Hip knee ankle foot ort h osis(HKAFO) & Hip Orth o sis DR. EHTISHAM UL HAQ
Indic a tions Assist gait Decrease weight bearing Control Movement Minimize progression of a deformity
Principle of Equilibrium This system applies corrective and assertive forces which are implemented at surface of orthosis through skin and transmitted to underlying soft tissue and bones To remain stable ,the body has to have one point of pressure opposed by two equal points of counter pressure Hip joint: F3 =F2+F4 Knee joint: F2=F1+F3 Forces F1, F2, and F3 control knee flexion, while forces F2, F3, and F4 control hip flexion
Co nt. The corrective force is directed towards the angular or deformed area to be corrected and other two counter forces are applied distal and proximal to the corrective forces The greater the distance between the force and the counter force ,the less counter force required
Hip knee ankle foot orthosis A hip–knee–ankle–foot orthosis (HKAFO) is an orthosis whose components stabilize or lock the hip, knee and ankle The typical HKAFO is a pair of KAFOs linked above the hip with either a pelvic band, lumbosacral orthosis The hip section provides significant stability in the transverse plane and, if the hip joints are locked, also provides sagittal plane stability
Co m po nents: HKAFO is extension of KAFO which contains AFO knee joint two upright calf band quadrilateral thigh section. Hip joint Pelvic band
AFO component: It may be metallic AFO or plastic AFO. Metalic AFO components are 1)proximal calf band two medial and lateral bar ankle joint two stir up.
Fabrication process of plastic AFO Step 1: Creating a negative plaster mould of patient's lower leg and foot Step 2: Cutting and removing plaster mold from patient Step 3: Pouring liquid plaster into the negative plaster mold Step 4: Modifing the positive plaster cast
Step 5: Moulding the HDPE plastic Step 6: Removing & Cutting the plastic from positive cast Step 7: Finishing the plastic shape Step 8: Fitting the patient
Two upright (medial and lateral) attached to the drop lock knee joint from above and below and connects AFO & lower thigh band respectively. Straight set knee joint allows free flexion and prevents hyperextension. It is used with drop lock which is a wedge shaped metal piece that is placed on upright bar. When knee extends it drops over the joint and locks it Width at knee joint = Anatomical knee width + 10 to 12 mm
Quadrilateral thigh sections The quadrilateral thigh section is designed to permit partial transfer of the patient’s weight through the KAFO during stance phase which is made of HDPE plastic . This brings more effective balance to the patient’s gait as the resultant stance period.
Hip joint Hip joint is attached to KAFO which allows flexion extension only. Movement of hip with a uniaxial hip joint with drop lock which is locked during walking Distance between knee axis to greater trochanter is measured. Hip joint is placed on the lateral side of brace till the axis of hip joint is at the measured distance from knee joint axis to greater trochanter Hip joint bar attached to knee joint bar with nails HIP JOINT AXIS KNEE JO I NT AXIS
Pelvic band A pelvic band which is padded rigid steel band extending posteriorly and laterally which fits between iliac crest and greater trochanter In front it is fastened with a soft Velcro or buckle strap fastener .on the lateral side it is attached to hip joint Measurement of pelvic band: length of pelvic band =(circumference at pelvic level –ASIS to ASIS distance) + 50 mm Cutting off excess length of pelvic band if required equally from both side & banding is done
Indic a tion: Bilateral HKAFOs designed for standing and ambulation in adults with paraplegia. It provides the paraplegic patient who has a complete neurological level at L1 or lower with a more functional and comfortable gait
Reciprocal Gait Orthosis (RGO) A reciprocating gait orthosis (RGO) is an HKAFO that uses a mechanical system that connects the two sides of the brace by Isocentric bar (IRGO) Double cable (LSU RGO from Louisiana State University) Single push/pull cable system (advanced RGO [ARGO] )
Components : AFO Knee joint Uprights Thigh cuff Hip joint Pelvic band Cables (In the isocentric RGO (IRGO) , the cord is substituted by a pelvic band attached to the posterior surface of the molded thoracic section) Thoracic straps
In all RGOs, the hip joints are coupled together with cables(pelvic band in the IRGO) which provides mechanical assistance to hip extension while preventing simultaneous bilateral hip flexion As a step is initiated and hip flexion takes place on one side, the cable coupling induces hip extension on the opposite side, producing a reciprocal walking pattern Forward stepping is achieved by active hip flexion, lower abdominal muscle Using 2 crutches and an RGO, paraplegics can ambulate with a 4-point gait. A walker may also be used
Hip Orthoses Hip orthoses (HpOs) may be prescribed for isolated problems in the acetabular region, which may be the result of (1)Dysplastic disorders (2) traumatic injury (3) surgical procedures (total hip replacement)
Orthosis in dislocation of hip joint Once reduced, a total hip can be stabilized with an orthosis until the compromised soft tissue heals and creates scarring around the joint This usually prevents further dislocations if the femoral and acetabular components are well positioned In the past, hip spica casts have been shown to be useful for this purpose. Currently, orthoses offer several advantages over casts. Orthoses weigh less, which makes them easier totolerate during ambulation
Posterior dislocations Violence directed along shaft of femur with hip flexed is the mechanism of injury The hip orthosis used to treat a hip that dislocates in a posterior direction is generally proximal to the knee A pelvic band suspends the orthosis and provides an attachment point for the hip joint A laterally placed, adjustable range of motion hip joint capable of controlling flexion, extension, abduction, and adduction which attaches to a thigh cuff that holds the hip in 10 to 20 degrees of abduction and allows 0 to 70 degrees of flexion
Anterior dislocation When patients have anterior wall weakness or global instability external rotation and abduction usually is the mechanism of dislocation To provide rotational control, a knee–ankle–foot orthosis (KAFO) rather than a simple thigh cuff is suspended from the pelvic band
Pediatric hip orthosis Conditions that fall within this category include Developmental dysplasia of the hip (DDH) Legg-Calve´-Perthes disease (LCP) cerebral palsy (CP) lower limb weakness or paralysis associated with neuromuscular disorders, myelodysplasia, and spinal cord injury
Dev e lo p mental dy s p la s ia of the hip (DDH) Ortho s is Frejka pillow : In 1941, Bedrich Frejka introduced a soft abduction pillow for treatment of DDH in infants The Frejka pillow was designed to maintain abduction . the pillow is soft nature, infants could easily overcome the abduction pressure. The pillow subsequently was modified to create a firmer construct The most recent version consists of a 9- 9- ¾ inch foam pillow that is placed around the child’s buttocks, much like a diaper, and secured in place with a cloth harness and straps
Pavlik harness The Pavlik harness has two shoulder straps that cross in the back and are secured to a wide chest strap The anterior stirrup straps are located at the anterior axillary line and the posterior straps overlie the scapulae The anterior straps should maintain the hips in 90 to 110 degrees of flexion. posterior straps are designed to maintain wide abduction The straps should be tension to maintain 20 to 30 degrees of abduction only
Plastazote hip abduction orthosis Braces are made of a Plastazote foam that wraps around the legs and waist, maintaining the hips in approximately 70 to 90 degrees of flexion and wide abduction . Both allow free motion of the knee Hedequist et al.reported the successful use of an abduction brace in 13 of 15 patients with dislocated hips who had not responded to Pavlik treatment
Orthosis of cerebral pulsy Resting abduction orthosis: Night time abduction splinting theoretically is an attractive option for treating young children with early subluxation due to spastic quadriplegia or diplegia By maintaining stretch on the hip adductors and flexors , these devices should enable patients to maintain, or even improve, range of motion By positioning the hip in the central position within the acetabulum, the devices ideally should promote normal acetabular growth One of the simplest forms of resting splints is a foam wedge, which can be held in place by hook-and-loop straps
The SWASH (standing, walking, and sitting hip) orthosis It is designed to allow the wearer to transition from sitting or crawling to standing or walking By providing variable hip abduction according to the degree of flexion or extension, it maintains the hips in abduction while the child is seated and holds the legs almost parallel while the child is standing The brace not only positions the hips in abduction, providing maximal coverage to the femoral head, but also helps with sitting balance and preventing scissoring with ambulation
Standing frame orthoses The standing brace allow independent standing and free use of the upper extremities for the very young child with good head control .It does not permit hip or knee flexion The brace comes as a kit that consists of an unhinged upright frame with footplates, knee supports, and a chest/abdominal strap. It can be extended to accommodate growth
Para p od i um It enables the child to sit or stand as well to change between these two positions. The original design included only hip locks; however, subsequent models include locking and unlocking joints at both the knee and hips, which allow the child to sit in a wheelchair as well as to stand The parapodium is indicated for children older than 3 years. It is worn over clothing. It provides an exoskeleton that consists of a spring-loaded shoe clamp, aluminum uprights, foam knee block, and back and chest panels
Refe r enc es: Atlas of orthosis by AAOS Physical medicine and rehabilitation by Braddom Physical medicine and rehabilitation by Board review