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- DOI 10.18231/j.ijor.2021.005
-
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- Citation
Correlation of knee society score and oxford knee score in patients with moderate to severe osteoarthritis of the knee
- Author Details:
-
Uma Phalswal *
-
Vandna Pandey
-
Ashok Kumar
-
Abhay Elhence
Introduction
Osteoarthritis (OA) is a degenerative, non-inflammatory disease characterized by the formation of osteophytes at the joint surfaces and margins. It causes functional limitation and disability. Osteoarthritis most commonly affects the synovial joints, though it can affect any joint, it is more common in weight-bearing joints like the knee, hip, spine, etc. Among the joints, the knee is most commonly affected by Osteoarthritis as the knee is a weight-bearing joint and crucial for function.[1] More than half of the population have Bilateral Knee Osteoarthritis. [2]
The prevalence of knee OA in adults ranges from 4 to 30 percent, depending on age, gender, and physical activity level.[3] Knee osteoarthritis is most frequent in elderly people and causes a deterioration in the quality of life.[4] It leads to a significant problem for individuals and society. [5]
Joint discomfort, limited range of motion, quadriceps muscle weakness, and stiffness are the most typical symptoms of knee osteoarthritis. The pain is poorly localized and has a dull aching quality to it. The patient experiences modest swelling of the knee joint and stiffness in the morning, which reduces later in the day after moderate movement. High-grade osteoarthritis can cause genu varus deformity.[1] Patients with knee osteoarthritis have reduced quadriceps muscle strength by 10-60% as compared to healthy persons.[4]
Early-stage osteoarthritis is treated conservatively with physiotherapy, alteration of daily living activities, analgesics, weight loss, and viscosupplements. The primary goal is to relieve pain and inflammation, enhance range of motion, and develop muscle strength. However, advanced stages of knee osteoarthritis are treated with the most common procedure, complete knee replacement.[1]
Knee Society Score (KSS) was designed in 1989 as a simple but objective scoring system to measure the patient's functional capacities of the Knee. KSS is the most often used approach for reporting outcomes following total and partial knee arthroplasty. It was separated into two parts: a Knee score and a Function score. Both components of the Knee Society Score total of 100 points. The clinical KSS assesses pain, range of motion, and knee joint stability.[6]
The Oxford Knee Score (OKS), a 12 item self-administered questionnaire that items based on the daily activities of patients.[7] Oxford Knee Score covers the assessment of pain and function of the knee associated with osteoarthritis.[8]
In India, around 80% of the population have osteoarthritis among the patients who complained of knee pain, out of which around 20% reported incapability in daily activities. Nearly 40% population of more than 70 years have osteoarthritis, of which around 2% have a disability and severe knee pain.[9]
This study was conducted since the diagnosis of OA is currently based on X-ray data and clinical complaints of the patients.[10] Functional limits of knee OA are usually neglected while diagnosing patients. The Knee Society Score and the Oxford Knee Score are useful in determining the functional limitations encountered in knee osteoarthritis patients.
Materials and Methods
At the All India Institute of Medical Sciences (AIIMS) in Jodhpur, Rajasthan, an Observational (Correlational) study was undertaken on a group of 100 patients. This study comprised patients with moderate to severe Knee Osteoarthritis, aged 40 and over, who visited the outpatient department (OPD) of Orthopedics at AIIMS, Jodhpur, Rajasthan. In this investigation, a non-probability purposive sampling methodology was applied and data was collected in October to December 2018.
Sample size calculation
The prevalence of knee osteoarthritis in India was 28.7%, according to Chandra Prakash pal et al.[11] The sample size was estimated using the below method with a 95% confidence interval and a 10% precision.
N= Z2 P (1-P) / C2
N= (1.96)2 X 28.7 X71.6 / 102 = 78.94 ≈79
However, the researcher chose 100 patients based on the availability of samples during the data collection period.
Inclusion criteria
Patients who agreed to take part in the research.
In X-ray, the patient had moderate to severe Knee Osteoarthritis.
Exclusion criteria
Patients who have had previous knee surgery.
Patients with any type of neurologic or mental illness.
Patients who are paralyzed or paraplegic.
Rheumatoid arthritis patients, hereditary bone and joint disease patients.
Data collection tools
A Personal variable data tool was developed, KSS and OKS standardized tools were used.
Part A- Personal variable Data Such as Name/ID, Age, Gender, Body Mass Index grading, Diet pattern, Knee affected, Compliance in Physiotherapy and previous treatment.
Part B
1) Knee Society Score (KSS) - Knee Society Score is a simple scoring system to rate the patient’s knee and function abilities in Knee Osteoarthritis patients. Knee Society Score has two components. [12]
a) Knee score (KS)
b) Function score (FS).
Both components have 0-100 points. It is a health care professional score.
2) Oxford Knee Score (OKS)-The Oxford Knee Score (OKS) is a 12-item patient-reported outcome questionnaire to assess function and pain in Knee Osteoarthritis patients. It has two components-
a) Pain component scale (PCS)
b) Function component scale (FCS).
PCS consists of 5 items and FCS consists of 7 items. Completion and scoring of the OKS are simple. The OKS is patient-administered and should take about 5 minutes to complete, and responses are based on symptoms in the preceding last 4 weeks. [13]
OKS was a standardized tool and permission to use OKS was taken from the authorized person.
Ethical considerations
The Institutional Ethical Committee of AIIMS Jodhpur provided ethical approval. AIIMS/IEC/2018/527 is the certificate reference number.
Procedure for data collection
Data for the study was obtained after obtaining formal permission to perform it. Patients with knee pain had their X-rays done. Following the diagnosis of osteoarthritis, the severity of the condition is determined using X-ray findings. Patients were informed about the study and guaranteed that their information would be kept private. Patients with moderate to severe pain gave their consent. All consenting patients' Knee Society Scores were recorded. Interviewed the patients and noted their Oxford knee score responses. The time it takes to complete the questionnaire is estimated to be between 15-20 minutes.
Results
Most of the patients in this study were between the ages of 56-70 years, and nearly half of them (42%) had Bilateral Knee Osteoarthritis. More than half of the patients (56%) were female, with 44 percent being male. Half of the patients (51%) had an excessively high BMI, and the majority of the patients (76%) were receiving OA symptomatic treatment such as analgesics and massage.([Table 1])
Following the first part of the KSS study, we discovered that the majority of the patients (82.4%) had poor knee condition, 16.9% had fair knee condition, and only 0.7 percent had good knee condition. Knee Society Score is 49.07±1.06 on average. ([Table 2])
The second part, the Knee Function Score showed that one-third of the patients (35.2%) had a fair Knee condition, whereas 27.5 percent had a poor Knee condition, 31.7 percent had a good Knee condition, and 5.6 percent had excellent Knee condition. The mean knee Function score is 59.82±1.38. ([Table 3])
Following an OKS analysis, we discovered that the majority of the patients (46.5%) had moderate to severe Knee Osteoarthritis, with 26.8% having severe Knee OA and 26.8% having mild to moderate knee OA. The Oxford Knee Score average is 22.69±7.09. ([Table 4])
The Spearman rho (ρ) correlation calculation is used to determine whether the two scores are correlated or not. The correlation between the Oxford Knee Score and the Knee Society Score is 0.66. The Oxford Knee Score and the Knee Society Score had a moderately favorable connection. According to the findings, at a modest level, both clinical ratings have roughly the same effect and both equally essential in the assessment and treatment of Knee Osteoarthritis patients. ([Table 5])
|
S.No |
Personal Variables |
f |
|
1. |
Age (years) |
|
|
a. 40-55 |
35 |
|
|
b. 56-70 |
54 |
|
|
c. 71-85 |
11 |
|
|
2. |
Gender |
|
|
a. Male |
44 |
|
|
b. Female |
56 |
|
|
3. |
Body Mass Index (BMI) grading- |
|
|
a. <18.5 (underweight) |
2 |
|
|
b. 18.5- 24.9 (normal) |
28 |
|
|
c. 25.0-<30 (overweight) |
51 |
|
|
d. >30 (obese) |
19 |
|
|
4. |
Diet pattern- |
|
|
a. Vegetarian |
81 |
|
|
b. Non vegetarian |
19 |
|
|
5. |
Occupation |
|
|
a. Homemaker |
55 |
|
|
b. Agriculture |
11 |
|
|
c. Private service |
9 |
|
|
d. Government service |
9 16 |
|
|
e. Unemployed |
||
|
6. |
Knee affected- |
|
|
a. Right |
30 |
|
|
b. Left |
28 |
|
|
c. Both |
42 |
|
|
7. |
Compliance in physiotherapy- |
|
|
a. Yes (regular) |
34 |
|
|
b. Yes(sometimes) |
27 |
|
|
c. No |
39 |
|
|
8 |
Previous treatment of knee osteoarthritis- |
|
|
a. Yes |
76 |
|
|
b. No |
24 |
|
|
9. |
Any other health problems- |
|
|
a. Yes |
42 |
|
|
b. No |
58 |
|
S.No |
Grading |
f (%) |
Mean ± SD |
|
1 |
Excellent (80-100) |
Nil |
49.07±1.06 |
|
2 |
Good (70-79) |
01 (0.7) |
|
|
3 |
Fair (60-69) |
24 (16.9) |
|
|
4 |
Poor (Below 60) |
117 (82.4) |
|
S.No |
Grading |
f (%) |
Mean ± SD |
|
1 |
Excellent (80-100) |
8 (5.6) |
59.82±1.38 |
|
2 |
Good (70-79) |
45 (31.7) |
|
|
3 |
Fair (60-69) |
50(35.2) |
|
|
4 |
Poor (Below 60) |
39(27.5) |
|
S.No |
Grading |
f (%) |
Mean ± SD |
|
1 |
Satisfactory Knee (40 to 48) |
Nil |
24.69±7.09 |
|
2 |
Mild to moderate OA (30 to 39) |
38 (26.8) |
|
|
3 |
Moderate to Severe OA (20 to 29) |
66 (46.5) |
|
|
4 |
Severe OA (0 to 19) |
38 (26.8) |
|
Score/ grading |
Spearmen’s rho(ρ) |
|
Knee Society Score (KS) and Oxford Knee Score (OKS) |
0.65 |
|
Complete Knee Society Score (KSS) and Oxford Knee Score (OKS) |
0.66 |
|
S.No |
Variables |
Knee Society Score |
X2 |
df |
P-value |
||
|
Good (2) |
Fair (3) |
Poor (4) |
|
|
|
||
|
1. |
Age 40-55 |
0 |
10 |
38 |
6.17NS# |
4 |
0.142 |
|
56-70 |
1 |
14 |
61 |
||||
|
71-85 |
0 |
0 |
18 |
||||
|
2. |
Gender Male |
1 |
14 |
48 |
3.58NS# |
2 |
0.117 |
|
Female |
0 |
10 |
69 |
||||
|
3. |
BMI <18.5 |
0 |
2 |
0 |
11.86NS# |
6 |
0.063 |
|
18.6- 24.9 |
1 |
7 |
32 |
||||
|
25.0-<30 |
0 |
12 |
62 |
||||
|
>30 |
0 |
3 |
23 |
||||
|
4. |
Diet pattern Vegetarian |
1 |
19 |
96 |
0.69NS# |
2 |
0.816 |
|
Non vegetarian |
0 |
5 |
21 |
||||
|
5. |
Occupation Homemaker |
0 |
13 |
62 |
18.02*# |
8 |
0.007 |
|
Agriculture |
1 |
6 |
9 |
||||
|
Private job |
0 |
4 |
10 |
||||
|
Govt. job |
0 |
0 |
14 |
||||
|
Unemployed |
0 |
1 |
22 |
||||
|
6. |
Physiotherapy Regular |
0 |
17 |
31 |
18.02*# |
4 |
0.000 |
|
Sometimes |
1 |
3 |
35 |
||||
|
Never |
0 |
4 |
51 |
||||
|
7. |
Treatment Yes |
1 |
19 |
92 |
0.47NS# |
2 |
1.00 |
|
No |
0 |
5 |
25 |
|
Variables |
Knee Function Score |
X2 |
df |
P value |
|||
|
Excellent (1) |
Good(2) |
Fair(3) |
Poor(4) |
||||
|
Age |
|
|
|
|
|
|
|
|
40-55 |
5 |
19 |
20 |
4 |
18.74*# |
6 |
0.003 |
|
56-70 |
3 |
23 |
25 |
25 |
|||
|
71-85 |
0 |
3 |
5 |
10 |
|||
|
Gender |
|
|
|
|
|
|
|
|
Male |
3 |
25 |
19 |
16 |
3.43NS# |
3 |
0.330 |
|
Female |
5 |
20 |
31 |
23 |
|||
|
BMI |
|
|
|
|
|
|
|
|
<18.5 |
2 |
0 |
0 |
0 |
25.83*# |
9 |
0.001 |
|
18.6- 24.9 |
5 |
17 |
14 |
4 |
|||
|
25.0-<30 |
1 |
21 |
26 |
26 |
|||
|
>30 |
0 |
7 |
10 |
9 |
|||
|
Diet pattern |
|
|
|
|
|
|
|
|
Vegetarian |
4 |
35 |
41 |
36 |
8.77* |
3 |
0.032 |
|
Non vegetarian |
4 |
10 |
9 |
3 |
|||
|
Occupation |
|
|
|
|
|
|
|
|
Home maker |
7 |
17 |
28 |
23 |
24.22*# |
12 |
0.008 |
|
Agriculture |
1 |
11 |
3 |
1 |
|||
|
Private service |
0 |
7 |
3 |
4 |
|||
|
Govt. service |
0 |
4 |
9 |
1 |
|||
|
Unemployed |
0 |
6 |
7 |
10 |
|||
|
Physiotherapy |
|
|
|
|
|
|
|
|
Regular |
5 |
22 |
12 |
9 |
17.13*# |
6 |
0.004 |
|
Sometimes |
3 |
6 |
19 |
11 |
|||
|
Never |
0 |
17 |
19 |
19 |
|||
|
Treatment |
|
|
|
|
|
|
|
|
Yes |
7 |
39 |
36 |
30 |
3.50NS |
3 |
0.320 |
|
No |
1 |
6 |
14 |
9 |
|
S.No |
Variables |
Oxford Knee Score |
X2 |
Df |
P-value |
||
|
Mild to moderate OA (2) |
Moderate to severe OA (3) |
Severe OA (4) |
|
|
|
||
|
1 |
Age 40-55 |
14 |
26 |
8 |
9.55*# |
4 |
0.046 |
|
56-70 |
22 |
34 |
20 |
||||
|
71-85 |
2 |
6 |
10 |
||||
|
2 |
Gender Male |
17 |
28 |
18 |
0.24NS |
2 |
0.886 |
|
Female |
21 |
38 |
20 |
||||
|
3 |
BMI grading <18.5 |
1 |
1 |
0 |
7.02NS# |
6 |
0.267 |
|
18.6- 24.9 |
10 |
23 |
7 |
||||
|
25.0-<30 |
23 |
29 |
22 |
||||
|
>30 |
4 |
13 |
9 |
||||
|
4 |
Diet pattern Vegetarian |
30 |
53 |
33 |
0.95NS |
2 |
0.622 |
|
Non vegetarian |
8 |
13 |
5 |
||||
|
5 |
Occupation Homemaker |
23 |
34 |
18 |
6.65NS# |
8 |
0.579 |
|
Agriculture |
4 |
9 |
3 |
||||
|
Private job |
5 |
4 |
5 |
||||
|
Govt. job |
1 |
8 |
5 |
||||
|
Unemployed |
5 |
11 |
7 |
||||
|
6 |
Physiotherapy Regular |
16 |
24 |
8 |
5.46NS |
4 |
0.243 |
|
Sometimes |
10 |
19 |
10 |
||||
|
Never |
12 |
23 |
20 |
||||
|
7 |
Treatment Yes |
29 |
54 |
29 |
0.64NS |
2 |
0.725 |
|
No |
9 |
12 |
9 |
The chi-square test was used to determine the association of the Knee Society Score with selected personal variables, and it was discovered that the severity of Knee Osteoarthritis in the Knee Society Score was substantially correlated with occupation and physiotherapy at the 0.05 level of significance ([Table 6]). Whereas, Severity of Knee Osteoarthritis in Knee Function Score was shown to be substantially correlated with age, food pattern, BMI, occupation, and physiotherapy ([Table 7]). Oxford Knee Score was shown to be substantially correlated only with age at the 0.05 level of significance. ([Table 8])
Discussion
Knee osteoarthritis is becoming the largest cause of disability in the world. Obesity and population aging are contributing to a rise in Knee Osteoarthritis worldwide. It is a bone cartilage wear and tears disease. Knee osteoarthritis progresses over 10 to 15 years, interfering with daily activities. Knee OA treatment aims to alleviate pain, enhance the quality of life, and enhance knee function.[14]
The present study showed that more than half of the (56%) patients were female. A study conducted by Chandra pal et al.[11] shown that females had more prevalence (31.6%) as compared to males (28.1%).
Half of the patients in this research (51%) were overweight (BMI 25 -30). Obese patients had a higher risk of knee osteoarthritis, according to a study conducted by Silverwood V. et al.[15] Weight loss is a major goal in the prevention of knee osteoarthritis. According to the Chandra pal et al[11] study, the prevalence of knee OA increases as the BMI rises.
Knee Osteoarthritis in Oxford Knee Score with mean score 24.69±7.09. A study conducted by Petersen et al (2017)[16] shown approx the same result, the mean score of OKS is 20.3±6.9. Minor difference in mean score with this study is due to the involvement of moderate and severe knee osteoarthritis while Petersen et al only include severe knee osteoarthritis.
Oxford Knee Score and Knee Society Score had a moderate positive correlation (r= 0.66). A similar finding of correlation(r=0.68, p < 0.001) between KSS and OKS has been reported by Maempel JF et al (2015).[17]
Van Hove RP et al. (2016)[18] reported high post-operative correlation between OKS and KSS (r = 0.80, p < 0.001). Moonot P et al. (2009)[19] reported a negative correlation of -0.64 (P < .0001) between the OKS and KSS at mid-term follow up (negative correlation due to previous reverse scoring of OKS).
Whereas a study conducted by Radhakrishna A. M et al (2017)[20] in Bengaluru India. This study includes 60 OA knees with pre-op and post-op knee clinical scores and knee functional scores. The average pro op knee score is 24.7 and at 1 year of follow-up average knee, the score is 89.9. The average pre-op knee functional score is 41.2 and the post-op score is 87.8. Another study conducted by Sancheti KH et al.[21] shown the pre-op mean score of KSS is 39.4 and functional scores 46.7. The difference in pre-op mean score is due to this study included only severe knee osteoarthritis for surgery and my study includes both moderate and severe knee osteoarthritis.
Health care observed score (KSS) and patient-reported score (OKS) both had a moderate level of correlation so when deciding the treatment of knee osteoarthritis both scores should be considered for better and effective treatment.
Researchers also discovered that only 34% of patients adhered to physiotherapy regularly and that the majority of patients (66%) did not understand the benefits of physiotherapy and chose to take analgesics to ease knee pain.
Conclusions
Knee osteoarthritis is the most common musculoskeletal problem in the middle age or older age population. There are approximately 100 million population of more than 45 years old suffering from Osteoarthritis of the knee. The study was conducted to assess the correlation between health care professional score (KSS) and patients' reported outcomes (OKS). There is a moderate positive correlation (0.66) between KSS and OKS. Analysis showed that KSS and OKS present the same results to some extent. After a diagnosis of knee OA with the help of X-Ray and clinical symptoms, this functional score should also be considered for better management of the condition. Personal variables like age, BMI, occupation, and physiotherapy show association with KSS and OKS scores. The study concluded that for better and effective treatment X-ray, Knee Society Scoring, and Oxford Knee Score of the Knee is essential.
Conflict of Interest
The authors declare that there are no conflicts of interest in this paper.
Source of Funding
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
References
- J Ebnezar. Textbook of Orthopaedics. 4th Edn. 2010. [Google Scholar]
- D Hernández-Vaquero, J Manuel Fernández-Carreira. Relationship between radiological grading and clinical status in knee osteoarthritis. a multicentric study. BMC Musculoskeletal Disord 2012. [Google Scholar] [Crossref]
- PP Flores-Garza, ÓA García-Espinoza, K Salas-Longoria, Ó Salas-Fraire. Association between ischiotibial muscle flexibility, functional capacity and pain in patients with knee osteoarthritis. Med Universitaria 2017. [Google Scholar] [Crossref]
- L Congying, W Qiaoqin, Z Weijiao, F Xiaolin, S Shang. Factor associated with balance function in patients with knee osteoarthritis: a multicenteric review. Int J Nurs Sci 2017. [Google Scholar] [Crossref]
- J Martín-Fernández, R Garcia-Maroto, F J Sanchez-Jimenez. Validation of the Spanish version of the Oxford knee score and assessment of its utility to characterize quality of life of patients suffering from knee osteoarthritis: a multicentric study. Health Qual Life Outcomes 2017. [Google Scholar] [Crossref]
- A L Martimbianco, F R Calabrese, L A Iha, M Petrilli, O Lira Neto, M Carneiro Filho, . Reliability of the American Knee Society Score (AKSS). Acta Ortop Bras 2012. [Google Scholar]
- F D Naal. Short communication the 12 item oxford knee score: cross cultural adaptation into german and assessment of its psychometric properties in patients with osteoarthritis of the knee. Osteoarthritis Res Soc Int 2009. [Google Scholar] [Crossref]
- KK Harris, J Dawson, LD Jones, DJ Beard, AJ Price. Extending the use of PROMs in the NHS—using the Oxford Knee Score in patients undergoing non-operative management for knee osteoarthritis: a validation study. BMJ Open 2013. [Google Scholar] [Crossref]
- C Azad, A Singh, P Pandey, M Singh, Chaudhary P, N Tia. Osteoarthritis in india: an epidemiological aspect. Int J Recent Scic Res 2017. [Google Scholar]
- O Serban, M Porojan, M Deac, F Cozma, C Solomon, M Lehghel. Pain in bilateral knee osteoarthritis – correlations between clinical examination, radiological, and ultrasonographical findings.. Med Ultrason 2016. [Google Scholar] [Crossref]
- CP Pal, P Singh, S Chaturvedi, KK Pruthi, A Vij. Epidemiology of knee osteoarthritis in India and related factors. Indian J Orthop 2016. [Google Scholar] [Crossref]
- MM Dowsey, PF Choong. The Utility of Outcome Measures in Total Knee Replacement Surgery. Int J Rheumatol 2013. [Google Scholar] [Crossref]
- KIA Reddy, LR Johnston, W Wang, RJ Abboud. Does the Oxford Knee Score Complement, Concur, or Contradict the American Knee Society Score?. J Arthroplasty 2011. [Google Scholar] [Crossref]
- M J Lespasio, N S Piuzzi, M E Husni, G F Muschler, A Guarino, M A Mont. Knee Osteoarthritis: A Primer. Perm J 2017. [Google Scholar] [Crossref]
- V Silverwood, M Blagojevic-Bucknall, C Jinks, J L Jordan, J Protheroe, K P Jordan. Current evidence on risk factors for knee osteoarthritis in older adults: a systematic review and meta-analysis. Osteoarthritis Cartilage 2015. [Google Scholar]
- CL Petersen, JB Kjærsgaard, N Kjærgaard, MU Jensen, MB Laursen. Thresholds for Oxford Knee Score after total knee replacement surgery: a novel approach to post-operative evaluation. J Orthop Surg Res 2017. [Google Scholar] [Crossref]
- JF Maempel, ND Clement, IJ Brenkel, PJ Walmsley. Validation of a prediction model that allows direct comparison of the Oxford Knee Score and American Knee Society clinical rating system. Bone Joint J 2015. [Google Scholar] [Crossref]
- RP van Hove, RM Brohet, BJ van Royen, PA Nolte. High correlation of the Oxford Knee Score with postoperative pain, but not with performance-based functioning. Knee Surg Sports Traumatol Arthrosc 2016. [Google Scholar] [Crossref]
- P Moonot, G Medalla, D Matthews, Y Kalairajah, R Field. Correlation Between the Oxford Knee and American Knee Society Scores at Mid-Term Follow-Up. J Knee Surg 2009. [Google Scholar] [Crossref]
- AM Radhakrishna, S Shivananda, S Girish. A study of clinical and functional outcome of primary total knee arthroplasty using posterior cruciate substitute design. Int J Res Orthop 2017. [Google Scholar] [Crossref]
- KH Sancheti, NS Laud, H Bhende, G Reddy, N Pramod, JN Mani. The INDUS knee prosthesis - Prospective multicentric trial of a posteriorly stabilized high-flex design: 2 years follow-up. Indian J Orthop 2009. [Google Scholar] [Crossref]