Courtesy: Prof Abhijeet Wahegaonkar, Sancheti Hospital, Pune, India

Wrist Arthroscopy, Indications and Techniques

 

Overview

• Wrist arthroscopy is a minimally invasive technique that allows direct visualization and treatment of disorders affecting the wrist.
• It belongs to the broader field of small-joint arthroscopy, which also includes arthroscopy of the thumb, metacarpophalangeal joints, interphalangeal joints, foot and ankle, and temporomandibular joint.
• Improvements in optical systems, cameras, and miniature instruments have significantly expanded the diagnostic and therapeutic applications of wrist arthroscopy.
• The technique can provide high-resolution visualization of the joint and allows procedures to be performed through small portals with limited disruption of surrounding soft tissues.

Why Wrist Arthroscopy Is Useful

• Wrist arthroscopy can be used for both diagnosis and treatment.
• Direct visualization may help identify pathology that is difficult to evaluate through clinical examination and conventional imaging alone.
• The arthroscopic probe functions much like an extension of the surgeon’s finger, allowing assessment of:
  • Cartilage consistency and surface abnormalities.
  • Ligament tension and stability.
  • Joint congruity.
  • Articular surface irregularities.
  • Reduction of fracture fragments.
  • Articular step-offs.
• The technique has evolved considerably and is now used for a wide range of soft-tissue, ligament, cartilage, and bone conditions.

Equipment and Instrumentation

• Wrist arthroscopy requires smaller and more delicate equipment than many large-joint arthroscopic procedures.
• Commonly used equipment includes:
  • A small-diameter arthroscope, commonly 1.9 or 2.9 millimeters in diameter.
  • A 30-degree viewing angle, with wider-angle scopes available for selected applications.
  • A blunt trocar and cannula to reduce the risk of cartilage injury during entry.
  • A small arthroscopic probe.
  • Basket and grasping forceps.
  • Fine haemostatic or hemostat forceps.
  • A small scalpel blade for portal creation.
• Small shavers, burrs, and radiofrequency instruments can be added when more advanced therapeutic procedures are required.
• Modern high-definition optical systems have substantially improved visualization compared with earlier arthroscopic equipment.

Patient Positioning and Joint Distraction

• The patient is generally positioned supine on the operating table.
• Wrist arthroscopy can be performed under regional or general anesthesia, depending on the procedure and clinical circumstances.
• A tourniquet may be used when appropriate.
• The shoulder is commonly abducted to approximately 90 degrees and the elbow flexed to approximately 90 degrees.
• Unlike many arthroscopic procedures in which joint space is created primarily through fluid distension, wrist arthroscopy commonly uses controlled traction or distraction.
• Finger traps, hand holders, or specialized traction systems can be used to apply distraction.
• Distraction creates sufficient working space within the wrist and facilitates visualization and instrumentation.
• The amount of traction should be carefully controlled to avoid unnecessary soft-tissue or nerve-related complications.

Arthroscopic Portals and Surface Anatomy

• Knowledge of wrist surface anatomy is essential for safe portal placement.
• Most commonly used wrist arthroscopy portals are located dorsally in relation to the extensor tendon compartments.
• Portal names are generally based on their relationship to the extensor compartments.
• Common portals include:
  • 3–4 portal.
  • 4–5 portal.
  • 6R portal.
  • 6U portal.
  • Radial midcarpal portal.
  • Ulnar midcarpal portal.
• The 3–4 portal is positioned between the third and fourth extensor compartments.
• The 4–5 portal lies between the fourth and fifth extensor compartments.
• The 6R portal is positioned immediately radial to the sixth extensor compartment.
• Additional portals can be used according to the pathology and the specific procedure being performed.

Important Anatomical Landmarks

• Careful identification of surface landmarks helps reduce the risk of injury to tendons, nerves, and other soft tissues.
• Lister’s tubercle is an important palpable bony landmark on the dorsal distal radius.
• The distal radius, ulnar styloid, extensor tendons, and metacarpal bases can be identified before portal placement.
• The soft-tissue interval around the wrist can then be used to determine the appropriate portal location.
• After making a small skin incision, blunt spreading rather than deep sharp dissection helps protect underlying structures.

Access to the Wrist Compartments

• Arthroscopy can provide access to several wrist compartments, including:
  • Radiocarpal joint.
  • Midcarpal joint.
  • Distal radioulnar joint.
  • Selected carpometacarpal joints.
• The choice of portal depends on the compartment being examined and the pathology being treated.
• Accurate portal placement is particularly important because the wrist contains closely packed tendons, ligaments, nerves, and vascular structures.

Diagnostic Arthroscopy

• A systematic examination helps minimize the possibility of overlooking pathology.
• A commonly used sequence is:
  • Examination of the radiocarpal joint.
  • Examination from the radial side toward the ulnar side.
  • Assessment from distal to proximal.
  • Examination of palmar and dorsal structures.
  • Evaluation of ligaments and cartilage.
• Although there is no single mandatory sequence, following a consistent examination pattern improves the reliability of diagnostic arthroscopy.

Radiocarpal Joint

Important structures that may be evaluated include:

• Distal radius.
• Scaphoid fossa.
• Lunate fossa.
• Scapholunate ligament.
• Triangular fibrocartilage complex.
• Radiocarpal ligaments.
• Cartilage surfaces.
• Synovial tissue.
• Dorsal and palmar portions of relevant ligamentous structures.

Midcarpal Joint

The midcarpal examination allows assessment of:
• Scaphoid.
• Lunate.
• Triquetrum.
• Capitate.
• Hamate.
• Scapholunate ligament.
• Lunotriquetral ligament.
• Other intrinsic and extrinsic ligamentous structures.
• Carpometacarpal joint relationships.

Major Therapeutic Applications

The therapeutic role of wrist arthroscopy has expanded substantially. Important applications include:

• Triangular fibrocartilage complex injuries.
• Intrinsic ligament injuries.
• Distal radius fractures involving the joint surface.
• Scaphoid fractures.
• Scaphoid non-union.
• Ganglion cyst excision.
• Ulnocarpal impaction syndrome.
• Selected procedures for wrist arthritis.
• Synovectomy and debridement.
• Selected reconstructive and stabilizing procedures.

Triangular Fibrocartilage Complex Injuries

• Arthroscopy allows direct assessment of the triangular fibrocartilage complex and helps determine the location and characteristics of a tear.
• A probe can be used to evaluate the stability of the tissue and identify peripheral tears.
• Arthroscopic treatment may include debridement or repair depending on the tear pattern, tissue quality, and associated instability.
• Peripheral tears may be treated with arthroscopic capsular or ligamentous repair techniques.
• Tears involving the foveal attachment may require reinsertion of the triangular fibrocartilage complex to its anatomical attachment using appropriate fixation methods.
• Successful repair aims to restore the stability of the distal radioulnar joint when instability is present.

Scapholunate Ligament Injuries

• Arthroscopy provides direct assessment of the scapholunate ligament from both the radiocarpal and midcarpal compartments.
• The extent of ligament injury and the condition of the remaining tissue can be evaluated using a probe.
• Selected ligament tears can be treated with arthroscopic repair techniques.
• Depending on the injury pattern, sutures may be passed through the remaining ligamentous tissue and capsule to restore the relationship between the scaphoid and lunate.
• Temporary fixation may sometimes be used to protect the repair while healing occurs.
• Treatment is individualized according to the stage and severity of instability.

Distal Radius Fractures

• Arthroscopy can assist in the management of fractures extending into the wrist joint.
• It is particularly useful when accurate restoration of the articular surface is important.
• Arthroscopic visualization can help:
  • Assess the joint surface.
  • Improve fracture reduction.
  • Identify residual articular incongruity.
  • Detect associated ligament or triangular fibrocartilage complex injuries.
  • Confirm implant position.
• Arthroscopy may therefore complement minimally invasive fracture fixation rather than replace conventional fixation techniques.

Scaphoid Fractures

• Selected scaphoid fractures can be reduced and stabilized using minimally invasive techniques assisted by arthroscopic visualization.
• Arthroscopy allows direct assessment of fracture reduction and fixation.
• It can help identify whether a screw is appropriately positioned and whether any portion of the implant projects into the joint.
• Preserving the surrounding soft-tissue envelope may be beneficial when performing minimally invasive fixation.

Scaphoid Non-union

• Arthroscopic techniques can be used in selected cases of scaphoid non-union.
• Bone grafting may be performed through a small portal under arthroscopic visualization.
• Cancellous bone graft can be introduced into the non-union site and carefully packed into the defect.
• Care is required to prevent graft material from entering the joint.
• After grafting, the scaphoid can be stabilized using appropriate percutaneous fixation when indicated.
• Patient selection is important because not all patterns of scaphoid non-union are suitable for arthroscopic treatment.

Ulnocarpal Impaction Syndrome

• Arthroscopic distal ulna resection can be considered in selected patients with ulnocarpal impaction.
• The objective is to reduce excessive contact between the ulna and the carpus.
• This procedure provides an arthroscopic alternative to certain forms of ulnar shortening surgery in appropriately selected cases.
• Preservation of the sigmoid notch and the stability of the distal radioulnar joint are important considerations.
• Excessive bone removal can compromise joint stability and should therefore be avoided.

Ganglion Cyst Excision

• Arthroscopic excision is an established minimally invasive treatment option for selected wrist ganglion cysts.
• Dorsal wrist ganglion excision is also commonly used as an introductory therapeutic procedure during wrist arthroscopy training.
• Arthroscopic treatment allows visualization of the cyst’s relationship to the joint and surrounding structures.

Wrist Arthritis and Carpometacarpal Arthroscopy

• Arthroscopy can also be performed in selected carpometacarpal joint disorders.
• A small-diameter arthroscope can be used to inspect the joint surface and surrounding structures.
• Arthroscopic assessment allows evaluation of:
  • Articular cartilage.
  • Joint surfaces.
  • Ligamentous structures.
  • Degenerative changes.
• Selected procedures for carpometacarpal arthritis may include arthroscopic debridement or resection-based procedures, depending on the joint involved and the severity of disease.

Advantages of Wrist Arthroscopy

• Minimally invasive access.
• High-resolution visualization of intra-articular structures.
• Ability to evaluate cartilage and ligament integrity directly.
• Assistance with accurate fracture reduction.
• Ability to diagnose and treat selected conditions during the same procedure.
• Potentially less disruption of surrounding soft tissues than open approaches.
• Ability to identify associated injuries that may not be apparent through external examination alone.

Limitations and Safety Considerations

• Wrist arthroscopy requires detailed knowledge of wrist anatomy and extensive technical training.
• The small working space leaves little margin for error.
• Important structures such as extensor tendons, sensory nerves, cartilage, and ligaments must be protected.
• Portal placement should be based on clearly identified anatomical landmarks.
• Sharp instruments should not be advanced deeply without appropriate control.
• Traction should be carefully regulated.
• Arthroscopy should be considered a specialized technique rather than a substitute for careful clinical assessment and appropriate imaging.

Future Development

• Wrist arthroscopy continues to evolve with advances in imaging, instrumentation, and minimally invasive techniques.
• Smaller and more flexible scopes may improve access to difficult anatomical regions.
• Improved shavers and other miniature instruments may expand the range of therapeutic procedures.
• Continued anatomical and clinical research may identify additional applications for arthroscopic treatment.
• The overall direction of development is toward increasingly precise, minimally invasive procedures that combine detailed visualization with tissue preservation.

Key Takeaways

• Wrist arthroscopy provides both diagnostic and therapeutic access to the small and complex structures of the wrist.
• Successful arthroscopy depends heavily on an accurate understanding of surface and portal anatomy.
• A systematic examination of the radiocarpal and midcarpal joints helps reduce the risk of missing pathology.
• Common applications include treatment of triangular fibrocartilage complex injuries, ligament injuries, selected distal radius and scaphoid fractures, scaphoid non-union, ganglion cysts, and ulnocarpal impaction.
• Arthroscopy can also assist with fracture reduction and assessment of associated ligamentous injuries.
• Modern high-definition optics and miniature instruments have significantly expanded the capabilities of wrist arthroscopy.
• Because of the close proximity of important tendons, nerves, ligaments, and cartilage, the procedure requires specialized training and careful attention to anatomy.