Abstract
Background
Joint motion is an essential component of hand function, but wounds limit movement, resulting in decreased hand function. Early movement is required to prevent tissue adhesions forming. Mechanotherapy is the specific use of therapeutic exercise to promote the repair and remodelling of injured tissue; however, pain experienced during movement can be a barrier to achieving full motion. The overarching aim of this thesis was to gain an understanding of silicone oil as an adjunct to modulate the level of pain experienced by patients with hand wounds as they perform prescribed hand exercises.
Aims To explore the use of silicone wound care products through a hand therapy lens.
To investigate the feasibility of conducting a randomised clinical trial of the effectiveness of silicone oil for modulating the intensity level of pain experienced by patients performing hand exercises during wound healing.
Methods
To address these aims, four sequential and complementary research projects were completed. First, I performed a narrative review of the literature to create a body of knowledge relevant to hand therapists. Literature pertaining to the human integumentary system, wound healing, and the rationale for the various types of medical silicone was collated and discussed.
Second, I completed a scoping review It described how, and for what reasons, silicone products are used internationally as a wound care layer. The review identified the most frequently used outcome measures in wound care studies investigating silicone and the most common wound types and locations in the upper limb.
Third, the use of silicone oil in clinical practice was investigated via a survey of Australasian hand therapists. The questionnaire quantified silicone oil use by hand therapists and explored their perceptions of silicone oil, its value in clinical practice, and reasons for use.
Lastly, the efficacy of silicone oil was explored via a feasibility study. In preparation for a randomised controlled trial (RCT), the treatment fidelity when implementing an exercise programme using silicone as a wound care intervention was examined. The numerical pain rating scale was used as the primary outcome measure. The study group chosen for the RCT had undergone a surgical release of flexion contracture in the hand caused by Dupuytren’s disease. A key objective for the RCT feasibility study was to define an appropriate exercise dosage protocol for use with silicone oil.
Results
The narrative and scoping reviews demonstrate the use of silicone, in different physical forms, as a dressing for wounds healing by secondary intent. Included research suggested that silicone use reduces the level of pain experienced during dressing changes. In addition, the atraumatic properties of silicone promoted epithelisation resulting in speedy wound closure.
Surveyed hand therapists’ use of silicone oil in clinical practice was 43%. The survey found that silicone oil appeared to lessen movement-evoked pain in hands with wounds healing by secondary intention. However, knowledge surrounding silicone oil use was limited, and a need for easy access to recent evidence to support clinical use of this adjunct was realised. Therapists reported the key indicator for silicone oil use in clinical practice was for rehabilitation following Dupuytren’s contracture release surgery.
High treatment fidelity was achieved when hand therapists delivered a specific protocol of hand exercises, with participants randomised to either usual care or in silicone oil following Dupuytren’s surgery. Comparison of the numerical pain rating scale scores between the two groups was performed to ascertain if pain intensity levels differed for those who exercised their wounded hands in silicone oil. No statistically significant difference was identified within the small study sample. The feasibility for conducting a fully powered trial using this study methodology was found to be low. Changes in both recruitment methods and inclusion criteria are required to ensure that appropriate sample sizes can be achieved.
Conclusion
By developing an understanding of the range of silicone products used in wound healing, why they are used, and confirmation of hand therapists’ use of silicone oil in clinical practice, a solid foundation of research was formed. This foundation formed my development of an RCT protocol. Future research of silicon oil’s efficacy for pain modulation experienced during hand exercises can use the intervention model developed in this thesis. High treatment fidelity demonstrates that the silicone oil intervention and exercise protocol was acceptable to participants, easy for hand therapists to teach, and achievable for the Dupuytren’s population to implement at home. Inclusion of outcome measures that address scar quality and infection rates would strengthen the study design. Silicone oil as a topical application in wound care had no adverse events associated with its use in the literature review, survey of hand therapists, or the feasibility study, confirming its safety for use in hand therapy.