Skip to main content
NCBI home page
Journal of Orthopaedics logoLink to Journal of Orthopaedics
. 2019 Dec 10;20:6–11. doi: 10.1016/j.jor.2019.12.001

Clinical outcome, functional outcome and patient satisfaction after cruciate retaining total knee arthroplasty for stiff arthritic knee - A short term outcome study

Prabhudev Prasad Purudappa a,∗, Om Prakash Sharma b, Jayadev Chandrasekharan c, Prasanth Jayakumari Sudevan c, Varatharaj Mounasamy d, Senthil Nathan Sambandam a
PMCID: PMC6995260  PMID: 32021048

Abstract

Background

Various authors have shown that Cruciate Retaining (CR) Total Knee Arthroplasty (TKA) has better long-term survivorship compared to Posterior Stabilized (PS), however most arthroplasty surgeons tend to use PS knees in patients with severe deformity and stiffness. There is limited data correlating stiffness and CR versus PS design. The aim of our study was to assess the outcome of CR TKA for patients with stiff arthritic knee.

Materials & methods

We evaluated the results of 30 knees with osteoarthritis and inflammatory arthritis and preoperative stiffness (ROM 15-90°), who had been treated with CR TKA with a mean follow up of 2 years. The primary outcome variable measures were improvement in the flexion, flexion deformity (FFD) and overall improvement in the arc of motion. Patients were also evaluated by Knee Society Score (KSS), WOMAC score and 5-point Likert scale for patient satisfaction.

Result

At the time of final follow-up, the mean arc of motion improved from 75° preoperatively to 108° postoperatively and it was statistically significant (p < 0.001). Similar improvement was noted for FFD (15.43° to 0.83° (p < 0.001)), maximum flexion from 90.9° to 109.1° (p < 0.001), KSS clinical from 37.67 to 87.47 (p < 0.001), KSS functional from 58.5 to 93.83 (p < 0.001), WOMAC from 76.73 to 7.63 (p < 0.001). Further, the Likert Scale for patient satisfaction was excellent for 90% of the patients.

Conclusion

This study clearly shows that the routine use of PS design for complex stiff knees has questionable scientific intent and standard CR TKA design in stiff knees can produce excellent outcome. Since there is slight preponderance of data pointing towards improved longevity with CR design, it would be a better option for the patients with longer life expectancy.

Keywords: Stiff knee, Cruciate retaining, Posterior stabilized

1. Introduction

Osteoarthritis (OA) is the fourth leading cause of ‘years lived with disability’ (YLDs), accounting for 3.0% of total global YLDs. By 2030, in United States the demand for primary total knee arthroplasty (TKA) is predicted to widen its margin by 673% and reach to 3.48 million procedures.1 With a view to improve the quality of life by the reduction of pain, restoration of the function and improvement of stability, patients with severe osteoarthritis of knee joint often require total knee arthroplasty.2 It has been shown that a minimum of 67° of knee flexion is required for the swing phase of the gait cycle, 83° needed to climb the stairs, 90° to descend stairs and at least 93° to getting up from a chair.3 The minimum knee flexion required for usual daily activity is generally considered as 90°.4 Stiff osteoarthritic knee causes significant activity limitation, increases the energy expenditure during locomotion, and decreases the gait velocity and step length and in short affects the quality of life of an individual. Patient with a decreased preoperative range of movement is a challenge for surgeons because of increased complications and revision rate.5 There is an element of disagreement existing among arthroplasty surgeons when defining stiff knee. In general, knees with a Fixed Flexion Deformity (FFD) more than or equal to 15° and/or flexion less than or equal to 90° are considered as stiff knee. The aim of TKA is to give good pain relief, improve ambulation and provide good range of movements. Range of movement is an important component of routine Total knee arthroplasty. The post operative ROM is mainly determined by preoperative range of movements.6, 7, 8 Various types of designs are now available with specific features regarding the geometry of the components, the degree of conformity of the articulating surface and the anchoring technique. Among these, Cruciate retaining (CR) and Posterior stabilized (PS) prosthesis are the commonly used prosthesis with good clinical, functional out come and reasonable long-term survivorship. Various authors have reported that PS knee has a slightly better flexion compared to CR knees.9,10 However, there is preponderance of data including the Mayo data, studies from high volume centers all over the world11,12 and the most recent annual reports of the available Joint registry data13, 14, 15, 16, 17, 18 pointing towards increased long-term survival with CR knees. Further, the increase in the ROM noted with PS design has not shown to significantly affect the final overall outcome of patient with or without stiffness.19,20 Despite the comparable clinical outcome and better longevity of CR TKA, most arthroplasty surgeons around the world tend to use PS knees in patients with severe deformity, stiffness and other complex situations.21 This is often due to the perception of increased postoperative flexion achieved with PS implants. In this study we hypothesized that, CR design can provide significant improvement in movement, good clinical and functional outcomes even in patients with pre-operative stiffness and routine use of PS design is questionable. In this study we evaluated the short term clinical and functional outcomes after cruciate retaining TKA for stiff knee. We included knees with a minimum of 2 year follow up, because the range of motion remains stable after that.22,23

2. Materials and method

This is a hospital based longitudinal study in which the data was collected prospectively. The study was conducted at a tertiary teaching facility. All patients who underwent Primary Cruciate Retaining TKA during March 2014–June 2015 were screened for inclusion criteria. All cases were operated by one Orthopaedic surgeon (SNS) and standard preoperative, intraoperative and postoperative protocol were used in all patients. Patients with primary or secondary osteoarthritis and inflammatory arthritis with fixed flexion deformity (FFD) more than or equal to 15°, flexion less than or equal to 90° and patients available for at least one year follow up were included. Patients with sepsis of the knee joint, patients who are non-compliant with institutional physical therapy protocol, Charcot's joint, neuromuscular disorders and patient who lost follow up were excluded from this study. A total of 28 patients (30 knees) were included in this study. All cases were reviewed, and data was recorded by an orthopedic surgeon not included in the surgical team. The study included eight males (27%) and twenty females (22 knees, 73%, two female patients had bilateral TKA). The mean age was 61 (range-50 to 80, SD±7.4). Twenty-six patients (87%) were diagnosed with primary osteoarthritis and four patients (13%) were diagnosed as inflammatory arthritis. The mean follow-up was 2 years.

Preoperatively, detailed history, clinical, radiological (Fig. 1, Fig. 5) and laboratory evaluation were recorded, knee FFD and total flexion were assessed preoperatively. The patients were admitted after thorough pre surgical work up and infective foci was ruled out or treated. Procedures were performed under combined spinal and epidural anesthesia. We used the anterior midline incision for skin and a medial parapatellar retinacular approach for the retinaculum. The medial side of the knee was exposed by subperiosteally stripping the antero-medial capsule and deep medial collateral ligament off the tibia to the posteromedial corner of the knee. An intramedullary jig was used for resection of the distal femur and extramedullary jig for tibial cuts. A bone block was kept on the tibial surface to secure the PCL attachment. Preliminary (and often final) ligament balancing was accomplished during initial exposure prior to final preparation of the femur and tibia. Extensive posterior capsular release was performed in all patients with preoperative FFD. Varus/valgus stability in flexion was achieved via femoral component rotation. Fine-tuning of all aspects of ligament balancing was done after placement of the trial components. Patella was resurfaced in all cases. The final components were implanted after through preparation of the bone surfaces with pulsed lavage. The tibial tray was implanted first followed by the femoral component, appropriate insert was placed in position and knee was reduced. A three peg all poly oval domed patellar component was then cemented and compressed with the clamp. All components were cemented simultaneously with one batch (40 g) of cement. Twenty-one (70%) knees implanted with Depuy PFC Sigma CR knee and nine (30%) with Smith and Nephew Genesis II CR knee. The total flexion and extension were assessed after releasing the tourniquet. The knee joint was closed in a standard fashion over a drain.

Fig. 1.

Fig. 1

Open in a new tab

Pre operative x-rays.

Fig. 5.

Fig. 5

Open in a new tab

Pre-operative x-ray.

All patients received DVT prophylaxis for 2 weeks with low molecular weight heparin and a standard multimodal pain management was done postoperatively. Drain removal was done with in 48 h for all cases. Standard prophylactic antibiotic prophylaxis was done with first generation cephalosporins for 24 h. Patient was started with standard physical therapy protocol from first post-operative day. Patients underwent supervised physical therapy twice a week for 4–6 weeks. Post operatively all the patients were followed up at 2 weeks, 6 weeks, 3 months, 6 months, 1 year and 2 years, post op X-rays were done at 6 weeks follow up (Fig. 2, Fig. 6). At each follow up the patients were made to undergo a series of testing at our physical therapy department (Fig. 3, Fig. 4, Fig. 7, Fig. 8). Patient's clinical and functional status was evaluated according to the variables scoring system. The WOMAC, Knee Society Score, 5-point Likert score for patient satisfaction were scored according to the post-operative status.

Fig. 2.

Fig. 2

Open in a new tab

Post operative x-rays.

Fig. 6.

Fig. 6

Open in a new tab

Post-operative x-ray.

Fig. 3.

Fig. 3

Open in a new tab

No FFD after TKA

Post-operative maximum flexion of 120°

Fig. 4.

Fig. 4

Open in a new tab

Alignment-supine and standing.

Fig. 7.

Fig. 7

Open in a new tab

No FFD after TKA

Post-op maximum flexion of 110°

Fig. 8.

Fig. 8

Open in a new tab

Stair ascendStair

descend.

3. Statistical analysis

The data were reported as the mean ± SD or the median, depending on their distribution. Frequencies are expressed in percentages. The differences in quantitative variables between groups were assessed by means of the Paired-t-test. Comparison between groups was made by the Non parametric Mann - Whitney test or unpaired t-test depending the distribution of the variable. Pearson coefficient of correlation was used to assess the relationship between the variables. The chi-square test was used assess differences in categorical variables between groups. A p value of <0.05 using a two-tailed test was taken as significance for all statistical tests. All data were analyzed with a statistical software package. (SPSS, version 16.0 for windows).

4. Results

The mean age was 61years (range- 50 to 80, SD±7.4) and average preoperative flexion was 90.9°. The mean preoperative FFD was 15.43 ± 9.9. Majority of the patients were females (73%). Most of the patients had one or two co-morbidities. Four out of thirty knees had secondary osteoarthritis due to rheumatoid arthritis. More than 90% of patients showed significant improvement in range of movements, walking distances and stair climbing capabilities from 6th month onwards. At the time of final follow-up, the arc of motion improved from 75° preoperative to 108° postoperative and it was statistically significant (p < 0.001). Similar statistically significant improvement was noted for fixed flexion deformity (15.43°–0.83° (p < 0.001), maximum flexion from 90.9° to 109.1 (p < 0.001), KSS clinical from 37.67 to 87.47 (p < 0.001), KSS functional from 58.5 to 93.83 (p < 0.001), WOMAC from 76.73 to 7.63 (p < 0.001). Further, the Likert-Scale for patient satisfaction was excellent for 90% of the patients. There were no major complications (Table 1).

Table 1.

Data summary of clinical variables and results.

Age 61 ± 7.4
Gender
Male/Female 27%/73%



Diagnosis
Osteoarthritis 87%
Rheumatoid arthritis 13%
Side
Right/Left 47%/53%
Comorbidities
Yes 83%
No 17%
Improvement in arc of Motion
Mean value 33.37 + 12.46
Range
20–39° 73%
40–59° 23%
>60° 3%
5- point Likert scale
Excellent 90%
Good 10%
Mean of Clinical variables Pre op Post op significant
FFD 15.43 ± 9.990 0.83 ± 1.960 <0.001
ROM 90.9 ± 14.300 109.1 ± 7.110 <0.001
Arc of motion 75.3 108 <0.001
KSS clinical 37.67 ± 9.93 87.47 ± 3.76 <0.001
KSS functional 58.5 ± 23.05 93.83 ± 7.84 <0.001
WOMAC Score 76.73 ± 5.06 7.63 ± 5.67 <0.001
Major Complications- Nil
Open in a new tab

None of the patients had post-operative manipulation for improving range of motion. There were no significant postoperative complications except one patient who had stitch abscess which was treated with suture removal and antibiotics. Post-operative radiography did not show any features of loosening or osteolysis at 2 years.

5. Discussion

It is a well-known fact that the improvement in ROM achieved after TKA is determined by the preoperative ROM.24,25Some authors have described inconsistent arc of movement and high risk of complications, high revision rates, with preoperative stiff knees.26,27 In contrast, others have reported same improvement in postoperative arc of motion in patients with stiff and ankylosed knees as that of patients with flexible knees with low complication rates.4,6 Almost all the studies used posterior stabilized design. There is no study in the literature which critically analyzed the outcome of stiff osteoarthritic knee using CR design (Table 2). Our study shows that CR knees can produce good to excellent results in stiff osteoarthritic knees.

Table 2.

literature review.

Authors Number of knees FFD
 Total flexion
 Arc of motion
 KSS
 WOMAC
 Patient satisfaction
Clinical
 Functional
Pre Post Pre Post Pre Post Pre Post Post Post Pre Post
Debette et al.30 304
Flexion contracture-(n1)65, flexion deficict-(n2)239.		 ≥20° NG 83° 115° n1-69°,
n2- 75°		 n1- 108°,
n2- 107°		 NG NG NG NG NG NG 94% very satisfied/satisfied.
Montgomery et al.40 82 22° 10° 58° 94° 36° 93° NG NG NG NG NG NG NG
Winemaker et al.38 134 NG NG 80° 110.8± 18.8° NG NG NG NG NG NG NG NG NG
Aglietti et al.34 26 28° 7° 60° 85° 32° 78° NG NG NG NG NG NG 81% good/excellent.
Spicer et al.39 28 NG NG NG NG 47.5° 93.5° 28.8 82.2 24.6 77 NG NG NG
Massin et al.32 128 20± 10° 7± 8° 76± 19° 99± 17° NG NG NG NG NG NG NG NG NG
Kim et al.29 86 NG NG NG NG 40° 102° HSS- 42,
KSS- 11		 HSS- 84
KSS- 90		 42 84 73 34 NG
Bhan et al.37 90 NG NG NG NG 35–69° 1–94° 34.6 89.5 NG NG NG NG NG
Natarajan et al.36 80 NG NG 85° 115° NG NG 32 83 26 86 NG NG NG
Shah et al.31 CR knee-40 NG NG 72° 108° NG NG NG NG NG NG NG NG NG
Open in a new tab

NG- Not Given.

Stiffness is a frustrating problem for surgeon and patient.7 However, none of the literature shows any consensus about the precise definition of functional ROM. Patients require a knee flexion of 65° to walk, 70° to lift an object from the floor, 85° for stair climbing, 95° for comfortable sitting and standing and 105° for tying shoelaces.17,28 Kim et al.29 defined stiffness as a flexion contracture >15 and/or a maximum flexion <75. Debette et al.30 evaluated the outcome of 304 TKA with preoperative stiffness. They included knees with preoperative fixed flexion deformity of ≥20° and/or ROM of ≤90 in their study. Shah et al.31 and Massin et al.32 retrospectively analyzed the outcome of knee with preoperative stiffness. They defined knee flexion ≤90° as stiff knee. In our study, Knee flexion ≤90° and/or FFD of ≥ 15° were chosen as inclusion criteria because a minimum of 90° of flexion is needed to perform various activities of daily living.

In the current study, the mean post-operative FFD improved from 15.43 to 0.83° (Range – 0 to 7, SD ±1.967°) postoperatively and the P value was highly significant (<0.001). There are only limited data available in the literature regarding patients who had undergone TKR for stiff knee with FFD and all these authors routinely used PS implants. Cheng et al.33 compared the results of seventy-seven patients with and without preoperative stiffness. They noted that postoperatively, there was a significant (16.9 ± 5.7 VS 4.1 ± 6.0, p < 0.001) improvement in FFD at one year follow up. Massin et al.32 retrospectively evaluated the result of 46 knees after primary TKR with mean pre-operative flexion contracture of 28±10°. They found that, post-operatively at one year follow up, the FFD was improved to 7 ± 8°. A study by Aglietti et al.34 also got similar type of result with 28 stiff knees with 4.5 years of follow up. Cloutier et al.35 pointed out that, by reducing fixed flexion contractures from an average of 25° to 3°, greatly alleviates stress across the knee and improves the function of the knee.

Among the 28 patients (30 knees), who underwent CR TKR with mean pre-operative flexion of 90.9°, the maximum flexion improved to 109.07° postoperatively (p < 0.001). Again, literature is sparse with regards to postoperative flexion in stiff knee and PS implant was used by most authors. Our results are comparable to the only available data reported by Shah et al. using CR implant. Shah et al.31 retrospectively evaluated the data of 40 CR knees with preoperative flexion of < 90°. The mean pre-operative flexion of 72° improved by mean 36° (p < 0.05) postoperatively at 2 year follow up. In all other studies30,32,36 authors used posterior stabilized design and reported that preoperative flexion improved by a range of 36–41°.

Our study shows a mean improvement in arc of motion of 33.37° (range-20 to 85, SD± 12.455). For the primary osteoarthritis it was 33.1 ± 13.2° and for the inflammatory osteoarthritis (Rheumatoid) it was 35.0 ± 7.1°. The minimum improvement in all groups was 20° and the maximum improvement was 85°. The P value was not significant (>0.05) when primary and secondary (Rheumatoid) OA were compared. Various studies29,30,33,37 showed improvement in arc of motion by 25–62°. One study38 retrospectively evaluated outcomes among patients with preoperative arc of motion of 80° or less with non-stiff preoperative knees with arc of motion 100° or greater. A total of 134 stiff knee cases were compared with a matched cohort of 134 non–stiff knee controls. Stiff knees experienced a significantly greater mean improvement in arc of motion from baseline to 1 year (30.8° ± 18.8°) as compared with non-stiff knees (1.1° ± 12.8°) (P < 0.0001). Spicer et al.39 in 2002, analyzed 28 stiff knees with the preoperative arc of motion of 60° or less. The outcome was reported at a mean follow-up of 52.9 months. Eighty-two percent of the cases were managed with posterior cruciate-retaining implants and 18% with a cruciate-substituting design. The mean postoperative arc of motion improved by 46°–93.5°. At the latest follow-up, 68.2% of knees achieved maximal flexion of 90° or more. These studies conclude that, a functionally useful range of motion is possible after total knee arthroplasty in majority of stiff osteoarthritic knees. However, majority of the studies available in the literature used constrained condylar, PS or posterior cruciate sacrificing design. Again, in our study we used CR design and it shows comparable results with studies which used Posterior stabilized/PCL sacrificing designs.

In our study, the mean preoperative Knee society clinical score was 37.67 and functional score was 58.5. At one-year follow-up, clinical score increased to 87.47 (P < 0.001) and the functional score increased to 93.83 (P < 0.001). Among the 30 patients assessed in this study, 29 patients (96.66%) had excellent, 1 patient (3.33%) had good results after the surgery for knee society clinical and functional score. Kim et al.29 analyzed the result of 86 stiff knees with a mean age of 56.8 years. They found that preoperative knee society clinical score of 11 improved to 90 and functional scores of 42 improved to 84 postoperatively. Debette et al.30 found that, in flexion deficit group (n-239), the knee score improved from 33 to 86 and in the flexion contracture group (N = 65), the knee score improved from 65 to 87 and this was significant (p < 0.05). Regarding functional scores, preoperative score of 48 and 51 improved to 72 and 77 respectively in each group and this was significant (p < 0.05). Bhan et al.37 Montgomery et al.40 also reported similar results regarding knee society clinical score. Considering knee functional score, Cheng et al.33 found that in 77 patients with preoperative stiffness, the knee score improved from 23.95 to 90.23 (p < 0.001). It is evident that the improvement observed in our series with CR knees is comparable to these large series in the literature. The highly significant improvement in Knee society clinical score and functional score may be because, our patients had severely degenerated knees.

With respect to WOMAC score, the mean pre-operative WOMAC score for pain, stiffness and physical function decreased from 76.73 (range- 68 to 85, SD-5.065) to 7.63 (range- 0 to 26, SD-5.67) postoperatively, at 1 year follow up. The P value was highly significant (<0.001) and it shows a negative correlation (r = −0.257). There is only one study available in the literature which analyzed the pre and post-operative WOMAC score of patients with knee stiffness. Kim et al.29 retrospectively reviewed 74 patients (86 knees) with stiff knees with a mean age of 56.8 years who underwent TKAs. In this study the preoperative WOMAC score of 73 decreased to 34 after TKA. Even though we used a CR design, our study showed similar results with above study in which they used either constrained condylar or PS design. In the present study the WOMAC score for pain, stiffness and function also improved substantially after TKA and majority of the patients in our group were home makers.

Patient satisfaction is an important measure of outcome and should be assessed in addition to the outcome scores. In our study, among the thirty patients with preoperative knee stiffness who underwent TKA, twenty-seven (90%) patients were extremely satisfied and three (10%) patients were satisfied after the surgery. Debette et al.30 observed that, 94% were satisfied or very satisfied with the results of their TKA and regarding activity levels, patients were significantly more active after surgery (p < 0.05). The present study shows that patient satisfaction is correlated with postoperative WOMAC score and knee society score. Majority of the patients in our study were extremely satisfied, it may be because all the patients who had undergone TKA had severe degenerative disease and they came for the surgery with severe symptoms.

We do understand that, the essential limitation of this study is lack of control group, so we compared our results with the published literature. The small number of patients included in this study is a major shortcoming, however considering the complexity and rarity of these significantly stiff knees encountered in routine arthroplasty practice we think thirty patients with stiff knee is clinically significant cohort. Also, short follow up of two years is another limitation but most studies fail to note any significant improvement in ROM after 1 year follow up.

6. Conclusion

This study clearly shows that the routine use of PS design for complex stiff knees has questionable scientific intent and standard Cruciate retaining TKA design in stiff knees can lead to significant improvement in postoperative mobility, clinical outcome and patient satisfaction. Since there is slight preponderance of data pointing towards improved longevity with CR design, it would be a better option for the patients with longer life expectancy. However strict adherence to post operative rehabilitation protocol is necessary.

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Declaration of competing interest

All the authors disclose that there are no conflicts of personal or financial interests with other people or organizations which might inappropriately influence this work.

Acknowledgements

None.

References

  • 1.Kurtz S., Ong K., Lau E. Projections of primary and revision hip and knee arthroplasty in the United States from 2005 to 2030. J Bone Joint Surg Am. 2007;89(4):780–785. doi: 10.2106/JBJS.F.00222. [published Online First: 2007/04/04] [DOI] [PubMed] [Google Scholar]
  • 2.Surgery of the Knee. second ed. Churchill Livingstone; New York: 1993. pp. 719–738. [Google Scholar]
  • 3.Ritter M.A., Harty L.D., Davis K.E. Predicting range of motion after total knee arthroplasty. Clustering, log-linear regression, and regression tree analysis. J Bone Joint Surg Am. 2003;85(7):1278–1285. doi: 10.2106/00004623-200307000-00014. [published Online First: 2003/07/10] [DOI] [PubMed] [Google Scholar]
  • 4.Gatha N.M., Clarke H.D., Fuchs R. Factors affecting postoperative range of motion after total knee arthroplasty. J Knee Surg. 2004;17(4):196–202. doi: 10.1055/s-0030-1248221. [published Online First: 2004/11/24] [DOI] [PubMed] [Google Scholar]
  • 5.Shi M.G., Lu H.S., Guan Z.P. Influence of preoperative range of motion on the early clinical outcome of total knee arthroplasty. Zhonghua Wai Ke Za Zhi. 2006;44(16):1101–1105. [published Online First: 2006/11/04] [PubMed] [Google Scholar]
  • 6.Harvey I.A., Barry K., Kirby S.P. Factors affecting the range of movement of total knee arthroplasty. J Bone Joint Surg Br. 1993;75(6):950–955. doi: 10.1302/0301-620X.75B6.8245090. [published Online First: 1993/11/01] [DOI] [PubMed] [Google Scholar]
  • 7.McAuley J.P., Harrer M.F., Ammeen D. Outcome of knee arthroplasty in patients with poor preoperative range of motion. Clin Orthop Relat Res. 2002;404:203–207. doi: 10.1097/00003086-200211000-00033. [published Online First: 2002/11/20] [DOI] [PubMed] [Google Scholar]
  • 8.Rand J.A., Trousdale R.T., Ilstrup D.M. Factors affecting the durability of primary total knee prostheses. J Bone Joint Surg Am. 2003;85(2):259–265. doi: 10.2106/00004623-200302000-00012. [published Online First: 2003/02/07] [DOI] [PubMed] [Google Scholar]
  • 9.Jacobs W.C., Clement D.J., Wymenga A.B. Retention versus sacrifice of the posterior cruciate ligament in total knee replacement for treatment of osteoarthritis and rheumatoid arthritis. Cochrane Database Syst Rev. 2005;4 doi: 10.1002/14651858.CD004803.pub2. [published Online First: 2005/10/20] [DOI] [PubMed] [Google Scholar]
  • 10.Bercik M.J., Joshi A., Parvizi J. Posterior cruciate-retaining versus posterior-stabilized total knee arthroplasty: a meta-analysis. J Arthroplast. 2013;28(3):439–444. doi: 10.1016/j.arth.2012.08.008. [published Online First: 2013/02/26] [DOI] [PubMed] [Google Scholar]
  • 11.Sluka K.A., Berkley K.J., O'Connor M.I. Neural and psychosocial contributions to sex differences in knee osteoarthritic pain. Biol Sex Differ. 2012;3(1):26. doi: 10.1186/2042-6410-3-26. [published Online First: 2012/12/19] [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 12.Pan Q., O'Connor M.I., Coutts R.D. Characterization of osteoarthritic human knees indicates potential sex differences. Biol Sex Differ. 2016;7:27. doi: 10.1186/s13293-016-0080-z. [published Online First: 2016/06/04] [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 13.Abdel M.P., Morrey M.E., Jensen M.R. Increased long-term survival of posterior cruciate-retaining versus posterior cruciate-stabilizing total knee replacements. J Bone Joint Surg Am. 2011;93(22):2072–2078. doi: 10.2106/JBJS.J.01143. [published Online First: 2012/01/21] [DOI] [PubMed] [Google Scholar]
  • 14.Cumulative Percent Revisionof Primary Total Kne Replacement with Cement Fixation. National Joint Replacement Registry. Australian Orthopedic Association.; 2014. p. 151. [Google Scholar]
  • 15.National Joint Registry for England, Wales, Northern Ireland and the Isle of Man. 2015. 12th Annual Report. 119,20,21. [Google Scholar]
  • 16.Revision Rates for Cruciate Retaining (CR) vs Posterior Stabilised (PS). New Zealand Joint Registry, Fifteen Year Report January 1999 to December. Vol. 77. 2013. p. 78. [Google Scholar]
  • 17.Morag G., Kulidjian A., Zalzal P. Total knee replacement in previous recipients of fresh osteochondral allograft transplants. J Bone Joint Surg Am. 2006;88(3):541–546. doi: 10.2106/JBJS.D.02816. [published Online First: 2006/03/03] [DOI] [PubMed] [Google Scholar]
  • 18.Mullen J.O. Range of motion following total knee arthroplasty in ankylosed joints. Clin Orthop Relat Res. 1983;179:200–203. [published Online First: 1983/10/01] [PubMed] [Google Scholar]
  • 19.Parsley B.S., Engh G.A., Dwyer K.A. Preoperative flexion. Does it influence postoperative flexion after posterior-cruciate-retaining total knee arthroplasty? Clin Orthop Relat Res. 1992;275:204–210. [published Online First: 1992/02/01] [PubMed] [Google Scholar]
  • 20.Shoji H., Solomonow M., Yoshino S. Factors affecting postoperative flexion in total knee arthroplasty. Orthopedics. 1990;13(6):643–649. doi: 10.3928/0147-7447-19900601-08. [published Online First: 1990/06/01] [DOI] [PubMed] [Google Scholar]
  • 21.Berry D.J., Bozic K.J. Current practice patterns in primary hip and knee arthroplasty among members of the American Association of Hip and Knee Surgeons. J Arthroplast. 2010;25(6 Suppl):2–4. doi: 10.1016/j.arth.2010.04.033. [published Online First: 2010/06/29] [DOI] [PubMed] [Google Scholar]
  • 22.Kettelkamp D.B., Johnson R.J., Smidt G.L. An electrogoniometric study of knee motion in normal gait. J Bone Joint Surg Am. 1970;52(4):775–790. [published Online First: 1970/06/01] [PubMed] [Google Scholar]
  • 23.Laubenthal K.N., Smidt G.L., Kettelkamp D.B. A quantitative analysis of knee motion during activities of daily living. Phys Ther. 1972;52(1):34–43. doi: 10.1093/ptj/52.1.34. [published Online First: 1972/01/01] [DOI] [PubMed] [Google Scholar]
  • 24.Pagnano M.W., Trousdale R.T., Stuart M.J. Rotating platform knees did not improve patellar tracking: a prospective, randomized study of 240 primary total knee arthroplasties. Clin Orthop Relat Res. 2004;428:221–227. [published Online First: 2004/11/10] [PubMed] [Google Scholar]
  • 25.Kellgren J.H.J.M., Ball J. Blackwell Scientific; Oxford: 1963. Atlas of Standard Radiographs. [Google Scholar]
  • 26.Insall J.N., Dorr L.D., Scott R.D. Rationale of the Knee Society clinical rating system. Clin Orthop Relat Res. 1989;248:13–14. [published Online First: 1989/11/01] [PubMed] [Google Scholar]
  • 27.Bellamy N., Campbell J., Stevens J. Validation study of a computerized version of the western ontario and McMaster universities VA3.0 osteoarthritis index. J Rheumatol. 1997;24(12):2413–2415. [published Online First: 1998/02/07] [PubMed] [Google Scholar]
  • 28.Naranja R.J., Jr., Lotke P.A., Pagnano M.W. Total knee arthroplasty in a previously ankylosed or arthrodesed knee. Clin Orthop Relat Res. 1996;331:234–237. doi: 10.1097/00003086-199610000-00033. [published Online First: 1996/10/01] [DOI] [PubMed] [Google Scholar]
  • 29.Kim Y.H., Kim J.S. Does TKA improve functional outcome and range of motion in patients with stiff knees? Clin Orthop Relat Res. 2009;467(5):1348–1354. doi: 10.1007/s11999-008-0445-7. [published Online First: 2008/08/21] [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 30.Debette C., Lustig S., Servien E. Total knee arthroplasty of the stiff knee: three hundred and four cases. Int Orthop. 2014;38(2):285–289. doi: 10.1007/s00264-013-2252-3. [published Online First: 2013/12/24] [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 31.Shah N.A., Patil H.G., Vaishnav V.O. Total knee arthroplasty using subvastus approach in stiff knee: a retrospective analysis of 110 cases. Indian J Orthop. 2016;50(2):166–171. doi: 10.4103/0019-5413.177582. [published Online First: 2016/04/08] [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 32.Massin P., Lautridou C., Cappelli M. Total knee arthroplasty with limitations of flexion. Orthop Traumatol Surg Res. 2009;95(4 Suppl 1):S1–S6. doi: 10.1016/j.otsr.2009.04.002. [published Online First: 2009/05/16] [DOI] [PubMed] [Google Scholar]
  • 33.Cheng K., Ridley D., Bird J. Patients with fixed flexion deformity after total knee arthroplasty do just as well as those without: ten-year prospective data. Int Orthop. 2010;34(5):663–667. doi: 10.1007/s00264-009-0801-6. [published Online First: 2009/05/14] [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 34.Aglietti P., Windsor R.E., Buzzi R. Arthroplasty for the stiff or ankylosed knee. J Arthroplast. 1989;4(1):1–5. doi: 10.1016/s0883-5403(89)80046-4. [published Online First: 1989/01/01] [DOI] [PubMed] [Google Scholar]
  • 35.Cloutier J.M., Sabouret P., Deghrar A. Total knee arthroplasty with retention of both cruciate ligaments. A nine to eleven-year follow-up study. J Bone Joint Surg Am. 1999;81(5):697–702. doi: 10.2106/00004623-199905000-00011. [published Online First: 1999/06/09] [DOI] [PubMed] [Google Scholar]
  • 36.Natarajan G.B., Vijayaraghavan N.V.R. Does preoperative flexion factor influence the postoperative range of motion in total knee arthroplasty. J Orthop Traumatol Rehabil. 2014;7:78–83. [Google Scholar]
  • 37.Bhan S., Malhotra R., Kiran E.K. Comparison of total knee arthroplasty in stiff and ankylosed knees. Clin Orthop Relat Res. 2006;451:87–95. doi: 10.1097/01.blo.0000229313.20760.13. [published Online First: 2006/08/15] [DOI] [PubMed] [Google Scholar]
  • 38.Winemaker M., Rahman W.A., Petruccelli D. Preoperative knee stiffness and total knee arthroplasty outcomes. J Arthroplast. 2012;27(8):1437–1441. doi: 10.1016/j.arth.2011.12.015. [published Online First: 2012/01/31] [DOI] [PubMed] [Google Scholar]
  • 39.Spicer D.D., Curry J.I., Pomeroy D.L. Range of motion after arthroplasty for the stiff osteoarthritic knee. J South Orthop Assoc. 2002;11(4):227–230. [published Online First: 2003/02/25] [PubMed] [Google Scholar]
  • 40.Montgomery W.H., 3rd, Insall J.N., Haas S.B. Primary total knee arthroplasty in stiff and ankylosed knees. Am J Knee Surg. 1998;11(1):20–23. [published Online First: 1998/04/09] [PubMed] [Google Scholar]

Articles from Journal of Orthopaedics are provided here courtesy of Elsevier

RESOURCES