This is the second major tendon rupture that RS has suffered. The. Patellar tendon is under extraordinary stress in everyone with simple knee flexion and those forces in high level athletes may simply exceed the inherent strength of tendons during explosive activity
The recovery for this injury will approach one year. The prognosis depends on the site of rupture - proximal or distal avulsion versus midsubstance tear.
I usually passed a retention wire through the patella and tibia to prevent quad contraction or accidental knee flexion from disrupting the repair.
A failed repair is difficult to salvage. I actually devised a salvage procedure that I employed on a former Navy football player that was washed out of the USNA after a failed repair. I lost follow up , but another MD notified me that he had returned to semi-pro football, which I would never have recommended.
RS will have the best surgical and rehab treatment available but it will be a long year