Eur J Trauma Emerg Surg (2013) 39:159–162 DOI 10.1007/s00068-012-0245-3
ORIGINAL ARTICLE
Locking Compression Plates are more difficult to remove than conventional non-locking plates G. D. Musters • P. Boele van Hensbroek • K. J. Ponsen • J. S. K. Luitse • J. C. Goslings
Received: 3 October 2012 / Accepted: 17 December 2012 / Published online: 11 January 2013 Ó Springer-Verlag Berlin Heidelberg 2013
Abstract Purpose Locking Compression Plates (LCPs) have been introduced in the last decade. Clinicians have the impression that hardware removal of LCPs are more difficult and associated with more complications than conventional (non-locking) plates. Therefore, this study compares the complication rates of Locking Compression Plate (LCP) removal and conventional non-locking plate removal. Patients and methods Patients who underwent open reduction and internal fixation and subsequent hardware removal at the Department of Trauma Surgery at our Level 1 Trauma Centre between 1993 and 2007 were included through the hospital’s information system. The primary outcome measure was the occurrence of complications during implant removal. Results A total of 210 patients were included. The females were significantly older than the males [median age, 51.5 vs. 42.6 years (p \ 0.001)]. The median operation time of LCP removal was significantly longer than the operation time of non-locking plate removal (72 vs. 54 min, p \ 0.001). In the total study population, complications during implant removal occurred in 25 patients (11.9%). The complication rate of conventional non-locking plate removal was 2.5%. The complication rate of LCP removal was significantly higher (17.7%, p = 0.001).
G. D. Musters (&) P. Boele van Hensbroek K. J. Ponsen J. S. K. Luitse J. C. Goslings Academic Medical Centre, Department of Trauma Surgery, University of Amsterdam, G4, Post box 22660, 1105 AZ Amsterdam, The Netherlands e-mail: [email protected] J. C. Goslings e-mail: [email protected]
Conclusion LCP removal is associated with significantly more complications than conventional non-locking plate removal. The indication for removal of locking compression should be made cautiously, and surgical instruments for LCP removal should be optimized. Keywords Locking compression plates LCP Complications Hardware removal Conventional plates
Introduction The removal of internal fracture fixation devices are frequently considered a simple procedure for a resident, a presumption that is not always borne out in practice. Fracture fixation was previously achieved using conventional (non-locking) plates and screws. These were tightly driven into the bone to achieve a stable construction. With the Locking Compression Plate (LCP), introduced at our university hospital in February 2002, the screw head ‘‘locks’’ into the plate, creating a stable construction without necessarily fully tightening the plate to the bone [10]. At our hospital, we had the impression that we experienced more difficulties with the removal of LCP compared with conventional non-locking plates. Many of these difficulties were associated with the screws. Current literature on this subject is limited and does not support or refute this impression. This study was designed to compare the complication rate of conventional non-locking plate removal with the complication rate of LCP removal. Our hypothesis, derived from daily clinical practice, was that the complication rate of LCP removal would be significantly higher compared to conventional non-locking plate removal.
123
160
Patients and methods The records of all patients who underwent open reduction and internal fixation followed by hardware removal at our Level 1 Trauma Centre between 1 April 1993 and 31 December 2007 were retrieved from the hospital’s information system. Only those patients who had their implants placed as well as removed at our hospital were included. The time interval for inclusion was chosen because it covers at least five years before the introduction of the LCP (2002) and at least five years since the introduction of the LCPs. Implantation and removal of the non-locking plates were performed during the selected time frame of inclusion. The included patients were divided into a cohort with conventional non-locking plates and a cohort with LCPs. All operations were performed or supervised by staff trauma surgeons. Various titanium LCP types (Synthes, West Chester, PA, USA) and various screw types were used for fracture fixation. The LCPs consisted of (predominantly) hexagonal and star drive screw heads. The non-locking plating consisted of variable sized stainless steel plates and screws. Almost all screws were tightened with a torque-limited screwdriver as instructed by the supplier. Indications for implant removal were categorized into five groups: pain or other complaints, a broken screw or plate, fracture complications, infection, or not otherwise specified. Whenever possible, LCPs were removed using the least invasive technique: a small incision was made, tissue in the screw head was removed, and the screw was loosened with a hand screwdriver. If no grip was obtained, a counter tap screw was used in the second attempt to unscrew the screws. If the counter tap screw failed to unscrew the screws, a special hardened steel drill was used to remove the screw head. The primary outcome measure was the occurrence of complications during the removal of the conventional nonlocking plates (stainless steel) and LCPs (titanium). Complications were defined as any difficulties with implant removal occurring during the procedure and mentioned in the operation report. Secondary outcome measures were age, sex, location of the implant, indications for removal, type of fracture and classification of the difficulties encountered in removal. The fractures were categorized according to the AO-classification (type A–C). In addition, a pair-wise comparison was performed between the three groups by Chi-square test or Fisher’s exact test. Statistical analysis Statistical significance was assessed using Chi-square, Fisher’s exact, and Mann–Whitney U tests as appropriate. Correlations were assessed using the Pearson and Spearman correlations as appropriate. Differences were
123
G. D. Musters et al.
considered to be significant if the p value was less than 0.05. The data were analyzed using statistical analyses in SPSS version 18.0.1. (SPSS, Chicago, IL, USA).
Results Patients’ characteristics A total of 210 patients were included. The mean age at the time of implant removal was 46.7 years (range 15.1–91.1) and there were 114 (54.3%) male patients. Female patients were significantly older than males [median age: 51.5 vs. 42.6 years (p \ 0.001)]. LCPs were used in 130 patients (61.9%) and 80 non-locking plates were used. The type of fracture and the type of implant is shown in Table 1. There was no statistical significant difference in the use of conventional plates or LCPs used in the A type fractures. Furthermore, no statistical significance was found in the use of conventional plates or LCPs in the B type fractures. Only for the C-type fractures were significantly more LCPs used in comparison to the conventional plates (p \ 0.05). Implant removal The implants were removed after a median period of 10.9 (LCP) and 14.1 months (non-LCP; p \ 0.05). The indications for implant removal are shown in Table 2. Broken plates and fracture-related complications were indications that occurred significantly more often for LCP removal. The median operation time of LCP removal was significantly longer than the operation time of non-locking plate removal (72 vs. 54 min, p \ 0.001). Complications In the total study population, complications during implant removal occurred in 25 patients (11.9%). The complication rate of conventional non-locking plate removal was 2.5 % (2/80), vs. 7.7% (23/130) for LCP removal (p = 0.001). The overall complication rate for upper extremities was 14.9% (11/74) vs. 10.3% (14/136) in the lower extremities. Table 1 Type of fracture for which a plate was used AO-Classification
Total (n)
Non-locking % (n)
LCP % (n)
Type A
48
35 (17)
65 (31)
Type B
80
39 (31)
61 (49)
Type Ca
61
21 (13)
79 (48)
Unknown
21
90 (19)
10 (2)
80
130
Total a
210
Significantly more C type fractures in the locking compression plate group compared to the non-locking plate group
Locking Compression Plates are more difficult to remove than conventional non-locking plates Table 2 Indications for plate removal Operation indications
Non-locking (n)
Pain or other complaints
LCP (n)
Value (p)
30
39
0.412
Broken plate
0
10
0.013
Fracture complications
0
7
0.044 0.279
Infection
6
14
Not otherwise specified
47
57
-
Total
83
127
-
n number of patients, LCP Locking Compression Plate, Chi-square test
In the upper extremities, the complication rate of conventional non-locking plates was 8.7% (2/23) vs. 17.6% (9/51) for LCPs. In the lower extremities, the complication rate of conventional non-locking plates was 0% (0/57) vs. 17.7% (14/79) for LCPs (p \ 0.005). The complications of the conventional implant and LCPs in the different anatomic regions are shown in Table 3. The types of complication during LCP removal were screw breakage during removal (n = 9), slipping of the screwdriver in the screw head (n = 8), and screws that could not be mobilized (n = 6). The type of complication in the removal of conventional non-locking plates was screw breakage (n = 2). The problems with the screws that were damaged or could not be mobilized were resolved by drilling out the screw in 18 patients. In three patients a counter-tapped screw was used to resolve the problem. In the remaining patients, combinations of these techniques were used.
Discussion Our study shows a significantly higher complication rate for removal of LCPs compared to the removal of conventional non-locking plates. In comparison to a recent report, this report had a much higher overall complication rate of LCP removal [1]. One of the possible explanations is that our report presents the complications per operation and not per individual screw. In addition, the operation time was significantly longer when LCPs were removed. This can also have logistical implications. When an operation takes longer than planned, it might cause following operations to be delayed or even postponed. In this report, all of the conventional non-locking plates were made of stainless steel and all LCPs were made of titanium. Due to the easier deformability of titanium, a cold weld or cross-threading can more easily occur in titanium than in stainless steel, although this mechanism is questioned [8]. Therefore, more torque is required in the removal of the titanium screws in comparison to the stainless steel screws [3]. Vresilovic et al. [9] also reported
161
more complications in the removal of titanium screws in comparison to stainless steel screws. In addition, there may be biomechanical differences between stainless steel and titanium in terms of fatigue stress that contribute to the difference in complications. Several problems with implant removal are related to the instruments used during insertion and removal. First, the force applied through the screwdriver may be a factor. Tightening a locking screw into an LCP with excess force may create a cold weld or cross-threading between the screw and plate [2, 8]. The use of torque-controlling screwdrivers has been offered by some authors as an important factor to prevent cold weld between the screw head and the screw hole [2, 4, 7]. Furthermore, a properly introduced targeting device is also a factor in preventing cross-threading of the screw head into the screw hole [2]. Secondly, worn screwdrivers may lead to decreased contact surface for solid engagement, allowing for easier deformation of the screw head [1, 2, 4]. This problem occurs more frequently with titanium LCPs than with stainless steel non-locking plates [2]. This suggests that the harder stainless steel screws may be less susceptible to damage from worn screwdrivers. However, the effect of worn screwdrivers may be difficult to measure. When the hexagonal head of the screw is damaged, it may be impossible to determine if this occurred during placement or removal. Although this remains a matter of speculation, it is advisable for the operating surgeon to check the state of the screwdriver tip before attempting to place or remove a screw. When problems were encountered during implant removal at our hospital, the least invasive removal technique was used first. Most often, a counter tap screw was used in the first attempt to unscrew the screws. In resolving the problem of screws that could not be mobilized, most were resolved by drilling out the screw. Some additional techniques have been described in the literature. One article suggested the foil wrap method, in which the foil is placed between the recesses of the screw and the tip of the screwdriver when the screw is attempted to be unscrewed [6]. Another article described a technique in which the plate was bent around the stripped screw, resulting in a loosening of the interaction between plate and screw [2]. If more than one screw is involved, the plate can be cut through the dynamic compression unit of the combination hole by using a metal cutting saw [1]. The screw heads can also be drilled out using a carbide or diamond-tipped drill [8]. This study has several limitations. Firstly, it is a retrospective review of data. Secondly, the operation reports were not structured, which may have resulted in the omission of data. It cannot be determined retrospectively whether no problems occurred or problems were simply not reported during implant removal. Thirdly, all LCPs and
123
162
G. D. Musters et al.
Table 3 Conventional non-locking plates and LCPs and their complications in the different anatomic regions Location of the hardware
Total (n)
Non-locking (n)
Non-locking complications (n)
LCP (n)
LCP complications (n)
Upper extremity Humerus proximal
2
2
0
0
0
Humerus shaft
5
1
0
4
1
Humerus distal
5
1
0
4
2
Radius proximal
3
0
0
3
0
Radius shaft
6
2
0
4
2
Radius distal
24
7
1
17
0
Ulna proximal
14
2
1
12
2
Ulna shaft
9
5
0
4
1
Ulna distal
3
3
0
0
0
Forearm shafta Forearm distala
2 1
0 0
0 0
2 1
0 1
14
7
0
7
1
Femur shaft
9
1
0
8
3
Distal femur
8
2
0
6
0
Proximal tibia
12
2
0
10
1
Tibia shaft
14
5
0
9
1
Tibia pilon
15
1
0
14
1
Ankle/foot
64
39
0
25
7
Lower extremity Proximal femur
n number of patients, LCP Locking Compression Plate a
Both the radius and ulna were fractured and the implants were removed during the same operation
conventional non-locking plates in this study were from one single manufacturer, and these results do not apply to other brands. Fourthly, the mean age of our female patients was significantly higher. This can be related to the fact that males are more likely to sustain a fracture at a younger age and females more likely to sustain a fracture at a postmenopausal age (i.e., due to osteoporosis) [5]. Finally, the fractures for which an LCP was used were more complicated than for the fractures for which a non-locking plate was used. The difference in severity of the fracture was small, but it may have complicated the removal of the LCPs.
Conclusion Based on this study, the authors conclude that LCP removal is associated with significantly more complications than conventional non-locking plate removal. Therefore, indications for removal of locking compression should be made cautiously. We recommend the use of a torquecontrolling screwdriver when applying LCPs; instruments for LCP removal should be optimized. Conflict of interest
123
None.
References 1. Bae JH, Oh JK, Oh CW, et al. Technical difficulties of removal of locking screw after locking compression plating. Arch Orthop Trauma Surg. 2009;129:91–5. 2. Ehlinger M, Adam P, Simon P, et al. Technical difficulties in hardware removal in titanium compression plates with locking screws. Orthop Traumatol Surg Res. 2009;95:373–6. 3. Eulenberger J, Steinemann SG. Removal torques of small screws of steel and titanium with different surfaces. Unfallchirurg. 1990;93:96–9. 4. Georgiadis GM, Gove NK, Smith AD, et al. Removal of the less invasive stabilization system. J Orthop Trauma. 2004;18:562–4. 5. Geusens P, Dinant G. Integrating a gender dimension into osteoporosis and fracture risk research. Gend Med. 2007;4(Suppl B):S147–61. 6. Pattison G, Reynolds J, Hardy J. Salvaging a stripped drive connection when removing screws. Injury. 1999;30:74–5. 7. Phisitkul P, McKinley TO, Nepola JV, et al. Complications of locking plate fixation in complex proximal tibia injuries. J Orthop Trauma. 2007;21:83–91. 8. Suzuki T, Smith WR, Stahel PF, et al. Technical problems and complications in the removal of the less invasive stabilization system. J Orthop Trauma. 2010;24:369–73. 9. Vresilovic EJ, Spindler KP, Robertson WW Jr, et al. Failures of pin removal after in situ pinning of slipped capital femoral epiphyses: a comparison of different pin types. J Pediatr Orthop. 1990;10:764–8. 10. Wagner M. General principles for the clinical use of the LCP. Injury. 2003;34:31–42.
ORIGINAL ARTICLE
Locking Compression Plates are more difficult to remove than conventional non-locking plates G. D. Musters • P. Boele van Hensbroek • K. J. Ponsen • J. S. K. Luitse • J. C. Goslings
Received: 3 October 2012 / Accepted: 17 December 2012 / Published online: 11 January 2013 Ó Springer-Verlag Berlin Heidelberg 2013
Abstract Purpose Locking Compression Plates (LCPs) have been introduced in the last decade. Clinicians have the impression that hardware removal of LCPs are more difficult and associated with more complications than conventional (non-locking) plates. Therefore, this study compares the complication rates of Locking Compression Plate (LCP) removal and conventional non-locking plate removal. Patients and methods Patients who underwent open reduction and internal fixation and subsequent hardware removal at the Department of Trauma Surgery at our Level 1 Trauma Centre between 1993 and 2007 were included through the hospital’s information system. The primary outcome measure was the occurrence of complications during implant removal. Results A total of 210 patients were included. The females were significantly older than the males [median age, 51.5 vs. 42.6 years (p \ 0.001)]. The median operation time of LCP removal was significantly longer than the operation time of non-locking plate removal (72 vs. 54 min, p \ 0.001). In the total study population, complications during implant removal occurred in 25 patients (11.9%). The complication rate of conventional non-locking plate removal was 2.5%. The complication rate of LCP removal was significantly higher (17.7%, p = 0.001).
G. D. Musters (&) P. Boele van Hensbroek K. J. Ponsen J. S. K. Luitse J. C. Goslings Academic Medical Centre, Department of Trauma Surgery, University of Amsterdam, G4, Post box 22660, 1105 AZ Amsterdam, The Netherlands e-mail: [email protected] J. C. Goslings e-mail: [email protected]
Conclusion LCP removal is associated with significantly more complications than conventional non-locking plate removal. The indication for removal of locking compression should be made cautiously, and surgical instruments for LCP removal should be optimized. Keywords Locking compression plates LCP Complications Hardware removal Conventional plates
Introduction The removal of internal fracture fixation devices are frequently considered a simple procedure for a resident, a presumption that is not always borne out in practice. Fracture fixation was previously achieved using conventional (non-locking) plates and screws. These were tightly driven into the bone to achieve a stable construction. With the Locking Compression Plate (LCP), introduced at our university hospital in February 2002, the screw head ‘‘locks’’ into the plate, creating a stable construction without necessarily fully tightening the plate to the bone [10]. At our hospital, we had the impression that we experienced more difficulties with the removal of LCP compared with conventional non-locking plates. Many of these difficulties were associated with the screws. Current literature on this subject is limited and does not support or refute this impression. This study was designed to compare the complication rate of conventional non-locking plate removal with the complication rate of LCP removal. Our hypothesis, derived from daily clinical practice, was that the complication rate of LCP removal would be significantly higher compared to conventional non-locking plate removal.
123
160
Patients and methods The records of all patients who underwent open reduction and internal fixation followed by hardware removal at our Level 1 Trauma Centre between 1 April 1993 and 31 December 2007 were retrieved from the hospital’s information system. Only those patients who had their implants placed as well as removed at our hospital were included. The time interval for inclusion was chosen because it covers at least five years before the introduction of the LCP (2002) and at least five years since the introduction of the LCPs. Implantation and removal of the non-locking plates were performed during the selected time frame of inclusion. The included patients were divided into a cohort with conventional non-locking plates and a cohort with LCPs. All operations were performed or supervised by staff trauma surgeons. Various titanium LCP types (Synthes, West Chester, PA, USA) and various screw types were used for fracture fixation. The LCPs consisted of (predominantly) hexagonal and star drive screw heads. The non-locking plating consisted of variable sized stainless steel plates and screws. Almost all screws were tightened with a torque-limited screwdriver as instructed by the supplier. Indications for implant removal were categorized into five groups: pain or other complaints, a broken screw or plate, fracture complications, infection, or not otherwise specified. Whenever possible, LCPs were removed using the least invasive technique: a small incision was made, tissue in the screw head was removed, and the screw was loosened with a hand screwdriver. If no grip was obtained, a counter tap screw was used in the second attempt to unscrew the screws. If the counter tap screw failed to unscrew the screws, a special hardened steel drill was used to remove the screw head. The primary outcome measure was the occurrence of complications during the removal of the conventional nonlocking plates (stainless steel) and LCPs (titanium). Complications were defined as any difficulties with implant removal occurring during the procedure and mentioned in the operation report. Secondary outcome measures were age, sex, location of the implant, indications for removal, type of fracture and classification of the difficulties encountered in removal. The fractures were categorized according to the AO-classification (type A–C). In addition, a pair-wise comparison was performed between the three groups by Chi-square test or Fisher’s exact test. Statistical analysis Statistical significance was assessed using Chi-square, Fisher’s exact, and Mann–Whitney U tests as appropriate. Correlations were assessed using the Pearson and Spearman correlations as appropriate. Differences were
123
G. D. Musters et al.
considered to be significant if the p value was less than 0.05. The data were analyzed using statistical analyses in SPSS version 18.0.1. (SPSS, Chicago, IL, USA).
Results Patients’ characteristics A total of 210 patients were included. The mean age at the time of implant removal was 46.7 years (range 15.1–91.1) and there were 114 (54.3%) male patients. Female patients were significantly older than males [median age: 51.5 vs. 42.6 years (p \ 0.001)]. LCPs were used in 130 patients (61.9%) and 80 non-locking plates were used. The type of fracture and the type of implant is shown in Table 1. There was no statistical significant difference in the use of conventional plates or LCPs used in the A type fractures. Furthermore, no statistical significance was found in the use of conventional plates or LCPs in the B type fractures. Only for the C-type fractures were significantly more LCPs used in comparison to the conventional plates (p \ 0.05). Implant removal The implants were removed after a median period of 10.9 (LCP) and 14.1 months (non-LCP; p \ 0.05). The indications for implant removal are shown in Table 2. Broken plates and fracture-related complications were indications that occurred significantly more often for LCP removal. The median operation time of LCP removal was significantly longer than the operation time of non-locking plate removal (72 vs. 54 min, p \ 0.001). Complications In the total study population, complications during implant removal occurred in 25 patients (11.9%). The complication rate of conventional non-locking plate removal was 2.5 % (2/80), vs. 7.7% (23/130) for LCP removal (p = 0.001). The overall complication rate for upper extremities was 14.9% (11/74) vs. 10.3% (14/136) in the lower extremities. Table 1 Type of fracture for which a plate was used AO-Classification
Total (n)
Non-locking % (n)
LCP % (n)
Type A
48
35 (17)
65 (31)
Type B
80
39 (31)
61 (49)
Type Ca
61
21 (13)
79 (48)
Unknown
21
90 (19)
10 (2)
80
130
Total a
210
Significantly more C type fractures in the locking compression plate group compared to the non-locking plate group
Locking Compression Plates are more difficult to remove than conventional non-locking plates Table 2 Indications for plate removal Operation indications
Non-locking (n)
Pain or other complaints
LCP (n)
Value (p)
30
39
0.412
Broken plate
0
10
0.013
Fracture complications
0
7
0.044 0.279
Infection
6
14
Not otherwise specified
47
57
-
Total
83
127
-
n number of patients, LCP Locking Compression Plate, Chi-square test
In the upper extremities, the complication rate of conventional non-locking plates was 8.7% (2/23) vs. 17.6% (9/51) for LCPs. In the lower extremities, the complication rate of conventional non-locking plates was 0% (0/57) vs. 17.7% (14/79) for LCPs (p \ 0.005). The complications of the conventional implant and LCPs in the different anatomic regions are shown in Table 3. The types of complication during LCP removal were screw breakage during removal (n = 9), slipping of the screwdriver in the screw head (n = 8), and screws that could not be mobilized (n = 6). The type of complication in the removal of conventional non-locking plates was screw breakage (n = 2). The problems with the screws that were damaged or could not be mobilized were resolved by drilling out the screw in 18 patients. In three patients a counter-tapped screw was used to resolve the problem. In the remaining patients, combinations of these techniques were used.
Discussion Our study shows a significantly higher complication rate for removal of LCPs compared to the removal of conventional non-locking plates. In comparison to a recent report, this report had a much higher overall complication rate of LCP removal [1]. One of the possible explanations is that our report presents the complications per operation and not per individual screw. In addition, the operation time was significantly longer when LCPs were removed. This can also have logistical implications. When an operation takes longer than planned, it might cause following operations to be delayed or even postponed. In this report, all of the conventional non-locking plates were made of stainless steel and all LCPs were made of titanium. Due to the easier deformability of titanium, a cold weld or cross-threading can more easily occur in titanium than in stainless steel, although this mechanism is questioned [8]. Therefore, more torque is required in the removal of the titanium screws in comparison to the stainless steel screws [3]. Vresilovic et al. [9] also reported
161
more complications in the removal of titanium screws in comparison to stainless steel screws. In addition, there may be biomechanical differences between stainless steel and titanium in terms of fatigue stress that contribute to the difference in complications. Several problems with implant removal are related to the instruments used during insertion and removal. First, the force applied through the screwdriver may be a factor. Tightening a locking screw into an LCP with excess force may create a cold weld or cross-threading between the screw and plate [2, 8]. The use of torque-controlling screwdrivers has been offered by some authors as an important factor to prevent cold weld between the screw head and the screw hole [2, 4, 7]. Furthermore, a properly introduced targeting device is also a factor in preventing cross-threading of the screw head into the screw hole [2]. Secondly, worn screwdrivers may lead to decreased contact surface for solid engagement, allowing for easier deformation of the screw head [1, 2, 4]. This problem occurs more frequently with titanium LCPs than with stainless steel non-locking plates [2]. This suggests that the harder stainless steel screws may be less susceptible to damage from worn screwdrivers. However, the effect of worn screwdrivers may be difficult to measure. When the hexagonal head of the screw is damaged, it may be impossible to determine if this occurred during placement or removal. Although this remains a matter of speculation, it is advisable for the operating surgeon to check the state of the screwdriver tip before attempting to place or remove a screw. When problems were encountered during implant removal at our hospital, the least invasive removal technique was used first. Most often, a counter tap screw was used in the first attempt to unscrew the screws. In resolving the problem of screws that could not be mobilized, most were resolved by drilling out the screw. Some additional techniques have been described in the literature. One article suggested the foil wrap method, in which the foil is placed between the recesses of the screw and the tip of the screwdriver when the screw is attempted to be unscrewed [6]. Another article described a technique in which the plate was bent around the stripped screw, resulting in a loosening of the interaction between plate and screw [2]. If more than one screw is involved, the plate can be cut through the dynamic compression unit of the combination hole by using a metal cutting saw [1]. The screw heads can also be drilled out using a carbide or diamond-tipped drill [8]. This study has several limitations. Firstly, it is a retrospective review of data. Secondly, the operation reports were not structured, which may have resulted in the omission of data. It cannot be determined retrospectively whether no problems occurred or problems were simply not reported during implant removal. Thirdly, all LCPs and
123
162
G. D. Musters et al.
Table 3 Conventional non-locking plates and LCPs and their complications in the different anatomic regions Location of the hardware
Total (n)
Non-locking (n)
Non-locking complications (n)
LCP (n)
LCP complications (n)
Upper extremity Humerus proximal
2
2
0
0
0
Humerus shaft
5
1
0
4
1
Humerus distal
5
1
0
4
2
Radius proximal
3
0
0
3
0
Radius shaft
6
2
0
4
2
Radius distal
24
7
1
17
0
Ulna proximal
14
2
1
12
2
Ulna shaft
9
5
0
4
1
Ulna distal
3
3
0
0
0
Forearm shafta Forearm distala
2 1
0 0
0 0
2 1
0 1
14
7
0
7
1
Femur shaft
9
1
0
8
3
Distal femur
8
2
0
6
0
Proximal tibia
12
2
0
10
1
Tibia shaft
14
5
0
9
1
Tibia pilon
15
1
0
14
1
Ankle/foot
64
39
0
25
7
Lower extremity Proximal femur
n number of patients, LCP Locking Compression Plate a
Both the radius and ulna were fractured and the implants were removed during the same operation
conventional non-locking plates in this study were from one single manufacturer, and these results do not apply to other brands. Fourthly, the mean age of our female patients was significantly higher. This can be related to the fact that males are more likely to sustain a fracture at a younger age and females more likely to sustain a fracture at a postmenopausal age (i.e., due to osteoporosis) [5]. Finally, the fractures for which an LCP was used were more complicated than for the fractures for which a non-locking plate was used. The difference in severity of the fracture was small, but it may have complicated the removal of the LCPs.
Conclusion Based on this study, the authors conclude that LCP removal is associated with significantly more complications than conventional non-locking plate removal. Therefore, indications for removal of locking compression should be made cautiously. We recommend the use of a torquecontrolling screwdriver when applying LCPs; instruments for LCP removal should be optimized. Conflict of interest
123
None.
References 1. Bae JH, Oh JK, Oh CW, et al. Technical difficulties of removal of locking screw after locking compression plating. Arch Orthop Trauma Surg. 2009;129:91–5. 2. Ehlinger M, Adam P, Simon P, et al. Technical difficulties in hardware removal in titanium compression plates with locking screws. Orthop Traumatol Surg Res. 2009;95:373–6. 3. Eulenberger J, Steinemann SG. Removal torques of small screws of steel and titanium with different surfaces. Unfallchirurg. 1990;93:96–9. 4. Georgiadis GM, Gove NK, Smith AD, et al. Removal of the less invasive stabilization system. J Orthop Trauma. 2004;18:562–4. 5. Geusens P, Dinant G. Integrating a gender dimension into osteoporosis and fracture risk research. Gend Med. 2007;4(Suppl B):S147–61. 6. Pattison G, Reynolds J, Hardy J. Salvaging a stripped drive connection when removing screws. Injury. 1999;30:74–5. 7. Phisitkul P, McKinley TO, Nepola JV, et al. Complications of locking plate fixation in complex proximal tibia injuries. J Orthop Trauma. 2007;21:83–91. 8. Suzuki T, Smith WR, Stahel PF, et al. Technical problems and complications in the removal of the less invasive stabilization system. J Orthop Trauma. 2010;24:369–73. 9. Vresilovic EJ, Spindler KP, Robertson WW Jr, et al. Failures of pin removal after in situ pinning of slipped capital femoral epiphyses: a comparison of different pin types. J Pediatr Orthop. 1990;10:764–8. 10. Wagner M. General principles for the clinical use of the LCP. Injury. 2003;34:31–42.
