Bring a large pot of salted water to a boil. Add broccoli rabe, and cook until bright green, about 1 minute. Using a wire skimmer or small sieve, transfer to a colander set over a bowl to catch drips (a few bits may remain in cooking water); set aside. Return water to a boil. Add pasta, and cook until al dente, according to package instructions. Drain and return to pot.
Heat a large skillet over medium-high. Add sausage; cook, without turning, until browned, about 4 minutes. Add broccoli rabe, vinegar, and garlic. Cook until broccoli rabe is tender, scraping up browned bits in skillet, 2 to 3 minutes.
Add pasta and oil to broccoli rabe mixture. Season with salt and pepper; toss to combine. Serve.
Broccoli rabe is a slightly bitter-tasting cousin to cabbage and is a good match for Italian recipes, especially pasta. Quickly boiling it tones down its bite without losing many nutrients.