Kienbock Disease Treatment & Management

The primary methods of nonoperative treatment are immobilization and anti-inflammatory medications. As noted previously, the natural history of Kienböck disease is not well determined. Therefore, treatment is primarily directed by the level of symptoms. Certainly, a very young patient, although 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.

A number of options are available for surgical management of Kienböck disease. The 2 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 6 categories, as follows:

• Lunate excision with or without replacement
• Joint-leveling procedures
• Intercarpal fusions
• Revascularization
• Salvage procedures
• Others

Lunate excision with or without replacement

• Simple lunate excision
• Excision with soft-tissue (fascial or palmaris longus tendon graft) replacement
• Silicone replacement arthroplasty

Joint-leveling procedures

Radial shortening and ulnar lengthening are the 2 options to level the joint. The goal is to produce a wrist with neutral ulnar variance, although 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 over ulnar lengthening because there is a lower complication rate with the volar-shortening procedure and because the 2 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.^{[6, 7]}

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 has revealed decreased success rates.

Several authors have reported scaphocapitate (SC) fusion. 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.

Finally, 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 the present time, 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.^{[8, 9, 10]} There are several sources for the pedicles, including the distal radius,^[11] pisiform,^[12] and pronator quadratus (Braun). Results with the use of pedicled distal radius grafts have shown improved grip strengths and progressive MRI evidence of revascularization over an 18- to 36-month period.^[13] Revascularization techniques may also be combined with other previously mentioned approaches. Revascularization is especially attractive for the young patient with ulnar-neutral or -positive variance in whom a radial shortening is not an option and in a 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.^[14] Wrist arthrodesis is the final option for patients with global wrist degeneration. Arthrodesis can be achieved successfully following a failed PRC.

Other procedures

Possible other procedures include the following:

• Cancellous bone grafting plus external fixation
• Arthroscopic debridement
• Wrist denervation
• Metaphyseal decompression
• Lunate core decompression^[15]

A reasonable approach to determining the surgical treatment of Kienböck disease based on stage 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 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

The natural history has not been well elucidated, primarily because few reported series focus exclusively on nonoperative treatment. Kristensen monitored 49 patients nonoperatively for an average of 20.5 years and found that 80% of the patients had no pain or had pain only with heavy labor.^[16] Most patients reported a gradual lessening of symptoms over time. This benign clinical picture was not mirrored by radiographic findings, as degenerative changes in the wrist were common and every lunate was deformed.

In a retrospective study comparing surgical treatment with nonsurgical treatment for patients with Kienböck disease, Delaere noted that surgical management did not appear to show superiority over nonsurgical treatment at 5 years of follow-up.^[17] Care should be taken in interpreting these results, however, because STT fusions were performed in the majority of those treated surgically. This procedure, as noted below, has not been shown to produce long-lasting good results. In addition, patients who had more advanced disease were more likely to undergo surgery.

Mikkelsen noted that 15 of 25 patients treated conservatively had daily problems with the wrist.^[18] He concluded that nonoperative treatment was not indicated for Kienböck disease. In the early stages of Kienböck disease, a short trial of casting may alleviate symptoms and obviate the need for surgery. These patients should be monitored closely so that surgery, if necessary, can be performed when radial shortening is still feasible.

Although initial success was seen with the use of a silicone spacer following lunate resection, this implant is no longer indicated. Alexander presented a 5-year follow-up of a group of 10 patients with silicone lunate replacements and noted 50% unsatisfactory results.^[19] Sixty percent of patients who had radiographs at final follow-up demonstrated evidence of silicone particulate synovitis. Lunate excision is not commonly recommended because of concerns of progression of carpal collapse. A fascial or palmaris anchovy replacement has had variable success in preventing subsequent collapse, although Carroll reported long-term (>10 y) success in a series of 10 patients treated with a fascial implant following lunate excision. He noted no evidence of carpal collapse, and all patients had unrestricted use of their hands.

Radial shortening remains a mainstay of treatment. It is a reliable, reproducible procedure with good results. Weiss and Quenzer have presented large series of radial shortenings.^{[20, 21, 22]} They have noted decreased pain in about 90% of patients, as well as improved motion and grip strength at 4-year follow-up. Weiss also demonstrated that good results can be obtained in patients with stage III disease who have evidence of lunate collapse. Despite good clinical outcomes, radiographic signs of continued collapse and degeneration are common. Although ulnar lengthening has demonstrated similar clinical outcomes, it is also associated with a higher complication rate. For this reason, radial shortening is the preferred joint-leveling method.

Watson reported on the use of STT (triscaphe) fusion for stage III disease and noted nearly 80% of his patients had good or excellent pain relief at 51-month follow-up.^[23] Caution should be used when evaluating these results, as nearly 40% of his patients required additional procedures to achieve this outcome. Compared to STT fusion, SC fusion has demonstrated similar pain relief rates but slightly decreased motion. Currently, no long-term results are available on the use of capitate shortening with or without capitohamate arthrodesis.^[1]

In a series of 51 patients who underwent vascular bundle implantation, 98% showed a reduction or resolution of pain at long-term follow-up. Again, these encouraging clinical results were not mirrored by radiographic improvement, as 20% had further degeneration and 10% had frank fragmentation. Results of the newer technique of distal radial vascular bone pedicle were noted previously.

The expected outcome following PRC is 75° in the flexion/extension arc and grip strength of 75% of the opposite side. Pain relief has been demonstrated in 80% of patients who underwent PRC for Kienböck disease. As noted, a PRC can be converted successfully to wrist arthrodesis.

Several other options for treatment have been reported. Ruby performed cancellous bone grafting supplemented by postoperative external fixation and found good pain relief in 80% of his patients.^[24] In patients with stage III disease and mechanical symptoms, arthroscopic debridement was found to decrease pain and increase motion. Finally, wrist denervation is a simple, safe option that can also be combined with other procedures to aid in postoperative pain reduction. In fact, denervation itself may provide much of the perceived pain reduction in cases where the dorsal capsule is incised to perform the index procedure.