Original Article
Indications for Medial Patellofemoral Ligament Reconstruction: A Systematic Review Marco Yeung, MD1 Marie-Claude Leblanc, MD, FRCS(C)1 Olufemi R. Ayeni, MD, MSc, FRCS(C)1 Moin Khan, MD, MSc, FRCS(C)1 Laurie A. Hiemstra, MD, PhD, FRCS(C)2,3 Sarah Kerslake, MSc, BPhty2,4 Devin Peterson, MD, FRCS(C)1 1 Department of Surgery, McMaster University, Hamilton, Ontario, Canada 2 Banff Sport Medicine, Banff, Alberta, Canada 3 Department of Surgery, University of Calgary, Calgary, Alberta, Canada 4 Department of Physical Therapy, University of Alberta, Edmonton,
Address for correspondence Devin Peterson, MD, FRCS(C), Department of Orthopaedic Surgery, McMaster University, Suite 4E11, 1200 Main Street West, Hamilton, Ontario L8N 3Z5, Canada (e-mail:
[email protected]).
Alberta, Canada J Knee Surg
Abstract
Keywords
► medial patellofemoral ligament (MPFL) ► patellofemoral instability ► patellofemoral dislocation
The medial patellofemoral ligament (MPFL) plays a key role in lateral patellofemoral stability, and there has been significant clinical and research interest in MPFL reconstruction (MPFLR) in recent years. The primary objective of this systematic review of clinical studies is to investigate the reported indications for an isolated MPFLR and secondarily to examine some of the reasons reported for not performing an isolated MPFLR. A comprehensive search of the MEDLINE, EMBASE, PUBMED, and Cochrane databases was conducted to identify surgical studies investigating MPFLR. Study information including author, publication date, sample size, patient age, follow-up period, procedure performed, surgical indications and contraindications, and study design were extracted. The most common indication for isolated MPFLR was recurrent patellofemoral instability (82.1%). Common reasons given for not performing an isolated MPFLR included bony malalignment (51.8%), trochlear dysplasia (30.4%), and patella alta (23.2%). This systematic review identified recurrent patellofemoral instability as the primary indication for an isolated MPFLR; however, a large number of the studies did not provide clear criteria for when an isolated MPFLR should be performed. Similarly, there was significant variability in the reasons given for not performing an isolated MPFLR.
Patellofemoral instability is reported as the second most common cause of traumatic knee hemarthrosis1 and is commonly seen in young, active patients.2,3 Complications following a primary patellofemoral dislocation include redislocation (15–49%1,3–9), patellofemoral pain,3,10 and patellofemoral osteoarthritis.3,10 Subjective complaints of giving way, instability, decreased physical activity, diminished function, and reduced quality of life have also been described.1,2,9,11 Furthermore, studies have shown that up to 55% of patients are unable to return to their previous level of physical activity.7,8 A long-term study by Cofield and
Bryan reported on 48 acute primary dislocations treated conservatively and followed for an average of 11 years.12 Only 25% of patients reported being asymptomatic, with the remaining patients having complaints ranging from a conscious limitation of their activities to avoiding all vigorous sports. In 1997, Mäenpää et al reported results of a longterm study (13-year mean follow-up) on conservative treatment of acute patellar dislocation.9 In 25% of cases, retropatellar crepitation was observed during physical examination, which was interpreted as a sign of cartilaginous degeneration.
received March 1, 2015 accepted after revision August 23, 2015
Copyright © by Thieme Medical Publishers, Inc., 333 Seventh Avenue, New York, NY 10001, USA. Tel: +1(212) 584-4662.
DOI http://dx.doi.org/ 10.1055/s-0035-1564730. ISSN 1538-8506.
Indications for MPFL Reconstruction
Yeung et al.
Recurrent patellofemoral dislocation is also a very complex problem with significant consequences including patellofemoral pain, patellofemoral osteoarthritis, decreased functional ability, and reduced quality of life.1,3,4,8–11 The reported recurrence rate rises after recurrent dislocation,4–6,8 with greater than 50% of patients reporting persistent instability symptoms.1 Several studies have also demonstrated that greater than 50% of patients are dissatisfied following nonoperative treatment.3,4,10,12 Nomura and Inoue conducted an arthroscopic study on 60 knees, confirming chondral damage following acute patellar dislocation (30 patients) and recurrent patellar instability (30 patients).13 During the initial arthroscopy, 97% of patients in both cohorts demonstrated chondral damage of the patella. The trochlea was noted to be normal in 100% of the acute group, but only 90% of the recurrent group had a normal trochlea. The medial patellofemoral ligament (MPFL) plays a critical role in medial constraint for lateral patellofemoral stability, providing 50 to 60% of the soft tissue restraint prior to patellar engagement in the trochlear groove.2,4–6,14,15 MPFL insufficiency is present in as many as 90% of acute patellar dislocations and up to 100% of recurrent cases.3,15 Surgical stabilization has become an important and accepted modality in the management of patients with recurrent patellofemoral dislocation. Addressing MPFL insufficiency is a key component in the treatment algorithm of these individuals.6,14,15 In 1992, Ellera Gomes first described anatomical MPFL reconstruction (MPFLR) for recurrent patellar dislocation.16 In recent years, stabilization of the patellofemoral joint by addressing the medial soft tissue insufficiency through MPFLR has become a popular procedure, and studies have shown very high success rates.17–19 One large single-center study of 193 patients with recurrent patellar instability treated with isolated MPFLR showed significant improvement in pre- and postoperative outcomes scores, with no recurrence of instability.18 The popularity of MPFLR and the number of described techniques have increased exponentially; however, no single “gold standard” procedure has been established.15 Another significant challenge of assessing the number of studies on MPFLR is the lack of consensus in the literature regarding the appropriate surgical indications for MPFLR, and no review to date has fully documented the spectrum of indications applied in clinical practice. The primary purpose of this systematic review of patellofemoral instability clinical studies is to investigate the reported indications for an isolated MPFLR. Second, this review will examine some of the reasons reported for not performing an isolated MPFLR.
Methods Inclusion Criteria The inclusion criteria for this systematic review were as follows: (1) studies of human patients including all ages and both sexes, (2) clinical studies investigating the procedure of MPFLR either alone or associated with arthroscopic debridement and/or lateral release, and (3) studies published The Journal of Knee Surgery
in English. Exclusion criteria were (1) review articles, (2) diagnostic studies, (3) case reports and studies with fewer than five patients, (4) studies involving MPFLR with concurrent MPFL repair, osteotomies, or trochleoplasties, and (5) studies investigating only skeletally immature patients. For simplicity, the term isolated MPFLR will be used throughout the remainder of this article to describe studies that performed MPFLR with or without arthroscopic debridement and/or lateral release, but excluded MPFL repair, osteotomies, or trochleoplasties. A title and abstract review to screen for eligible studies was completed in duplicate. A full-text review was then conducted, also in duplicate, and references were hand searched for other eligible studies. Any discrepancies regarding inclusion were resolved through discussion and consensus between reviewers (M. Y. and M. K.).
Search Strategy Electronic databases (MEDLINE, EMBASE, PubMed, and Cochrane Library) were searched for MPFL studies from January 2000 to late April 2014. Given the rapid advancement of surgical techniques, the search was limited to the year 2000 to maintain surgical relevance. The search strategy used the following search terms: (1) “MPFL” or “medial patellofemoral ligament,” or “patellofemoral ligament” AND (2) “reconstruction,” “surgical operation,” or “surgery.” The Surgical Procedures, Operative (MeSH) subheading was also included in the MEDLINE search, and surgery, orthopedic surgery, and surgical technique subheadings were included in the EMBASE search. The results were uploaded to a bibliographic management database (RefWorks, version 2.0; Bethesda, MD).
Data Collection Data were collected from the included studies by two reviewers (M. Y. and M.-C. L.). Abstracted information included the following data: title, author, year of publication, location of study, sample size of isolated MPFLRs, number of male and female patients, mean age, length of follow-up, level of evidence, technique of intervention studied, surgical indications, and reasons for study exclusion of an isolated MPFLR.
Data Analysis All data abstracted from eligible studies were organized into a table (Microsoft Excel, Santa Rosa, CA). Descriptive statistics were calculated to reflect the frequency of outcome measures. Study quality was assessed in duplicate (by authors M. Y. and M.-C. L.). The quality assessment scoring for nonrandomized studies were performed using the methodological index for nonrandomized studies (MINORS) instrument.20 The quality assessment scoring for randomized trials was performed using the Cochrane Collaboration’s Risk of Bias tool.21 The κ (kappa) statistic was used to examine interobserver agreement for study eligibility. On the basis of the guidelines of Landis and Koch, a κ of 0 to 0.2 represents slight agreement, 0.21 to 0.40 fair agreement, 0.41 to 0.60 moderate agreement, and 0.61 to 0.80 substantial agreement. A value above 0.80 is considered almost perfect agreement.22
Indications for MPFL Reconstruction
Yeung et al.
Citations identified on Ovid Search of Embase, Medline, Cochrane databases (n = 1029) Embase (n = 376) Medline (n = 286) PubMed (n = 314) Cochrane (n = 54) Duplicates removed (n = 549) Excluded studies after title and abstract screen (n = 375) • Nonpatellar instability studies (n = 47) • Radiographic studies (n = 29) • Cadaveric studies (n = 59) • Review articles (n = 65) • Case reports/case series
