Approach Considerations
The primary indication for operative treatment of Kienböck disease is persistent pain that does not respond to conservative treatment such as nonsteroidal anti-inflammatory drugs (NSAIDs) and immobilization. Most patients with Kienböck disease who have moderate-to-severe symptoms are candidates for operative intervention. The choice of operative technique is based on patient age, disease stage, and the presence or absence of ulnar variance.
The primary contraindication to consider in the operative treatment of Kienböck disease is ulnar-positive or ulnar-neutral variance because in patients with such variance, joint-leveling procedures (radial shortening and ulnar lengthening) cannot be performed.
Medical Therapy
The primary methods of nonoperative treatment are immobilization and adminstration of anti-inflammatory medications. Because the natural history of Kienböck disease is not well determined, treatment is primarily directed by the level of symptoms. Certainly, a very young patient, though an unusual presentation of Kienböck disease, should be given an adequate trial of immobilization in hopes of allowing revascularization of the lunate and preventing disease progression.
Surgical Therapy
A number of options are available for surgical management of Kienböck disease. The two most important pieces of information are the stage of the disease and the presence or absence of ulnar variance.
Directly comparing the results of different techniques is difficult because most studies have a fairly small number of patients and short follow-up. However, review of the literature reveals that many of the techniques result in very similar rates of good outcomes.
Operative treatment can be classified broadly into six categories, as follows:
-
Lunate excision with or without replacement
-
Joint-leveling procedures
-
Intercarpal fusions
-
Revascularization
-
Salvage procedures
-
Other procedures
Lunate excision with or without replacement
Available approaches include the following:
-
Simple lunate excision
-
Excision with soft-tissue (fascial or palmaris longus tendon graft) replacement
-
Replacement arthroplasty
Joint-leveling procedures
Radial shortening [26, 27] and ulnar lengthening are two options for leveling the joint. The goal is to produce a wrist with neutral ulnar variance, though correction should probably not exceed 4 mm, because nearly all strain reduction occurs in the first 2 mm of correction. Strains at the lunate can be reduced by 70% with an appropriate radial shortening or ulnar lengthening.
Currently, radial shortening with a volar distal radius locking plate is preferred to ulnar lengthening because there is a lower complication rate with the volar-shortening procedure and because the two procedures have shown similarly good outcomes. In patients with neutral or positive ulnar variance, shortening the radius is contraindicated. In this clinical situation, radial wedge osteotomies designed to decrease the radial inclination have been proposed. [28, 29, 30]
Intercarpal fusions
Various intercarpal fusions for the treatment of Kienböck disease have been reported. The goal is to reduce lunate strain and, in procedures that involve the scaphoid, to correct and maintain proper scaphoid position.
Of the limited intercarpal fusions reported, the greatest experience has been with scaphotrapeziotrapezoid (STT; triscaphe) fusion. STT arthrodesis does decrease lunate strain but merely by shifting it to the radioscaphoid joint. STT fusion in a cadaver model was found to provide strain reduction similar to that of joint-leveling procedures but with greater loss of motion. The use of STT fusion has waned in recent years because of complications and longer-term follow-up that revealed decreased success rates. [31]
Several authors have reported scaphocapitate (SC) fusion. [32] Biomechanically, this fusion has been shown to reduce strain at the radiolunate joint by about 10%. Some authors prefer this fusion because it requires only one fusion site and is technically easier to perform.
Scapholunocapitate (SLC) fusion with proximal lunate articular surface preservation has been described in the management of grade IIIA Kienböck disease. [33]
Capitohamate fusion has been reported in a study with a short follow-up. However, this fusion alone has been shown to be biomechanically ineffective in reducing lunate strain. If this fusion is combined with capitate shortening, significant reductions of load across the radiolunate and SC joints have been noted. This load reduction is offset by large force increases at the ulnotriquetral, triquetrohamate, and scaphotrapezial joints. This method also does not address the scaphoid rotation that occurs with stage IIIb disease.
At present, intercarpal fusions are more likely to be reserved for patients with neutral or positive ulnar variance in whom a joint-leveling procedure is contraindicated.
Revascularization
In the late 1970s, Hori presented his initial work on the use of a vascular pedicle directly implanted into the lunate. Nearly all of his patients showed improvement in their pain at later follow-up.
Currently, most revascularizations use vascularized bone pedicles. [34, 35, 36] There are several sources for the pedicles, including the distal radius, [37] pisiform, [38] and pronator quadratus (Braun). Results with the use of pedicled distal radius grafts have shown improved grip strengths and progressive evidence of revascularization on magnetic resonance imaging (MRI) over an 18- to 36-month period. [39]
A retrospective study by Windhofer et al reported good short-term and midterm results from the use of a lateral femoral trochlea osteochondral graft for lunate reconstruction in 27 patients with stage III Kienböck disease. [40]
A systematic review and single-arm meta-analysis by Park et al compared the long-term outcomes of vascularized bone graft (VBG) and nonoperative treatment in patients with Kienböck disease. [41] Greater improvements in radiographic stage and wrist pain were achieved with VBG than with nonoperative treatment, but meaningful differences in parameters were not observed.
Revascularization techniques may also be combined with other previously mentioned approaches. Revascularization may be especially attractive for the young patient with ulnar-neutral or ulnar-positive variance in whom a radial shortening is not an option and for the patient who wishes to avoid an intercarpal fusion and resultant loss of motion.
Salvage procedures
Salvage procedures are reserved for later stages of disease and for failures of other treatments. Proximal-row carpectomy (PRC) has been shown to provide relatively good results for Kienböck disease, as well as for other wrist problems. [42] Wrist arthrodesis is the final option for patients with global wrist degeneration. Arthrodesis can be achieved successfully after a failed PRC. SC arthrodesis has been suggested as an option for wrist salvage in cases of advanced Kienböck disease. [43]
Other procedures
Other possible procedures include the following:
-
Cancellous bone grafting plus external fixation
-
Arthroscopic debridement [44]
-
Wrist denervation
-
Metaphyseal decompression
Some studies have found partial capitate shortening to be effective for stage II and III Kienböck disease. [47, 48, 49]
Treatment based on disease stage
A reasonable approach to determining the surgical treatment of Kienböck disease on the basis of the stage of the disease is as follows:
-
Stage 0, I, II, or IIIa with ulnar-negative variance – Radial shortening, revascularization, denervation
-
Stage 0, I, II, or IIIa with ulnar-neutral or ulnar-positive variance – Revascularization, capitohamate (CH) fusion with capitate shortening, distal radius wedge osteotomy, denervation
-
Stage IIIb – SC fusion, radial shortening, denervation
-
Stage IV – PRC, total wrist arthrodesis, denervation
