LeBron James delivered a season-high 41 points in the absence of injured sidekick Dwyane Wade as the Miami Heat clinched a playoff berth with their 99-93 victory over the visiting Philadelphia 76ers on Tuesday.            With Wade sidelined due to an ailing knee, James took on the burden of leading the scoring and  pulling his team to within 2 1/2 games of the East-leading Chicago Bulls.      The 76ers\' defeat dropped them 1 1/2 games behind Boston in the Atlantic Division as they sit seventh in the overall East standings.           In the final month of a truncated regular season, shortened from 82 to 66 games due to a protracted labour dispute, the fight for playoff places continues to gather steam throughout the league.          Well behind Miami, and third in the conference, the Indiana Pacers strengthened their position with a 112-104 comeback win against the New York Knicks.             The Pacers blasted the Knicks 40-17 in the fourth quarter to complete the dramatic turnaround. Despite the loss, New York have a 1 1/2-game advantage in the battle for eighth spot.               Fifth-place Orlando are now just one game up on Atlanta following their 102-95 defeat at the hands of Detroit.              Over in the Western Conference, San Antonio crushed Cleveland 125-90 to pull within two games of top seed Oklahoma City.       The Spurs raced to their eighth straight victory to heap pressure on the Thunder.            Meanwhile, Memphis held off Golden State 98-94 to earn their third consecutive triumph. The Grizzlies are fifth in the West and trail the Los Angeles Clippers by 1 1/2 games.