Is Triangular Fibrocartilage Complex Injury Associated with Extensor Carpi Ulnaris Tendinitis or Tenosynovitis? A Case-control Comparative Study: Level 3 Evidence

Hypothesis: After treatment of triangular fibrocartilage complex (TFCC) injuries, the ulnar wrist may experience persisting pain, suggesting the presence of some other pathology. We compared the wrists of patients who have TFCC injuries before treatment with those of volunteers who have no ulnar wrist pain. We hypothesized that TFCC injuries are frequently complicated by extensor carpi ulnaris (ECU) tendinitis or tenosynovitis. Methods: Altogether, 46 volunteers (21 male, 25 female; mean age 30.8 years) who had no pain in the ulnar wrist and 46 TFCC patients (22 male, 24 female; meanage35.5years)with a positive fovea sign andwhosepain diminishedafter injection of 0.5ml lidocaine at the ulnar fovea were compared. In all, 20 right and 26 left wrists of the volunteers were evaluated, as were 22 right and 24 left wrists of the patients. Wrists of both groups underwent magnetic resonance imaging (MRI).Wristswere imagedwith the subject prone, arms over the head, and forearm pronated. A microscopy coil was placed on the center of the ulnar head. All MRI scans were obtained using a 1.5-T system (Gyroscan NT Intera; Philips Medical Systems, Best, The Netherlands). Coronal and axial twodimensional gradient-echo images were obtained. ECU tendon pathology (tendinopathy or tear) was classified into three categories (T1: normal; T2: multiple cracks; T3: changed intensity of tendon). Surrounding ECU tendon pathologies (e.g., tenosynovitis) were also classified into three categories (S1: normal; S2: effusion in sheath; S3 disruption of sheath) (Figure 1). There were some overlaps. The width, depth, opening angle, and radius of the curvature of the ECU groove were determined using imaging software based on a previous report (Figure 2) (reference 1). The image slice in which the ECU groove was largest was chosen for measurement. Statistical analysis was performed with ManneWhitney’s U-test. A P< 0.05 significance level was used in all cases. Results: T2 pathology in the patient group (T1: 29; T2: 15; T3: 20) was significantly more frequent than in the volunteers (39; 4; 20, respectively). Surrounding pathology S2 was significantly more frequent in the patient group (S1: 35; S2:11; S3: 0) than in the volunteers (40; 4; 0, respectively). There were no significant differences between groups regarding the width, depth, opening angle, or radius of the curvature.