Reading Your Wrist and Carpal Bone Imaging

The Imaging Sequence After a Fall on an Outstretched Hand

A wrist that hurts after a fall almost always gets a four-view radiograph series first: PA, lateral, and oblique projections plus a dedicated scaphoid view taken with the wrist angled and the hand in ulnar deviation to stretch that bone out of its foreshortened resting position. That scaphoid view exists because the bone sits at an angle across the radial column, and a fracture line running along its waist can hide inside the overlap on a standard PA film.

Even with the dedicated view, a non-displaced scaphoid waist fracture is one of the most commonly missed injuries on day-one imaging, because the fracture line can be too fine to resolve before localized bone edema develops. When tenderness sits squarely in the anatomical snuffbox but the first films read clean, the standard practice is either a short course of splinting and a repeat film in ten to fourteen days, once bone resorption along the fracture edges has widened it enough to see, or an MRI sooner if waiting isn't acceptable. Ligament and TFCC questions get answered with MRI or, when a partial tear needs confirming, an MR arthrogram that injects contrast directly into the joint to outline a tear the surrounding fluid would otherwise mask. When a scaphoid fracture has already been treated and the question shifts to whether it has healed, a CT angled along the long axis of the scaphoid gives the clearest look at bridging bone across the fracture line, which a plain film can suggest but rarely confirms on its own.

What the Consortium Traces Through a Carpal Study

Once a wrist series is rendered, the four-model panel steps through each carpal bone individually — scaphoid, lunate, triquetrum, pisiform, trapezium, trapezoid, capitate, and hamate — checking cortical continuity, the Gilula arcs that describe normal carpal alignment on a PA film, and the scapholunate and lunotriquetral intervals for widening. On MRI series the same models trace the intrinsic carpal ligaments, the TFCC, and the tendon sheaths crossing the wrist for signal changes that suggest tenosynovitis or a partial tear, then reconcile disagreements across models before producing a combined read.

The plain-language wrist report turns carpal shorthand into something a patient can actually use: instead of “scapholunate interval widened to 4mm, Terry Thomas sign present,” it explains that the ligament holding two of the wrist bones together has stretched or torn enough that a gap has opened between them on the X-ray, and why that particular gap tends to need a hand surgeon's opinion rather than a wait-and-see approach. The aim is orientation before a specialist visit, not a replacement for the visit itself.

The Six Clusters Behind Most Wrist Referrals

Distal radius and scaphoid fractures make up the largest single group, usually from a fall onto an outstretched hand, and range from a simple non-displaced scaphoid waist crack to a comminuted distal radius fracture with dorsal angulation that needs surgical fixation. Carpal ligament injury and instability center on the scapholunate and lunotriquetral ligaments, where a sprain can progress over months into a widened interval and, eventually, a predictable pattern of carpal collapse if it goes unrecognized. Ulnar-sided wrist pain and TFCC problems cluster around the small triangular cartilage disc that cushions the ulnar side of the joint, often aggravated by a twisting or loading motion such as opening a jar. Tendon and nerve compression syndromes cover carpal tunnel syndrome pressing on the median nerve, De Quervain tenosynovitis irritating the thumb-side tendons, and intersection syndrome where two tendon compartments rub against each other. Degenerative and inflammatory arthritis shows up as joint-space narrowing and osteophytes at the base of the thumb or across the radiocarpal joint, sometimes following an old untreated scaphoid nonunion pattern called SNAC wrist. Avascular necrosis of the lunate, known as Kienböck disease, is its own distinct entry, where the lunate bone gradually loses its blood supply and collapses over months to years, visible on MRI long before it shows up on a plain film.

Turning a Wrist Report Into Next Steps

If a report names a specific carpal bone or ligament — scaphoid, lunate, TFCC, scapholunate — the matching condition page above breaks down how that finding typically presents on X-ray, CT, and MRI, and what usually happens next. If you are starting from the DICOM series rather than a written report, the free wrist viewers let you scroll through the same PA, lateral, and oblique frames a radiologist would review before you send anything through the analyzer. Carrying both the original images and the plain-language summary into a hand and wrist specialist appointment tends to shorten that conversation considerably.