Abstract
Background:
The medial patellofemoral ligament (MPFL) has been investigated widely in the past 30 years, resulting in many research achievements in this field.
Purpose:
To perform a comprehensive bibliometric analysis to evaluate the 100 top-cited articles on the MPFL.
Study Design:
Cross-sectional study.
Methods:
We searched the Scopus database in December 2022 using the terms “medial patellofemoral ligament” OR “MPFL.” The search was confined to English-language articles, including technical notes, systematic reviews on clinical outcomes and/or complications, clinical studies, studies regarding complications, and basic science articles (either cadaveric or biomechanical); we excluded letters, case reports, personal opinions, guidelines, editorials, and narrative or other types of reviews. Analysis of the 100 top-cited articles was performed according to total number of citations, average citations per year (ACY), study type, country of origin, journal of publication, affiliated institution, and most published authors.
Results:
The total number of citations was 16,358 (range of citations per article, 72-692). The majority of articles were published as clinical studies (54%), with cadaveric studies being the second most common (21%). Most studies originated in the United States (32%), with Japan (15%) and Germany (13%) following. The American Journal of Sports Medicine published the majority of the 100 top-cited articles (37/100; 6304 citations) as well as the 10 top-cited articles according to ACY (7/10; mean, 285.14 citations). The most prolific authors were Nomura (8 articles); Burks (6 articles); and Inoue, Sillanpää, and Dreyhaupt (5 articles each).
Conclusion:
By analyzing the characteristics of the 100 top-cited articles, this study demonstrated that the MPFL is a growing and popular area of research, with the focus varying through timeline trends. Questions regarding MPFL anatomy, isometry, and biomechanics might have been answered adequately, but research regarding optimal fixation technique under various circumstances is still ongoing.
Keywords
Patellar dislocation/instability is a common knee problem, affecting about 5.8 persons per 100,000 of the general population and 29 per 100,000 in the 10- to 17-year-old age-group.22,25 It accounts for 2% to 3% of all acute knee injuries. 62 The causes lie in osseous abnormalities, patellar alta, trochlea dysplasia, tibial tubercle-trochlea groove distance >20 mm, valgus malalignment, patellar tilt, and soft tissue laxity, usually due to medial patellofemoral ligament (MPFL) rupture or vastus medialis oblique (VMO) weakness.11,23 Numerous studies have proposed that MPFL reconstruction is superior to conservative management in terms of functional outcomes and recurrent episodes among patients with recurrent patellar instability.10,31,32,60 Although nonoperative treatment is primarily recommended for first-time dislocation, 44% to 70% of patients progress to recurrent dislocation and subsequent surgical management. 32 Newer studies, analyzing risk stratification models for recurrency after the first-time episode, have suggested surgical treatment for the high-risk groups only,10,31,71 while others have proposed MPFL reconstruction for all first-time dislocation.10,23 Palpable defects on VMO, adductor mechanism, or gross patellar dislocation constitute prognostic factors for recurrent episodes after first-time patellar dislocation. 26 Anterior knee pain with effusion on exertion, a persistent sensation of instability, a positive J-sign, and a positive patellar tilt test are also considered important clinical signs of MPFL insufficiency. 27
The first published article on the MPFL dates back to 1992 and is by Ellera Gomes et al, 19 reporting the first case series on MPFL reconstruction using a synthetic graft. Since then, numerous articles have been published regarding the anatomy, biomechanical properties, radiological landmarks, clinical results, and complications of MPFL reconstruction. Bibliometric analyses have been used to highlight consensus areas, controversial aspects, research frontiers, and centers as well as current trends on various topics to provide a comprehensive updated reference for the readers. Reviewing previous bibliometric articles on Scopus and PubMed, we found articles on anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) reconstruction and patellar instability,29,65,71 but no bibliometric articles were found on the MPFL.
As MPFL reconstruction has been an increasingly accepted procedure, we decided to identify the 100 most cited articles on the MPFL from 1992 onward and to describe the characteristics of these articles, providing a reference for better comprehension of research in this area and also highlighting potential directions for future research.
Methods
Data Collection and Allocation
We undertook a search of Scopus—one of the largest databases of qualified scientific articles that provides citation data—for our literature review. The terms used were “medial patellofemoral ligament” OR “MPFL” in all fields. The search was confined to English-language articles, without any timeframe restriction. We included technical notes, systematic reviews on clinical outcomes and/or complications, clinical studies, studies regarding complications, and basic science articles (either cadaveric or biomechanical), whereas letters, case reports, personal opinions, guidelines, editorials, and narrative or other types of review were excluded. Two authors (V.G. and A.P.) independently identified articles for inclusion to enhance sensitivity. The search was performed during December 2022 and yielded 2556 results, which included all articles published since 1992.
All articles were then ranked by the number of citations; after removing those with fewer than 70 citations, a total of 201 articles remained for analysis. After review of the title and abstract, each article was categorized based on study type into 7 categories: (1) cadaveric (anatomic and/or biomechanical), (2) clinical, (3) computational, (4) radiological, (5) technical, (6) complications, and (7) systematic reviews. After excluding nonrelevant articles and reaching a mutual decision on the controversial articles, a total of 102 articles remained. Then, after arranging them according to the number of citations, the top 100 most cited articles were ultimately included in the analysis (Figure 1).
Flowchart illustrating the article selection procedure for the top 100 most cited articles on the MPFL. MPFL, medial patellofemoral ligament.
Data Extraction
We used Bibliometrix R-package software (https://www.bibliometrix.org) for the data analysis. An Excel (2021; Microsoft Corp) file containing the article titles and citation number was extracted from Scopus on December 31, 2022, so as to establish data congruity during the study. The full text of all the selected articles was reviewed, and the following information extracted: title, author names, journal, publication year, total number of citations, average citations per year (ACY), geographic origin, primary institution involved, study type, level of evidence, and keywords. Statistical analysis and data visualization were held in R and RStudio, both well-known open-source statistical software products.
Results
Nature of Published Articles
The 100 most cited articles on the MPFL are listed in Appendix Table A1. Research on the MPFL is relatively new ground, as confirmed by the late publication date of the first article (1992, Ellera Gomes 19 ) and the small total number of articles during our extensive search (2556 results). For comparison, the term “ACL” in PubMed revealed more than 34,000 results. Most articles (73 of 100) appeared during the decade 2005 to 2015, as shown in Figure 2. The reduction in the number of top-cited articles from the most recent years is reflective of the type of analysis of top-cited articles and not of research trends. The total number of citations was 16,358 (range of citations per article, 72-692). Analysis per decade indicated that 9 of the articles were published between 1990 and 1999, 52 articles were published between 2000 and 2009, and 39 articles were published between 2010 and 2019, showing the growing research interest in the field.
Top 100 most cited articles on the MPFL per year of publication and the distribution of overall citations over time. MPFL, medial patellofemoral ligament.
Figure 3A shows the top 100 articles after being categorized by study type (clinical, cadaveric, radiological, complications, technical notes, reviews, and computational studies). Cadaveric studies were subcategorized as anatomic (33.3%), biomechanical (47.6%), and both (19%) (Figure 3B), whereas clinical studies were subcategorized as prospective (79.6%) and retrospective (Figure 3C). The majority of the articles were clinical studies (54%), with cadaveric being the second most popular (21%).
(A) Categorization of the top 100 most cited articles on the MPFL by study type. Subcategorization of (B) cadaveric studies and (C) clinical studies. MPFL, medial patellofemoral ligament.
Source Analysis
An analysis of articles per country was performed. The United States was the most common country of publication (32%), with Japan (15%) and Germany (13%) also showing good contribution rates (Figure 4).
Country of origin of the 100 most cited articles on the MPFL. MPFL, medial patellofemoral ligament.
Regarding the affiliated institutions, Kawasaki Municipal Hospital in Japan had the largest number of top-cited articles (7 articles) and the most related citations (1224 total citations). Tampere University Hospital, Aarhus University Hospital and Imperial College were also in the top 10 institutions in both respects (Figure 5). Articles and citations per journal were also analyzed, with the top 5 journals being the same in both categories: American Journal of Sports Medicine (37 articles and 6304 citations), Knee Surgery, Sports Traumatology, Arthroscopy (20 articles), Arthroscopy (11 articles), Knee (7 articles) and Clinical Orthopedics and Related Research (4 articles) (Figure 6). The top 25 authors were extracted, with Nomura having the most articles in the top 100 with 8 articles. Burks (6 articles) and Inoue, Sillanpää, and Dreyhaupt (5 articles each) completed the top 5 authors (Figure 7).
(A) Top 100 most cited articles on the MPFL according to affiliated institution. (B) Ranking of institutions in (A) according to number of related citations. MPFL, medial patellofemoral ligament.
(A) Top 100 most cited articles on the MPFL according to journal of publication. (B) Ranking of journals in (A) according to number of related citations. MPFL, medial patellofemoral ligament.
Top 25 authors among the top 100 most cited articles on the MPFL according to number of articles per author. MPFL, medial patellofemoral ligament.
Characteristics of the Top 10 Most Cited Articles
The top 10 most cited articles by ACY are listed in Table 1. The number of ACY ranged from 30.30 to 17.77. Most of these articles (n = 7) were published in the American Journal of Sports Medicine, and the mean number of total citations was 340.3. Five articles were published in or before 2008 and 5 in or after 2012. The top 3 articles with most overall citations (>500) were all anatomic/biomechanical studies. Desio et al, 15 with 692 citations (ACY, 28.8), found that the MPFL is the primary restraint to lateral patellar translation at 20° of flexion, contributing 60% of the total restraining force. Conlan et al, 12 with 595 citations (ACY, 20.51), also confirmed that MPFL is a major medial soft tissue restraint, contributing an average of 53% of the total force, with an average of 22% rendered to the patellomeniscal ligament. Amis et al, 2 with 522 citations (ACY, 27.47), described the anatomy of the MPFL in detail, highlighted the length change pattern of the MPFL as the knee flexes, and noted that, if the MPFL is to be reconstructed, the femoral medial epicondyle is an adequate landmark.
Top 10 Articles According to ACY a
Average citations per year.
Journal titles abbreviated according to the format in PubMed.
The article with the best ACY (30.30) and 303 overall citations was a systematic review published in 2012 by Shah et al, 58 who reported a complication rate of 26.1% after MPFL reconstruction. In fourth place of the 10 most cited articles was the cadaveric/radiological study of Schöttle et al, 56 with 412 citations (ACY, 27.46), which was the first study to indicate a reproducible anatomic and radiographic point for proper intra- and postoperative control for the insertion of the reconstructed MPFL (1 mm anterior to the posterior cortex extension line, 2.5 mm distal to the posterior origin of the medial femoral condyle, and proximal to the level of the posterior point of the Blumensaat line on a lateral radiograph with both posterior condyles projected in the same plane). The 5 remaining ACY top 10 articles discussed patellar instability factors in isolated MPFL reconstruction, 67 clinical outcomes after isolated MPFL reconstruction, 54 predictors of recurrent instability after acute dislocation in pediatric and adolescent patients, 30 management of acute patellar dislocation in children and adolescents, 40 and, finally, complications of MPFL reconstruction in young patients. 44
Discussion
The research potential on the MPFL should be considered high if we take into account recent advancements in its research (1992 and onward), as the top 100 MPFL citations (16,358) were more than those of the 50 top-cited PCL (7908; 1975 and onward) 29 and nearly half of the 100 most cited ACL articles (29,629; 1975 and onward). 65 The American Journal of Sports Medicine was again the journal with the most cited articles, as noted in the ACL and PCL bibliometric studies.29,65 The United States plays a leading role in MPFL research, with Germany and Japan also holding an important role. After reviewing the latest articles, we were able to ascertain that the main controversies on MPFL anatomy, attachments, function, insertion point, and isometry have been answered to a large extent, and research nowadays focuses on the best reconstruction techniques, clinical outcomes, complications, and concomitant procedures in cases of dysplasia and other skeletal abnormalities. Our world cloud analysis contained keywords such as adolescent, child, recurrence, treatment, outcome, and biomechanics, with bold font showing where research is concentrated today. A comprehensive summary of the most important issues on the MPFL is provided below.
Anatomy and Biomechanics
In our bibliometric review of the 100 most cited papers, 21 papers studied MPFL anatomy and biomechanical properties. A wide agreement regarding MPFL femoral and patellar attachments was identified. In 2003, Smirk and Morris 59 concluded that the MPFL attaches to the superomedial patella and on the femur 10 mm distal and 5 mm posterior to the adductor tubercle. In 2005, Nomura et al 39 found also a superior patellar insertion and a femoral attachment just distal to the adductor tubercle, whereas they reported a wispy MPFL in 3 of 20 knees dissected. In 2009, Baldwin 3 identified 2 femoral origins for the MPFL, a transverse 10.6-mm attachment on the bony groove between the medial epicondyle and adductor tubercle and an oblique decussation originating from the proximal 30 mm of the leading edge of the superficial MCL. This conclusion had also been reached by Feller et al 21 in 1993, who identified the MPFL and VMO blending as well as the positioning of the MPFL in layer 2. In 2009, Philippot et al 46 measured the MPFL to VMO junction at 25.7 ± 6 mm and identified an anatomic femoral attachment of the MPFL at 10 mm posterior to the medial epicondyle and 10 mm distal to the adductor tubercle. In 2002, Tuxøe et al 68 suggested following the VMO fibers, adductor longus tendon, and superior edge of the MPFL to successfully identify the MPFL in layer 2, as the inferior edge of the MPFL can be challenging to identify. In 2014, Stephen et al 64 also identified the anatomic femoral attachment as equidistant along the line connecting the medial epicondyle to the adductor tubercle. They used a radiological rule of 40% from the posterior, 50% from the distal and 60% from the anterior outline, provided that anteroposterior size is 100%. Finally, in 2010, Kang et al 28 identified 2 MPFL bundles: an inferior straight bundle being the main static soft tissue restraint to lateral patella displacement and a superior oblique bundle providing dynamic stability in conjunction with VMO. We see a consensus regarding femoral attachment of the MPFL just distal to the adductor tubercle and superomedial patellar attachment.
Contribution to Lateral Patellar Displacement
A number of articles studied the contribution of the MPFL, medial retinaculum (MR), medial patellomeniscal ligament (MPML), and medial patellotibial ligament (MPTL) to lateral patellar displacement (LPD). In 1998, Desio et al, 15 cited by 692 articles (the most cited article on the MPFL), tested medial and lateral restraint to LPD at 20° of flexion, suggesting 60% contribution for the MPFL, 13% for the MPML, and 10% for the lateral retinaculum (LR) and a not measurable contribution for the MPTL and MR. Hautamaa et al, 24 Nomura et al, 38 and Sandmeier et al 52 reached a similar conclusion, ie, that the MPFL is the major stabilizer of LPD and can restore normal kinematics after its reconstruction, especially at 20° to 90° of flexion. Panagiotopoulos et al 41 suggested 50% MPFL contribution to medial stability, 24% MPML, and 13% each for MPTL and MR, whereas VMO and MPFL meshing increases the MPFL percentage to more than 50%. Finally, in 2012, Philippot et al 45 also measured MPFL contribution to LPD and lateral tilt reduction at 50% to 60% and suggested that MPFL reconstruction is performed at 20° to 30° of flexion.
Isometry
Stephen et al 64 tested 3 superomedial patellar attachments and 5 femoral attachments, suggesting that the anatomic femoral position (at the midpoint between the medial epicondyle and the adductor tubercle) was the most isometric with a mean length increase of 2.1 mm, whereas attachment 5 mm proximal and 5 mm distal increased MPFL length by 6.4 mm and 9.1 mm, respectively. Steensen et al 61 agreed with a previous finding that the correct femoral attachment is the most important parameter for MPFL isometry. Victor et al 69 found the MPFL to be nonisometric, suggesting that, although the middle part of the MPFL is isometric, the cranial part is most taut at full extension and the caudal part at 30°, interpreting the 2-bundle theory of Kang et al 28 differently. A computational study by Elias and Cosgarea 18 revealed an increase in medial pressure at 30° of flexion either by proximal femoral graft malposition or by reduced graft resting length, whereas both scenarios increased medial pressure significantly at 30° to 90° of flexion. Beck et al 4 examined the graft tensioning force and found that 2 N restored normal translation but that higher forces increased medial pressure and restricted motion. A more recent study by Stephen et al 64 also concluded that 2 N restores joint contact pressures, proposing an anatomic femoral fixation with 2 N at 30° or 60° of flexion. Finally, Mountney et al 33 examined the force to failure of native MPFL, suture-only repair, bone anchors plus suture, blind-tunnel tendon graft and through-tunnel tendon graft, measuring 208, 37, 142, 126, and 195 N, respectively, and found no statistical difference between native MPFL and blind tunnel graft.
Clinical Results
Ellera Gomes 19 , with 186 citations, was the first to describe a technique of MPFL reconstruction, presenting a series of 30 patients with 83% showing significant improvement after an average follow-up of 39 months. Sallay et al 50 , with 417 citations to date, performed a pathoanatomic correlation study and presented a case series of 11 MPFL repairs, with 58% of the patients showing excellent-to-good results according to Lysholm score and return-to-play data. Nomura 36 , with 229 citations, classified MPFL injuries intraoperatively, with most knees presenting with scar tissue along the MPFL course. Schöttle et al 55 , being in the top 10 most cited articles with 281 citations, presented in 2005 a technique of MPFL reconstruction utilizing a semitendinosus autograft fixed with 2 sutures anchors at the superomedial border of the patella and tendon to bone tunnel fixation by an interference screw at the adductor tubercle.
Since then, numerous top-cited articles presented very good to excellent results after MPFL reconstruction with various techniques for recurrent patellar dislocation in adults.1,5,7,8,13,16,20,37,63 Limited results, however, were reported among subjects with high tibial tubercle-trochlear groove distance, severe trochlear dysplasia, failure to repair VMO, and children and adolescents presenting with first-time patellar dislocation.9,14,30,40,70 The majority of the rest of the clinical studies in the top 100 most cited MPFL articles showed good clinical results and low rates of redislocation after MPFL reconstruction.
Worth noting is the dynamic MPFL reconstruction technique proposed by Panagopoulos et al, 42 where the semitendinosus tendon, being attached to its insertion, is rerouted though the adductor magnus pulley and fixed to the superomedial patella at 60° of flexion. Remarkable also are the clinical results of the divergent patellar transverse 2-tunnel technique with autologous semitendinosus graft reported by Panni et al, 43 demonstrating 80% patient satisfaction and a low rate of redislocation. A biomechanical study by Mountney et al 33 has also shown the superiority of the through tunnel technique; however, the incidence of patellar fracture, as noted by Panni et al, 43 is a subject still studied today.47,48 An article by Thaunat and Erasmus 66 suggested that every patella fits its own trochlea and therefore MPFL reconstruction can be an isolated procedure, aiming at a favorable anisometry, with isometry gained at full extension. For children and adolescents with open femoral physes, primary MPFL repair, anatomic reconstruction with respect to the femoral physes, and dynamic reconstruction with the medial collateral ligament acting as a pulley have shown good results in the current pool of studies.13,14,35,40 To conclude, MPFL reconstruction was found to be an effective procedure for recurrent patellar dislocation, in terms of postoperative dislocation and functional scores, in isolation or combined with additional procedures when so indicated.
Radiological Results
The top-cited radiological study in our review, with 412 citations, was that of Schöttle et al 56 in 2007 defining the radiological femoral attachment of the MPFL as previous mentioned. In 2010, Redfern et al 49 proposed another reproducible radiographic landmark for femoral MPFL insertion as 0.5 mm anterior to the distal posterior cortex and just 3 mm proximal to the apex where it meets the Blumensaat line. Elias et al 17 and Sanders et al 51 showed that lateral patellar dislocation is accompanied by medial retinaculum, MPFL, and VMO injury, accurately identified by magnetic resonance imaging (MRI). Seeley et al 57 studied the MRI injury patterns after acute patellar dislocation among children, recognizing MPFL, VMO, and chondral injuries, and Nelitz et al 34 suggested that the femoral insertion of the MPFL in children is distal to the physis, so as to avoid tightening of the MPFL in knee flexion.
Complications
Two articles describing complications after MPFL reconstruction are among the top 10 articles with the best ACY. Shah et al 58 (ACY, 30.30) performed a systematic review in 2012 regarding complication rates after MPFL reconstruction; 25 articles were identified and reviewed, with the authors reporting a total of 164 complications occurring in 629 knees (26.1%). These adverse events included patellar fracture, failures, clinical instability, loss of knee flexion, wound complications, and pain. A trend of more overall complications was observed utilizing the tunnel techniques (29.8%) compared with suture techniques (21.6%). However, the suture techniques demonstrated a higher rate of recurrent dislocation/subluxation (4.8%) and apprehension/hypermobility (24.0%) than the tunnel technique (3.3% and 8.6%, respectively). Parikh et al 44 (ACY, 17.77) performed a retrospective clinical study in 2013, evaluating 179 knees that underwent MPFL reconstruction and found an incidence of complications (34 major and 4 minor) of 16.2%. Major complications included recurrent lateral patellar instability (23.5% of patients), knee motion stiffness with flexion deficits (23.5%), patellar fractures (17.6%), and patellofemoral arthrosis/pain (14.7%). Female sex and bilateral MPFL reconstructions were significant risk factors, whereas 47% of the complications were secondary to technical factors and were considered preventable. Bollier et al 6 highlighted the importance of femoral tunnel mispositioning in MPFL reconstruction, presenting a series of 5 patients who underwent revision surgery, and, in a series of 211 patients, Sapey-Marinier et al 53 reported 10 failures (4.7%) requiring surgical revision and also identified that patella alta and positive J-sign are the 2 major preoperative risk factors for failure.
Limitations
Only articles published in English were included in our research; thus, high-quality articles in other languages might have been omitted. In addition, only the Scopus database was utilized for data collection, as it is considered highly accurate and extensive and we were able to export citation data; other databases such as PubMed or Cochrane library were not included. Finally, the last limitation is inherent to the bibliometric research type, as the included articles might not reflect the current standard of care and evidence. However, this bibliometric study of the 100 top-cited papers on the MPFL provides a good base from which to identify research trends on the MPFL and hotspot research centers and provide some reading material for new residents and researchers to study the most influential papers on the MPFL and build on them with the current bibliography.
Conclusion
By analyzing the characteristics of the 100 top-cited articles, this study demonstrated that the MPFL is a growing and popular area of research, with the focus varying through timeline trends. Questions regarding native MPFL anatomy, isometry, and biomechanics might have been answered adequately, but research regarding optimal fixation technique under various circumstances is still ongoing.
Footnotes
Appendix
List of 100 Top-Cited Articles on the MPFL a
| No. | Authors | Year | Title | Journal b | No. of Citations |
|---|---|---|---|---|---|
| 1 | Desio SM, Burks RT, Bachus KN | 1998 | Soft tissue restraints to lateral patellar translation in the human knee | Am J Sports Med | 692 |
| 2 | Conlan T, Garth WP Jr, Lemons JE | 1993 | Evaluation of the medial soft-tissue restraints of the extensor mechanism of the knee | J Bone Joint Surg Am | 595 |
| 3 | Amis AA, Firer P, Mountney J, Senavongse W, Thomas NP | 2003 | Anatomy and biomechanics of the medial patellofemoral ligament | Knee | 522 |
| 4 | Sallay PI, Poggi J, Speer KP, Garrett WE | 1996 | Acute dislocation of the patella: a correlative pathoanatomic study | Am J Sports Med | 417 |
| 5 | Hautamaa PV, Fithian DC, Kaufman KR, Daniel DM, Pohlmeyer AM | 1998 | Medial soft tissue restraints in lateral patellar instability and repair | Clin Orthop Relat Res | 416 |
| 6 | Schöttle PB, Schmeling A, Rosenstiel N, Weiler A | 2007 | Radiographic landmarks for femoral tunnel placement in medial patellofemoral ligament reconstruction | Am J Sports Med | 412 |
| 7 | Shah JN, Howard JS, Flanigan DC, Brophy RH, Carey JL, Lattermann C | 2012 | A systematic review of complications and failures associated with medial patellofemoral ligament reconstruction for recurrent patellar dislocation | Am J Sports Med | 303 |
| 8 | Elias DA, White LM, Fithian DC | 2002 | Acute lateral patellar dislocation at MR imaging: injury patterns of medial patellar soft-tissue restraints and osteochondral injuries of the inferomedial patella | Radiology | 299 |
| 9 | Palmu S, Kallio PE, Donell ST, Helenius I, Nietosvaara Y | 2008 | Acute patellar dislocation in children and adolescents: a randomized clinical trial | J Bone Joint Surg Am | 290 |
| 10 | Schöttle PB, Fucentese SF, Romero J | 2005 | Clinical and radiological outcome of medial patellofemoral ligament reconstruction with a semitendinosus autograft for patella instability | Knee Surg Sports Traumatol Arthrosc | 281 |
| 11 | Smirk C, Morris H | 2003 | The anatomy and reconstruction of the medial patellofemoral ligament | Knee | 267 |
| 12 | Elias JJ, Cosgarea AJ | 2006 | Technical errors during medial patellofemoral ligament reconstruction could overload medial patellofemoral cartilage: a computational analysis | Am J Sports Med | 265 |
| 13 | Drez D Jr, Edwards TB, Williams CS | 2001 | Results of medial patellofemoral ligament reconstruction in the treatment of patellar dislocation | Arthroscopy | 252 |
| 14 | Mountney J, Senavongse W, Amis AA, Thomas NP | 2005 | Tensile strength of the medial patellofemoral ligament before and after repair or reconstruction | J Bone Joint Surg Br | 245 |
| 15 | Steiner TM, Torga-Spak R, Teitge RA | 2006 | Medial patellofemoral ligament reconstruction in patients with lateral patellar instability and trochlear dysplasia | Am J Sports Med | 234 |
| 16 | Nomura E | 1999 | Classification of lesions of the medial patello-femoral ligament in patellar dislocation | Int Orthop | 229 |
| 17 | Steensen RN, Dopirak RM, McDonald WG III | 2004 | The anatomy and isometry of the medial patellofemoral ligament: implications for reconstruction | Am J Sports Med | 225 |
| 18 | Nomura E, Inoue M, Osada N | 2005 | Anatomical analysis of the medial patellofemoral ligament of the knee, especially the femoral attachment | Knee Surg Sports Traumatol Arthrosc | 224 |
| 19 | Christiansen SE, Jacobsen BW, Lund B, Lind M | 2008 | Reconstruction of the medial patellofemoral ligament with gracilis tendon autograft in transverse patellar drill holes | Arthroscopy | 208 |
| 20 | Lewallen LW, McIntosh AL, Dahm DL | 2013 | Predictors of recurrent instability after acute patellofemoral dislocation in pediatric and adolescent patients | Am J Sports Med | 202 |
| 21 | Nomura E, Horiuchi Y, Kihara M | 2000 | Medial patellofemoral ligament restraint in lateral patellar translation and reconstruction | Knee | 201 |
| 22 | Bicos J, Fulkerson JP, Amis A | 2007 | Current concepts review: the medial patellofemoral ligament | Am J Sports Med | 188 |
| 23 | Ahmad CS, Stein BES, Matuz D, Henry JH | 2000 | Immediate surgical repair of the medial patellar stabilizers for acute patellar dislocation: a review of eight cases | Am J Sports Med | 188 |
| 24 | Ellera Gomes JL | 1992 | Medial patellofemoral ligament reconstruction for recurrent dislocation of the patella: a preliminary report | Arthroscopy | 186 |
| 25 | Deie M, Ochi M, Sumen Y, Yasumoto M, Kobayashi K, Kimura H | 2003 | Reconstruction of the medial patellofemoral ligament for the treatment of habitual or recurrent dislocation of the patella in children | J Bone Joint Surg Br | 182 |
| 26 | Panagiotopoulos E, Strzelczyk P, Herrmann M, Scuderi G | 2006 | Cadaveric study on static medial patellar stabilizers: the dynamizing role of the vastus medialis obliquus on medial patellofemoral ligament | Knee Surg Sports Traumatol Arthrosc | 181 |
| 27 | Christiansen SE, Jakobsen BW, Lund B, Lind M | 2008 | Isolated repair of the medial patellofemoral ligament in primary dislocation of the patella: a prospective randomized study | Arthroscopy | 178 |
| 28 | Ellera Gomes JL, Stigler Marczyk LR, De César PC, Jungblut CF | 2004 | Medial patellofemoral ligament reconstruction with semitendinosus autograft for chronic patellar instability: a follow-up study | Arthroscopy | 178 |
| 29 | Deie M, Ochi M, Sumen Y, Adachi N, Kobayashi K, Yasumoto M | 2005 | A long-term follow-up study after medial patellofemoral ligament reconstruction using the transferred semitendinosus tendon for patellar dislocation | Knee Surg Sports Traumatol Arthrosc | 177 |
| 30 | Tuxøe JI, Teir M, Winge S, Nielsen PL | 2002 | The medial patellofemoral ligament: a dissection study | Knee Surg Sports Traumatol Arthrosc | 174 |
| 31 | Sillanpää P, Mattila VM, Iivonen T, Visuri T, Pihlajamäki H | 2008 | Incidence and risk factors of acute traumatic primary patellar dislocation | Med Sci Sports Exerc | 171 |
| 32 | Nomura E, Horiuchi Y, Kihara M | 2000 | A mid-term follow-up of medial patellofemoral ligament reconstruction using an artificial ligament for recurrent patellar dislocation | Knee | 170 |
| 33 | Parikh SN, Nathan ST, Wall EJ, Eismann EA | 2013 | Complications of medial patellofemoral ligament reconstruction in young patients | Am J Sports Med | 160 |
| 34 | Wagner D, Pfalzer F, Hingelbaum S, Huth J, Mauch F, Bauer G | 2013 | The influence of risk factors on clinical outcomes following anatomical medial patellofemoral ligament (MPFL) reconstruction using the gracilis tendon | Knee Surg Sports Traumatol Arthrosc | 158 |
| 35 | Bitar AC, Demange MK, D’Elia CO, Camanho GL | 2012 | Traumatic patellar dislocation: nonoperative treatment compared with MPFL reconstruction using patellar tendon | Am J Sports Med | 158 |
| 36 | Camanho GL, Viegas Ade C, Bitar AC, Demange MK, Hernandez AJ | 2009 | Conservative versus surgical treatment for repair of the medial patellofemoral ligament in acute dislocations of the patella | Arthroscopy | 153 |
| 37 | Sanders TG, Morrison WB, Singleton BA, Miller MD, Cornum KG | 2001 | Medial patellofemoral ligament injury following acute transient dislocation of the patella: MR findings with surgical correlation in 14 patients | J Comput Assist Tomogr | 153 |
| 38 | Schneider DK, Grawe B, Magnussen RA, Ceasar A, Parikh SN, Wall EJ, Colosimo AJ, Kaeding CC, Myer GD | 2016 | Outcomes after isolated medial patellofemoral ligament reconstruction for the treatment of recurrent lateral patellar dislocations: a systematic review and meta-analysis | Am J Sports Med | 150 |
| 39 | Nomura E, Horiuchi Y, Inoue M | 2002 | Correlation of MR imaging findings and open exploration of medial patellofemoral ligament injuries in acute patellar dislocations | Knee | 150 |
| 40 | Burks RT, Desio SM, Bachus KN, Tyson L, Springer K | 1998 | Biomechanical evaluation of lateral patellar dislocations | Am J Knee Surg | 149 |
| 41 | Buchner M, Baudendistel B, Sabo D, Schmitt H | 2005 | Acute traumatic primary patellar dislocation: long-term results comparing conservative and surgical treatment | Clin J Sport Med | 146 |
| 42 | Nelitz M, Dreyhaupt J, Reichel H, Woelfle J, Lippacher S | 2013 | Anatomic reconstruction of the medial patellofemoral ligament in children and adolescents with open growth plates: surgical technique and clinical outcome | Am J Sports Med | 140 |
| 43 | Ronga M, Oliva F, Longo UG, Testa V, Capasso G, Maffulli N | 2009 | Isolated medial patellofemoral ligament reconstruction for recurrent patellar dislocation | Am J Sports Med | 138 |
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MPFL, medial patellofemoral ligament.
Journal titles are abbreviated according to the format in PubMed.
Final revision submitted June 3, 2023; accepted August 10, 2023.
The authors have declared that there are no conflicts of interest in the authorship and publication of this contribution. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.
Ethical approval was not sought for the present study.