For your next medical check up, take this memo with you and try to explain what happened to you.
ご質問ありがとうございます。
「次の診察で、このメモをもとに自分でケガについて説明して」は英語で「For your next medical check up, take this memo with you and try to explain what happened to you 」と言えます。
ご参考になれば幸いです。