- Email: [email protected]
Surgical treatment of scapholunate advanced collapse
Surgical Treatment of Scapholunate Advanced Collapse Joel D. Krakauer, MD, Allen T. Bishop, MD, William P. Cooney, MD, Rochester, MN This study reports the outcomes III scapholunate Scaphoid
advanced
excision
and intercarpal
sis in 23 cases and capitolunate formed
of six different
collapse
arthrodesis
was performed
arthrodesis
in 8 cases.
in 12 cases, radioscapholunate
cases, and primary of patients
arthrodesis
total wrist arthrodesis
group
motion-sparing
cases were converted
arthrodesis
diminished
reliably
a 54”flexion-extension radioscaphoid carpectomy
compared
procedures
with
in 31
wrist pain in patients
or proximal
best preserves
wrist
with
treatment
arthrodesis
Scaphoid
in 3
the majority
group.
excision
Six of 51
and four-corner
with stage III SLAC wristwhile
row carpectomy. mobility,
was per-
arthrodesis
rate was four cases for the capitolun-
for the four-corner
to total arthrodeses.
arthrode-
row carpectomy
surgical
arc. Stage II SLAC wrist can be successfully
arthrodesis,
cases: four-corner
Proximal
in 4 cases. Following two
for stage II and stage
an average of 50 months.
in 5 cases, radioscaphoid
in all groups had less wrist pain. The nonunion
ate arthrodesis
row
reconstructive
(SLAC) wrist in 55 cases followed
maintaining
treated with this procedure,
Of the three
a flexion-extension
procedures, arc of 71”.
proximal (1 Hand
Surg 1994; 19A:751-759.)
In 1984, Watson and Ballet’ described scapholunate advanced collapse (SLAC), the most common pattern of degenerative arthritis found in the wrist. In SLAC wrist, sequential arthritic degeneration occurs first at the level of the radial styloid and waist of the scaphoid. The changes then progress to affect the rest of the radioscaphoid joint, followed by the capitolunate joint. Progressive degenerative arthritis in these three areas may be designated SLAC wrist stages I, II, and III (Fig. 1). The radiolunate joint is commonly preserved even in advanced stage III disease where the radioscaphoid and capitolunate joint spaces are markedly narrowed. Most cases of SLAC wrist represent the late sequelae of scapholunate dissociation (Fig. 2). Chronic scaphoid nonunion can also lead to SLAC From the Department of Orthopedic Surgery, Mayo Clinic, and Mayo School of Medicine, Rochester, MN. Received for publication Dec. 10, 1992; accepted in revised form Dec. 7, 1993. No benefits in any form have been received or will be received from a commercial party related directly or indiretly to the subject of this aticle. Reprint requests: Allen T. Bishop, MD, Mayo Clinic, 200 First Street, SW. Rochester, MN 55905.
arthritis’ (Fig. 3), although this more correctly may be termed scaphoid nonunion advanced collapse (SNAC) wrist. Other causes of SLAC wrist include primary degenerative arthritis related to attenuation of the scapholunate ligament as well as calcium pyrophosphate dihydrate deposition disease (CPPD),3,4 a common condition in the elderly. Many patients with SLAC wrist have minimal symptoms5 The choice of surgical procedure for those with significant pain refractory to nonoperative measures is dictated, partly, by the extent of arthritis, whether or not the capitolunate joint is involved. Included in the list of possible procedures are scaphoid excision combined with limited intercarpal arthrodesis (with or without scaphoid prosthetic replacement), proximal row carpectomy, radiocarpal arthrodesis, total or silicone wrist arthroplasty, and complete arthrodesis. For many patients, motion-sparing procedures offer a functional advantage over wrist arthrodesis, but their durability over the long-term is a concern. Since Watson and Ballet’s original report in 1984’ promoting the success of silicone scaphoid replacement for SLAC wrist, reports of major problems with subluxation and dislocation6 and silicone synoThe journal
of Hand
Surgery
751
752
Krakauer
et al. / SLAC Wrist
Stage I
Stage II
Stage III
Figure 1. SLAC wrist stages I, II, and III. In stage I changes are limited to the radial styloid. In stage II the entire
scaphoid fossa is involved. In stage III the capitolunate joint is additionally narrowed and sclerotic. vitis’ have dramatically curtailed its use. Controversy surrounds the long-term success of proximal row carpectomy. 8-16 Similarly, the results of radiocarpal arthrodeses are mixed.“-*’ We report a 9year experience with surgical treatment of SLAC wrist by a variety of methods.
Materials and Methods The medical records of all patients who underwent reconstructive wrist surgery for arthritis between 1981 and 1990 were reviewed. Because the term SLAC wrist is relatively new, most diagnoses
were made retrospectively. Patients with an inflammatory arthropathy, such as rheumatoid arthritis or lupus, were excluded. Sixty cases were identified as stage II or stage III SLAC wrist that had been treated with either scaphoid excision and intercarpal arthrodesis, proximal row carpectomy, radiocarpal arthrodesis, or total wrist arthrodesis. Followup of l-9 years (mean, 50 months) was available for 55 cases in 54 patients. Data were obtained from surgical records, clinical evaluation, and x-ray films. In addition, a detailed questionnaire was sent to all patients to assess pain, function, and work status. Eight
patients
were
unable
to return
for longterm
Figure 2. (A) Posteroanterior and (B) lateral tomograms of a 44-year-old man’s right wrist. In addition to arthrosis of the radioscaphoid joint, sclerosis and joint space narrowing are seen at the capitolunate joint (arrows). Obvious scapholunate dissociation is present with the lunate assuming a dorsal intercalated segment instability stance. The radiolunate joint space is well preserved. All these findings are representative of stage III SLAC wrist. This patient was treated with scaphoid excision and 4-corner arthrodesis.
The Journal
Figure 3. Anteroposterior
wrist of a 56-year-old mechanic with stage 11SLAC wrist due to an old scaphoid nonunion. Arthrosis of the radioscaphoid joint is primarily limited to the distal fragment. followup examination but did send current x-ray films and measured their own wrist mobility using our range of motion charts.” Demographic data of the study group are listed in Table 1. There were 48 men and 6 women (1 man in group I had bilateral procedures), with a mean age of 50 years. In 38 cases surgery was performed on the dominant wrist and in 17 on the nondominant wrist. Thirty-one of the patients were manual laborers. The stage of disease was determined from preoperative x-ray films and findings at surgery. If the
Table 1. Demographics Group 1. (Scaphoid
excision. 4 corner arthrodesis) 2. (Scaphoid excision. capitolunate arthrodesis) Proximal row carpectomy (Radioscapholunate arthrodesis) (Radioscaphoid arthrodesis) (Total arthrodesis)
of Hand
Surgery
1994
753
stage differed between the x-ray film interpretation and the surgical record, the latter was taken as the correct stage. Invariably when there was a discrepancy, the x-ray film underestimated the degree of articular involvement, even in some cases where tomograms were available. In all wrists the radiolunate joint was well preserved. A history of wrist injury was present in 36 cases. History of scaphoid fracture was present in 8 cases. Seven had nonunions, and one had a malunion. Prior reconstructive wrist surgery had been performed in 11 cases, scapholunate ligament repair or reconstruction in 5 cases, scaphoid bone grafting for nonuion in 3 cases, arthrodesis for scapholunate dissociation in 2 cases, and scapholunate arthrodesis for scapholunate dissociation in one case. Four additional patients had undergone prior carpal tunnel release. The patients were divided into six groups based on surgical procedure. Group 1 consisted of 23 cases of scaphoid excision and arthrodesis between the capitate, lunate, triquetrum, and hamate (Ccorner arthrodesis). Group 2 included eight cases of scaphoid excision and intercarpal arthrodesis limited to the capitate and lunate. Group 3 included 12 cases of proximal row carpectomy. Group 4 represented five cases of radioscapholunate arthrodesis, and group 5 included three cases of radioscaphoid arthrodesis. Group 6 included four cases of primary total wrist arthrodesis. Primary silicone scaphoid replacement procedures or secondary procedures related to silicone failure were excluded from the study. The wrists in groups 3.4, and 5 were primarily stage II, while those in groups I, 2, and 6 were mostly stage III (Table 1). The methods of fixation used in group I were, staples in 3 cases, multiple Herbert screws in 1, and Kirschner wires (K-wires) in 19 cases. Among group
of the Six Treatment
Age Mean Years
Sex (M/F)
23 -
56
2211
I716
14
8
51
711
612
12
40
913
5
45
3 4
t1
/ Vol. 19A No. 5 September
Dotninunti Nottdomintrnt
Groups Stage II
Stage III
Meun Followup Period Months
I
22
41
2
I
7
70
814
9
11
39
5/O
411
I
4
68
46
2/l
211
1
3
27
50
410
113
4
I
86
Luhorers
754
Krakauer et al. / SLAC Wrist
2, staples were used in two cases and K-wires in six cases. Concurrent radial styloidectomy was performed for two cases in group I. A palmaris longus anchovy was used to fill the void left behind after scaphoid excision in one case. No material was inserted in the rest. In some group 1 and 2 cases the distal pole of the scaphoid was preserved to maintain ligamentous continuity, and in others the entire scaphoid was excised. In group 3 (proximal row carpectomy), radial styloidectomy was performed in three cases and K-wire fixation in two cases. Staples were used in one case of radioscapholunate arthrodesis; K-wires were used in the rest of the radiocarpal arthrodeses.
thritis represented in groups 1 and 2. Preoperative motion in group 6 was similar to groups 1 and 2, again reflecting similar stage of disease (Fig. 4). On average, postoperative flexion and extension were less than preoperative for all groups. Group 3 (proximal row carpectomy) achieved the best flexion-extension arc, averaging 71”, but preoperative motion was also relatively high. The flexion-extension and radial-ulnar deviation arcs were actually higher in group 1 than group 2 (group 1, 54” and 30”; group 2 50” and 28”, respectively), suggesting that inclusion of the hamate and triquetrum in the fusion mass does not deleteriously affect mobility. Grip Strength
Results Pain Relief
All patients initially presented with a chief complaint of wrist pain. Postoperatively, pain was rated as’none or rare, mild, moderate (pain with vigorous activity), or severe (pain limiting routine activities) (Table 2). Two patients each from groups 1, 3, and 4 with severe pain were converted to total arthrodesis and considered failures. Complete pain relief was ultimately obtained in only two of these six cases. The single patient in group 2 with severe pain had a newly discovered nonunion of the capitolunate arthrodesis site and underwent repeat bone grafting. Four of the proximal row carpectomies (group 3) showed x-ray film evidence of capitolunate joint space narrowing at final follow-up examination. One of these four cases was asymptomatic, one had moderate pain, and the other two had severe pain. One of the two cases with severe pain was converted to total arthrodesis and the pain resolved. The other patient was considering total arthrodesis. Range of Motion Preoperative flexion and extension were lower in groups 1 and 2 compared with groups 3, 4, and 5, undoubtedly related to the more severe stage of ar-
Table 2. Pain for the Six Treatment Group
1. 2. 3. 4. 5. 6.
(Scaphoid excision, 4-corner) (Scaphoid excision, capitolunate) (Proximal row carpectomy) (Radioscapholunate) (Radioscaphoid arthrodesis) (Total)
The grip strength results from a standard Jamar dynamometer represent the average of three determinations and are expressed as the percent strength of the opposite hand (Fig. 5). The operated hand was consistently weaker than the nonoperated hand both before and after surgery for all groups; however, there was consistent improvement in grip strength postoperatively. Work Status There were 31 manual laborers in the study. Seven of them had to modify their work duties postoperatively due to problems with their wrists. Four patients who once worked as laborers have not returned to work, two from group 2 and two from group 3. None of the nonmanual laborers have had to modify or restrict their employment. Nonunion
Requiring
Repeat Operation
Seven wrists required repeat bone grafting of a limited arthrodesis for painful nonunion: two from group 1, four from group 2, and one from group 5. In group 2, two wrists, required repeat bone grafting for scaphoid excision with intercarpal arthrodesis limited to the capitate and lunate. This compares to one wrist in group 1, when the triquetrum and ha-
Groups at Final Followup Examination*, None
or Rare
13 3 5 1 2 3
* Two patients with severe pain from groups 1, 3, and 4 were ultimately in group 2 with severe pain had a recently discovered nonunion.
Mild
3 3 2 0 1 1 converted
or Until Failure
Moderate
4 1 2 2 0 0 to total arthrodesis.
Severe
3 1 3 2 0 0 The single patient
The Journal
of Hand
i Vol. 19A No. 5 September
Surgery
1994
755
Extension
Flexion
Ulnar Deviation
Radial Deviation
30.7 l-l
”
Figure 4.
Group1 Group2 Gmup 3 Group4 Group 5
Group1 Group 2 Group3 Group4 Group5
Preoperative and postoperative range of motion for scaphoid excision and 4-corner arthrodesis (group I),
scaphoid excision and capitolunate arthrodesis (group 2), proximal row carpectomy sis (group 4). and radioscaphoid arthrodesis (group 5).
mate were included in the fusion mass. There was no correlation with the type of fixation used in the original procedure and subsequent nonunion. No cases of radioscapholunate arthrodesis or total wrist required repeat bone grafting. Conversion
(group 3). radioscapholunate
arthrode-
ma1 row carpectomy. Both patients with stage 111 SLAC wrist from groups 3 and 4 were among those who developed progressive arthrosis and went on to total arthrodesis. Pain has completely resolved in only two of the six who had secondary total arthrodeses.
to Total Arthrodesis
Six of the 5 I cases of motion-sparing procedures have since required total wrist arthrodesis. Two each were from groups 1, 3 and 5. Five were performed for painful progressive athrosis and one for continued pain with joint preservation after proxi-
78.5
Other Subsequent Complications
Operations
and
Three of the five patients from groups I and 7 in whom staples were used had them removed due to discomfort. There were two infections in group I
79.5
0
Preoperation
B
Postoperation 72.7
5
Group1
Group 2
Group 3
Group4
Group 5
Group 6
Preoperative and postoperative grip strength for patients with scaphoid excision and 4-corner arthrodesis (group I), scaphoid excision and capitolunate arthrodesis (group 2), proximal row carpectomy (group 3). radioscapholunate arthrodesis (group 4). radioscaphoid arthrodesis (group 5). and primary total arthrodesis (group 6).
Figure 5.
756
Krakauer et al. / SLAC Wrist
and one in group 4. One from group 1 was a deep infection requiring irrigation and debridement, and the other two were superficial infections treated with antibiotics. Discussion Etiology Scapholunate dissociation with dorsiflexion intercalated segment instability collapse of the scaphoid results in the loss of normal congruency between the elliptical articular surface of the scaphoid and the scaphoid fossa. ‘*2’ Forces between the malaligned articular surfaces can lead to radioscaphoid arthritis, initially at the radial styloid (stage I), and subsequently along the entire scaphoid fossa (stage II). Collapse of the carpus and attenuation of the restraining ligaments places excessive loads on the capitolunate joint, leading to capitolunate arthrosis (stage III). Using a biomechanical model, Viegasz2 confirmed that contact area and pressure are concentrated more under the scaphoid and lessened under the lunate with progressive perilunate instability, thus leading to SLAC wrist. Unlike the radioscaphoid and capitolunate articulations, the mating surfaces of the distal radius and lunate are spherical. The loads applied to the lunate remain perpendicular to its surface whether it is rotated into a palmar or dorsal stance. With the load remaining perpendicular to the surface, shear forces do not develop. The contour of the radioscaphoid joint comes to a point laterally, but is relatively spherical medially. This geometry helps explain why, in the presence of scaphoid nonunion, arthritis develops only around the distal fragment. The proximal fragment remains associated with the lunate through the interosseous ligament and rotates with the lunate in its relatively spherical bed. In advanced arthritis due to scaphoid nonunion, the scaphocapitate joint tends to be affected in addition to the capitolunate joint. In a retrospective analysis of x-ray films in 64 patients with symptomatic scaphoid nonunions, Vender2 found a high frequency of degenerative changes occurring in a predictable sequence as a function of time. For nonunions of 4 years’ duration, 48 patients had radioscaphoid changes, and for those of 9 years’ duration, 39 patients had midcarpal changes. Among our group, 37 patients gave a history of significant wrist trauma that predated their pain. Xray film evidence of an old scapholunate dissociation was confirmed at surgery in several additional patients who did not recall any wrist trauma. In some cases the etiology of the scapholunate dissociation was chronic attrition and attenuation of the
scapholunate ligament rather than a frank tear. These cases may represent a primary degenerative arthritis of the wrist rather than post-traumatic arthritis. Inflammatory arthropatheis can also predispose to scapholunate dissociation and may present with a SLAC type pattern of wear. Such patients were excluded from this study, however, to avoid an additional variable in the comparison of surgical procedures. An alternative etiology for the development of SLAC wrist has been advocated by Chen, Resnick, and co-workers.3.4 They identified an association with SLAC arthritis and CPPD. Among 168 patients4 with documented CPPD, 44 (26%) had x-ray film changes consistent with SLAC wrist. Selection bias precluded a determination of the true incidence of SLAC wrist in these patients, but there did seem to be a strong correlation. It should additionally be noted that the authors did not specify whether the patients in their study had a history of trauma. One 56-year-old man in our group had documented CPPD in multiple large joints. Interestingly, his wrist did not show the characteristic findings of CPPD. He was one of the two patients in group I who failed scaphoid excision and 4-corner arthrodesis and was converted to total arthrodesis. The failure, however, was attributed to inadequate reduction of the lunate from its extended stance, a critical step in the procedure as pointed out by Kirschenbaum et a1.‘3 Treatment Formal arthrodesis has long been advocated as the best salvage procedure for post-traumatic arthritis of the wrist.24325 While total arthrodesis reliably diminishes wrist pain, function is sacrificed. Among the four patients in our series with primary total arthrodeses (group 6), pain relief was achieved, but there were complaints regarding functional limitations that interfered with lifestyle. The question of what constitutes a functional range of wrist motion has been addressed by several authors. Palme? indicated 5” flexion and 30” extension was satisfactory, while Brumfeild”’ suggested 10”flexion and 35” extension. Ryu et a1.‘8 used a biaxial electrogoniometer to measure wrist motion in 40 volunteers performing 31 different activities. They found that 40 flexion, 40” extension, and 40” combined radial and ulnar deviation was compatible with adequate performance of most tasks of daily living. In our study, the flexion-extension arc was most effectively preserved with proximal row carpectomy (group 31, averaging 71”. Scaphoid excision and intercarpal arthrodesis was second best, with
The Journal
group I averaging 54” and group 2 averaging 50”. Inclusion of the ulnar side of the carpus in the fusion mass did not affect ultimate wrist motion and was associated with a much lower nonunion rate. Radiocarpal arthrodesis produced the lowest mobility in the flexion-extension plane despite relatively high preoperative motion. Inclusion of the lunate in the radiocarpal fusion mass did not make much difference in terms of ultimate range of motion but was associated with a higher failure rate than radioscaphoid arthrodesis alone. In their original description of SLAC wrist, Watson and Ballet’ reported a series of 13 silicone scaphoid replacements combined with limited intercarpal arthrodesis, 3 limited arthrodeses without scaphoid excision, and 4 silicone scaphoid replacements without arthrodesis. At 24-month follow-up examination, all but one had decreased pain, none had to change their jobs, and none developed radiolunate arthritis. Flexion averaged 43” and extension 40”. Complications were minimal. The authors indicated that when the silicone implant was left out of the procedure, the resting wrist moved to a position of radial deviation. This was not found in our study. Only one wrist among 31 assumed a radially deviated stance with ulnar translation of the carpus. Our preference has been to exclude the silicone scaphoid implants due to problems with dislocatiot$ and synovitis.’ Kirschenbaum et al.‘j reviewed 18 patients treated with scaphoid excision and capitolunate arthrodesis for radioscaphoid arthritis. In eight cases a silicone scaphoid was placed. They concluded that the scaphoid implant offered no advantage over scaphoid excision and limited arthrodesis alone. Six of their 18 capitolunate arthrodeses went on to pseudarthrosis compared to 4 of 8 in this series. Proximal row carpectomy (PRC) converts a mechanical link system into a simple hinge. According to Imbriglia, i’ the radius of curvature of the capitate head is roughly 60% of the lunate fossa in the anteroposterior and lateral planes. The motion that occurs following PRC is, therefore, a combination of translation and rotation. In 1964, Crabbe’ reported 24 cases of PRC performed for a variety of diagnoses including Kienbock’s disease, carpal dislocations, and scaphoid nonunions. Among the three failures in the series, two had scaphoid nonunions with arthritis. One went on to total arthrodesis and the other had persistent, severe pain. He concluded that “advanced degenerative changes are a contraindication, but mild to moderate changes do not appear to affect the results.” Inglis” reported 2-37-year follow-up on 12 patients undergoing PRC. again with a varity of preop-
of Hand
Surgery
/ Vol.
19A No. 5 September
1994
757
erative diagnoses. Their results were overall quite good with at least 45” flexion and extension in all patients, and “full motion” in five. Grip strength was “comparable to the other side,” and all the patients returned to work full time, including manual laborers. They concluded that “mild” degenerative arthritis did not preclude a good result and progressive collapse of the radiocapitate joint was not seen. Nevaiser14 felt that PRC had an undeservedly poor reputation and published a series of 24 patients in support of its use. All patients had post-traumatic disorders of the wrist, many of which would probably qualify as SLAC. Comparing the operated with the nonoperated wrists after 3 to 10 years of followup, flexion averaged 48-65% and extension averaged 65-70% of 24 patients. Grip strength was equal to the opposite side. Two wrists were subsequently converted to total arthrodesis for persistent pain, but neither had demonstrated collapse of the radiocapitate joint. Some cases did show deterioration of the radiocapitate joint, but this was not correlated with increased symptoms. In fact, at final follow-up examination , 22 were reported to be pain-free and mobile. A recent multicenter study16 reported results of 17 nonrheumatoid wrists 4 years following PRC. Three had severe pain postoperatively, and two were converted to total arthrodisis. Factors related to unsatisfactory outcome included employment as a laborer and more advanced arthritis. In our series, 3 of 12 PRCs resulted in severe pain. All three patients were laborers. Radiocapitate arthrosis was the source of pain in two. One of these two was converted to total arthrodesis 15 months following carpectomy and the pain resolved; the other was considering total arthrodesis. The source of severe pain in the third PRC patient was unclear. He underwent total arthrodesis despite a well-preserved capitolunate articulation and did not improve. The single case of stage III SLAC in group 3 was among those demonstrated progressive radiocapitate arthrosis. Clearly, there is a continuum from stage II to stage III SLAC with subtle articular cartilage changes making up the gray zone in between. The degree of acceptable articular wear is unclear, but the outcome is most likely to be favorable if the cartilage surfaces are intact. Like proximal row carpectomy, radiocarpal arthrodesis has received mixed reviews in the literature. Gordoni reported seven cases of radioscapholunate arthrodesis, four of which were for chronic scaphoid nonunion. All were reported to be painfree at followup examination with satisfactory motion, but no specifics were given. SchwartzZo reported five cases of radioscaphoid arthrodesis for
758
Krakauer et al. / SLAC Wrist
localized arthritis. Once again, specifics were lacking, but all seemed to have a good result. Minami et al.19 reported two radioscapholunate arthrodeses for scaphoid nonunion. One had a poor result due to progression of arthritis, and the other had a good result. The authors pointed out that one should anticipate rather marked limitation of wrist motion with this procedure since the scaphoid is made immobile, and thereby blocks motion at the midcarpal and radiocarpal joints. Bach et al.” recently reported 36 cases of radioscapholunte arthrodesis for radiocarpal arthritis. The etiology of the arthritis was scapholunate dissociation in 2 1 and scaphoid fracture in 5. Seven of the cases failed and were converted to total arthrodesis. Factors that predisposed to failure included midcarpal wear and a history of scaphoid nonuion. The authors emphasized the importance of carefully inspecting the midcarpal joint at the time of surgery to ensure the quality of articular cartilage. Among 18 patients examined at follow-up flexion averaged 17”, extension 3 1” ulnar deviation 13”, and radial deviation 8”. Grip strength averaged 75% of the contralateral hand. Two of our five patients with radioscapholunate arthrodeses developed progressive, painful degenerative arthritis postoperatively and were ultimately converted to total arthrodesis. One of the failures was in the single stage III case in group 4. The postoperative dimunition of flexion and extension was higher for the radiocarpal arthrodeses than the scahoid excisions and PRCs. While the radioscaphoid (group 5) had good pain relief and none failed, it is difficult to make definitive inferences regarding the potential advantages of this procedure since there were only three cases. Since this is a retrospective review of several different surgical treatments for SLAC wrist, it suffers from flaws inherent in such a study design. Some of the groups are small, thus precluding statistical appraisal of the results. The groups also vary with respect to the predominant stage of disease represented in each. Despite these obvious limitations, we feel that our data demonstrate that motion-sparing procedures provide satisfactory pain relief and motion in the majority of patients with stage II and stage III SLAC wrist and that scaphoid excision and intercarpal arthrodesis is the procedure of choice for stage III SLAC wrist. In addition, PRC gives the best motion but is associated with painful narrowing of the radiocapitate joint, and is best indicated in stage II SLAC where the articular surfaces of the capitate head and lunate fossa are intact. Finally, while in our study radioscapholunate fusion had the lowest success rate of all procedures and radiosca-
phoid fusion the highest, the difference in outcome between the two groups may be due to small sample size.
References Watson HK, Ballet FL. The SLAC wrist: scapholunate advanced collapse pattern of degenerative arthritis. J Hand Surg 1984;9A:358-65. 2. Vender MI, Watson HK, Wiener BD, Black DM. Degenerative change in symptomatic scaphoid nonI.
union. J Hand Surg 1987;12A:514-9. VP, Kang HS, Resnick D, Sartoris DJ, Haller J. Scapholunate advanced collapse: a common wrist abnormality in calcium pyrophosphate dihydrate deposition disease. Radiology 1990;2: 459-61. 4. Resnick D, Niwayama G. Carpal instability in rheumatoid arthritis and calcium pyrophosphate depostion disease: pathogenesis and roentgen appearance. Ann Rheum Dis 1977;36:31 l-8. 5. Fassler PR, Stern PJ, Kiefhaber TR. Asymptoamtic SLAC wrist: does it exist? J Hand Surg 1993;18A: 682-6. 6. Kleinert JM, Stern PJ, Lister GD, Kleinhaus RJ. Complications of scaphoid silicone arthroplaty. J Bone Joint Surg 1985:67A:422-7. Smith RJ, Atkinson RE, Jupiter JB. Silicone synovitis of the wrist. J Hand Surg 1985;10A:47-60. Crabbe WA. Excision of the proximal row of the carpus. J Bone Joint Surg 1964;46B:708-11. Ferlic DC, Clayton MC, Mills MF. Proximal row carpectomy: review of rheumatoid and nonrheumatoid wrists. J Hand Surg 1991;16A:420-4. 10. Harris WH, Jones WN, Aufranc OE. Problem cases from fracture gand rounds at the Massachusetts General Hospital. St Louis: Mosby, 1965:291. 11. Imbriglia JE, Broudy AS, Hagberg WC, McKernan D. Proximal row carpectomy: clinical evaluation. J Hand Surg 1990:15A:426-30. 12. Inglis AE, Jones EC. Proximal row carpectomy for diseases of the proximal row. J Bone Joint Surg 1977; 59A:460-3. 13. Jorgensen EC. Proximal row carpectomy: an end result of twenty-two cases. J Bone Joint Surg 1%9;51A: 1104-l. 14. Neviaser RJ. Proximal row carpectomy for post-traumatic disorders of the carpus. J Hand Surg 1983;8: 301-5. 15. Neviaser RJ. On resection of the proximal carpal row. Clin Orthop 1986;202: 12-5. 16. Culp RW, McGuigan FX, Turner MA, Lichtman DM, Osterman AL, McCarroll HR. Proximal row carpectomy: a multicenter study. J Hand Surg 1993;18A: 19-25. 17. Bach A, Almquist E, Newman D. Proximal row fusion as a solution for radiocarpal arthritis. J Hand Surg 1991;16A:424-31. 18. Gordon LH, King D. Partial wrist arthrodesis for old
3. Chen C, Chandnani
The Journal of Hand Surgery i Vol. 19A No. 5 September 19’14 759
19. 20. 21.
22.
23.
ununited fractures of the carpal navicular. Am J Surg 1961:102:460-4. Minami A, Ogino T, Minami M. Limited wrist fusions. J Hand Surg 1988;13A:660-7. Schwartz S. Localized fusion at the wrist joint. J Bone Joint Surgery 1967;49A:l591-6. Watson HK, Goodman ML, Johnson TR. Limited wrist arthrodesis. Part II: Intercarpal and radiocarpal combinations. J Hand Surg 1981;6:223-33. Viegas SF, Patterson RM, Peterson PD, et al. Evaluation of the biomechanical efficacy of limited intercarpal fusions for the treatment of scapho-lunate dissociation. J Hand Surg 1990:15A: 120-8. Kirschenbaum D, Schneider LH. Kirkpatrick WH, Adams DC, Cody RP. Scaphoid excision and capi-
24. 35. 26.
27.
28.
tolunate arthrodesis for radioscaphoid arthritis. J Hand Surg 1993:18A:780-5. Campbell CJ, Keokarn T. Total and subtotal arthrodesisofthe wrist. J Bone Joint Surg 1964:46A: 1520-33. Clayton ML, Ferlic DC. Arthrodesis of the arthritic wrist. Clin Orthop 1984:187:89-93. Palmer AK, Werner F, Murphy D, Glisson R. Functional wrist motion: a biomechanical study. J Hand Surg 1985:10A:39-46. Brumfield R. Nickel V. Nickel E. Joint motion in wrist flexion and extension. South Med J 1966:59: 909-10. Ryu J. Cooney WP, Askew LJ, An K. Chao EYS. Functional ranges of motion of the wrist joint. J Hand Surg 1991;16A:409-19.
advanced
excision
and intercarpal
sis in 23 cases and capitolunate formed
of six different
collapse
arthrodesis
was performed
arthrodesis
in 8 cases.
in 12 cases, radioscapholunate
cases, and primary of patients
arthrodesis
total wrist arthrodesis
group
motion-sparing
cases were converted
arthrodesis
diminished
reliably
a 54”flexion-extension radioscaphoid carpectomy
compared
procedures
with
in 31
wrist pain in patients
or proximal
best preserves
wrist
with
treatment
arthrodesis
Scaphoid
in 3
the majority
group.
excision
Six of 51
and four-corner
with stage III SLAC wristwhile
row carpectomy. mobility,
was per-
arthrodesis
rate was four cases for the capitolun-
for the four-corner
to total arthrodeses.
arthrode-
row carpectomy
surgical
arc. Stage II SLAC wrist can be successfully
arthrodesis,
cases: four-corner
Proximal
in 4 cases. Following two
for stage II and stage
an average of 50 months.
in 5 cases, radioscaphoid
in all groups had less wrist pain. The nonunion
ate arthrodesis
row
reconstructive
(SLAC) wrist in 55 cases followed
maintaining
treated with this procedure,
Of the three
a flexion-extension
procedures, arc of 71”.
proximal (1 Hand
Surg 1994; 19A:751-759.)
In 1984, Watson and Ballet’ described scapholunate advanced collapse (SLAC), the most common pattern of degenerative arthritis found in the wrist. In SLAC wrist, sequential arthritic degeneration occurs first at the level of the radial styloid and waist of the scaphoid. The changes then progress to affect the rest of the radioscaphoid joint, followed by the capitolunate joint. Progressive degenerative arthritis in these three areas may be designated SLAC wrist stages I, II, and III (Fig. 1). The radiolunate joint is commonly preserved even in advanced stage III disease where the radioscaphoid and capitolunate joint spaces are markedly narrowed. Most cases of SLAC wrist represent the late sequelae of scapholunate dissociation (Fig. 2). Chronic scaphoid nonunion can also lead to SLAC From the Department of Orthopedic Surgery, Mayo Clinic, and Mayo School of Medicine, Rochester, MN. Received for publication Dec. 10, 1992; accepted in revised form Dec. 7, 1993. No benefits in any form have been received or will be received from a commercial party related directly or indiretly to the subject of this aticle. Reprint requests: Allen T. Bishop, MD, Mayo Clinic, 200 First Street, SW. Rochester, MN 55905.
arthritis’ (Fig. 3), although this more correctly may be termed scaphoid nonunion advanced collapse (SNAC) wrist. Other causes of SLAC wrist include primary degenerative arthritis related to attenuation of the scapholunate ligament as well as calcium pyrophosphate dihydrate deposition disease (CPPD),3,4 a common condition in the elderly. Many patients with SLAC wrist have minimal symptoms5 The choice of surgical procedure for those with significant pain refractory to nonoperative measures is dictated, partly, by the extent of arthritis, whether or not the capitolunate joint is involved. Included in the list of possible procedures are scaphoid excision combined with limited intercarpal arthrodesis (with or without scaphoid prosthetic replacement), proximal row carpectomy, radiocarpal arthrodesis, total or silicone wrist arthroplasty, and complete arthrodesis. For many patients, motion-sparing procedures offer a functional advantage over wrist arthrodesis, but their durability over the long-term is a concern. Since Watson and Ballet’s original report in 1984’ promoting the success of silicone scaphoid replacement for SLAC wrist, reports of major problems with subluxation and dislocation6 and silicone synoThe journal
of Hand
Surgery
751
752
Krakauer
et al. / SLAC Wrist
Stage I
Stage II
Stage III
Figure 1. SLAC wrist stages I, II, and III. In stage I changes are limited to the radial styloid. In stage II the entire
scaphoid fossa is involved. In stage III the capitolunate joint is additionally narrowed and sclerotic. vitis’ have dramatically curtailed its use. Controversy surrounds the long-term success of proximal row carpectomy. 8-16 Similarly, the results of radiocarpal arthrodeses are mixed.“-*’ We report a 9year experience with surgical treatment of SLAC wrist by a variety of methods.
Materials and Methods The medical records of all patients who underwent reconstructive wrist surgery for arthritis between 1981 and 1990 were reviewed. Because the term SLAC wrist is relatively new, most diagnoses
were made retrospectively. Patients with an inflammatory arthropathy, such as rheumatoid arthritis or lupus, were excluded. Sixty cases were identified as stage II or stage III SLAC wrist that had been treated with either scaphoid excision and intercarpal arthrodesis, proximal row carpectomy, radiocarpal arthrodesis, or total wrist arthrodesis. Followup of l-9 years (mean, 50 months) was available for 55 cases in 54 patients. Data were obtained from surgical records, clinical evaluation, and x-ray films. In addition, a detailed questionnaire was sent to all patients to assess pain, function, and work status. Eight
patients
were
unable
to return
for longterm
Figure 2. (A) Posteroanterior and (B) lateral tomograms of a 44-year-old man’s right wrist. In addition to arthrosis of the radioscaphoid joint, sclerosis and joint space narrowing are seen at the capitolunate joint (arrows). Obvious scapholunate dissociation is present with the lunate assuming a dorsal intercalated segment instability stance. The radiolunate joint space is well preserved. All these findings are representative of stage III SLAC wrist. This patient was treated with scaphoid excision and 4-corner arthrodesis.
The Journal
Figure 3. Anteroposterior
wrist of a 56-year-old mechanic with stage 11SLAC wrist due to an old scaphoid nonunion. Arthrosis of the radioscaphoid joint is primarily limited to the distal fragment. followup examination but did send current x-ray films and measured their own wrist mobility using our range of motion charts.” Demographic data of the study group are listed in Table 1. There were 48 men and 6 women (1 man in group I had bilateral procedures), with a mean age of 50 years. In 38 cases surgery was performed on the dominant wrist and in 17 on the nondominant wrist. Thirty-one of the patients were manual laborers. The stage of disease was determined from preoperative x-ray films and findings at surgery. If the
Table 1. Demographics Group 1. (Scaphoid
excision. 4 corner arthrodesis) 2. (Scaphoid excision. capitolunate arthrodesis) Proximal row carpectomy (Radioscapholunate arthrodesis) (Radioscaphoid arthrodesis) (Total arthrodesis)
of Hand
Surgery
1994
753
stage differed between the x-ray film interpretation and the surgical record, the latter was taken as the correct stage. Invariably when there was a discrepancy, the x-ray film underestimated the degree of articular involvement, even in some cases where tomograms were available. In all wrists the radiolunate joint was well preserved. A history of wrist injury was present in 36 cases. History of scaphoid fracture was present in 8 cases. Seven had nonunions, and one had a malunion. Prior reconstructive wrist surgery had been performed in 11 cases, scapholunate ligament repair or reconstruction in 5 cases, scaphoid bone grafting for nonuion in 3 cases, arthrodesis for scapholunate dissociation in 2 cases, and scapholunate arthrodesis for scapholunate dissociation in one case. Four additional patients had undergone prior carpal tunnel release. The patients were divided into six groups based on surgical procedure. Group 1 consisted of 23 cases of scaphoid excision and arthrodesis between the capitate, lunate, triquetrum, and hamate (Ccorner arthrodesis). Group 2 included eight cases of scaphoid excision and intercarpal arthrodesis limited to the capitate and lunate. Group 3 included 12 cases of proximal row carpectomy. Group 4 represented five cases of radioscapholunate arthrodesis, and group 5 included three cases of radioscaphoid arthrodesis. Group 6 included four cases of primary total wrist arthrodesis. Primary silicone scaphoid replacement procedures or secondary procedures related to silicone failure were excluded from the study. The wrists in groups 3.4, and 5 were primarily stage II, while those in groups I, 2, and 6 were mostly stage III (Table 1). The methods of fixation used in group I were, staples in 3 cases, multiple Herbert screws in 1, and Kirschner wires (K-wires) in 19 cases. Among group
of the Six Treatment
Age Mean Years
Sex (M/F)
23 -
56
2211
I716
14
8
51
711
612
12
40
913
5
45
3 4
t1
/ Vol. 19A No. 5 September
Dotninunti Nottdomintrnt
Groups Stage II
Stage III
Meun Followup Period Months
I
22
41
2
I
7
70
814
9
11
39
5/O
411
I
4
68
46
2/l
211
1
3
27
50
410
113
4
I
86
Luhorers
754
Krakauer et al. / SLAC Wrist
2, staples were used in two cases and K-wires in six cases. Concurrent radial styloidectomy was performed for two cases in group I. A palmaris longus anchovy was used to fill the void left behind after scaphoid excision in one case. No material was inserted in the rest. In some group 1 and 2 cases the distal pole of the scaphoid was preserved to maintain ligamentous continuity, and in others the entire scaphoid was excised. In group 3 (proximal row carpectomy), radial styloidectomy was performed in three cases and K-wire fixation in two cases. Staples were used in one case of radioscapholunate arthrodesis; K-wires were used in the rest of the radiocarpal arthrodeses.
thritis represented in groups 1 and 2. Preoperative motion in group 6 was similar to groups 1 and 2, again reflecting similar stage of disease (Fig. 4). On average, postoperative flexion and extension were less than preoperative for all groups. Group 3 (proximal row carpectomy) achieved the best flexion-extension arc, averaging 71”, but preoperative motion was also relatively high. The flexion-extension and radial-ulnar deviation arcs were actually higher in group 1 than group 2 (group 1, 54” and 30”; group 2 50” and 28”, respectively), suggesting that inclusion of the hamate and triquetrum in the fusion mass does not deleteriously affect mobility. Grip Strength
Results Pain Relief
All patients initially presented with a chief complaint of wrist pain. Postoperatively, pain was rated as’none or rare, mild, moderate (pain with vigorous activity), or severe (pain limiting routine activities) (Table 2). Two patients each from groups 1, 3, and 4 with severe pain were converted to total arthrodesis and considered failures. Complete pain relief was ultimately obtained in only two of these six cases. The single patient in group 2 with severe pain had a newly discovered nonunion of the capitolunate arthrodesis site and underwent repeat bone grafting. Four of the proximal row carpectomies (group 3) showed x-ray film evidence of capitolunate joint space narrowing at final follow-up examination. One of these four cases was asymptomatic, one had moderate pain, and the other two had severe pain. One of the two cases with severe pain was converted to total arthrodesis and the pain resolved. The other patient was considering total arthrodesis. Range of Motion Preoperative flexion and extension were lower in groups 1 and 2 compared with groups 3, 4, and 5, undoubtedly related to the more severe stage of ar-
Table 2. Pain for the Six Treatment Group
1. 2. 3. 4. 5. 6.
(Scaphoid excision, 4-corner) (Scaphoid excision, capitolunate) (Proximal row carpectomy) (Radioscapholunate) (Radioscaphoid arthrodesis) (Total)
The grip strength results from a standard Jamar dynamometer represent the average of three determinations and are expressed as the percent strength of the opposite hand (Fig. 5). The operated hand was consistently weaker than the nonoperated hand both before and after surgery for all groups; however, there was consistent improvement in grip strength postoperatively. Work Status There were 31 manual laborers in the study. Seven of them had to modify their work duties postoperatively due to problems with their wrists. Four patients who once worked as laborers have not returned to work, two from group 2 and two from group 3. None of the nonmanual laborers have had to modify or restrict their employment. Nonunion
Requiring
Repeat Operation
Seven wrists required repeat bone grafting of a limited arthrodesis for painful nonunion: two from group 1, four from group 2, and one from group 5. In group 2, two wrists, required repeat bone grafting for scaphoid excision with intercarpal arthrodesis limited to the capitate and lunate. This compares to one wrist in group 1, when the triquetrum and ha-
Groups at Final Followup Examination*, None
or Rare
13 3 5 1 2 3
* Two patients with severe pain from groups 1, 3, and 4 were ultimately in group 2 with severe pain had a recently discovered nonunion.
Mild
3 3 2 0 1 1 converted
or Until Failure
Moderate
4 1 2 2 0 0 to total arthrodesis.
Severe
3 1 3 2 0 0 The single patient
The Journal
of Hand
i Vol. 19A No. 5 September
Surgery
1994
755
Extension
Flexion
Ulnar Deviation
Radial Deviation
30.7 l-l
”
Figure 4.
Group1 Group2 Gmup 3 Group4 Group 5
Group1 Group 2 Group3 Group4 Group5
Preoperative and postoperative range of motion for scaphoid excision and 4-corner arthrodesis (group I),
scaphoid excision and capitolunate arthrodesis (group 2), proximal row carpectomy sis (group 4). and radioscaphoid arthrodesis (group 5).
mate were included in the fusion mass. There was no correlation with the type of fixation used in the original procedure and subsequent nonunion. No cases of radioscapholunate arthrodesis or total wrist required repeat bone grafting. Conversion
(group 3). radioscapholunate
arthrode-
ma1 row carpectomy. Both patients with stage 111 SLAC wrist from groups 3 and 4 were among those who developed progressive arthrosis and went on to total arthrodesis. Pain has completely resolved in only two of the six who had secondary total arthrodeses.
to Total Arthrodesis
Six of the 5 I cases of motion-sparing procedures have since required total wrist arthrodesis. Two each were from groups 1, 3 and 5. Five were performed for painful progressive athrosis and one for continued pain with joint preservation after proxi-
78.5
Other Subsequent Complications
Operations
and
Three of the five patients from groups I and 7 in whom staples were used had them removed due to discomfort. There were two infections in group I
79.5
0
Preoperation
B
Postoperation 72.7
5
Group1
Group 2
Group 3
Group4
Group 5
Group 6
Preoperative and postoperative grip strength for patients with scaphoid excision and 4-corner arthrodesis (group I), scaphoid excision and capitolunate arthrodesis (group 2), proximal row carpectomy (group 3). radioscapholunate arthrodesis (group 4). radioscaphoid arthrodesis (group 5). and primary total arthrodesis (group 6).
Figure 5.
756
Krakauer et al. / SLAC Wrist
and one in group 4. One from group 1 was a deep infection requiring irrigation and debridement, and the other two were superficial infections treated with antibiotics. Discussion Etiology Scapholunate dissociation with dorsiflexion intercalated segment instability collapse of the scaphoid results in the loss of normal congruency between the elliptical articular surface of the scaphoid and the scaphoid fossa. ‘*2’ Forces between the malaligned articular surfaces can lead to radioscaphoid arthritis, initially at the radial styloid (stage I), and subsequently along the entire scaphoid fossa (stage II). Collapse of the carpus and attenuation of the restraining ligaments places excessive loads on the capitolunate joint, leading to capitolunate arthrosis (stage III). Using a biomechanical model, Viegasz2 confirmed that contact area and pressure are concentrated more under the scaphoid and lessened under the lunate with progressive perilunate instability, thus leading to SLAC wrist. Unlike the radioscaphoid and capitolunate articulations, the mating surfaces of the distal radius and lunate are spherical. The loads applied to the lunate remain perpendicular to its surface whether it is rotated into a palmar or dorsal stance. With the load remaining perpendicular to the surface, shear forces do not develop. The contour of the radioscaphoid joint comes to a point laterally, but is relatively spherical medially. This geometry helps explain why, in the presence of scaphoid nonunion, arthritis develops only around the distal fragment. The proximal fragment remains associated with the lunate through the interosseous ligament and rotates with the lunate in its relatively spherical bed. In advanced arthritis due to scaphoid nonunion, the scaphocapitate joint tends to be affected in addition to the capitolunate joint. In a retrospective analysis of x-ray films in 64 patients with symptomatic scaphoid nonunions, Vender2 found a high frequency of degenerative changes occurring in a predictable sequence as a function of time. For nonunions of 4 years’ duration, 48 patients had radioscaphoid changes, and for those of 9 years’ duration, 39 patients had midcarpal changes. Among our group, 37 patients gave a history of significant wrist trauma that predated their pain. Xray film evidence of an old scapholunate dissociation was confirmed at surgery in several additional patients who did not recall any wrist trauma. In some cases the etiology of the scapholunate dissociation was chronic attrition and attenuation of the
scapholunate ligament rather than a frank tear. These cases may represent a primary degenerative arthritis of the wrist rather than post-traumatic arthritis. Inflammatory arthropatheis can also predispose to scapholunate dissociation and may present with a SLAC type pattern of wear. Such patients were excluded from this study, however, to avoid an additional variable in the comparison of surgical procedures. An alternative etiology for the development of SLAC wrist has been advocated by Chen, Resnick, and co-workers.3.4 They identified an association with SLAC arthritis and CPPD. Among 168 patients4 with documented CPPD, 44 (26%) had x-ray film changes consistent with SLAC wrist. Selection bias precluded a determination of the true incidence of SLAC wrist in these patients, but there did seem to be a strong correlation. It should additionally be noted that the authors did not specify whether the patients in their study had a history of trauma. One 56-year-old man in our group had documented CPPD in multiple large joints. Interestingly, his wrist did not show the characteristic findings of CPPD. He was one of the two patients in group I who failed scaphoid excision and 4-corner arthrodesis and was converted to total arthrodesis. The failure, however, was attributed to inadequate reduction of the lunate from its extended stance, a critical step in the procedure as pointed out by Kirschenbaum et a1.‘3 Treatment Formal arthrodesis has long been advocated as the best salvage procedure for post-traumatic arthritis of the wrist.24325 While total arthrodesis reliably diminishes wrist pain, function is sacrificed. Among the four patients in our series with primary total arthrodeses (group 6), pain relief was achieved, but there were complaints regarding functional limitations that interfered with lifestyle. The question of what constitutes a functional range of wrist motion has been addressed by several authors. Palme? indicated 5” flexion and 30” extension was satisfactory, while Brumfeild”’ suggested 10”flexion and 35” extension. Ryu et a1.‘8 used a biaxial electrogoniometer to measure wrist motion in 40 volunteers performing 31 different activities. They found that 40 flexion, 40” extension, and 40” combined radial and ulnar deviation was compatible with adequate performance of most tasks of daily living. In our study, the flexion-extension arc was most effectively preserved with proximal row carpectomy (group 31, averaging 71”. Scaphoid excision and intercarpal arthrodesis was second best, with
The Journal
group I averaging 54” and group 2 averaging 50”. Inclusion of the ulnar side of the carpus in the fusion mass did not affect ultimate wrist motion and was associated with a much lower nonunion rate. Radiocarpal arthrodesis produced the lowest mobility in the flexion-extension plane despite relatively high preoperative motion. Inclusion of the lunate in the radiocarpal fusion mass did not make much difference in terms of ultimate range of motion but was associated with a higher failure rate than radioscaphoid arthrodesis alone. In their original description of SLAC wrist, Watson and Ballet’ reported a series of 13 silicone scaphoid replacements combined with limited intercarpal arthrodesis, 3 limited arthrodeses without scaphoid excision, and 4 silicone scaphoid replacements without arthrodesis. At 24-month follow-up examination, all but one had decreased pain, none had to change their jobs, and none developed radiolunate arthritis. Flexion averaged 43” and extension 40”. Complications were minimal. The authors indicated that when the silicone implant was left out of the procedure, the resting wrist moved to a position of radial deviation. This was not found in our study. Only one wrist among 31 assumed a radially deviated stance with ulnar translation of the carpus. Our preference has been to exclude the silicone scaphoid implants due to problems with dislocatiot$ and synovitis.’ Kirschenbaum et al.‘j reviewed 18 patients treated with scaphoid excision and capitolunate arthrodesis for radioscaphoid arthritis. In eight cases a silicone scaphoid was placed. They concluded that the scaphoid implant offered no advantage over scaphoid excision and limited arthrodesis alone. Six of their 18 capitolunate arthrodeses went on to pseudarthrosis compared to 4 of 8 in this series. Proximal row carpectomy (PRC) converts a mechanical link system into a simple hinge. According to Imbriglia, i’ the radius of curvature of the capitate head is roughly 60% of the lunate fossa in the anteroposterior and lateral planes. The motion that occurs following PRC is, therefore, a combination of translation and rotation. In 1964, Crabbe’ reported 24 cases of PRC performed for a variety of diagnoses including Kienbock’s disease, carpal dislocations, and scaphoid nonunions. Among the three failures in the series, two had scaphoid nonunions with arthritis. One went on to total arthrodesis and the other had persistent, severe pain. He concluded that “advanced degenerative changes are a contraindication, but mild to moderate changes do not appear to affect the results.” Inglis” reported 2-37-year follow-up on 12 patients undergoing PRC. again with a varity of preop-
of Hand
Surgery
/ Vol.
19A No. 5 September
1994
757
erative diagnoses. Their results were overall quite good with at least 45” flexion and extension in all patients, and “full motion” in five. Grip strength was “comparable to the other side,” and all the patients returned to work full time, including manual laborers. They concluded that “mild” degenerative arthritis did not preclude a good result and progressive collapse of the radiocapitate joint was not seen. Nevaiser14 felt that PRC had an undeservedly poor reputation and published a series of 24 patients in support of its use. All patients had post-traumatic disorders of the wrist, many of which would probably qualify as SLAC. Comparing the operated with the nonoperated wrists after 3 to 10 years of followup, flexion averaged 48-65% and extension averaged 65-70% of 24 patients. Grip strength was equal to the opposite side. Two wrists were subsequently converted to total arthrodesis for persistent pain, but neither had demonstrated collapse of the radiocapitate joint. Some cases did show deterioration of the radiocapitate joint, but this was not correlated with increased symptoms. In fact, at final follow-up examination , 22 were reported to be pain-free and mobile. A recent multicenter study16 reported results of 17 nonrheumatoid wrists 4 years following PRC. Three had severe pain postoperatively, and two were converted to total arthrodisis. Factors related to unsatisfactory outcome included employment as a laborer and more advanced arthritis. In our series, 3 of 12 PRCs resulted in severe pain. All three patients were laborers. Radiocapitate arthrosis was the source of pain in two. One of these two was converted to total arthrodesis 15 months following carpectomy and the pain resolved; the other was considering total arthrodesis. The source of severe pain in the third PRC patient was unclear. He underwent total arthrodesis despite a well-preserved capitolunate articulation and did not improve. The single case of stage III SLAC in group 3 was among those demonstrated progressive radiocapitate arthrosis. Clearly, there is a continuum from stage II to stage III SLAC with subtle articular cartilage changes making up the gray zone in between. The degree of acceptable articular wear is unclear, but the outcome is most likely to be favorable if the cartilage surfaces are intact. Like proximal row carpectomy, radiocarpal arthrodesis has received mixed reviews in the literature. Gordoni reported seven cases of radioscapholunate arthrodesis, four of which were for chronic scaphoid nonunion. All were reported to be painfree at followup examination with satisfactory motion, but no specifics were given. SchwartzZo reported five cases of radioscaphoid arthrodesis for
758
Krakauer et al. / SLAC Wrist
localized arthritis. Once again, specifics were lacking, but all seemed to have a good result. Minami et al.19 reported two radioscapholunate arthrodeses for scaphoid nonunion. One had a poor result due to progression of arthritis, and the other had a good result. The authors pointed out that one should anticipate rather marked limitation of wrist motion with this procedure since the scaphoid is made immobile, and thereby blocks motion at the midcarpal and radiocarpal joints. Bach et al.” recently reported 36 cases of radioscapholunte arthrodesis for radiocarpal arthritis. The etiology of the arthritis was scapholunate dissociation in 2 1 and scaphoid fracture in 5. Seven of the cases failed and were converted to total arthrodesis. Factors that predisposed to failure included midcarpal wear and a history of scaphoid nonuion. The authors emphasized the importance of carefully inspecting the midcarpal joint at the time of surgery to ensure the quality of articular cartilage. Among 18 patients examined at follow-up flexion averaged 17”, extension 3 1” ulnar deviation 13”, and radial deviation 8”. Grip strength averaged 75% of the contralateral hand. Two of our five patients with radioscapholunate arthrodeses developed progressive, painful degenerative arthritis postoperatively and were ultimately converted to total arthrodesis. One of the failures was in the single stage III case in group 4. The postoperative dimunition of flexion and extension was higher for the radiocarpal arthrodeses than the scahoid excisions and PRCs. While the radioscaphoid (group 5) had good pain relief and none failed, it is difficult to make definitive inferences regarding the potential advantages of this procedure since there were only three cases. Since this is a retrospective review of several different surgical treatments for SLAC wrist, it suffers from flaws inherent in such a study design. Some of the groups are small, thus precluding statistical appraisal of the results. The groups also vary with respect to the predominant stage of disease represented in each. Despite these obvious limitations, we feel that our data demonstrate that motion-sparing procedures provide satisfactory pain relief and motion in the majority of patients with stage II and stage III SLAC wrist and that scaphoid excision and intercarpal arthrodesis is the procedure of choice for stage III SLAC wrist. In addition, PRC gives the best motion but is associated with painful narrowing of the radiocapitate joint, and is best indicated in stage II SLAC where the articular surfaces of the capitate head and lunate fossa are intact. Finally, while in our study radioscapholunate fusion had the lowest success rate of all procedures and radiosca-
phoid fusion the highest, the difference in outcome between the two groups may be due to small sample size.
References Watson HK, Ballet FL. The SLAC wrist: scapholunate advanced collapse pattern of degenerative arthritis. J Hand Surg 1984;9A:358-65. 2. Vender MI, Watson HK, Wiener BD, Black DM. Degenerative change in symptomatic scaphoid nonI.
union. J Hand Surg 1987;12A:514-9. VP, Kang HS, Resnick D, Sartoris DJ, Haller J. Scapholunate advanced collapse: a common wrist abnormality in calcium pyrophosphate dihydrate deposition disease. Radiology 1990;2: 459-61. 4. Resnick D, Niwayama G. Carpal instability in rheumatoid arthritis and calcium pyrophosphate depostion disease: pathogenesis and roentgen appearance. Ann Rheum Dis 1977;36:31 l-8. 5. Fassler PR, Stern PJ, Kiefhaber TR. Asymptoamtic SLAC wrist: does it exist? J Hand Surg 1993;18A: 682-6. 6. Kleinert JM, Stern PJ, Lister GD, Kleinhaus RJ. Complications of scaphoid silicone arthroplaty. J Bone Joint Surg 1985:67A:422-7. Smith RJ, Atkinson RE, Jupiter JB. Silicone synovitis of the wrist. J Hand Surg 1985;10A:47-60. Crabbe WA. Excision of the proximal row of the carpus. J Bone Joint Surg 1964;46B:708-11. Ferlic DC, Clayton MC, Mills MF. Proximal row carpectomy: review of rheumatoid and nonrheumatoid wrists. J Hand Surg 1991;16A:420-4. 10. Harris WH, Jones WN, Aufranc OE. Problem cases from fracture gand rounds at the Massachusetts General Hospital. St Louis: Mosby, 1965:291. 11. Imbriglia JE, Broudy AS, Hagberg WC, McKernan D. Proximal row carpectomy: clinical evaluation. J Hand Surg 1990:15A:426-30. 12. Inglis AE, Jones EC. Proximal row carpectomy for diseases of the proximal row. J Bone Joint Surg 1977; 59A:460-3. 13. Jorgensen EC. Proximal row carpectomy: an end result of twenty-two cases. J Bone Joint Surg 1%9;51A: 1104-l. 14. Neviaser RJ. Proximal row carpectomy for post-traumatic disorders of the carpus. J Hand Surg 1983;8: 301-5. 15. Neviaser RJ. On resection of the proximal carpal row. Clin Orthop 1986;202: 12-5. 16. Culp RW, McGuigan FX, Turner MA, Lichtman DM, Osterman AL, McCarroll HR. Proximal row carpectomy: a multicenter study. J Hand Surg 1993;18A: 19-25. 17. Bach A, Almquist E, Newman D. Proximal row fusion as a solution for radiocarpal arthritis. J Hand Surg 1991;16A:424-31. 18. Gordon LH, King D. Partial wrist arthrodesis for old
3. Chen C, Chandnani
The Journal of Hand Surgery i Vol. 19A No. 5 September 19’14 759
19. 20. 21.
22.
23.
ununited fractures of the carpal navicular. Am J Surg 1961:102:460-4. Minami A, Ogino T, Minami M. Limited wrist fusions. J Hand Surg 1988;13A:660-7. Schwartz S. Localized fusion at the wrist joint. J Bone Joint Surgery 1967;49A:l591-6. Watson HK, Goodman ML, Johnson TR. Limited wrist arthrodesis. Part II: Intercarpal and radiocarpal combinations. J Hand Surg 1981;6:223-33. Viegas SF, Patterson RM, Peterson PD, et al. Evaluation of the biomechanical efficacy of limited intercarpal fusions for the treatment of scapho-lunate dissociation. J Hand Surg 1990:15A: 120-8. Kirschenbaum D, Schneider LH. Kirkpatrick WH, Adams DC, Cody RP. Scaphoid excision and capi-
24. 35. 26.
27.
28.
tolunate arthrodesis for radioscaphoid arthritis. J Hand Surg 1993:18A:780-5. Campbell CJ, Keokarn T. Total and subtotal arthrodesisofthe wrist. J Bone Joint Surg 1964:46A: 1520-33. Clayton ML, Ferlic DC. Arthrodesis of the arthritic wrist. Clin Orthop 1984:187:89-93. Palmer AK, Werner F, Murphy D, Glisson R. Functional wrist motion: a biomechanical study. J Hand Surg 1985:10A:39-46. Brumfield R. Nickel V. Nickel E. Joint motion in wrist flexion and extension. South Med J 1966:59: 909-10. Ryu J. Cooney WP, Askew LJ, An K. Chao EYS. Functional ranges of motion of the wrist joint. J Hand Surg 1991;16A:409-19.