Hi!
Tough timeframe - most people on this forum don't reply too often!
Put simply, a costochonral junction injury would have a step in it and a contusion won't - it will have a bump from the fluid trapped in the fascia. But I don't think that will be enough to pass your exam! :rollin !
I'll try help as best I can but I left my textbooks at work - "The Thorax" by Diane Lee (www.dianelee.ca) is excellent, even though a bit dry at times. One good thing I learnt from Diane and LJ Lee is that the thorax is like 12 little pelvis'! You think just the pelvis is hard! Try 12 individual thoracic assessments! There are up to 13 joints at each thoracic ring!
Bascially - is it a costochonral junction pain? It's not costosternal, costovertebral, costotransverse, etc but costochondral?
I ask because the joint mechanics of each of the above can affect the chostochondral junction. If this were my patient, I would first get his history, get where his pain is, assess the T/S vertebrae, clear the L/S and C/S, then check the ribs.
T/S - transverse processes - are they symmetrical or are some more posterior than others. In neutral, the coupled movements of the T/S vertebrae are rotation and contralateral sideflexion. So if the right lateral flexors are tight, you will see the vertebra rotate to the left. In flexion and extension, coupling is ipsilateral so tight right sideflexors mean lateral flexion and rotation to the right. Rx would be to clear the type I dysfunctions first (multilevel rotations to the same side in neutral) and then reassess for Type II (F/E dysfunctions).
Ribs - in flexion of the T/S, the ribs rotate inferiorly and anteriorly (??). In extension, they rotate posteriorly and superiorly (??). At ribs 7-10, they move ALI (anteriorly, Laterally and Inferiorly) and PMS (Posteriorly, Medially and superiorly). I am pretty sure that is right but i don't have my textbooks to be certain! Palpate the rib angles on the posterior chest wall to see if they are sticking out compared to the other side. The rib dysfunctions could be superior, inferior, AP, lateral compression joint fixations. You could then also get rib torsions which result from myofascial tightening of tissue around chronic problems - may not be the case in your guy - but then he may have had a chronic problem that got pushed over the edge with the accident!
As for the costochonral junction - it should feel symmetrical without any steps in it. Is there pain in breathing? Are the ribs splinted together by the intercostal muscles?
Don't forget the obliques and serratus extend over a significant portion of the anterior thorax and could also have an effect.
The Single-Arm Lift (LJ Lee) is like the Active SLR which is also good for helping to diagnose dysfunctions. If he finds his symptomatic side to be hard to lift, support the injured rib and get him to lift again - if it is easier, then he has a stability problem and motor control training would need to be done.
I would say that if everything comes up as fairly symmetrical in examination and joints are normal and muscles are negative, then he probably has a rib contusion and you would feel it on the rib.
Long term management would be restoration of ROM and arthrokinematics of the affected segments, stability training of the multifidus and rotatores progressing onto intergration with ADLs and global muscle use (think hodges, hides, richardson, jull, o'sullivan, commerford etc), etc.
Short term would be resotration of painfree ROM and isolating core stabilisers. Taping also works well.
I hope this helps!