The phone in this clinic rings differently in the seven days after an injection than at any other time. Not emergencies, mostly. Just people who were handed a printed sheet at discharge and have now read it eleven times in a hotel room.

I’ve kept a note of the calls. Five of them come up again and again, and the answers are less tidy than the sheet suggests.

“Can I take ibuprofen? I read it kills the cells.”

Usually a man in his fifties, usually at night, usually with his knee up on a pillow and his laptop open.

Here’s what the reading is based on. A 2010 laboratory study in the Journal of Cellular and Molecular Medicine ran seven common NSAIDs against cultured mesenchymal stem cells — diclofenac, ketorolac, meloxicam, piroxicam, parecoxib, ketoprofen, lornoxicam. At blood concentrations you’d actually reach on normal doses, none of them slowed cell division much. What they disturbed was the step where cells start making cartilage: diclofenac pulled sulphated glycosaminoglycan output down about 45%, ketorolac about 55%, the COX-2 selective drugs somewhere around 22% and 27%.

Cells in a dish. Not a knee. Not a person, not a dose, not a fortnight.

So the honest answer is neither of the two confident ones. It isn’t “never take anything” — patients who do that spend four days in avoidable pain and arrive furious. And it isn’t “take whatever”. We suggest paracetamol at proper doses, and we suggest laying off routine anti-inflammatories for a week or two after a joint injection. Small cost, direction of the evidence is unfavourable, that’s all.

Two things genuinely cross a line. Painkillers you weren’t prescribed. And a strong anti-inflammatory, oral steroids especially, started without telling us — because some protocols exclude patients who’ve had a steroid shot into that same joint recently, and that’s not a detail you want to find out later.

“It’s more swollen than yesterday. Is it ruined?”

Day three, most often. A knee that’s warm and full, range down, and a patient who has decided this means failure.

It’s a needle through a joint capsule. Of course it reacts. That part settles.

The call that surprises people is the second-week one — swelling arriving after they’d relaxed, which frightens them more than the early kind because they thought the danger had passed. It’s common. We warn about it now; we didn’t use to, and the 2am searches were our own fault.

What I’d want to hear about same-day: swelling that keeps climbing after day five. A joint hot and red with fever past 38°C. Pain that stops you bearing weight at all. Those aren’t forum questions.

“When can I go back to the gym?”

An engineer asked me this in March. I said gentle movement. He heard a number, rode a stationary bike for fifty minutes on day two, and came back with a knee like a melon. He wasn’t reckless. “Gentle” was the useless word.

So, concretely: walking from day one if it’s comfortable. Easy cycling in the first week if the knee tolerates it. Swimming once the needle site is shut. Light work on the surrounding muscle from about week two — and only if the next morning is quiet.

Impact is last and it’s slow. Running, jumping, court sports, loaded squats: six to twelve weeks, sometimes never for a knee that was already degenerate before anyone injected it. That’s the joint’s arithmetic, not the treatment’s.

One rule survives every schedule: swelling still there next morning means you overdid it, and you drop back a step.

“I flew home and now it feels worse. Did the flight do something?”

Probably not the flight. Probably the eleven hours sitting still with a swollen knee folded under an airline tray table.

Aisle seat, walk the cabin hourly, and wear the compression stocking you were given and were planning to leave in the room. If your protocol was intravenous rather than into a joint, ask about flying restrictions before you buy the ticket — a few protocols carry them, and it’s the kind of thing that falls between the invoice and the departure gate.

If you want the shape of the whole week in Bangkok, rest days included, that’s in our piece on recovery week in Bangkok.

“Nothing has changed. Was it a waste of money?”

Week three, almost always. And the truthful answer is that week three tells you very little.

Joint injections frequently feel worse before they feel better. The changes patients actually describe are counted in months, and the ones who report a dramatic fortnight are, in my experience, reporting the steroid some clinics add to the mixture rather than the cells. We don’t add it. Which means our patients get the slower, less flattering version of the story.

Intravenous patients get a different wrinkle: a mild temperature and a washed-out day or two, usually passing by itself. Fever that climbs, or comes with rigors, breathlessness or a rash, is urgent and not the ordinary reaction.

I’d rather say all this at the start than have someone conclude on day ten that they were cheated. Some patients do fail to respond — that’s a real outcome, not a marketing problem — and deciding whether a second round is worth paying for is its own conversation. If you’re weighing that up, or still planning the first one, the team will talk it through honestly through the contact form on the home page.

And if something feels wrong at the injection site, or there’s numbness, or a fever in the first 48 hours after an infusion, call. We are not irritated by the early calls. We are irritated by the day-nine ones.