Delayed pains post-injury – or latent pain – seem quite common and can be hard to integrate clinically. You can never really be sure that a latent pain is entirely attributable to the activity a person believes it is. The key thing for me is that although the term ‘latent pain’ sounds a bit scary – as though it could strike any time – it is actually so common that it’s quite normal. In this way, it can be used as an education tool to demonstrate that pain rarely relates to the amount of damage.
I read about another latent pain example to add to the Explain Pain toolbox – that of pain post-THR (total hip replacement) (Greimel at al 2018 Arch Orthop Traum Surg 136:1639). Most studies measure pain months after an incident or intervention. This study is a bit unusual in that pain levels (Numerical Rating Scale) were recorded 4 times a day for 4 weeks post surgery. In this THR group, pain decreased post-surgery then around 9 days it peaked for 3 days before easing off again. The authors noted that it appeared to be related to the onset of intensive rehabilitation. This may be the case, though temporal fluctuations in immune activity could be another reason.
This is quite a nugget. You could say to the total hipsters “yes, there is some research showing that it’s quite normal to get a bit more pain even 9 days after the event”. I would probably add something like – “it shows you are alive” and “it tells you the surgery is over” and at the appropriate moment, that “your hip is fine”. To the credit of the authors, they suggest this finding should be a part of education, not the usual suggestion of just upping the pain meds. Lorimer Moseley and I discussed latency in more detail in the Novella ‘Pain on Hold’ in Explain Pain Supercharged (2017).