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Isolated Patellofemoral Joint Arthroplasty: Can Preoperative Bone Scans Predict Survivorship?
The Journal of Arthroplasty xxx (2019) 1e4
Contents lists available at ScienceDirect
The Journal of Arthroplasty journal homepage: www.arthroplastyjournal.org
Isolated Patellofemoral Joint Arthroplasty: Can Preoperative Bone Scans Predict Survivorship? James F. Baker, MD a, David N. Caborn, MD a, Thomas J. Schlierf, MD a, Trevor B. Fain, BS b, Langan S. Smith, BS c, Arthur L. Malkani, MD a, * a b c
Department of Orthopaedic Surgery, University of Louisville, Louisville, KY School of Medicine, University of Louisville, Louisville, KY Orthopedic Associates, KentuckyOne Health Medical Group, Louisville, KY
a r t i c l e i n f o
a b s t r a c t
Article history: Received 27 May 2019 Received in revised form 22 July 2019 Accepted 8 August 2019 Available online xxx
Background: Isolated patellofemoral joint arthritis has been identified in 10% of the population presenting with symptomatic knee osteoarthritis. Patient selection is important in order to improve survivorship following PF arthroplasty. The purpose of this study is to compare the use of a preoperative bone scan vs a magnetic resonance imaging (MRI) to identify the patient with isolated PF arthritis. Methods: This is a retrospective review of 32 patients undergoing isolated PF arthroplasty for PF arthritis using the same implant design. Sixteen consecutive patients received a preoperative bone scan to confirm isolated PF arthritis. These patients were matched by age and gender to patients where an MRI was used to determine isolated PF arthritis. The bone scan cohort contained 13 females and three males with an average age of 48 years and average follow-up of 52 months. There was no significant difference in age, body mass index, follow-up, or preoperative range of motion between the groups. The MRI and bone scan results were reported by a radiologist specializing in orthopedic radiology. Results: Survivorship was 100% in the PF arthroplasty group selected using a preoperative bone scan. Revision surgery with conversion to TKA was required in 5 of 16 patients (31%) when an MRI was used to identify isolated PF arthritis. Revision in all patients in the MRI group was due to progression of knee arthritis in the tibial-femoral joint. There were no cases of implant-related failures. Conclusion: Patellofemoral arthroplasty using a modern design implant demonstrated 100% survivorship when a preoperative bone scan was used for patient selection to confirm isolated PF arthritis. In the group where only an MRI was used, there was a 31% failure due to progression of the disease. Based on this study, we would recommend the use of a bone scan as a tool in the selection criteria for patients undergoing PF arthroplasty. © 2019 Elsevier Inc. All rights reserved.
Keywords: patellofemoral joint arthritis patellofemoral arthroplasty bone scan MRI survivorship
Isolated patellofemoral joint (PFJ) osteoarthritis (OA) has been shown to occur in 15%-20% of patients over the age of 50 [1]. Studies have shown that PFJ OA also has a higher prevalence in females than males. The association between PFJ arthritis and pain along with function and global scores was demonstrated by Hunter et al [2]. There have been various treatment approaches to address isolated
One or more of the authors of this paper have disclosed potential or pertinent conflicts of interest, which may include receipt of payment, either direct or indirect, institutional support, or association with an entity in the biomedical field which may be perceived to have potential conflict of interest with this work. For full disclosure statements refer to https://doi.org/10.1016/j.arth.2019.08.021. * Reprint requests: Arthur L. Malkani, MD, Department of Orthopaedic Surgery, University of Louisville, Adult Reconstruction Program, 550 S. Jackson Street, 1st floor, ACB, Louisville, KY, 40202. https://doi.org/10.1016/j.arth.2019.08.021 0883-5403/© 2019 Elsevier Inc. All rights reserved.
patellofemoral arthroplasty (PFA) OA including both PFJ arthroplasty and total knee arthroplasty (TKA). Isolated PFA resulted in poor results during the 1980s with many surgeons instead proceeding with primary TKA [3,4]. Improvements have been made in implant design, surgical instruments, and technique; however, there are still reported failure rates of up to 20% [5]. The most frequent cause of failure of PFA leading to conversion to TKA is progression of the arthritis to involve the tibia-femoral joint. Up to 38% of failures were the result of progression of OA in a systemic review by Van Der List et al [6]. With a large percentage of PFA failures being due to the progression of OA, patient selection is an extremely important factor in determining PF implant survivorship. Williams et al [7] recommended obtaining preoperative magnetic resonance imaging (MRI) as a way of assessing the tibial-femoral compartment before proceeding with surgery. Other radiographic
2
J.F. Baker et al. / The Journal of Arthroplasty xxx (2019) 1e4
studies have also been investigated in determining what radiographic features correlate with advancement of OA [8]. Dieppe et al [9] demonstrated the ability of bone scintigraphy to be a good predictor of OA progression. The purpose of this study is to determine if a preoperative bone scan would be a better predictor of survivorship compared to an MRI in patients undergoing isolated PFA. Methods This is a retrospective review of 32 patients undergoing isolated PFA for PF arthritis at the same institution performed by one of the two surgeons and with the same current design patella-femoral implant (Gender Solutions PFJ; Zimmer, Warsaw, IN) between 2007 and 2015. Indications for patient selection undergoing a PFA by one of the surgeons included isolated radiographic PF arthritis and MRI confirming lack of tibial femoral disease. The second surgeon’s indications included isolated radiographic PF disease and a bone scan to confirm lack of early tibiofemoral arthritis. In 16 consecutive patients, a preoperative bone scan was obtained for patient selection to confirm isolated PF arthritis. These patients were matched by age and gender with 16 patients where an MRI was used as a preoperative tool to confirm isolated PF arthritis. All patients had a diagnosis of OA. Both MRI and 3-phase bone scans were reviewed by both the treating surgeon and a fellowship trained musculoskeletal radiologist. Increased uptake in the PFJ on 3-phase bone scan is indicative of PF arthritis (Figs. 1 and 2). MRI was performed using a 1.5 Tesla MRI. Bone scans were performed using 99mTc phosphates and a 3-phase protocol. Clinical outcomes along with radiographic analysis were evaluated including complications and survivorship. Standard clinical and radiographic follow-up occurred at 2 weeks, 6 weeks, 3 months, 1 year, 2 years, and 5 years. Statistical analysis was completed using Microsoft Excel (Microsoft Corp). Student’s t-test was used to determine any significant differences between the cohorts. Kaplan-Meier analysis was used to determine the survival in each cohort. Results There were 13 females and 3 males with an average age 48 years (33-60), an average body mass index of 33.8 (21.9-49.02), and a mean follow-up of 52 months (30-105) in the bone scan cohort (Table 1). Knee society function scores were 48.0 preoperatively and 65.7 at most recent follow-up. The MRI cohort consisted of 13 females and 3 males with an average age 48 years (37-61), an average BMI of 29.33 (21.6-38.4), and a mean follow up of 63
months (38-115). Knee society function scores were 49.6 preoperatively and 70.64 at most recent follow-up. There was no significant difference in functional outcomes (P ¼ .04). Revision surgery was required in 0 of 16 patients (0% revision rate) who received a bone scan. Revision surgery was required in 5 of 16 patients (31% revision rate) where an MRI was used to assist in the decision making to identify isolated PF arthritis. The primary reason for revision in all patients was progression of arthritis in the tibial-femoral joint leading to TKA. There were no cases of implant-related failures due to aseptic loosening or maltracking in either group. Survivorship in the MRI cohort was 69% at 5 years. Using Kaplan-Meier analysis the mean survival of those patients undergoing preoperative MRI was 6.19 years (95% confidence interval 4.27-8.12) (Fig. 3). Discussion Although TKA has long been considered the “gold standard” treatment for severe knee arthritis of any compartment, isolated PFA has certain potential advantages. Isolated PFA preserves the patient’s native anatomy of the medial and lateral compartments along with the anterior and posterior cruciate ligaments and menisci which help maintain normal knee kinematics. PFA has also been recognized as a less invasive operation than TKA allowing for a more rapid recovery [10,11]. Dahm et al [12] demonstrated that PFA has comparable clinical outcomes to TKA but with less blood loss and a shorter hospital stay. Tarassoli et al [13] noted in a systematic review that PFA has the advantage of being a less invasive operation, with quicker postoperative recovery and preservation of bone stock, with the option to convert to TKA at a later time. Despite the potential advantages of isolated PFA, the initial results of the first-generation PFA implants were not favorable, with high failure rates primarily due to mechanical failure [14e17]. McKeever originally proposed a design allowing for a Vitallium shell to replace the patella surface [13,18]. This design eventually lost favor due to concerns of the accelerated wear of the femoral trochlea cartilage. In 1979, Lubinus et al and Blazina et al reported on the first two designs for total PFA systems, the Lubinus Glide (Link, Hamburg, Germany) and Richards Mod I and II systems (Smith Nephew Richards, Memphis, TN) [19,20]. These systems had survivorship results that ranged from 45% to 88% at short and midterm follow-up [14e17,21]. A high incidence of secondary surgery was necessary for correction of patellar instability and mechanical problems, such as the patella catching on the edges of the trochlear component. These problems have been associated with trochlear design features that put the patella at risk for maltracking
Fig. 1. (A) Anteroposterior bone scan image of a 45-year-old female with increased uptake predominantly within the patellofemoral compartment of the right knee who underwent PFA. (B) Lateral bone scan image depicting increased isolated patellofemoral uptake.
J.F. Baker et al. / The Journal of Arthroplasty xxx (2019) 1e4
3
Fig. 2. (A) Lateral 3-phase bone scan in a 59-year-old female demonstrating increased uptake in the PF joint and medial compartment, who was not a candidate for a PF arthroplasty. (B) Anteroposterior bone scan image depicting increased uptake in both PF and medial compartment of the right knee.
[21]. The deep, constraining trochlear groove of the Richards Mod I and II implants predisposed to subtle maltracking and catching of the implant on the trochlear edges. The Lubinus patellofemoral implant has been reported to have a high rate of reoperation for patellofemoral dysfunction [17]. In 2001, Tauro et al [17] reported the need for revision surgery in 28% of knees with the Lubinus prosthesis, primarily for patellar maltracking, with 32% of cases in the series having trochlear malalignment or patellar maltracking. Lonner et al [21] reported the incidence of patellofemoral dysfunction, subluxation, catching, and substantial pain to be 17% with the Lubinus prosthesis. Second-generation implants, such as the LCS mobile bearing (DePuy, Warsaw, IN), Autocentric (DePuy), and Avon (Stryker, Mahwah, NJ) have had greater short and midterm success. Reported success rates have ranged from 80% to 94% [22]. These next-generation PF implants have had higher success rates secondary to an improved trochlear design that reduced the incidence of patella maltracking. The Zimmer Gender Solutions PFJ system used in this study is an asymmetric design that takes into consideration that the vast majority of PFA recipients are women. It has done this by increasing its trochlear groove angle to accommodate the higher Q angle typical of female patients in all except its largest size. This design feature enhanced patellar femoral tracking and minimized the need for lateral release during the procedure [23]. The amount of surface contact between the patellar component and native cartilage has been reduced by extending the proximal extent of the trochlear component and refining the transitional point between the anterior trochlear flange and the intercondylar portion. Additionally, shorting the intercondylar tail has reduced impingement on the
proximal pole of the patellar component. The patellar component is a typical all-polyethylene modified dome that can be retained if a revision to a TKA is required for disease progression. The instruments were also designed for simplicity and accuracy [23]. A recent meta-analysis demonstrated there is no statistically significant difference between second-generation PFA and TKA in the development of mechanical complications, persistent pain after surgery, reoperation rate, or revision arthroplasty [24]. PFA is a viable treatment option for patients with isolated PF arthritis. These results are in accordance with our study findings of no mechanically related failures necessitating revision surgery. A 2012 meta-analysis by Dy et al [24] showed that about 30% of PFA revisions are due to the progression of OA. Leadbetter et al [25] also showed a similar rate of revision due to progression of OA. A study by Nicol et al [26] showed that when using a secondgeneration PFA system, progression of tibia-femoral arthritis was the etiology leading to revision in 86% of patients. Our data along with that of prior meta-analysis studies underscore the need to develop strict patient selection criteria to further improve survivorship in patients undergoing isolated PFA. Progression of underlying arthritis is the main etiology leading to failure of PFA with subsequent revision to TKA. Dieppe et al [9] demonstrated that bone scan was able to predict the progression of OA in the knee. In their study of 94 patients, none of the 55 patients without abnormalities on entry examinations had evidence of progression of OA, resulting in a negative predictive value of 100% and a negative likelihood ratio (LR) of 0% [9]. In comparison,
Patellofemoral Joint Arthroplasty Survivorship with MRI preoperavely
Table 1 Patient Demographics.
Total number of cases Number of males Number of females Mean age at surgery Mean BMI Mean follow-up
Bone Scan Cohort
1
MRI Cohort
16
16
3
3
13
13
48.44, SD ¼ 7.2 (range 33-60) 33.80, SD ¼ 8.64 (range 21.9-49.02) 52.37 mo, SD ¼ 21.14 (range 29.9-104.5)
47.75, SD ¼ 6.77 (range 37-61) 29.33, SD ¼ 5.02 (range 21.6-38.4) 63.11 mo, SD ¼ 26.26 (range 38.0-115.4)
t-Test (P Value)
.7829 .0836 .2125
MRI, magnetic resonance imaging; BMI, body mass index; SD, standard deviation.
Survivorship Probability%
Demographics
0.8 0.6 0.4 0.2 0
0
1
2
3
4
5
6
7
8
9
Time in Years
Fig. 3. Patellofemoral joint arthroplasty survivorship with MRI preoperatively.
4
J.F. Baker et al. / The Journal of Arthroplasty xxx (2019) 1e4
a meta-analysis by Menashe et al [27] examining MRI prediction of OA progression reported a negative predictive value of 57% and a LR of 0.48. LRs below 0.1 provide strong evidence to rule out a diagnosis [28]. The above studies indicate that a negative bone scan can more reliably rule out the presence of OA than a negative MRI. Early stages of OA have been associated with increased subchondral bone turnover and therapies to decrease subchondral activity have been hypothesized to slow the progression of OA [29,30]. Bone scans detect this increased activity of the subchondral bone and thus increased periarticular activity on bone scan may suggest a more rapid progression of OA [9,29,30]. Our study also supports the ability of bone scans to predict OA progression, as no patient who had a negative bone scan and received a PFA required a revision due to progression of the disease. In our study, PFA using a modern implant design coupled with preoperative bone scan in patient selection demonstrated 100% survivorship. In those undergoing only preoperative MRI there was a 31% failure due to progression of OA. If the advantages of PFA can be paired with the durability of a TKA by coupling modern design and surgical methods with a reliable predictor for progression of OA, PFA may become the treatment of choice for isolated PFJ OA. Based on this study and the available literature, we would recommend the use of a preoperative bone scan as a helpful tool in the selection process for patients considering isolated PFA. References [1] Stefanik JJ, Niu J, Gross KD, Roemer FW, Guermazi A, Felson DT. Using magnetic resonance imaging to determine the compartmental prevalence of knee joint structural damage. Osteoarthr Cartil 2013;21:695e9. [2] Hunter DJ, March L, Sambrook PN. The association of cartilage volume with knee pain. Osteoarthr Cartil 2003;11:725e9. [3] Insall J, Tria AJ, Aglietti P. Resurfacing of the patella. J Bone Joint Surg Am 1980;62:933e6. [4] Mont MA, Haas S, Mullick T, Hungerford DS. Total knee arthroplasty for patellofemoral arthritis. J Bone Joint Surg Am 2002;84-a:1977e81. [5] Hoogervorst P, de Jong RJ, Hannink G, van Kampen A. A 21% conversion rate to total knee arthroplasty of a first-generation patellofemoral prosthesis at a mean follow-up of 9.7 years. Int Orthop 2015;39:1857e64. [6] van der List JP, Chawla H, Villa JC, Pearle AD. Why do patellofemoral arthroplasties fail today? A systematic review. Knee 2017;24:2e8. [7] Williams DP, Pandit HG, Athanasou NA, Murray DW, Gibbons CL. Early revisions of the Femoro-Patella Vialla joint replacement. Bone Joint J 2013;95-b:793e7. [8] Barr AJ, Campbell TM, Hopkinson D, Kingsbury SR, Bowes MA, Conaghan PG. A systematic review of the relationship between subchondral bone features, pain and structural pathology in peripheral joint osteoarthritis. Arthritis Res Ther 2015;17:228.
[9] Dieppe P, Cushnaghan J, Young P, Kirwan J. Prediction of the progression of joint space narrowing in osteoarthritis of the knee by bone scintigraphy. Ann Rheum Dis 1993;52:557e63. [10] Ackroyd CE, Chir B. Development and early results of a new patellofemoral arthroplasty. Clin Orthop Relat Res 2005:7e13. [11] Odumenya M, McGuinness K, Achten J, Parsons N, Spalding T, Costa M. The Warwick patellofemoral arthroplasty trial: a randomised clinical trial of total knee arthroplasty versus patellofemoral arthroplasty in patients with severe arthritis of the patellofemoral joint. BMC Musculoskelet Disord 2011;12:265. [12] Dahm DL, Al-Rayashi W, Dajani K, Shah JP, Levy BA, Stuart MJ. Patellofemoral arthroplasty versus total knee arthroplasty in patients with isolated patellofemoral osteoarthritis. Am J Orthop (Belle Mead NJ) 2010;39:487e91. [13] Tarassoli P, Punwar S, Khan W, Johnstone D. Patellofemoral arthroplasty: a systematic review of the literature. Open Orthop J 2012;6:340e7. [14] Arciero RA, Toomey HE. Patellofemoral arthroplasty. A three- to nine-year follow-up study. Clin Orthop Relat Res 1988:60e71. [15] Board TN, Mahmood A, Ryan WG, Banks AJ. The Lubinus patellofemoral arthroplasty: a series of 17 cases. Arch Orthop Trauma Surg 2004;124:285e7. [16] Krajca-Radcliffe JB, Coker TP. Patellofemoral arthroplasty. A 2- to 18-year followup study. Clin Orthop Relat Res 1996:143e51. [17] Tauro B, Ackroyd CE, Newman JH, Shah NA. The Lubinus patellofemoral arthroplasty. A five- to ten-year prospective study. J Bone Joint Surg Br 2001;83:696e701. [18] McKeever DC. Patellar prosthesis. J Bone Joint Surg Am 1955;37-a:1074e84. [19] Blazina ME, Fox JM, Del Pizzo W, Broukhim B, Ivey FM. Patellofemoral replacement. Clin Orthop Relat Res 1979:98e102. [20] Lubinus HH. Patella glide bearing total replacement. Orthopedics 1979;2: 119e27. [21] Lonner JH. Patellofemoral arthroplasty: pros, cons, and design considerations. Clin Orthop Relat Res 2004:158e65. [22] Ackroyd CE, Newman JH, Evans R, Eldridge JD, Joslin CC. The Avon patellofemoral arthroplasty: five-year survivorship and functional results. J Bone Joint Surg Br 2007;89:310e5. [23] Lonner JH. Patellofemoral arthroplasty: the impact of design on outcomes. Orthop Clin North Am 2008;39:347e54. vi. [24] Dy CJ, Franco N, Ma Y, Mazumdar M, McCarthy MM, Gonzalez Della Valle A. Complications after patello-femoral versus total knee replacement in the treatment of isolated patello-femoral osteoarthritis. A meta-analysis. Knee Surg Sports Traumatol Arthrosc 2012;20:2174e90. [25] Leadbetter WB, Ragland PS, Mont MA. The appropriate use of patellofemoral arthroplasty: an analysis of reported indications, contraindications, and failures. Clin Orthop Relat Res 2005:91e9. [26] Nicol SG, Loveridge JM, Weale AE, Ackroyd CE, Newman JH. Arthritis progression after patellofemoral joint replacement. Knee 2006;13:290e5. [27] Menashe L, Hirko K, Losina E, Kloppenburg M, Zhang W, Li L, Hunter DJ. The diagnostic performance of MRI in osteoarthritis: a systematic review and meta-analysis. Osteoarthr Cartil 2012;20:13e21. [28] Deeks JJ, Altman DG. Diagnostic tests 4: likelihood ratios. BMJ 2004;329: 168e9. [29] Radin EL, Rose RM. Role of subchondral bone in the initiation and progression of cartilage damage. Clin Orthop Relat Res 1986:34e40. [30] Castaneda S, Roman-Blas JA, Largo R, Herrero-Beaumont G. Subchondral bone as a key target for osteoarthritis treatment. Biochem Pharmacol 2012;83: 315e23.
Contents lists available at ScienceDirect
The Journal of Arthroplasty journal homepage: www.arthroplastyjournal.org
Isolated Patellofemoral Joint Arthroplasty: Can Preoperative Bone Scans Predict Survivorship? James F. Baker, MD a, David N. Caborn, MD a, Thomas J. Schlierf, MD a, Trevor B. Fain, BS b, Langan S. Smith, BS c, Arthur L. Malkani, MD a, * a b c
Department of Orthopaedic Surgery, University of Louisville, Louisville, KY School of Medicine, University of Louisville, Louisville, KY Orthopedic Associates, KentuckyOne Health Medical Group, Louisville, KY
a r t i c l e i n f o
a b s t r a c t
Article history: Received 27 May 2019 Received in revised form 22 July 2019 Accepted 8 August 2019 Available online xxx
Background: Isolated patellofemoral joint arthritis has been identified in 10% of the population presenting with symptomatic knee osteoarthritis. Patient selection is important in order to improve survivorship following PF arthroplasty. The purpose of this study is to compare the use of a preoperative bone scan vs a magnetic resonance imaging (MRI) to identify the patient with isolated PF arthritis. Methods: This is a retrospective review of 32 patients undergoing isolated PF arthroplasty for PF arthritis using the same implant design. Sixteen consecutive patients received a preoperative bone scan to confirm isolated PF arthritis. These patients were matched by age and gender to patients where an MRI was used to determine isolated PF arthritis. The bone scan cohort contained 13 females and three males with an average age of 48 years and average follow-up of 52 months. There was no significant difference in age, body mass index, follow-up, or preoperative range of motion between the groups. The MRI and bone scan results were reported by a radiologist specializing in orthopedic radiology. Results: Survivorship was 100% in the PF arthroplasty group selected using a preoperative bone scan. Revision surgery with conversion to TKA was required in 5 of 16 patients (31%) when an MRI was used to identify isolated PF arthritis. Revision in all patients in the MRI group was due to progression of knee arthritis in the tibial-femoral joint. There were no cases of implant-related failures. Conclusion: Patellofemoral arthroplasty using a modern design implant demonstrated 100% survivorship when a preoperative bone scan was used for patient selection to confirm isolated PF arthritis. In the group where only an MRI was used, there was a 31% failure due to progression of the disease. Based on this study, we would recommend the use of a bone scan as a tool in the selection criteria for patients undergoing PF arthroplasty. © 2019 Elsevier Inc. All rights reserved.
Keywords: patellofemoral joint arthritis patellofemoral arthroplasty bone scan MRI survivorship
Isolated patellofemoral joint (PFJ) osteoarthritis (OA) has been shown to occur in 15%-20% of patients over the age of 50 [1]. Studies have shown that PFJ OA also has a higher prevalence in females than males. The association between PFJ arthritis and pain along with function and global scores was demonstrated by Hunter et al [2]. There have been various treatment approaches to address isolated
One or more of the authors of this paper have disclosed potential or pertinent conflicts of interest, which may include receipt of payment, either direct or indirect, institutional support, or association with an entity in the biomedical field which may be perceived to have potential conflict of interest with this work. For full disclosure statements refer to https://doi.org/10.1016/j.arth.2019.08.021. * Reprint requests: Arthur L. Malkani, MD, Department of Orthopaedic Surgery, University of Louisville, Adult Reconstruction Program, 550 S. Jackson Street, 1st floor, ACB, Louisville, KY, 40202. https://doi.org/10.1016/j.arth.2019.08.021 0883-5403/© 2019 Elsevier Inc. All rights reserved.
patellofemoral arthroplasty (PFA) OA including both PFJ arthroplasty and total knee arthroplasty (TKA). Isolated PFA resulted in poor results during the 1980s with many surgeons instead proceeding with primary TKA [3,4]. Improvements have been made in implant design, surgical instruments, and technique; however, there are still reported failure rates of up to 20% [5]. The most frequent cause of failure of PFA leading to conversion to TKA is progression of the arthritis to involve the tibia-femoral joint. Up to 38% of failures were the result of progression of OA in a systemic review by Van Der List et al [6]. With a large percentage of PFA failures being due to the progression of OA, patient selection is an extremely important factor in determining PF implant survivorship. Williams et al [7] recommended obtaining preoperative magnetic resonance imaging (MRI) as a way of assessing the tibial-femoral compartment before proceeding with surgery. Other radiographic
2
J.F. Baker et al. / The Journal of Arthroplasty xxx (2019) 1e4
studies have also been investigated in determining what radiographic features correlate with advancement of OA [8]. Dieppe et al [9] demonstrated the ability of bone scintigraphy to be a good predictor of OA progression. The purpose of this study is to determine if a preoperative bone scan would be a better predictor of survivorship compared to an MRI in patients undergoing isolated PFA. Methods This is a retrospective review of 32 patients undergoing isolated PFA for PF arthritis at the same institution performed by one of the two surgeons and with the same current design patella-femoral implant (Gender Solutions PFJ; Zimmer, Warsaw, IN) between 2007 and 2015. Indications for patient selection undergoing a PFA by one of the surgeons included isolated radiographic PF arthritis and MRI confirming lack of tibial femoral disease. The second surgeon’s indications included isolated radiographic PF disease and a bone scan to confirm lack of early tibiofemoral arthritis. In 16 consecutive patients, a preoperative bone scan was obtained for patient selection to confirm isolated PF arthritis. These patients were matched by age and gender with 16 patients where an MRI was used as a preoperative tool to confirm isolated PF arthritis. All patients had a diagnosis of OA. Both MRI and 3-phase bone scans were reviewed by both the treating surgeon and a fellowship trained musculoskeletal radiologist. Increased uptake in the PFJ on 3-phase bone scan is indicative of PF arthritis (Figs. 1 and 2). MRI was performed using a 1.5 Tesla MRI. Bone scans were performed using 99mTc phosphates and a 3-phase protocol. Clinical outcomes along with radiographic analysis were evaluated including complications and survivorship. Standard clinical and radiographic follow-up occurred at 2 weeks, 6 weeks, 3 months, 1 year, 2 years, and 5 years. Statistical analysis was completed using Microsoft Excel (Microsoft Corp). Student’s t-test was used to determine any significant differences between the cohorts. Kaplan-Meier analysis was used to determine the survival in each cohort. Results There were 13 females and 3 males with an average age 48 years (33-60), an average body mass index of 33.8 (21.9-49.02), and a mean follow-up of 52 months (30-105) in the bone scan cohort (Table 1). Knee society function scores were 48.0 preoperatively and 65.7 at most recent follow-up. The MRI cohort consisted of 13 females and 3 males with an average age 48 years (37-61), an average BMI of 29.33 (21.6-38.4), and a mean follow up of 63
months (38-115). Knee society function scores were 49.6 preoperatively and 70.64 at most recent follow-up. There was no significant difference in functional outcomes (P ¼ .04). Revision surgery was required in 0 of 16 patients (0% revision rate) who received a bone scan. Revision surgery was required in 5 of 16 patients (31% revision rate) where an MRI was used to assist in the decision making to identify isolated PF arthritis. The primary reason for revision in all patients was progression of arthritis in the tibial-femoral joint leading to TKA. There were no cases of implant-related failures due to aseptic loosening or maltracking in either group. Survivorship in the MRI cohort was 69% at 5 years. Using Kaplan-Meier analysis the mean survival of those patients undergoing preoperative MRI was 6.19 years (95% confidence interval 4.27-8.12) (Fig. 3). Discussion Although TKA has long been considered the “gold standard” treatment for severe knee arthritis of any compartment, isolated PFA has certain potential advantages. Isolated PFA preserves the patient’s native anatomy of the medial and lateral compartments along with the anterior and posterior cruciate ligaments and menisci which help maintain normal knee kinematics. PFA has also been recognized as a less invasive operation than TKA allowing for a more rapid recovery [10,11]. Dahm et al [12] demonstrated that PFA has comparable clinical outcomes to TKA but with less blood loss and a shorter hospital stay. Tarassoli et al [13] noted in a systematic review that PFA has the advantage of being a less invasive operation, with quicker postoperative recovery and preservation of bone stock, with the option to convert to TKA at a later time. Despite the potential advantages of isolated PFA, the initial results of the first-generation PFA implants were not favorable, with high failure rates primarily due to mechanical failure [14e17]. McKeever originally proposed a design allowing for a Vitallium shell to replace the patella surface [13,18]. This design eventually lost favor due to concerns of the accelerated wear of the femoral trochlea cartilage. In 1979, Lubinus et al and Blazina et al reported on the first two designs for total PFA systems, the Lubinus Glide (Link, Hamburg, Germany) and Richards Mod I and II systems (Smith Nephew Richards, Memphis, TN) [19,20]. These systems had survivorship results that ranged from 45% to 88% at short and midterm follow-up [14e17,21]. A high incidence of secondary surgery was necessary for correction of patellar instability and mechanical problems, such as the patella catching on the edges of the trochlear component. These problems have been associated with trochlear design features that put the patella at risk for maltracking
Fig. 1. (A) Anteroposterior bone scan image of a 45-year-old female with increased uptake predominantly within the patellofemoral compartment of the right knee who underwent PFA. (B) Lateral bone scan image depicting increased isolated patellofemoral uptake.
J.F. Baker et al. / The Journal of Arthroplasty xxx (2019) 1e4
3
Fig. 2. (A) Lateral 3-phase bone scan in a 59-year-old female demonstrating increased uptake in the PF joint and medial compartment, who was not a candidate for a PF arthroplasty. (B) Anteroposterior bone scan image depicting increased uptake in both PF and medial compartment of the right knee.
[21]. The deep, constraining trochlear groove of the Richards Mod I and II implants predisposed to subtle maltracking and catching of the implant on the trochlear edges. The Lubinus patellofemoral implant has been reported to have a high rate of reoperation for patellofemoral dysfunction [17]. In 2001, Tauro et al [17] reported the need for revision surgery in 28% of knees with the Lubinus prosthesis, primarily for patellar maltracking, with 32% of cases in the series having trochlear malalignment or patellar maltracking. Lonner et al [21] reported the incidence of patellofemoral dysfunction, subluxation, catching, and substantial pain to be 17% with the Lubinus prosthesis. Second-generation implants, such as the LCS mobile bearing (DePuy, Warsaw, IN), Autocentric (DePuy), and Avon (Stryker, Mahwah, NJ) have had greater short and midterm success. Reported success rates have ranged from 80% to 94% [22]. These next-generation PF implants have had higher success rates secondary to an improved trochlear design that reduced the incidence of patella maltracking. The Zimmer Gender Solutions PFJ system used in this study is an asymmetric design that takes into consideration that the vast majority of PFA recipients are women. It has done this by increasing its trochlear groove angle to accommodate the higher Q angle typical of female patients in all except its largest size. This design feature enhanced patellar femoral tracking and minimized the need for lateral release during the procedure [23]. The amount of surface contact between the patellar component and native cartilage has been reduced by extending the proximal extent of the trochlear component and refining the transitional point between the anterior trochlear flange and the intercondylar portion. Additionally, shorting the intercondylar tail has reduced impingement on the
proximal pole of the patellar component. The patellar component is a typical all-polyethylene modified dome that can be retained if a revision to a TKA is required for disease progression. The instruments were also designed for simplicity and accuracy [23]. A recent meta-analysis demonstrated there is no statistically significant difference between second-generation PFA and TKA in the development of mechanical complications, persistent pain after surgery, reoperation rate, or revision arthroplasty [24]. PFA is a viable treatment option for patients with isolated PF arthritis. These results are in accordance with our study findings of no mechanically related failures necessitating revision surgery. A 2012 meta-analysis by Dy et al [24] showed that about 30% of PFA revisions are due to the progression of OA. Leadbetter et al [25] also showed a similar rate of revision due to progression of OA. A study by Nicol et al [26] showed that when using a secondgeneration PFA system, progression of tibia-femoral arthritis was the etiology leading to revision in 86% of patients. Our data along with that of prior meta-analysis studies underscore the need to develop strict patient selection criteria to further improve survivorship in patients undergoing isolated PFA. Progression of underlying arthritis is the main etiology leading to failure of PFA with subsequent revision to TKA. Dieppe et al [9] demonstrated that bone scan was able to predict the progression of OA in the knee. In their study of 94 patients, none of the 55 patients without abnormalities on entry examinations had evidence of progression of OA, resulting in a negative predictive value of 100% and a negative likelihood ratio (LR) of 0% [9]. In comparison,
Patellofemoral Joint Arthroplasty Survivorship with MRI preoperavely
Table 1 Patient Demographics.
Total number of cases Number of males Number of females Mean age at surgery Mean BMI Mean follow-up
Bone Scan Cohort
1
MRI Cohort
16
16
3
3
13
13
48.44, SD ¼ 7.2 (range 33-60) 33.80, SD ¼ 8.64 (range 21.9-49.02) 52.37 mo, SD ¼ 21.14 (range 29.9-104.5)
47.75, SD ¼ 6.77 (range 37-61) 29.33, SD ¼ 5.02 (range 21.6-38.4) 63.11 mo, SD ¼ 26.26 (range 38.0-115.4)
t-Test (P Value)
.7829 .0836 .2125
MRI, magnetic resonance imaging; BMI, body mass index; SD, standard deviation.
Survivorship Probability%
Demographics
0.8 0.6 0.4 0.2 0
0
1
2
3
4
5
6
7
8
9
Time in Years
Fig. 3. Patellofemoral joint arthroplasty survivorship with MRI preoperatively.
4
J.F. Baker et al. / The Journal of Arthroplasty xxx (2019) 1e4
a meta-analysis by Menashe et al [27] examining MRI prediction of OA progression reported a negative predictive value of 57% and a LR of 0.48. LRs below 0.1 provide strong evidence to rule out a diagnosis [28]. The above studies indicate that a negative bone scan can more reliably rule out the presence of OA than a negative MRI. Early stages of OA have been associated with increased subchondral bone turnover and therapies to decrease subchondral activity have been hypothesized to slow the progression of OA [29,30]. Bone scans detect this increased activity of the subchondral bone and thus increased periarticular activity on bone scan may suggest a more rapid progression of OA [9,29,30]. Our study also supports the ability of bone scans to predict OA progression, as no patient who had a negative bone scan and received a PFA required a revision due to progression of the disease. In our study, PFA using a modern implant design coupled with preoperative bone scan in patient selection demonstrated 100% survivorship. In those undergoing only preoperative MRI there was a 31% failure due to progression of OA. If the advantages of PFA can be paired with the durability of a TKA by coupling modern design and surgical methods with a reliable predictor for progression of OA, PFA may become the treatment of choice for isolated PFJ OA. Based on this study and the available literature, we would recommend the use of a preoperative bone scan as a helpful tool in the selection process for patients considering isolated PFA. References [1] Stefanik JJ, Niu J, Gross KD, Roemer FW, Guermazi A, Felson DT. Using magnetic resonance imaging to determine the compartmental prevalence of knee joint structural damage. Osteoarthr Cartil 2013;21:695e9. [2] Hunter DJ, March L, Sambrook PN. The association of cartilage volume with knee pain. Osteoarthr Cartil 2003;11:725e9. [3] Insall J, Tria AJ, Aglietti P. Resurfacing of the patella. J Bone Joint Surg Am 1980;62:933e6. [4] Mont MA, Haas S, Mullick T, Hungerford DS. Total knee arthroplasty for patellofemoral arthritis. J Bone Joint Surg Am 2002;84-a:1977e81. [5] Hoogervorst P, de Jong RJ, Hannink G, van Kampen A. A 21% conversion rate to total knee arthroplasty of a first-generation patellofemoral prosthesis at a mean follow-up of 9.7 years. Int Orthop 2015;39:1857e64. [6] van der List JP, Chawla H, Villa JC, Pearle AD. Why do patellofemoral arthroplasties fail today? A systematic review. Knee 2017;24:2e8. [7] Williams DP, Pandit HG, Athanasou NA, Murray DW, Gibbons CL. Early revisions of the Femoro-Patella Vialla joint replacement. Bone Joint J 2013;95-b:793e7. [8] Barr AJ, Campbell TM, Hopkinson D, Kingsbury SR, Bowes MA, Conaghan PG. A systematic review of the relationship between subchondral bone features, pain and structural pathology in peripheral joint osteoarthritis. Arthritis Res Ther 2015;17:228.
[9] Dieppe P, Cushnaghan J, Young P, Kirwan J. Prediction of the progression of joint space narrowing in osteoarthritis of the knee by bone scintigraphy. Ann Rheum Dis 1993;52:557e63. [10] Ackroyd CE, Chir B. Development and early results of a new patellofemoral arthroplasty. Clin Orthop Relat Res 2005:7e13. [11] Odumenya M, McGuinness K, Achten J, Parsons N, Spalding T, Costa M. The Warwick patellofemoral arthroplasty trial: a randomised clinical trial of total knee arthroplasty versus patellofemoral arthroplasty in patients with severe arthritis of the patellofemoral joint. BMC Musculoskelet Disord 2011;12:265. [12] Dahm DL, Al-Rayashi W, Dajani K, Shah JP, Levy BA, Stuart MJ. Patellofemoral arthroplasty versus total knee arthroplasty in patients with isolated patellofemoral osteoarthritis. Am J Orthop (Belle Mead NJ) 2010;39:487e91. [13] Tarassoli P, Punwar S, Khan W, Johnstone D. Patellofemoral arthroplasty: a systematic review of the literature. Open Orthop J 2012;6:340e7. [14] Arciero RA, Toomey HE. Patellofemoral arthroplasty. A three- to nine-year follow-up study. Clin Orthop Relat Res 1988:60e71. [15] Board TN, Mahmood A, Ryan WG, Banks AJ. The Lubinus patellofemoral arthroplasty: a series of 17 cases. Arch Orthop Trauma Surg 2004;124:285e7. [16] Krajca-Radcliffe JB, Coker TP. Patellofemoral arthroplasty. A 2- to 18-year followup study. Clin Orthop Relat Res 1996:143e51. [17] Tauro B, Ackroyd CE, Newman JH, Shah NA. The Lubinus patellofemoral arthroplasty. A five- to ten-year prospective study. J Bone Joint Surg Br 2001;83:696e701. [18] McKeever DC. Patellar prosthesis. J Bone Joint Surg Am 1955;37-a:1074e84. [19] Blazina ME, Fox JM, Del Pizzo W, Broukhim B, Ivey FM. Patellofemoral replacement. Clin Orthop Relat Res 1979:98e102. [20] Lubinus HH. Patella glide bearing total replacement. Orthopedics 1979;2: 119e27. [21] Lonner JH. Patellofemoral arthroplasty: pros, cons, and design considerations. Clin Orthop Relat Res 2004:158e65. [22] Ackroyd CE, Newman JH, Evans R, Eldridge JD, Joslin CC. The Avon patellofemoral arthroplasty: five-year survivorship and functional results. J Bone Joint Surg Br 2007;89:310e5. [23] Lonner JH. Patellofemoral arthroplasty: the impact of design on outcomes. Orthop Clin North Am 2008;39:347e54. vi. [24] Dy CJ, Franco N, Ma Y, Mazumdar M, McCarthy MM, Gonzalez Della Valle A. Complications after patello-femoral versus total knee replacement in the treatment of isolated patello-femoral osteoarthritis. A meta-analysis. Knee Surg Sports Traumatol Arthrosc 2012;20:2174e90. [25] Leadbetter WB, Ragland PS, Mont MA. The appropriate use of patellofemoral arthroplasty: an analysis of reported indications, contraindications, and failures. Clin Orthop Relat Res 2005:91e9. [26] Nicol SG, Loveridge JM, Weale AE, Ackroyd CE, Newman JH. Arthritis progression after patellofemoral joint replacement. Knee 2006;13:290e5. [27] Menashe L, Hirko K, Losina E, Kloppenburg M, Zhang W, Li L, Hunter DJ. The diagnostic performance of MRI in osteoarthritis: a systematic review and meta-analysis. Osteoarthr Cartil 2012;20:13e21. [28] Deeks JJ, Altman DG. Diagnostic tests 4: likelihood ratios. BMJ 2004;329: 168e9. [29] Radin EL, Rose RM. Role of subchondral bone in the initiation and progression of cartilage damage. Clin Orthop Relat Res 1986:34e40. [30] Castaneda S, Roman-Blas JA, Largo R, Herrero-Beaumont G. Subchondral bone as a key target for osteoarthritis treatment. Biochem Pharmacol 2012;83: 315e23.