The surgical procedure sounds risky but it seems like Dahlgren's best hope to keep his leg. A bio-synthetic prosthetic would be a viable option but it might have a steep learning curve to adapt to it.
Hope the leg bone doesn't go septic at a particularly critical point. Captain Dahlgren might find himself on a table rather than his chair despite his protests.
The pain Dahlgren faces and how he copes adds an interesting layer to the character. Usually we see injuries handled in a near-miraculous manner in 24th century Trek stories. Glad to see themes of suffering and perseverance in your story. They add depth.