Palmar pain lasting longer than 4-6 weeks after carpal tunnel release (CTR) has been reported in as many as 36% of cases. The term "pillar pain" has frequently been used but there is no consensus about its definition and pathogenesis. We have made the observation that localized scapho-trapezial joint (STJ) tenderness exists in many patients with prolonged palmar pain and grip weakness after CTR. To study the incidence and outcome of these cases, we reviewed the records of 93 patients who underwent 117 CTR procedures by the senior author over a period of 30 months. 30 procedures in 26 patients were excluded because of confounding factors such as multiple concurrent procedures and a history of previous wrist injury. Prolonged STJ tenderness and grip weakness were found in 11.9% of the cases. 8 wrists in 6 patients were treated with direct injection of Lidocaine and 3 mg of KenologŪ (Triamcinolone acetate) into the ST joint with complete resolution of the symptoms. Rapid resolution of pain with Lidocaine indicated the correct location of the injection. There were no radiographic signs of STJ arthritis in patients who were imaged. The average follow-up for all patients was 23 weeks. The average recovery time after STJ injection was 30 days. The latter group was followed for an average of 32 weeks. CTR initiates an inflammatory process (synovitis) in the ST joint in a subset of patients. This may be a cause of "pillar pain" in as many as 12% of the CTR cases. Careful physical examination is the only diagnostic test required. Injecting a mixture of Lidocaine and KenologŪ will both confirm the diagnosis and treat the inflammation in all cases. The changes in the carpal architecture after CTR redistribute the load along different intercarpal joints. An increased load on the ST joint may initiate an inflammatory process, which can be perpetuated by increased level of activity. Dynamic three-dimensional imaging modalities, developed in our department are currently being used to precisely describe and quantify changes in carpal biomechanics after CTR.