CHAPTER SYNOPSIS:
Arthroscopy of the wrist allows extensive visualization of the radiocarpal and midcarpal articular surfaces with minimal disruption of the soft tissues or ligaments, thus allowing reduced pain and faster recovery. Wrist arthroscopy is a diagnostic or “staging” tool, but it also provides therapeutic options including joint debridement, synovectomy, and loose body removal.
IMPORTANT POINTS:
Wrist arthroscopy has an expanding role in the diagnosis and treatment of wrist arthritis.
Wrist arthroscopy provides more information on the condition of the articular surface than imaging modalities including magnetic resonance imaging (MRI).
Arthroscopy is a safe procedure, when performed correctly, with minimal complications.
CLINICAL/SURGICAL PEARLS:
Wrist arthroscopy can be used for evaluation of the articular surface and ligamentous structures of the wrist to help determine the optimal reconstructive or salvage procedure.
From a therapeutic standpoint, debridement of synovitis and unstable chondral lesions and removal of loose bodies can be done to temporize, but usually not cure, the painful wrist.
Early mobility will reduce postoperative wrist stiffness.
CLINICAL/SURGICAL PITFALLS:
When performing radial stylectomy:
Damage to the volar ligaments may lead to ulnar translocation of the carpus
Amount of resection should be checked using fluoroscopy with the traction removed to confirm there is no impingement
Failure to use blunt dissection and spread technique will lead to damage of surrounding structures and articular cartilage
INTRODUCTION
Arthroscopy of the smaller joints was slow to develop because of technical challenges and was not popularized until 1979 by Chen, who reported on 90 arthroscopic procedures of the wrist and finger joints in 43 patients using the Wantanabe 24 arthroscope. Since then, wrist arthroscopy has been refined, and its indications continue to evolve. As better equipment and new techniques are developed, it is likely that wrist arthroscopy will have an even greater role in the diagnosis and treatment of wrist arthritis.
This chapter will briefly review the current indications and advantages of using wrist arthroscopy as part of a comprehensive treatment strategy in dealing with the challenges of wrist arthritis.
INDICATIONS
Several indications for arthroscopy in wrist arthritis are outlined in Box 2-1 . One of the main advantages of arthroscopy of the wrist is that it allows for extensive visualization of the articular surfaces of the distal radius and carpal bones without disruption of the soft tissues or ligaments. This leads to faster recovery without compromising care of the patient. Mutimer and colleagues performed a comparison of magnetic resonance imaging (MRI) and wrist arthroscopy. Twenty patients with wrist pain were investigated over a 1-year period with both MRI and wrist arthroscopy. Only a fair correlation (K = 0.38) was seen between the two methods. The authors concluded that wrist arthroscopy provided more information on the condition of the articular surface and was a powerful tool in the evaluation and treatment of the painful degenerative wrist. In addition to an obvious diagnostic role, wrist arthroscopy offers potential therapeutic benefit as well. Arthroscopic debridement or limited excision of arthritic joint surfaces and synovitis and the extraction of loose bodies can be done with minimal or no collateral damage to the soft tissue envelope—an obvious advantage over analogous open techniques.
Evaluation and treatment of the radiocarpal joint
SLAC wrist
SNAC wrist
Preiser’s disease
Kienböck’s disease
Evaluation and treatment of the midcarpal joint
STT arthritis
Proximal pole hamate arthritis
Synovectomy for rheumatoid arthritis
Irrigation and debridement of the septic arthritis
Evaluation and treatment of cartilage lesions and removal of loose bodies associated with posttraumatic arthritis, inflammatory arthritis, and other causes of wrist arthritis
RADIOCARPAL JOINT
Scapholunate Disorders
The distal radius articulates with the scaphoid and lunate carpal bones. Normally, the scaphoid’s flexion torque is balanced by the triquetral’s extension torque via the “intercalating” lunate. When this balance is lost by disruption of the bones or connecting ligaments of the proximal row, the result is abnormal kinematics and redistribution of forces across the radiocarpal joint leading to progressive degenerative changes known as scapholunate advanced collapse (SLAC) , in the case of scapholunate interosseous ligament disruption, or scaphoid nonunion advanced collapse (SNAC) in the case of displaced scaphoid nonunion. As outlined in Table 2-1 , joint surface destruction proceeds in a predictable pattern ( Fig. 2-1 ). Similarly, a scaphoid fracture not only can disrupt carpal mechanics leading to a similar wrist arthrosis, but the “ragged” fracture edge also can damage the capitate surface. Treatment options include radial styloid excision, partial wrist fusion, proximal row carpectomy, and total wrist fusions, as outlined elsewhere in this text. This “decision tree” depends significantly on which joint surfaces are salvageable. Because patient counseling will be different for each of these surgical options, an accurate knowledge of the state of the articular surfaces is crucial. Imaging studies, although helpful, are inferior to the direct visualization allowed by modern arthroscopy techniques.
Stage | Definition |
---|---|
I | Arthritis localized to radial styloid |
II | Radioscaphoid arthritis ( Fig. 2-2 ) |
III | Capitolunate arthritis with migration of capitate into scapholunate junction ( Fig. 2-3 ) |
Other procedures that can be performed arthroscopically during “staging” include radial styloidectomy for short-term pain relief of the symptoms of impingement and to delay more aggressive procedures such as proximal row carpectomy and wrist arthrodesis. This procedure is usually reserved for the earlier stages of radiocarpal arthritis (e.g., SLAC Stages 1-2 and in low-demand patients with good wrist range of motion). It may also be used as an adjunct to other more aggressive procedures such as soft tissue or bony stabilization of the unstable scaphoid to prevent/delay progression of disease.
For SNAC wrist, arthroscopic debridement or excision of the distal pole of the scaphoid is indicated for chronic disease without advanced degenerative changes of the radiocarpal surface when obtaining scaphoid union is unlikely and as a temporizing procedure until a salvage procedure is needed. This procedure may be combined with an arthroscopic radial styloidectomy.
KIENBÖCK’S AND PREISER’S DISEASE
Avascular necrosis of the lunate was described by Robert Kienböck in 1910. It is more common in males and presents between the ages of 20 and 40 years. The clinical presentation includes wrist pain, tenderness localized over the region of the dorsal lunate, restricted range of motion, and grip weakness.
The etiology of Kienböck’s disease is likely multifactorial and may be the result of mechanical load or shear forces leading to vascular compromise. Other theories involve interruption of blood supply from repetitive trauma or ligamentous damage or venous congestion from local or systemic diseases such as sickle cell disease, gout, or corticosteroid use. The role of negative ulnar variance leading to abnormal forces across the lunate as suggested by Hulten is controversial. Other authors have suggested that anatomic risk factors for Kienböck’s disease include a smaller more radially inclined lunate compared to patients without Kienböck’s disease.
The diagnosis is usually made with imaging modalities such as plain x-rays or MRI. Classification traditionally has been done by radiographs using the Lichtman classification ( Table 2-2 ).
Stage I | Normal radiographic architecture and bone density except for the possibility of either a linear or compressive fracture. |
Stage II | Increased density (sclerotic changes) of the lunate without significant alteration of the size, shape, and anatomic relationships of the bone. |
Stage IIIA | Fragmentation, collapse, or both of the entire lunate associated with proximal migration of the capitate and without fixed scaphoid rotation. |
Stage IIIB | Stage IIIA changes combined with disruption of the carpal architecture, potential scapholunate dissociation, rotation of the scaphoid, and ulnar deviation of the triquetrum |
Stage IV | Stage III changes combined with generalized carpal degeneration |
Although this radiologic classification has high reliability and reproducibility, recently Ribak emphasized the discrepancy between radiographic and arthroscopic assessment of Kienböck’s disease. Bain and Begg have used arthroscopy to assess and classify ( Fig. 2-4 ) Kienböck’s disease based on the number of articular surfaces of the lunate and adjacent articulations, which are nonfunctional and arthritic. They stated that surgery is aimed at debridement of the joint, classifying the degree of arthritis, which will help direct the definitive procedure to be performed, therefore improving patient care. If the articular surfaces are intact, an arthroscopic synovectomy may still be a useful adjunct to a proximal radial shortening, if indicated. Although lunate fragmentation can be identified on imaging studies, the state of lunate facet may be less obvious. The decision to proceed with a proximal row carpectomy can be determined following arthroscopic confirmation of intact cartilage there. Involvement of the proximal lunate and lunate facet, with preservation of the midcarpal joint, however, may lead to the decision to perform a radioscapholunate fusion. More extensive involvement of the joint would require a wrist arthrodesis. Bain and colleagues concluded that arthroscopy provides a valuable assessment and subsequent classification of Kienböck’s disease. In their study, arthroscopy alone was performed for patients with Grade 0 or those with Grade III-IV disease who did not yet want a wrist arthrodesis.
Atraumatic avascular necrosis of the scaphoid or Preiser’s disease is an uncommon disorder that presents with swelling and pain to the dorsum of the wrist over the scaphoid. It is also characterized by decreased grip strength and range of motion. The etiology is unknown but thought to be multifactorial and similar to the etiology of Kienböck’s disease of the lunate. The natural history of this disease is degeneration of the radiocarpal joint again as a result of altered joint mechanics and increased abnormal contact between the scaphoid and radiocarpal joint. Unlike SLAC or SNAC wrists and even Kienböck’s, however, the pattern of progression is much less predictable. For Preiser’s, joint visualization as provided by arthroscopy may be even more helpful in determining salvage options.
MIDCARPAL JOINT
Scaphotrapeziotrapezoid Joint Arthritis
About 95% of degenerative arthritis involving the wrist occurs around the scaphoid. About 55% occurs secondary to SLAC, 26% involves the scaphotrapeziotrapezoid (STT) joint, and 14% occurs as a combination of both. STT arthritis occurs more commonly in postmenopausal women. Clinical examination will show swelling and fullness in the dorsal radial wrist in the region of the snuffbox and frequently a visible swelling about the volar radial wrist. The volar scaphoid and flexor carpi radialis (FCR) tunnel may demonstrate tenderness that is exacerbated by grip and radial deviation. Volar palpation of the scaphoid, as in performing a scaphoid shift test, will cause pain. A hyperpronated view of the wrist may show narrowing, subchondral cysts, or irregularity of the STT joint.
Other times, however, the radiographs are not diagnostic despite suggestive signs and symptoms. Here, arthroscopy can directly evaluate the STT joint. There are many articulations in addition to the STT joint that can cause radial-sided wrist pain, and inspection of these surfaces at the same time can support treatment focused on the STT joint as well. In addition to improved visualization of the joint, arthroscopy may be used for debridement either as a isolated treatment or as part of an open approach for joint reconstruction.
Proximal Pole of Hamate Arthritis
Proximal pole of hamate arthritis is a common cause of ulnar-sided wrist pain. It is usually seen in individuals who take part in sports requiring ulnar deviation of the wrist, such as golf. Proximal pole of hamate arthritis has been associated with patients with lunotriquetral instability/tears. Harley and colleagues found that 91% of their patients had some degree of lunotriquetral instability and thought that arthrosis of this joint may be part of the spectrum of ulnar-sided wrist degeneration. They proposed the acronym HALT (Hamate Arthrosis Lunotriquetral ligament Tear). Proximal pole of hamate arthritis is typically associated with Type 2 lunates because the hamate does not articulate with Type 1 lunates. Loading between the hamate and the medial facet of Type 2 lunates associated with repetitive forceful ulnar deviation seems to lead to arthrosis of this joint. Of patients with Type II lunates, 44% have this form of arthritis as opposed to 2% in Type 1 lunates ( Fig. 2-5 ).