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Factors affecting the outcome in 50 cases of scaphoid nonunion treated with Herbert screw fixation
cess rates fe to be relate actor of time a avascular necrosis and a history 0 roup with au intact cartil ete eneous nature of amy se 0111 ing results with cohorts u Jouzxal of Hand Surgery (British and European The success of scaphoid grafting suppiemented with Herbert screw fixation (Herbert and Fisher, 1984) for the treatment of scaphoid nonunion has been reported by a number of authors (Barton, 1997; Cooney et ai, 1988; Daly et al, 1996; Man and Herbert, 1996; Nakamura et al, 1993; Radford et al, 1990; Warren-Smith and Barton, 1988). Though factors such as the duration of the nonunion, the site of the nonunion, vascularity of bone, presence of degenerative changes, previous failed surgery and failure to graft are identified as important determinants of outcome by many authors, results are invariably expressed as an overall success rate for a series that inevitably contains a heterogeneous group of patients. Unless the duration of nonunion and the proportion of cases in each series with proximal pole nonunions and avascuiar proximal fragments is known like will not be compared with like. We report our results for the treatment of scaphoid nonunions attempting to identify the factors that influenced the radiological and clinical outcome. TIENT Between 1988 and i996, 67 patients with scaphoid nonunions were surgically treated. Forty-eight patients with 50 nonunions responded to a request to return for follow-up. Forty-six were male and four were female. The mean age was 35 years (range, 17-62 years). The dominant wrist was involved in 29 patients. Twenty-six patients had no previous treatment for their injury and ‘19 patients had been immobilized in a plaster cast for variable periods from 2 to 12 weeks. The remaining five had had previous surgery for nonunion. All five had been treated with bone grafts and three had internal fixation as well. The indications for surgery were pain and/or weakness and to reduce the development or progression of late degenerative change. The duration of nonunion before operation was between 4 months and 25 years. For those cases treated within 5 years of injury the mean
Volume, 1998) 231% 5: 6X-682 duration of nonunion was 17.3 months. For the 14 cases with long term nonunions the mean duration was 13 years. All fractures at or distal to the waist of the scaphoid were exposed by an anterior approach nonunion surfaces were excised to health3 cancellous bone with small osteotomes and the resultant defect grafted wit trapezoidal corticocancellous wedge graft (Fisk. 4970; 1984) taken from the iliac crest. After preiiminary fixation with a K-wire, which provided a useful lever to manipulate the scaphoid for the application of the Herbert
scaphoid and the graft were transExed with a screw. Proximal pole fractures (Fig. 1) were app dorsally through the third extensor compartment After excision of the nonunion site a cancello from the distal radius was inserted and a retrogra ert screw (the mini screw in recent years) was inser hand. A group of patients with longstanding scaphoid nonunions and established radioscaphoid arthritis had an additional radial styloidectomy to excise the arthritic area of the radius, the scaphoid being dealt with as described above (Fig 2). In all cases an operative assessment of the vascular status of the proximal pole was made based on the observation of punctate bleeding (Green: 1985). Accepting the hmitations of this method, most of the nroximal poles identified as being ischaemic or avascular in this series probably had what is now described as a Class 1 avascular necrosis (Biichier and Nagy, i $95). At surgery a number of cases were found to have an intact cartilagi velope or a non-mobile firm fibrous union ( 1996). In these cases it unjustified to t nonunion apart and a screw was inserted without bone grafting. operatively 24 patients had plaster immobihzation for 2 weeks and were subsequently put into a removable wrist brace that they were encouraged to discard as soon as comfort permitted. Fifteen patients were i.mmobiBized in plaster for 6 TV8 weeks, eight were immobilized f~:orIO
Fig
!
(a) Appearance
oi‘ proximai pole nonunion 6 months after injury. At operarion. periormed through a dorsal appi-or;cn, ai: intacr cartilaginous envelope was found. A free hand retrograde Herbert screw was inserted without distributing the fracture site and wi!hc;ui graft. (b) Six months later ukon was secured.
to 12 weeks and or three :he regime was unclear. All patients had a minimum 4 month review with a range of 6 months to 9 years (mean, 4.5 years). At the latest folio-w up patients were assessed using the modified Cooney :-ating system (Jiranek et ai: 1992) which emphasizes both subjective and objective findings hysical examination included inspection and palpation of the wrist for tenderness and instability. The Rexion-extension arc of the wrist was measured with a goniometer and expressed as a percentage of the uninvolved wrist (in blatera! cases this was expressed as a percentage of normal). Grip strength was assessed with a Jamar dynamometer and was expressed as a percentage of the uninvolved wrist. All patients had radiological follow up to assess the status of union, screw position and presence or absence of degenerative changes. Subjective rating was based upon the patient’s opinion of the extent of restoration of function, the level and frequency of pain, the etkcts of decreased range of movement and grip strength on performance and patient satisfaction. Objective rating was based upon the quality of union, presence of osteoarthritis, range of movement and grip strength.
Each rating could attract a maxnnmn 3: 100 points. On the subjective rating > 90 points was considered excellent, 80 to 89 points good, ‘70to 79 potnts fair and less than 70 poor. On the objective rating 3 90 points was excellent: 75 to 89 points good, 55 to 74 fair and less than 55 poor.
As our particular interest was to !nvesiigsLe ihe effects of entified adverse factors on the success of scaphoid bone grafting; we initially separated patients into five groups depending upon the duration of the nonumon before treatment (Table 2>, The over& subjective an,d objective outcome scores for these groups are shown in Tables 3 and 4. For the series as a whole partial or complete bony union was achieved in 40 patients (80%). Excellent or good subjective scores were achieved !n 39 patients [78%) and excellent or good objective scores in 41 patients (82%).
6X2
Fig 2
(a) Appearance of a scaphoid nonunion of 15 years duration in a 3%year-old man with estabhshed radioscaphoid and scapholtinate arthrltis. (b) Treatment by radial styloidectomy> scaphoid bone graft and Herbert screw fixation led to union with good subjective and objective outcomes
Though patient numbers in each of the sub-groups selected are too small for statistical analysis, Table 4 reveals a distinct trend towards a decline in the attainment of union the longer the duration of nonunion: this trend being particularly evident after 5 years. For patients in groups A and B treated within 12 months of injury complete bony union was achieved in 18 out of 19 cases with excellent or good subjective results being achieved in 18 of the 19. In patients treated between 12 months and 5 years from nonunion (Groups C and D) partial or complete bony union was achieved in 14 out of 17 cases with excellent or good clinical results being achieved in ! 5 out of 17. In group E patients, treated more than 5 years after fracture 8 out of 14 achieved complete or partial bony union with only seven out of 14 reporting excellent or good subjective clinical results. Whether this observed decline is due to the duration of nonunion alone or whether other factors are at play requires closer analysis of the groups. Of the 19 cases in groups A and B, 14 had waist nonunions, five were proximal pole nonunions and an avascular proximal fragment was present in three. In groups C and D: there were 17 cases, 11 with waist nonunions, six with proximal pole nonunions and three with avascular proximal fragments. Group E contained
14 cases, 12 with waist nonunion~ two with proximal pole nonunions and seven with avascular proximal fragments. It can be seen that the case mix within these groups is not comparable and the influence of other suspected adverse factors needs to be examined.
Thirteen patients in the series had nonunion oC proxima: nole fractures. In five the proximal pole was avascuiar. k’leven of these 13 cases were treated withIn 5 years of injury. Union was achieved in ten patients, a!1 of whom had excellent or good clinical resuits. f the fiv-e patients with avascular proximal fragments two united and three failed to unite. Of the three failed unions two had poor clinical results and one a good clinical result. In this series there was no significant difference in outcome between waist and proximal pole injuries.
Thirteen cases were considered to have avascular proximal fragments. Five were proximal nonunions and eight were waist nonunions. A total of five progressed to union, two proximal pole and three waist nonunions. Of these cases one each in groups A, B and C had excellent results3 one _n group E had a good result and one also in group E had a poor result. Of the eight nonunions one each in group
583
Table I-Wrist
assessment using subjective and objeetivt ratings (Jiranek et al, 1992) -
Objective scale
Subjective scale
Union NOIK
10
Fibrous union Partial osseous union complete osseous union
15 20 2s
Function Limitation of all Unable to return Unable to return Able to return to Norma! activites
Rain
Complete Advanced Moderate Early None
Narcotic medication needed Pain every day Pain duriq gripping/impact ioadixg Aching aftfsr heavy work Aching more than once a month Aching less than a month No pain
(entire carpus)
Grip strength (as o/o normal) 26-50X IO 51-15% 15 76-100% 20 n’ormzl 25
Maxianum
possible score-100
of i?omnion
Gmp
Dwution
A %
< 6 months 5- 12 r~lonths
c
l-3 years 3- 5 years > 5 years
GiaU,!7
Grip strength Decrease limits performance Decrease doesn’t limit performance
10
Quality Quality
0 10
7
12 il
D
6
5
14
0
of life not improved of iife improved
Maximum possible score-100
dild D had fair results and one in gro3.p C and I‘ive in groq E had poor results. Our resul:s would confirm the presence of avascular necrosis as a major poor prognostic factor for both union and clinical outcome,
I 12 11 6 14
Five patients in OUT series had had previous nonunion. Two had undergone bone grafting
surgery for procedures
assessment for pain and function Pain*
_____
R
0
10
No. 9f pntients
iv
A
0 6 10 16 22 26 30
limits performance doesn’t limit performance
uration of ~~Q~~~~o~and number of patients in each group
Table 3--Sutijectiw
20 30 40
Osteoa~rthrosis
ange of motion (flex-ext arc as I/n norma%) z-5o:i, 10 Decrease 4 1&75% 15 Decrease 76-I OWL 20 Normal 25
14 E
0 10
activities to any work to previous job previous job
9
“-Refer ta Table 1. ‘*Indicates
6
10
10
1
~
1 1
1
3
22
26
-
1
2
3
~ 2 3
score: E=excellent;
30
0
~
5
1
3
4
2
5
2
2
I
2
I
-
2
2
3
5
6
G=good;
F=fair;
P=poor.
10
20
30
40
E
G
P
P
~
1
5
2
I
10
5
1
~~
8
3
i
1 -
3
6
6
3
2
4
2
4
3
3
4
2
i
6
alone and three had undergone bone grafting with screw fixation. Four of these cases: three in group E and one in group C, had moderate osteoarthritic changes preoperatively and all had avascular proximal fragments. None of these four united, all had poor clinical results and two have already had a wrist arthrodesis. 0ne patient in group I9 without osteoarthritis and with vascular fragments united with an excellent clinical result.
Eight patients were found to have an intact cartilaginous envelope or a firm fibrous union at surgery. These cases were fixed with a Herbert screw but the nonunion site was left undisturbed and not grafted (Fig 1). All were treated early, within 1 year of injury. Five nonunions were in the waist and three in the proximal pole. Two patients were considered to have avascular proximal fragments based upon the chalky white “‘drill obtained during preparation for screw fixation. Lulion and excellent or good clinical results were achieved in all.
idence of osteoarthriEleven patients had radiological e patient in group C tis on preoperative radiographs. had early radioscaphoid changes and had had a previous operation for nonunion which had failed and had an avascular proximal pole. Further operation again failed with a poor clinical result and he has since undergone an arthrodesis. The other ten patients represent a separate and distinct group; a:1 were in group E with longstanding nonunions of 5 to 25 years with a mean duration of 14.8 years. The mean age for this group was 42 years. Eight nonunions were in the waist and two in the proximal pole; avascular changes were found in the proximal pole of six patients. Before surgery ail had become more symptomatic, undoubtedly due to progression of degenerative changes. Radiologically ail had moderate changes affecting the radioscaphoid, scapholunate and scapho-
trapezia1 joints; the midcarpa! joint was considered healthy in all at the time of surgery. The aim of the operation was to preserve a mobile wrist. An appropriately sized radial styloidectomy was done. excising the whole of the arthritic styloid surface. The scaphoid was grafted and fixed with a Herbert screw. The alternative in a number of these patients would have been an arthrodesis. Five cases united, achieving excellent or good resuhs. The five who remained ununited all had avascular necrosis and poor results.
Individual cases of nonunion vary in the duration of nonunion, the position of fracture, the presence or absence of avascular necrosis or ischaemia, the presence of carpal collapse, the development of arthritic changes, a history of previous surgery or a combinations of these various adverse factors. Whereas most authors recognize and identify poor prognostic factors, the extent to which these Pd influenced the outcome 3s rarely analy rates of union after bone grafting and fixation have varied from 71(/o (Cooney et ai: 95% (Daly et al 1996). arton (1997) suggested ! ations in the criteria for union may explain the differences. We suspect that the ‘case mix’ of adverse factors in any given cohort of patients is equally itTIpOi%CIt and that variations in outcome are more a consequence of the influence of these factors than a reflection of the success of the technique. Nakamura et a! (1993) found that the inter-& between injury and treatment had a significant Muence on outcome, with excellent or good results being Eess likely when more than 5 years had elapsed since injury. Radford et al (1990) also felt that de!ay between injury and surgery was the major factor predisposing to failure and they felt that this ‘was related to the worsening vascularity of the proximal fragment with time. Daly et al (1996) found no relationship between the duration of nonunion and successful union in their series; however, 22 of their 26 cases were treated within 5 years of injury.
In our series 36 cases were treated within 5 years of injury with a union rate of 88%. Fourteen cases treated over 5 years from injury had a union rate of 57’s. Within each of these groups the proportion of proximai pole injuries varied (<5 years, Croups A-D: 11136; > 5 years, Group E: 2114). Although we accept that generally these cases have a poorer prognosis (Barton, 1997) in this series proximal pole injuries had no significant difference in outcome from waist injuries and as such have not influenced the overall union rates within these grQLlp§. When the distribution of patients thought to have ischaemic or avasc~~lar proximal fragments is examined it can be seen that numbers increase sequentially as the duration of nonunion increases (AR: 3/19, CD: 3/17, E: 7114). Of the ten cases in the whole series who failed to unite, eight were considered to have ischaemic or avascuBar proximal fragments confirming this as a major adverse prognostic factor. Indeed we feel that the infhrence of the duration of nonunion on the prognosis is purely due to the worsening vascularity of the proximal fragment with time rather than the parameter of time itself. We have been unab!e to reproduce the results of Robbins and Carter (1995) who secured bony union in nine of 1.7 cases with avascular proximal fragments and a LmctionaI fibrous union in a further seven with good or excellent clinical results in 11 of the 17 cases after bone grafting and Herbert screw fixation. They emphasized the need for supplementary plaster immobilization for a period of 3 months. Our cases with avascular necrosis were immobilized for periods of 4 to 12 weeks with a mean of 4 weeks. The results of Robbins and Carter would suggest that an extended period of splinting should be recommended for this difficult problem. The difficuities posed by revision surgery are well documented (Filan and Herbert, 1996). In our series five patients had undergone previous surgery for nonunion. Four were found to have avascular proximal fragments at operation and all failed to unite and had poor results. The other case with vascular fragments united with an excellent ciinical rest&. Daly et al (1996) were successful in securing union in ten out of 1 k patients who had undergone previous surgery. However, eight of these 11 cases had an initial operation for an acute fracture, not a nonunion. We feel there is a material difference between cases whose previous surgery was for an established nonunion and those treated for an acute fracture. Failure to bone graft in cases of scaphoid nonunion has been considered a common cause of failure (Fernandez, 1990; Herbert and Fisher, 1984; Nakamura et al, 1993) though Radford et al (1990) did not graft 42% of their nonunions and reported a 79O/ounion rate. We did not graft eight patients in our series. These were found to have an intact cartilaginous enve!ope or a firm
non- mobile fibrous
union at operation. X WerbeAAtscrew was inserted across the fracture in all without disturbing the fracture site. All progressed to bony union with exceilent or good clinical results. Barton (1996) suggested that in such cases the fracture site should be probed and windowed and presumably grafted. Our experience would suggest that this is unnecessary. A further distinct group within this series was the group of ten older patients with long established nonunions who had all developed moderate degenerative changes in the wrist. The presence of arthritis as such did not influence the outcome. Though five of these patients had a poor result all of them had an avascular proximal fragment which was the major factor mfluencing outcome. The other five ail had excellent or good results for what, in these cases, was a salvage procedure.
&ion N 1 11996). Apparentand partial Hand Surgery. 2 1B:496-500.
no~xuxon
of the scapiioid.
Journal
of
%:-ton N .I (1997). Experience with scaphoid grafting. .:o:mal of Hand Surgery, 22B: 153-! 60. Blichle: U, Nag! L (1995). The issue of vascularity m fi-acturcs and non-union of the scaphoid. Journal of Hand Surgery, 208: 726-735. Cooney W P. Linscheld R L: Dobyns J H. Wood M B (1988). Scaphold grafts. JOUI-nal of Hand nonunion: role of anterior interpositional Surgery. 13A. 635-650. Da:) K. Gill P. Magnusscn P. Simonis R B (1996). Establi&d nonunion of the scaphoid treated by v&r wedge grafting and Herbert screw fixation. Journal of Bone and Joint Surgery. 7SB: 530 -534 Fernander D L (1990). .4nterior bone grafting and cowentional !ag screw fixation to treat scaphoid nonunions. Journal of Hand Surgery. 15.4: 140-147. F:lan S L. Herbert T J (1996). Herbert screw fixation of scaphoid fractures. Journal of Belie and Joint Sul-guy. 7XB. 519-529 S~sk G R f 1970). Carnal instabllitv and the fractured scao!xo!d. Annals of the Ro;al Cbllegebf Surgeons bf England. 46, 63-76. ’ F~sx G R (1984). Non-union of the carpal scaphoid treated bq \%edge grafting. Journal of Bone and Joint Surgery. 66B: 277 i’;rcen 3 P 11985). The effect of axwular necrosis on Russe bone rrraftiw for scap’hoid honunion. Journal of Iiand Surgery. !!JA. 597-605.‘ herbert T .I, Fisher W E (1984). Management of :he fractured scaphoid usmg a new bone scxw. Journal of Bone and Join-t Surgery, 66B: 114-123. Jirdnek W A; Ruby L K, Mlllender L B. Bankof! M S. Newberg A H (1992). Long-term rssults after Russe grafting: ?he efi-ecectof malumon of the scaphoid. Journal of Bone and Joint Surger~~ 744. 1217-1228. \a:tamura R, Horii E, Watanabe K, Tsunoda K. Miura T (1993). Scaphoid nonunion: facto:-s affecting the functIonal outcome of open redixrion and wedge grafting with Herbert screen fixation. Jcurxil of Hand Surgery. IEB 219-224. Racford ? J, Mattiwwson M H. h4eggitt B F (1993). Hzbut screw for delayed and non-union of scaphold fractures: a review of lit’ty cases. Journal of Hand Surgery. 15B: 455459. Kosbins R R, Carter P R (3995). Iliac crest bone grafting and Herbert screw fmatlon of nonunions of the scaphoid \\ith avasc:liar proximal poles. Journal of Hand Surgery, 20A: 8 1X-S3 i U’airen.-Smith C D, Barton N J (1988). Non-union of the uaphoid: Ruse graft vs Kerbert screw. Journal of Hand Surgery. l?B. 83 86.
Volume, 1998) 231% 5: 6X-682 duration of nonunion was 17.3 months. For the 14 cases with long term nonunions the mean duration was 13 years. All fractures at or distal to the waist of the scaphoid were exposed by an anterior approach nonunion surfaces were excised to health3 cancellous bone with small osteotomes and the resultant defect grafted wit trapezoidal corticocancellous wedge graft (Fisk. 4970; 1984) taken from the iliac crest. After preiiminary fixation with a K-wire, which provided a useful lever to manipulate the scaphoid for the application of the Herbert
scaphoid and the graft were transExed with a screw. Proximal pole fractures (Fig. 1) were app dorsally through the third extensor compartment After excision of the nonunion site a cancello from the distal radius was inserted and a retrogra ert screw (the mini screw in recent years) was inser hand. A group of patients with longstanding scaphoid nonunions and established radioscaphoid arthritis had an additional radial styloidectomy to excise the arthritic area of the radius, the scaphoid being dealt with as described above (Fig 2). In all cases an operative assessment of the vascular status of the proximal pole was made based on the observation of punctate bleeding (Green: 1985). Accepting the hmitations of this method, most of the nroximal poles identified as being ischaemic or avascular in this series probably had what is now described as a Class 1 avascular necrosis (Biichier and Nagy, i $95). At surgery a number of cases were found to have an intact cartilagi velope or a non-mobile firm fibrous union ( 1996). In these cases it unjustified to t nonunion apart and a screw was inserted without bone grafting. operatively 24 patients had plaster immobihzation for 2 weeks and were subsequently put into a removable wrist brace that they were encouraged to discard as soon as comfort permitted. Fifteen patients were i.mmobiBized in plaster for 6 TV8 weeks, eight were immobilized f~:orIO
Fig
!
(a) Appearance
oi‘ proximai pole nonunion 6 months after injury. At operarion. periormed through a dorsal appi-or;cn, ai: intacr cartilaginous envelope was found. A free hand retrograde Herbert screw was inserted without distributing the fracture site and wi!hc;ui graft. (b) Six months later ukon was secured.
to 12 weeks and or three :he regime was unclear. All patients had a minimum 4 month review with a range of 6 months to 9 years (mean, 4.5 years). At the latest folio-w up patients were assessed using the modified Cooney :-ating system (Jiranek et ai: 1992) which emphasizes both subjective and objective findings hysical examination included inspection and palpation of the wrist for tenderness and instability. The Rexion-extension arc of the wrist was measured with a goniometer and expressed as a percentage of the uninvolved wrist (in blatera! cases this was expressed as a percentage of normal). Grip strength was assessed with a Jamar dynamometer and was expressed as a percentage of the uninvolved wrist. All patients had radiological follow up to assess the status of union, screw position and presence or absence of degenerative changes. Subjective rating was based upon the patient’s opinion of the extent of restoration of function, the level and frequency of pain, the etkcts of decreased range of movement and grip strength on performance and patient satisfaction. Objective rating was based upon the quality of union, presence of osteoarthritis, range of movement and grip strength.
Each rating could attract a maxnnmn 3: 100 points. On the subjective rating > 90 points was considered excellent, 80 to 89 points good, ‘70to 79 potnts fair and less than 70 poor. On the objective rating 3 90 points was excellent: 75 to 89 points good, 55 to 74 fair and less than 55 poor.
As our particular interest was to !nvesiigsLe ihe effects of entified adverse factors on the success of scaphoid bone grafting; we initially separated patients into five groups depending upon the duration of the nonumon before treatment (Table 2>, The over& subjective an,d objective outcome scores for these groups are shown in Tables 3 and 4. For the series as a whole partial or complete bony union was achieved in 40 patients (80%). Excellent or good subjective scores were achieved !n 39 patients [78%) and excellent or good objective scores in 41 patients (82%).
6X2
Fig 2
(a) Appearance of a scaphoid nonunion of 15 years duration in a 3%year-old man with estabhshed radioscaphoid and scapholtinate arthrltis. (b) Treatment by radial styloidectomy> scaphoid bone graft and Herbert screw fixation led to union with good subjective and objective outcomes
Though patient numbers in each of the sub-groups selected are too small for statistical analysis, Table 4 reveals a distinct trend towards a decline in the attainment of union the longer the duration of nonunion: this trend being particularly evident after 5 years. For patients in groups A and B treated within 12 months of injury complete bony union was achieved in 18 out of 19 cases with excellent or good subjective results being achieved in 18 of the 19. In patients treated between 12 months and 5 years from nonunion (Groups C and D) partial or complete bony union was achieved in 14 out of 17 cases with excellent or good clinical results being achieved in ! 5 out of 17. In group E patients, treated more than 5 years after fracture 8 out of 14 achieved complete or partial bony union with only seven out of 14 reporting excellent or good subjective clinical results. Whether this observed decline is due to the duration of nonunion alone or whether other factors are at play requires closer analysis of the groups. Of the 19 cases in groups A and B, 14 had waist nonunions, five were proximal pole nonunions and an avascular proximal fragment was present in three. In groups C and D: there were 17 cases, 11 with waist nonunions, six with proximal pole nonunions and three with avascular proximal fragments. Group E contained
14 cases, 12 with waist nonunion~ two with proximal pole nonunions and seven with avascular proximal fragments. It can be seen that the case mix within these groups is not comparable and the influence of other suspected adverse factors needs to be examined.
Thirteen patients in the series had nonunion oC proxima: nole fractures. In five the proximal pole was avascuiar. k’leven of these 13 cases were treated withIn 5 years of injury. Union was achieved in ten patients, a!1 of whom had excellent or good clinical resuits. f the fiv-e patients with avascular proximal fragments two united and three failed to unite. Of the three failed unions two had poor clinical results and one a good clinical result. In this series there was no significant difference in outcome between waist and proximal pole injuries.
Thirteen cases were considered to have avascular proximal fragments. Five were proximal nonunions and eight were waist nonunions. A total of five progressed to union, two proximal pole and three waist nonunions. Of these cases one each in groups A, B and C had excellent results3 one _n group E had a good result and one also in group E had a poor result. Of the eight nonunions one each in group
583
Table I-Wrist
assessment using subjective and objeetivt ratings (Jiranek et al, 1992) -
Objective scale
Subjective scale
Union NOIK
10
Fibrous union Partial osseous union complete osseous union
15 20 2s
Function Limitation of all Unable to return Unable to return Able to return to Norma! activites
Rain
Complete Advanced Moderate Early None
Narcotic medication needed Pain every day Pain duriq gripping/impact ioadixg Aching aftfsr heavy work Aching more than once a month Aching less than a month No pain
(entire carpus)
Grip strength (as o/o normal) 26-50X IO 51-15% 15 76-100% 20 n’ormzl 25
Maxianum
possible score-100
of i?omnion
Gmp
Dwution
A %
< 6 months 5- 12 r~lonths
c
l-3 years 3- 5 years > 5 years
GiaU,!7
Grip strength Decrease limits performance Decrease doesn’t limit performance
10
Quality Quality
0 10
7
12 il
D
6
5
14
0
of life not improved of iife improved
Maximum possible score-100
dild D had fair results and one in gro3.p C and I‘ive in groq E had poor results. Our resul:s would confirm the presence of avascular necrosis as a major poor prognostic factor for both union and clinical outcome,
I 12 11 6 14
Five patients in OUT series had had previous nonunion. Two had undergone bone grafting
surgery for procedures
assessment for pain and function Pain*
_____
R
0
10
No. 9f pntients
iv
A
0 6 10 16 22 26 30
limits performance doesn’t limit performance
uration of ~~Q~~~~o~and number of patients in each group
Table 3--Sutijectiw
20 30 40
Osteoa~rthrosis
ange of motion (flex-ext arc as I/n norma%) z-5o:i, 10 Decrease 4 1&75% 15 Decrease 76-I OWL 20 Normal 25
14 E
0 10
activities to any work to previous job previous job
9
“-Refer ta Table 1. ‘*Indicates
6
10
10
1
~
1 1
1
3
22
26
-
1
2
3
~ 2 3
score: E=excellent;
30
0
~
5
1
3
4
2
5
2
2
I
2
I
-
2
2
3
5
6
G=good;
F=fair;
P=poor.
10
20
30
40
E
G
P
P
~
1
5
2
I
10
5
1
~~
8
3
i
1 -
3
6
6
3
2
4
2
4
3
3
4
2
i
6
alone and three had undergone bone grafting with screw fixation. Four of these cases: three in group E and one in group C, had moderate osteoarthritic changes preoperatively and all had avascular proximal fragments. None of these four united, all had poor clinical results and two have already had a wrist arthrodesis. 0ne patient in group I9 without osteoarthritis and with vascular fragments united with an excellent clinical result.
Eight patients were found to have an intact cartilaginous envelope or a firm fibrous union at surgery. These cases were fixed with a Herbert screw but the nonunion site was left undisturbed and not grafted (Fig 1). All were treated early, within 1 year of injury. Five nonunions were in the waist and three in the proximal pole. Two patients were considered to have avascular proximal fragments based upon the chalky white “‘drill obtained during preparation for screw fixation. Lulion and excellent or good clinical results were achieved in all.
idence of osteoarthriEleven patients had radiological e patient in group C tis on preoperative radiographs. had early radioscaphoid changes and had had a previous operation for nonunion which had failed and had an avascular proximal pole. Further operation again failed with a poor clinical result and he has since undergone an arthrodesis. The other ten patients represent a separate and distinct group; a:1 were in group E with longstanding nonunions of 5 to 25 years with a mean duration of 14.8 years. The mean age for this group was 42 years. Eight nonunions were in the waist and two in the proximal pole; avascular changes were found in the proximal pole of six patients. Before surgery ail had become more symptomatic, undoubtedly due to progression of degenerative changes. Radiologically ail had moderate changes affecting the radioscaphoid, scapholunate and scapho-
trapezia1 joints; the midcarpa! joint was considered healthy in all at the time of surgery. The aim of the operation was to preserve a mobile wrist. An appropriately sized radial styloidectomy was done. excising the whole of the arthritic styloid surface. The scaphoid was grafted and fixed with a Herbert screw. The alternative in a number of these patients would have been an arthrodesis. Five cases united, achieving excellent or good resuhs. The five who remained ununited all had avascular necrosis and poor results.
Individual cases of nonunion vary in the duration of nonunion, the position of fracture, the presence or absence of avascular necrosis or ischaemia, the presence of carpal collapse, the development of arthritic changes, a history of previous surgery or a combinations of these various adverse factors. Whereas most authors recognize and identify poor prognostic factors, the extent to which these Pd influenced the outcome 3s rarely analy rates of union after bone grafting and fixation have varied from 71(/o (Cooney et ai: 95% (Daly et al 1996). arton (1997) suggested ! ations in the criteria for union may explain the differences. We suspect that the ‘case mix’ of adverse factors in any given cohort of patients is equally itTIpOi%CIt and that variations in outcome are more a consequence of the influence of these factors than a reflection of the success of the technique. Nakamura et a! (1993) found that the inter-& between injury and treatment had a significant Muence on outcome, with excellent or good results being Eess likely when more than 5 years had elapsed since injury. Radford et al (1990) also felt that de!ay between injury and surgery was the major factor predisposing to failure and they felt that this ‘was related to the worsening vascularity of the proximal fragment with time. Daly et al (1996) found no relationship between the duration of nonunion and successful union in their series; however, 22 of their 26 cases were treated within 5 years of injury.
In our series 36 cases were treated within 5 years of injury with a union rate of 88%. Fourteen cases treated over 5 years from injury had a union rate of 57’s. Within each of these groups the proportion of proximai pole injuries varied (<5 years, Croups A-D: 11136; > 5 years, Group E: 2114). Although we accept that generally these cases have a poorer prognosis (Barton, 1997) in this series proximal pole injuries had no significant difference in outcome from waist injuries and as such have not influenced the overall union rates within these grQLlp§. When the distribution of patients thought to have ischaemic or avasc~~lar proximal fragments is examined it can be seen that numbers increase sequentially as the duration of nonunion increases (AR: 3/19, CD: 3/17, E: 7114). Of the ten cases in the whole series who failed to unite, eight were considered to have ischaemic or avascuBar proximal fragments confirming this as a major adverse prognostic factor. Indeed we feel that the infhrence of the duration of nonunion on the prognosis is purely due to the worsening vascularity of the proximal fragment with time rather than the parameter of time itself. We have been unab!e to reproduce the results of Robbins and Carter (1995) who secured bony union in nine of 1.7 cases with avascular proximal fragments and a LmctionaI fibrous union in a further seven with good or excellent clinical results in 11 of the 17 cases after bone grafting and Herbert screw fixation. They emphasized the need for supplementary plaster immobilization for a period of 3 months. Our cases with avascular necrosis were immobilized for periods of 4 to 12 weeks with a mean of 4 weeks. The results of Robbins and Carter would suggest that an extended period of splinting should be recommended for this difficult problem. The difficuities posed by revision surgery are well documented (Filan and Herbert, 1996). In our series five patients had undergone previous surgery for nonunion. Four were found to have avascular proximal fragments at operation and all failed to unite and had poor results. The other case with vascular fragments united with an excellent ciinical rest&. Daly et al (1996) were successful in securing union in ten out of 1 k patients who had undergone previous surgery. However, eight of these 11 cases had an initial operation for an acute fracture, not a nonunion. We feel there is a material difference between cases whose previous surgery was for an established nonunion and those treated for an acute fracture. Failure to bone graft in cases of scaphoid nonunion has been considered a common cause of failure (Fernandez, 1990; Herbert and Fisher, 1984; Nakamura et al, 1993) though Radford et al (1990) did not graft 42% of their nonunions and reported a 79O/ounion rate. We did not graft eight patients in our series. These were found to have an intact cartilaginous enve!ope or a firm
non- mobile fibrous
union at operation. X WerbeAAtscrew was inserted across the fracture in all without disturbing the fracture site. All progressed to bony union with exceilent or good clinical results. Barton (1996) suggested that in such cases the fracture site should be probed and windowed and presumably grafted. Our experience would suggest that this is unnecessary. A further distinct group within this series was the group of ten older patients with long established nonunions who had all developed moderate degenerative changes in the wrist. The presence of arthritis as such did not influence the outcome. Though five of these patients had a poor result all of them had an avascular proximal fragment which was the major factor mfluencing outcome. The other five ail had excellent or good results for what, in these cases, was a salvage procedure.
&ion N 1 11996). Apparentand partial Hand Surgery. 2 1B:496-500.
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