I was part of a four-strong club group climbing this Grade 2 scramble in the Ogwen valley. The group, which had no experience of the route, comprised myself (intermediate scrambler at this time), Person A (aspirant MIA), Person B (experienced climber) and Person C (novice scrambler). I solo'd alongside Person A and watched them build belays to bring Person C up on a rope. Person B solo'd alongside Person C to give them confidence. Midway up the route it began hailing/snowing and we started to encounter iced up rock. As the weather worsened Person C began to lose confidence and progress slowed significantly. Following discussion with Person A it was agreed that I would solo onwards to confirm the route to the relative safety of Seniors Ridge. I did this successfully before downclimbing and leading the group upwards. Around 20m from the top of the route we encountered an 'easy' 3m slab above a large grassy ledge. As I climbed this slab I slipped and slid around 2m onto the ledge, dislocating my left patellar in the process. This kneecap had dislocated in a trampolining accident (!) several years previously. Fortunately I was able to relocate the kneecap and a painful descent followed - including several abs down verglassed steps on Seniors Ridge and much hopping.