In most areas of medicine, and certainly orthopedics, common problems present commonly.  A relatively finite number of diagnoses make up the majority of what we see.  Through experience, we develop heuristics, or “mental shortcuts” which through pattern recognition, allow us to relatively efficiently arrive at a diagnosis, or set of potential diagnoses.  One of the challenges in hand surgery, and all of medicine, is when a patient falls outside of that for which we have a heuristic.  Such was the case of the following patient.

The patient is a 42 year old, right hand dominant female who presented with 4 years of vaguely localized pain over the distal 25% of her forearm.  She was unable to clearly sense if it was more volar or dorsal.  Described a motor vehicle collision a couple months before the onset of her symptoms which she think may be related, but no immediate pain following the accident.  The last 2 years have been particularly bothersome and she feels symptoms are getting worse.  She describes increasing “wrist stiffness” and symptoms are midly worse after activity, but not with any specific activities.  She denies any associated symptoms including numbness, tingling, nocturnal parasthesias or awakenings.

Her medical history is significant for a well controlled seizure disorder managed with a single medication which she has taken for several years.  She works as a police officer.

Physical Exam:

  • Moderate circumferential swelling right wrist
  • Vague diffuse tenderness to palpation centrally, over volar and dorsal wrist ~3-6 cm proximal to wrist crease. Particularly volarly
  • Digital ROM: Full
  • Pronation: Full bilaterally
  • Supination
    • Right: 0                  Left 90
  • Loss of ~15 degrees wrist flexion on right
  • DRUJ stable, no tenderness

Initial XRs

Although not a perfect lateral, I noted some dorsal displacement of the ulnar head and decided to get a CT to better evaluate the DRUJ relationship.  In hindsight, a closer inspection of the initial XRs does show some subtle cortical irregularity to the ulnar side of the radius.

CT

While the CT didn’t demonstrate any obvious DRUJ abnormalities, there was noted to be “fatty infiltration” of the pronator quadratus and an MRI was ordered.  While the CT report attributed the cortical thickening to healed fractures, the patient was unaware of any previous fractures to her wrist.

MRI

 

 Even with the presence of the mass, I wasn’t sure if this was the cause of her symptoms, both the aching pain and the loss of supination or simply “true-true unrelated.”  After discussion however, it was jointly decided to excise the AVM.

INTRAOP

 Patient was examined pre-operatively and had full pronation and a firm block to supination at neutral.

 

 

Post-operatively, patient had immediate correction of her supination defect and could easily be supinated to 90 degrees without resistance.

Discussion

This was a very instructive case for me because it served as a reminder that just because someone’s symptoms fall outside of your heuristics, doesn’t mean they don’t have real pathology.  I wish I could say that I ordered the initial CT to rule out the possibility of an unrecognized mass or tumor, but I really didn’t – I was really looking to evaluate the DRUJ.  Common things happen commonly and uncommon things happen uncommonly, but this case reinforces to me the need to think broadly, expand the differential diagnosis when a patient’s symptoms fall outside of patterns and diagnoses that we are used to seeing.