Requirements 

You are not required to inform Transport for NSW of a temporary injury but you should use common sense and be safe. I can provide advice about how your medical condition might affect your ability to drive safely and the expected non-driving period. If you’re involved in a crash and it’s found that your health condition was a contributing factor:

• You may be prosecuted;

• Your insurance may not be valid.

Do not drive if:

• You’ve had an anaesthetic in the last 24 hours;

• You are on medication that may impair your ability;

• You may put other road users at risk;

• You can’t operate all vehicle controls;

• You can’t keep one functioning hand on the steering wheel at all times.

https://roads-waterways.transport.nsw.gov.au/roads/licence/health/fit-to-drive.html#Injuries,illnessandmedicalconditions

Driving with a cast or splint

You must be able to:

• Operate all vehicle controls;

• Keep a functioning hand on the steering wheel at all times;

• Safely change gears while keeping one functioning hand on the steering wheel

The information provided by Transport for NSW is vague. I have been given advice, from an Occupational Therapist who specialises in driving assessments, that dispensation is rarely given for the use of a rigid splint or cast. 

If you have a removable splint, ask me if it is safe to remove for driving.

https://roads-waterways.transport.nsw.gov.au/roads/licence/frequently-asked-questions.html#Drivingwithmedicalconditionsordisabilities

Fitness to Drive

You are required by law to inform Transport for NSW of any long-term injury, illness or medical condition which may affect your ability to drive safely. 

Ultimately it is your responsibility to determine whether you are safe to drive. Transport for NSW will consider the advice of your doctors as well as other factors. Some health conditions may require a driving assessment by a suitably qualified Occupational Therapist before a licence can be issued or renewed. You will be notified if necessary.