Free flap reconstruction in an older patient with head and neck cancer is usually discussed in terms of whether the flap will survive. A systematic review of eleven studies using validated frailty indices — the 5- and 11-factor Modified Frailty Index, Geriatric 8, Risk Assessment Index, Prognostic Nutritional Index, Cervical Paraspinal Skeletal Muscle Index and others, eight of them rated good quality on the Newcastle-Ottawa Scale — suggests that is the wrong question.

Frailty was consistently associated with medical complications, longer hospital stay and a higher likelihood of not going home at discharge. It also predicted impaired swallowing recovery and a longer requirement for enteral nutrition. What it did not consistently predict was surgical complications or short-term mortality. In other words, the flap tends to be fine; the patient's medical course and their functional recovery are what frailty is telling you about.

One finding has immediate practical weight: measures incorporating nutrition or sarcopenia outperformed frailty indices alone in predicting postoperative complications. That points at cheap, available assessments — the Prognostic Nutritional Index from routine bloods, paraspinal muscle area measurable on the staging scan the patient has already had — rather than a new questionnaire. It also gives a specific shape to the preoperative conversation: not 'can you survive the operation', but 'this is likely to mean a longer admission, a period of tube feeding and possibly not going straight home', which is a discussion families can prepare for.

Measure a frailty index preoperatively, but weight nutritional and sarcopenia measures most heavily.
Take the Prognostic Nutritional Index from bloods you are already sending.
Measure paraspinal muscle area on the staging imaging rather than ordering anything new.
Counsel on length of stay, tube feeding duration and discharge destination — those are what frailty predicts.
Do not use frailty alone to decline reconstruction; it did not consistently predict surgical complications or early death.

Why it matters

Frailty is being used to judge whether a patient can withstand the operation, and what it actually predicts is everything that happens afterwards.

Don't overread it

Eleven heterogeneous observational studies using seven different frailty instruments — the direction is consistent, but no single tool or threshold is validated by this.