Quadriceps strength and pain during isokinetic concentric and eccentric contractions before and after arthroscopic excision of synovial plicae

The functional efficacy of arthroscopic excision of the plica in 33 patients (27 men, six women) was assessed based on quadriceps performance and pain relief, prior to and following intervention. The concentric (C) and eccentric (E) strength of the quadriceps was measured isokinetically at low and medium velocities (30 and 120°/s) while the pain level during these efforts was recorded using the Borg modified (0–10) pain scale. Following the intervention, there was on average 16% improvement in the strength of the quadriceps of the involved side versus 5% in the uninvolved side. The effort induced pain was reduced on average 4.76 and 4.21 points during C and E contractions, respectively, which amounted to an almost absolute pain relief. In view of these findings, it is suggested that preoperative qualitative assessment of the pain during isokinetic testing together with assessment of quadriceps functional performance may be effectively and routinely integrated within the general framework of knee examination, in suspected plica pathology. The improvement of pain and quadriceps function during postoperative isokinetic reassessment confirm the hypothesis that the suprapatellar and the mediopatellar plicae are potent causes of anterior knee pain.