Core strengthening exercises and physical therapy exercises are an excellent way to both rehabilitate from injuries and increase the strength of the core muscles. Core exercises can be used to prevent back pain, protect the spine and strengthen the pelvis.
Rehabilitation can be a long and often arduous process, improving your core strength can be an important part of this process. Obviously every injury is different and requires different types of attention to recover from the specific injury. The most important thing to do when recovering from an injury is to consult a professional and make sure your plan is both reasonable and safe. Here are some exercises that you could consider adding into your rehabilitation process if they seem appropriate.
Complete 3 rounds
The key is to find a good physiotherapist who can give you advice on your specific injury and how to rehabilitate it. Every injury is different and needs different treatment. Once it has been properly rehabilitated it can be strengthened by using core exercises in conjunction with full body resistance training.
The spine cannot be made stronger as such, but you can increase its bone density, so it really depends on how you define strong, if you mean making it more resilient to injury then yes. Core exercises can absolutely make the back stronger, especially the lumbar spine.