Case Study | Positioning Control and Rehab Support for a Non-Ambulatory Patient

H.K. is a 16-year-old female who has been diagnosed with hydrocephalus and muscle contractures. She is currently non-ambulatory and has worn DAFO 4 supra-malleolar orthoses in the past. She was recently scheduled to see us because she had outgrown her braces and needed to be evaluated for a new pair. H.K.’s physical therapist reported at the visit that her primary goal for the braces is to provide positioning control. As H.K. has successfully healed from hip surgery, the PT would like to begin rehabilitation. This program is expected to include supported standing.

Initial observation revealed narrow feet with delicate-looking skin and coloring that hinted at possible circulation problems (Fig.1). Her heels were significantly out of alignment in a valgus position, the forefoot was abducted, the lateral border was raised, and she had flat medial longitudinal arches. The navicular, 1st metatarsal phalangeal (MP) joint and base of 5th metatarsal were very prominent points of surface anatomy. The uncorrected position of her feet appeared to be approaching a raised heel, rocker-bottom shape. Her feet were severely pronated and ankle alignment was plantarflexed. The parent’s concerns about skin breakdown verified the need to approach brace selection with extra special attention to comfort and skin health.

A team consisting of the PT, orthotist, orthotic assistant and patient’s mother discussed the merits and drawbacks of several styles and settled on the DAFO 3.5 Softy design. The separate inner liner will protect the skin as the foot is slipped into the slightly open trimlines of the plastic outer shell. This also makes donning a bit easier by creating a two-stage routine of foot position followed by dorsiflexion (DF) correction. The posterior strut of the 3.5 will allow enough support without going beyond what is required for occasional supported standing. The posterior upright, proximal cuff and anterior strap will work together with the full wrap-around foot section of the brace to control foot and ankle position to a higher degree than a lower brace style could provide. The tibial section is more open than a fully wrapped AFO and will provide more air flow to her delicate skin. The team was pleased with their decision and ready to move on to the next step.

Upon manipulation, I discovered a range of motion that would allow significant, though not complete, correction to H.K.’s foot and ankle position. A helper was enlisted to hold her knee in a fixed position in the frontal plane. With a firm grip covering a maximum surface area, each foot was gently moved closer to a balanced alignment. One hand wrapped around her heel and the other at her forefoot allowed the proximal and distal sections of the foot to aid each other in correction. Moving the forefoot into a more varus position made correcting the heel easier; with a stable heel, the forefoot could be moved slowly down to neutral. With the foot alignment held, I gradually moved her ankle alignment toward DF (Fig.2). I knew that if I could not keep her heel firmly corrected in my hand as we moved beyond what she could tolerate in DF correction, the brace would not be able to hold her heel, either. Surprisingly, H.K.’s foot was able to correct to only a few degrees away from a vertical heel, a neutral forefoot and a 90-degree dorsiflexion angle. Her navicular tucked in dramatically when her foot and ankle position were corrected, though it will remain a point of concern.

Now that we had rehearsed the goal for a finished brace position, I was ready to cast. Because H.K.’s feet have been subject to high muscle tone and very little weight bearing, they are unique in shape as compared to the majority of patients we see. After checking her fit with the Cascade PollyEthel Casting Footplates, I decided they would hide rather than enhance her foot shape. This was one of those rare times when I elected to cast without them.

After applying the standard two layers of 2-inch stockinette with a buffer strip between them, I was ready to wrap with fiberglass. I applied the tape with a fairly tight overlapping wrap to be sure every nuance of H.K.’s foot was captured for the technicians at Cascade. A 90-degree flexion at the knee with downward pressure applied by the helper gave me enough of a weight bearing simulation to measure accurately. I then repeated the previously rehearsed manipulation toward her best possible position of function (Fig. 3). I held the position with intermittent hand repositioning. As the tape cured to a more plastic stage, I made sure to further define around the Achilles tendon, heel, malleoli and toes, also pushing in at the metatarsal arch, peroneal arch and sustentaculum tali (ST) groove. This was also when I emphasized the navicular, 1st MP and base of 5th metatarsal by pressing in directly around each prominence. Soon the cast had dried to a hard shell and was ready to carve off along the buffer strip with a hook blade knife. I removed the cast and checked it for accuracy.

After casting both feet, the helper filled out the 3.5 Softy work order form, asking for no angle correction from the cast to the finished brace. We made a special request of plastizote padding at the navicular, base of 5th and 1st MP joint to allow focused relief into this compressible material. To allow for ease of shoe fit, we also asked for no bottom treatment.

At the fitting appointment, I fine-tuned the toe length and distal medial and lateral trimlines by removing any unnecessary length. I shared the break-in schedule and warranty information with the family and caregiver, including a reminder to be on guard for any problems with skin irritation or trouble with habituation. They are an experienced family and know to report any concerns to the PT or orthotist’s office right away should they occur.

Though we will keep it in mind, this adjustment was not necessary at the fitting (Fig. 5). In fact, if all goes as well as planned, we won’t have the pleasure of seeing H.K. again for quite some time.

—Loretta Sheldon, ROA

Loretta Sheldon is an ABC Registered Orthotic Assistant and a member of Cascade’s management team. She has been with Cascade since 1998.

Fig. 1. H.K.’s feet on initial observation. Fig. 2. Holding H.K.’s foot in our goal for a finished brace position: only a few degrees away from a vertical heel, neutral forefoot and 90-degree dorsiflexion ankle.
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Easy Navicular Relief

If the navicular area does crop up later as a problem, the 3.5 Softy design allows for a particularly good solution. A hole can be cut in the plastic just slightly beyond the apex of the navicular (Fig. 4). This will allow the navicular to ease out through the plastic while it continues to remain contained by the soft liner.

Fig. 4
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Fig. 5. H.K. wearing the braces, feet gently corrected.