Journal of Orthopaedic Surgery 2014;22(3):347-50
Fixation strength at the interface between Kerboull-type plate and bone cement Nobuhiro Kaku, Katsutoshi Hara, Tomonori Tabata, Hiroshi Tsumura
Department of Orthopaedic Surgery, Faculty of Medicine, Oita University, Oita, Japan.
ABSTRACT Purpose. To evaluate the fixation strength at the interface between the Kerboull-type plate and bone cement in 6 experimental conditions. Methods. Experimental materials comprised a simulated acetabular block, a simulated Kerboulltype plate, a pressuriser cover, a pressuriser arm, and bone cement. The simulated Kerboull-type plate was placed on the simulated acetabular block, with the pressuriser cover. Bone cement was added and the pressuriser arm was inserted. After 6 days of curing, pulling tests were performed to measure the fixation strength at the interface between the plate and the bone cement. Six experimental conditions were evaluated. In condition 1, a 1-mm plate was used with no gap between the plate and the acetabular block. In condition 2, a 2.5-mm plate was used with no gap. In condition 3, a 2.5-mm plate was used with a 2-mm gap. In condition 4, the plate was not used. In condition 5, condition 2 was tested with the model rotated 45º. In condition 6, condition 3 was tested
with the model rotated 45º. Results. The maximum fixation strengths in conditions 1, 2, 3, 5, and 6 were 44.4 N, 59.1 N, 122.5 N, 86.9 N, and 185.2 N, respectively. The most important factor affecting the maximum fixation strength was bone cement at the interface between the plate and the acetabular block, followed by 45º rotation during testing, and then thickness of the plate. Conclusion. To enhance fixation of the Kerboull-type plate with cemented acetabular cup, penetration of cement into the outer side of the Kerboull-type plate should be minimised. Key words: acetabulum; transplantation
bone
cements;
bone
INTRODUCTION Reconstruction of the acetabulum involves the use of support rings (Muller support rings, BurchSchneider support rings, and Ganz plates), largediameter cementless cups, and cemented cups with impaction bone grafting. The Kerboull acetabular
Address correspondence and reprint requests to: Dr Nobuhiro Kaku, Department of Orthopaedic Surgery, Faculty of Medicine, Oita University, Oita, Japan. Email: [email protected]
Journal of Orthopaedic Surgery
348 N Kaku et al.
(a)
(b)
(c)
(d)
Figure 1 (a) Experimental materials comprise a simulated acetabular block, a simulated Kerboull-type plate, a pressuriser cover, a pressuriser arm, and bone cement. (b) In condition 1, a 1-mm plate was used with no gap between the plate and the acetabular block. (c) In condition 2, a 2.5-mm plate was used with no gap. (d) In condition 3, a 2.5-mm plate was used with a 2-mm gap.
reinforcement device consists of a stainless steel cup. The titanium Kerboull-type plate is its modification and can be filled with bone grafts to help guide the defective acetabulum to a suitable cup position. Furthermore, a slightly elevated placement of the plate enables variations in acetabular reconstruction. For acetabular reconstruction, the Kerboull-type plate is fixed by screws at the ilium and by a hook at the superior aspect of the obturator foramen. The Kerboull-type plate and the acetabular cup are fixed with bone cement. The Kerboull-type plate has achieved favourable outcomes, but its fixation is generally complicated and can be displaced by impingement.1–7 This study evaluated the fixation strength at the interface between the Kerboull-type plate and bone cement in 6 experimental conditions. MATERIALS AND METHODS The fixation strength at the interface between the Kerboull-type plate and bone cement was determined by the quantity of bone grafts, and cement coverage on the outer and inner surfaces of the Kerboull-type plate. Experimental materials comprised a simulated acetabular block, a simulated Kerboull-type plate, a pressuriser cover, a pressuriser arm, and bone cement (Endurance; DePuy CMW, Blackpool, UK). The environmental temperature during experiments was
Force
Length
Figure 2 Pulling tests are performed to measure the fixation strength at the interface between the simulated Kerboulltype plate and the bone cement.
28ºC to 29ºC. The fixation strength was tested using a universal testing machine (AG-100kNE; Shimadzu, Japan); the pulling speed was 1 mm/min. The simulated Kerboull-type plate was placed on the simulated acetabular block, with the pressuriser cover. Bone cement was added and the pressuriser arm was inserted (Fig. 1). After 6 days of curing,
Vol. 22 No. 3, December 2014
Fixation strength at the interface between Kerboull-type plate and bone cement 349
(a)
(b)
(d)
(c)
Superior
(e) Superior
Superior
(f)
Figure 3 After the pulling tests, in (a) condition 1 and (b) condition 2, no bone cement is left in the simulated acetabular block. (c) In condition 3, some bone cement is left in the superior half of the simulated acetabular block. (d) In condition 4, no plate is used and the bone cement detaches without testing. (e) In condition 5, some bone cement is left in the superior threequarters of the simulated acetabular block. (f) In condition 6, the bone cement cracks and the pressuriser arm detaches.
pulling tests were performed to measure the fixation strength at the interface between the plate and the bone cement (Fig. 2). Six experimental conditions were evaluated. In condition 1, a 1-mm plate was used, with no gap between the plate and the acetabular block. In condition 2, a 2.5-mm plate was used, with no gap. In condition 3, a 2.5-mm plate was used with a 2-mm gap. In condition 4, the plate was not used. In condition 5, condition 2 was tested with the model rotated 45º. In condition 6, condition 3 was tested with the model rotated 45º.
testing, and then thickness of the plate. DISCUSSION Methods to improve micro-interlock adhesion of bone and cement include environmental controls (such as regulation of circulatory dynamics, room temperature, and cement storage temperature); creation of confined spaces for drilling, osteophyte resection, and bone grafting; creation of anchoring holes; bone preparation (such as pulse cleaning and
RESULTS
180 160 140
Load (N)
After the pulling tests, in conditions 1 and 2, no bone cement was left in the simulated acetabular block. In condition 3, some bone cement was left in the superior half of the simulated acetabular block. In condition 4, no plate was used and the bone cement detached without testing. In condition 5, some bone cement was left in the superior three-quarters of the simulated acetabular block. In condition 6, the bone cement cracked and the pressuriser arm detached (Fig. 3). The maximum fixation strengths in conditions 1, 2, 3, 5, and 6 were 44.4 N, 59.1 N, 122.5 N, 86.9 N, and 185.2 N, respectively (Fig. 4). The most important factor affecting the maximum fixation strength was bone cement at the interface between the plate and the acetabular block, followed by 45º rotation during
200
120 100 80 Condition 1
60
Condition 2
40
Condition 3 Condition 5
20 0
Condition 6
0
5
10
15
20
25
30
35
40
45
Displacement (mm)
Figure 4 The displacement-load curves of test conditions 1 to 6.
Journal of Orthopaedic Surgery
350 N Kaku et al.
drying); cement filling (such as vacuum mixing and continuous pressurisation); and adequate pressurisation by using cemented polyethylene cups with flares. In clinical situations, the presence of blood decreases the fixation strength of bone cement. In hip joints fixed with morsellised and structural grafts, the re-implantation rate is low in the short-tomedium term.2-4 The incidence of loosening is higher when morsellised bone grafts are used for large bone defects.5,6 Bone defects of ≤25 mm in height are acceptable for use of morsellised bone.
CONCLUSION To enhance fixation of the Kerboull-type plate with cemented acetabular cup, penetration of cement into the outer side of the Kerboull-type plate should be minimised. DISCLOSURE No conflicts of interest were declared by the authors.
REFERENCES 1. Tradonsky S, Postak PD, Froimson AI, Greenwald AS. A comparison of the disassociation strength of modular acetabular components. Clin Orthop Relat Res 1993;296:154−60. 2. Kerboull M, Hamadouche M, Kerboull L. The Kerboull acetabular reinforcement device in major acetabular reconstructions. Clin Orthop Relat Res 2000;378:155−68. 3. Tanaka C, Shikata J, Ikenaga M, Takahashi M. Acetabular reconstruction using a Kerboull-type acetabular reinforcement device and hydroxyapatite granules: a 3- to 8-year follow-up study. J Arthroplasty 2003;18:719−25. 4. Lunn JV, Kearns SS, Quinlan W, Murray P, Byrne JO. Impaction allografting and the Kerboull acetabular reinforcement device: 35 hips followed for 3-7 years. Acta Orthop 2005;76:296−302. 5. Kawanabe K, Akiyama H, Onishi E, Nakamura T. Revision total hip replacement using the Kerboull acetabular reinforcement device with morsellised or bulk graft: results at a mean follow-up of 8.7 years. J Bone Joint Surg Br 2007;89:26−31. 6. Okano K, Miyata N, Enomoto H, Osaki M, Shindo H. Revision with impacted bone allografts and the Kerboull cross plate for massive bone defect of the acetabulum. J Arthroplasty 2010;25:594−9. 7. Akiyama H, Yamamoto K, Tsukanaka M, Kawanabe K, Otsuka H, So K, et al. Revision total hip arthroplasty using a Kerboulltype acetabular reinforcement device with bone allograft: minimum 4.5-year follow-up results and mechanical analysis. J Bone Joint Surg Br 2011;93:1194−200.
Fixation strength at the interface between Kerboull-type plate and bone cement Nobuhiro Kaku, Katsutoshi Hara, Tomonori Tabata, Hiroshi Tsumura
Department of Orthopaedic Surgery, Faculty of Medicine, Oita University, Oita, Japan.
ABSTRACT Purpose. To evaluate the fixation strength at the interface between the Kerboull-type plate and bone cement in 6 experimental conditions. Methods. Experimental materials comprised a simulated acetabular block, a simulated Kerboulltype plate, a pressuriser cover, a pressuriser arm, and bone cement. The simulated Kerboull-type plate was placed on the simulated acetabular block, with the pressuriser cover. Bone cement was added and the pressuriser arm was inserted. After 6 days of curing, pulling tests were performed to measure the fixation strength at the interface between the plate and the bone cement. Six experimental conditions were evaluated. In condition 1, a 1-mm plate was used with no gap between the plate and the acetabular block. In condition 2, a 2.5-mm plate was used with no gap. In condition 3, a 2.5-mm plate was used with a 2-mm gap. In condition 4, the plate was not used. In condition 5, condition 2 was tested with the model rotated 45º. In condition 6, condition 3 was tested
with the model rotated 45º. Results. The maximum fixation strengths in conditions 1, 2, 3, 5, and 6 were 44.4 N, 59.1 N, 122.5 N, 86.9 N, and 185.2 N, respectively. The most important factor affecting the maximum fixation strength was bone cement at the interface between the plate and the acetabular block, followed by 45º rotation during testing, and then thickness of the plate. Conclusion. To enhance fixation of the Kerboull-type plate with cemented acetabular cup, penetration of cement into the outer side of the Kerboull-type plate should be minimised. Key words: acetabulum; transplantation
bone
cements;
bone
INTRODUCTION Reconstruction of the acetabulum involves the use of support rings (Muller support rings, BurchSchneider support rings, and Ganz plates), largediameter cementless cups, and cemented cups with impaction bone grafting. The Kerboull acetabular
Address correspondence and reprint requests to: Dr Nobuhiro Kaku, Department of Orthopaedic Surgery, Faculty of Medicine, Oita University, Oita, Japan. Email: [email protected]
Journal of Orthopaedic Surgery
348 N Kaku et al.
(a)
(b)
(c)
(d)
Figure 1 (a) Experimental materials comprise a simulated acetabular block, a simulated Kerboull-type plate, a pressuriser cover, a pressuriser arm, and bone cement. (b) In condition 1, a 1-mm plate was used with no gap between the plate and the acetabular block. (c) In condition 2, a 2.5-mm plate was used with no gap. (d) In condition 3, a 2.5-mm plate was used with a 2-mm gap.
reinforcement device consists of a stainless steel cup. The titanium Kerboull-type plate is its modification and can be filled with bone grafts to help guide the defective acetabulum to a suitable cup position. Furthermore, a slightly elevated placement of the plate enables variations in acetabular reconstruction. For acetabular reconstruction, the Kerboull-type plate is fixed by screws at the ilium and by a hook at the superior aspect of the obturator foramen. The Kerboull-type plate and the acetabular cup are fixed with bone cement. The Kerboull-type plate has achieved favourable outcomes, but its fixation is generally complicated and can be displaced by impingement.1–7 This study evaluated the fixation strength at the interface between the Kerboull-type plate and bone cement in 6 experimental conditions. MATERIALS AND METHODS The fixation strength at the interface between the Kerboull-type plate and bone cement was determined by the quantity of bone grafts, and cement coverage on the outer and inner surfaces of the Kerboull-type plate. Experimental materials comprised a simulated acetabular block, a simulated Kerboull-type plate, a pressuriser cover, a pressuriser arm, and bone cement (Endurance; DePuy CMW, Blackpool, UK). The environmental temperature during experiments was
Force
Length
Figure 2 Pulling tests are performed to measure the fixation strength at the interface between the simulated Kerboulltype plate and the bone cement.
28ºC to 29ºC. The fixation strength was tested using a universal testing machine (AG-100kNE; Shimadzu, Japan); the pulling speed was 1 mm/min. The simulated Kerboull-type plate was placed on the simulated acetabular block, with the pressuriser cover. Bone cement was added and the pressuriser arm was inserted (Fig. 1). After 6 days of curing,
Vol. 22 No. 3, December 2014
Fixation strength at the interface between Kerboull-type plate and bone cement 349
(a)
(b)
(d)
(c)
Superior
(e) Superior
Superior
(f)
Figure 3 After the pulling tests, in (a) condition 1 and (b) condition 2, no bone cement is left in the simulated acetabular block. (c) In condition 3, some bone cement is left in the superior half of the simulated acetabular block. (d) In condition 4, no plate is used and the bone cement detaches without testing. (e) In condition 5, some bone cement is left in the superior threequarters of the simulated acetabular block. (f) In condition 6, the bone cement cracks and the pressuriser arm detaches.
pulling tests were performed to measure the fixation strength at the interface between the plate and the bone cement (Fig. 2). Six experimental conditions were evaluated. In condition 1, a 1-mm plate was used, with no gap between the plate and the acetabular block. In condition 2, a 2.5-mm plate was used, with no gap. In condition 3, a 2.5-mm plate was used with a 2-mm gap. In condition 4, the plate was not used. In condition 5, condition 2 was tested with the model rotated 45º. In condition 6, condition 3 was tested with the model rotated 45º.
testing, and then thickness of the plate. DISCUSSION Methods to improve micro-interlock adhesion of bone and cement include environmental controls (such as regulation of circulatory dynamics, room temperature, and cement storage temperature); creation of confined spaces for drilling, osteophyte resection, and bone grafting; creation of anchoring holes; bone preparation (such as pulse cleaning and
RESULTS
180 160 140
Load (N)
After the pulling tests, in conditions 1 and 2, no bone cement was left in the simulated acetabular block. In condition 3, some bone cement was left in the superior half of the simulated acetabular block. In condition 4, no plate was used and the bone cement detached without testing. In condition 5, some bone cement was left in the superior three-quarters of the simulated acetabular block. In condition 6, the bone cement cracked and the pressuriser arm detached (Fig. 3). The maximum fixation strengths in conditions 1, 2, 3, 5, and 6 were 44.4 N, 59.1 N, 122.5 N, 86.9 N, and 185.2 N, respectively (Fig. 4). The most important factor affecting the maximum fixation strength was bone cement at the interface between the plate and the acetabular block, followed by 45º rotation during
200
120 100 80 Condition 1
60
Condition 2
40
Condition 3 Condition 5
20 0
Condition 6
0
5
10
15
20
25
30
35
40
45
Displacement (mm)
Figure 4 The displacement-load curves of test conditions 1 to 6.
Journal of Orthopaedic Surgery
350 N Kaku et al.
drying); cement filling (such as vacuum mixing and continuous pressurisation); and adequate pressurisation by using cemented polyethylene cups with flares. In clinical situations, the presence of blood decreases the fixation strength of bone cement. In hip joints fixed with morsellised and structural grafts, the re-implantation rate is low in the short-tomedium term.2-4 The incidence of loosening is higher when morsellised bone grafts are used for large bone defects.5,6 Bone defects of ≤25 mm in height are acceptable for use of morsellised bone.
CONCLUSION To enhance fixation of the Kerboull-type plate with cemented acetabular cup, penetration of cement into the outer side of the Kerboull-type plate should be minimised. DISCLOSURE No conflicts of interest were declared by the authors.
REFERENCES 1. Tradonsky S, Postak PD, Froimson AI, Greenwald AS. A comparison of the disassociation strength of modular acetabular components. Clin Orthop Relat Res 1993;296:154−60. 2. Kerboull M, Hamadouche M, Kerboull L. The Kerboull acetabular reinforcement device in major acetabular reconstructions. Clin Orthop Relat Res 2000;378:155−68. 3. Tanaka C, Shikata J, Ikenaga M, Takahashi M. Acetabular reconstruction using a Kerboull-type acetabular reinforcement device and hydroxyapatite granules: a 3- to 8-year follow-up study. J Arthroplasty 2003;18:719−25. 4. Lunn JV, Kearns SS, Quinlan W, Murray P, Byrne JO. Impaction allografting and the Kerboull acetabular reinforcement device: 35 hips followed for 3-7 years. Acta Orthop 2005;76:296−302. 5. Kawanabe K, Akiyama H, Onishi E, Nakamura T. Revision total hip replacement using the Kerboull acetabular reinforcement device with morsellised or bulk graft: results at a mean follow-up of 8.7 years. J Bone Joint Surg Br 2007;89:26−31. 6. Okano K, Miyata N, Enomoto H, Osaki M, Shindo H. Revision with impacted bone allografts and the Kerboull cross plate for massive bone defect of the acetabulum. J Arthroplasty 2010;25:594−9. 7. Akiyama H, Yamamoto K, Tsukanaka M, Kawanabe K, Otsuka H, So K, et al. Revision total hip arthroplasty using a Kerboulltype acetabular reinforcement device with bone allograft: minimum 4.5-year follow-up results and mechanical analysis. J Bone Joint Surg Br 2011;93:1194−200.
