The Crusade of 1101 makes it through Anatolia intact, giving the Turks a mild defeat along the way, they help to quickly expand the borders of Outremer. The Second Crusade makes it through Anatolia intact, giving the Turks a bloody nose along the way, they capture Damascus.
Andronicus Komnenos comes to the throne on the death of Manuel at the expense of his young nephew. Andronicus attacks the landed nobility like a rabid dog for 5 years before being deposed in favour of his nephew. His nephew Alexios II manages to take advatage of the damage Andronicus has done to the nobility and recentralises some powers into the Emperors hands and redistributes land to military peasants in something akin to the Theme system.
Saladin's big acheivement is throwing the Crusaders out of Damascus, they still hold the bulk of the Holy Land including Oultrejordain, the key to holding Jerusalem.
The empire holds on as a centralised state until the early modern era when the rest Europe follows suit. The rest writes itself.