Prognostic value of MRI in arthroscopic treatment of chronic patellar tendinopathy: a prospective cohort study

Abstract

BackgroundTo date, prognostic outcome factors for patients undergoing arthroscopic treatment due to chronic patellar tendinopathy (PT) are lacking. The purpose of this study was to investigate whether preoperatively assessed MRI parameters might be of prognostic value for prediction of functional outcome and return to sports in arthroscopic treatment of chronic PT.MethodsA prospective cohort study was conducted including 30 cases (4 female and 24 male competitive athletes) undergoing arthroscopic patellar release (APR) due to chronic PT. The mean age was 28.2 years (range, 18–49 years) at the time of surgery, and the mean follow-up period was 4.2 years (range, 2.2–10.4 years). Preoperatively assessed MRI parameters included bone marrow edema (BME) of the inferior patellar pole, patellar tendon thickening, infrapatellar fat pad (IFP) edema, and infrapatellar bursitis. Prevalences of preoperative MRI findings were correlated to functional outcome scores in order to determine statistically significant predictors.ResultsAll athletes regained their preinjury sports levels. Athletes featuring preoperative IFP edema showed significantly inferior modified Blazina score (0.6 ± 0.7 vs. 0.2 ± 0.5), single assessment numeric evaluation (SANE; 86.0 ± 8.8 vs. 94.3 ± 7.5), and Visual Analogue Scale (VAS; 1.0 ± 1.2 vs. 0.3 ± 0.8) compared to subjects without IFP edema (p < 0.05). Return to sports required a mean of 4 ± 3.2 months. On average, patients with IFP edema needed significantly more time to return to sports than subjects without IFP edema (6.5 vs 2.8 months; p < 0.05). The simultaneous presence of BME and IFP edema was associated with significantly inferior outcomes by means of the Victorian Institute of Sport Assessment questionnaire for patients with patellar tendinopathy (VISA-P; 88.1 ± 11.9 vs. 98.6 ± 4.2), SANE (84.3 ± 10.2 vs. 93.1 ± 8.3), and VAS (1.3 ± 1.4 vs. 0.3 ± 0.9) compared to an isolated BME or isolated IFP edema.ConclusionsThis is the first study identifying prognostic outcome factors in arthroscopic treatment of chronic PT. Preoperative IFP edema alone or simultaneous BME and IFP edema on preoperative MRI were associated with inferior functional outcome and delayed return to sports. Knowledge of these predictive factors might improve risk stratification, individualize treatment and postoperative rehabilitation, and contribute to improve clinical outcome. Moreover, current findings offer the potential for novel therapeutic approaches.

Arthroscopic patellar release for treatment of chronic symptomatic patellar tendinopathy: long-term outcome and influential factors in an athletic population

“…Radiographic assessment included conventional radiographs (anteroposterior / lateral knee views and axial patellofemoral views), ultrasonography, and magnetic resonance imaging (MRI) of the symptomatic knee joint to exclude intra- and extraarticular co-pathologies. Preoperative MRI evaluation of the patellar tendon and surrounding tissues were conducted utilizing T1, T2, and proton density-weighted sequences as described previously [ 25 – 27 ]. Only if a preoperative peritendinous injection of either local anesthetics or corticosteroids had caused an entire short-term relief of pain, arthroscopic treatment was recommended.…”

“…All surgeries were performed by the same orthopedic surgeon (senior author). The surgical procedure and postoperative rehabilitation program were performed as previously described [ 21 , 25 ]. Briefly, the skin of the inferior patellar pole was marked according to the preoperatively assessed symptomatic anatomic region followed by installation of the anterolateral portal.…”

“…Follow-up assessment included palpation of the inferior patella pole, one legged stance, and light squats. Additionally, the Victorian Institute of Sport Assessment questionnaire for patients with patellar tendinopathy (VISA-P; 0-100 points) and the modified Blazina score served as functional outcome scores [ 16 , 20 , 25 ]. The modified Blazina score functions as a pathology-specific outcome measure including five stages according to symptoms occurring at different levels of sports/activity (0 = no pain, 1 = pain after intense sports activity, 2 = pain at beginning of and after sports activity, 3 = pain during activity at a satisfactory level, 4 = pain during sports activity at a non-satisfactory level, and 5 = pain during daily activity.…”

“…In 2006, Ogon and coworkers presented the technique of an arthroscopic patellar release (APR) [ 24 ]. To assess APR’s mid- and long-term results, Maier et al recently followed patients for a mean of 4.4 years [ 25 ]. The majority of athletes (76.7%) were able to perform at previous sports levels.…”

Impact of Clinical Presentation on Imaging Evaluation to Direct Effective Treatment Strategies

“…43 MRI may help evaluate prognostic factors such as bone marrow edema of the inferior patellar pole and infrapatellar fat pad edema, which are associated with poor functional outcomes and delayed return to activities. 44 These prognostic factors can help with establishing patient expectations before proceeding with surgical intervention.…”