Plication of The Medial Patellofemoral Ligament for The Treatment of Chronic Patella Dislocations and Refractory Patellofemoral Syndrome. A Retrospective Case Series and Review

Abstract

Background: Anterior knee pain accounts for 25-40% of knee pain visits in sports medicine clinics. Refractory Patellofemoral Syndrome (RPS) and Chronic Patella Dislocations are often multifactorial but commonly the pain originates from impaired patellar tracking and increased lateral patellar tilt. The compression of the subchondral bone has been correlated to the pain as well as from the synovium, retinaculum, and associated neuromuscular structures. The plication of the Medial Patellofemoral Ligament (MPFL) counteracts these compressive and tilting forces improving symptoms of RPS and recurrent patella dislocations. The goal of this project was to evaluate the outcomes associated with MPFL plication. Study Design: Case Series; Level IV Methods: A retrospective analysis of patients with recurrent patella dislocations, Refractory Patellofemoral Syndrome (RPS) or Patellofemoral Pain Syndrome (PFPS) treated with plication of the MPFL between 2009 2018 with minimum four month follow up. The primary outcome variable was patient overall satisfaction, Visual Analogue Scale for Pain (VAS) and Kujala (Anterior Knee Pain) Score. Results: Seven patients met the inclusion criteria. Their demographic and pre-surgery details are in Table 1. A large majority of patients (85.7%) were satisfied, and VAS pain scale ratings were four or less. Only one of the seven patients was not satisfied (Table 2), and that individual also had the lowest Kujala score. The VAS pain scale and the Kujala score were not correlated (Spearman rank correlation, rho=-0.218, P=0.638; Figure 1), nor was there a clear relationship between time since surgery and Kujala score (rho=0.607, P=0.167; Figure 2). Conclusion: Plication of the MPFL has a high success in improving both Kujala (Anterior Knee Pain) Score and Visual Analogue Scale (VAS) as well as return to regular activities. We believe this is a safe and effective technique in improving chronic patella dislocations and Refractory Patellofemoral Syndrome with minimal perioperative morbidity. Introduction Patella Instability/ Patella Dislocation Patella instability and dislocation are not covered under the umbrella of RPS or PFPS, however it can be a source of anterior knee pain, especially in younger female patients ages 10-17 [1]. The average incidence of primary patellar dislocation is roughly 5.8 per 100,000 cases [1]. Causes of patella instability/subluxation and dislocation include trauma, general lateral ligamentous laxity, Citation: Hoang V, Moyer B, Talle M, Vanier C, Watson T, Bascharon, R, Lee, D, Liu, N (2019) Plication of The Medial Patellofemoral Ligament for The Treatment of Chronic Patella Dislocations and Refractory Patellofemoral Syndrome. A Retrospective Case Series and Review. Sports Injr Med 5: 155. DOI: 10.29011/25769596.100055 2 Volume 5; Issue 01 Sports Injr Med, an open access journal ISSN: 2576-9596 lateralized Q-angle, recurvatum, tibial external rotation, vastus medialis weakness, trochlear dysplasia, and/or genu valgum without displacement from the groove in subluxation and complete displacement in dislocation [2-4]. The excessive lateral tilt and glide in subluxation produces a redistribution of forces along the patellar articular surface causing pain and feelings of instability. Dislocations are also a source of pain and involve complete displacement, often laterally, but in rare cases can occur medially and superiorly [2,3,5,6]. Studies have shown that dislocations can lead to recurrent instability, decrease in activity, cartilage damage, fractures, and progression of osteoarthritis [1,7-10]. In the interest of pain relief, joint preservation, and restoration of biomechanics, either conservative or surgical intervention can be beneficial. Extensive long-term clinical study on conservative treatment of patellar dislocations is lacking. However, a study done by Maenpaa and Lehto found that immobilization of the knee in extension after a primary dislocation for six weeks reduced the risk of secondary dislocation three-fold compared to patients that were not [7]. This may provide enough of an opportunity for the MPFL to heal or other structures to tighten up prior to therapy, but more research is required in this area [3]. Patients with patellar instability and dislocations are at a higher risk of subsequent dislocations and even after conservative treatment, experience a 15-44% rate of recurrence [1,3,7]. These patients may benefit from surgical intervention. This, however, remains controversial. According to a review included in a study by Jain, et al. (2011), there is insufficient evidence to support immediate surgical stabilization of the patella after an initial dislocation, and only after a second dislocation should it be considered due to an increased risk of subsequent dislocations.3 In patients with lateral subluxations and repeat dislocations, the MPFL may be damaged or stretched and in need of repair. This procedure’s utilization has increased in recent years, and in spite of a noted complication rate of 26%, [11] a number of retrospective studies claim excellent outcomes from 80-96% of patients improving even when used to repair previously failed surgical interventions for instability [2,1215]. Refractory Patellofemoral Syndrome (RPS) or Patellofemoral Pain Syndrome (PFPS) Anterior knee pain has a high incidence affecting 22/1000 patients/year and accounts for 25-40% of knee pain visits in sports medicine clinics [16,17]. Pain originating from impaired patellar tracking as a result of tight lateral soft tissues with compression of the lateral facet against anterolateral femur and increased lateral patellar tilt is often classified as Refractory Patellofemoral Syndrome (RPS) or Patellofemoral Pain Syndrome (PFPS) [18]. The compression of the subchondral bone has been correlated to the pain, but pain can also be associated with the synovium, retinaculum, and associated neuromuscular structures [19]. Development of Refractory Patellofemoral Pain Syndrome is multifactorial. RPS has been often observed in active individuals and affects more women than men as a result of a widened Q-angle [17,20,21]. Other anatomical and biomechanical contributing factors include tight lateral retinaculum, tight IT band, foot pronation, externally rotated tibia, weak hip abductors and external rotators, weak vastus medialis, and injury to the extensor mechanism [8,21]. Weakness in the external rotators or abductors of the hip resulting in internal rotation of the femur, over eversion of the foot resulting in internal tibial rotation, or a combination of both may result in a functional or dynamic valgus deformity, also contributing to patellar maltracking [22]. Patients present with anterior knee pain from overuse, positive theatre sign (pain with activity after prolonged sitting), positive patellar compression test, and pain climbing/descending stairs [16,23-25]. Symptoms are exacerbated with flexion and can be recreated in the clinic utilizing a squat test. If hip abductor strength is in question, a single leg squat test can be utilized to identify hip muscle dysfunction [22]. Nonoperative Treatment of Refractory Patellofemoral Syndrome (RPS) or Patellofemoral Pain Syndrome (PFPS) Current treatments are centered on pain relief with eventual return to presymptomatic activity and improved patellar alignment. Treatment plans are evaluated on a per patient basis beginning with a focus on non-operative methods. Initially, patients are to avoid activities that cause pain (ie. running, high impact, stair running/ hill climbs) and are prescribed NSAID pain relievers. According to a meta-analysis of the Cochrane database of pharmacotherapy in the treatment of patellofemoral pain, one study showed use of Naproxen provided significant pain relief for 2-3 weeks, but was not significant in long term treatment. The same analysis found there is little evidence supporting the use of NSAIDS for reduction of knee pain in acute or chronic cases [26]. The analysis also explored the use of intra-articular corticosteroid injections and Glycosaminoglycan (GAG) derived viscosupplementation and it was determined that this form of treatment also lacks support from literature [26,27]. Over the course of five weeks, four test groups were compared, including one group consisting of GAGs with lidocaine injections, one group of two injections of saline and lidocaine, and no injections in two other groups participating in quadriceps strengthening physical therapy. The study found a significant difference in relief of symptoms between the GAGs with lidocaine versus the no injection group, but the injections failed to completely remedy patients’ symptoms which returned within six months [26,27]. Patellar Taping and Bracing A number of studies have found use of patellar taping and Citation: Hoang V, Moyer B, Talle M, Vanier C, Watson T, Bascharon, R, Lee, D, Liu, N (2019) Plication of The Medial Patellofemoral Ligament for The Treatment of Chronic Patella Dislocations and Refractory Patellofemoral Syndrome. A Retrospective Case Series and Review. Sports Injr Med 5: 155. DOI: 10.29011/25769596.100055 3 Volume 5; Issue 01 Sports Injr Med, an open access journal ISSN: 2576-9596 bracing reasonable when coupled with exercise therapy. Pfeiffer, et al. utilized tape in a medial direction and evaluated its ability to decrease lateral patellar displacement. The results were significant, but only before intense exercise, indicating that tape coupled with supervised, low intensity exercise therapy can be beneficial [28]. Two meta-analyses, one published in 2002 and another in 2008, also found that tape coupled with exercise provided significant improvement in reduction of pain compared to exercise alone. Sham tape also showed positive results, indicating that a placebo effect can also play a role in improvement of symptoms [29,30]. Unfortunately, the studies involved were focused on short-term results and the long-term effect