What is the aim of this review?
The aim of this review was to determine whether rigid dressings are more effective than soft dressings in helping the wound to heal following transtibial (below the knee) amputations. Researchers from Cochrane searched for all relevant studies (randomised controlled trials (RCTs) and quasi-randomised controlled trials) to answer this question and found nine relevant studies.
Key messages
The certainty of evidence for all outcomes was very low because the results could not rule in or rule out important benefits or harms, and because the design and reporting of the studies was not of a high standard. Therefore, we cannot be certain if the use of rigid dressings leads to better or worse patient outcomes compared with soft dressings.
What was studied in the review?
We studied the effects of rigid dressings such as plaster casts or fibreglass dressings on outcomes including wound healing, adverse events, prescription of prosthetics, physical function, length of hospital stay, patient comfort, quality of life, cost and swelling in people following transtibial amputations. Rigid dressings were compared with soft dressings such as gauze or elastic bandages in all included studies.
What are the main results of the review?
We included results from nine RCTs and quasi-RCTs involving 436 participants (441 limbs) in this review. Participants were recruited from acute and/or rehabilitation hospitals from seven different countries. Sample sizes of studies ranged from 15 to 154, while the average age of participants ranged from 54 to 75. More than half of all participants had diabetes and other co-morbidities (e.g. anaemia, smoking history, hypertension, cardiac disease). Amputations were all secondary to vascular conditions (e.g. peripheral artery disease) although the cause of amputation was not always specified.
We are uncertain whether rigid dressings lead to more wounds healed, fewer adverse events, faster recovery time for pain and wound healing, walking and prosthetic prescription, greater reduction in swelling, and a shorter hospital stay, compared with soft dressings. We are unsure about these results because all studies had very severe methodological limitations, and most results were based on a small number of studies (i.e. one to three studies of 21 to 65 participants).
How up to date is this review?
We searched for studies that had been published up to December 2018.
We are uncertain of the benefits and harms of rigid dressings compared with soft dressings for people undergoing transtibial amputation due to limited and very low-certainty evidence. It is not clear if rigid dressings are superior to soft dressings for improving outcomes related to wound healing, adverse events, prosthetic prescription, walking function, length of hospital stay and swelling. Clinicians should exercise clinical judgement as to which type of dressing they use, and consider the pros and cons of each for patients (e.g. patients with high risk of falling may benefit from the protection offered by a rigid dressing, and patients with poor skin integrity may have less risk of skin breakdown from a soft dressing).
Dressings are part of the routine postoperative management of people after transtibial amputation. Two types of dressings are commonly used; soft dressings (e.g. elastic bandages, crepe bandages) and rigid dressings (e.g. non-removable rigid dressings, removable rigid dressings, immediate postoperative protheses). Soft dressings are the conventional dressing choice as they are cheap and easy to apply, while rigid dressings are costly, more time consuming to apply and require skilled personnel to apply the dressings. However, rigid dressings have been suggested to result in faster wound healing due to the hard exterior providing a greater degree of compression to the stump.
To assess the benefits and harms of rigid dressings versus soft dressings for treating transtibial amputations.
In December 2018 we searched the Cochrane Wounds Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE, Ovid Embase, EBSCO CINAHL Plus, Ovid AMED and PEDro to identify relevant trials. To identify further published, unpublished and ongoing studies, we also searched clinical trial registries, the grey literature, the reference lists of relevant studies and reviews identified in prior searches. We used the Cited Reference Search facility on ThomsonReuters Web of Science and contacted relevant individuals and organisations. There were no restrictions with respect to language, date of publication or study setting.
We included randomised controlled trials (RCTs) and quasi-RCTs that enrolled people with transtibial amputations. There were no restrictions on the age of participants and reasons for amputation. Trials that compared the effectiveness of rigid dressings with soft dressings were the main focus of this review.
Two review authors independently screened titles, abstracts and full-text publications for eligible studies. Two review authors also independently extracted data on study characteristics and outcomes, and performed risk of bias and GRADE assessments.
We included nine RCTs and quasi-RCTs involving 436 participants (441 limbs). All studies recruited participants from acute and/or rehabilitation hospitals from seven different countries (the USA, Australia, Indonesia, Thailand, Canada, France and the UK). In all but one study, it was clearly stated that amputations were secondary to vascular conditions.
Primary outcomes
Wound healing
We are uncertain whether rigid dressings decrease the time to wound healing compared with soft dressings (MD -25.60 days; 95% CI -49.08 to -2.12; one study, 56 participants); very low-certainty evidence, downgraded twice for very high risk of bias and once for serious imprecision. It is not clear whether rigid dressings increase the proportion of wounds healed compared with soft dressings (RR 1.14; 95% CI 0.74 to 1.76; one study, 51 participants); very low-certainty evidence, downgraded twice for very high risk of bias and twice for very serious imprecision.
Adverse events
It is not clear whether rigid dressings increase the proportion of skin-related adverse events compared with soft dressings (RR 0.65; 95% CI 0.32 to 1.32; I2 = 0%; six studies, 336 participants (340 limbs)); very low-certainty evidence, downgraded twice for very high risk of bias and once for serious imprecision.
It is not clear whether rigid dressings increase the proportion of non skin-related adverse events compared with soft dressings (RR 1.09; 95% CI 0.60 to 1.99; I2 = 0%; six studies, 342 participants (346 limbs)); very low-certainty evidence, downgraded twice for very high risk of bias and once for serious imprecision. In addition, we are uncertain whether rigid dressings decrease the time to no pain compared with soft dressings (MD -0.35 weeks; 95% CI -2.11 to 1.41; one study of 23 participants); very low-certainty evidence, downgraded twice for very high risk of bias and twice for very serious imprecision.
Secondary outcomes
We are uncertain whether rigid dressings decrease the time to walking compared with soft dressings (MD -3 days; 95% CI -9.96 to 3.96; one study, 56 participants); very low-certainty evidence, downgraded twice for very high risk of bias and twice for very serious imprecision. We are also uncertain whether rigid dressings decrease the length of hospital stay compared with soft dressings (MD -30.10 days; 95% CI -49.82 to -10.38; one study, 56 participants); very low-certainty evidence, downgraded twice for very high risk of bias and once for serious imprecision. It is also not clear whether rigid dressings decrease the time to readiness for prosthetic prescription and swelling compared with soft dressings, as results are based on very low-certainty evidence, downgraded twice for very high risk of bias and once/twice for serious/very serious imprecision. None of the studies reported outcomes on patient comfort, quality of life and cost.