽

Consensus Statements ◽

Patella Dislocations

ABSTRACT Lateral patellar dislocation affects young, active patients with an incidence rate of 5.8 per 100 000. The management of first episode dislocations is non-surgical in the majority of cases, unless associated pathology dictates surgical intervention. Approximately 40% of cases that are treated non-surgically will develop recurrent patellofemoral instability. Evidence supports surgical intervention in these cases; however, the best approach is debatable. Most research and consensus statements agree that medial patellofemoral ligament reconstruction (MPFLR) should be performed in most cases. Additional procedures can be used 'a la carte' according to certain conditions or pathology. A tibial tubercle osteotomy (TTO) is usually indicated in patients with maltracking and/or patella alta, but the direction and degree of correction must be carefully considered. Trochleoplasty is technically demanding and should be reserved for a select few patients with severe trochlear dysplasia. It should be performed by an experienced knee surgeon due to the high risk of inadvertent complications. Level of evidence: Level 5 Keywords: patellofemoral instability, patellar dislocation

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Increased incidence of acute patellar dislocations and patellar instability surgical procedures across the United States in paediatric and adolescent patients

Journal of Children s Orthopaedics ◽

10.1302/1863-2548.15.200225 ◽

2021 ◽

Vol 15 (2) ◽

pp. 149-156

Author(s):

Kelly H. McFarlane ◽

Ryan P. Coene ◽

Lanna Feldman ◽

Patricia E. Miller ◽

Benton E. Heyworth ◽

...

Keyword(s):

United States ◽

Surgical Procedures ◽

Patellar Instability ◽

Patellofemoral Instability ◽

Sports Participation ◽

The United States ◽

Significant Rise ◽

Level Of Evidence ◽

Adolescent Patients ◽

Paediatric Orthopaedic

Purpose Patellofemoral instability is a common cause of knee pain and dysfunction in paediatric and adolescent patients. The purpose of the study was to evaluate the frequency of patellar dislocations seen in emergency departments (EDs) and the rates of surgical procedures for patellar instability at paediatric hospitals in the United States between 2004 and 2014. Methods The Pediatric Health Information System database was queried for all paediatric patients who underwent surgery for patellar instability or were seen in the ED for acute patellar dislocation between 2004 and 2014. This was compared with the annual numbers of overall orthopaedic surgical procedures. Results Between 2004 and 2014, there were 3481 patellar instability procedures and 447 285 overall orthopaedic surgical procedures performed at the included institutions, suggesting a rate of 7.8 per 1000 orthopaedic surgeries. An additional 5244 patellar dislocations treated in EDs were identified. Between 2004 and 2014, the number of patellar instability procedures increased 2.1-fold (95% confidence interval (CI) 1.4 to 3.0), while orthopaedic surgical procedures increased 1.7-fold (95% CI 1.3 to 2.0), suggesting a 1.2-fold relative increase in patellar instability procedures, compared with total paediatric orthopaedic surgeries. Conclusion This study shows a significant rise in the rate of acute patellar instability treatment events in paediatric and adolescent patients across the country. Surgery for patellar instability also increased over the study period, though only slightly more than the rate of all paediatric orthopaedic surgical procedures. This may suggest that increasing youth sports participation may be leading to a spectrum of increasing injuries and associated surgeries in children. Level of Evidence IV

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Lateral retinacular release combined with MPFL reconstruction for patellofemoral instability: a systematic review

Archives of Orthopaedic and Trauma Surgery ◽

10.1007/s00402-020-03689-9 ◽

2020 ◽

Author(s):

Filippo Migliorini ◽

Nicola Maffulli ◽

Jörg Eschweiler ◽

Valentin Quack ◽

Markus Tingart ◽

...

Keyword(s):

Systematic Review ◽

Patellofemoral Instability ◽

Mpfl Reconstruction ◽

Lateral Release ◽

Lateral Retinacular Release ◽

Level Of Evidence ◽

Lateral Retinaculum ◽

Reporting Data

Abstract Introduction The role of the lateral retinaculum in patellofemoral instability is still debated. Lateral retinacular release (LRR), has been extensively performed in combination with different surgical procedures, including reconstruction of medio-patellofemoral ligament (MPFL). Despite controversial indications, the results from these studies seem promising. The present study conducts a systematic review about current biomechanical and clinical evidence concerning the role of LRR in combination with MPFL reconstruction. We performed a comprehensive literature research, comparing the outcomes of MPFL reconstruction with and without LRR. Materials and methods This systematic review was conducted according to the PRISMA guidelines. The literature search was performed in August 2020. All articles describing the outcome of isolated MPFL reconstruction alone or in combination with a LRR in patients with recurrent patellofemoral instability were considered for inclusion. Only articles reporting data on patients with a minimum of 12-month follow-up were included. Only articles reporting quantitative data under the outcomes of interest were included. Results A total of 63 articles were eligible for this systematic review, including 2131 knees. The mean follow-up was 40.87 ± 24.1 months. All scores of interests improved in favour of the combined group: Kujala + 3.8% (P = 0.01), Lysholm + 4.2% (P = 0.004), Tegner + 0.8 points (P = 0.04), IKDC + 9.8% (P = 0.02). The ROM was comparable between the two groups (P = 0.4). Similarity was found in terms of positivity to the apprehension test (P = 0.05), rate of complications (P = 0.1), re-dislocations (P = 0.8), and revision surgeries (P = 0.1). Conclusion There is no evidence that adding a lateral release impacts positively on the outcome of MPFL reconstruction. Level of evidence: IV, Systematic review

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Distalization and Medialization of Tibial Tuberosity for the Treatment of Potential Patellar Instability with Patella Alta

Joints ◽

10.1055/s-0038-1661340 ◽

2018 ◽

Vol 06 (02) ◽

pp. 080-084 ◽

Cited By ~ 2

Author(s):

Davide Enea ◽

Pier Paolo Canè ◽

Marco Fravisini ◽

Antonio Gigante ◽

Luca Dei Giudici

Keyword(s):

Patellar Instability ◽

Patellofemoral Instability ◽

Tibial Tuberosity ◽

Patella Alta ◽

Functional Improvement ◽

Patella Dislocation ◽

Level Of Evidence ◽

Exact Test ◽

History Of ◽

Retrospective Comparative Study

Purpose The aim of the study was to test the distalization and medialization of the tibial tuberosity (DMTT) for the treatment of patellar instability associated with patella alta, focusing on residual instability and pain. Methods Twenty-four consecutive patients (26 knees) suffering from patellofemoral instability and patella alta were treated by DMTT. Two groups were identified, which differed for documented history of frank patella dislocation. The groups were named objective patellar instability (OPI) (history of dislocation) and potential patella instability (PPI) (no dislocation). Outcome was measured with visual analogue scale (VAS), Kujala score, and Tegner score. Comparison between groups was performed using Student's t-test, Wilcoxon rank score, and Fisher's exact test (significance at p < 0.05). Results At 50 ± 18 and 41 ± 18 months of follow-up, respectively, both PPI and OPI groups obtained a significant pain reduction and functional improvement. The PPI group showed a significant decrease of the subjective instability. No procedure-related complications were reported. Conclusion This study suggests that DMTT is a viable option for PPI patients with patella alta. The outcome was comparable between PPI and OPI cases; however, decrease in subjective instability was significantly greater in PPI patients. Level of Evidence Level III, retrospective comparative study.

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Conservative versus tailored surgical treatment in patients with first time lateral patella dislocation: a randomized-controlled trial

Journal of Orthopaedic Surgery and Research ◽

10.1186/s13018-021-02513-3 ◽

2021 ◽

Vol 16 (1) ◽

Author(s):

M. Liebensteiner ◽

A. Keiler ◽

R. El Attal ◽

P. Balcarek ◽

F. Dirisamer ◽

...

Keyword(s):

Randomized Controlled Trial ◽

Surgical Treatment ◽

Patellar Instability ◽

Controlled Trial ◽

Patellofemoral Instability ◽

Patella Dislocation ◽

Conservative Group ◽

Randomized Controlled ◽

First Time

Abstract Background Patellar instability has a high incidence and occurs particularly in young and female patients. If the patella dislocates for the first time, treatment is usually conservative. However, this cautious approach carries the risk of recurrence and of secondary pathologies such as osteochondral fractures. Moreover, there is also risk of continuous symptoms apparent, as recurrent patella dislocation is related to patellofemoral osteoarthritis as well. An initial surgical treatment could possibly avoid these consequences of recurrent patella dislocation. Methods A prospective, randomized-controlled trial design is applied. Patients with unilateral first-time patella dislocation will be considered for participation. Study participants will be randomized to either conservative treatment or to a tailored patella stabilizing treatment. In the conservative group, patients will use a knee brace and will be prescribed outpatient physical therapy. The surgical treatment will be performed in a tailored manner, addressing the pathologic anatomy that predisposes to patella dislocation. The Banff Patellofemoral Instability-Instrument 2.0, recurrence rate, apprehension test, joint degeneration, and the Patella Instability Severity Score will serve as outcome parameters. The main analysis will focus on the difference in change of the scores between the two groups within a 2-year follow-up. Statistical analysis will use linear mixed models. Power analysis was done for the comparison of the two study arms at 2-year follow-up with regard to the BPII Score. A sample size of N = 64 per study arm (128 overall) provides 80% power (alpha = 0.05, two-tailed) to detect a difference of 0.5 standard deviations in a t-test for independent samples. Discussion Although several studies have already dealt with this issue, there is still no consensus on the ideal treatment concept for primary patellar dislocation. Moreover, most of these studies show a unified surgical group, which means that all patients were treated with the same surgical procedure. This is regarded as a major limitation as surgical treatment of patella dislocation should depend on the patient’s anatomic pathologies leading to patellar instability. To our knowledge, this is the first study investigating whether patients with primary patella dislocation are better treated conservatively or operatively with tailored surgery to stabilize the patella. Trial registration The study will be prospectively registered in the publicly accessible database www.ClinicalTrials.gov.

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