Courtesy: Gustavo Gomez Rodriguez, Buenos Aires, Argentina

 

Wrist Arthroscopy: Step by Step

Overview

• Wrist arthroscopy is a minimally invasive technique that allows direct visualization of the structures within the wrist through small portals.
• Compared with conventional open approaches, arthroscopy can reduce soft-tissue disruption and may facilitate recovery in appropriately selected patients.
• The technique can be used both for diagnosis and treatment, including assessment of cartilage, ligament injuries, fractures, and instability.
• A structured learning process is important because wrist arthroscopy requires familiarity with three-dimensional anatomy, portal placement, triangulation, and instrument handling.

Wrist Arthroscopic Portals

• The wrist contains six dorsal extensor compartments, and several commonly used arthroscopic portals are named according to their relationship to these compartments.
• The 3–4 portal is located between the third and fourth extensor compartments and is one of the principal portals used for radiocarpal arthroscopy.
• The 6R portal is positioned on the radial side of the extensor carpi ulnaris tendon and provides another important access point to the radiocarpal joint.
• Additional portals include the radial and ulnar midcarpal portals.
• Less commonly used portals may be selected according to the pathology being evaluated or treated.

Basic Arthroscopic Examination

• Portal placement is generally performed using a needle to identify the joint before making a small skin incision.
• A blunt instrument can then be used to safely enter the capsule before introducing the arthroscope.
• The radiocarpal joint provides visualization of important structures, including:
  • The lunate.
  • The proximal pole of the scaphoid.
  • The scaphoid and lunate facets of the distal radius.
• Examination can subsequently be extended to the midcarpal joint.
• With appropriate experience, a systematic examination of the radiocarpal and midcarpal joints can be performed efficiently.
• Direct visualization can provide information that may not be fully apparent on radiographs or fluoroscopy.

Developing Arthroscopic Skills

A progressive approach to training can help surgeons develop the necessary skills.

Early-Level Procedures

• Arthroscopic treatment of selected dorsal wrist ganglia.
• Arthroscopic assistance during relatively straightforward distal radius fractures.
• Arthroscopic assessment of suspected ligament injuries.

Intermediate-Level Procedures

• Arthroscopic assistance in more complex distal radius fractures.
• Treatment of selected triangular fibrocartilage complex injuries.
• Arthroscopic assistance during carpal fracture fixation.

Advanced Procedures

• Complex distal radius fractures.
• Complex ligament reconstruction.
• Selected distal radius malunions.
• Arthroscopic procedures involving basal thumb arthritis.

Cadaveric training and repeated practice can help develop triangulation, suturing, portal orientation, and instrument-control skills before undertaking complex clinical procedures.

Arthroscopic Treatment of Dorsal Wrist Ganglia

• Arthroscopic excision is an option for appropriately selected dorsal wrist ganglia.
• Potential advantages include smaller incisions and reduced soft-tissue disruption.
• The arthroscope and shaver can be introduced through appropriately selected portals.
• The origin or stalk of the ganglion is identified arthroscopically.
• Resection of the associated capsular tissue can be performed around the stalk.
• The procedure is continued until the ganglion’s communication with the joint has been adequately addressed.
• Careful identification of the surrounding extensor tendons is important during the procedure.

Arthroscopic Assistance in Distal Radius Fractures

• Arthroscopy can be particularly useful when a distal radius fracture involves the articular surface.
• Important goals of fracture treatment include restoration of:
  • Articular congruity.
  • Radial alignment.
  • Volar tilt.
  • Ulnar variance.
• Arthroscopy allows direct inspection of the articular surface and can help identify residual steps or gaps following fracture reduction.
• A probe may be used to manipulate or assess articular fragments.
• Temporary Kirschner wires can maintain reduction before definitive fixation.
• In selected impacted fractures, fragments can be elevated from beneath the articular surface through a cortical window before fixation.
• Arthroscopy can also reveal associated cartilage injury resulting from the original trauma.

Assessment of Scapholunate Ligament Injuries

• Wrist arthroscopy provides a direct method of assessing the integrity of the scapholunate ligament.
• Arthroscopic staging systems can help characterize the severity of scapholunate injury.
• In less severe injuries, a probe may enter the interval between the scaphoid and lunate without substantial instability.
• As instability progresses, the probe may pass more freely through the scapholunate interval.
• In advanced injuries, the arthroscope itself may be able to pass through the scapholunate interval between the radiocarpal and midcarpal compartments.
• Arthroscopy therefore provides useful information about the degree of ligament disruption and carpal instability.

Assessment of the Triangular Fibrocartilage Complex

• The triangular fibrocartilage complex is an important stabilizer of the distal radioulnar joint.
• Its peripheral attachments include superficial and deep components.
• The deep radioulnar ligament attachments at the ulnar fovea are particularly important for distal radioulnar joint stability.
• Arthroscopic examination can be used to assess the integrity of these attachments.
• The hook test can help evaluate the stability of the triangular fibrocartilage complex and its foveal attachment.
• The trampoline test assesses the tension and stability of the triangular fibrocartilage complex.
• These tests can help distinguish between stable and unstable peripheral triangular fibrocartilage complex injuries.

Arthroscopic-Assisted Triangular Fibrocartilage Complex Repair

• When the triangular fibrocartilage complex tissue is of adequate quality, repair may be considered for selected peripheral or foveal tears.
• Foveal repair aims to restore the attachment of the deep triangular fibrocartilage complex to the ulna.
• One described approach uses transosseous tunnels through the ulnar foveal region.
• Sutures can be passed through the triangular fibrocartilage complex and secured to restore the tissue to its anatomical attachment.
• A successful repair should improve the stability of the distal radioulnar joint.
• Arthroscopy allows direct assessment of the repair and can be used to reassess the triangular fibrocartilage complex after fixation.

When Reconstruction Is Required

• Primary repair is dependent on having adequate-quality tissue.
• Chronic injuries, severely damaged tissue, or irreparable triangular fibrocartilage complex tears may require reconstruction rather than simple repair.
• Tendon graft reconstruction is one possible approach in appropriately selected patients.
• The specific reconstruction technique should be selected according to the pattern of instability, tissue quality, associated deformity, and surgeon experience.

Arthroscopic Assistance in Scaphoid Fracture Fixation

• Scaphoid fractures are among the most common carpal fractures requiring surgical treatment.
• Arthroscopy can assist with reduction and provide direct visualization of the articular surfaces.
• It can also help confirm appropriate positioning of fixation hardware.
• During screw fixation, arthroscopy may allow visualization of the screw trajectory and help identify potential penetration of the cartilage or joint surface.
• This can complement fluoroscopic imaging during fracture fixation.

Complex Distal Radius Fractures

• Arthroscopy can be used as an adjunct during fixation of complex intra-articular distal radius fractures.
• The objective is to restore the articular surface while maintaining the overall alignment of the distal radius.
• A systematic reduction strategy may involve addressing fragments sequentially rather than attempting to reduce all fragments simultaneously.
• Arthroscopic visualization helps identify:
  • Articular steps.
  • Residual gaps.
  • Depressed fragments.
  • Cartilage injuries.
• A temporary Kirschner wire can be used as a joystick to manipulate difficult fragments.
• Once satisfactory reduction has been achieved, temporary fixation can be replaced or supplemented with definitive locking fixation.
• The final arthroscopic assessment can confirm restoration of articular congruity.

Scapholunate Instability and Ligament Reconstruction

• Chronic scapholunate instability can produce characteristic changes in carpal alignment.
• Imaging may demonstrate:
  • Scaphoid flexion.
  • An increased scapholunate angle.
  • Dorsal intercalated segment instability alignment.
  • Abnormal positioning of the scaphoid relative to the distal radius.
• Magnetic resonance imaging can demonstrate ligament injury and associated soft-tissue abnormalities.
• Computed tomography can provide detailed information regarding carpal bone position and rotation.
• Dynamic fluoroscopic examination may also be useful for assessing carpal instability.
• Arthroscopy helps determine whether the carpal alignment can still be corrected before proceeding with reconstruction.
• In selected cases, minimally invasive ligament reconstruction can use suture tape or tendon graft techniques.
• Three-dimensional guides are being explored to improve the accuracy of bone tunnel placement in reconstructive procedures.
• Arthroscopic assessment after reconstruction can help confirm restoration of the relationship between the scaphoid and lunate.

Arthroscopic Management of Distal Radius Malunion

• Even relatively small articular incongruities can be clinically significant in some patients.
• Arthroscopy can help visualize an articular step and guide correction during selected corrective osteotomy procedures.
• An arthroscopic-assisted approach may allow the surgeon to directly assess the articular surface while mobilizing the malunited fragment.
• The fragment can be elevated and repositioned to restore a more congruent joint surface.
• Temporary wires and fragment-specific fixation can be used to maintain the corrected position.
• Final fixation may be completed using an appropriate locking plate.
• Arthroscopy provides an opportunity to assess residual articular incongruity and cartilage damage.

Basal Thumb Arthritis

• Arthroscopy also has a role in selected cases of thumb carpometacarpal joint arthritis.
• It may be considered in appropriately selected patients with earlier-stage disease and suitable joint pathology.
• Commonly described arthroscopic portals allow triangulation of instruments while minimizing the risk to nearby sensory nerve branches.
• A systematic inspection of the joint can be performed by examining different regions of the articular surface.
• Synovial tissue can be debrided when indicated.
• Osteophytes and loose bodies may be removed arthroscopically.
• The condition of the cartilage on the trapezium and base of the first metacarpal can be assessed directly.
• In selected patients, arthroscopic trapeziectomy can be performed.
• A burr may be used to remove the trapezium progressively, while fluoroscopy can help assess the extent of bone removal.
• The extent of resection can be tailored to the clinical and surgical requirements.

Arthroscopy for Distal Radioulnar Joint Instability

• In patients with distal radioulnar joint instability, assessment of the triangular fibrocartilage complex is particularly important.
• Foveal detachment of the triangular fibrocartilage complex may contribute significantly to instability.
• If the tissue remains sufficiently healthy, an anatomical repair may restore stability.
• When the tissue is irreparable or of poor quality, ligament reconstruction using a graft may be necessary.
• Reconstruction techniques may recreate the stabilizing attachments around the distal radioulnar joint.
• Treatment should be individualized according to the cause and chronicity of instability, tissue quality, bony anatomy, and associated injuries.

Arthroscopy in Acute Scapholunate Injuries

• Arthroscopy can be valuable in acute scapholunate ligament injuries because it allows direct assessment of the reduction.
• Fluoroscopy is useful but may not always demonstrate subtle articular or ligamentous abnormalities.
• Arthroscopy can assist in confirming carpal alignment while temporary fixation is performed.
• Early treatment may allow repair or fixation of suitable ligament injuries before significant tissue contraction and secondary changes develop.
• Delayed or chronic injuries may require a reconstructive procedure rather than simple repair.

Key Takeaways

• Wrist arthroscopy is both a diagnostic and therapeutic technique.
• It provides direct visualization of the radiocarpal and midcarpal joints.
• Important applications include selected:
  • Dorsal wrist ganglia.
  • Distal radius fractures.
  • Scaphoid fractures.
  • Scapholunate ligament injuries.
  • Triangular fibrocartilage complex tears.
  • Distal radioulnar joint instability.
  • Distal radius malunions.
  • Basal thumb arthritis.
• Arthroscopy can complement fluoroscopy, computed tomography, magnetic resonance imaging, and conventional surgical techniques rather than necessarily replacing them.
• Successful wrist arthroscopy requires detailed knowledge of wrist anatomy, appropriate patient selection, careful portal placement, and substantial technical training.
• A gradual progression from basic procedures to complex reconstruction can help surgeons develop safe and effective arthroscopic skills.
• The principal advantages of arthroscopy are direct visualization, minimally invasive access, and the ability to diagnose and treat certain abnormalities during the same procedure.