Michael J. Wheatley, MD Stephan J. Finical, MD

The surgical management of Kienbock's disease remains controversial. Acceptable outcomes have been reported with radial shortening [1], ulnar lengthening [21, limited carpal fusions [3, 41, and proximal row carpectomy [5, 61. Lunate excision alone is seldom utilized in the management of Kienbock's disease due to concerns about progressive carpal collapse following removal of this central carpal bone [3, 7, 81. We report a 32-year follow-up of a patient who underwent lunate excision only for treatment of Kienbock's disease with a successful outcome,

Patient Report

A 51-year-old right-hand-dominant man presented to the hand service for evaluation of a digital mucous cyst. His past history was significant for Kienbock's disease involving the right wrist. At age 19, he developed severe wrist pain located over the right lunate. Wrist active range of motion (AROM) at that time ranged from 45 degrees of extension to 30 degrees of flexion and was painful. Radiographs revealed avascular necrosis of the lunate. He underwent carpal exploration with the intraoperative findings of an avascular, collapsed lunate with chondromalacia in the scapholunate articulation. The remaining articular surfaces were normal. Lunate excision was performed and the dorsal capsule repaired. His wrist was placed in a cast for 2 weeks, after which he was started on AROM with an uneventful postoperative course. Pathology was consistent with Kienbock's disease.

The patient presented to the hand service again, 32 years following lunate excision, for treatment of an unrelated mucous cyst. He reported that since undergoing lunate excision, he had been able to work as a heavy laborer and auto mechanic without any wrist pain. He denied any limitations related to his wrist. Examination revealed painless wrist AROM from 15 degrees of extension to 40 degrees of flexion. Radiographs demonstrated mild radial carpal subchondral sclerosis with some carpal collapse. Negative ulnar variance was noted.

Discussion

Lunate excision alone is generally thought to be an inadequate treatment for Kienbock's disease [3, 7, a]. Most review articles present this treatment from a historical perspective only, noting that carpal collapse inevitably results following lunate excision. Although carpal collapse is well documented in biomechanical testing [71, it does not appear to be a certain outcome in the clinical setting following lunate excision and, even when present, does not inevitably lead to a poor out- come. In fact, clinical reports on lunate excision document excellent results in the majority of patients.

Several small series have been published documenting the results of lunate excision for Kienbock's disease [9-16]. The combined outcomes of the 82 reported patients reveal 50 (61%) excel- lent, 17 (21%) good, 9 (11%) fair, and 6 (7%) poor results as defined by the individual authors (Table). It was noted in the largest series that the length of follow-up did not seem to affect out- comes and no late deteriorations were noted [13). Carpal collapse occurred to some extent in most patients, but its presence did not seem to affect the functional outcome in most patients [15, 16]. Range of motion in excellent and good results generally equaled or exceeded preoperative motion, and many patients were noted to have returned to heavy labor.

These results compare favorably with those reported for other "more conventional" procedures for Kienbock's disease. The combined results of several series on radial shortening reveal 61% excellent, 24% good, 9% fair, and 60/o poor results, numbers remarkably similar to those re- ported for lunate excision alone [1]. A 4% non- union rate was noted for radial shortening [1). In Quenzer and Linscheid's [21 series of 64 patients undergoing ulnar lengthening, relief of pain was documented in 80% of patients (good or excellent results), but a 22% complication rate was reported and 44% of patients required subsequent plate removal. Watson and colleagues' [3, 4] series of 35 patients undergoing triscaphe fusion for Kienbock's disease demonstrated pain relief in 80% of patients at rest and 71% of patients during activity. Subsequent lunate excision was required in 18% of patients. Excellent results have also been demonstrated for proximal row carpectomy, although complication rates from 0% to 25% have been reported for this procedure when used to treat other disorders of the proximal carpal row [5, 6]. Scaphocapitate fusion and capitate shortening have also been advocated, with excellent results reported in the majority of the patients undergoing these procedures [17, 18). While such retrospective study comparisons are fraught with methodological errors, it has been clearly documented in the literature that many patients will do well with lunate excision alone.

This report does not suggest that lunate excision is an appropriate treatment for Kienbock's disease. Rather, it is apparent that some patients, such as the one reported here, will have long- term symptomatic relief with lunate excision. It remains to be determined which patients will do well with this procedure. Nonetheless, lunate excision is a simple operation with minimal morbidity, following which many patients seem to have a good long-term outcome. As such, it may not be appropriate to assign this operation to the category of "historical interest only."

Reported Series of Lunate Excision for Kienbock's Disease

Author Date No. of Wrists Results

Dornan 1949 16 7 excellent, 4 good, 4 fair, 1 poor Cave 1939 4 2 excellent, 2 good

Mouat and associa 1931 5 4 excellent, 1 fair

Marek 1957 4 2 excellent, 1 fair, 1 poor

Gillespie 1961 24 16 excellent, 5 good, 2 fair, 1 poor Taine 1965 2 2 excellent

Blanco 1985 13 10 excellent, 1 good, 2 poor

Kawai and colleagues 1988 14 7 excellent, 5 good, 2 fair

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