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Walkers good alternative for post-op stability treatment
We thought you’d be interested to hear about a study that was published in April’s issue of Foot & Ankle International which compared post-operative sagittal plane stability treatment options between a traditional fibreglass cast and a range of pneumatic walkers.
Understanding the importance of the stability of postoperative immobilisation following foot and ankle surgery and observing an increase in the use of braces, researchers from the Dept. of Orthopedic Surgery at the University of Michigan set out to evaluate the sagittal plane range of motion allowed in different types of walkers in comparison to a fibreglass cast.
Ten healthy subjects (5 male and 5 female) participated in the study which tested four off-the-shelf braces (Aircast’s XP Walker, FP Walker and SP Walker and DonJoy’s Max Trax Walker) against a fibreglass cast. All casts were allowed 30 minutes to harden while the air cells in the walkers were inflated to a comfortable fitting. Each volunteer had a custom shaped radio-opaque metal plate placed on the plantar aspect of their feet to serve as a radiographic marker to assess tibiopedal motion. Maximum dorsiflexion and maximum plantarflexion lateral radiographs were taken without any immobilisation, in the fibreglass cast and all walkers. In order to allow for consistent measurement, total tibiopedal motion was measured. The total range of motion in each type of immobilization was measured by combining the maximal dorsiflexion and maximal plantarflexion ranges of motion.
The researchers found that when the fibreglass cast had initially hardened, it limited 88% of the subject’s sagittal plane motion, allowing a mean of 8.4 degrees of motion (S.D. 4.3 degrees), which compared well to the top two walkers - Aircast XP Pneumatic Walker, 15.4 degrees (SD, 5.6 degrees) and Aircast FP Foam Walker, 16 degrees (SD, 6.7 degrees).
However, the researchers only measured the volunteers’ sagittal plane motion when the cast was first applied. This didn’t take into account that the rigidity and conformity of the cast is only at its most restrictive when it is first fitted and that it will deteriorate over time as the padding compresses, the patient’s oedema reduces and the calf muscle atrophies. Cast conformity is also in jeopardy if the patient’s ankle moves even slightly during cast application.
The researchers found that although the braces initially allowed more ROM than the cast, they had several advantages: for example, they allow regular wound access and skin care, plus the added benefit of allowing for the changes in swelling by adjusting the air cells or straps. As a result, they suggested that should a patient have significant post operative oedema, they would benefit from a brace rather than a cast for superior long-term control of the sagittal tibiopedal range of motion.
Radiographic Comparison of Sagittal Plane Stability Between Cast and Boots - Anish R. Kadakia, M.D.; Norman Espinosa, M.D.; Jonathan Smerek, M.D.; Kacey White
Foot & Ankle International, Vol. 29, No. 4, pp. 421-426 April 2008
