Clinical & Radiographic Outcomes of Cemented vs. Diaphyseal Engaging Cementless Stems in Aseptic Revision TKA Jeremy M. Gililland MD, Christian J. Gaffney MD, Susan Odum PhD, Thomas Fehring MD, Christopher Peters MD, Walter Beaver MD PII: DOI: Reference:
S0883-5403(14)00337-4 doi: 10.1016/j.arth.2014.03.049 YARTH 53992
To appear in:
Journal of Arthroplasty
Received date: Revised date: Accepted date:
17 August 2013 28 February 2014 14 March 2014
Please cite this article as: Gililland Jeremy M., Gaffney Christian J., Odum Susan, Fehring Thomas, Peters Christopher, Beaver Walter, Clinical & Radiographic Outcomes of Cemented vs. Diaphyseal Engaging Cementless Stems in Aseptic Revision TKA, Journal of Arthroplasty (2014), doi: 10.1016/j.arth.2014.03.049
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT Clinical & Radiographic Outcomes of Cemented vs. Diaphyseal Engaging Cementless Stems in Aseptic Revision TKA
T
Jeremy M Gililland MD1, Christian J Gaffney MD1, Susan Odum PhD2, Thomas Fehring MD2, Christopher Peters MD1, Walter Beaver MD2
SC NU
AC
CE
PT
ED
MA
(2) OrthoCarolina Hip & Knee Center 2001 Vail Avenue Charlotte, NC, USA 28207
RI P
(1) University of Utah School of Medicine Department of Orthopaedic Surgery 590 Wakara Way Salt Lake City, UT, USA 84108
Each author certifies that his or her institution approved the human protocol for this investigation and that all investigations were conducted in conformity with ethical principles of research. Jeremy M. Gililland, MD (corresponding author) Assistant Professor University of Utah School of Medicine Department of Orthopaedic Surgery 590 Wakara Way, Salt Lake City, UT 84108, USA e-mail: [email protected] phone: 801-664-2080
ACCEPTED MANUSCRIPT
Abstract:
T
The rate of revision TKA will continue to increase. Although modular revision systems have
RI P
become standard, the type of stem fixation remains controversial. The purpose of this study is to compare the incidence of failure between cemented and diaphyseal engaging cementless stems in
SC
aseptic revision TKAs. We performed a multicenter retrospective clinical and radiographic
NU
review of 82 revision TKAs performed for aseptic failures of primary TKAs. Follow-up averaged 76 months and 121 months for the cemented and cementless groups respectively. Re-
MA
revision rates and radiographic failure rates for both femoral and tibial stems were similar between groups. Additionally, we found similar improvements in knee society scores between
ED
the groups. At midterm follow-up, we found no difference in failure rates of cemented and diaphyseal engaging cementless stems. Both types of stem appear to provide reliable fixation and
AC
CE
PT
are viable options in the revision total knee arthroplasty setting.
ACCEPTED MANUSCRIPT
Introduction:
T
As the number of middle aged and elderly individuals in the United States continues to rise, so
RI P
will the demand for primary total knee arthroplasty (TKA). Following this rise in primary TKA will come a subsequent rise in revision surgery, and this is projected to grow to 250,000 revision
SC
TKAs, by 2030. [1] The reasons for revision are many and include aseptic loosening, infection,
NU
periprosthetic fracture, instability, malalignment, and component failure.
Obtaining consistent alignment and fixation during revision surgery is challenging for several
MA
reasons: loss of bony landmarks, decreased bone stock, and poor bone quality. As a result stems are often used in revision TKA to provide improved fixation and alignment. Stems also improve
ED
rotational stability, allow for bypass of structural defects, and reduce stresses at the bone implant
PT
interface. There is currently debate as to the ideal method of stem fixation within the femoral and tibial canals, whether it is cemented or the “hybrid” technique of a press-fit cementless stem and a
CE
surface cemented femoral/tibial component. Excellent midterm results have been shown for both cementless and cemented stem revision TKA constructs in a number of published series.[2-9]
AC
However, very few studies exist comparing cementless and cemented stem constructs in revision TKA.[10, 11]
The purpose of this study was to answer the following questions: (1) Are re-revision rates for aseptic loosening comparable between cemented stems and hybrid cementless stems in revision TKAs performed for aseptic failures? (2) Are there any differences in the modified Knee Society radiographic scores between these two stem techniques in aseptic revisions? (3) Are there any differences in the clinical outcomes between these two stem techniques in aseptic revisions? Our hypothesis was that there would be no difference in any of these variables between these two methods of stem fixation.
ACCEPTED MANUSCRIPT
Methods:
T
We performed a retrospective analysis of data collected prospectively from two centers
RI P
(OrthoCarolina Hip and Knee Center Charlotte, NC, USA [OC], and the University of Utah, Salt Lake City, UT, USA [UoU]). Traditionally, the majority of revision TKAs have been performed
SC
using cementless stems at the UoU, unlike OC, where most revision TKAs have been done using cemented stems. Therefore, we decided to utilize the UoU registry to obtain our cementless stem
NU
cohort, while we obtained our cemented stem cohort from the OC registry. We included patients who underwent a revision TKA utilizing femoral, tibial, or both stemmed components from a
MA
prior primary TKA for reasons other than septic failure between 1991 and 2010, and who had adequate follow-up, defined as 2-year minimum AP/lateral radiographs and clinical follow-up or
ED
who had failed prior to two years. As it has been previously demonstrated by Fehring that
PT
metaphyseal cementless stems have higher failure rates in the revision TKA setting, we elected to exclude any revision TKA with cementless stems that did not engage the diaphysis for at least
CE
4cm.[11] Between 1991 and 2010, a total of 2,064 revision TKAs were performed at both centers. Of these 2,064 revision TKAs, a total of 1,344 were performed for aseptic failure reasons. From
AC
this population of 1,344 aseptic revision TKAs, we selected the study sample of 189 patients who met the study eligibility criteria described above. Subsequently, 82 revision TKAs in 81 (43%) patients with complete and adequate follow up data were included in the analysis. Forty-nine of these revisions utilized cemented stems and 33 utilized diaphyseal engaging cementless stems, with a total of 82 femoral and 78 tibial stems available for review.
For cemented stem revisions, intramedullary canal cement restrictors were placed in the femur and tibia. A cement gun was then used to retrograde fill and pressurize the canal before insertion of the stemmed implant. Cement was placed along the dried, bony cut surfaces as well as being placed on the undersurface and metaphyseal portion (stem/coupler interface) of the implant.
ACCEPTED MANUSCRIPT Antibiotic-impregnated cement was routinely used for both cemented and cementless reconstructions. Cement type was based on surgeon preference and not recorded in this study.
T
The length of cemented stem utilized was surgeon dependent, and we did not exclude patients
RI P
with metaphyseal-cemented stems for this study.
SC
The hybrid cementless revision technique consisted of aggressive intramedullary reaming of the femur and tibia until good cortical contact was achieved. Cement was placed on the clean, dried,
NU
cut bony surface and along the undersurface and metaphyseal portion (stem/coupler interface) of the tibial and femoral implant. Cement was not placed into the diaphysis. The appropriate stem
MA
length was chosen by the level of cortical engagement; the stem implant chosen required at least a 4-cm diaphyseal press-fit. A variety of implants were used for reconstruction and the decision on
ED
implant type was surgeon-dependent. We did not record implant manufacturer data, stem length,
PT
stem diameter or use of stem offset.
CE
Radiographic evaluations were performed by two independent surgeons (JMG, CJG). Modification of the Knee Society scores for radiographic analyses was performed for all stems
AC
according to the system described by Fehring et al.[11] According to this system, femoral and tibial components were defined as stable, closely observe, or loose by the number and width of radiolucencies present. First, the width of radiolucent lines for each zone in millimeters surrounding the femoral and tibial component in the AP and lateral plane is recorded. Then, the total width for each zone is added and a numeric score is generated for each component. Femoral components with radiolucencies ≤ 8 = stable, 9 to 19 = closely observe, and ≥ 20 = loose. Tibial components with radiolucencies ≤ 9 = stable, 10 to 22 = closely observe, and ≥ 23 = loose. For this study, stems were considered radiographically loose if they were classified as either “closely observe” or “loose”. Reviewing the cortical thickness and remaining amount of cortical bone stock on both the AP and lateral plain radiographs allowed us to subjectively assess bone quality
ACCEPTED MANUSCRIPT as described by Edwards et al.[10] Bone quality was then recorded, using a subjective grading scale, as follows for both the femur and tibia: good cortex on both AP and lateral radiographs,
T
good cortex on either AP or lateral radiographs, or poor cortex on both AP and lateral
RI P
radiographs. We did not record the femoral or tibial bone loss associated with reconstruction, but we did review the operative records for all cases and recorded use of tibial and/or femoral
SC
augments, wedges, sleeves, or cones. Medical records were reviewed for any subsequent rerevision of these revision TKAs. Clinical outcomes were evaluated using the Knee Society Score
NU
(KSS). KSS were prospectively collected as routine practice at both centers. The KSS at the University of Utah were completed by attending surgeons, fellows and residents. At
MA
OrthoCarolina, KSS were completed by attending surgeons and fellows. Failure was defined as
ED
aseptic revision of the stemmed components or radiographic evidence of loosening.
PT
Patients in the cemented and cementless groups averaged 65 and 64 years of age respectively (p=0.65). The stem groups were also similar with respect to sex (p=0.19). Of the 49 patients with
CE
a cemented stem, there were 24 males (49%) and 25 females (51%). Of the 32 patients with cementless stems, there were 11 males (34%) and 21 females (66%). Follow-up averaged 96
AC
months for the entire group (range 26-250). The mean follow-up was 76 months (range 26-245) and 121 months (range 74-250) for the cemented and cementless groups respectively (p0.99). This resulted in aseptic re-revision rates of 4% and 6% for the cemented and cementless femoral-stemmed components respectively. Of these re-revisions, two patients
MA
account for both the cemented stem re-revisions of the tibia and femoral cemented stems. One of these re-revisions was done for a diagnosis of instability and was revised to a hinge at 6 years
ED
after the initial revision surgery. The other re-revision was for femoral component loosening and
PT
was also converted to a hinge 7 years after the initial revision. One patient with a cementless stem underwent re-revision of both the tibial and femoral stems due to femoral component malrotation
CE
and instability and was converted to a hinge 11 months after the initial revision surgery. Finally, one patient in the cementless stem group had an isolated re-revision of the femoral stem
AC
secondary to periprosthetic fracture and was re-revised 6 months after the initial revision surgery. Reoperations overall were also found to be similar between the groups.
There were similar radiographic outcomes in the cemented stem group compared with the cementless stem group (Table 1). More specifically, the data demonstrated no difference in the amount of radiographic loosening for the femoral stems (p >0.99) or the tibial stems (p=0.55) One patient in the cementless group that was classified as “closely observe” subsequently required re-revision. There was no difference between the stems in regards to radiographic evidence of migration (p=0.41 femoral, p>0.99 tibial), subsidence (p=0.38 femoral, p=0.36 tibial) or windshield wipering (p=0.41 femoral, p=0.41 tibial). We found a similar distribution of
ACCEPTED MANUSCRIPT radiographic poor bone quality between the groups (p=0.07). Of the 69 stems implanted in good bone cortex (good on both AP and lateral view or good on either the AP or lateral view), 2 stems
T
(1 cemented and 1 cementless, p>0.99) (3%) were considered radiographically loose, whereas 3
RI P
(2 cemented and 1 cementless, p=0.33) (33%) of the 9 stems utilized in poor-quality bone were radiographically loose (p = 0.01). Combining the re-revision failures and those deemed
SC
radiographically loose resulted in a failure rate for the tibial components of 6% for cemented
9% of the cementless stems failed (p
S0883-5403(14)00337-4 doi: 10.1016/j.arth.2014.03.049 YARTH 53992
To appear in:
Journal of Arthroplasty
Received date: Revised date: Accepted date:
17 August 2013 28 February 2014 14 March 2014
Please cite this article as: Gililland Jeremy M., Gaffney Christian J., Odum Susan, Fehring Thomas, Peters Christopher, Beaver Walter, Clinical & Radiographic Outcomes of Cemented vs. Diaphyseal Engaging Cementless Stems in Aseptic Revision TKA, Journal of Arthroplasty (2014), doi: 10.1016/j.arth.2014.03.049
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT Clinical & Radiographic Outcomes of Cemented vs. Diaphyseal Engaging Cementless Stems in Aseptic Revision TKA
T
Jeremy M Gililland MD1, Christian J Gaffney MD1, Susan Odum PhD2, Thomas Fehring MD2, Christopher Peters MD1, Walter Beaver MD2
SC NU
AC
CE
PT
ED
MA
(2) OrthoCarolina Hip & Knee Center 2001 Vail Avenue Charlotte, NC, USA 28207
RI P
(1) University of Utah School of Medicine Department of Orthopaedic Surgery 590 Wakara Way Salt Lake City, UT, USA 84108
Each author certifies that his or her institution approved the human protocol for this investigation and that all investigations were conducted in conformity with ethical principles of research. Jeremy M. Gililland, MD (corresponding author) Assistant Professor University of Utah School of Medicine Department of Orthopaedic Surgery 590 Wakara Way, Salt Lake City, UT 84108, USA e-mail: [email protected] phone: 801-664-2080
ACCEPTED MANUSCRIPT
Abstract:
T
The rate of revision TKA will continue to increase. Although modular revision systems have
RI P
become standard, the type of stem fixation remains controversial. The purpose of this study is to compare the incidence of failure between cemented and diaphyseal engaging cementless stems in
SC
aseptic revision TKAs. We performed a multicenter retrospective clinical and radiographic
NU
review of 82 revision TKAs performed for aseptic failures of primary TKAs. Follow-up averaged 76 months and 121 months for the cemented and cementless groups respectively. Re-
MA
revision rates and radiographic failure rates for both femoral and tibial stems were similar between groups. Additionally, we found similar improvements in knee society scores between
ED
the groups. At midterm follow-up, we found no difference in failure rates of cemented and diaphyseal engaging cementless stems. Both types of stem appear to provide reliable fixation and
AC
CE
PT
are viable options in the revision total knee arthroplasty setting.
ACCEPTED MANUSCRIPT
Introduction:
T
As the number of middle aged and elderly individuals in the United States continues to rise, so
RI P
will the demand for primary total knee arthroplasty (TKA). Following this rise in primary TKA will come a subsequent rise in revision surgery, and this is projected to grow to 250,000 revision
SC
TKAs, by 2030. [1] The reasons for revision are many and include aseptic loosening, infection,
NU
periprosthetic fracture, instability, malalignment, and component failure.
Obtaining consistent alignment and fixation during revision surgery is challenging for several
MA
reasons: loss of bony landmarks, decreased bone stock, and poor bone quality. As a result stems are often used in revision TKA to provide improved fixation and alignment. Stems also improve
ED
rotational stability, allow for bypass of structural defects, and reduce stresses at the bone implant
PT
interface. There is currently debate as to the ideal method of stem fixation within the femoral and tibial canals, whether it is cemented or the “hybrid” technique of a press-fit cementless stem and a
CE
surface cemented femoral/tibial component. Excellent midterm results have been shown for both cementless and cemented stem revision TKA constructs in a number of published series.[2-9]
AC
However, very few studies exist comparing cementless and cemented stem constructs in revision TKA.[10, 11]
The purpose of this study was to answer the following questions: (1) Are re-revision rates for aseptic loosening comparable between cemented stems and hybrid cementless stems in revision TKAs performed for aseptic failures? (2) Are there any differences in the modified Knee Society radiographic scores between these two stem techniques in aseptic revisions? (3) Are there any differences in the clinical outcomes between these two stem techniques in aseptic revisions? Our hypothesis was that there would be no difference in any of these variables between these two methods of stem fixation.
ACCEPTED MANUSCRIPT
Methods:
T
We performed a retrospective analysis of data collected prospectively from two centers
RI P
(OrthoCarolina Hip and Knee Center Charlotte, NC, USA [OC], and the University of Utah, Salt Lake City, UT, USA [UoU]). Traditionally, the majority of revision TKAs have been performed
SC
using cementless stems at the UoU, unlike OC, where most revision TKAs have been done using cemented stems. Therefore, we decided to utilize the UoU registry to obtain our cementless stem
NU
cohort, while we obtained our cemented stem cohort from the OC registry. We included patients who underwent a revision TKA utilizing femoral, tibial, or both stemmed components from a
MA
prior primary TKA for reasons other than septic failure between 1991 and 2010, and who had adequate follow-up, defined as 2-year minimum AP/lateral radiographs and clinical follow-up or
ED
who had failed prior to two years. As it has been previously demonstrated by Fehring that
PT
metaphyseal cementless stems have higher failure rates in the revision TKA setting, we elected to exclude any revision TKA with cementless stems that did not engage the diaphysis for at least
CE
4cm.[11] Between 1991 and 2010, a total of 2,064 revision TKAs were performed at both centers. Of these 2,064 revision TKAs, a total of 1,344 were performed for aseptic failure reasons. From
AC
this population of 1,344 aseptic revision TKAs, we selected the study sample of 189 patients who met the study eligibility criteria described above. Subsequently, 82 revision TKAs in 81 (43%) patients with complete and adequate follow up data were included in the analysis. Forty-nine of these revisions utilized cemented stems and 33 utilized diaphyseal engaging cementless stems, with a total of 82 femoral and 78 tibial stems available for review.
For cemented stem revisions, intramedullary canal cement restrictors were placed in the femur and tibia. A cement gun was then used to retrograde fill and pressurize the canal before insertion of the stemmed implant. Cement was placed along the dried, bony cut surfaces as well as being placed on the undersurface and metaphyseal portion (stem/coupler interface) of the implant.
ACCEPTED MANUSCRIPT Antibiotic-impregnated cement was routinely used for both cemented and cementless reconstructions. Cement type was based on surgeon preference and not recorded in this study.
T
The length of cemented stem utilized was surgeon dependent, and we did not exclude patients
RI P
with metaphyseal-cemented stems for this study.
SC
The hybrid cementless revision technique consisted of aggressive intramedullary reaming of the femur and tibia until good cortical contact was achieved. Cement was placed on the clean, dried,
NU
cut bony surface and along the undersurface and metaphyseal portion (stem/coupler interface) of the tibial and femoral implant. Cement was not placed into the diaphysis. The appropriate stem
MA
length was chosen by the level of cortical engagement; the stem implant chosen required at least a 4-cm diaphyseal press-fit. A variety of implants were used for reconstruction and the decision on
ED
implant type was surgeon-dependent. We did not record implant manufacturer data, stem length,
PT
stem diameter or use of stem offset.
CE
Radiographic evaluations were performed by two independent surgeons (JMG, CJG). Modification of the Knee Society scores for radiographic analyses was performed for all stems
AC
according to the system described by Fehring et al.[11] According to this system, femoral and tibial components were defined as stable, closely observe, or loose by the number and width of radiolucencies present. First, the width of radiolucent lines for each zone in millimeters surrounding the femoral and tibial component in the AP and lateral plane is recorded. Then, the total width for each zone is added and a numeric score is generated for each component. Femoral components with radiolucencies ≤ 8 = stable, 9 to 19 = closely observe, and ≥ 20 = loose. Tibial components with radiolucencies ≤ 9 = stable, 10 to 22 = closely observe, and ≥ 23 = loose. For this study, stems were considered radiographically loose if they were classified as either “closely observe” or “loose”. Reviewing the cortical thickness and remaining amount of cortical bone stock on both the AP and lateral plain radiographs allowed us to subjectively assess bone quality
ACCEPTED MANUSCRIPT as described by Edwards et al.[10] Bone quality was then recorded, using a subjective grading scale, as follows for both the femur and tibia: good cortex on both AP and lateral radiographs,
T
good cortex on either AP or lateral radiographs, or poor cortex on both AP and lateral
RI P
radiographs. We did not record the femoral or tibial bone loss associated with reconstruction, but we did review the operative records for all cases and recorded use of tibial and/or femoral
SC
augments, wedges, sleeves, or cones. Medical records were reviewed for any subsequent rerevision of these revision TKAs. Clinical outcomes were evaluated using the Knee Society Score
NU
(KSS). KSS were prospectively collected as routine practice at both centers. The KSS at the University of Utah were completed by attending surgeons, fellows and residents. At
MA
OrthoCarolina, KSS were completed by attending surgeons and fellows. Failure was defined as
ED
aseptic revision of the stemmed components or radiographic evidence of loosening.
PT
Patients in the cemented and cementless groups averaged 65 and 64 years of age respectively (p=0.65). The stem groups were also similar with respect to sex (p=0.19). Of the 49 patients with
CE
a cemented stem, there were 24 males (49%) and 25 females (51%). Of the 32 patients with cementless stems, there were 11 males (34%) and 21 females (66%). Follow-up averaged 96
AC
months for the entire group (range 26-250). The mean follow-up was 76 months (range 26-245) and 121 months (range 74-250) for the cemented and cementless groups respectively (p0.99). This resulted in aseptic re-revision rates of 4% and 6% for the cemented and cementless femoral-stemmed components respectively. Of these re-revisions, two patients
MA
account for both the cemented stem re-revisions of the tibia and femoral cemented stems. One of these re-revisions was done for a diagnosis of instability and was revised to a hinge at 6 years
ED
after the initial revision surgery. The other re-revision was for femoral component loosening and
PT
was also converted to a hinge 7 years after the initial revision. One patient with a cementless stem underwent re-revision of both the tibial and femoral stems due to femoral component malrotation
CE
and instability and was converted to a hinge 11 months after the initial revision surgery. Finally, one patient in the cementless stem group had an isolated re-revision of the femoral stem
AC
secondary to periprosthetic fracture and was re-revised 6 months after the initial revision surgery. Reoperations overall were also found to be similar between the groups.
There were similar radiographic outcomes in the cemented stem group compared with the cementless stem group (Table 1). More specifically, the data demonstrated no difference in the amount of radiographic loosening for the femoral stems (p >0.99) or the tibial stems (p=0.55) One patient in the cementless group that was classified as “closely observe” subsequently required re-revision. There was no difference between the stems in regards to radiographic evidence of migration (p=0.41 femoral, p>0.99 tibial), subsidence (p=0.38 femoral, p=0.36 tibial) or windshield wipering (p=0.41 femoral, p=0.41 tibial). We found a similar distribution of
ACCEPTED MANUSCRIPT radiographic poor bone quality between the groups (p=0.07). Of the 69 stems implanted in good bone cortex (good on both AP and lateral view or good on either the AP or lateral view), 2 stems
T
(1 cemented and 1 cementless, p>0.99) (3%) were considered radiographically loose, whereas 3
RI P
(2 cemented and 1 cementless, p=0.33) (33%) of the 9 stems utilized in poor-quality bone were radiographically loose (p = 0.01). Combining the re-revision failures and those deemed
SC
radiographically loose resulted in a failure rate for the tibial components of 6% for cemented
9% of the cementless stems failed (p
