It was a surprise finding Murray Louis with a cane in hand, hobbling down the Madison Hotel Lobby like an arthritic nonagenarian. For a moment, it wasn't easy to recognize the man whom one noted critic had hailed only a couple of years ago as "unquestionably the greatest virtuoso modern dance has ever produced."

Everything else about him -- the smile, the fresh suntan, the vehemently gesticulating free hand -- contradicted the image of disability, and the explanation was quick in coming. "I just had a fantastic new kind of surgery with lasers on my knees, both of them," said the 53-year-old dancer-choreographer. "Would you believe I'm just four days out of the hospital? I went in Friday, had the operation Saturday, and was out on Sunday -- I walked out!"

Louis won't be dancing tonight when his troupe -- the Murray Louis Dance Company -- appears at the Carter Barron Amphitheatre, but he does expect to be back on stage in about a month, when the company commences a Far East tour of Hawaii. For the time being, he can cope with the pain he experiences in walking, which he says is "no more than I'd feel after an afternoon's rehearsal on my knees." "But you know," he adds, "it's only a dancer, with the pain threshold we develop, and our discipline who could get back into action so quickly."

His knee problem was "just deterioration," Louis says. "I've used these legs for so long. I finally decided to do something about it to take away the dreadful pain I've been dancing with for 14 months, and because the pain was really beginning to limit my movement range."

He was prepared to undergo conventional surgery when -- the day before the operation -- someone told him about the new laser technique, which involves no cutting and no scalpel. "The laser snips away the frayed cartilage that's causing the problem, and suction draws it out," he explains. "You know how it is when you didn't know something existed and suddenly everybody around you has had it. I discovered this was the operation President Ford had, and Tommy Tune, the Broadway choreographer, who told me, 'Murray, it's fantastic, you won't believe it.' Even the guy who came to fix my air-conditioner has had the procedure." Now that Louis himself has been through it, he's jubilant: "It's miraculous -- even now, when I can hardly move my legs, the release from the old pain has made me a new person."

The "new" Murray Louis, though, is just as peppery and outspoken as the old, as his just-published book of essays and commentaries, "Inside Dance," testifies. The book starts with a typically unconventional piece about sweat ("Sweating is a vastly underrated and generally maligned condition of life, and I'm here to declare, 'Sweat is Beautiful.'") and goes on to deal with such topics as critics, creativity, Rodolf Nureyev (with whom Louis has worked closely), eating and "Identity: the Me-Factor."

Quite a few passages are apt to raise eyebrows (e.g., "I won't discuss the miracle of critics who arrive drunk and sleep through a performance, and yet manage to meet their deadline"). At the same time, the compact volume has already amassed an imposing cadre of admirers. The foreword by Marcel Marceau likens Louis to Duse, Mark Twain and Buster Keaton. And there are jacket blurbs from Lillian Gish, Irene Worth, Dave Brubeck and Robert Joffrey.

At the end of the year, Louis will appear as guest artist with the company of his longtime mentor and friend, Alwin Nikolais, in a mammoth new multimedia production involving acrobats, ballet dancers, a huge puppet and films by Ed Emshwiller, scheduled for a month's run at the Paris Opera. Before that, he'll launch another New York season with his company, which will feature, among other things, a new work called "The City" which he envisions as a sort of choreographic mash note to Manhattan.

"I decided it was time to do a piece on a love theme," he says. "I said to myself, 'Now, who do I really love? Who really loves me?' New York was the answer that kept coming back. When I leave it, I'm homesick. When I'm angry, I go prowl the streets. When I want to be alone, I bury myself in the museums. 'Who do you run to?' I asked myself. 'Who holds your hand?' I realized it was a love affair. So it's a piece about my city."

Among other projects he's got going are a new solo for himself called "Apparitions"; an abbreviated staging for the Jose Limon company of the two-hour "Cleopatra" he created for the Royal Danish Ballet a couple of years back; and a comprehensive biography of Nikolais, to be published by Macmillan. He also recently finished filming himself performing 40 of his solos stretching back over 25 years of choreography -- about three hours of footage. "It just nearly killed me," he says."It got me into so many different styles. I had to use muscles I thought I had buried years ago."

At Carter Barron, the Murray Louis Dance Company will perform four works from the mid- to the late '70s: "Schubert," an abstract setting of three movements from Schubert's "Trout" Quintet; "Porcelain Dialogues," to the best known of Tchaikovsky's string quartets; "Figura," originally done for the Limon troupe; and "Glances," with a score by Dave Brubeck.