SCIENTIFIC ARTICLE
Radiocapitate Congruency as a Predictive Factor for the Results of Proximal Row Carpectomy Hubert Lenoir, MD, Adriano Toffoli, MSc, Bertrand Coulet, PhD, Cyril Lazerges, MD, Thomas Waitzenegger, MD, Michel Chammas, PhD
Purpose To evaluate whether the congruency between the joint surfaces of the lunate fossa of the distal radius and the proximal capitate might be a prognostic factor for functional, clinical, or radiographic results after proximal row carpectomy (PRC). Methods After reconstructing the computed tomographic arthrogram of patients with PRC, we evaluated the shape of the proximal capitate by measuring the radius of curvature of the tip of the capitate. The congruency of the future radiocapitate joint was then evaluated by the radiocapitate index in the frontal and sagittal planes. This was calculated by dividing the radius of curvature of the tip of the capitate by the mean radius of curvature of the lunate fossa. We determined the relationship between these morphological results and the functional (Disabilities of the Arm, Shoulder, and Hand [DASH] score, Mayo Wrist score, and pain relief), clinical (mobility and strength) and x-ray results (radiocapitate arthrosis). Results A total of 27 patients were reviewed at a mean follow-up of 59 months. The shape of the proximal capitate did not affect outcomes. In the frontal plane, a better radiocapitate congruency was significantly associated with an increase in wrist flexion and better functional results for the DASH. There was a non-significant relationship between congruency and improvement of Mayo Wrist score and pain relief. In the sagittal plane, the DASH score tended to improve when congruency was better. Conclusions The shape of the capitate was not a prognostic factor for functional outcome after PRC. The radiocapitate index seems more relevant in predicting results at last follow-up. (J Hand Surg Am. 2015;40(6):1088e1094. Copyright Ó 2015 by the American Society for Surgery of the Hand. All rights reserved.) Type of study/level of evidence Prognostic II. Key words Proximal row carpectomy, functional results, radiocapitate, congruency, wrist osteoarthritis.
C
optimal surgical procedure for patients with stage II scapholunate advanced collapse or scaphoid nonunion advanced collapse. When degenerative ONTROVERSY EXISTS REGARDING THE
From the Hand and Upper Extremity Surgery Unit, CHRU Montpellier University Hospital, Montpellier, France. Received for publication February 11, 2014; accepted in revised form February 10, 2015. No benefits in any form have been received or will be received related directly or indirectly to the subject of this article. Corresponding author: Hubert Lenoir, MD, Service de Chirurgie de la Main et du Membre Supérieur, CHU Lapeyronie, 371 Avenue du Doyen Gaston Giraud, 34295 Montpellier Cedex 5, France; e-mail: [email protected]. 0363-5023/15/4006-0003$36.00/0 http://dx.doi.org/10.1016/j.jhsa.2015.02.019
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radioscaphoid lesions are present, the 2 possible choices are proximal row carpectomy (PRC) or partial wrist fusion (PWF) with scaphoid excision.1 Proximal row carpectomy is technically less demanding and requires a shorter postoperative immobilization time.1,2 It seems to be associated with fewer complications because of the absence of implant-related complications or nonunion.1e4 Better ranges of flexion-extension have also been reported with this procedure compared with PWF.3,4 Conversely, PRC induces a loss of strength owing to relative lengthening of the flexor tendons.5,6 Proximal row carpectomy is also more prone to arthrosis perhaps because of a lack of congruency, especially in young manual workers.2,5
RADIOCAPITATE CONGRUENCY AND PRC
Respective indications for PWF and PRC are currently mostly determined by the state of the cartilage on the proximal capitate and on the lunate fossa of the radius, patients’ age, and their activity level. The importance of radiocapitate congruency in PRC has been incompletely studied.7e9 We hypothesized that the morphological characteristics of the lunate fossa and capitate should be considered when choosing between a PRC or PWF in cases of radioscaphoid degenerative lesions or Kienböck disease. We always evaluate the radiocarpal and midcarpal cartilage lesions with a preoperative computed tomographic (CT) arthrogram when choosing between a PRC or a PWF. This allowed us to determine whether the shape of the proximal capitate and preoperative radiocapitate congruency were prognostic factors for the functional outcomes of PRC.
FIGURE 1: Distribution of joint landmarks evenly spaced over the lunate fossa of the radius (blue dots) and at the proximal capitate (yellow dots).
MATERIALS AND METHODS A total of 56 patients were treated by PRC from March 2004 to May 2010. Among these, 11 patients were lost to follow-up and 1 died. To attribute postoperative degenerative cartilage lesions to radiocapitate incongruency, we excluded all patients with cartilage damage of the proximal capitate or lunate fossa of the radius, even minor. Patients operated on in the context of neurological sequelae of the upper limb, those who had had another surgical procedure after PRC, and those who had not had a preoperative CT arthrogram were excluded. Minimum follow-up was 2 years. Twentyseven patients were included and evaluated by an independent observer. There were 20 men and 7 women, mean age 51 12 years at surgery. Twenty patients were manual workers. The dominant side was involved in 15 cases. There were 18 scapholunate advanced collapse wrists, 5 scaphoid nonunion advanced collapse wrists, and 4 cases of Kienböck disease. The carpus was exposed by a dorsal skin incision through the third extensor compartment. We performed a resection of the posterior interosseous nerve in all cases. A capsulotomy was made and the cartilage on the head of the capitate and on the lunate fossa was inspected. Proximal row carpectomy was thus carried out. We used no additional internal fixation to stabilize the wrist and performed no styloidectomy. The wrist was immobilized in a forearm plaster cast for 3 weeks, at which time wrist motion exercises and physiotherapy were started. At the last follow-up, we performed a subjective assessment of pain using a numerical scale of 0 to 10 under both stress and resting conditions. The Disabilities of the Arm, Shoulder, and Hand (DASH) J Hand Surg Am.
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score and Mayo Wrist Score (MWS) were recorded. Patient satisfaction was evaluated. We evaluated range of motion using a goniometer. Pinch strength and grip strength were measured using a Jamar dynamometer and compared with the contralateral side. Finally, anteroposterior and lateral radiographs of the wrist in neutral pronosupination were analyzed for radiocapitate arthrosis according to the classification of Culp et al10: grade I if no sign was present; grade II if there was moderate joint space narrowing; grade III for cases with an onset of subchondral sclerosis; and grade IV if there was joint destruction with complete narrowing, proximal capitate collapse, or subchondral cyst formation. Arthrosis was graded by an orthopedic surgeon blinded to the CT arthrogram and preoperative radiographs. The shape of the proximal capitate and the curvature radii of the lunate fossa and capitate were measured with preoperative CT arthrograms. Image data were transferred in DICOM format into Myrian software, version 1.8.3 (Intrasense, Paris, France). We retained scan slices on which there was the highest convexity for the capitate and the deepest concavity for the lunate fossa in the frontal and sagittal planes. After PRC, a point on the radial side of a slice can articulate with a point on the capitate side of a different slice. Thus, the radii of curvature on both sides were sometimes calculated on different slices. After identifying the joint surfaces, we recorded the digital coordinates for each joint surface on a succession of dots uniformly spaced at each millimeter (Fig. 1). r
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FIGURE 2: Intermediate radius of curvature rx for the lunate fossa of the radius. The average of all of these corresponds to the mean radius of curvature. Mean radius of curvature ¼ (r1 þ r2 þ r3 þ . þ rn)/n.
FIGURE 3: Intermediate radius of curvature rmin (red dots) on the tip of the joint surface of the capitate.
Working from the coordinates of these points taken 3 3, we then calculated an intermediate radius of curvature, rx, every millimeter. We assessed the shape of the lunate fossa with the mean radius of curvature (calculated with the average of these intermediates radius of curvature) (Fig. 2). Considering that a V-shaped and a more rounded capitate of the same size may have the same mean radius of curvature, we assessed the shape of the proximal capitate by the intermediate radius of curvature, rmin, on the tip of the joint surface of the capitate (Fig. 3). Thus, we considered that the more the capitates were V-shaped, the smaller this variable would be and the more spherical-shaped or flatter the capitates were, the greater the parameter would be. The radiocapitate index was determined by dividing rmin by the mean radius of curvature of the lunate fossa. This gave us an estimation of the congruency between the lunate fossa and the proximal capitate. The congruency was considered perfect if the ratio was equal to 1. The lower the ratio was, the lesser was the radiocapitate congruency. Most of the quantitative variables had a Gaussian distribution. Therefore, the statistical results are presented in the form of means and SDs. We calculated the coefficient of correlation between morphological parameters (ie, mean radius of J Hand Surg Am.
curvature of the lunate fossa, rmin, and radiocapitate indices) on the one hand and the clinical results (ie, pain, DASH score, MWS, satisfaction, range of motion, strength) and radiographical results (ie, radiocapitate arthrosis) on the other. Pearson or Spearman test was carried out according to whether the conditions for the Pearson test were respected. The significance threshold was fixed at 5% for all tests used. We obtained institutional review board approval for this retrospective study. RESULTS Table 1 lists the clinical results. According to the classification of Culp et al,10 11 wrists were classified as grade I, 11 were grade II (Fig. 4), 3 were grade III (Fig. 5), and 2 were grade IV. Of all 27 patients, 1 patient still had notable pain and has since undergone total wrist arthrodesis. Five cases of complex regional pain syndrome were reported. At the last follow-up, the vasomotor phenomena had disappeared in all patients. There were no cases of carpal subluxation or infection. No relationship was found between rmin, mean radius of curvature of the lunate fossa, and the clinical results. r
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TABLE 1.
Clinical Results Pain
Patient
Follow-Up, mo
1
29
8
2
46
2
3
50
0
4
47
5
5
97
6
37
7 8
Rest
Mobility
Effort
Strength (%)*
DASH
MWS
Satisfaction
F/E
RD/UD
Jamar
Pinch
9
67
15
DS
75
20
40
48
9
41
20
DS
35
0
88
83
7
25
45
DS
110
55
31
46
8
26
40
S
66
32
84
72
0
4
32
40
S
76
10
25
46
0
2
32
65
S
102
45
42
50
51
3
7
66
10
S
75
20
11
64
35
2
5
37
45
S
70
50
73
90
9
91
0
3
27
55
S
80
37
40
100
10
83
1
8
15
55
S
120
35
63
84
11
65
0
0
12
75
S
68
30
90
92
12
107
0
0
44
60
S
78
10
71
77
13
33
0
2
9
55
S
75
40
76
92
14
68
0
5
19
50
S
80
34
73
84
15
44
5
6
65
20
DS
74
30
63
74
16
58
0
0
3
60
S
80
40
50
74
17
57
0
0
9
60
S
62
10
73
85
18
94
0
0
3
65
S
55
30
69
75
19
44
0
0
2
90
S
84
35
100
80
20
72
0
0
40
75
S
83
40
75
87
21
51
0
1
2
80
S
90
32
87
90
22
56
0
0
0
75
S
71
35
74
83
23
41
0
0
4
75
S
90
30
72
78
24
78
0
0
0
90
S
90
32
100
80
25
54
0
2
5
75
S
117
47
54
81
26
53
0
0
9
80
S
100
42
69
80
27
60
0
0
1
75
S
75
30
65
80
Average
59
1
3
22
57
81
32
65
77
F/E, arc of flexion-extension; RD/UD, arc of radioulnar deviation; S, satisfied; DS, dissatisfied. *Relative to contralateral side.
In the frontal plane, the higher the radiocapitate index was, the better were the functional results for the DASH (r ¼ e0.572; P ¼ .045). A better radiocapitate congruency was also associated with an increase in wrist flexion (r ¼ 0.482; P ¼ .047). There was a nonsignificant relationship between congruency and improvement of MWS (r ¼ 0.415; P ¼ .058), pain relief (r ¼ e0.429; P ¼ .095), and wrist extension (r ¼ 0.341; P ¼ .087). In the sagittal plane, the increase in radiocapitate congruency had a non-significant relationship with the DASH (r ¼ e0.389; P ¼ .067) and pain (r ¼ e0.424; P ¼ .110). No other radiologic and clinical results were correlated with morphological parameters in the sagittal plane. J Hand Surg Am.
We found no relationship between morphological parameters and the onset of arthrosis at the last follow-up. DISCUSSION The overall results of our study are consistent with those of Lecomte et al6 and Dacho et al,11 who reported an improvement in the painful symptomatology of 88% and 77% of patients, respectively, after PRC. In the latter study, the mean DASH score was 25 points and is therefore comparable with the 22 points obtained by our patients. Finally, the mean flexion-extension arc1,2,5,6,8,11 and mean grasp strength2,6 were also in agreement with the values reported by other authors. r
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FIGURE 4: Grade II radiocapitate arthrosis.
FIGURE 5: Grade III radiocapitate arthrosis. Note the flattening of the proximal capitate.
Proximal row carpectomy has been shown to be useful for the treatment of degenerative lesions of the wrist without midcarpal arthrosis. In cases of radioscaphoid arthrosis, a PWF can also be performed. The superiority of one of these interventions has not yet been demonstrated.4,8,12 With a long follow-up, both procedures provide good results.5,13,14 Dacho et al11 noted that mobility tended to be better after PRC whereas static strength was statistically greater after PWF. Those authors therefore recommended PRC only for patients for whom heavy manual work was not required and who preferred a shorter postoperative immobilization. Finally, Mulford et al15 conducted a meta-analysis of 52 articles: 1,358 PWF and 818 PRC were recorded. The flexion-extension arc was 75 on average for PRCs compared with 64 for PWFs. This difference was not significant. Strength, pain, and functional scores were comparable for both techniques. The relative risk of arthrosis was over 4 times greater for PRC but without no radiologic and clinical correlation. Conversely, the complication rate after PWF was higher. Treatment according to morphological characteristics of the wrist rather than demographic features would perhaps yield better results. Indeed, it has been shown that the lunate fossa and the proximal capitate
do not always match perfectly. Imbriglia et al16 estimated that on radiographic analysis the radius of curvature of the proximal capitate was about two thirds that of the lunate fossa in the frontal and sagittal plane. On 17 magnetic resonance imaging scans performed on healthy voluntary subjects, Hawkins-River et al17 defined this ratio to be 0.57 in the sagittal plane and 0.37 in the frontal plane. Finally, Tang et al18 measured the contact surface between the radius and the scaphoid and the lunate to be 130 mm2, whereas it was only 34 mm2 between the radius and the capitate after PRC. The consequence of this decrease in contact area is an increase in contact pressure. According to Hogan et al7 and Tang et al,18 this increase in pressure was 57% and 280%, respectively, of the initial value. In cases of a bad match between the lunate fossa and the proximal capitate, one can assume that a PWF might be preferred over a PRC. The consequences of these morphological variations on radiocapitate congruency had been postulated by Viegas et al,19,20 who differentiated 2 types of lunate: type I, in which no medial facet articulating with the hamate was present; and type II, in which there was a medial facet. In the latter case, the proximal pole of the capitate often has a crest. On 107
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specimens, Yazaki et al21 studied the anatomical variations of the capitate and highlighted flat, spherical, and V-shaped capitates. The V-shaped capitate always appear to be associated with a type II lunate in the Viegas classification and most often have a crest at their tip. After performing an experimental PRC on each of the 3 capitate types, the authors noted for this V-shaped type that the contact surface of the radiocapitate joint was smaller and that the pressure was greater than for other types. Like Hawkins-Rivers et al,17 we believe that only 3-dimensional imaging can evaluate the wrist’s morphology correctly. The shape of the proximal capitate does not seem to be a predictive factor for functional results after PRC. Indeed, we found no correlation between rmin and the clinical results. This is consistent with the biomechanical results of Tang et al,22 who evaluated the effect of capitate morphology after experimental PRC. Comparing spherical and Vshaped types, the authors found no differences in contact area or contact pressure. In our in vivo study, we used a quantitative variable (rmin) to assess the shape of the proximal capitate, because sometimes it was difficult to classify capitates discretely into 3 groups. We consider that the lack of correlation between the shape of the proximal capitate and the clinical results may be the result of an adaptation of the proximal capitate. The V-shape likely becomes rounded. As a result, contact pressure decreases with time. Tang et al could not highlight this adaptation phenomenon in their cadaveric study. However, it is well documented in clinical studies: Jebson et al13 described this flattening phenomenon for 6 of their 20 patients after 10 years. Likewise, in a study using plain x-rays, Balk and Imbriglia23 compared the radius of curvature of the proximal capitate radiographically before PRC and at an average follow-up of 9 years. The ratio between the radius of curvature of the proximal capitate and the lunate fossa went from 64% to 72% in the frontal plane and 60% to 80% in the sagittal plane. The data presented do not make it possible to conclude whether adaptation of the proximal capitate is a predictive factor for clinical results or cartilage damage. Moreover, it remains unclear whether there are factors limiting this flattening. The radiocapitate index seems to be a prognostic factor for a better functional result after PRCs, particularly in the frontal plane. This index is more reliable than rmin because it takes into account both the shape of the capitate and of the lunate fossa of the radius. Variations in the radius of curvature of the lunate fossa are probably as important as variations in the shape of the capitate. These 2 articular surfaces were not evaluated in the same way. Regarding the J Hand Surg Am.
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lunate fossa, we used the mean radius of curvature because this one was always regular. Moreover, it was not possible to know preoperatively where the contact area of the proximal capitate with the lunate fossa would be. Finally, it was important to take into account the whole surface because there is a translation of the point of contact of the capitate head from the ulnar to the radial side of the lunate fossa and posteroanterior sliding during wrist motion after PRC.18,24 Regarding the shape of the proximal capitate, we used rmin rather than the mean radius of curvature because we postulated that a V-shaped and a more rounded capitate of the same size may have the same mean radius of curvature. We did not determine radii of curvature by creating best-fitting circles, like other authors,17,23 because this method can be applied only to circular surfaces and not to V-shaped capitate. However, the contact surface of the capitate may correlate with rmin only in situations where the wrist is in neutral. The fact that the rmin point may not be in contact with the lunate fossa at all times during wrist motion represents a limitation in our methodology. Although an improvement in radiocapitate index seems to be a good prognostic factor, it was not possible to establish a significant correlation for most clinical parameters. Similarly, we found no significant correlation between radiocapitate index in the sagittal plane and the clinical outcomes. We are not clearly able to explain why sagittal incongruency is better tolerated than frontal incongruency. Some of these results are explained because our study was based on static morphometric measurements and did not take into account the complex biomechanical motions of the wrist. It has been supposed that changes in kinematics may influence carpal loads and clinical results.16,18,24 An in vivo kinematic study would possibly explain the underlying mechanisms. Limitations of this study include a lack of longterm follow-up, which may have highlighted a relationship between radiocapitate incongruency and the onset of degenerative changes. However, the relationship between the onset of osteoarthritis and clinical outcomes after PRC is not yet fully understood.2,5,6,8,11 It is not possible to specify whether arthrosis will occur in patients with poor functional outcomes resulting from radiocapitate incongruency. ACKNOWLEDGMENT The authors thank Teresa Sawyers, Anne-Marie Ka, and Helen Nesbitt for helping with the English translation. r
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REFERENCES
12. Lukas B, Herter F, Englert A, Bäcker K. The treatment of carpal collapse: proximal row carpectomy or limited midcarpal arthrodesis? A comparative study. Handchir Mikrochir Plast Chir. 2003;35(5): 304e309. 13. Jebson PJ, Hayes EP, Engber WD. Proximal row carpectomy: a minimum 10-year follow-up study. J Hand Surg Am. 2003;28(4): 561e569. 14. Bain GI, Watts AC. The outcome of scaphoid excision and fourcorner arthrodesis for advanced carpal collapse at a minimum of ten years. J Hand Surg Am. 2010;35(5):719e725. 15. Mulford JS, Ceulemans LJ, Nam D, Axelrod TS. Proximal row carpectomy vs four corner fusion for scapholunate (Slac) or scaphoid nonunion advanced collapse (Snac) wrists: a systematic review of outcomes. J Hand Surg Eur Vol. 2009;34(2):256e263. 16. Imbriglia JE, Broudy AS, Hagberg WC, McKernan D. Proximal row carpectomy: clinical evaluation. J Hand Surg Am. 1990;15(3): 426e430. 17. Hawkins-Rivers S, Budoff JE, Ismaily SK, Noble PC, Haddad J. MRI study of the capitate, lunate, and lunate fossa with relevance to proximal row carpectomy. J Hand Surg Am. 2008;33(6):841e849. 18. Tang P, Gauvin J, Muriuki M, Pfaeffle JH, Imbriglia JE, Goitz RJ. Comparison of the “contact biomechanics” of the intact and proximal row carpectomy wrist. J Hand Surg Am. 2009;34(4):660e670. 19. Viegas SF. The lunatohamate joint of the midcarpal joint. Arthroscopy. 1990;6(1):5e10. 20. Viegas SF, Wagner K, Patterson R, Peterson P. Medial (hamate) facet of the lunate. J Hand Surg Am. 1990;15(4):564e571. 21. Yazaki N, Burns ST, Morris RP, Andersen CR, Patterson RM, Viegas SF. Variations of capitate morphology in the wrist. J Hand Surg Am. 2008;33(5):660e666. 22. Tang P, Swart E, Konopka G, Raskolnikov D, Katcherian C. Effect of capitate morphology on contact biomechanics after proximal row carpectomy. J Hand Surg Am. 2013;38(7):1340e1345. 23. Balk ML, Imbriglia J. Proximal row carpectomy: indications, surgical technique, and long-term results. Atlas Hand Clin. 2004;9: 177e185. 24. Blankenhorn BD, Pfaeffle HJ, Tang P, Robertson D, Imbriglia J, Goitz RJ. Carpal kinematics after proximal row carpectomy. J Hand Surg Am. 2007;32(1):37e46.
1. Tomaino MM, Miller RJ, Cole I, Burton RI. Scapholunate advanced collapse wrist: proximal row carpectomy or limited wrist arthrodesis with scaphoid excision? J Hand Surg Am. 1994;19(1):134e142. 2. Richou J, Chuinard C, Moineau G, Hanouz N, Hu W, Le Nen D. Proximal row carpectomy: long-term results. Chir Main. 2010;29(1): 10e15. 3. Laulan J, Bacle G, de Bodman C, et al. The arthritic wrist. II—The degenerative wrist: indications for different surgical treatments. Orthop Traumatol Surg Res. 2011;97(4 suppl):S37eS41. 4. Wyrick JD, Stern PJ, Kiefhaber TR. Motion-preserving procedures in the treatment of scapholunate advanced collapse wrist: proximal row carpectomy versus four-corner arthrodesis. J Hand Surg Am. 1995;20(6):965e970. 5. DiDonna ML, Kiefhaber TR, Stern PJ. Proximal row carpectomy: study with a minimum of ten years of follow-up. J Bone Joint Surg Am. 2004;86(11):2359e2365. 6. Lecomte F, Wavreille G, Limousin M, Strouk G, Fontaine C, Chantelot C. Proximal row carpectomy: 25 cases. Rev Chir Orthop Reparatrice Appar Mot. 2007;93(5):444e454. 7. Hogan CJ, McKay PL, Degnan GG. Changes in radiocarpal loading characteristics after proximal row carpectomy. J Hand Surg Am. 2004;29(6):1109e1113. 8. Cohen MS, Kozin SH. Degenerative arthritis of the wrist: proximal row carpectomy versus scaphoid excision and four-corner arthrodesis. J Hand Surg Am. 2001;26(1):94e104. 9. Vanhove W, De Vil J, Van Seymortier P, Boone B, Verdonk R. Proximal row carpectomy versus four-corner arthrodesis as a treatment for SLAC (scapholunate advanced collapse) wrist. J Hand Surg Eur Vol. 2008;33(2):118e125. 10. Culp RW, McGuigan FX, Turner MA, Lichtman DM, Osterman AL, McCarroll HR. Proximal row carpectomy: a multicenter study. J Hand Surg Am. 1993;18(1):19e25. 11. Dacho AK, Baumeister S, Germann G, Sauerbier M. Comparison of proximal row carpectomy and midcarpal arthrodesis for the treatment of scaphoid nonunion advanced collapse (SNAC-wrist) and scapholunate advanced collapse (SLAC-wrist) in stage II. J Plast Reconstr Aesthet Surg. 2008;61(10):1210e1218.
J Hand Surg Am.
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Radiocapitate Congruency as a Predictive Factor for the Results of Proximal Row Carpectomy Hubert Lenoir, MD, Adriano Toffoli, MSc, Bertrand Coulet, PhD, Cyril Lazerges, MD, Thomas Waitzenegger, MD, Michel Chammas, PhD
Purpose To evaluate whether the congruency between the joint surfaces of the lunate fossa of the distal radius and the proximal capitate might be a prognostic factor for functional, clinical, or radiographic results after proximal row carpectomy (PRC). Methods After reconstructing the computed tomographic arthrogram of patients with PRC, we evaluated the shape of the proximal capitate by measuring the radius of curvature of the tip of the capitate. The congruency of the future radiocapitate joint was then evaluated by the radiocapitate index in the frontal and sagittal planes. This was calculated by dividing the radius of curvature of the tip of the capitate by the mean radius of curvature of the lunate fossa. We determined the relationship between these morphological results and the functional (Disabilities of the Arm, Shoulder, and Hand [DASH] score, Mayo Wrist score, and pain relief), clinical (mobility and strength) and x-ray results (radiocapitate arthrosis). Results A total of 27 patients were reviewed at a mean follow-up of 59 months. The shape of the proximal capitate did not affect outcomes. In the frontal plane, a better radiocapitate congruency was significantly associated with an increase in wrist flexion and better functional results for the DASH. There was a non-significant relationship between congruency and improvement of Mayo Wrist score and pain relief. In the sagittal plane, the DASH score tended to improve when congruency was better. Conclusions The shape of the capitate was not a prognostic factor for functional outcome after PRC. The radiocapitate index seems more relevant in predicting results at last follow-up. (J Hand Surg Am. 2015;40(6):1088e1094. Copyright Ó 2015 by the American Society for Surgery of the Hand. All rights reserved.) Type of study/level of evidence Prognostic II. Key words Proximal row carpectomy, functional results, radiocapitate, congruency, wrist osteoarthritis.
C
optimal surgical procedure for patients with stage II scapholunate advanced collapse or scaphoid nonunion advanced collapse. When degenerative ONTROVERSY EXISTS REGARDING THE
From the Hand and Upper Extremity Surgery Unit, CHRU Montpellier University Hospital, Montpellier, France. Received for publication February 11, 2014; accepted in revised form February 10, 2015. No benefits in any form have been received or will be received related directly or indirectly to the subject of this article. Corresponding author: Hubert Lenoir, MD, Service de Chirurgie de la Main et du Membre Supérieur, CHU Lapeyronie, 371 Avenue du Doyen Gaston Giraud, 34295 Montpellier Cedex 5, France; e-mail: [email protected]. 0363-5023/15/4006-0003$36.00/0 http://dx.doi.org/10.1016/j.jhsa.2015.02.019
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radioscaphoid lesions are present, the 2 possible choices are proximal row carpectomy (PRC) or partial wrist fusion (PWF) with scaphoid excision.1 Proximal row carpectomy is technically less demanding and requires a shorter postoperative immobilization time.1,2 It seems to be associated with fewer complications because of the absence of implant-related complications or nonunion.1e4 Better ranges of flexion-extension have also been reported with this procedure compared with PWF.3,4 Conversely, PRC induces a loss of strength owing to relative lengthening of the flexor tendons.5,6 Proximal row carpectomy is also more prone to arthrosis perhaps because of a lack of congruency, especially in young manual workers.2,5
RADIOCAPITATE CONGRUENCY AND PRC
Respective indications for PWF and PRC are currently mostly determined by the state of the cartilage on the proximal capitate and on the lunate fossa of the radius, patients’ age, and their activity level. The importance of radiocapitate congruency in PRC has been incompletely studied.7e9 We hypothesized that the morphological characteristics of the lunate fossa and capitate should be considered when choosing between a PRC or PWF in cases of radioscaphoid degenerative lesions or Kienböck disease. We always evaluate the radiocarpal and midcarpal cartilage lesions with a preoperative computed tomographic (CT) arthrogram when choosing between a PRC or a PWF. This allowed us to determine whether the shape of the proximal capitate and preoperative radiocapitate congruency were prognostic factors for the functional outcomes of PRC.
FIGURE 1: Distribution of joint landmarks evenly spaced over the lunate fossa of the radius (blue dots) and at the proximal capitate (yellow dots).
MATERIALS AND METHODS A total of 56 patients were treated by PRC from March 2004 to May 2010. Among these, 11 patients were lost to follow-up and 1 died. To attribute postoperative degenerative cartilage lesions to radiocapitate incongruency, we excluded all patients with cartilage damage of the proximal capitate or lunate fossa of the radius, even minor. Patients operated on in the context of neurological sequelae of the upper limb, those who had had another surgical procedure after PRC, and those who had not had a preoperative CT arthrogram were excluded. Minimum follow-up was 2 years. Twentyseven patients were included and evaluated by an independent observer. There were 20 men and 7 women, mean age 51 12 years at surgery. Twenty patients were manual workers. The dominant side was involved in 15 cases. There were 18 scapholunate advanced collapse wrists, 5 scaphoid nonunion advanced collapse wrists, and 4 cases of Kienböck disease. The carpus was exposed by a dorsal skin incision through the third extensor compartment. We performed a resection of the posterior interosseous nerve in all cases. A capsulotomy was made and the cartilage on the head of the capitate and on the lunate fossa was inspected. Proximal row carpectomy was thus carried out. We used no additional internal fixation to stabilize the wrist and performed no styloidectomy. The wrist was immobilized in a forearm plaster cast for 3 weeks, at which time wrist motion exercises and physiotherapy were started. At the last follow-up, we performed a subjective assessment of pain using a numerical scale of 0 to 10 under both stress and resting conditions. The Disabilities of the Arm, Shoulder, and Hand (DASH) J Hand Surg Am.
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score and Mayo Wrist Score (MWS) were recorded. Patient satisfaction was evaluated. We evaluated range of motion using a goniometer. Pinch strength and grip strength were measured using a Jamar dynamometer and compared with the contralateral side. Finally, anteroposterior and lateral radiographs of the wrist in neutral pronosupination were analyzed for radiocapitate arthrosis according to the classification of Culp et al10: grade I if no sign was present; grade II if there was moderate joint space narrowing; grade III for cases with an onset of subchondral sclerosis; and grade IV if there was joint destruction with complete narrowing, proximal capitate collapse, or subchondral cyst formation. Arthrosis was graded by an orthopedic surgeon blinded to the CT arthrogram and preoperative radiographs. The shape of the proximal capitate and the curvature radii of the lunate fossa and capitate were measured with preoperative CT arthrograms. Image data were transferred in DICOM format into Myrian software, version 1.8.3 (Intrasense, Paris, France). We retained scan slices on which there was the highest convexity for the capitate and the deepest concavity for the lunate fossa in the frontal and sagittal planes. After PRC, a point on the radial side of a slice can articulate with a point on the capitate side of a different slice. Thus, the radii of curvature on both sides were sometimes calculated on different slices. After identifying the joint surfaces, we recorded the digital coordinates for each joint surface on a succession of dots uniformly spaced at each millimeter (Fig. 1). r
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FIGURE 2: Intermediate radius of curvature rx for the lunate fossa of the radius. The average of all of these corresponds to the mean radius of curvature. Mean radius of curvature ¼ (r1 þ r2 þ r3 þ . þ rn)/n.
FIGURE 3: Intermediate radius of curvature rmin (red dots) on the tip of the joint surface of the capitate.
Working from the coordinates of these points taken 3 3, we then calculated an intermediate radius of curvature, rx, every millimeter. We assessed the shape of the lunate fossa with the mean radius of curvature (calculated with the average of these intermediates radius of curvature) (Fig. 2). Considering that a V-shaped and a more rounded capitate of the same size may have the same mean radius of curvature, we assessed the shape of the proximal capitate by the intermediate radius of curvature, rmin, on the tip of the joint surface of the capitate (Fig. 3). Thus, we considered that the more the capitates were V-shaped, the smaller this variable would be and the more spherical-shaped or flatter the capitates were, the greater the parameter would be. The radiocapitate index was determined by dividing rmin by the mean radius of curvature of the lunate fossa. This gave us an estimation of the congruency between the lunate fossa and the proximal capitate. The congruency was considered perfect if the ratio was equal to 1. The lower the ratio was, the lesser was the radiocapitate congruency. Most of the quantitative variables had a Gaussian distribution. Therefore, the statistical results are presented in the form of means and SDs. We calculated the coefficient of correlation between morphological parameters (ie, mean radius of J Hand Surg Am.
curvature of the lunate fossa, rmin, and radiocapitate indices) on the one hand and the clinical results (ie, pain, DASH score, MWS, satisfaction, range of motion, strength) and radiographical results (ie, radiocapitate arthrosis) on the other. Pearson or Spearman test was carried out according to whether the conditions for the Pearson test were respected. The significance threshold was fixed at 5% for all tests used. We obtained institutional review board approval for this retrospective study. RESULTS Table 1 lists the clinical results. According to the classification of Culp et al,10 11 wrists were classified as grade I, 11 were grade II (Fig. 4), 3 were grade III (Fig. 5), and 2 were grade IV. Of all 27 patients, 1 patient still had notable pain and has since undergone total wrist arthrodesis. Five cases of complex regional pain syndrome were reported. At the last follow-up, the vasomotor phenomena had disappeared in all patients. There were no cases of carpal subluxation or infection. No relationship was found between rmin, mean radius of curvature of the lunate fossa, and the clinical results. r
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TABLE 1.
Clinical Results Pain
Patient
Follow-Up, mo
1
29
8
2
46
2
3
50
0
4
47
5
5
97
6
37
7 8
Rest
Mobility
Effort
Strength (%)*
DASH
MWS
Satisfaction
F/E
RD/UD
Jamar
Pinch
9
67
15
DS
75
20
40
48
9
41
20
DS
35
0
88
83
7
25
45
DS
110
55
31
46
8
26
40
S
66
32
84
72
0
4
32
40
S
76
10
25
46
0
2
32
65
S
102
45
42
50
51
3
7
66
10
S
75
20
11
64
35
2
5
37
45
S
70
50
73
90
9
91
0
3
27
55
S
80
37
40
100
10
83
1
8
15
55
S
120
35
63
84
11
65
0
0
12
75
S
68
30
90
92
12
107
0
0
44
60
S
78
10
71
77
13
33
0
2
9
55
S
75
40
76
92
14
68
0
5
19
50
S
80
34
73
84
15
44
5
6
65
20
DS
74
30
63
74
16
58
0
0
3
60
S
80
40
50
74
17
57
0
0
9
60
S
62
10
73
85
18
94
0
0
3
65
S
55
30
69
75
19
44
0
0
2
90
S
84
35
100
80
20
72
0
0
40
75
S
83
40
75
87
21
51
0
1
2
80
S
90
32
87
90
22
56
0
0
0
75
S
71
35
74
83
23
41
0
0
4
75
S
90
30
72
78
24
78
0
0
0
90
S
90
32
100
80
25
54
0
2
5
75
S
117
47
54
81
26
53
0
0
9
80
S
100
42
69
80
27
60
0
0
1
75
S
75
30
65
80
Average
59
1
3
22
57
81
32
65
77
F/E, arc of flexion-extension; RD/UD, arc of radioulnar deviation; S, satisfied; DS, dissatisfied. *Relative to contralateral side.
In the frontal plane, the higher the radiocapitate index was, the better were the functional results for the DASH (r ¼ e0.572; P ¼ .045). A better radiocapitate congruency was also associated with an increase in wrist flexion (r ¼ 0.482; P ¼ .047). There was a nonsignificant relationship between congruency and improvement of MWS (r ¼ 0.415; P ¼ .058), pain relief (r ¼ e0.429; P ¼ .095), and wrist extension (r ¼ 0.341; P ¼ .087). In the sagittal plane, the increase in radiocapitate congruency had a non-significant relationship with the DASH (r ¼ e0.389; P ¼ .067) and pain (r ¼ e0.424; P ¼ .110). No other radiologic and clinical results were correlated with morphological parameters in the sagittal plane. J Hand Surg Am.
We found no relationship between morphological parameters and the onset of arthrosis at the last follow-up. DISCUSSION The overall results of our study are consistent with those of Lecomte et al6 and Dacho et al,11 who reported an improvement in the painful symptomatology of 88% and 77% of patients, respectively, after PRC. In the latter study, the mean DASH score was 25 points and is therefore comparable with the 22 points obtained by our patients. Finally, the mean flexion-extension arc1,2,5,6,8,11 and mean grasp strength2,6 were also in agreement with the values reported by other authors. r
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FIGURE 4: Grade II radiocapitate arthrosis.
FIGURE 5: Grade III radiocapitate arthrosis. Note the flattening of the proximal capitate.
Proximal row carpectomy has been shown to be useful for the treatment of degenerative lesions of the wrist without midcarpal arthrosis. In cases of radioscaphoid arthrosis, a PWF can also be performed. The superiority of one of these interventions has not yet been demonstrated.4,8,12 With a long follow-up, both procedures provide good results.5,13,14 Dacho et al11 noted that mobility tended to be better after PRC whereas static strength was statistically greater after PWF. Those authors therefore recommended PRC only for patients for whom heavy manual work was not required and who preferred a shorter postoperative immobilization. Finally, Mulford et al15 conducted a meta-analysis of 52 articles: 1,358 PWF and 818 PRC were recorded. The flexion-extension arc was 75 on average for PRCs compared with 64 for PWFs. This difference was not significant. Strength, pain, and functional scores were comparable for both techniques. The relative risk of arthrosis was over 4 times greater for PRC but without no radiologic and clinical correlation. Conversely, the complication rate after PWF was higher. Treatment according to morphological characteristics of the wrist rather than demographic features would perhaps yield better results. Indeed, it has been shown that the lunate fossa and the proximal capitate
do not always match perfectly. Imbriglia et al16 estimated that on radiographic analysis the radius of curvature of the proximal capitate was about two thirds that of the lunate fossa in the frontal and sagittal plane. On 17 magnetic resonance imaging scans performed on healthy voluntary subjects, Hawkins-River et al17 defined this ratio to be 0.57 in the sagittal plane and 0.37 in the frontal plane. Finally, Tang et al18 measured the contact surface between the radius and the scaphoid and the lunate to be 130 mm2, whereas it was only 34 mm2 between the radius and the capitate after PRC. The consequence of this decrease in contact area is an increase in contact pressure. According to Hogan et al7 and Tang et al,18 this increase in pressure was 57% and 280%, respectively, of the initial value. In cases of a bad match between the lunate fossa and the proximal capitate, one can assume that a PWF might be preferred over a PRC. The consequences of these morphological variations on radiocapitate congruency had been postulated by Viegas et al,19,20 who differentiated 2 types of lunate: type I, in which no medial facet articulating with the hamate was present; and type II, in which there was a medial facet. In the latter case, the proximal pole of the capitate often has a crest. On 107
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specimens, Yazaki et al21 studied the anatomical variations of the capitate and highlighted flat, spherical, and V-shaped capitates. The V-shaped capitate always appear to be associated with a type II lunate in the Viegas classification and most often have a crest at their tip. After performing an experimental PRC on each of the 3 capitate types, the authors noted for this V-shaped type that the contact surface of the radiocapitate joint was smaller and that the pressure was greater than for other types. Like Hawkins-Rivers et al,17 we believe that only 3-dimensional imaging can evaluate the wrist’s morphology correctly. The shape of the proximal capitate does not seem to be a predictive factor for functional results after PRC. Indeed, we found no correlation between rmin and the clinical results. This is consistent with the biomechanical results of Tang et al,22 who evaluated the effect of capitate morphology after experimental PRC. Comparing spherical and Vshaped types, the authors found no differences in contact area or contact pressure. In our in vivo study, we used a quantitative variable (rmin) to assess the shape of the proximal capitate, because sometimes it was difficult to classify capitates discretely into 3 groups. We consider that the lack of correlation between the shape of the proximal capitate and the clinical results may be the result of an adaptation of the proximal capitate. The V-shape likely becomes rounded. As a result, contact pressure decreases with time. Tang et al could not highlight this adaptation phenomenon in their cadaveric study. However, it is well documented in clinical studies: Jebson et al13 described this flattening phenomenon for 6 of their 20 patients after 10 years. Likewise, in a study using plain x-rays, Balk and Imbriglia23 compared the radius of curvature of the proximal capitate radiographically before PRC and at an average follow-up of 9 years. The ratio between the radius of curvature of the proximal capitate and the lunate fossa went from 64% to 72% in the frontal plane and 60% to 80% in the sagittal plane. The data presented do not make it possible to conclude whether adaptation of the proximal capitate is a predictive factor for clinical results or cartilage damage. Moreover, it remains unclear whether there are factors limiting this flattening. The radiocapitate index seems to be a prognostic factor for a better functional result after PRCs, particularly in the frontal plane. This index is more reliable than rmin because it takes into account both the shape of the capitate and of the lunate fossa of the radius. Variations in the radius of curvature of the lunate fossa are probably as important as variations in the shape of the capitate. These 2 articular surfaces were not evaluated in the same way. Regarding the J Hand Surg Am.
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lunate fossa, we used the mean radius of curvature because this one was always regular. Moreover, it was not possible to know preoperatively where the contact area of the proximal capitate with the lunate fossa would be. Finally, it was important to take into account the whole surface because there is a translation of the point of contact of the capitate head from the ulnar to the radial side of the lunate fossa and posteroanterior sliding during wrist motion after PRC.18,24 Regarding the shape of the proximal capitate, we used rmin rather than the mean radius of curvature because we postulated that a V-shaped and a more rounded capitate of the same size may have the same mean radius of curvature. We did not determine radii of curvature by creating best-fitting circles, like other authors,17,23 because this method can be applied only to circular surfaces and not to V-shaped capitate. However, the contact surface of the capitate may correlate with rmin only in situations where the wrist is in neutral. The fact that the rmin point may not be in contact with the lunate fossa at all times during wrist motion represents a limitation in our methodology. Although an improvement in radiocapitate index seems to be a good prognostic factor, it was not possible to establish a significant correlation for most clinical parameters. Similarly, we found no significant correlation between radiocapitate index in the sagittal plane and the clinical outcomes. We are not clearly able to explain why sagittal incongruency is better tolerated than frontal incongruency. Some of these results are explained because our study was based on static morphometric measurements and did not take into account the complex biomechanical motions of the wrist. It has been supposed that changes in kinematics may influence carpal loads and clinical results.16,18,24 An in vivo kinematic study would possibly explain the underlying mechanisms. Limitations of this study include a lack of longterm follow-up, which may have highlighted a relationship between radiocapitate incongruency and the onset of degenerative changes. However, the relationship between the onset of osteoarthritis and clinical outcomes after PRC is not yet fully understood.2,5,6,8,11 It is not possible to specify whether arthrosis will occur in patients with poor functional outcomes resulting from radiocapitate incongruency. ACKNOWLEDGMENT The authors thank Teresa Sawyers, Anne-Marie Ka, and Helen Nesbitt for helping with the English translation. r
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REFERENCES
12. Lukas B, Herter F, Englert A, Bäcker K. The treatment of carpal collapse: proximal row carpectomy or limited midcarpal arthrodesis? A comparative study. Handchir Mikrochir Plast Chir. 2003;35(5): 304e309. 13. Jebson PJ, Hayes EP, Engber WD. Proximal row carpectomy: a minimum 10-year follow-up study. J Hand Surg Am. 2003;28(4): 561e569. 14. Bain GI, Watts AC. The outcome of scaphoid excision and fourcorner arthrodesis for advanced carpal collapse at a minimum of ten years. J Hand Surg Am. 2010;35(5):719e725. 15. Mulford JS, Ceulemans LJ, Nam D, Axelrod TS. Proximal row carpectomy vs four corner fusion for scapholunate (Slac) or scaphoid nonunion advanced collapse (Snac) wrists: a systematic review of outcomes. J Hand Surg Eur Vol. 2009;34(2):256e263. 16. Imbriglia JE, Broudy AS, Hagberg WC, McKernan D. Proximal row carpectomy: clinical evaluation. J Hand Surg Am. 1990;15(3): 426e430. 17. Hawkins-Rivers S, Budoff JE, Ismaily SK, Noble PC, Haddad J. MRI study of the capitate, lunate, and lunate fossa with relevance to proximal row carpectomy. J Hand Surg Am. 2008;33(6):841e849. 18. Tang P, Gauvin J, Muriuki M, Pfaeffle JH, Imbriglia JE, Goitz RJ. Comparison of the “contact biomechanics” of the intact and proximal row carpectomy wrist. J Hand Surg Am. 2009;34(4):660e670. 19. Viegas SF. The lunatohamate joint of the midcarpal joint. Arthroscopy. 1990;6(1):5e10. 20. Viegas SF, Wagner K, Patterson R, Peterson P. Medial (hamate) facet of the lunate. J Hand Surg Am. 1990;15(4):564e571. 21. Yazaki N, Burns ST, Morris RP, Andersen CR, Patterson RM, Viegas SF. Variations of capitate morphology in the wrist. J Hand Surg Am. 2008;33(5):660e666. 22. Tang P, Swart E, Konopka G, Raskolnikov D, Katcherian C. Effect of capitate morphology on contact biomechanics after proximal row carpectomy. J Hand Surg Am. 2013;38(7):1340e1345. 23. Balk ML, Imbriglia J. Proximal row carpectomy: indications, surgical technique, and long-term results. Atlas Hand Clin. 2004;9: 177e185. 24. Blankenhorn BD, Pfaeffle HJ, Tang P, Robertson D, Imbriglia J, Goitz RJ. Carpal kinematics after proximal row carpectomy. J Hand Surg Am. 2007;32(1):37e46.
1. Tomaino MM, Miller RJ, Cole I, Burton RI. Scapholunate advanced collapse wrist: proximal row carpectomy or limited wrist arthrodesis with scaphoid excision? J Hand Surg Am. 1994;19(1):134e142. 2. Richou J, Chuinard C, Moineau G, Hanouz N, Hu W, Le Nen D. Proximal row carpectomy: long-term results. Chir Main. 2010;29(1): 10e15. 3. Laulan J, Bacle G, de Bodman C, et al. The arthritic wrist. II—The degenerative wrist: indications for different surgical treatments. Orthop Traumatol Surg Res. 2011;97(4 suppl):S37eS41. 4. Wyrick JD, Stern PJ, Kiefhaber TR. Motion-preserving procedures in the treatment of scapholunate advanced collapse wrist: proximal row carpectomy versus four-corner arthrodesis. J Hand Surg Am. 1995;20(6):965e970. 5. DiDonna ML, Kiefhaber TR, Stern PJ. Proximal row carpectomy: study with a minimum of ten years of follow-up. J Bone Joint Surg Am. 2004;86(11):2359e2365. 6. Lecomte F, Wavreille G, Limousin M, Strouk G, Fontaine C, Chantelot C. Proximal row carpectomy: 25 cases. Rev Chir Orthop Reparatrice Appar Mot. 2007;93(5):444e454. 7. Hogan CJ, McKay PL, Degnan GG. Changes in radiocarpal loading characteristics after proximal row carpectomy. J Hand Surg Am. 2004;29(6):1109e1113. 8. Cohen MS, Kozin SH. Degenerative arthritis of the wrist: proximal row carpectomy versus scaphoid excision and four-corner arthrodesis. J Hand Surg Am. 2001;26(1):94e104. 9. Vanhove W, De Vil J, Van Seymortier P, Boone B, Verdonk R. Proximal row carpectomy versus four-corner arthrodesis as a treatment for SLAC (scapholunate advanced collapse) wrist. J Hand Surg Eur Vol. 2008;33(2):118e125. 10. Culp RW, McGuigan FX, Turner MA, Lichtman DM, Osterman AL, McCarroll HR. Proximal row carpectomy: a multicenter study. J Hand Surg Am. 1993;18(1):19e25. 11. Dacho AK, Baumeister S, Germann G, Sauerbier M. Comparison of proximal row carpectomy and midcarpal arthrodesis for the treatment of scaphoid nonunion advanced collapse (SNAC-wrist) and scapholunate advanced collapse (SLAC-wrist) in stage II. J Plast Reconstr Aesthet Surg. 2008;61(10):1210e1218.
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