Introduction
Patella plicae are normal anatomic structures of the knee, typically asymptomatic and of little clinical significance (Giffith & LaPrade, 2008; Sznajderman, Smorgick, Lindner, Beer, & Agar, 2009). Plicae are remnants of mesenchymal tissue that is incompletely resorbed, leaving "pleats" of tissue behind in the knee (Camanho, 2010; Dupont, 1997). It is estimated that up to 50% of the population has some form of persistent plicae of the knee (Camanho, 2010; Hayashi et al., 2013). Irritation of the patella plica, usually from strenuous activities involving repetitive flexion and extension of the knee, results in a dull, aching pain of the anterior knee (Giffith & LaPrade, 2008). This is a common cause of anterior knee pain, although frequently misdiagnosed (Al-Hadithy, Gikas, Mahapatra, & Dowd, 2011). Mediopatellar plica irritation is the most common cause of knee pain related to this disorder (Farkas, Gaspar, & Jonas, 1997). Patients typically describe a dull, aching pain of the anterior knee, medial to the patella and superior to the joint line (Sznajderman et al., 2009). The majority of cases are successfully treated with nonoperative interventions (Griffith & LaPrade, 2008). Here is presented a case of patella plica syndrome, with associated imaging, that unfortunately was unresponsive to conservative management.
Case Presentation
A 20-year-old man presented to the orthopaedic clinic for evaluation of right anterior knee pain, present for over 8 months. His symptoms started while participating in a marathon. He noted significant anterior knee pain starting around mile 20, persisting and gradually worsening through completion of the race. His knee continued to bother him for several weeks, noting swelling and anterior pain described as aching and "sore." He self-diagnosed "runner's knee" and treated with activity modification, icing, stretching, and intermittent Ibuprofen. The more acute symptoms gradually subsided. He was able to resume day-to-day activities but noted inability to return to more strenuous activities, such as running, without increased anterior knee symptoms. He described a vague soreness, periodic catching, and a "grinding" sensation when symptoms at their worst. His primary goal in seeking care was to return to running with intent to complete another marathon.
On initial presentation, he was alert, oriented, and in no apparent distress-displayed a nonantalgic gait without use of an assistive device; no deformity, swelling, or discoloration about the knee or leg; no focal tenderness to palpation; smooth, symmetrical, and painless range of motion of the knee with notable hamstring tightness in extension; did note a borderline hypermobile patella and a positive j-sign; otherwise, stable ligamentous testing; strength 5/5 in all muscle groups; distally neurovascularly intact; displayed a negative bounce home, McMurray, Wilson, and patellar apprehension test; positive Clarke's and patellar tilt.
Radiographs taken showed no evidence of fracture or dislocation-mild lateral deviation and tilt of patella (see Figure 1).
Initial Management
The patient was initially diagnosed with patellofemoral syndrome and prescribed a course of conservative treatment including referral to physical therapy, continued activity modification, and use of naproxen (Giffith & LaPrade, 2008; Sznajderman et al., 2009). We also discussed brace wear but he was not amenable to that. The focus of therapy was on patellar stabilization and tracking exercises, quadriceps strengthening, hamstring, and IT band stretching as well as pain relief modalities and gait training (Griffith & LaPrade, 2008; Schindler, 2014). After 6 weeks, he noted no improvement and was seen back in the clinic for follow-up. The examination was unchanged and an MRI of the knee was obtained to further assess the underlying cause of his symptoms.
MRI imaging of the knee revealed inflammation and prominence of the mediopatellar plica (see Figure 2).
Subsequent Management
Results of the MRI were discussed with the patient. At the time, he was preparing for a hiking trip and so discussed the role of intra-articular steroid injection. This is a common intervention for patella plica syndrome when initiation of therapy exercises and activity modification is not sufficient and the patient has continued symptoms (Schindler, 2014; Sznajderman et al., 2009). Intra-articular injection was provided and he noted relief for about 2 weeks. Unfortunately, the symptoms returned and further attempts at management with physical therapy treatments and modalities were ineffective. He continued to be symptomatic with attempts at strenuous activity. With this, he was referred to a sports medicine surgeon to discuss arthroscopic resection of the identified patella plica as usually appropriate when conservative management has failed (Farkas et al., 1997; Griffith & LaPrade, 2008; Sznajderman et al., 2009).
Discussion
Patellar plica syndrome is a common cause of anterior knee pain (Griffith & LaPrade, 2008). Usually reported as an insidious onset of knee pain, patella plica should be considered upon initial presentation of those with anterior knee pain, especially in the setting of known repetitive activities (Al-Hadith et al., 2011; Griffith & LaPrade, 2008). Modalities such as MRI and ultrasound are beneficial tools in reaching a definitive diagnosis, confirming the presence of prominent, inflamed patella plica (Al-Hadithy et al., 2011). Conservative management focuses on quadriceps strengthening, patellar tracking/stabilization exercises, IT band and hamstring stretching, activity modification, and the use of nonsteroidal anti-inflammatory drugs (Griffith & LaPrade, 2008; Schindler, 2014; Sznajderman et al., 2009). Arthroscopic intervention of symptomatic plica should be considered in those that are refractory to at least 6 months of conservative management (Al-Hadithy et al., 2011). Arthroscopy is considered the "gold standard" when conservative measures fail (Farkas et al., 1997). Positive prognostic indicators for surgery include young age, localized symptoms, shorter duration of symptoms before seeking treatment, and the absence of chondromalacia (Schindler, 2014). The advanced practice nurse should be aware of this diagnosis, appropriate treatment plan, and work-up, providing reassurance to patients that the majority of cases can successfully be treated with conservative management.
References