Louis Mamode

Louis Mamode: FCP portfolio case study

A limb/life-threatening presentation in primary demonstrating clinical excellence by a first contact podiatrist

A case of an undiagnosed DVT with a normal D-dimer result

Clinical presentation 

Patient X was referred by his GP presenting with unilateral foot pain that had been present for 10 weeks. He presented with swelling and redness of the lower leg. The pain was located in the plantar metatarsal area and was worse on weight-bearing and palpation of his second and third metatarso-phalangeal joint (MTPJ) area. The patient did not report any trauma to this area and reports the pain gradually increases to the point where he is now unable to weight-bear for longer than an hour on his foot. Pain is not isolated to this area and can move proximally along the calf muscle. This is intermittent.

Previous assessments and tests

He had a recent D-dimer test which was normal.

Clinical tests and imaging 

I suspected this still might be a DVT, I carried out the Wells' Score which was 3 with positive scores including calf swelling >3cm compared to contralateral side, unilateral leg swelling and unilateral pitted oedema.

I discussed this with my duty GP and arranged a duplex ultrasound which detected a femoral vein embolism, confirming the presence of a DVT. The patient was prescribed Rivaroxaban.

Differential diagnoses and your clinical reasoning

Differential diagnoses could include fractured metatarsal heads, capsulitis, and plantar plate tear which may have been suspected due to his location of foot pain. His X-ray also revealed lucency over the MTPJ area when compared to previous X-ray images taken 2 years earlier, osteopenia or osteoporosis, osteomyelitis or malignancy were possible differentials leading to loss of bone density, however this was only visible around the MTPJ and was not reported on the X-ray and may have been an artefact.

My clinical skills and history taking led me to believe the gentleman presented with atypical musculoskeletal symptoms and increased my suspicion of DVT despite a normal D-dimer result.

My reflection

I learnt that a normal D-dimer does not exclude the possibility of DVT and that strong celinical suspicion as well as a high Wells' Score warrants further investigation and referral to the vascular team.

This has impacted my practice as I will now incorporate the Wells' Score for any unilateral lower limb swelling and foot and ankle pain.