Hundreds of National Labor Relations Board decisions were thrown into legal limbo Thursday by a Supreme Court ruling that President Obama overstepped his authority by naming three members to the panel while the Senate was on a short break.

Yet little is likely to change because those decisions are almost certain to be reaffirmed by the current board, labor lawyers and others who regularly deal with the agency said.

“Obviously dozens, if not hundreds of cases, will be invalidated,” said Joel S. Barras, a lawyer who represents employers in labor litigation. “But I would anticipate the new board reaching the same conclusions that the previous board did.”

Given that reality, Barras said it is likely that most of the cases thrown into question by the high court’s decision will likely be dropped, unless employers were simply looking to buy time.

The NLRB said it is examining the court’s decision to see whether it requires the agency to re-ratify the decisions made during the 19 months the recess appointees took part in its deliberations, an agency spokesman said. If the board does decide to reexamine each case, then it could be backlogged for months.

“We are analyzing the impact that the Court’s decision has on Board cases in which the January 2012 recess appointees participated,” Mark Gaston Pearce, NLRB chairman, said in a statement.

The NLRB confronted a similar predicament in 2010 when the high court threw out decisions made when the labor board attempted to operate with only two of its seats filled. That decision left about 600 cases decided during the 27 months when the board had only two members into limbo. But, in the end, the vast majority of those cases were never brought back to the board, an NLRB official said.

The latest case could result in a similar outcome. “From a financial standpoint, companies are going to have to make a determination about whether they want to pursue these cases, with the likelihood of different decisions being as slim as they are,” said Joe Trauger, vice president for human resource policy for the National Association of Manufacturers.

The NLRB adjudicates employment disputes and oversees union organizing elections, making it a hot spot for partisan wrangling. For years, Democratic senators have been blocking appointees by Republican presidents, and Republican senators have been blocking those nominated by Democratic presidents.

Frustrated by Senate Republicans who were stalling his nominees to the board and depriving it of a quorum, Obama appointed three members to the five-person NLRB in January 2012 while the vast majority of senators were on vacation. But in anticipation of that, Republicans had already decided to force the Senate to hold brief pro forma sessions in which no business was conducted, with the specific intent of blocking recess appointments. The legitimacy of these three appointments set off a court battle that until Thursday had not been resolved.

The NLRB finally got five fully confirmed members for the first time in a decade last summer — part of a Senate deal after Democrats threatened to end the gridlock by altering Senate rules to eliminate filibusters for most presidential nominations. But even after the deal, new disputes erupted, and Democrats enacted the rule change last November.

The high-court case resulted from a dispute involving Noel Canning, a bottling company in Washington state. The labor board ruled that the company had engaged in an unfair labor practice by refusing to enter into a collective bargaining agreement. Saying that the NLRB had no standing to make the decision because Obama’s recess appointments were improper, the company argued the board’s ruling should be struck down. The court unanimously agreed.

Most of the NLRB decisions thrown into question by Thursday’s Supreme Court ruling are noncontroversial, board officials said. But 100 are before appeals courts because of the legal questions surrounding Obama’s recess appointees.

“The impact of [Thursday’s] ruling is far less than it might have been, because there is now a full complement of Senate-confirmed members of the NLRB and a Senate-confirmed NLRB general counsel,” said AFL-CIO President Richard Trumka in a statement.

Still, business groups applauded the ruling. “Today’s decision is a victory for the rule of law,” said Thomas J. Donahue, U.S. Chamber of Commerce president and chief executive. “The president’s unprecedented recess appointments left the NLRB in legal limbo, causing major uncertainty for both employers and employees alike.”