Prosthetics and Orthotics





Prosthetics is the medical science surrounding the provision and use of artificial body parts (prostheses) as replacement, while orthotics is the medical science surrounding the provision and use of artificial devices such as braces (orthoses) to assist with limb malalignment or pathology. Prosthetists and orthotists are the health professionals who measure, design, fabricate, and fit prostheses (artificial body parts) and orthoses (braces).


Prosthetists specialize in functional and cosmetic restoration of all or part of a missing body part, as part of the patient’s inter-disciplinary team. Orthotists focus on orthoses designed to provide external control, correction, and support for the patient in need for nonoperative management of musculoskeletal and neuromuscular disorders, among others.


The words prosthetics and orthotics may be used as nouns to describe the body of knowledge each pertains to, as in the preceding two paragraphs. The devices are referred to as prostheses and orthoses. When referring to a specific device, the words prosthetic and orthotic are adjectives needing an appropriate noun.


Specialists in these areas are certified by the American Board for Certification and titled certified prosthetist (CP) and certified orthotist (CO). A certified prosthetist-orthotist (CPO) has demonstrated proficiency in both fields during examinations by the national board. Supportive personnel are orthotic and prosthetic assistants, orthotic fitters, and technicians, with varying responsibilities and duties.


Many major institutions have ongoing prosthetic and orthotic clinics or conferences that meet in accordance with patient needs. Members of the clinic team consist of a physician such as a physiatrist, physical and occupational therapists, a prosthetist, an orthotist, a nurse, and a social worker or case manager. The inter-disciplinary team approach is oriented toward management of the total patient, so although the rationale for prescription of an appropriate prosthetic or orthotic system is a prerequisite, the complete program is the long-range goal and responsibility of the team. Factors such as vocational retraining, if necessary, financial considerations of various phases of management, the necessity and duration of physical or occupational therapy, the clinical setting(s) where therapy is provided, and a possible need for psychologic counseling are all taken into account. Perhaps most important, the patient must feel comfortable in the clinical setting and be assured that the result will be as satisfactory as is realistic and attainable.


The prosthetist or orthotist is responsible for assisting with the prescription regarding components, elements of design, definitive and proper fitting of the system, and follow-up and adjustments as indicated at future visits to the clinic.


If prosthetic and orthotic practitioners are to serve patients at the highest professional level, they must continue their lifelong learning through post-professional development to remain informed of new techniques, components, and concepts. Such programs are available through the American Academy of Orthotists and Prosthetists. Other groups are the American Orthotics and Prosthetics Association (AOPA) and the Children’s Amputee Prosthetic Program (CAPP).


Prosthetics


Prosthetics, or artificial limbs, are designed to replace function and sometimes cosmesis of a missing body part. Internal prostheses are surgically implanted devices, such as the artificial hip, and are described in Chapter 8 .


Upper Limb Prosthetics


An upper limb prosthesis is an external system designed for the partial hand level amputation distally to the interscapulothoracic (forequarter) level proximally. This terminology is different from that that used by surgeons in describing the amputation levels.




  • elbow disarticulation (ED): amputation through the elbow joint. Correct with elbow disarticulation prosthesis with socket encompassing the residual limb and trimmed at the proximal humerus to allow good range of motion. This socket design is used with cable and figure-eight harness control, body-powered external elbow hinges with lock, wrist unit, and terminal device. The cable design can be either a Bowden single-control, fair-lead, or triple control cabling system.



  • interscapulothoracic (forequarter amputation): this level of amputation includes the resection of the scapula and clavicle. Correct with cosmetic shoulder cap to restore normal appearance for clothing, but differing in that an extension usually goes around and over the sound shoulder to provide additional suspension. The weight of the prosthesis assists in balance (postural symmetry) during sitting, standing, and walking on even and uneven surfaces. This system will be used with cable (Bowden, fair-lead, or triple) control, modified chest strap, and waist belt-type harnessing, excursion amplifier, shoulder joint similar to that used in shoulder disarticulations, internal locking elbow, forearm lift assist, wrist unit, and terminal device.



  • partial hand amputation: distal to or through one or more of the phalanges, metacarpals or resection at any level of the thumb. Restore function with cosmetic individual finger replacements with fillers and/or opposition posts. More proximal amputation sites necessitate cosmetic gloves and wired finger fillers or more intricately designed opposition posts to restore function. More active individuals, or individuals with careers that require more hand dexterity, with proximal partial hand amputations can benefit from body-powered or externally powered partial-hand prosthetic options.



  • shoulder disarticulation (SD): amputation through the glenohumeral joint. Correct with shoulder disarticulation prosthesis with larger socket extending from the spine posteriorly to near the xiphoid process anteriorly and fitted closely at the neck. May be used with a fair-lead cable, modified chest strap–type harness, shoulder joint or bulkhead (spacer) to allow passive positioning in abduction, adduction, flexion and extension, as well as active control of internal locking elbow, forearm lift assist, wrist unit, and terminal device.



  • transhumeral amputation (TH): previously referred to as an above elbow amputation ; proximal to elbow joint but distal to shoulder. The prosthetic socket will extend over the acromion to support axial loading and is carefully fitted at axilla. This design is used with a fair-lead cable and figure-eight harness, elbow unit, forearm lift assist, wrist unit, and terminal device. Depending on the length of the transhumeral amputation, the component will change. For example, a class I transhumeral amputation level will use outside locking hinges, whereas a class III amputation level will incorporate an internal locking elbow unit.



  • transradial amputation (TR): previously referred to as a below elbow amputation. Level of involvement is proximal to wrist but distal to elbow. TR prostheses are designed to fit the residual limb, retaining pronation and supination in the longer levels while allowing flexion. Several cable options are available based on length of residual limb, including a Bowden cable and fair-lead cable. Additional components include a figure-eight harness control, flexible or rigid elbow hinges, wrist unit, and terminal device. Münster-type prosthetic socket design makes the system applicable for short to very short transradial amputations. This socket design must be carefully fitted proximal to the epicondyles at the elbow to provide adequate suspension without the aid of additional devices.



  • wrist disarticulation (WD): amputation through the wrist joint. The prosthetic socket is designed to be donned over the bulbous (“screwdriver” shape) distal end of the residual limb, retaining as much pronation and supination as possible. The prosthetist will trim the anterior, medial, lateral, and posterior trim of the socket to allow functional motion. This socket design is used with a Bowden cable system, a figure-nine or figure-eight harness, flexible elbow hinges, wrist unit, and terminal device.



Upper Limb Prosthetic Components


The components of an upper limb prosthesis include any device that is a supportive or integral part of the prosthesis, including terminal devices.




  • control cables: steel cable traveling inside housing to move and lock mechanical joints, for example, flexion and locking of the elbow joint; also provide prehension to the terminal device. The housing is sometimes lined with Teflon to reduce friction and thereby increase efficiency. Cable systems are generally lightweight, as for small children, with standard ⅛-inch or heavy-duty cable (e.g., Bowden single, Fair-Lead dual, and triple control cables). Fig. 7-1 illustrates single control only.






    Fig. 7-1Control cable housing. (From Below and Above Harness and Control System, Evanston, IL, 1966, Northwestern University Prosthetic-Orthotic Center.)



  • elbow hinges: mechanical types of hinges to provide specific strength or allow controlled mobility. The following types are commonly used: single pivot providing mediolateral control, suspension polycentric, multiple action, sliding action step-up, and residual limb activated locking. These are all designed to provide additional forearm flexion for very short below-elbow amputations or the patient with flexion contracture.



  • electrical switch control: prosthesis for the patient with shoulder disarticulation or transhumeral or forequarter amputation; uses switches to control current from a battery that operates an electrical elbow or hand. The switches are placed in strategic positions within the harness system, and by opening these switches the patient is able to operate the electrical elbow or hand. This type of system is most feasible for patients with limited excursion from causes such as contractures, higher levels of amputation, or bilateral limbs, because each position in the switch is 1/16-inch excursion—considerably less than that required to operate the standard system.



  • excursion amplifier sleeve: pulley and cable system used to increase efficiency in patients with limited excursion; generally used in shoulder disarticulation and forequarter systems.



  • flexible hinges: hinges made of Dacron tape or metal spirals to provide suspension while allowing retention of available pronation and supination for long transradial and wrist disarticulation residual limb length. Supination and pronation are not available in very short, and some standard levels of amputation



  • forearm lift assist: adjustable spring-loaded device attached to the elbow to provide initial forearm flexion; especially applicable for those with higher level amputations such as shorter above-elbow amputation and shoulder disarticulation.



  • Griefer prosthesis: electrically enhanced, strong-gripping (terminal device) hand component.



  • myoelectric control: sophisticated prosthesis available for the patient with wrist disarticulation, below-elbow amputation, above-elbow amputation, or shoulder disarticulation: uses electrodes placed over the flexor and extensor muscle groups to pick up the milliamperes of electricity emitted by a muscle during contraction. This electrical stimulus is then used to operate a switch that controls a motor in a mechanical hand or other component. Prosthetic sockets are generally self-suspended, thereby eliminating the need for any harness.



  • nudge control: mechanical unit that can be pressed by the chin to lock or unlock one or more joints of the prosthesis; seen in forequarter systems.



  • outside locking hinge: used on the elbow disarticulation system because of length of residual limb. Outside locking elbow and internal positive locking elbow hinges with multiple locking positions are used for above-elbow, shoulder disarticulation, and forequarter systems.



  • shoulder harness, chest straps, and waist belts: a wide variety of Dacron, cloth, and leather materials is used to fabricate these components. The components provide suspension as well as control through their attachment to cables that operate locks for various joints and provide function for the terminal device. The figure-eight ring harness is one of the most common and provides suspension and control of prosthesis. The figure-nine harness supplies only control, as the Müenster socket provides suspension ( Fig. 7-2 ).






    Fig. 7-2Cross-point of harness connected by stainless steel ring. (From Below and Above Elbow Harness and Control System, Evanston, IL, 1966, Northwestern University Prosthetic-Orthotic Center.)



  • terminal devices: hands, hooks, or other tools for various functional activities affixed to the wrist unit, affording function and cosmesis.




    • hands: a number of functional and passive hands are available. The mechanically functional hand provides prehension through several options. Options include a voluntary opening hand, voluntary closing hand, or myoelectrically controlled hand. A cosmetic glove matched to the patient’s skin color is applied externally. In addition to providing increased cosmesis, passive hands are extremely functional in terms of stabilizing objects during bimanual activities. Some specific hands are: Dorrance voluntary-opening hand, Sierra voluntary-opening hand, APRL voluntary-closing hand, soft voluntary-closing hand, Becker locking grip hand, and CAPP terminal device.



    • hooks: Prosthetic hooks have lyre or canted fingers, rubber bands, and a ball terminal attachment for the cable system. Lyre-shaped hooks provide a “straight approach” to pick up different objects. The lyre shaped hook allows for fine point prehension (such as picking up a needle), but the individual’s line of sight is slightly obstructed. Canted shape hooks allow for a “side approach” for prehensile activities, such as using a pencil, and allows for better line of sight for the individual. Hooks are available in numerous sizes, generally in aluminum with Plastisol covering for children, aluminum or stainless steel with neoprene or nitrile lining, stainless steel with serrated inner finger surface such as the model 5X, and for heavy-duty tasks the 7 or 7LO (large opening) types (farmer’s hook), designed to hold devices such as shovels or rakes. Although certain hooks differ, such as the Army Prosthetics Research Laboratory (APRL) types, most use rubber bands or springs to close (voluntary opening), and prehension is directly proportional to the strength and number used. Other devices are model 8x small adult, model 10 children, model 12P infants, mitts, and N-Alber II for task-specific tool interchange. Hooks may also be classified as voluntary closing, where the individual controls the force of grip during prehensile activities. Voluntary closing hooks involve more complexity of use compared to a voluntary opening terminal device.




  • wrist flexion unit: allows prepositioning of terminal device closer to the midline of the body; generally used for the bilateral patient.



  • wrist units: integral components at the distal end of the prosthesis that allow attachment, interchangeability, and pronation and supination of the terminal devices. Types are standard, constant friction, and quick change; units are oval or round to match the distal anatomic aspect of the residual limb.



Lower Limb Prostheses and Components


( Fig. 7-3 )






Fig. 7-3A patellar tendon-bearing exoskeletal prosthesis with supracondylar cuff and solid ankle cushioned heel foot.


Lower limb prostheses are external systems designed for the amputation levels from the partial foot level distally to the hemipelvectomy level proximally. They are categorized as exoskeletal or endoskeletal. The exoskeletal prosthesis has a rigid outer shell that provides structural strength and cosmetic shape. The endoskeletal prosthesis has a tubular structure connecting the components and is covered by cosmetic foam. The primary components of the prosthesis are the socket, suspension system, foot, and knee unit. This terminology is different from that used by surgeons in describing the amputation levels.




  • Chopart: distal to the ankle joint. Correct with distal weight-bearing socket with partial foot replacement.



  • foreshortened prostheses: short lower-limb prosthesis, typically for bilateral above-knee amputations that do not include knee units. Designed to increase stability during initial ambulation by lowering the individual’s center of gravity. Also called stubbies’.



  • hemipelvectomy: amputation at hip level with ablation of the ischial tuberosity. Correct with plastic socket designed to distribute weight using remaining musculature, rib margin, cosmetic socket build-up, mechanical hip and knee joints, and prosthetic foot.



  • hip disarticulation (HD): amputation at the hip level but with the ischial tuberosity intact. Correct with plastic socket designed to transpose weight through the ischial tuberosity and related gluteal musculature, mechanical hip and knee joints, and prosthetic foot.



  • Jaipur foot: foot device using readily available materials attached to end of prosthesis for barefoot individuals. The prosthesis is a modification of the Solid Ankle Cushioned Heel (SACH) Foot, is inexpensive, and can be made in 1 hour. It enables individuals to work in rural conditions and muddy, wet fields, and to climb trees. It has been widely used in India, southeast Asia, and Africa, where local variations to the design have now been made.



  • knee disarticulation: amputation through the knee joint. The socket is self-suspending with either a medial opening or a soft liner to facilitate donning. A Silesian belt can be worn as an auxiliary suspension. There is also a polycentric (four-bar linkage) knee unit and prosthetic foot. End-bearing leather or plastic sockets with external hinges, fork straps, and waist belts are still in use. Also called knee bearing (K/B).



  • Lisfranc: a disarticulation through the medial metatarsophalangeal joint or metatarsal-tarsal joints. Correct with extended steel shank in shoe to provide a place to push off and toe filler or foot plate with toe filler.



  • Syme: through the ankle joint; results in a bulbous distal weight-bearing residual limb. Correct with a medial-opening or expandable-wall prosthesis, which facilitates application and removal. Weight-bearing is distributed between the distal end and the patellar tendon. The socket is self-suspending because of the reduced circumference above the distal limb.



  • transfemoral: formerly called above knee, it is proximal to the knee joint but distal to the hip joint. Correct with quadrilateral or narrow medial-lateral ischial containment socket prosthesis.




    • computer-assisted design/computer-assisted manufacturing (CAD-CAM): refers to the contour of the socket and how it is modified. It is a handmade, computer-assisted method of providing a cosmetically accurate fit that can use any of the ischial containment sockets.



    • ischial containment sockets: a transfemoral amputation socket design incorporates a narrow M/L shape, high lateral wall, and a slanted pocket to encompass the ischium. Provides greater control of lateral forces during gait and a more even distribution of proximal weight-bearing areas. Also called narrow medial-lateral and contour adducted trochanteric controlled alignment method (CAT-CAM).



    • quadrilateral ischial weight-bearing socket: wooden or plastic socket designed with a shelf to transpose weight through the ischial tuberosity; suspension may be achieved by a hip joint with a pelvic band and control belt or with a suction socket.




  • transtibial: formerly called below knee, it is proximal to the ankle but distal to the knee. Correct with patellar tendon–bearing (PTB) or total surface-bearing (TSB) socket. The PTB is designed to bear weight through the patellar tendon, medial tibial flare, and other pressure-tolerant areas; socket may be hard or have a soft liner, and serves as a suspension as well. A TSB socket requires an additional suspension mechanism such as a gel liner or suction socket.




    • joint and corset: for the patient with mediolateral instability of the knee, for a very short below-knee amputation, or for residual limb incapable of supporting total body weight because of conditions such as burns and skin-adherent tissue. A typical prescription is as follows: PTB type of socket, external mechanical knee joints, thigh corset, fork strap, waist belt, and prosthetic foot.



    • suction socket suspension: for transtibial prosthesis, a design of suspension that incorporates a valve, silicone and other materials for a liner, and suspension sleeve to stabilize the residual limb in the socket without volume fluctuation. The silicone liner may incorporate a liner with a silicone ring to achieve socket suction without having to apply the suspension sleeve. Differs from PTB type.



    • supracondylar (PTB-SC): PTB with supracondylar stability incorporates higher medial and lateral walls that encompass the femoral condyles. A medial wedge, either movable or built into a soft liner, is placed firmly over the medial epicondyle.



    • supracondylar-suprapatellar (SC-SP): similar to supracondylar but also includes a high anterior wall that encompasses the patella. This provides increased suspension and increased surface area to decrease pressure on the residual limb, and limits hyperextension of the knee.




Lower Limb Prosthetic Components





  • below-knee suspension: used to support below-knee prostheses.




    • billet: connects supracondylar cuff to waist belt.



    • condylar cuff: mediolateral attachment to a transtibial prosthesis with strap proximal to femoral condyles.



    • fork strap: anterolateral attachment to prosthesis connecting to waist belt.



    • suction socket: cushion liners are used for suction prosthetics and are worn directly over residual limb. Can assist in achieving suction by adding a vacuum to the socket, or by adding a suspension liner over the cushion liner and socket to achieve suction suspension.



    • supracondylar cuff: tabs that attach mediolaterally to prosthesis with cuff strap going around knee proximally to femoral condyles.



    • waist belt: webbing wrapped circumferentially at pelvis with connection to billet or fork strap.




  • foot and ankle components: allow normal gait patterns. There are five clinical categories of prosthetic feet designed according to the level of activity of the wearer:




    • dynamic response foot: curved metal strip that brings about spring action to assist in toe-off.



    • energy storing feet: incorporates a cushioned heel with a resilient toe lever that stores energy in stance phase and releases it at toe-off. Typically lighter than a solid ankle cushioned heel (SACH) foot.



    • microprocessor-controlled foot/ankle systems: allows the foot to accommodate for uneven terrain with a computer-controlled hydraulic unit.



    • multiaxial ankle: allows plantar flexion and dorsiflexion, and inversion and eversion. It is the traditional SACH foot with sides to flex.



    • SACH foot: solid ankle cushioned heel has no moving parts and is the most basic prosthetic foot available.



    • single-axis ankle: allows anteroposterior motion and controlled plantar flexion with dorsiflexion stop.




  • hip disarticulation or hemipelvectomy suspension: webbing over shoulder on sound side with anteroposterior socket attachments.



  • knee disarticulation suspension: the most common type of suspension for a knee disarticulation patient is self-suspension over the femoral condyles or suction, then a total elastic suspension belt, not a waist belt.



  • knee prosthetic components: designed to provide stability during early and middle stance phases and bend in late stance and swing phase, as well as in kneeling and sitting.




    • external: most common application in knee bearing; no controlled friction.



    • fluid-controlled knee (hydraulic or pneumatic): provides swing phase control for a variable rate of gait, eliminating excessive heel rise and terminal impact. Varieties include Dupaco, Dynaplex, Daw, Otto Bock, and Mauch.



    • four-bar linkage: a polycentric system that is inherently stable, this unit can be adjusted to change the instantaneous center of rotation during dynamic alignment.



    • hybrid knee: combined polycentric knee with pneumatic fluid-control cylinder component.



    • manual locking knee: knee automatically locks at full extension. Patient-controlled lock disengages for sitting.



    • microprocessor knee: electronic sensors monitor the actions of a hydraulic unit during swing and stance phases.



    • powered knee: a microprocessor knee that can generate powered knee motion.



    • safety knee: weight-activated stance control. When knee is extended and weight-bearing, an adjustable braking mechanism is activated to resist flexion.



    • single axis knee: single point of rotation with constant friction to control swing phase.



    • swing and stance knee (S n’ S): a hydraulic knee unit that can be adjusted to control resistance during swing and stance phases of gait




  • transfemoral suspension: used to suspend above-knee prostheses.




    • control belt: leather wrapped circumferentially at pelvis and attached to pelvic band.



    • pelvic band: mechanical free-motion joint positioned anatomically on lateral wall of socket with a metal band contoured to the pelvis and attached to the upright of the hip joint. Also called hip joint.



    • shoulder harness or suspenders: webbing straps traversing shoulders with roller and cord or various attachments to socket.



    • Silesian bandage or belt: webbing over hip on sound side with one lateral and two anterior socket attachments. Used in conjunction with a looser-fitting suction socket.




Other Components, Materials, and Techniques





  • cast sock: used to take negative plaster impressions; sometimes used with or in place of residual limb socks; especially applicable for the new transtibial amputations during volume reduction of the residual limb.



  • check socket: an adjustable, clear plastic socket used to ensure proper fit before definitive fabrication; also called test sock.



  • distal end pad: injection of Silastic or an equivalent foam into end of socket of below- or above-knee systems; provides total contact distally and reduces possibility of edema.



  • donning sleeve: for transfemoral amputation, a tubular cotton or nylon material allowing the patient to don suction socket of the prosthesis during volume reduction of the residual limb.



  • extension aid: to assist knee extension in the above-knee prosthesis.



  • pylon: height-adjustable tubular component that connects the socket and prosthetic foot (endoskeletal construction).



  • residual limb-compression garment: compression sleeve worn on residual limb to reduce volume.



  • rigid dressing: device worn on residual limb to reduce volume, protect the residual limb during transfers, and desensitize the limb. A rigid dressing can be fabricated using plaster, fiberglass, or plastic.



  • rotator unit: component in the prosthesis designed to compensate for shear forces, thereby reducing torque and friction between the residual limb and interface of the socket; also called torsion unit.



  • sheath: nylon interface worn between residual limb and residual limb socks to reduce shear forces.



  • silicone gel socket insert: inner liner made of silicone gel designed to absorb shear forces. Suspension sleeve: neoprene, gel, or latex sleeve worn over proximal portion of the prosthesis and extending onto the patient’s thigh. Provides suction suspension.



  • socket: custom-fabricated component into which the residual limb fits.



  • soft cosmetic cover: foam material covering endoskeletal components; shaped cosmetically.



  • soft socket insert: soft inner liner for a patellar tendon–bearing socket. Silicone gel is most commonly used.



  • sock: wool or cotton sock worn over residual limb to provide a cushion for friction between skin and socket interface. Available in various plies (thicknesses) from the thinnest (1 ply) to the thickest (6 ply).



  • total contact: for transtibial amputation intimacy between socket and residual limb, particularly at distal end, to control edema.



Specialized Systems





  • immediate post-operative prosthesis (IPOP): procedure performed immediately after surgery; patient is fitted with plaster type of socket, adjustable pylon, and prosthetic foot. Advantages include early weight-bearing, standing, ambulation, protection of the residual limb, and psychologic benefits.



  • intermediate prosthesis: thermoplastic type of socket with adjustable pylon and prosthetic foot; intermediate phase of management used to expedite fitting, establish early ambulation, and reduce volume of residual limb prior to definitive fitting. Also called temporary prosthesis.



  • modular prosthesis: selectively applicable for below-knee or any level of proximal amputations; use socket according to prescription with adjustable pylon and foot and socket attachment plates; exterior surface is made of custom-shaped foam and covered with cosmetic material. Also called endoskeletal prosthesis.



  • osseointegration: An artificial implant is inserted into the bone of the residual limb surgically. This implant allows prosthesis to be directly attached to the residual limb.



Orthoses


An orthosis is an externally applied device designed to provide control, correction, and support and decrease of deformity. The orthosis can either resist or assist motion to control deformity, to unweight a body segment by force reduction, and provide corrective measures.


The Task Force on Standardization of Prosthetic-Orthotic Terminology of the Committee on Prosthetic-Orthotic Education, National Research Council, and the AOPA have been largely responsible for the implementation of the terminology generally in use today. In an effort to enhance communication between the prescribing physician and the orthotist, the following descriptive guidelines have been adopted. The standardization is based on indicating those joints and regions that the orthosis is to encompass or control. The orthosis controls the named joint by allowing free, assisted, or resisted motion. Orthosis types are as follows:




  • AFO: ankle-foot orthosis



  • AO: ankle orthosis



  • BFO: balanced forearm orthosis



  • CO: cervical orthosis



  • CTLSO: cervicothoracolumbosacral orthosis



  • CTO: cervicothoracic orthosis



  • EO: elbow orthosis



  • EWHO: elbow-wrist-hand orthosis



  • FO: foot orthosis



  • HKAFO: hip-knee-ankle-foot orthosis



  • HdO: hand orthosis



  • HpO: hip orthosis



  • KAFO: knee-ankle-foot orthosis



  • KO: knee orthosis



  • LSO: lumbosacral orthosis



  • PRO: pressure-relieving orthosis



  • PTBO: patellar tendon–bearing orthosis



  • SEWHO: shoulder-elbow-wrist-hand orthosis



  • SIO: sacroiliac orthosis



  • SO: shoulder orthosis



  • SOMI: sternooccipital mandibular immobilizer



  • TLSO: thoracolumbosacral orthosis



  • TO: thoracic orthosis



  • WAWHO: wrist-action, wrist-hand orthosis



  • WDWHO: wrist-driven, wrist-hand orthosis



  • WHO: wrist-hand orthosis



Use of the foregoing terms leaves the materials, design, and components to the discretion of the orthotist, unless otherwise indicated by prescription, as demonstrated in the following examples.




  • Prescription: AFO to provide dorsiflexion assist. (This simple prescription leaves orthotic management regarding materials for the system to be determined by the orthotist according to patient evaluation.)



  • Prescription: AFO to provide dorsiflexion assist; double metal uprights, Klenzak ankle joint, calf band, Velcro closure, and shoe attachments.



  • Prescription: AFO to provide dorsiflexion assist; thermoplastic fabrication.



As demonstrated, this format provides the prescribing physician with various controls over the patient’s management.


Lower-Limb Orthoses


Because all orthoses currently in use are too numerous to discuss, we confine our list to those most commonly prescribed.


Foot Orthoses





  • club foot o.: consists of a rigid bar riveted or clamped to shoes at either end. The bar provides hip abduction with ratchet adjustments controlling rotation; generally prescribed for treatment of clubfoot, equinovarus, pes planus, or tibial torsion. These systems allow for more independent control and leg movement with infant able to crawl because of jointed bars. Also called Dobbs bar, Ponseti bar, and Denis Browne bar.



  • flexible o. (accommodative orthosis): providing longitudinal arch and metatarsal support; orthosis is removable from shoe. The goal of flexible foot orthoses are to accommodate and support the current position of the foot, especially regarding rigid deformities.



  • hallux valgus o.: reduces bunion pain by decreasing valgus deformity (pulls toe to midline of body).



  • rigid corrective o.: carbon composite fiberglass and stainless steel designed to provide arch support for pes planus or other related problems of a flexible foot deformity; orthosis is removable from shoe.



  • UCBL o.: (developed at the University of California Biomechanics Laboratory) similar to the rigid foot orthoses, but trimlines are more proximal to increase stability and correction of the heel.



Ankle Orthoses





  • elastic o.: provides minimal support, acts as a kinesthetic reminder and helps control swelling.



  • leather gauntlet o.: leather, canvas, or equivalent material provides substantial immobilization of the ankle to alleviate pain caused by motion.



Ankle-Foot Orthoses





  • Charcot restraint orthotic walker (CROW): rigid orthotic with rocker bottom foot; inner aspect lined with foam with a dual-density custom insert to stabilize and prevent further deformity of the foot.



  • conventional o.: fitted ¾-inch distal to head of fibula and is an integral part of the shoe; examples are single or double upright jointed ankle, free motion, limited motion, and dorsiflexion assist; used with calf band, buckle, or hook-and-loop closure and stirrup with shoe attachments. Indicated for patient populations that have fluctuating levels of edema.



  • double adjustable ankle joint (DAAJ): ankle motion can be adjusted to lock, limit, or provide assistance (via springs) for various flexion and dorsiflexion ranges of motion.



  • floor reaction o.: most designs mimic a solid-ankle AFO (regarding the ankle), and does not allow plantar or dorsiflexion. Plantarflexion can only be permitted if the orthosis is articulated with adjustable joints. Also called ground reaction AFO.



  • patellar tendon–bearing (PTB) o.: weight-bearing terminates just proximal to the patellar tendon and is fitted around the knee similar to the below-knee prosthetic socket; used with molded foot plate or ankle joints and stirrup with shoe attachments; designed to transmit body weight through the patellar tendon and medial femoral condyle to achieve controlled unloading of weight on the tibia and ankle-foot complex; anteroposteriorly sectioned proximally.



  • spring wire o.: medial and lateral spring wire uprights attached to calf band proximally and the shoe distally; designed to provide dynamic dorsiflexion assist.



  • thermoplastic o.: terminates at or near the apex of the gastrocnemius muscle proximally, with molded foot plate fitted into shoe distally; ambulatory, nocturnal, or combination of both; designed to control and correct specific problems of the foot-ankle complex.



Knee Orthoses





  • dynamic o.: similar to static with the addition of external knee joints with or without locks to allow controlled motion.



  • elastic knee o.: elastic sleeve encompassing the knee; provides minimal support and stabilization. Variations are the following:




    • medial and lateral contoured knee joints: similar to elastic knee o., with the addition of joints providing some increased stabilization. Other options include medial and lateral condylar pads, adjustable anterior laces, and additional spiral control straps.



    • Swedish knee cage: metal frame and padded strap system allowing flexion but preventing hyperextension (recurvatum) of the knee.




  • ligamentous control o.: commercially available custom-fabricated and custom-fit designs to control special ligamentous deficiencies about the knee.



  • static o.: Metal, thermoplastic, or equivalent; immobilizes knee in selected degree of flexion or extension.



Knee-Ankle-Foot Orthoses





  • metal o.: KAFO that can be either single or double upright with an adjustable ankle joint (free motion, limited motion, or dorsiflexion assist). Components include a calf band, distal and proximal thigh bands, and buckle or hook-and-loop closures, with or without lock, stirrup, and shoe attachments.



  • thermoplastic o.: orthosis fabricated of plastic material with molded foot plate fitted into shoe distally. This type of system has found increased acceptance because of its lighter weight and total contact fitting capabilities.



Other specialized KAFOs include those designed to manage patients with neuromuscular conditions and fractures using plaster or plastic with polycentric knee joints and other sophisticated components.


Hip Orthoses





  • abduction o.: bilateral thigh cuffs of plastic, covered metal, or equivalent with adjustable bar to provide hip abduction, and waist belt and/or thoracic section to maintain positioning. Some systems have additional adjustment for hip flexion control. Also called Ilfeld splint.



  • A-frame o.: for Legg Calvé Perthes disease, this system is used with an extra-long bar to treat developmental dysplasia of the hips. An A-frame orthosis is sometimes incorporated to control the tendency for genu valgum (knock-knee), which may occur because of extensive hip deformity.



  • Atlanta brace: for Legg Calvé Perthes disease, a hip abduction brace that allows ambulation without crutch assistance.



  • Barlow splint: for dysplastic hips in infants; an abduction, flexion, external rotation splint. Also called Malmo splint.



  • Ferrari o.: for patients with high level weakness due to spina bifida; a combined thoracic lumbar orthosis with full lower limb orthosis.



  • Louisiana State University reciprocating gait o.: for spinal cord injuries; a cable-driven brace that allows for support while the flexion of one lower limb drives extension of the other.



  • Newington o. : for Legg Calvé Perthese disease bilateral and similar in design to the Toronto o.; differs in that flat bars are used, and no joints are incorporated (i.e., without knee motion).



  • Pavlik harness: a series of straps passing over the shoulders, abdomen, and lower limb to properly position the femur head into the acetabulum for proper growth formation. Alignment goal is to provide hip flexion, abduction, and external rotation.



  • pillow o.: soft splint fitted between the thighs to provide hip abduction with straps over the shoulders to maintain positioning; also called Frejka o.



  • Salter sling: for Legg Calvé Perthes disease, sling device that holds hip in abduction and internal rotation while the knee is held flexed.



  • Scottish Rite o.: for Legg Calvé Perthes disease, pelvic band, bilateral free-motion hip joints, proximal thigh cuffs, and adjustable thigh bar with universal joints at inferior medial aspect of cuffs; ambulatory system providing hip abduction.



  • sitting walking and standing hip (SWASH) brace: for cerebral palsy; orthosis with a pelvic wrap, rods, and mid-thigh cuffs designed to prevent hip dislocation.



  • thermoplastic/metal o.: custom-fabricated system designed to maintain the hips in degrees of flexion, abduction, and rotation, as prescribed.



  • Toronto o.: for Legg Clavé Perthes disease, bilateral proximal high cuffs, center tubular column with universal multiaxial joints at base, outriggers with angled mounting blocks at either end to receive attachment of shoes, allows hip and knee movement; ambulatory system providing hip abduction and controlled rotation.



  • trilateral o.: for Legg Calvé Perthes disease, plastic quadrilateral socket fitted at the level of the ischium similar to that of a transfemoral prosthetic socket. Composed of a single upright with shoe attachment and is designed to provide unilateral weight unloading, hip abduction, and internal rotation. Also called Tachdjian o.



  • Von Rosen o.: for developmental dysplasia of the hip in infants and very young children; passive motion restraint in abduction and flexion.



Hip-Knee-Ankle-Foot Orthoses


The following orthoses, except for the reciprocating gate orthosis and standing frame type, are described in a unilateral application, although they can be fitted bilaterally.




  • cable twister o.: pelvic belt with free-motion hip and ankle joint, plastic-covered cable, connecting joints, stirrup, and shoe attachments; calf and thigh bands are incorporated as necessary; adjustable at hip and ankle to provide dynamic control of hip rotation and tibial torsion.



  • elastic twister o.: rarely used; pelvic belt with elastic straps wrapped around leg and attached to a hook in the shoe; provides dynamic control of hip rotation and tibial torsion.



  • reciprocating gait o. (RGO): provides support to lower limbs and trunk for patients with paraplegia; an orthosis that has a gear box or cable system attached to bilateral knee-ankle-foot o. and contoured lumbosacral section, allowing a lower-level paraplegic to have a reciprocating gait.



  • standard o.: standard, thermoplastic, metal, or combination of materials used in any of the knee-ankle-foot orthoses to which has been added a pelvic band that is static or with a mechanical hip joint for dynamic control of the pelvis.



  • standing frame o.: thoracic component, pelvic band, lateral uprights attached to platform base, which has slots to accept patient’s shoes, uprights are generally overlapped to allow growth adjustment. Some type of control is used for knee extension. Joints are optional at hips and knees. This system is used to achieve standing for patients whose conditions may confine them to a wheelchair or bed for most of the day.



  • Steeper advanced reciprocating gait o.: for spinal cord injuries; a cable-driven brace that allows for support while the flexion of one lower limb drives extension of the other.



Components Applicable to Lower Limb Orthoses





  • ankle, knee, or hip joint: mechanical axis placed anatomically over a joint axis to allow or control motion.



  • Bail lock: posterior spring-loaded ring extending from medial to lateral knee joints with capability of automatic locking and patient activated unlocking for sitting.



  • calf band: metal covered with leather or equivalent fitted to the calf area on conventional ankle-foot or knee-ankle-foot orthoses.



  • dial lock: may be set in varying degrees of flexion or extension to accommodate or reduce contractures; other comparable types.



  • distal thigh band: lower thigh band on knee-ankle-foot orthoses.



  • double-action ankle joint: anterior and posterior compartments provide infinite adjustment for solid, limited, or dynamic assist with the use of interchangeable pins and springs.



  • drop-lock ring: rings slide over joint at the knee to maintain extension. Rings allow the joint to be manually unlocked to achieve knee flexion for sitting.



  • extended steel shank: inserted in sole of shoe to or past metatarsal heads to more effectively reduce force on the plantar aspect of the foot during gait.



  • floor reaction ankle foot o.: custom thermoplastic orthosis, commonly with plantar flexed position and anterior upper leg bar that forces knee to extension on floor reaction force.



  • ischial weight-bearing ring or band: metal component covered with soft material and fitted at the level of the ischial tuberosity to partially unload weight from the lower limb; also called Thomas ring.



  • Klenzak o.: dorsiflexion assist or plantar flexion resistance for ankle joint; spring-loaded dynamic assistive control of the foot.



  • lateral spring-loaded lock: for transfemoral amputees; a spring-loaded ring lock with lever that dynamically locks at full extension. There are also pneumatic and hydraulic extension-assist devices available.



  • limited- or free-motion ankle joint: permanently adjustable to allow motion as desired.



  • metal foot plate: similar to New York University insert but fabricated of stainless steel, Monel, or equivalent.



  • New York University (NYU) insert o,: metal o. using thermoplastic foot plate attached to ankle joint stirrups; provides correction of the foot and allows various shoes to be worn.



  • overlapped upright or growth extensions: uprights placed on top of one another to accommodate growth in children.



  • patellar pad: leather or equivalent; fits over patella with straps around uprights to maintain knee extension.



  • proximal thigh band: most proximal thigh band on knee-ankle-foot orthoses.



  • quadrilateral brim: similar to ischial weight-bearing ring but fabricated with thermoplastic.



  • split stirrup: component mounted in the heel of various shoes to allow interchangeability of conventional (metal) orthoses.



  • spreader bar: attached medially to both stirrups of bilateral knee-ankle-foot orthoses to prevent uncontrolled abduction.



  • stirrup: component of conventional lower limb orthoses connected distally in the shoe and attached proximally to the ankle joints of the orthosis.



  • suprapatellar and infrapatellar straps: small straps above and below knee, continuing around uprights to assist in maintaining knee extension.



  • upright: metal, plastic, or equivalent used to connect various other components.



  • valgus control modifications: medial or lateral total contact extension on thermoplastic KAFOs that assist in correcting or stabilizing genu varum or valgum; also called genu varum control modifications.



  • varus corrective ankle straps or valgus corrective ankle straps: soft, padded leather or equivalent components that wrap around the opposite side. Also referred to as a T strap because of the shape.



  • varus and valgus knee control pads: leather or equivalent components that wrap around an opposing upright to correct deformity.



Upper Limb Orthoses


Physiology in design considerations for hand and wrist-hand orthotic systems include the following:



  • 1.

    Maintain thumb in opposition for prehension.


  • 2.

    Allow for thumb abduction as may be required.


  • 3.

    Maintain skeletal stability.


  • 4.

    Avoid restrictions in use of the orthosis.


  • 5.

    Prevent or correct contractures.


  • 6.

    Maintain wrist in the functional 25 to 35 degrees of extension.



Because of infinite and intricate variety of systems, only a few common examples are given.


Wrist-Hand and Hand Orthoses





  • basic hand splint: for muscle weakness in the hand; a dorsal splint that wraps around the ulnar, distal, and volar side of the hand held in place with a strap around the distal wrist.



  • cock-up splint: one plastic section providing wrist extension with incorporation of a C bar for prehension or a soft hook-and-loop orthosis with palmar bar to extension the wrist.



  • dynamic finger splint: fitted to individual fingers to dynamically influence flexion or extension of a joint; also called safety pin o. and finger benders.



  • externally powered tenodesis o.: through activation of a microswitch, tenodesis graft is achieved using a mechanical muscle.



  • Galveston metacarpal brace: for distal metacarpal fractures; an adjustable brace that provides dorsally directed pressure on the distal component of the fracture with counter pressure on the mid-dorsum of the hand.



  • long opponens o.: identical to short opponens with forearm extension for wrist control.



  • palmar wrist splint: easily removable volar wrist splint that has molded palmar extension that helps hold thumb in functional position.



  • ratchet tenodesis o.: wrist-hand o. to passively lock hand in a grasp prehension for a partially paralyzed forearm and hand.



  • reciprocal finger prehension: for severe paralysis of forearm and hand; this orthosis allows patients to use their unaffected hand to adjust and set the fixed position of fingers.



  • short opponens o.: consists of radial extension, opponens bar, palmar arch, ulnar extension, and dorsal extension; fabricated of plastic or metal. Positions hand and thumb for opposition and does not influence the wrist.



  • wrist-driven wrist hand o. (WDWHO): opponens bar with jointed radial side with a connection between hand and forearm sections and thumb post. Wrist dorsiflexion produces a lateral prehension pattern using the mechanical axis.



Elbow Orthoses


Elbow orthoses may be static with humeral and forearm sections for immobilization, as in hand orthoses, and external joints to allow motion. Some are designed with turnbuckles or the equivalent to reduce contracture and may be static or dynamic.


Dec 24, 2021 | Posted by in ORTHOPEDIC | Comments Off on Prosthetics and Orthotics
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