International Journal of Research in Orthopaedics Phalswal U et al. Int J Res Orthop. 2021 May;7(3):606-610 http://www.ijoro.org
DOI: https://dx.doi.org/10.18203/issn.2455-4510.IntJResOrthop20211617
Original Research Article
Correlation of Ahlback grading and knee society score in patients
with moderate to severe osteoarthritis of the knee
Uma Phalswal1*, Vandna Pandey2, Ashok Kumar2, Abhay Elhence3
1Department of Nursing, All India Institute of Medical Sciences, Bhopal, Madhya Pradesh, India 2College of Nursing, 3Department of Orthopaedics, All India Institute of Medical Sciences, Jodhpur, Rajasthan, India Received: 02 February 2021 Accepted: 11 March 2021 *Correspondence: Uma Phalswal, E-mail: Phalswaluma2828@gmail.com Copyright: © the author(s), publisher and licensee Medip Academy. This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
ABSTRACT Background: Knee osteoarthritis (OA) is a most common rheumatological disorder that causes functional limitation and disability. The most common problem in knee OA are joint pain and stiffness. It will lead to decreased quality of life and it have a serious economic burden on any country due to effect of disability and treatment. Methods: A correlational study was conducted to find out correlation between Ahlback grading and knee society score (KSS) on a sample of 100 moderate to severe knee OA patients and 142 OA knees. Data was collected at orthopedics OPD, for a period of 3 months by purposive sampling. Results: On evaluation, mean age of the participants was 60.19±1.01. Out of 100 patients, 42 patients had bilateral knee OA, therefore total 142 knees included in the analysis. More than half (51%) participants were overweight. Only 34% subjects had compliament to physiotherapy. Around 76% subjects taking analgesics and massage therapy to reduce knee pain. Maximum 82.4% subjects had a poor knee condition in KSS and mean score is 49.07±1.06. Ahlback grading in X-ray had negative correlation -0.610 with KSS. Hence it is evaluated, both the scales have approximately same result as it is analyzed that both scales are moderately correlated. There is significant association of age, occupation and physiotherapy with Ahlback grading followed with KSS significant associated with BMI, occupation and physiotherapy. Conclusions: The study concluded that there is a moderate correlation found between Ahlback X-ray grading and knee society scoring. X-ray and knee society scoring (clinical evaluation) both are essential for effective treatment of OA. Keywords: Ahlback grading, KSS, Osteoarthritis, Knee
INTRODUCTION
Knee OA is a degenerative, non-inflammatory joint disease characterized by the breakdown of articular cartilage and formation of new bone (osteophytes) at the joint surfaces and margins.1 OA leads to decreased quality of life and it is most common in older persons. Knee OA have a serious economic burden on any country due to effect of disability and treatment.2 Severely disabled people of OA has difficulty in performing the activities of daily living due to muscle spasm.3 The prevalence of knee OA estimated from 4 to 30% in adults, depends on age, gender and physical activity of
the person. The high susceptibility of knee OA is mainly due to joint loading, which makes it susceptible to wear and tear pressure.3 More than 50% population have bilateral knee OA.1 Ahlback is radiographic grading of severity of knee OA.4 KSS is an objective scoring system to rate the patient’s functional abilities of the knee.5 In current practice, diagnosis of knee OA is done by using X-ray findings and patient clinical symptoms. Radiographic evidence of osteoarthritis in the knee joint is the most common manifestation of pathology in this joint and a different grading system is used to grade the severity of OA such as Kellgren and Lawrence system and the Ahlback classification. In this study Ahlback
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classification is used because this classification is widely used to assess the degree of involvement, monitor disease progression and assist in surgical planning of treatment.4
Most of the time functional limitation of knee OA is not taken into consideration while making a diagnosis. KSS helps to find out the functional limitation seen in knee OA patients. It helps in better evaluation and management of knee OA.
METHODS
An observational (correlational) study was conducted on a sample of 100 moderate to severe knee OA patients, age 40 years and above, attending the OPD of orthopedic included in this study. Non probability purposive sampling technique was used in this study and data was collected between October to December 2018.
Sample size calculation
According to Chandra PP et al the prevalence of knee OA in India was 28.7%.6 Keeping 95% confidence interval and 10% precision, the sample size calculated using the formula,
𝑍2 𝑃 (1−𝑃)
N=
𝐶2,
(1.96)2×28.7×71.6
N=
102=78.94 ≈79
But the researcher recruited 100 subjects as per the availability of samples during the period of data collection considering improvising the level of precision. So, the final sample size was 100 patients and total 142 OA knees because 42 patients had bilateral knee OA.
Inclusion criteria
Patients who were willing to participate in the study and patients who had moderate to severe knee OA as per Ahlback scoring on X-ray were included in this study.
Exclusion criteria
Patients with any previous surgery of knee, patients with any neurologic problems and mental disorders, patients with paraplegia and paralysis, patients with rheumatic diseases, genetics, bone and joint disease were excluded from this study.
Data collection tools
The demographic data tool was developed and Ahlback, KSS standardized tool was used.
Part A
Personal variable data such as name/ID, age, gender, BMI grading, diet pattern, Ahlback classification of knee, knee affected, compliament to physiotherapy and previous treatment.
Part B
Ahlback grading
Ahlback grading is a standardized tool to assess the severity of knee OA by X-ray.
The Ahlback radiographic classification of knee OA was originally proposed by Ahlback et al in 1968 and modified by Keyes et al in 1992. It is subdivided into five grades from I to V and it is widely used in clinical practice. This classification is widely used to assess the degree of involvement, monitor disease progression and assist in surgical planning of treatment.7
According to Ahlback grading, knee OA classified as; grade1 joint space narrowing (less than 3 mm), grade 2 joint space obliteration, grade 3 bone defects/loss (0-5 mm), grade 4 moderate bone defects/loss (5-10 mm), grade 5 severe bone defects/loss (more than 10 mm).
KSS
KSS is a standardized tool to rate the patient’s knee and functional abilities in knee OA patients.8 KSS has two components; knee score (KS), function score (FS). Both components have 0-100 points.
Procedure for data collection
After taking formal permission to conduct the study, data for the study was collected. X-ray of patients with knee pain was taken. After diagnosis of OA, Ahlback grading of knee osteoarthritis was done on the basis of severity on X-ray. Consenting patients with moderate to severe knee OA taken for KSS data collection. Participants were explained regarding the study and assured of the confidentiality of information. Physical assessment of the knee done and record the KSS. Approximately time taken to complete the questionnaire will be ranging from 5-10 minutes.
RESULTS
In the present study maximum number of patients in the age group of 56-70 years of age and nearly half (42%) patients had bilateral knee OA (Table 1).
Table 2 shows that most of the patients (47.2%) had grade 3 knee OA, followed by 29.6% patients had grade 4 knee OA, 16.9% patients had grade 2 knee OA and only 6.3% patients had grade 5 OA knee.
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Phalswal U et al. Int J Res Orthop. 2021 May;7(3):606-610
Table 3 shows that most of the patients (82.4%) had poor knee condition, followed by 16.9% patients had the fair knee condition and only 0.7% patients had good knee condition. The mean of KSS is 49.07±1.06.
Table 4 depicts that one third (35.2%) of patients had the fair knee condition followed with 27.5% patients who had poor knee condition. 31.7% patients had a good knee condition and 5.6% patients had excellent knee condition. The mean of knee function score is 59.82±1.38.
Table 1: Frequency and percentage distribution of knee OA patients in terms of personal variables.
Table 2: Frequency and percentage OA patients as per Ahlback grading (N=142#).
#142 OA knees of 100 patients.
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Phalswal U et al. Int J Res Orthop. 2021 May;7(3):606-610
Table 3: Frequency and percentage of knee OA patients as per grading of KSS (N=142#).
#142 OA knees of 100 Patients, KSS minimum score is 0 and maximum score is 100.
Table 4: Frequency and percentage of knee OA patients as per grading of knee function score (N=142#).
#142 OA knees of 100 patients KFS minimum score is 0 and maximum score is 100.
Table 5: Correlation between Ahlback grading, KSS and KFS of knee OA (N=142#).
DISCUSSION
A study conducted by Radhakrishna AM et al in 2017 in Bengaluru India included 60 OA knees with pre-op and post-op knee clinical score and knee functional score.9 Average pre-op knee score is 24.7 and at 1 year of follow-up average knee score is 89.9. Average pre-op KFS is 41.2 and the post-op score is 87.8. Another study conducted by Sancheti KH et al shown the pre op mean score of KSS is 39.4 and KFS is 46.7.10 Difference in pre- op mean score is due to study included only severe knee OA for surgery and this study includes both moderate and severe knee OA.
Correlation is calculated with Spearman rho (ρ) correlation formula. Correlation between Ahlback grading of knee OA and KS is -0.55 followed by -0.53 between Ahlback and KFS. Correlation between Ahlback and complete KSS (both clinical and functional score) is - 0.61 with 95% confidence interval and at the 0.05 level of significance (Table 5).
There is a moderate negative correlation (-0.61) found between Ahlback X-ray grading and KSS. The correlation is negative because there is reverse scoring of severity in both scales, hence it is evaluated that Ahlback grading (X- ray) and clinical score (KSS) have approximately same results. KSS also assess the severity of knee OA as per Ahlback grading.
Anatomical defect of knee OA and functional defects both had a fair correlation hence X-ray and the clinical evaluation (KSS) both are essential for the better and
effective treatment of knee OA because these two gradings are moderately correlated not strongly correlated.
There were studies conducted to find correlation between Ahlback grading and other orthopaedics scores (like WOMAC, SF -36, HSS) but there is no study found on correlation between Ahlback grading and KSS score.
Association between Ahlback grading and selected personal variables calculated with chi square test and it is shown that severity of knee OA in Ahlback grading by X- ray was found to significantly associate with age, occupation and physiotherapy at 0.05 level of significance. Whereas chi-square values computed for Ahlback grading with gender, BMI, diet pattern and treatment were found statistically not significant at 0.05 level of significance.
Severity of knee OA in knee society score was found to significantly associate with occupation and physiotherapy at 0.05 level of significance. Severity of knee OA in knee function score was found to significantly associate with age, diet pattern, BMI, occupation and physiotherapy at 0.05 level of significance. Whereas chi-square values computed for knee function score with gender and treatment were found statistically not significant at 0.05 level of significance.
CONCLUSION
Knee OA is the most common musculoskeletal problem in middle age or older age population. There are
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approximately 100 million population of more than 45 years old suffering from OA of the knee. Study conducted to assess correlation between X-ray (Ahlback grading), health care professional score (KSS). Study conducted at orthopaedics OPD, of knee OA patients, age 40 years or above. There is a moderate negative correlation (-0.61) between Ahlback grading and KSS.
Analysis showed that Ahlback and KSS presents the same results. Personal variables like age, BMI, occupation and physiotherapy shows association with Ahlback and KSS scores. Study concluded that for better and effective treatment, X-ray and KSS of the knee is essential.
ACKNOWLEDGEMENTS
I would like to thank Dr. Raj Rani, principal of college of nursing, AIIMS, Jodhpur for her support, valuable suggestions and for permitting me to conduct this study. I would like to thank the ethical committee of AIIMS, for granting the approval of my study.
I extend my gratitude towards all the study participants, for their co-operation and devotion of time during the data collection period, without which, it might not have been possible to complete this project.
Funding: No funding sources Conflict of interest: None declared Ethical approval: The study was approved by the institutional ethics committee
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Cite this article as: Phalswal U, Pandey V, Kumar A, Elhence A. Correlation of Ahlback grading and knee society score in patients with moderate to severe osteoarthritis of the knee. Int J Res Orthop 2021;7:606-10.
International Journal of Research in Orthopaedics | May-June 2021 | Vol 7 | Issue 3 Page 610