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Long Term Results of Liner Polyethylene Cementation Technique in Revision for Peri-acetabular Osteolysis
The Journal of Arthroplasty 30 (2015) 1041–1043
Contents lists available at ScienceDirect
The Journal of Arthroplasty journal homepage: www.arthroplastyjournal.org
Long Term Results of Liner Polyethylene Cementation Technique in Revision for Peri-acetabular Osteolysis Gurion Rivkin, MD, Leonid Kandel, MD , Bilal Qutteineh, MD, Meir Liebergall, MD, Yoav Mattan, MD Orthopedic Surgery Department, Hadassah Medical Center, Jerusalem, Israel
a r t i c l e
i n f o
Article history: Received 18 August 2014 Accepted 27 January 2015 Keywords: hip arthroplasty revision osteolysis cementation insert exchange
a b s t r a c t Patients with peri-acetabular osteolysis around a well fixed cementless acetabular component may be treated with liner exchange. When the locking mechanism is unreliable or unavailable, cementing the liner into the fixed acetabular component is a feasible option. The purpose of this study was to evaluate the clinical and radiographic long term results of this technique. Forty hip revisions with liner cementation in 37 patients were performed. The minimum follow up was 10 years. Modified Harris Hip Score and recent x rays were reviewed. Four hips were re-revised. Two patients were diagnosed with exacerbation of osteolysis but refused revision. Dislocation rate was relatively high (16%). Liner cementation technique in revision hip surgery is useful in patients with a well fixed metal backed acetabular component. © 2015 Elsevier Inc. All rights reserved.
Hip arthroplasty is a successful treatment of hip arthritis. Increasing life expectancy and increased demand for better quality of life cause a continuous rise in the number of hip arthroplasties, which may lead to an increase of revision surgery. Cementless fixation of acetabular components has been the preferred fixation mode in the USA for decades and it is increasing in countries where cement fixation was the preferred method [1]. Infection and loosening usually result in revision of both femoral and acetabular components. In cases of periacetabular osteolysis and a modular cementless acetabular component, the metal backed acetabulum may be well fixed. These cases may be treated with replacement of the acetabular cup risking damage to bone stock during extraction of the cup or liner exchange retaining the metal backed acetabular shell. Cementing a new liner to an existing acetabular metal shell was described in cases where the cup was deformed or the locking mechanism was non functional or unavailable [2]. We have been using the liner cementation technique for more than a decade and reported our early results [3]. We now describe the long term results in this cohort of patients.
Materials and Methods Between November 1999 and October 2003, 40 hips in 37 patients underwent a cemented revision of the polyethylene liner. Our group No author associated with this paper has disclosed any potential or pertinent conflicts which may be perceived to have impending conflict with this work. For full disclosure statements refer to http://dx.doi.org/10.1016/j.arth.2015.01.041. Reprint requests: Leonid Kandel, MD, Joint Replacement and Reconstruction Unit, Orthopedic Surgery Dept., Hadassah Medical Center, Jerusalem, Israel, P.O.B. 12000, 91120. http://dx.doi.org/10.1016/j.arth.2015.01.041 0883-5403/© 2015 Elsevier Inc. All rights reserved.
previously reported early results with this cohort of patients [3]. We reviewed the records of this cohort again. Compared to our initial report, one patient had died and three were lost to follow up, leaving 33 patients with 36 hips. The mean age at revision was 61 years and that was performed at a mean of 7 years after the primary surgery (range 36–138 months). Twenty three were females with 25 hips, 10 patients were male with 11 hips. Twenty three hips (64%) were right sided, 13 hips (36%) were left sided. The records from the initial hip arthroplasty were not available so we are unable to report the reason for hip arthroplasty. Anatomique Benoist Girard hip prosthesis (ABG I, Howmedica, Inc., Staines, England) was the original implant in 27 patients comprising 75% of the study population. Other prosthesis revised were Harris-Galante (Zimmer, Warsaw, Indiana) in 4 patients (11.1%), PCA (Howmedica, Rutherford, New Jersey) in 3 patients (8.3%), Omnifit (Osteonics, Allendale, New Jersey) in 1 patient and an unknown implant in 1 patient. When radiologic signs of osteolysis were noted on anteroposterior and lateral radiographs, patients underwent a workup for infection including blood tests, bone scans, and hip aspiration. In some cases, if a high-resolution computed tomography (CT) scan was performed, the scan was used to assess the extent and location of the cysts. If the source of the pain was questionable, a lidocaine test was also performed during the hip aspiration, following which the patient was scheduled for surgery. Asymptomatic patients were referred for revision surgery only when radiologic evaluation (CT or radiograph) confirmed a significant or progressive osteolytic process. Liner cementation technique was used only if the acetabular component had not migrated and appeared to be well fixed — the equivalent of Paprosky grade I periacetabular osteolysis [4]. All procedures were performed through a posterolateral approach. After the hip was exposed and dislocated, the polyethylene insert and the screws or pegs were
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G. Rivkin et al. / The Journal of Arthroplasty 30 (2015) 1041–1043
removed. Meticulous soft tissue release around the hip components was done to prevent any pseudo-stability (assessment of component stability based on soft tissue attachments and not on bony ingrowth). Osteolytic cysts were grafted with bone substitute through a “trap door” in the ilium. In all cases, the metal shells had holes, and there was no need to scour them with a burr for better cement bonding. Manual scouring of the outer surface of the new insert was performed. In 17 hips a Longevity insert (Zimmer, Warsaw, Indiana) was used and in 19 hips a Ringloc insert (Biomet, Warsaw, Indiana) was used. An insert that accommodates the biggest femoral head possible (sizes 32 or 36) yet completely embedded in the acetabular shell with a 2 mm cement mantle was chosen. Doughy cement was inserted into the metal back shell followed by the new polyethylene liner insert. Care was taken to assure the liner was positioned in proper alignment. Continued pressure was applied using the liner impactor until the cement hardened. Excess cement extruding around the liner was removed. During the postoperative period, full weight bearing was allowed on the morning following the revision. All patients received VTE prophylaxis with low-molecular-weight heparin and perioperative intravenous antibiotics (usually first generation cephalosporin) for 5 days. All intraoperative cultures were negative. An investigator (BQ) contacted all patients or their siblings in cases of general deterioration. Patients were evaluated by a modified Harris hip score and had AP and lateral pelvis x rays. X rays were evaluated for wear, loosening and further osteolysis progression by two of the authors (GR, LK). Thirty one patients had X-rays (86.1%) available for review with a minimum of 10 years from revision surgery. Our Institutional Review Board approved this study. Results Four hips were re-revised — resulting in 88.9% survival rate at 11 years. One patient suffered an a-traumatic acetabular fracture treated with a hip revision which later developed deep infection necessitating a 2 stage revision. Another patient underwent femoral revision for femoral loosening 6 years after the liner cementation surgery. One patient underwent acetabular revision due to loosening 9 years after surgery, and one patient underwent revision for long standing dislocation comprising an open reduction and liner augmentation (Olerud procedure) 2 months following the liner revision [5]. Six patients (16.6%) suffered a hip dislocation, three in the immediate post op time frame and three other months to years later. Five responded to closed treatment while one patient required revision as mentioned above. Three patients (8.3%) were diagnosed with pulmonary embolism and were treated accordingly. On the last follow up three patients were evaluated for hip pain and had a suspected acetabular cup loosening yet none agreed to surgery so far. Average modified Harris hip scores on last follow up was 84.1 (range 34–100). This same cohort had a modified HHS of 88 at a mean 3 years after surgery [3]. Evaluation of pelvic x rays for wear, loosening or osteolysis worsening revealed none in 17 hips. In 10 hips there was evidence of some degree of wear, signs of loosening in 1 hip and significant osteolysis in 2 hips. At 11 years of follow up there was no dislocation of the cemented liner from the acetabular shell. Discussion Cementless modular hip systems offer the possibilities of using different bearing surfaces and in cases where ultra high molecular weight polyethylene (UHMWPE) is the bearing of choice, the surgeon can choose different head sizes and different designs (neutral or with an elevated rim) [6]. The use of these systems is common and continues to grow. With bone ingrowth to the metal back long term fixation is excellent [7]. However, wear and resultant peri-acetabular osteolysis remain a concern. The osteolytic process should be identified and may warrant
early revision surgery [8,9]. This approach may lead to revision when the acetabular shell is still well fixed and in these cases liner exchange is a possibility [10]. When the locking mechanism is non functional (damaged locking mechanism, unavailable matching liners or deformed metal back shell) cementing the new liner is an option [2,11,12]. This approach has been described and its’ mid term results were also published [13]. To our knowledge there isn’t a longer follow up of a cohort with liner cementation revision. In our series the minimum follow up was 10 years and the mean was more than 11 years (137 months). During all this time no case of dissociation was observed, either from the liner–cement mantle interface or metal back–cement mantle interface. Callaghan et al in similar report of 30 patients also did not find liner dislocation in a mean 5 years of follow up [13]. Although there is literature regarding the strength of the metal shell–cement–liner complex, dissociation of the complex does not seem to be a problem with unconstrained liners. Dislocation following liner cementation revision varies. Beaule et al reported a 22% dislocation rate with liner cementation technique; Callaghan et al reported a 6% dislocation rate with regular postoperative use of an abduction brace or single leg pantaloon casts [2,13]. Six patients in our cohort suffered a hip dislocation — a 16.6% rate. The prerequisite for liner cementation is a well fixed well aligned acetabular shell. These patients are treated for peri-acetabular osteolysis, not hip instability. Yet, revision surgery itself is a risk factor for hip dislocation. Also, unique to this technique is the limitation of available head sizes. Since the liner should completely lie inside the shell and allow for at least 2 mm of cement mantle, the liner size is limited and may not allow increasing the femoral head size. The fact that the liner is cemented and not locked to the locking mechanism may lead to some alteration in version compared to the metal back shell. The surgeon should also be aware of extrusion of cement, especially anterior, which may cause impingement and posterior dislocation. A large 32 or 36 mm femoral head should be used when possible to reduce dislocation risk. Meticulous cleaning of extruded cement remnants at the end of cementation process should be performed. We report an 88% survival rate at a mean of 11 years. If we include patients that are currently being evaluated for hip pain and suspected acetabular loosening as mechanical failures, there would be 29 surviving hips — 80.5% survival rate. Bone loss due to osteolysis may be further complicated by acetabular extraction. Cementation of a new UHMWPE non constrained liner offers a less extensive surgery during which bone defects can be filled with bone graft or bone substitutes to restore bone stock. An 88% 11 year survival rate would be excellent for this kind of revision surgery; 80% would still be a very good result. Some potential weaknesses became apparent during this study. Several classifications were devised to deal with periacetabular osteolysis and bone loss. Most of these rely on plain radiographs and are based on the region of bone loss and migration of the acetabular component. These classification systems provide surgeons with guidance in choice of implants, graft and fixation methods and liner exchange is not an option. However, our study deals with a condition similar to Paprosky type I in which there is only bone loss and no cup migration [4]. We found no classification or radiological study that correlates between the degree of bone loss and long term stability of a well fixed acetabular component. Therefore, we could only rely on clinical judgment pre-operatively and intraoperatively in the decision to keep a well fixed acetabular component. We conclude that in cases of osteolysis around a modular metal backed acetabular cup, a liner revision is a very good option although a relatively high dislocation rate should be considered. The inability to use a matching liner with a locking mechanism should not deter the surgeon and the use of cement will result in a lasting and stable mechanical complex.
References 1. Troelsen A, Malchau E, Sillesen N, et al. A review of current fixation use and registry outcomes in total hip arthroplasty: the uncemented paradox. Clin Orthop Relat Res 2013;471:2052.
G. Rivkin et al. / The Journal of Arthroplasty 30 (2015) 1041–1043 2. Beaule PE, Ebramzadeh E, Le Duff M, et al. Cementing a liner into a stable cementless acetabular shell: the double-socket technique. J Bone Joint Surg Am 2004;86-A:929. 3. Kandel L, Rivkin G, Friedman A, et al. Polyethylene liner cementation technique in asymptomatic versus symptomatic osteolysis. Orthopedics 2009;32:560. 4. Paprosky WG, Perona BG, Lawrence JM. Acetabular defect classification and surgical reconstruction in revision arthroplasty, a 6 year follow up evaluation. J Arthroplasty 1994;9:33. 5. Olerud S, Karlstrom G. Recurrent dislocation after total hip replacement. Treatment by fixing an additional sector to the acetabular component. J Bone Joint Surg (Br) 1985;67:402. 6. Barrack RL. Modularity of prosthetic implants. J Am Acad Orthop Surg 1994;2:16. 7. Della Valle CJ, Berger RA, Shott S, et al. Primary total hip arthroplasty with a porouscoated acetabular component. A concise follow-up of a previous report. J Bone Joint Surg Am 2004;86-A:1217.
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8. Berry DJ. Management of osteolysis around total hip arthroplasty. Orthopedics 1999; 22:805. 9. Beaule PE, Campbell P, Mirra J, et al. Osteolysis in a cementless, second generation metal-on-metal hip replacement. Clin Orthop Relat Res 2001:159. 10. Terefenko KM, Sychterz CJ, Orishimo K, et al. Polyethylene liner exchange for excessive wear and osteolysis. J Arthroplasty 2002;17:798. 11. Haft GF, Jeiner AD, Callaghan JJ, et al. Polyethylene liner cementation into fixed acetabular shells. J Arthroplasty 2002;17:167. 12. Bonner KF, Delanois RE, Harbach G, et al. Cementation of a polyethylene liner into a metal shell. Factors related to mechanical stability. J Bone Joint Surg Am 2002;84-A: 1587. 13. Callaghan JJ, Hennessy DW, Liu SS, et al. Cementing acetabular liners into secure cementless shells for polyethylene wear provides durable mid-term fixation. Clin Orthop Relat Res 2012;470(11):3142.
Contents lists available at ScienceDirect
The Journal of Arthroplasty journal homepage: www.arthroplastyjournal.org
Long Term Results of Liner Polyethylene Cementation Technique in Revision for Peri-acetabular Osteolysis Gurion Rivkin, MD, Leonid Kandel, MD , Bilal Qutteineh, MD, Meir Liebergall, MD, Yoav Mattan, MD Orthopedic Surgery Department, Hadassah Medical Center, Jerusalem, Israel
a r t i c l e
i n f o
Article history: Received 18 August 2014 Accepted 27 January 2015 Keywords: hip arthroplasty revision osteolysis cementation insert exchange
a b s t r a c t Patients with peri-acetabular osteolysis around a well fixed cementless acetabular component may be treated with liner exchange. When the locking mechanism is unreliable or unavailable, cementing the liner into the fixed acetabular component is a feasible option. The purpose of this study was to evaluate the clinical and radiographic long term results of this technique. Forty hip revisions with liner cementation in 37 patients were performed. The minimum follow up was 10 years. Modified Harris Hip Score and recent x rays were reviewed. Four hips were re-revised. Two patients were diagnosed with exacerbation of osteolysis but refused revision. Dislocation rate was relatively high (16%). Liner cementation technique in revision hip surgery is useful in patients with a well fixed metal backed acetabular component. © 2015 Elsevier Inc. All rights reserved.
Hip arthroplasty is a successful treatment of hip arthritis. Increasing life expectancy and increased demand for better quality of life cause a continuous rise in the number of hip arthroplasties, which may lead to an increase of revision surgery. Cementless fixation of acetabular components has been the preferred fixation mode in the USA for decades and it is increasing in countries where cement fixation was the preferred method [1]. Infection and loosening usually result in revision of both femoral and acetabular components. In cases of periacetabular osteolysis and a modular cementless acetabular component, the metal backed acetabulum may be well fixed. These cases may be treated with replacement of the acetabular cup risking damage to bone stock during extraction of the cup or liner exchange retaining the metal backed acetabular shell. Cementing a new liner to an existing acetabular metal shell was described in cases where the cup was deformed or the locking mechanism was non functional or unavailable [2]. We have been using the liner cementation technique for more than a decade and reported our early results [3]. We now describe the long term results in this cohort of patients.
Materials and Methods Between November 1999 and October 2003, 40 hips in 37 patients underwent a cemented revision of the polyethylene liner. Our group No author associated with this paper has disclosed any potential or pertinent conflicts which may be perceived to have impending conflict with this work. For full disclosure statements refer to http://dx.doi.org/10.1016/j.arth.2015.01.041. Reprint requests: Leonid Kandel, MD, Joint Replacement and Reconstruction Unit, Orthopedic Surgery Dept., Hadassah Medical Center, Jerusalem, Israel, P.O.B. 12000, 91120. http://dx.doi.org/10.1016/j.arth.2015.01.041 0883-5403/© 2015 Elsevier Inc. All rights reserved.
previously reported early results with this cohort of patients [3]. We reviewed the records of this cohort again. Compared to our initial report, one patient had died and three were lost to follow up, leaving 33 patients with 36 hips. The mean age at revision was 61 years and that was performed at a mean of 7 years after the primary surgery (range 36–138 months). Twenty three were females with 25 hips, 10 patients were male with 11 hips. Twenty three hips (64%) were right sided, 13 hips (36%) were left sided. The records from the initial hip arthroplasty were not available so we are unable to report the reason for hip arthroplasty. Anatomique Benoist Girard hip prosthesis (ABG I, Howmedica, Inc., Staines, England) was the original implant in 27 patients comprising 75% of the study population. Other prosthesis revised were Harris-Galante (Zimmer, Warsaw, Indiana) in 4 patients (11.1%), PCA (Howmedica, Rutherford, New Jersey) in 3 patients (8.3%), Omnifit (Osteonics, Allendale, New Jersey) in 1 patient and an unknown implant in 1 patient. When radiologic signs of osteolysis were noted on anteroposterior and lateral radiographs, patients underwent a workup for infection including blood tests, bone scans, and hip aspiration. In some cases, if a high-resolution computed tomography (CT) scan was performed, the scan was used to assess the extent and location of the cysts. If the source of the pain was questionable, a lidocaine test was also performed during the hip aspiration, following which the patient was scheduled for surgery. Asymptomatic patients were referred for revision surgery only when radiologic evaluation (CT or radiograph) confirmed a significant or progressive osteolytic process. Liner cementation technique was used only if the acetabular component had not migrated and appeared to be well fixed — the equivalent of Paprosky grade I periacetabular osteolysis [4]. All procedures were performed through a posterolateral approach. After the hip was exposed and dislocated, the polyethylene insert and the screws or pegs were
1042
G. Rivkin et al. / The Journal of Arthroplasty 30 (2015) 1041–1043
removed. Meticulous soft tissue release around the hip components was done to prevent any pseudo-stability (assessment of component stability based on soft tissue attachments and not on bony ingrowth). Osteolytic cysts were grafted with bone substitute through a “trap door” in the ilium. In all cases, the metal shells had holes, and there was no need to scour them with a burr for better cement bonding. Manual scouring of the outer surface of the new insert was performed. In 17 hips a Longevity insert (Zimmer, Warsaw, Indiana) was used and in 19 hips a Ringloc insert (Biomet, Warsaw, Indiana) was used. An insert that accommodates the biggest femoral head possible (sizes 32 or 36) yet completely embedded in the acetabular shell with a 2 mm cement mantle was chosen. Doughy cement was inserted into the metal back shell followed by the new polyethylene liner insert. Care was taken to assure the liner was positioned in proper alignment. Continued pressure was applied using the liner impactor until the cement hardened. Excess cement extruding around the liner was removed. During the postoperative period, full weight bearing was allowed on the morning following the revision. All patients received VTE prophylaxis with low-molecular-weight heparin and perioperative intravenous antibiotics (usually first generation cephalosporin) for 5 days. All intraoperative cultures were negative. An investigator (BQ) contacted all patients or their siblings in cases of general deterioration. Patients were evaluated by a modified Harris hip score and had AP and lateral pelvis x rays. X rays were evaluated for wear, loosening and further osteolysis progression by two of the authors (GR, LK). Thirty one patients had X-rays (86.1%) available for review with a minimum of 10 years from revision surgery. Our Institutional Review Board approved this study. Results Four hips were re-revised — resulting in 88.9% survival rate at 11 years. One patient suffered an a-traumatic acetabular fracture treated with a hip revision which later developed deep infection necessitating a 2 stage revision. Another patient underwent femoral revision for femoral loosening 6 years after the liner cementation surgery. One patient underwent acetabular revision due to loosening 9 years after surgery, and one patient underwent revision for long standing dislocation comprising an open reduction and liner augmentation (Olerud procedure) 2 months following the liner revision [5]. Six patients (16.6%) suffered a hip dislocation, three in the immediate post op time frame and three other months to years later. Five responded to closed treatment while one patient required revision as mentioned above. Three patients (8.3%) were diagnosed with pulmonary embolism and were treated accordingly. On the last follow up three patients were evaluated for hip pain and had a suspected acetabular cup loosening yet none agreed to surgery so far. Average modified Harris hip scores on last follow up was 84.1 (range 34–100). This same cohort had a modified HHS of 88 at a mean 3 years after surgery [3]. Evaluation of pelvic x rays for wear, loosening or osteolysis worsening revealed none in 17 hips. In 10 hips there was evidence of some degree of wear, signs of loosening in 1 hip and significant osteolysis in 2 hips. At 11 years of follow up there was no dislocation of the cemented liner from the acetabular shell. Discussion Cementless modular hip systems offer the possibilities of using different bearing surfaces and in cases where ultra high molecular weight polyethylene (UHMWPE) is the bearing of choice, the surgeon can choose different head sizes and different designs (neutral or with an elevated rim) [6]. The use of these systems is common and continues to grow. With bone ingrowth to the metal back long term fixation is excellent [7]. However, wear and resultant peri-acetabular osteolysis remain a concern. The osteolytic process should be identified and may warrant
early revision surgery [8,9]. This approach may lead to revision when the acetabular shell is still well fixed and in these cases liner exchange is a possibility [10]. When the locking mechanism is non functional (damaged locking mechanism, unavailable matching liners or deformed metal back shell) cementing the new liner is an option [2,11,12]. This approach has been described and its’ mid term results were also published [13]. To our knowledge there isn’t a longer follow up of a cohort with liner cementation revision. In our series the minimum follow up was 10 years and the mean was more than 11 years (137 months). During all this time no case of dissociation was observed, either from the liner–cement mantle interface or metal back–cement mantle interface. Callaghan et al in similar report of 30 patients also did not find liner dislocation in a mean 5 years of follow up [13]. Although there is literature regarding the strength of the metal shell–cement–liner complex, dissociation of the complex does not seem to be a problem with unconstrained liners. Dislocation following liner cementation revision varies. Beaule et al reported a 22% dislocation rate with liner cementation technique; Callaghan et al reported a 6% dislocation rate with regular postoperative use of an abduction brace or single leg pantaloon casts [2,13]. Six patients in our cohort suffered a hip dislocation — a 16.6% rate. The prerequisite for liner cementation is a well fixed well aligned acetabular shell. These patients are treated for peri-acetabular osteolysis, not hip instability. Yet, revision surgery itself is a risk factor for hip dislocation. Also, unique to this technique is the limitation of available head sizes. Since the liner should completely lie inside the shell and allow for at least 2 mm of cement mantle, the liner size is limited and may not allow increasing the femoral head size. The fact that the liner is cemented and not locked to the locking mechanism may lead to some alteration in version compared to the metal back shell. The surgeon should also be aware of extrusion of cement, especially anterior, which may cause impingement and posterior dislocation. A large 32 or 36 mm femoral head should be used when possible to reduce dislocation risk. Meticulous cleaning of extruded cement remnants at the end of cementation process should be performed. We report an 88% survival rate at a mean of 11 years. If we include patients that are currently being evaluated for hip pain and suspected acetabular loosening as mechanical failures, there would be 29 surviving hips — 80.5% survival rate. Bone loss due to osteolysis may be further complicated by acetabular extraction. Cementation of a new UHMWPE non constrained liner offers a less extensive surgery during which bone defects can be filled with bone graft or bone substitutes to restore bone stock. An 88% 11 year survival rate would be excellent for this kind of revision surgery; 80% would still be a very good result. Some potential weaknesses became apparent during this study. Several classifications were devised to deal with periacetabular osteolysis and bone loss. Most of these rely on plain radiographs and are based on the region of bone loss and migration of the acetabular component. These classification systems provide surgeons with guidance in choice of implants, graft and fixation methods and liner exchange is not an option. However, our study deals with a condition similar to Paprosky type I in which there is only bone loss and no cup migration [4]. We found no classification or radiological study that correlates between the degree of bone loss and long term stability of a well fixed acetabular component. Therefore, we could only rely on clinical judgment pre-operatively and intraoperatively in the decision to keep a well fixed acetabular component. We conclude that in cases of osteolysis around a modular metal backed acetabular cup, a liner revision is a very good option although a relatively high dislocation rate should be considered. The inability to use a matching liner with a locking mechanism should not deter the surgeon and the use of cement will result in a lasting and stable mechanical complex.
References 1. Troelsen A, Malchau E, Sillesen N, et al. A review of current fixation use and registry outcomes in total hip arthroplasty: the uncemented paradox. Clin Orthop Relat Res 2013;471:2052.
G. Rivkin et al. / The Journal of Arthroplasty 30 (2015) 1041–1043 2. Beaule PE, Ebramzadeh E, Le Duff M, et al. Cementing a liner into a stable cementless acetabular shell: the double-socket technique. J Bone Joint Surg Am 2004;86-A:929. 3. Kandel L, Rivkin G, Friedman A, et al. Polyethylene liner cementation technique in asymptomatic versus symptomatic osteolysis. Orthopedics 2009;32:560. 4. Paprosky WG, Perona BG, Lawrence JM. Acetabular defect classification and surgical reconstruction in revision arthroplasty, a 6 year follow up evaluation. J Arthroplasty 1994;9:33. 5. Olerud S, Karlstrom G. Recurrent dislocation after total hip replacement. Treatment by fixing an additional sector to the acetabular component. J Bone Joint Surg (Br) 1985;67:402. 6. Barrack RL. Modularity of prosthetic implants. J Am Acad Orthop Surg 1994;2:16. 7. Della Valle CJ, Berger RA, Shott S, et al. Primary total hip arthroplasty with a porouscoated acetabular component. A concise follow-up of a previous report. J Bone Joint Surg Am 2004;86-A:1217.
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8. Berry DJ. Management of osteolysis around total hip arthroplasty. Orthopedics 1999; 22:805. 9. Beaule PE, Campbell P, Mirra J, et al. Osteolysis in a cementless, second generation metal-on-metal hip replacement. Clin Orthop Relat Res 2001:159. 10. Terefenko KM, Sychterz CJ, Orishimo K, et al. Polyethylene liner exchange for excessive wear and osteolysis. J Arthroplasty 2002;17:798. 11. Haft GF, Jeiner AD, Callaghan JJ, et al. Polyethylene liner cementation into fixed acetabular shells. J Arthroplasty 2002;17:167. 12. Bonner KF, Delanois RE, Harbach G, et al. Cementation of a polyethylene liner into a metal shell. Factors related to mechanical stability. J Bone Joint Surg Am 2002;84-A: 1587. 13. Callaghan JJ, Hennessy DW, Liu SS, et al. Cementing acetabular liners into secure cementless shells for polyethylene wear provides durable mid-term fixation. Clin Orthop Relat Res 2012;470(11):3142.