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ISSN: 2161-0533

Orthopedic & Muscular System:
Current Research

Kurose et al., Orthopedic Muscul Syst 2014, 3:3
DOI: 10.4172/2161-0533.1000166

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Research Article

Open Access

Clinical Results of Posterior Cruciate Ligament–Retaining Total Knee
Arthroplasty in Patients with Rheumatoid Arthritis: A 5- to 13-Year Follow-up
Study
Rie Kurose, Hiroshi Kakizaki and Hiroyuki Akimoto
Department of Orthopedic Surgery, Hirosaki National Hospital, Hirosaki, Japan*Corresponding author: Rie Kurose, Department of Orthopedic Surgery, Hirosaki National Hospital, 1 Tomino-cho, Hirosaki City, Aomori 036-8545, Japan., Tel:

81-172-39-5083; Fax: 81-172-36-3826; E-mail: riekuro@aol.com
Received date: July 28, 2014, Accepted date: Aug 30, 2014, Published date: Sep 9, 2014
Copyright: © 2014, Kurose R, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted
use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract
Aim: Total knee arthroplasty (TKA) is commonly performed to relieve pain and improve function in patients withrheumatoid arthritis (RA). However, treatment with posterior cruciate ligament–retaining (CR-type) TKA is thought tobe controversial, particularly in patients with RA. In the present study, we aimed to investigate the clinical results ofCR-type TKA and evaluate the efficacy of this type of prosthesis in patients with RA.
Methods: In our hospital, 77 CR-type TKA procedures were performed in 59 patients with RA between January
2001 and 2008. In total, we assessed 45 CR-type TKA procedures in 30 patients with RA who underwent follow-up
for at least 5 years. The assessment was based on the Knee Society clinical score (KSS) and an independentradiographic analysis.
Results: During a mean follow-up period of 8 years, 2 patients developed late infection and 2 other patients
experienced supracondylar fracture after each TKA procedure. After surgery, the KSS improved significantly among
the patients and 87% of the patients did not experience any pain. Moreover, the mean postoperative maximum
flexion angle was 114.8°, whereas the maximum extension angle was -4.2°.
Conclusion: Although additional long-term follow-up studies are required, the results of our medium-term followup study indicate that CR-type TKA was not problematic, even in patients with RA.

Keywords: Clinical results; Posterior cruciate ligament–retaining
type; Rheumatoid arthritis; Total knee arthroplasty

Introduction
The affected joints in patients with rheumatoid arthritis (RA) are
known to exhibit chronic proliferative synovitis, which is implicated in
the destruction of articular cartilage and bone, resulting in joint
disability. Good clinical results of total knee arthroplasty (TKA)
involving the use of several types of prosthesis have been reported inpatients with RA. However, no consensus has been established onwhether the posterior cruciate ligament (PCL) should be replaced orretained, since Laskin and O’Flynn reported that posterior cruciate
ligament–retaining (CR-type) TKA might result in postoperative
posterior instability of >10 mm [1].
In the present study, we clinically evaluated a consecutive series ofpatients with RA who underwent CR-type TKA by a single surgeon
between January 2001 and 2008. Thus, we aimed to investigate theclinical results of CR-type TKA and evaluate the efficacy of this type of
prosthesis in patients with RA.

Methods
Patients: A total of 77 primary CR-type TKAs were performed in 59
patients with RA by a single surgeon in our hospital between January
2001 and 2008. In the present study, we assessed 45 TKAs that were

Orthopedic Muscul Syst
ISSN:2161-0533 OMCR, an open access journal

performed in 30 patients with RA who underwent follow-up clinicalevaluations for >5 years (Table 1). The mean follow-up period was 8
years (range, 5–13 years). The study population comprised 25 womenand 5 men with a mean age of 66.1 years (range, 47–79 years) at thetime of surgery. All patients fulfilled the 1987 diagnostic criteria of theAmerican College of Rheumatology [2]. Moreover, all patients werereceiving oral therapy for RA at the time of surgery and none hadreceived biologic therapy prior to surgery.
Operative procedure: All operative procedures involved the use of atourniquet. An anterior midline or lateral parapatellar skin incision
was made, and the knee joint was opened through a midvastus ormedial parapatellar approach. The PCL was preserved in all cases.
The synovium attached to the suprapatellar pouch, bilateral gutters,
and posterior capsule as well as that surrounding the cruciate
ligaments was resected as much as possible. The femur and tibia were
cut using an intramedullary rod and extramedullary rod, respectively.
Two types of prosthesis—the Foundation Total Knee System (Encore,
CA, USA) and the Flexible Nichidai Knee (FNK; Nakashima Medical,
Okayama, Japan)—were used randomly (Figure 1). The tibial stem of
the former has a wing-keel design, whereas that of the latter has across-shaped design. Cancellous bone chips were used to fill bony
defects. The patellae were fixed with all-polyethylene components andcement. Tibial and femoral components were fixed with cement only
in cases of severe osteoporosis. Postoperative antibiotic therapy(cefmetazole sodium, 1 g) was administered twice daily for 3 days. All

Volume 3 • Issue 3 • 1000166

Citation:

Kurose R, Kakizaki H, Akimoto H (2014) Clinical Results of Posterior Cruciate Ligament–Retaining Total Knee Arthroplasty in Patientswith Rheumatoid Arthritis: A 5- to 13-Year Follow-up Study. Orthopedic Muscul Syst 3: 166. doi:10.4172/2161-0533.1000166

Page 2 of 4
patients were managed with a foot pump rather than by chemical
thromboprophylaxis. Range of motion exercise and full weightbearing transfer to a wheelchair were initiated on the second
postoperative day, and patients gradually initiated routine
physiotherapy with weight bearing, as tolerated. Patients weredischarged when they could walk with a T-cane and tolerate stair
climbing or were transferred to another hospital for rehabilitation.
Knees (Patients)

45 knees (30 patients)

Mean age (years)

66.1 (47 to 79)

Male/female (%)

16.7 / 83.3

Duration of follow-up (years)

8.2 (5 to 13)

Cement/cementless (knees)

39 / 6

FNK/ The Foundation Total Knee System (knees)

17 /28

Table 1: Clinical data of 30 patients with RA.

according to the Knee Society TKA roentgenographic evaluation andscoring system [4]. The occurrence of complications, including
infection and fracture, were also assessed.

Figure 2: The Knee Society roentgenographic evaluation andscoring system [4]; (a) Lateral view of a femoral component, (b)Anteroposterior view of a tibial component, (c) Lateral view of atibial component, (d) Lateral view of a patellar component.
Statistical analysis: Statistical analysis was performed using theStudent’s t test for the comparison of preoperative and postoperative
clinical scores. A p-value of <0.05 was considered statisticallysignificant.

Results
Clinical results

Figure 1: Two types of prosthesis used for posterior cruciate
ligament–retaining (CR-type) TKA in this study; (a) Anterior viewof the Flexible Nichidai Knee (FNK) CR-type component, (b)Anteroposterior (AP) and lateral radiographs of the FNK CR-type
component, (c) Anterior view of the Foundation Total Knee System
CR-type component, (d) AP and lateral radiographs of theFoundation Total Knee System CR-type component.
Evaluation: Clinical evaluations were performed using the Knee
Society clinical score (KSS) [3], which separately assesses themechanical and functional aspects of the knee joint. All patients were
evaluated preoperatively and postoperatively by an orthopedic surgeon—other than the surgeon who performed the operation-at 1, 3, and 6
months, and then at yearly intervals. Weight-bearing anteroposterior(AP), lateral, and skyline radiographs were obtained at each follow-up
visit according to standard protocol described previously [4]. The
postoperative femorotibial angle (FTA) of the knee joint was measured
on weight-bearing AP radiographs. Radiolucencies were evaluatedaccording to the zone described by the Knee Society (Figure 2) [4]. AP
and mediolateral instability were also evaluated at each visit. Standard
AP and lateral radiographs at the final follow-up visit were evaluatedfor the presence of loosening, a radiolucent line, and subsidence

Orthopedic Muscul Syst
ISSN:2161-0533 OMCR, an open access journal

Figure 3: Mechanical score (a) and functional score (b) of the Knee
Society clinical score (KSS). In both scores, the scores at the time of
final visit were significantly higher than that at the time ofpreoperatively. * means p <0.01.
The average Knee Society knee rating score improved from 41.9
(range, 12–69) preoperatively to 91.3 (range, 73–100) at the final
follow-up evaluation (p < 0.01). The average Knee Society function
score also improved from 14.4 (range, 0–40) preoperatively to 83.1
(range, 60–100) at the final follow-up evaluation (p < 0.01) (Figure 3).
During the postoperative period, 39 knees (87%) were pain free,whereas 6 knees (13%) had mild or occasional pain. The mean
preoperative maximum flexion angle was 110.3° (range, 70°–150°),
whereas that at the final follow-up was 114.8° (range, 80°–125°). The

Volume 3 • Issue 3 • 1000166

Citation:

Kurose R, Kakizaki H, Akimoto H (2014) Clinical Results of Posterior Cruciate Ligament–Retaining Total Knee Arthroplasty in Patientswith Rheumatoid Arthritis: A 5- to 13-Year Follow-up Study. Orthopedic Muscul Syst 3: 166. doi:10.4172/2161-0533.1000166

Page 3 of 4
mean preoperative and final follow-up maximum extension angles
were -13.4° (range, -40° to 0°) and -4.2° (range, -60° to 0°), respectively(p < 0.01) (Figure 4). We noted that good valgus–varus stability wasmaintained manually throughout the follow-up period in all thepatients.

Laboratory data
The serum levels of C-reactive protein (CRP), rheumatoid factor(RF) and matrix metalloproteinase-3 (MMP-3) improved from 3.71
mg/dl, 175.60 mg/dl and 616.00 ng/ml preoperatively to 2.15, 106.40
and 293.97 at 1 year after surgery and to 1.18 (p < 0.05), 70.56 and157.17 at the final follow-up, respectively.

Complications
Among the knees examined, complications occurred in 4 knees(8.9%), including late deep infection in 2 knees and supracondylar
fracture above the TKA in 2 knees. The 2 cases of infection required
irrigation surgery, but none of the case required revision surgery. In
addition, no cases of nerve palsy, pulmonary embolism, deep veinthrombosis, or patellar fracture were observed.

Discussion
Figure 4: Range of motion after posterior cruciate ligament–
retaining (CR-type) TKA. Upper (triangle mark) and lower(diamond mark) lines indicate maximum flexion and maximum
extension angles of the knee at the time of preoperatively (Preope.),one month (1M), one year (1Y), five year (5M), and final visit,
respectively. * means p <0.01.

Radiographic results
The mean preoperative FTA was 177.5° (range, 168°–193°), whereasthat at the final follow-up was 171.8° (range, 166°–180°) (Figure 5). All
the patients in the study were assessed for radiolucency at the bone–
implant interface. Radiolucencies were identified in 18 knees (15patients); 18 lesions were observed at the femoral component (zone 1,
9 knees; zone 2, 2 knees; and zone 4, 7 knees) and 25 lesions wereobserved at the tibial component (AP view: zone 1, 11 knees; zone 2, 6
knees; zone 3, 4 knees; and zone 4, 4 knees; lateral view: zone 1, 3
knees). All lesions were less than 1 mm in length and were
nonprogressive. No radiolucent line was noted in the patellar
component, and no evidence of radiographic loosening was observedat any follow-up visit. Moreover, no failures as a result of subsidence,
tibial component loosening, or polyethylene wear were noted.

Figure 5: The femorotibial angle (FTA) after posterior cruciate
ligament–retaining (CR-type) TKA. The points of left mean FTA at
the time of preoperatively and those of right mean FTA at the timeof final visit.

Orthopedic Muscul Syst
ISSN:2161-0533 OMCR, an open access journal

TKA is a reliable form of treatment to relieve pain and improvefunction in patients with RA. However, it remains unclear whether it isbest to retain or excise the PCL because the choice of the method
employed—CR-type or posterior-stabilized (PS-type)—is based onlimited data. Since Laskin and O’Flynn [1] described a series of 98
knees in patients with RA who were managed with CR-type TKA, thistype of TKA has been believed to be a relative contraindication incases of RA. In their paper, it was reported that 50% of knees
developed postoperative posterior instability of >10 mm. Based on
those results, many surgeons presently prefer treatment with PS-type
TKA for patients with RA. Also, PS-type TKA involves an easier
operative technique and results in better range of motion as compared
to CR-type TKA for patients with RA. In addition, in their study of PStype TKA, Shai et al. [5] reported a prosthesis survival rate of 97% at
13 years, and Rodriguez et al. [6] also reported a good survival rate of
91% at 15 years.
However, several modern studies comparing cruciate–retaining
with cruciate-substituting designs have demonstrated similar resultswith regard to range of motion, aseptic loosening, proprioception, gait
patterns, polyethylene wear, and stability [7,8]. Furthermore, anumber of recent studies have demonstrated good medium-term
results following CR-type TKA in patients with RA [9-11].
Additionally, Conditt et al. [12] reported that the substitution of the
PCL using a spine and cam mechanism might not completely restore
the functional capacity of the PCL, particularly in high-demand
activities that may involve deep flexion, squatting, and kneeling, suchas gardening. In the present study on CR-type TKA, both themechanical and functional KSS scores were found to improvesignificantly after the procedure (Figure 3). Although complications
developed in 10% of knees, none of the cases required revision surgery.
At least in this follow-up period, it was no problem after the operation.
Based on our results, we believe that CR-type TKA could be the first
method of choice for patients with RA, with certain exceptions.
However, we believe that PS-type TKA should be selected in cases
where the PCL is not robust and mutilating-type RA, severe deformity,
severe knee stiffness, or severe knee instability is noted.
However, the disease state of RA at the time of TKA might
determine whether the PCL should be retained or sacrificed. Posterior
instability generally develops in advanced rheumatoid disease;
however, recently, combination therapy with disease-modifying
antirheumatic drugs and/or biologic agents has substantially improved
the control of RA. Furthermore, there have been reports from Western

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Citation:

Kurose R, Kakizaki H, Akimoto H (2014) Clinical Results of Posterior Cruciate Ligament–Retaining Total Knee Arthroplasty in Patientswith Rheumatoid Arthritis: A 5- to 13-Year Follow-up Study. Orthopedic Muscul Syst 3: 166. doi:10.4172/2161-0533.1000166

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countries and Japan that the rates of total joint replacement, includingthat of the hip and knee, and other RA-related surgeries have been
constant or decreased in patients with RA due to the availability of
new medications, including biologic agents [13]. In the present study,
none had received biologic agents for RA control at the time of TKA
although 9 patients (20%) used them at the final follow-up visit. Then,both the clinical score—including an evaluation of posterior instability—and laboratory data were unchanged or had improved. These
indicate that advancements in systemic disease control could effect on
postoperative results.
In the present study, there were no problems associated with theretention of the PCL. However, surgeons should carefully consider the
potential development of such complications in future cases. Thus, theappropriate selection of patients based on the RA status, prosthesis
type, and operative technique may lead to good clinical results, evenwhen using CR-type TKA.

Conclusion
In conclusion, although our study did not evaluate whether CRtype TKA is superior to PS-type TKA, our results indicate that CRtype TKA did not result in any problems in patients with RA during
the follow-up period. However, additional long-term follow-up studies
are required.

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