Traction for hip osteoarthritis
Abstract
This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:
To compare the effectiveness and harms of traction interventions in patients with hip osteoarthritis to other interventions or no intervention on pain, activities of daily living, range of motion and quality of life.
Background
Osteoarthritis (OA), the most frequent joint disorder in the world today, represents a complex disease process in which a combination of systemic and local mechanisms results in pathological and radiological changes (Brandt 2003). Scott (Scott 2003) estimated that 20% of the population more than 60 years of age has symptoms of OA. A report from WHO shows that OA in 1990 was on the top‐ten list of the most common diseases in the world (Lopez 1998). In the period from 1990 to 2020 it is expected that the number of people more than 50 years old will be doubled, and this will probably give a marked increase in people with OA (Lopez 1998; Lohmander 2002). Prevalence of osteoarthritis of the hip ranged from 4.4% to 5.3% in subjects 60 years and older in a study of 4151 subjects in Sweden (Jacobsen 2004).
OA is a chronic disease characterised by joint pain, tenderness, limitation of movement, crepitus, occasional effusion, and variable degrees of local inflammation, but without systemic effects (Brandt 1986). The disease process not only affects the articular cartilage, but involves the entire joint, including the subchondral bone, ligaments, capsule, synovial membrane, and periarticular muscles (Flores 2003). The characteristics of the disease are thickening of the joint capsule, progressive cartilage loss, and osteophyte formation, leading to functional impairments (Oliveria 1995; Sowers 2000). OA accounts for more problems in walking and climbing stairs than any other musculoskeletal disease (Guccione 1994). Other functional impairments are, for example, experienced during putting on shoes and trousers. The American Rheumatology Association (ARA) has published clinical classification criteria for OA of the hip (Altman 1991). They recommend using history, physical examination, laboratory and radiographic findings. The criteria include pain in the hip, reduced range of motion (internal rotation < 15º and hip flexion < 115º), pain associated with internal rotation, and morning stiffness of the hip for 60 minutes or less. Criteria found by radiographic examination are femoral or acetabular osteophytes, or both, and joint space narrowing.
Current therapies for OA are directed towards controlling symptoms, maintaining function and reducing further joint damage. Dieppe and Lohmander (Dieppe 2005) suggest a sequential pyramidal approach to disease management. Lifestyle alterations, exercise therapy and weight loss (Roddy 2005) are examples from the base of the pyramid. In more severe cases the recommendations are, for example, physiotherapy, NSAIDs and other pharmacological agents. In the most severe cases the option is surgery. Pharmacological treatment of OA remains controversial (Hunter 2006, Kalso 2004). The long‐term use of NSAIDs remains widespread despite increasing evidence for substantial toxicity associated with these agents (Caldwell 2006). It is therefore worthwhile to look into the evidence for less invasive therapy.
The aim of physical therapy treatment of osteoarthritis patients is to reduce pain and improve function in daily living. This could be achieved by increased muscle strength, improved balance and coordination of movements, and better joint mobility (Hurley 2003).
1. Improved muscle strength in osteoarthritis patients is correlated to the patient's functional level (Gur 2002). However, due to pain or very low functional level, it is often difficult to apply an adequate resistance training program.
2. Some modalities of electrotherapy like transcutaneous electrical nerve stimulation (TNS) and low level laser therapy are sometimes used (Osiri 2000; Hulme 2002; Bjordal 2003).
3. Traction and mobilisation have been mentioned as possible physical interventions. The biological rationale for these interventions is far from clear. They require empirical assessment of their effectiveness.
Traction is a passive treatment, meaning that the patient is relaxing while the therapist performs a passive joint motion to evaluate and treat the joint. The purpose of the joint movement is to separate the articular surfaces in the joint in a perpendicular direction to the joint surfaces. The aim is to reduce pain and improve functional status according to impairment and activity dimensions. Impairment and activity are terms used accordingly to the International Classification of Functioning, Disability and Health (ICF) (WHO 2001). Kaltenborn (Kaltenborn 2002) describes the force of traction as grade I to III and recommends grade I or II manual traction as the safest pain‐relief mobilisation and grade III joint mobilisation to restore normal joint gliding. Manipulation (trust technique) is a high velocity, low amplitude movement which the patient cannot prevent from taking place (Kaltenborn 2002; Maitland 2001). It might be used both for pain reduction, muscle relaxation and normalisation of joint gliding together with traction. In Kendall (Kendall 1993:337) traction is described as a force used therapeutically for the purpose of elongating or stretch of joint structures and/or muscles. Properly applied, the force pulls in the direction of separation or distraction of extremity joints or vertebral bodies. Traction may be applied manually, or a mechanical traction device, static weights or positional traction may be used. According to the Royal Dutch Society for Physical Therapy guidelines for physical therapy in patients with osteoarthritis of the hip or knee (Vogels 2003), traction and joint manipulation are recommended for pain relief and impairments related to movement. To our knowledge there has not been published any documentation on adverse events following traction of the hip.
Objectives
To compare the effectiveness and harms of traction interventions in patients with hip osteoarthritis to other interventions or no intervention on pain, activities of daily living, range of motion and quality of life.
Methods
Criteria for considering studies for this review
Types of studies
Randomised controlled trials will be considered for inclusion.
Types of participants
Patients of any age with osteoarthritis (OA) in either one or both hips. All degrees of OA will be eligible, both primary and secondary. All patients with OA will be grouped together irrespective of gender, age and the aetiology of the OA. Studies involving patients who suffer from any other arthritic conditions or any other diseases which may affect the hip will be excluded.
Types of interventions
Studies using the following interventions will be considered for inclusion.
1. Traction either manual or mechanical.
2. Traction combined with other forms of mobilisation.
3. Traction combined with manipulation.
4. Traction combined with other forms of interventions (for example, therapeutic exercise, modalities of electrotherapy).
The following comparisons will be included.
1. Traction versus no intervention.
2. Traction versus other intervention.
3. Traction combined with other intervention versus no treatment.
4. Traction versus traction with different force or direction of traction.
All types of traction force and directions of traction will be permitted. When the studies compare different traction programs, force, traction direction and duration must have been described.
Types of outcome measures
The primary outcome for measurement of effectiveness will be the benefit or harm of traction therapy. Beneficial outcome measures recommended by OMERACT III (Bellamy 1997) will include the following outcomes.
Primary outcomes
1. Pain
2. Functional status, for example measured by:
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Activity of daily living scales
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Quality of life measurements
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Patient global assessment
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Knee and hip osteoarthritis index (WOMAC)
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Harris hip score
Secondary outcomes
1. Consumption of non‐steroidal anti‐inflammatory drugs (NSAIDs)
2. Consumption of other analgesics and corticosteroids
3. Range of motion
4. Use of home care (home care is health care provided in the patient's home by health care professionals)
5. Time to surgery
6. Return to work
7. Psychological well‐being (for example, coping skills)
8. Walking speed and use of gait aids
9. Radiographic findings
10. Adverse effects
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Number of withdrawals due to adverse events (for example, increased pain, subluxation)
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Total adverse events
Search methods for identification of studies
The search strategy will be devised to find papers about traction for osteoarthritis of the hip joint. We will start searching where we expect the highest yield. The following databases will be searched, with no language restrictions.
1. Cochrane Central Register of Controlled Trials (via Wiley, latest issue available).
2. Ovid MEDLINE (1966‐ )
3. Ovid EMBASE (1980‐)
4. Ovid CINAHL ‐ Cumulative Index to Nursing and Allied Health Literature (1982‐)
5. Ovid AMED ‐ Allied and Complementary Medicine (1985‐)
6. ISI Web of Science (1975‐)
7. PEDro ‐ Physiotherapy Evidence Database (PEDro) (1929‐)
9. Cochrane Musculoskeletal Group registry.
We will use the following strategy to search the MEDLINE database: Appendix 1.
The strategy will be modified to the other databases listed above. If necessary the strategy will be revised. The Cochrane highly sensitive search strategy for MEDLINE (Higgins 2006) will be used to restrict the search to randomised controlled trials.
Unpublished and ongoing trials will be identified by correspondence with authors and field experts. Grey literature will be sought by contacting experts and by searching the following databases:
1. Science and Technology Proceedings via ISI Web of Science (1990 ‐)
2. Index of Conference Proceedings via British Library (1964 ‐)
3. Conference Papers Index via STN (1973 ‐)
4. Dissertation Abstracts via Proquest (1975 ‐)
In addition, reference lists of relevant studies and reviews will be examined. The reference lists of all retrieved studies will be scanned for additional studies and citation searches will be performed in ISI Web of Science.
Data collection and analysis
Selection of trials
All titles and abstracts will be independently screened by two review authors (AW and HL or RA and MH). Any discrepancies will be resolved within each pair or by consulting a third review author (GJ). Contact will be made with the authors when necessary. Blinding will not be used in assessment of inclusion criteria.
Assessment of methodological quality of included studies
Quality of studies will be assessed according to established criteria (Maxwell 2006). The assessment will be carried out by two independent review authors (AW and HL or RA and MH). Any discrepancies will be resolved within each pair or by consulting a third review author (GJ). Studies will be assigned to quality categories as described in The Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2006). Any discrepancies will be resolved by discussion.
The following criteria will be used:
1. concealment of allocation;
2. outcome assessment;
3. co‐interventions;
4. losses to follow up;
5. intention to treat.
Concealment of allocation
A. Adequate concealment: allocation of participants to different groups was not known until the point of allocation (for example, sequentially numbered, sealed, opaque envelopes, onsite computer system with locked unreadable files).
B. Unclear concealment (for example, stating only that a list or table was used).
C. Inadequate concealment: transparent before allocation (for example, alternation, case record numbers, dates of birth or days of the week).
D. Not used: clear that allocation concealment was not used.
Outcome assessment
Met: Assessor unaware of the assigned treatment when collecting outcome measures.
Unclear: Blinding of assessor not reported and cannot be verified by contacting investigators.
Not met: Assessor aware of the assigned treatment when collecting outcome measures.
Co‐interventions
Met: Interventions other than traction avoided, controlled or used similarly across comparison groups.
Unclear: Use of interventions other than traction not reported and cannot be verified by contacting the investigators.
Not met: Dissimilar use of interventions other than traction across comparison groups, i.e. differences in the care provided to the participants in the comparison groups other than the intervention under investigation.
Losses to follow up:
Met: Losses to follow up less than 20% and equally distributed between comparison groups.
Unclear: Losses to follow up not reported.
Not met: Losses to follow up greater than 20%.
Intention to treat.
Met: Intention to treat analyses performed or possible with data provided.
Unclear: Intention to treat not reported, and cannot be verified by contacting the investigators.
Not met: Intention to treat analyses not done and not possible for review authors to calculate independently.
Individual quality criteria will be summarised for each included study. The following categories will be used: low, moderate or high risk of bias. The overall assessment corresponds to all criteria met, one or more criteria unclear and one or more criteria not met (Maxwell 2006).
Data extraction and management
Data will be extracted independently by four review authors (AW, RA, HL, GJ) and compared using data extraction sheets and the "double entry" feature in RevMan 4.2 (RevMan 2005). Data concerning population, age, the control group, baseline characteristics, intervention characteristics and duration, compliance, and outcome measures will be extracted. Where it is not possible to extract data because they are not available or further information was needed, the first author of the paper will be contacted for clarification. The data will be presented in the 'Characteristics of included studies' table.
Measures of treatment effect
Overall effects from the studies which data are available will be calculated. For dichotomous outcomes included adverse events, we will calculate relative risk (RR), or alternatively Peto odds ratio (OR) if rare events. For continuous outcomes and similar outcome measures, weighted mean differences (WMD) and 95% confidence intervals will be calculated using a fixed effects model. If continuous outcomes are measured with similar, but not identical, instruments across studies, standardised mean differences will be calculated.
Assessment of heterogeneity
Heterogeneity will be tested using the Chi‐squared test of heterogeneity along with visual inspection of the graph. If the p‐value of this test is lower than 0.10, an I‐squared test (Higgins 2006:137) will be performed. If the I‐squared test shows a value greater than 50%, we consider this to indicate substantial heterogeneity, and a random effects model will be used for meta‐analysis.
Assessment of reporting biases
Funnel plots will be drawn to investigate any relationship between effect size and study precision (closely related to sample size). Such a relationship could be due to publication or related biases or due to systematic differences between small and large studies. If a relationship is identified clinical diversity of the studies will be further examined as a possible explanation (Egger 2001).
Data synthesis (meta‐analysis)
For both the dichotomous and the continuous outcomes a fixed effects model will be used for calculation of treatment effects and harms unless there is statistical heterogeneity. In cases of statistical heterogeneity, treatment effects will be calculated in a random effects‐model. Where studies contained more than one eligible intervention versus a control group, the data from the similar interventions will be pooled for use in the analysis. If data are too heterogeneous with respect to interventions, participants or outcome measures, a descriptive analysis will be done. The same will be done for studies not providing sufficient data to calculate overall effects.
Subgroup analyses
Analyses will be carried out for the whole group or subgroups of different interventions, by gender, by differences in the length/period of the intervention, and by intensity of the intervention.
Sensitivity analyses
Primary analyses will be based on available data from all included studies relevant to the comparison and outcome of interest. In order to assess the robustness of conclusions to quality of data and clinical heterogeneity, sensitivity analyses will be performed in terms of studies of different levels of methodological quality. If feasible, sensitivity analyses based on trials which require a strict diagnosis versus those that do not will also be performed.
Grading of evidence
We will use the grading system described in the 2004 book Evidence‐based Rheumatology (Tugwell 2004) and recommended by the Cochrane Musculoskeletal Group:
Platinum: A published systematic review that has at least two individual controlled trials each satisfying the following:
·Sample sizes of at least 50 per group ‐ if these do not find a statistically significant difference, they are adequately powered for a 20% relative difference in the relevant outcome.
·Blinding of patients and assessors for outcomes.
·Handling of withdrawals > 80% follow up (imputations based on methods such as last observation carried forward (LOCF) are acceptable).
·Concealment of treatment allocation.
Gold: At least one randomised clinical trial meeting all of the following criteria for the major outcome(s) as reported:
·Sample sizes of at least 50 per group ‐ if these do not find a statistically significant difference, they are adequately powered for a 20% relative difference in the relevant outcome.
·Blinding of patients and assessors for outcomes.
·Handling of withdrawals > 80% follow up (imputations based on methods such as LOCF are acceptable).
·Concealment of treatment allocation.
Silver: A systematic review or randomised trial that does not meet the above criteria. Silver ranking would also include evidence from at least one study of non‐randomised cohorts that did and did not receive the therapy, or evidence from at least one high quality case‐control study. A randomised trial with a 'head‐to‐head' comparison of agents would be considered silver level ranking unless a reference were provided to a comparison of one of the agents to placebo showing at least a 20% relative difference.
Bronze: The bronze ranking is given to evidence from at least one high quality case series without controls (including simple before/after studies in which patients act as their own control) or if the conclusion is derived from expert opinion based on clinical experience without reference to any of the foregoing (for example, argument from physiology, bench research or first principles).
Clinical relevance tables
Clinical relevance tables will be compiled under Additional Tables for the primary outcomes and the main adverse effect to improve the readability of the review. For dichotomous outcomes, the weighted absolute risk difference will be calculated using the risk difference (RD) statistic in RevMan. RD ‐ 1 calculates the weighted relative per cent change. The number needed to treat (NNT) will be calculated from the control group event rate (unless the population event rate is known) and the risk difference using the Visual Rx NNT calculator (Cates 2004).
Continuous outcome tables will also be presented under additional tables. Weighted absolute change will be calculated from the weighted mean difference (WMD) statistic in RevMan when trials using the same scale are pooled. For outcomes pooled on different scales, the standardised mean difference (SMD) is multiplied by the baseline standard deviation in the control group to obtain the weighted absolute change. Relative per cent change from baseline will be calculated as the absolute benefit divided by the baseline mean of the control group. NNT is calculated using the Wells calculator software available from the Cochrane Musculoskeletal Group. The minimal clinically important difference (MCID) for each outcome will be determined for input into the calculator.
