OPC Prosthetics Written cheat sheet

Residual limb length is measured from the nearest proximal bony landmark (e.g., tibial tuberosity, ischial tuberosity) to the distal end; record in cm with the joint position specified.

Vascular assessment: palpable pulse grading 0-4+, ankle-brachial index <0.9 suggests peripheral arterial disease; non-healing wounds or rest pain warrant referral before prosthetic fitting.

Volumetric and circumferential measures should be taken at consistent landmarks and times of day; diurnal volume change of 3-5% is common in mature limbs.

Manual muscle testing uses the 0-5 scale; a grade of 3/5 (antigravity) is generally the minimum for effective prosthetic control of a given muscle group.

Sensation testing: light touch, pinprick, and two-point discrimination; protective sensation loss increases skin breakdown risk under a socket.

Transfemoral assessment includes ischial tuberosity and greater trochanter palpation, hip flexion contracture measurement (Thomas test), and residual limb circumference at set intervals.

Upper limb assessment documents shoulder range of motion, contralateral limb dominance, and bilateral prehension needs before component selection.

Comorbidity and cognition screening (e.g., MMSE, Berg Balance Scale) informs candidacy and prosthetic potential; document K-level descriptors for lower limb candidates.

K-level 0: no ability to ambulate or transfer; K1: household ambulator with fixed cadence; K2: limited community ambulator; K3: community ambulator with variable cadence; K4: high-impact, high-energy user.

Medicare functional K-level determines component category; K3 and above generally requires variable-cadence capability and higher-activity components.

Socket design decision: patellar tendon-bearing (PTB) for transtibial with patellar tendon weight bearing; total surface bearing (TSB) or hydrostatic designs distribute load circumferentially.

Suspension options for transtibial: pin/lock, suction, vacuum-assisted, cuff, sleeve; choice depends on limb volume stability, length, and hand function.

Transfemoral suspension: quadrilateral vs. ischial containment (MAS) socket; ischial containment affords better lateral stability and coronal plane control.

Prosthetic foot selection: SACH for K1-K2, energy-storing for K3-K4, multiaxial for uneven terrain; heel stiffness affects knee stability in early stance.

Knee unit selection: single-axis, polycentric, or microprocessor; stance-control knees are indicated for patients with weak quadriceps or high fall risk.

Upper limb terminal device: voluntary opening vs. closing, body-powered vs. myoelectric; body-powered offers proprioceptive feedback and durability, myoelectric offers grip force and cosmesis.

Negative cast is taken with the limb in a specific position; for transtibial, the knee is held in slight flexion and the cast is modified with reliefs over the patella, tibial crest, and fibular head.

Positive model modification: build-ups relieve pressure-sensitive areas; reductions create weight-bearing areas; the patellar tendon bar and popliteal shelf are key transtibial modifications.

Check socket (test socket) fitting precedes definitive fabrication; verify total contact, suspension, and alignment before lamination.

Lamination: acrylic resin with fiberglass or carbon reinforcement; vacuum-assisted lamination reduces voids and improves strength-to-weight ratio.

Bench alignment uses standard reference lines (e.g., trochanter-knee-ankle line for transtibial; the socket is set in 5 degrees of flexion); dynamic alignment follows at delivery.

Endoskeletal vs. exoskeletal: endoskeletal uses a pylon and cosmetic cover, allows alignment adjustment; exoskeletal is laminated directly and is more durable but heavier.

Socket volume management: flexible inner socket with rigid frame allows accommodation of volume change; check for distal residual limb contact and proximal brim pressure.

Fabrication tolerances: socket circumference should match cast measurements within 0.5 cm; check for pistoning, rotation, and excessive distal pressure before delivery.

Residual limb volume stabilizes over 12-18 months post-amputation; interim sockets are commonly required during this period.

Socket fit should be reassessed at each visit: check for redness, skin breakdown, and distal edema; a properly fitting socket leaves a uniform, non-blanching redness pattern.

Prosthetic alignment adjustment is indicated for gait deviations: excessive knee flexion in stance suggests excessive foot dorsiflexion or socket flexion; excessive knee extension suggests plantarflexion or socket extension.

Prosthetic maintenance: check suspension components, foot wear, and pylon integrity at least annually; replace worn liners every 6-12 months depending on use.

Rehabilitation progression: gait training, balance, and energy expenditure assessment; a K3 ambulator should achieve variable cadence and community distances.

Contralateral limb surveillance: monitor for overuse injuries, especially in the sound limb of transfemoral amputees; address limb length discrepancy and gait asymmetry.

Documentation of follow-up should include socket fit, skin condition, gait observation, and functional outcome measures (e.g., L-Test, 6-minute walk test).

Referral triggers: persistent skin breakdown, uncontrolled pain, falls, or functional decline warrant reassessment of the prosthetic prescription.

Documentation must support medical necessity: include diagnosis, functional level, prosthetic prescription rationale, and outcome measures.

Medicare prosthetic coverage requires a physician's order and documentation of the patient's functional level; K-level assignment must be supported by clinical evidence.

Informed consent for prosthetic fitting includes discussion of risks, benefits, alternatives, and expected functional outcomes.

Infection control: follow standard precautions; clean and disinfect tools and casting equipment between patients.

Billing and coding: use appropriate HCPCS codes (e.g., L-code series) for prosthetic components; verify coverage and prior authorization requirements.

Patient records must be retained per state and payer requirements; HIPAA privacy and security rules apply to all protected health information.

Continuing education and credentialing (e.g., ABC or BOC certification) are required to maintain competence and licensure.

Scope of practice: prosthetists design, fabricate, and fit prostheses; they do not diagnose or prescribe medical treatment independently of the care team.

The prosthetist's primary obligation is to the patient's welfare; patient interests take precedence over financial or business interests.

Informed consent and honest communication: disclose material risks, benefits, and alternatives; do not misrepresent expected outcomes.

Confidentiality: protect patient information except as required by law or with patient authorization.

Conflict of interest: disclose any financial interest in products or facilities and avoid arrangements that compromise clinical judgment.

Competence and scope: practice only within one's training and refer when the patient's needs exceed that scope.

Advertising and representation: do not make false or misleading claims about qualifications, services, or outcomes.

Respect for colleagues and other professionals: collaborate with the rehabilitation team and do not disparage other practitioners.

Research and reporting: report adverse events honestly and maintain integrity in data collection and publication.