Medial Abrasion Syndrome:  A Neglected Cause of Persistent Pain After Knee Arthroplasty

Abstract

Background: Persistent postoperative pain (PPOP) has detracted from some otherwise successful knee arthroplasties. This study investigated medial abrasion syndrome (MAS) as a cause of PPOP after knee arthroplasty and presented the technique and outcome of arthroscopic medial release (AMR) procedure to treat such patients. Methods: In a one-year period, the author performed unicompartmental or total knee arthroplasty (the UKA or TKA group) that also eliminated MAS on 196 knees of 150 patients at advanced stages of knee osteoarthritis (OA). During the same year, 16 knees of 16 patients with unknown causes of PPOP after knee arthroplasty were referred to the author for the AMR procedure (the AMR group). Subjective satisfaction, Knee Society Score (KSS), and Knee injury and Osteoarthritis Outcome Score (KOOS) evaluations were used for outcome study.Results: All 166 patients were followed up for more than 3 years (mean: 3.7 years, 3.1-4.2) for outcome study. All knees receiving arthroplasty showed pathologic medial plicae of various severities at the time of arthroplasty. Only 2 patients suffered PPOP: one was a neglected tibial plateau fracture with residual varus deformity after UKA and the other was a late infection after TKA and received revision. The satisfactory rate was 98.8% in the UKA group, 99.1% in the TKA group, and 100% in the AMR group. The Knee Society scores and all subscales of KOOS were statistically improved in all groups.Conclusion: MAS is a cause of pain in patients who have received knee arthroplasty, and MAS should be managed before wound closure to ensure a successful knee arthroplasty. PPOP after knee arthroplasty can be caused by MAS, which can be managed by AMR.

Noise around the Knee

“…The plica is a fold in the synovium that represents an embryological remnant of the development of the synovial cavity in the knee. 15) Although the reported prevalence of medial plica ranges widely from 22% to 95%, 34 35) the pathological plica, characterized by inflammation, thickening, and/or reduced elasticity, can produce clinically relevant pain and crepitus. Friction between the medial plica and the facing medial femoral condyle, occurring during activities of daily living, can increase the severity of pathological changes in the medial plica and give rise to clinical symptoms, such as synovitis and pain.…”

“…Friction between the medial plica and the facing medial femoral condyle, occurring during activities of daily living, can increase the severity of pathological changes in the medial plica and give rise to clinical symptoms, such as synovitis and pain. 35) Therefore, crepitus in the medial plica area requires attention if it produces a painful click. 15 34 35) …”

“… 35) Therefore, crepitus in the medial plica area requires attention if it produces a painful click. 15 34 35) …”

Arthroscopic Cartilage Regeneration Facilitating Procedure: A Decompressing Arthroplasty for Knee Osteoarthritis

“…Although the prevalence of medial plica ranges widely, from 18% to 95% [22]- [24], it is generally agreed that this structure can produce knee pain and can be successfully treated by arthroscopic resection in the event that it becomes in amed, thickened, and/or less elastic [22], [25], [26]. Abrasion phenomenon between the medial plica and the opposite medial femoral condyle has been described in patients with knee OA [6], [27], [28]. The repeated injuries elicited by this abrasion phenomenon was found to trigger IL-1ß production, thus enhance the expression of MMP-3.…”

Assessment of Diagnostic Accuracy of Knee MRI in Detecting Medial Parapatellar Plicae versus Knee Arthroscopic Findings

“…Sakakibara [4] reported a rate of 55% and cadaveric study showed an incidence of 34%. The prevalence was even found to be 95% in patients suffering from chronic knee pain in a cohort of more than 40-years-old individuals (Figure 1) [5].…”