THEKNE-01890; No of Pages 4 The Knee xxx (2014) xxx–xxx
Contents lists available at ScienceDirect
The Knee
Case report
Fracture of titanium nitride-coated femoral component after total knee arthroplasty Se-Wook Park, Hyungsuk Kim, Yong In ⁎ Department of Orthopaedic Surgery, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Republic of Korea
a r t i c l e
i n f o
Article history: Received 18 January 2014 Received in revised form 25 March 2014 Accepted 1 April 2014 Available online xxxx Keywords: Total knee arthroplasty Fracture Femoral component Titanium nitride coating
a b s t r a c t We report a case of fracture of a titanium nitride-coated femoral component 3 years after primary total knee arthroplasty (TKA). The fracture was at the medial condylar area just posterior to the medial peg of the femoral component. The backside of the broken medial condylar portion of the femoral component was devoid of cement. Debonding of the component is a possible cause of the stress fracture. To our knowledge, this is the first case report of the fracture of the femoral component manufactured from titanium alloy. Level of evidence: IV © 2014 Elsevier B.V. All rights reserved.
1. Introduction Fracture of the femoral component after total knee arthroplasty (TKA) has been reported [1–8]. Initial reports were limited to a specific implant, the cementless double-beaded layered Ortholoc II prosthesis (Dow Corning Wright, Arlington, TN) and the failure mechanism leading to component fracture was closely related with design and manufacturing features [6–8]. Thereafter, femoral component stress fracture has subsequently been reported with other implants, such as the mobile bearing Low Contact Stress (LCS) prosthesis (DePuy, Johnson & Johnson, Raynham, MA) [1–3] and the fixed bearing Genesis prosthesis (Smith & Nephew, Memphis, TN) [4,5]. The B-P™ total knee system (Endotec, Orlando, FL) was developed by the same doctors who developed the New Jersey LCS total knee system. While maintaining the mobile bearing system, all the metal components of the B-P™ knee system are manufactured from titanium alloy (Ti–6Al–4V) and coated with titanium nitride to increase the wear and scratch resistance. The femoral component is designed to replace the complex geometry of the femoral articular surface while maintaining an anatomical valgus angle. The radii of curvature decrease from anterior to posterior in a coordinated fashion to provide full flexion while maintaining excellent bearing congruity with the tibial component.
⁎ Corresponding author at: Department of Orthopaedic Surgery, Seoul St. Mary's Hospital, The Catholic University of Korea, 222 Banpo-Daero, Seocho-Gu, Seoul 137-701, Republic of Korea. Tel.: +82 2 2258 2838; fax: +82 2 535 9834. E-mail address: [email protected] (Y. In).
We report here on a case of femoral component fracture occurring 3 years after the primary implantation of a cemented B-P™ mobile bearing knee prosthesis. 2. Case report A 56-year-old woman (height; 157, weight; 64 kg, body mass index; 25.96 kg/m2) underwent a TKA in November 2010 due to severe osteoarthritis (OA) of the right knee by another doctor at the authors' institution. She received a posterior cruciate ligament preserving mobile bearing TKA with a B-P™ total knee system. The patella was resurfaced and all implants were cemented. For the cementing of the femoral component, cement was applied onto the anterior and distal condylar cut surfaces of the femur and posterior flanges of the prosthesis. For the cementing of the tibial and patellar components, cement was applied onto the cut surfaces of the tibia and patella as well as the backsides of the prostheses. Preoperative radiographs showed severe OA with the collapse of the medial compartment. Immediate postoperative radiographs showed well fixed femoral and tibial components with 5.3° of valgus alignment. There was no implant overhang on postoperative radiographs. One unusual thing was that the polyethylene thickness was 17 mm, even though it was a primary TKA. At 6 month follow-up, posterior femoral radiolucent line was doubted on radiographs (Fig. 1A, B). At 18 month follow-up, definite anterior and posterior femoral radiolucent lines were noted on radiographs (Fig. 1C, D). In November 2013, after the retirement of the surgeon who had performed the operation, she visited the senior author's clinic with painful swelling on her right knee after walking for several hours. She was unable to extend her right knee fully. Her symptoms started
http://dx.doi.org/10.1016/j.knee.2014.04.002 0968-0160/© 2014 Elsevier B.V. All rights reserved.
Please cite this article as: Park S-W, et al, Fracture of titanium nitride-coated femoral component after total knee arthroplasty, Knee (2014), http:// dx.doi.org/10.1016/j.knee.2014.04.002
2
S.-W. Park et al. / The Knee xxx (2014) xxx–xxx
the medial condylar portion of the femoral component was fractured just posterior to the medial peg (Fig. 2A). The femoral component was loose and was easily removed manually. Although the tibial component was removed using an osteotome, the patellar component was easily removed manually. The retrieved femoral and tibial component sizes were both number 2. The backside of the trochlear and medial condylar portion of the femoral component was debonded from the cement (Fig. 2B, C). After curetting the osteolytic area and removing the rest of the cement from the bones, there were bone defects on both femoral condyles with depression. By Anderson Orthopaedic Research Institute (AORI) classification [9], there were type 2b bone defect on the femur and type 1 bone defect on the tibia (Fig. 2D). We reimplanted new components of a Nexgen revision knee system (Zimmer, Warsaw, IN). We used medial and lateral femoral metal augments with 5 mm thickness distally and posteriorly. Although there was minimal bone loss on the tibia, we used medial and lateral tibial metal blocks of 5 mm in thickness to avoid the use of thicker polyethylene. The flexion and extension gaps were well balanced without mediolateral instability. Considering the patient's age, we used a PS (posterior stabilized) tibial insert (Fig. 3A, B). After the operation, we meticulously reviewed the pre-revision radiographs and detected a crack at the fracture site of the femoral component on the latest lateral radiograph (Fig. 1F). Postoperative recovery was uneventful without pain. 3. Discussion
Fig. 1. Serial pre-revision anteroposterior and lateral radiographs. At 6 months postoperatively (A, B), lateral radiograph shows doubtful radiolucent line on the posterior condylar area of the femur. At 18 months postoperatively (C, D), lateral radiograph shows definite radiolucent lines anteriorly and posteriorly. At 36 months postoperatively (E, F), radiographs show a loosening of the femoral component with the collapse in varus position. Retrospectively a fracture line was found on the lateral radiograph (F).
6 months ago without trauma. She said that she could extend her knee fully and flex up to 130° before the onset of the symptoms. On reviewing her medical records, her postoperative course was unremarkable. She had no history of readmission or manipulation after surgery. Radiographs showed a loosening of the femoral component with collapse in to a varus position (Fig. 1E, F). We explained the situation to the patient and scheduled revision surgery. We planned the removal of all implants and reinsertion of revision knee implants. During the revision procedure we found that
With the improvement of metal alloy manufacturing technology in the arthroplasty industry, fracture of the femoral component has become a rare complication [5]. Initial cases reported involved the same Ortholoc II prosthesis with a double coating layer [6–8]. The thickness of the small size femoral component of the Ortholoc II system was only 3 mm, which was significantly less than that of any other implant available at that time. The mechanism of failure was considered to be a stress fracture localized to the junction between the beveled surface and the posterior flange with insufficient porous fixation [7]. Since then, fracture of the femoral component has been reported in a few implants including the LCS, Genesis and PFC (DePuy, Johnson & Johnson, Raynham, MA) prostheses [1–5,10]. The common mechanism of failure was a stress fracture of the cemented femoral component following extensive osteolysis of the supporting bone. To the best of our knowledge, there has been no previous report on the fracture of the femoral component manufactured from titanium alloy. The metal component of the B-P™ total knee system is made of titanium alloy with titanium nitride ceramic coatings to increase the wear and scratch resistance. New titanium alloys have a suitable mechanical property for artificial implants, with low Young's modulus and high fatigue strength [11]. Both the surgical technique and implant design can be considered as contributing factors to the failure of the femoral component. In this patient, despite that it was a primary TKA, tibial insert with 17 mm thickness was used. Soft tissue imbalance with high stress to the femoral component especially on the medial side could lead to early loosening. Cementing technique could also be crucial for the fixation of components, even though it was difficult to identify whether the cementing technique used in this case affected the implant failure or not. The failure mechanism in the present case was considered to be different with previously reported cases. The backside of the trochlear and medial condylar portion of the retrieved femoral component was devoid of cement. Aseptic debonding of the femoral or tibial component has been reported as a cause of early loosening in modern TKA designs [12,13]. Lack of bony contact through the cement might lead to a stress fracture of the medial condylar portion of the femoral component. The femoral component of B-P™ knee system has relatively long posterior chamfer and the pegs of the femoral component locate on the slanted distal portion (Fig. 2C). In the present case, the fracture had occurred at the angled portion between the distal surface and the posterior
Please cite this article as: Park S-W, et al, Fracture of titanium nitride-coated femoral component after total knee arthroplasty, Knee (2014), http:// dx.doi.org/10.1016/j.knee.2014.04.002
S.-W. Park et al. / The Knee xxx (2014) xxx–xxx
3
Fig. 2. After the capsulotomy for the revision surgery, a fracture on the medial condylar portion of the femoral component was found (A). Most of the backside of the femoral component was devoid of cement (B). Lateral view of the fractured femoral component (C). After removal of implants, there were bone defects on both femoral condyles with depression (D).
chamfer of the medial condylar portion of the femoral component. We measured the thickness of the fracture site using digital calipers. Surprisingly, the thickness of the thinnest portion of the fracture site was only 1 mm. Fractographic examination was done to determine the cause of failure. We speculated that the characteristic of the fracture surface was fatigue failure. A crack had been initiated from the inner thinnest margin under debonding condition and propagated to the mid-portion with striation (slow fracture zone), and finally a fracture
Fig. 3. We used distal and posterior metal blocks for femoral component and proximal metal blocks for tibial component with stem extension (A, B).
occurred at the mid to outer portion of the femoral component (fast fracture zone) (Fig. 4). We recommend an investigation on the design of the femoral component of the B-P™ knee system including implant thickness and surface finish to the manufacturer. Fracture of a femoral component after TKA can be a rare cause for revision surgery. Furthermore, early detection is difficult because the fracture of the femoral component is not easily seen on follow-up radiographs. Anyhow, we believe that early intervention should be considered in case of early loosening of the TKA implants. In the present case, we report a case of fatigue fracture of titanium nitrite coated femoral component with debonding, which was considered to be a possible mechanism of failure.
Fig. 4. Fracture surface shows characteristics of fatigue failure.
Please cite this article as: Park S-W, et al, Fracture of titanium nitride-coated femoral component after total knee arthroplasty, Knee (2014), http:// dx.doi.org/10.1016/j.knee.2014.04.002
4
S.-W. Park et al. / The Knee xxx (2014) xxx–xxx
Conflict of interest statement Each author certifies that he has no commercial associations (e.g., consultancies, stock ownership, equity interest, patent/licensing arrangements) that might pose a conflict of interest in connection with the submitted article. References [1] Han CD, Han CW, Yang IH. Femoral component fracture due to osteolysis after cemented mobile-bearing total knee arthroplasty. J Arthroplasty 2009;24(323):e7-12. [2] Huang CH, Yang CY, Cheng CK. Fracture of the femoral component associated with polyethylene wear and osteolysis after total knee arthroplasty. J Arthroplasty 1999;14:375–9. [3] Lemaire R. Fatigue fracture of the femoral component in a mobile bearing knee prosthesis. Acta Orthop Belg 2010;76:274–81. [4] Luring C, Perlick L, Schubert T, Tingart M. A rare cause for knee pain: fracture of the femoral component after TKR. A case report. Knee Surg Sports Traumatol Arthrosc 2007;15:756–7.
[5] Michos J, Rallis J, Fassoulas A. Fracture of femoral component in a resurfacing total knee arthroplasty. J Arthroplasty 2006;21:1068–71. [6] Swarts E, Miller SJ, Keogh CV, Lim G, Beaver RJ. Fractured Whiteside Ortholoc II knee components. J Arthroplasty 2001;16:927–34. [7] Wada M, Imura S, Bo A, Baba H, Miyazaki T. Stress fracture of the femoral component in total knee replacement: a report of 3 cases. Int Orthop 1997;21:54–5. [8] Whiteside LA, Fosco DR, Brooks Jr JG. Fracture of the femoral component in cementless total knee arthroplasty. Clin Orthop Relat Res 1993;286:71–7. [9] Engh GA. Bone defect classification. In: Engh GA, Rorabeck CH, editors. Revision total knee arthroplasty. Baltimore, MD: Lippincott Williams & Wilkins; 1997. p. 63–120. [10] Duffy GP, Murray BE, Trousdale RR. Hybrid total knee arthroplasty analysis of component failures at an average of 15 years. J Arthroplasty 2007;22:1112–5. [11] Guillemot F. Recent advances in the design of titanium alloys for orthopedic applications. Expert Rev Med Devices 2005;2:741–8. [12] Arsoy D, Pagnano MW, Lewallen DG, Hanssen AD, Sierra RJ. Aseptic tibial debonding as a cause of early failure in a modern total knee arthroplasty design. Clin Orthop Relat Res 2013;471:94–101. [13] Han HS, Kang SB, Yoon KS. High incidence of loosening of the femoral component in legacy posterior stabilised-flex total knee replacement. J Bone Joint Surg [Br] 2007; 89:1457–61.
Please cite this article as: Park S-W, et al, Fracture of titanium nitride-coated femoral component after total knee arthroplasty, Knee (2014), http:// dx.doi.org/10.1016/j.knee.2014.04.002
Contents lists available at ScienceDirect
The Knee
Case report
Fracture of titanium nitride-coated femoral component after total knee arthroplasty Se-Wook Park, Hyungsuk Kim, Yong In ⁎ Department of Orthopaedic Surgery, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Republic of Korea
a r t i c l e
i n f o
Article history: Received 18 January 2014 Received in revised form 25 March 2014 Accepted 1 April 2014 Available online xxxx Keywords: Total knee arthroplasty Fracture Femoral component Titanium nitride coating
a b s t r a c t We report a case of fracture of a titanium nitride-coated femoral component 3 years after primary total knee arthroplasty (TKA). The fracture was at the medial condylar area just posterior to the medial peg of the femoral component. The backside of the broken medial condylar portion of the femoral component was devoid of cement. Debonding of the component is a possible cause of the stress fracture. To our knowledge, this is the first case report of the fracture of the femoral component manufactured from titanium alloy. Level of evidence: IV © 2014 Elsevier B.V. All rights reserved.
1. Introduction Fracture of the femoral component after total knee arthroplasty (TKA) has been reported [1–8]. Initial reports were limited to a specific implant, the cementless double-beaded layered Ortholoc II prosthesis (Dow Corning Wright, Arlington, TN) and the failure mechanism leading to component fracture was closely related with design and manufacturing features [6–8]. Thereafter, femoral component stress fracture has subsequently been reported with other implants, such as the mobile bearing Low Contact Stress (LCS) prosthesis (DePuy, Johnson & Johnson, Raynham, MA) [1–3] and the fixed bearing Genesis prosthesis (Smith & Nephew, Memphis, TN) [4,5]. The B-P™ total knee system (Endotec, Orlando, FL) was developed by the same doctors who developed the New Jersey LCS total knee system. While maintaining the mobile bearing system, all the metal components of the B-P™ knee system are manufactured from titanium alloy (Ti–6Al–4V) and coated with titanium nitride to increase the wear and scratch resistance. The femoral component is designed to replace the complex geometry of the femoral articular surface while maintaining an anatomical valgus angle. The radii of curvature decrease from anterior to posterior in a coordinated fashion to provide full flexion while maintaining excellent bearing congruity with the tibial component.
⁎ Corresponding author at: Department of Orthopaedic Surgery, Seoul St. Mary's Hospital, The Catholic University of Korea, 222 Banpo-Daero, Seocho-Gu, Seoul 137-701, Republic of Korea. Tel.: +82 2 2258 2838; fax: +82 2 535 9834. E-mail address: [email protected] (Y. In).
We report here on a case of femoral component fracture occurring 3 years after the primary implantation of a cemented B-P™ mobile bearing knee prosthesis. 2. Case report A 56-year-old woman (height; 157, weight; 64 kg, body mass index; 25.96 kg/m2) underwent a TKA in November 2010 due to severe osteoarthritis (OA) of the right knee by another doctor at the authors' institution. She received a posterior cruciate ligament preserving mobile bearing TKA with a B-P™ total knee system. The patella was resurfaced and all implants were cemented. For the cementing of the femoral component, cement was applied onto the anterior and distal condylar cut surfaces of the femur and posterior flanges of the prosthesis. For the cementing of the tibial and patellar components, cement was applied onto the cut surfaces of the tibia and patella as well as the backsides of the prostheses. Preoperative radiographs showed severe OA with the collapse of the medial compartment. Immediate postoperative radiographs showed well fixed femoral and tibial components with 5.3° of valgus alignment. There was no implant overhang on postoperative radiographs. One unusual thing was that the polyethylene thickness was 17 mm, even though it was a primary TKA. At 6 month follow-up, posterior femoral radiolucent line was doubted on radiographs (Fig. 1A, B). At 18 month follow-up, definite anterior and posterior femoral radiolucent lines were noted on radiographs (Fig. 1C, D). In November 2013, after the retirement of the surgeon who had performed the operation, she visited the senior author's clinic with painful swelling on her right knee after walking for several hours. She was unable to extend her right knee fully. Her symptoms started
http://dx.doi.org/10.1016/j.knee.2014.04.002 0968-0160/© 2014 Elsevier B.V. All rights reserved.
Please cite this article as: Park S-W, et al, Fracture of titanium nitride-coated femoral component after total knee arthroplasty, Knee (2014), http:// dx.doi.org/10.1016/j.knee.2014.04.002
2
S.-W. Park et al. / The Knee xxx (2014) xxx–xxx
the medial condylar portion of the femoral component was fractured just posterior to the medial peg (Fig. 2A). The femoral component was loose and was easily removed manually. Although the tibial component was removed using an osteotome, the patellar component was easily removed manually. The retrieved femoral and tibial component sizes were both number 2. The backside of the trochlear and medial condylar portion of the femoral component was debonded from the cement (Fig. 2B, C). After curetting the osteolytic area and removing the rest of the cement from the bones, there were bone defects on both femoral condyles with depression. By Anderson Orthopaedic Research Institute (AORI) classification [9], there were type 2b bone defect on the femur and type 1 bone defect on the tibia (Fig. 2D). We reimplanted new components of a Nexgen revision knee system (Zimmer, Warsaw, IN). We used medial and lateral femoral metal augments with 5 mm thickness distally and posteriorly. Although there was minimal bone loss on the tibia, we used medial and lateral tibial metal blocks of 5 mm in thickness to avoid the use of thicker polyethylene. The flexion and extension gaps were well balanced without mediolateral instability. Considering the patient's age, we used a PS (posterior stabilized) tibial insert (Fig. 3A, B). After the operation, we meticulously reviewed the pre-revision radiographs and detected a crack at the fracture site of the femoral component on the latest lateral radiograph (Fig. 1F). Postoperative recovery was uneventful without pain. 3. Discussion
Fig. 1. Serial pre-revision anteroposterior and lateral radiographs. At 6 months postoperatively (A, B), lateral radiograph shows doubtful radiolucent line on the posterior condylar area of the femur. At 18 months postoperatively (C, D), lateral radiograph shows definite radiolucent lines anteriorly and posteriorly. At 36 months postoperatively (E, F), radiographs show a loosening of the femoral component with the collapse in varus position. Retrospectively a fracture line was found on the lateral radiograph (F).
6 months ago without trauma. She said that she could extend her knee fully and flex up to 130° before the onset of the symptoms. On reviewing her medical records, her postoperative course was unremarkable. She had no history of readmission or manipulation after surgery. Radiographs showed a loosening of the femoral component with collapse in to a varus position (Fig. 1E, F). We explained the situation to the patient and scheduled revision surgery. We planned the removal of all implants and reinsertion of revision knee implants. During the revision procedure we found that
With the improvement of metal alloy manufacturing technology in the arthroplasty industry, fracture of the femoral component has become a rare complication [5]. Initial cases reported involved the same Ortholoc II prosthesis with a double coating layer [6–8]. The thickness of the small size femoral component of the Ortholoc II system was only 3 mm, which was significantly less than that of any other implant available at that time. The mechanism of failure was considered to be a stress fracture localized to the junction between the beveled surface and the posterior flange with insufficient porous fixation [7]. Since then, fracture of the femoral component has been reported in a few implants including the LCS, Genesis and PFC (DePuy, Johnson & Johnson, Raynham, MA) prostheses [1–5,10]. The common mechanism of failure was a stress fracture of the cemented femoral component following extensive osteolysis of the supporting bone. To the best of our knowledge, there has been no previous report on the fracture of the femoral component manufactured from titanium alloy. The metal component of the B-P™ total knee system is made of titanium alloy with titanium nitride ceramic coatings to increase the wear and scratch resistance. New titanium alloys have a suitable mechanical property for artificial implants, with low Young's modulus and high fatigue strength [11]. Both the surgical technique and implant design can be considered as contributing factors to the failure of the femoral component. In this patient, despite that it was a primary TKA, tibial insert with 17 mm thickness was used. Soft tissue imbalance with high stress to the femoral component especially on the medial side could lead to early loosening. Cementing technique could also be crucial for the fixation of components, even though it was difficult to identify whether the cementing technique used in this case affected the implant failure or not. The failure mechanism in the present case was considered to be different with previously reported cases. The backside of the trochlear and medial condylar portion of the retrieved femoral component was devoid of cement. Aseptic debonding of the femoral or tibial component has been reported as a cause of early loosening in modern TKA designs [12,13]. Lack of bony contact through the cement might lead to a stress fracture of the medial condylar portion of the femoral component. The femoral component of B-P™ knee system has relatively long posterior chamfer and the pegs of the femoral component locate on the slanted distal portion (Fig. 2C). In the present case, the fracture had occurred at the angled portion between the distal surface and the posterior
Please cite this article as: Park S-W, et al, Fracture of titanium nitride-coated femoral component after total knee arthroplasty, Knee (2014), http:// dx.doi.org/10.1016/j.knee.2014.04.002
S.-W. Park et al. / The Knee xxx (2014) xxx–xxx
3
Fig. 2. After the capsulotomy for the revision surgery, a fracture on the medial condylar portion of the femoral component was found (A). Most of the backside of the femoral component was devoid of cement (B). Lateral view of the fractured femoral component (C). After removal of implants, there were bone defects on both femoral condyles with depression (D).
chamfer of the medial condylar portion of the femoral component. We measured the thickness of the fracture site using digital calipers. Surprisingly, the thickness of the thinnest portion of the fracture site was only 1 mm. Fractographic examination was done to determine the cause of failure. We speculated that the characteristic of the fracture surface was fatigue failure. A crack had been initiated from the inner thinnest margin under debonding condition and propagated to the mid-portion with striation (slow fracture zone), and finally a fracture
Fig. 3. We used distal and posterior metal blocks for femoral component and proximal metal blocks for tibial component with stem extension (A, B).
occurred at the mid to outer portion of the femoral component (fast fracture zone) (Fig. 4). We recommend an investigation on the design of the femoral component of the B-P™ knee system including implant thickness and surface finish to the manufacturer. Fracture of a femoral component after TKA can be a rare cause for revision surgery. Furthermore, early detection is difficult because the fracture of the femoral component is not easily seen on follow-up radiographs. Anyhow, we believe that early intervention should be considered in case of early loosening of the TKA implants. In the present case, we report a case of fatigue fracture of titanium nitrite coated femoral component with debonding, which was considered to be a possible mechanism of failure.
Fig. 4. Fracture surface shows characteristics of fatigue failure.
Please cite this article as: Park S-W, et al, Fracture of titanium nitride-coated femoral component after total knee arthroplasty, Knee (2014), http:// dx.doi.org/10.1016/j.knee.2014.04.002
4
S.-W. Park et al. / The Knee xxx (2014) xxx–xxx
Conflict of interest statement Each author certifies that he has no commercial associations (e.g., consultancies, stock ownership, equity interest, patent/licensing arrangements) that might pose a conflict of interest in connection with the submitted article. References [1] Han CD, Han CW, Yang IH. Femoral component fracture due to osteolysis after cemented mobile-bearing total knee arthroplasty. J Arthroplasty 2009;24(323):e7-12. [2] Huang CH, Yang CY, Cheng CK. Fracture of the femoral component associated with polyethylene wear and osteolysis after total knee arthroplasty. J Arthroplasty 1999;14:375–9. [3] Lemaire R. Fatigue fracture of the femoral component in a mobile bearing knee prosthesis. Acta Orthop Belg 2010;76:274–81. [4] Luring C, Perlick L, Schubert T, Tingart M. A rare cause for knee pain: fracture of the femoral component after TKR. A case report. Knee Surg Sports Traumatol Arthrosc 2007;15:756–7.
[5] Michos J, Rallis J, Fassoulas A. Fracture of femoral component in a resurfacing total knee arthroplasty. J Arthroplasty 2006;21:1068–71. [6] Swarts E, Miller SJ, Keogh CV, Lim G, Beaver RJ. Fractured Whiteside Ortholoc II knee components. J Arthroplasty 2001;16:927–34. [7] Wada M, Imura S, Bo A, Baba H, Miyazaki T. Stress fracture of the femoral component in total knee replacement: a report of 3 cases. Int Orthop 1997;21:54–5. [8] Whiteside LA, Fosco DR, Brooks Jr JG. Fracture of the femoral component in cementless total knee arthroplasty. Clin Orthop Relat Res 1993;286:71–7. [9] Engh GA. Bone defect classification. In: Engh GA, Rorabeck CH, editors. Revision total knee arthroplasty. Baltimore, MD: Lippincott Williams & Wilkins; 1997. p. 63–120. [10] Duffy GP, Murray BE, Trousdale RR. Hybrid total knee arthroplasty analysis of component failures at an average of 15 years. J Arthroplasty 2007;22:1112–5. [11] Guillemot F. Recent advances in the design of titanium alloys for orthopedic applications. Expert Rev Med Devices 2005;2:741–8. [12] Arsoy D, Pagnano MW, Lewallen DG, Hanssen AD, Sierra RJ. Aseptic tibial debonding as a cause of early failure in a modern total knee arthroplasty design. Clin Orthop Relat Res 2013;471:94–101. [13] Han HS, Kang SB, Yoon KS. High incidence of loosening of the femoral component in legacy posterior stabilised-flex total knee replacement. J Bone Joint Surg [Br] 2007; 89:1457–61.
Please cite this article as: Park S-W, et al, Fracture of titanium nitride-coated femoral component after total knee arthroplasty, Knee (2014), http:// dx.doi.org/10.1016/j.knee.2014.04.002
