TALLAHASSEE — A South Florida appeals court Wednesday overturned a circuit judge's constitutional ruling that threatened a major underpinning of the state's workers' compensation insurance system.A three-judge panel of the 3rd District Court of Appeal tossed out the ruling, finding that plaintiffs did not have legal standing and the case was moot. The appeals court did not weigh in on whether the workers' compensation system was constitutional.The constitutional question dealt with a longstanding concept in Florida that cases involving injured workers should be handled through the workers' compensation system instead of through civil lawsuits. But Miami-Dade Circuit Judge Jorge Cueto ruled last year that the law preventing cases from going to civil trial was unconstitutional, at least in part because of legislative changes in 2003 that reduced benefits.The case originally involved Julio Cortes, who alleged he was injured in 2010 while operating equipment for Velda Farms LLC. The constitutional issue was later dismissed from the Cortes dispute, but the challenge continued with the involvement of two legal groups that had intervened in the case — Florida Workers' Advocates and Workers' Injury Law & Advocacy Group — and Elsa Padgett, an injured Miami-Dade County worker.But the appeals court agreed with arguments by Attorney General Pam Bondi's office that the two groups and Padgett could not pursue the constitutional question in the case. It said, in part, that the issue became moot when it was dismissed in the Velda Farms dispute. Similarly, it found that the two groups and Padgett did not have standing to pursue the constitutional question.The Miami-Dade County case is one of three workers' compensation disputes that recently have drawn attention from business, labor and legal groups, with two of the cases pending at the Florida Supreme Court.One of those Supreme Court cases, which stems from injuries suffered in 2009 by a South Florida man, Marvin Castellanos, during an altercation with another worker at their employer, challenges the constitutionality of limits on attorneys' fees in workers' compensation cases.The other case involves injuries suffered in 2009 by St. Petersburg firefighter Bradley Westphal and focuses on a two-year limit on what are known as "temporary total disability" benefits. Westphal received those benefits but then had a gap of several months before he could get permanent benefits.