G2137 HCPCS - BACK PAIN MEASURED BY THE VISUAL ANALOG SCALE (VAS) OR NUMERIC PAIN SCALE AT THREE MONTHS (6 - 20 WEEKS) POSTOPERATIVELY WAS GREATER THAN 3.0 AND BACK PAIN MEASURED BY THE VISUAL ANALOG SCALE (VAS) OR NUMERIC PAIN SCALE WITHIN THREE MONTHS PREOPERATIVELY AND AT THREE MONTHS (6 - 20 WEEKS) POSTOPERATIVELY DEMONSTRATED IMPROVEMENT OF LESS THAN 5.0 POINTS