Help with diagnosis please..
I recently (2 days ago) saw a patient (around 30 y/o) who c/o pain in the area of the navicular tuberosity, palpable over an area of about 1cm diameter and around the cuboid (very specific point on the plantar aspect) in the left foot.
The pain started after the gentleman put his forefoot onto a stair to start ascending, and as he put his foot down he heard (or rather felt) something click deep in the arch and on the outside (lateral border) of his foot. The immediate sensation was one of discomfort... that it felt like it needed to "click" again to go back into place. However over the following 3.5 years the pain has gradually increased until it is now at a point where it is literally debilitating him. He reports that the pain is constant, keeps him awake at night and is severe in the morning, after rest and after activity. He feels he has no strength in the ankle and walking on uneven ground is particularly difficult. The pain has, on occasion when the knee has “buckled”, reduced him to tears.
He is able to stand on tip toes on the pathological leg, with a little discomfort, but nothing approaching the pain felt in gait. Muscle testing of the lower leg shows nothing particularly obvious, and active and passive movement of the leg in open chain does not recreate Gait-like symptoms.
There are no particular red flags in his medical Hx, no illnesses, injuries or any other episodes that the gentleman can recall with the exception of when he was in school and used to play football a lot, the area around the navicular on the medial aspect of the foot has ached a couple of times after kicking a ball particularly hard, although this was well over 10 years ago.
He has had investigations and interventions from a range of practitioners, including physio, casted and off the shelf insoles from podiatrists (neither of which he could tolerate as the arch area of the insole aggravated the painful area in the MLA) and surgery for a suspected osteoid osteoma in the styloid process.
X-ray shows accessory bones in both feet around the groove for the peroneus longus at the cuboid, it shows narrowing of the joint space in the articulation between navicular and cuneiform on the left foot, and there appears to be an exostosis or calcification around the navicular process on both feet but with L being much more pronounced than right.
When observing the patient walking, the lowering of the left forefoot to floor immediately after heel strike is very tentative and during forefoot loading if the navicular drops by more than "x" amount or reaches this point too quickly it causes great pain and causes him to very quickly bend at the knee, giving the appearance that the knee is buckling.
I tried some tib post rest strapping and this greatly reduced the pain in the medial aspect of his left foot and he feels that it gave him a lot more confidence and strength in the foot. The pain in the lateral aspect of the foot is unchanged.
I have some DDx and a tentative treatment plan, but just wanted a little input before I continue.