Wrist Arthrogram

Anatomy and Physiology

Bony Structures of the Wrist 

The wrist joint is formed by the articulation between the distal end of the radius and the articular disk with the proximal carpal row (excluding the pisiform). The carpal bones create a convex surface that matches the concave configuration of the distal radius and articular disk.[3] The distal ulna does not articulate directly with carpal bones due to the presence of the articular disk. The distal radioulnar joint articulates the distal ulna with the distal radius.[4]

Ligaments of the Wrist

The ligamentous attachments of the wrist are crucial for maintaining stability and facilitating coordinated movements.[5] There are 4 main ligaments situated at the wrist joint, each serving distinct functions:

• Palmar radiocarpal ligament: located on the volar aspect extending from the radius to both rows of carpal bones. This ligament enhances stability and ensures the synchronization of hand and forearm movements during supination.
• Dorsal radiocarpal ligament: runs from the radius to both carpal rows on the dorsal aspect of the wrist, contributing to wrist stability and coordinating hand and forearm motions during pronation. 
• Ulnar collateral ligament: extending from the ulnar styloid process to the triquetrum and pisiform, effectively preventing excessive radial deviation of the hand.
• Radial collateral ligament: connecting the radial styloid process to the scaphoid and trapezium, inhibiting excessive ulnar deviation.[3]

Triangular Fibrocartilage Complex

The triangular fibrocartilage complex (TFCC) contributes significantly to the stability of the distal radioulnar joints. The TFCC is positioned on the ulnar aspect of the wrist between the ulna and the lunate and triquetrum of the proximal carpal row. The TFCC has an elongated triangular shape with its apex directed towards the radius.[6] The TFCC comprises various ligamentous and fibrocartilaginous components, including the triangular fibrocartilage disc proper and triangular ligament, volar and dorsal radioulnar ligaments, ulnocarpal ligaments (ulnotriquetral, ulnolunate, ulnocapitate), meniscal homologue, ulnar collateral ligament, and the extensor carpi ulnaris tendon sheath.[7] Functionally, the TFCC stabilizes the distal radius ulnar joint, cushions the ulnar carpus, accounts for 20% of axial wrist load, and is a crucial stabilizer for the ulnar carpus.[8][9]

Indications

The indications of performing a wrist arthrogram, whether conducted as a single investigation or in a combination of other imaging modalities, include but are not limited to:

• Diagnosis of wrist joint degenerative and inflammatory conditions such as osteoarthritis and rheumatoid arthritis 
• Identification of traumatic ligamentous abnormalities in the scapholunate ligament, lunotriquetral ligament, and TFCC [10][11]
• Assessment of wrist joint articular cartilage for osteochondral defects [12]
• Investigation of persistent wrist pain [13]
• Suspected scaphoid fracture nonunion [14]
• Assessment for ulnar abutment [15]

Contraindications

A wrist arthrogram is generally a well-tolerated diagnostic procedure. However, there are certain contraindications that clinicians should consider before recommending or performing wrist arthrograms. These contraindications include: 

Absolute Contraindications

• Previous allergic reactions to contrast material: A known allergy to the contrast material (usually iodine-based contrast agents) used in the arthrogram should preclude the procedure.
• Presence of an active infection: An active infection around the wrist joint can spread. For example, injecting contrast material through infected skin can lead to septic arthritis due to the deeper spreading of the infection.

Relative Contraindications

• Renal dysfunction: Patients with significant renal dysfunction may be at risk for contrast-induced nephropathy. The contrast dose needs to be adjusted accordingly.
• Coagulopathies: Individuals with bleeding disorders or those taking anticoagulant medications may be at an increased risk of bleeding complications during or after the arthrogram. In such cases, careful consideration and potential modification of medication regimens may be necessary.
• Uncontrolled diabetes: Uncontrolled diabetes may increase the risk of contrast-induced complications, and healthcare professionals may need to assess and manage the patient's diabetic status before proceeding with the arthrogram.
• Pregnancy: Pregnancy is generally considered a relative contraindication, and the risks and benefits of the procedure must be carefully weighed. Radiation exposure from imaging studies, such as x-rays, should be minimized during pregnancy.

Before recommending a wrist arthrogram, healthcare professionals must thoroughly assess the patient's medical history, current health status, and potential contraindications. In cases where contraindications are present, alternative diagnostic approaches or modifications to the procedure may be considered to ensure patient safety.

Equipment

The equipment required for performing a wrist arthrogram includes the components for injection of the local anesthesia and the contrast material into the wrist joint. This includes: 

• Sterile drapes
• Local antiseptic solutions
• Blunt wide bore needle to withdraw the local anesthesia and contrast solutions
• Sharp fine needle to access the joint for injections
• 3-mL syringes for contrast solution injection
• 10-mL syringe for the local anesthetic solution preparation and injection
• Contrast agents, gadolinium or iodine-based

Due to its fast-acting anesthetic effect, 1% lidocaine is commonly used for local anesthesia. Lidocaine can be combined with a sodium bicarbonate solution as a buffering agent to minimize irritation caused by the acidic nature of the local anesthetic; this can be achieved by adding approximately 0.5 mL of sodium bicarbonate to 10 mL of 1% lidocaine. An emergency resuscitation cart should be accessible for use in case of an anaphylactic reaction to any of the injected materials.

Technique or Treatment

Informed consent must be obtained before performing wrist arthrography, and contraindications such as infection and contrast allergies should be ruled out before beginning the procedure. The patient is positioned supine on a fluoroscopy table with the wrist in a neutral position. The skin over the wrist is prepped with antiseptic, and an aseptic technique is employed to inject contrast. The injection is ideally performed from the side opposite to the wrist symptoms. For example, injection from the lateral side of ulnar wrist pain allows better differentiation between iatrogenic contrast leakage and leakage due to a capsular tear. Typically, contrast is injected into the joint under imaging guidance, often using an image intensifier.[15]

Wrist arthrography can be performed for 1 compartment (radiocarpal), 2 compartments (radiocarpal and midcarpal or radiocarpal and distal radioulnar), or more commonly for 3 compartments (radiocarpal, midcarpal, and distal radioulnar compartments).[16][17] To inject contrast into the midcarpal compartment, the space between the scaphoid and capitate or between the triquetrum and hamate is targeted. This allows contrast to flow into the scapholunate and lunotriquetral spaces. If the intrinsic ligaments between the scaphoid, lunate, and triquetrum are intact, the contrast will not flow into the radiocarpal joint. For contrast injection into the radiocarpal compartment from the ulnar side, the target is the space between the radial side of the pisiform and the proximal triquetrum. Injection from the radial side involves the space between the styloid process and the proximal pole of the scaphoid. The radial margin of the ulnar head is targeted to inject the distal radioulnar joint.[15]

Complications

Complications associated with wrist arthrogram may include:

• Allergic Reactions
  • Some patients may develop allergic reactions to the contrast material used in the procedure. This is more common with iodine-based contrast agents.
  • Adverse allergic reactions can range from mild skin irritation to severe anaphylaxis.
• Septic Arthritis
  • There is a risk of introducing an intraarticular infection during the wrist arthrogram, particularly if aseptic techniques are not followed.
  • Infections can present as local swelling, redness, pain, and systemic symptoms such as fever and sepsis.
  • If the diagnosis of septic arthritis is confirmed, an urgent surgical wrist joint washout is mandatory to preserve the joint cartilage and prevent systemic sepsis. 
• Bleeding: Bleeding at the injection site or within the joint may occur, especially in individuals with bleeding disorders or those taking anticoagulant medications. Clinicians may consider the benefits and risks of stopping anticoagulant treatment before wrist arthrogram. 
• False-Positive Findings: Accidental gas injection during the performance of a wrist arthrogram can result in a false-positive diagnosis of loose intraarticular bodies, leading to misinterpretation of the diagnostic imaging results.
• Sterile Chemical Synovitis
  • Postarthrography pain, often resulting from sterile chemical synovitis, is the most common complication of wrist arthrography.
  • The introduction of contrast material causes an inflammatory reaction within the wrist joint. Symptoms typically begin about 4 hours postprocedure and peak at around 12 hours. Despite the absence of infection—hence the term "sterile"—the contrast agent's chemical irritant properties can inflame the synovial lining, causing pain, swelling, and discomfort.
  • This complication can mimic septic arthritis, requiring close monitoring and management by healthcare professionals to ensure accurate diagnosis and treatment.[18]
• Nerve or Vascular Injury: In rare cases, the needle used for the injection may inadvertently damage nearby nerves or blood vessels, leading to neurological or vascular complications.
• Intraarticular Structures Damage: There is a small risk of causing damage to the joint structures during the injection, particularly if there are preexisting joint abnormalities or pathology.
• Pain or Discomfort: Some patients may experience temporary pain or discomfort at the injection site or within the joint, usually mild and short-lived.
• Radiation Exposure: If x-rays are used during the procedure, there is potential for radiation exposure. While the amount of radiation is generally low, it is a consideration, particularly for pregnant patients. Healthcare professionals should take the necessary precautions to minimize risks and follow safety protocols.

Clinical Significance

The wrist arthrogram is a valuable diagnostic tool for evaluating intraarticular pathology and structural abnormalities within the wrist joint, including:

TFCC Tears

The TFCC serves as a critical stabilizer for the lunate, triquetrum, and ulnar head while also functioning as a load-bearing structure on the ulnar side of the wrist. Injuries to the TFCC are commonly associated with activities that involve forced ulnar deviation or positive ulnar variance. Such injuries often occur when pressure is applied to the TFCC during wrist movements like wielding a racket, swinging a bat, or in cases of trauma such as falling on an outstretched hand or hyperextension injuries.[9][10][19]

Conventional MRI scans can struggle to differentiate between degenerative and traumatic TFCC tears due to their limited sensitivity and specificity.[20][21][22] However, combining MRI with an arthrogram (MR arthrography) significantly enhances diagnostic accuracy, with reported sensitivity and specificity rates of 97.1% and 96.4%, respectively, for identifying partial and complete TFCC tears.[23] In MR arthrography, TFCC perforations appear as areas of high signal intensity on fat-suppressed T1-weighted images, and contrast material may also be visualized in the distal radioulnar joint in cases of traumatic TFCC injury.[24]

Scapholunate Ligament Injury and Scapholunate Instability

Scapholunate ligament injury has the highest incidence of wrist ligament injuries. In advanced cases, injury of the scapholunate ligament can result in progressive scaphoid flexion, widening the articulation between the scaphoid and lunate bones in wrist anteroposterior radiographs. If a single compartment arthrogram is performed for the radiocarpal compartment and the contrast is identified in the midcarpal compartment, this is a sign of scapholunate ligament disruption. MR arthrography is more sensitive than MRI for detecting scapholunate ligament injuries' exact location and extension.[15]

Midcarpal Instability

These rare injuries involve disruption of the ligaments between the distal and proximal carpal row bones while the proximal row ligaments stay intact. MR arthrography has higher sensitivity in assessing each ligament and the exact extension of injury.[15]

Distal Radioulnar Joint Abnormalities

The wrist arthrogram allows further assessment of articular cartilage at the distal radioulnar joint and the joint capsule for any signs of tears or synovitis.[25]

Enhancing Healthcare Team Outcomes

Performing and interpreting a wrist arthrogram involves a collaborative effort among healthcare professionals, necessitating a spectrum of skills, strategic planning, ethical considerations, shared responsibilities, effective interprofessional communication, and meticulous care coordination to optimize patient-centered care, enhance outcomes, ensure patient safety, and improve team performance. Physicians must comprehensively understand wrist anatomy, pathology, and the diagnostic implications of wrist arthrogram. Advanced clinicians, including radiologists, need specialized skills in performing the procedure, ensuring accurate contrast injection, and interpreting imaging results. Nurses are crucial in preparing patients for the arthrogram, providing care before and after the procedure, and monitoring potential complications. Pharmacists contribute by ensuring appropriate contrast agents and medications and managing drug-related concerns.

Ethical considerations involve obtaining informed consent, ensuring patient privacy, and communicating clearly about the procedure and potential outcomes. Team members share responsibilities, with each professional contributing expertise to the overall patient care plan. Interprofessional communication is paramount to ensure that all team members are aligned in understanding the patient's condition, the purpose of the wrist arthrogram, and the subsequent care plan. This collaborative approach helps address concerns, share critical information, and foster a cohesive team dynamic. Care coordination involves scheduling appointments, communicating results among team members, and ensuring that the patient receives appropriate follow-up care, which is essential for a seamless patient experience. This coordinated effort enhances patient-centered care, contributes to positive outcomes, and reduces the risk of errors or oversights.