Unstable phalangeal fractures: Treatment by A.D. screw and plate fixation A prospective study of fifty-two fresh traumatic unstable fractures of the proximal or middle phalanges of the hand in forty-seven patients was reviewed. All the fractures were fixed with A.O. miniature screws and plates. The overall results were not satisfactory and complications were frequent. Only 26.9% of the fractures had good results. Fractures associated with significant soft tissue injuries had very poor results. When the present series was compared with a comparable group of fractures fixed with Kirschner wires, there was no significant improvement in the results. The unsatisfactory outcome of this group of unstable fractures may be largely due to the frequent association with poor prognostic factors. (J HAl'D SURG 1991j16A:113·17.)
W. K. Pun, MCh(Orth), FRCSG, FRCSE, FRACS, S. P.Chow,MS,FRCSE,FACS, Y.C.So,FRCSG,FRCSE,FRACSG, K. D. K. Luk, MCh(Orth), FRCSG, FRCSE, FRACSG, W. K. Ngai, FRCSE, F. K. Ip, FRCSE, W. H. Peng, MBBS, C. Ng, OTR, and C. Crosby, MCSP, Hong Kong
Management of unstable digital fractures of the hand is difficult and the results are not always satisfactory." 2 From our previous prospective study,' the results of internal fixation of unstable digital fractures by Kirschner wires after open reduction were not satisfactory. We thought that this might be because the fixation was not rigid enough. The biomechanical study done by Massengill and associates" showed that plate and screw fixation afforded the greatest rigidity. We investigated whether a more rigid fixation by A.a. miniature screws and plates would improve our results. In addition, the then recent development of A.a. minicondylar plates' for fixation of phalangeal periarticular fractures had widened the application of the technique.
From the Department of Orthopaedic Surgery.' University of Hong Kong, Queen Mary Hospital. Hong Kong. Received for publication Oct. 18. 1989; accepted in revised form f-eb, 3. 1990. No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article. Reprint requests: W. K. Pun. MD. Department of Orthopaedic Surgery, University of Hong Kong, Queen Mary Hospital. Hong Kong. 3/1120337
Materials and methods We reviewed a prospective study of 52 fresh traumatic functionally unstable fractures of the proximal or middle phalanges of the hand in 47 patients admitted to the Department of Orthopaedic Surgery, University of Hong Kong between February 1987 and August 1988. A fracture was considered functionally unstable if "acceptable alignment" could not be obtained after two attempts of closed reduction or if more than 30% of the normal active motion of the adjacent joints could not be achieved without loss of reduction. 3 The criteria for "acceptable alignment" were determined by radiographs. Considering the functional recovery and cosmesis, we accepted 10 degrees of angulation in both planes (sagittal and coronal) except in metaphyseal regions in which 20 degrees angulation in the sagittal plane was accepted. We considered that at least 50% overlap at the fracture site was necessary for rapid bone healing. The area of contact was calculated by the "product" of the percentages of apposition at the fracture site as seen in the anteroposterior and lateral radiographs. No rotational deformity was accepted. All the fractures were stabilized by use of the technique of plate or lag screw fixation employed by the Association for the Study of Internal Fixation (ASIF). In the proximal phalanges,a middorsal or dorsolat-
TIlE JOURNAL OF HAND SURGERY
113
The Journal of 114
PI/II
HAND SURGERY
et al,
Table I. Overall results
Proximal phalanx Middle phalanx
Good
Fair
Poor
10 (27.8'70) 4 (25'70) 14 (26.9'70)
13 (36.1'70) 6 (37.5'70) 19 (36.5'70)
13 (36.1'70) 6 (37.5'70) 19 (36.5'70)
E
Table II. Results of screw fixation and plating _ _ _ _ _ _"--_G_o_o_d_
Fig. I. Minicondylar plate fixation for periarticular fracture.
Screw fixation
3 (30'70)
Plating
II
(26.2'70)
eral extensor splitting incision was used. The extensor tendon was repaired with fine Prolene sutures after internal fixation. Middle phalangeal fractures were exposed through a midlateral incision. All the fractures were exposed subperiosteally after the periosteum was incised and elevated, thus avoiding violation of the gliding space between the extensor tendon apparatus and the periosteum. In open fractures, the approach was modified according to the wounds. In minicondylar plate fixation (Fig. I), the proximal one third of the collateral ligament was sometimes partially elevated for proper positioning of the plate. Associated "significant soft tissues injuries," which included lacerations of tendons and digital nerves, or large skin defects requiring reconstruction such as skin grafting, were dealt with by standard methods at the same time. All the operations were done by experienced surgeons, with special emphasis on meticulous soft tissues handling. Peri operative antibiotics were used routinely. After operation the hand was elevated. Active mobilization was started in the early postoperative period i.e., day 2 after the operation, except when there were "significant soft tissue injuries" that required immobilization for protection. After the patients' discharge from hospital, outpatient physiotherapy and occupational therapy were continued, 3 to 4 times per week. The patients were seen regularly in a special clinic with radiological and clinical assessments. In general, patients were discharged when their improvement became static, which usually occurred about 8 weeks after the injury. All the patients were seen again for their final assessment 2
Fair 5 (50'70) 14 (33.3'70)
Poor
36 16 52
E
2 (20'70)
10
I7
42
(40.5'70)
Table III. Results of fractures with or without significant soft tissue injuries
Without significant soft tissue injuries With significant soft tissue injuries
Good
EI
Poor
Total
41.9'70
35.5'70
22.6'70
31
4.8'70
38.1'70
57.1'70
21
months after they had returned to work or resumed their daily activities, e.g., housewife. For those patients who required salvage procedures to improve their function, e.g., tenolysis, capsulotomy, etc., the assessment immediately preceeding the salvage procedure was used for analysis. We assessed the results by measuring the total active movement (TAM) of the digit. TAM is defined as the total active flexion range of the metacarpophalangeal (MP) and interphalangeal (lP) joints. The results were graded as follows: Good, TAM is greater than or equal to 210 degrees; fair, TAM is between 180 degrees and 210 degrees; and poor, TAM is less than 180 degrees. For the thumb, we used the assessment method proposed by Gingrass and associates" by measuring the total active flexion range of the MP and IP joints. 3 Results Forty-seven patients with 52 fractures were included in this study. Three patients had multiple fractures af-
Vol. 16A, No.1 January 1991
Unstable phalangeal fractures
115
Fig. 2. A-H, Miniplate fixation .
fecting the same hand . Forty-three patients were male and four were female. Their ages ranged from 16 to 77 years (average, 38.5). Thirty fractures occurred on the left side and 22 on the right. There were 36 proximal and 16 middle phalangeal fractures . The distribution of the above fractures was as follows : thumb, 8; index , 15; long , II; ring, 9; and small, 9. Of the 52 fractures, 19 were comminuted; 17 were transverse; 14 were oblique or spiral, and 2 were vertical split fractures. Thirty-two (61.5%) fractures were open and 20 were closed. Twenty-one (40.4%) had concomitant significant soft tissue injuries . There were 16 extensor tendon and 6 flexor tendon injuries. Five digital nerves were severed. Seven digits had extensive skin loss. Ten fractures were fixed with 1.5 mm or 2 mm screws. Thirty-three were treated with miniature plates (Fig. 2, A and B). The remaining nine periarticular fractures were fixed with minicondylar plates (Fig. I). The overall results are shown in (Table I). Using the chi-square method, there is no significant difference in the results between proximal and middle phalangeal fractures. The results of the fractures treated by plating or screw fixation alone are shown in Table II. The latter group of fractures showed slightly better results although the
difference is not statistically significant as assessed by the chi-square test. Comparison of the results was made between fractures with or without significant soft tissue injuries using the chi-square test (Table III). Fractures without significant soft tissue injuries have significantly better results (p = 0.009). There were nine complications related to either the technique of fixation or the implant itself. Penetration of the joint cavity by the blade of the minicondylar 'plate occurred in two digits . In two out of three fractures treated by plating, the plates were relatively large and wound dehiscence with exposure of the plate occurred . A broken plate was encountered in one patient before fracture healing. In another, dislodgement of the screw from the plate occurred. Inadequate fixation with loss of reduction was noticed in two fractures treated by screw fixation alone, this was probably the result of inappropriate selection of the implant. In retrospect, plate fixation should have been used in these two fractures. In addition to the above complications, unsatisfactory reduction was noticed in four digits because of the severe comminution. There were four nonunions and two infections . The two cases of infection were not associated with extensive skin loss. Six patients required
116
PIlII
The Journal of HAND SURGERY
et al,
Table IV. Results of fractures* fixed by two different techniques Good
Kirschner wire fixation
A.a. fixation
4t% 35.7%
I
Fair
Poor
Total
20.5% 39.3%
38.5% 25%
39 28
'Multiple fractures in the same hand and fractures associated with "significant soft tissue injuries" were excluded.
tenolysis or capsulotomy after the fracture had healed to improve the active motion of their digits. Finally, we compared the results of the present series with a previously reported group of comparable middle and proximal phalangeal fracture;': S which had been fixed by Kirschner wires (Table IV). The latter group of fractures had the same indications for open reduction and internal fixation as the present series. To draw a more significant conclusion, we minimized the number of factors in the two groups of fractures and made them more homogeneous. Multiple fractures in the saine hand and fractures associated with "significant soft tissue injuries" were excluded from the comparison because they were found to be poor prognostic factors from our previous prospective study.' The results of the present series were no better than those fixed by Kirschner wires. In fact, there is no significant difference in the results as assessed by the chi-square test.
Discussion This study is unique in that it is prospective and only unstable fractures are included in the study. In the literature, several studies"? have shown that the results of unstable metacarpal fractures fixed with A.a. screws and plates are satisfactory and this is also our experience. Therefore, we limited our study to the unstable phalangeal fractures, which are very challenging, difficult to manage and in which the results of Kirschner wire fixation are not satisfactory. In this study, the results of A.a. miniature plate and screw fixation for the same group of fractures are again not encouraging and complications are very frequent despite the operations being carefully done by experienced surgeons. In fact, there is no significant improvement in the results when the present technique of internal fixation is compared with Kirschner wire fixation (Table IV). There are several drawbacks in the design of the A.a. miniature plates and screws. The plates are sometimes too large compared to the small phalangeal bones, especially middle phalanges or phalanges in the small finger. The prominence of the head end of the condylar plate often causes impingement on the skin and the
contour of the plate itself does not always fit all phalanges well, consequently precise moulding with benders is required. The hexagonal screw head is bulky and interferes at the proximal phalanx with the gliding of the extensor tendon and the oblique bands. The present technique of fixation often requires more soft tissue dissection compared to Kirschner wire fixation and therefore increases the soft tissue trauma. Overall, the present technique of internal fixation is very demanding and permits no latitude. All these problems seem to outweigh the theoretical advantage of more rigid fixation provided by the A.a. plate and screw and frequently lead to complications. Similar experience had also been reported by Stem and colleagues." It is possible that the outcome of this group of unstable fractures is predetermined because to begin with they are complicated fractures and have frequent association with poor prognostic factors. In our previous prospective study,' "open fractures," "comminuted fractures," and "associated significant soft tissue injuries" all contributed to a poor prognosis. In the present group of unstable fractures, 61.5% were open; 40.4% had significant soft tissue injuries, and 36.5% were comminuted. It appears that the presence of these poor prognostic factors is more important than the method of fixation in determining the final results. 10. \I In fact, the results in Tables III and IV show the importance of the poor prognostic factors in determining the final results of the fractures. This may explain the marked difference in the results between the series of Dabezies and Schutte? and ours because comminuted fractures and fractures associated with significant soft tissue injuries were not included in the former series. REFERENCES I. James lIP. Fractures of the proximal and middle phalanges of the fingers. Acta Orthop Scand 1962;32:40112. 2. Green DP, Anderson JR. Closed reduction and percutaneous pin fixation of fractured phalanges. J Bone Joint Surg 1973;55A:1651-4. 3. Pun WK, Chow SP, So YC, et aI. A prospective study on 284 digital fractures of the hand. J HAND SURG 1989;14A:474-81. 4. Massengill ra, Alexander H, Langrana N, Mylod A. A phalangeal fracture model-quantitative analysis of rigidity and failure. J HAND SURG 1982;7A:264-70. 5. Buchler U, Fischer T. Use of a minicondylar plate for metacarpal and phalangeal periarticular injuries. Clin Orthop 1987;214:53-8. 6. Gingrass RP, Fehring BHT, Matloub H. Intraosseous wiring of complex hand fractures. Plast Reconstr Surg 1980;66:383-9(
Vol. 16A, No. I January 1991
7. Stern PJ, Wieser MJ, Reilly DO. Complications of plate fixation in the hand skeleton. Clin Orthop 1987;214:5965. 8. Ford OJ, El-Hadidi S, Lunn PO, Burke FD. Fractures of the metacarpals: Treatment by A.O. screw and plate fixation. J HAND SURG 1987;12B:34-7. 9. Dabczies EJ, Schutte JP. Fixation of metacarpal and phalangeal fractures with miniature plates and screws. J HAND SURG 1986;IIA:283-8.
Unstable phalangeal fractures
10. Hastings H. Unstable metacarpal and phalangeal fracture treatment with screws and plates. Clin Orthop 1987; 214:37-52. II. Huffaker WH, Wray RC, Weeks PM. Factors influencing final range of motion in the fingers after fractures of the hand. Plast Reconstr Surg 1979;63:82-7.
Rotating shaft avulsion amputations of the thumb In a three-year period twenty-nine patients were treated for rotating shaft avulsion amputations of the thumb. Twenty-three thumbs were considered suitable for replantation. A staged approach, consisting of primary replantation and secondary nerve grafting and tendon reconstruction, was used because of concern that survival rates would be low. Survival was achieved in nineteen of twenty-three replantations. At mean follow-up of 20.5 months grip strength was 94.6% of the unaffected side and key pinch was 77.1 '70. Five patients achieved a two-point discrimination less than five millimeters. Success was better anticipated and now a full reconstruction is carried out in a single-stage procedure. (J HAND SURG 1991jI6A:1l7-21.)
C. V. A. Bowen, MB, ChB, FRCSC, Toronto, Ont., J. Beveridge, MD, FRCSC, R. G. Milliken, MD, CM, FRCSC, and G. H. F. Johnston, MD, FRCSC, Saskatoon, Saskatchewan, Canada
In western Canada, traumatic amputations of the thumb are common. They almost invariably result from entanglement with the rotating shaft of agricultural power take-off" 2 couplings, when farmers are using their tractors to drive motorized machinery." Functionally, the injuries are potentially devastating since the thumb contributes so much to total hand function. The best form of reconstruction is replantation, but the literature has indicated that for these avulsion type From the Department of Orthopaedic Surgery, University Hospital, Saskatoon. Saskatchewan, Canada, Received for pubtication June 27. 1989; accepted in revised form Dee, 4, 1989, Although none of the authors have received or will receive benefits for personal or professionat use from a commercial party related directly or indirectly to the subject of this article. benefits have been or will be received but are directly solely to a research fund, foundation, educational institution, or other non-profit organization with which one or more of the authors are associated. Reprint requests: Dr. Vaughan Bowen, EN 10-243 Toronto General Hospital, 200 Elizabeth St. Toronto, Ont., Canada, M5G 2C4. 3/1120582
of amputations high survival rates might not be achieved. For this reason, in our hospital, avulsion amputations of the thumb have been managed with a twostaged reconstruction. The first stage aimed at achieving microvascular survival and the second stage was done for functional reconstruction of nerves and tendons. This article reviews the results of this management technique. Materials and methods A study was made of all patients with rotating shaft avulsion amputations of the thumb that were managed at the Univerity Hospital in Saskatoon over a 3-year period between January 1984 and February 1987. Hospital charts and radiologic files were reviewed and the following factors were analyzed: Data concerning patients and accidents, types of injury sustained, clinical management, and final outcome. Patients were then recalled and reviewed clinically. At follow-up patients were asked about pain, cold intolerance, and their ability to use the replanted digits. Thumbs were assessed for appearance, movement, strength and sensibility. TIlE JOURNAL OF HAND SURGERY
117
W. K. Pun, MCh(Orth), FRCSG, FRCSE, FRACS, S. P.Chow,MS,FRCSE,FACS, Y.C.So,FRCSG,FRCSE,FRACSG, K. D. K. Luk, MCh(Orth), FRCSG, FRCSE, FRACSG, W. K. Ngai, FRCSE, F. K. Ip, FRCSE, W. H. Peng, MBBS, C. Ng, OTR, and C. Crosby, MCSP, Hong Kong
Management of unstable digital fractures of the hand is difficult and the results are not always satisfactory." 2 From our previous prospective study,' the results of internal fixation of unstable digital fractures by Kirschner wires after open reduction were not satisfactory. We thought that this might be because the fixation was not rigid enough. The biomechanical study done by Massengill and associates" showed that plate and screw fixation afforded the greatest rigidity. We investigated whether a more rigid fixation by A.a. miniature screws and plates would improve our results. In addition, the then recent development of A.a. minicondylar plates' for fixation of phalangeal periarticular fractures had widened the application of the technique.
From the Department of Orthopaedic Surgery.' University of Hong Kong, Queen Mary Hospital. Hong Kong. Received for publication Oct. 18. 1989; accepted in revised form f-eb, 3. 1990. No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article. Reprint requests: W. K. Pun. MD. Department of Orthopaedic Surgery, University of Hong Kong, Queen Mary Hospital. Hong Kong. 3/1120337
Materials and methods We reviewed a prospective study of 52 fresh traumatic functionally unstable fractures of the proximal or middle phalanges of the hand in 47 patients admitted to the Department of Orthopaedic Surgery, University of Hong Kong between February 1987 and August 1988. A fracture was considered functionally unstable if "acceptable alignment" could not be obtained after two attempts of closed reduction or if more than 30% of the normal active motion of the adjacent joints could not be achieved without loss of reduction. 3 The criteria for "acceptable alignment" were determined by radiographs. Considering the functional recovery and cosmesis, we accepted 10 degrees of angulation in both planes (sagittal and coronal) except in metaphyseal regions in which 20 degrees angulation in the sagittal plane was accepted. We considered that at least 50% overlap at the fracture site was necessary for rapid bone healing. The area of contact was calculated by the "product" of the percentages of apposition at the fracture site as seen in the anteroposterior and lateral radiographs. No rotational deformity was accepted. All the fractures were stabilized by use of the technique of plate or lag screw fixation employed by the Association for the Study of Internal Fixation (ASIF). In the proximal phalanges,a middorsal or dorsolat-
TIlE JOURNAL OF HAND SURGERY
113
The Journal of 114
PI/II
HAND SURGERY
et al,
Table I. Overall results
Proximal phalanx Middle phalanx
Good
Fair
Poor
10 (27.8'70) 4 (25'70) 14 (26.9'70)
13 (36.1'70) 6 (37.5'70) 19 (36.5'70)
13 (36.1'70) 6 (37.5'70) 19 (36.5'70)
E
Table II. Results of screw fixation and plating _ _ _ _ _ _"--_G_o_o_d_
Fig. I. Minicondylar plate fixation for periarticular fracture.
Screw fixation
3 (30'70)
Plating
II
(26.2'70)
eral extensor splitting incision was used. The extensor tendon was repaired with fine Prolene sutures after internal fixation. Middle phalangeal fractures were exposed through a midlateral incision. All the fractures were exposed subperiosteally after the periosteum was incised and elevated, thus avoiding violation of the gliding space between the extensor tendon apparatus and the periosteum. In open fractures, the approach was modified according to the wounds. In minicondylar plate fixation (Fig. I), the proximal one third of the collateral ligament was sometimes partially elevated for proper positioning of the plate. Associated "significant soft tissues injuries," which included lacerations of tendons and digital nerves, or large skin defects requiring reconstruction such as skin grafting, were dealt with by standard methods at the same time. All the operations were done by experienced surgeons, with special emphasis on meticulous soft tissues handling. Peri operative antibiotics were used routinely. After operation the hand was elevated. Active mobilization was started in the early postoperative period i.e., day 2 after the operation, except when there were "significant soft tissue injuries" that required immobilization for protection. After the patients' discharge from hospital, outpatient physiotherapy and occupational therapy were continued, 3 to 4 times per week. The patients were seen regularly in a special clinic with radiological and clinical assessments. In general, patients were discharged when their improvement became static, which usually occurred about 8 weeks after the injury. All the patients were seen again for their final assessment 2
Fair 5 (50'70) 14 (33.3'70)
Poor
36 16 52
E
2 (20'70)
10
I7
42
(40.5'70)
Table III. Results of fractures with or without significant soft tissue injuries
Without significant soft tissue injuries With significant soft tissue injuries
Good
EI
Poor
Total
41.9'70
35.5'70
22.6'70
31
4.8'70
38.1'70
57.1'70
21
months after they had returned to work or resumed their daily activities, e.g., housewife. For those patients who required salvage procedures to improve their function, e.g., tenolysis, capsulotomy, etc., the assessment immediately preceeding the salvage procedure was used for analysis. We assessed the results by measuring the total active movement (TAM) of the digit. TAM is defined as the total active flexion range of the metacarpophalangeal (MP) and interphalangeal (lP) joints. The results were graded as follows: Good, TAM is greater than or equal to 210 degrees; fair, TAM is between 180 degrees and 210 degrees; and poor, TAM is less than 180 degrees. For the thumb, we used the assessment method proposed by Gingrass and associates" by measuring the total active flexion range of the MP and IP joints. 3 Results Forty-seven patients with 52 fractures were included in this study. Three patients had multiple fractures af-
Vol. 16A, No.1 January 1991
Unstable phalangeal fractures
115
Fig. 2. A-H, Miniplate fixation .
fecting the same hand . Forty-three patients were male and four were female. Their ages ranged from 16 to 77 years (average, 38.5). Thirty fractures occurred on the left side and 22 on the right. There were 36 proximal and 16 middle phalangeal fractures . The distribution of the above fractures was as follows : thumb, 8; index , 15; long , II; ring, 9; and small, 9. Of the 52 fractures, 19 were comminuted; 17 were transverse; 14 were oblique or spiral, and 2 were vertical split fractures. Thirty-two (61.5%) fractures were open and 20 were closed. Twenty-one (40.4%) had concomitant significant soft tissue injuries . There were 16 extensor tendon and 6 flexor tendon injuries. Five digital nerves were severed. Seven digits had extensive skin loss. Ten fractures were fixed with 1.5 mm or 2 mm screws. Thirty-three were treated with miniature plates (Fig. 2, A and B). The remaining nine periarticular fractures were fixed with minicondylar plates (Fig. I). The overall results are shown in (Table I). Using the chi-square method, there is no significant difference in the results between proximal and middle phalangeal fractures. The results of the fractures treated by plating or screw fixation alone are shown in Table II. The latter group of fractures showed slightly better results although the
difference is not statistically significant as assessed by the chi-square test. Comparison of the results was made between fractures with or without significant soft tissue injuries using the chi-square test (Table III). Fractures without significant soft tissue injuries have significantly better results (p = 0.009). There were nine complications related to either the technique of fixation or the implant itself. Penetration of the joint cavity by the blade of the minicondylar 'plate occurred in two digits . In two out of three fractures treated by plating, the plates were relatively large and wound dehiscence with exposure of the plate occurred . A broken plate was encountered in one patient before fracture healing. In another, dislodgement of the screw from the plate occurred. Inadequate fixation with loss of reduction was noticed in two fractures treated by screw fixation alone, this was probably the result of inappropriate selection of the implant. In retrospect, plate fixation should have been used in these two fractures. In addition to the above complications, unsatisfactory reduction was noticed in four digits because of the severe comminution. There were four nonunions and two infections . The two cases of infection were not associated with extensive skin loss. Six patients required
116
PIlII
The Journal of HAND SURGERY
et al,
Table IV. Results of fractures* fixed by two different techniques Good
Kirschner wire fixation
A.a. fixation
4t% 35.7%
I
Fair
Poor
Total
20.5% 39.3%
38.5% 25%
39 28
'Multiple fractures in the same hand and fractures associated with "significant soft tissue injuries" were excluded.
tenolysis or capsulotomy after the fracture had healed to improve the active motion of their digits. Finally, we compared the results of the present series with a previously reported group of comparable middle and proximal phalangeal fracture;': S which had been fixed by Kirschner wires (Table IV). The latter group of fractures had the same indications for open reduction and internal fixation as the present series. To draw a more significant conclusion, we minimized the number of factors in the two groups of fractures and made them more homogeneous. Multiple fractures in the saine hand and fractures associated with "significant soft tissue injuries" were excluded from the comparison because they were found to be poor prognostic factors from our previous prospective study.' The results of the present series were no better than those fixed by Kirschner wires. In fact, there is no significant difference in the results as assessed by the chi-square test.
Discussion This study is unique in that it is prospective and only unstable fractures are included in the study. In the literature, several studies"? have shown that the results of unstable metacarpal fractures fixed with A.a. screws and plates are satisfactory and this is also our experience. Therefore, we limited our study to the unstable phalangeal fractures, which are very challenging, difficult to manage and in which the results of Kirschner wire fixation are not satisfactory. In this study, the results of A.a. miniature plate and screw fixation for the same group of fractures are again not encouraging and complications are very frequent despite the operations being carefully done by experienced surgeons. In fact, there is no significant improvement in the results when the present technique of internal fixation is compared with Kirschner wire fixation (Table IV). There are several drawbacks in the design of the A.a. miniature plates and screws. The plates are sometimes too large compared to the small phalangeal bones, especially middle phalanges or phalanges in the small finger. The prominence of the head end of the condylar plate often causes impingement on the skin and the
contour of the plate itself does not always fit all phalanges well, consequently precise moulding with benders is required. The hexagonal screw head is bulky and interferes at the proximal phalanx with the gliding of the extensor tendon and the oblique bands. The present technique of fixation often requires more soft tissue dissection compared to Kirschner wire fixation and therefore increases the soft tissue trauma. Overall, the present technique of internal fixation is very demanding and permits no latitude. All these problems seem to outweigh the theoretical advantage of more rigid fixation provided by the A.a. plate and screw and frequently lead to complications. Similar experience had also been reported by Stem and colleagues." It is possible that the outcome of this group of unstable fractures is predetermined because to begin with they are complicated fractures and have frequent association with poor prognostic factors. In our previous prospective study,' "open fractures," "comminuted fractures," and "associated significant soft tissue injuries" all contributed to a poor prognosis. In the present group of unstable fractures, 61.5% were open; 40.4% had significant soft tissue injuries, and 36.5% were comminuted. It appears that the presence of these poor prognostic factors is more important than the method of fixation in determining the final results. 10. \I In fact, the results in Tables III and IV show the importance of the poor prognostic factors in determining the final results of the fractures. This may explain the marked difference in the results between the series of Dabezies and Schutte? and ours because comminuted fractures and fractures associated with significant soft tissue injuries were not included in the former series. REFERENCES I. James lIP. Fractures of the proximal and middle phalanges of the fingers. Acta Orthop Scand 1962;32:40112. 2. Green DP, Anderson JR. Closed reduction and percutaneous pin fixation of fractured phalanges. J Bone Joint Surg 1973;55A:1651-4. 3. Pun WK, Chow SP, So YC, et aI. A prospective study on 284 digital fractures of the hand. J HAND SURG 1989;14A:474-81. 4. Massengill ra, Alexander H, Langrana N, Mylod A. A phalangeal fracture model-quantitative analysis of rigidity and failure. J HAND SURG 1982;7A:264-70. 5. Buchler U, Fischer T. Use of a minicondylar plate for metacarpal and phalangeal periarticular injuries. Clin Orthop 1987;214:53-8. 6. Gingrass RP, Fehring BHT, Matloub H. Intraosseous wiring of complex hand fractures. Plast Reconstr Surg 1980;66:383-9(
Vol. 16A, No. I January 1991
7. Stern PJ, Wieser MJ, Reilly DO. Complications of plate fixation in the hand skeleton. Clin Orthop 1987;214:5965. 8. Ford OJ, El-Hadidi S, Lunn PO, Burke FD. Fractures of the metacarpals: Treatment by A.O. screw and plate fixation. J HAND SURG 1987;12B:34-7. 9. Dabczies EJ, Schutte JP. Fixation of metacarpal and phalangeal fractures with miniature plates and screws. J HAND SURG 1986;IIA:283-8.
Unstable phalangeal fractures
10. Hastings H. Unstable metacarpal and phalangeal fracture treatment with screws and plates. Clin Orthop 1987; 214:37-52. II. Huffaker WH, Wray RC, Weeks PM. Factors influencing final range of motion in the fingers after fractures of the hand. Plast Reconstr Surg 1979;63:82-7.
Rotating shaft avulsion amputations of the thumb In a three-year period twenty-nine patients were treated for rotating shaft avulsion amputations of the thumb. Twenty-three thumbs were considered suitable for replantation. A staged approach, consisting of primary replantation and secondary nerve grafting and tendon reconstruction, was used because of concern that survival rates would be low. Survival was achieved in nineteen of twenty-three replantations. At mean follow-up of 20.5 months grip strength was 94.6% of the unaffected side and key pinch was 77.1 '70. Five patients achieved a two-point discrimination less than five millimeters. Success was better anticipated and now a full reconstruction is carried out in a single-stage procedure. (J HAND SURG 1991jI6A:1l7-21.)
C. V. A. Bowen, MB, ChB, FRCSC, Toronto, Ont., J. Beveridge, MD, FRCSC, R. G. Milliken, MD, CM, FRCSC, and G. H. F. Johnston, MD, FRCSC, Saskatoon, Saskatchewan, Canada
In western Canada, traumatic amputations of the thumb are common. They almost invariably result from entanglement with the rotating shaft of agricultural power take-off" 2 couplings, when farmers are using their tractors to drive motorized machinery." Functionally, the injuries are potentially devastating since the thumb contributes so much to total hand function. The best form of reconstruction is replantation, but the literature has indicated that for these avulsion type From the Department of Orthopaedic Surgery, University Hospital, Saskatoon. Saskatchewan, Canada, Received for pubtication June 27. 1989; accepted in revised form Dee, 4, 1989, Although none of the authors have received or will receive benefits for personal or professionat use from a commercial party related directly or indirectly to the subject of this article. benefits have been or will be received but are directly solely to a research fund, foundation, educational institution, or other non-profit organization with which one or more of the authors are associated. Reprint requests: Dr. Vaughan Bowen, EN 10-243 Toronto General Hospital, 200 Elizabeth St. Toronto, Ont., Canada, M5G 2C4. 3/1120582
of amputations high survival rates might not be achieved. For this reason, in our hospital, avulsion amputations of the thumb have been managed with a twostaged reconstruction. The first stage aimed at achieving microvascular survival and the second stage was done for functional reconstruction of nerves and tendons. This article reviews the results of this management technique. Materials and methods A study was made of all patients with rotating shaft avulsion amputations of the thumb that were managed at the Univerity Hospital in Saskatoon over a 3-year period between January 1984 and February 1987. Hospital charts and radiologic files were reviewed and the following factors were analyzed: Data concerning patients and accidents, types of injury sustained, clinical management, and final outcome. Patients were then recalled and reviewed clinically. At follow-up patients were asked about pain, cold intolerance, and their ability to use the replanted digits. Thumbs were assessed for appearance, movement, strength and sensibility. TIlE JOURNAL OF HAND SURGERY
117
