3. Lower limb Weight relieving ORTHOSES
Made by: Armghan Anjum
Orthotist & Prosthetist
King Edward Medical University
Lahore

4. Weight relieving orthosis
The weight of the limb is taken by the orthosis and relieves the weight bearing stress on the skeletal structures. Commonly used are:
Ischial weight relieving orthosis
PTB weight relieving orthosis

5. Ischial Weight Relieving Orthosis
It is designed to transmit force from ischium to orthosis and through orthosis to ground. It consists of:
Ischial weight bearing area: Ischial seat bears weight like in quadrilateral socket of above knee prosthesis.
Stainless steel bar connected to external knee joint and connected to bottom by a stirrup. The stirrup is riveted to sole plate extending to metatarsal head with boot or rocker-bottom boot

7. Biomechanical Principle
Weight bearing in quadrilateral socket is maximal during heel strike but it drops significantly during push off. Heel clearance between heel and shoe should be a minimum of 3/8 inch, to give effective weight relief.
Orthosis with fixed ankle, locked knee, rocker bottom foot gives 90% or more weight relief.
Orthosis with fixed ankle, locked knee, boot with training gives 86% weight relief.
Orthosis with locked knee, fixed ankle, and boot without training gives 60% weight relief. This shows the importance of proper rehabilitation therapy.

8. Indications *Perthe’s disease Slipped femoral epiphysis TB hip
Fractures of femur with non-union
Severe osteoarthritis hip
*Perthes disease is a rare childhood condition that affects the hip. It occurs when the blood supply to the rounded head of the femur (thighbone) is temporarily disrupted. Without an adequate blood supply, the bone cells die, a process called avascular necrosis.

9. Patellar Tendon Bearing Weight Relieving Orthosis
Transmits the force from knee through patellar tendon through the uprights and shoe to the ground. For easy donning and doffing PTB cuff is bivalve and closed by rigid buckles or straps. The cuff should be in 10° flexion for effective weight bearing. Fixed ankle should be in 7 to 10° dorsiflexion. The best results are achieved with:
Fixed ankle
One inch heel clearance
Rocker bottom shoe

10. Indications for PTB Weight Relieving Orthosis
Short-term:
Healing of fracture calcaneum
Postoperative fusion about ankle
Painful condition of heel refractory to conservative management and contraindicated to surgery
Long-term:
Delayed non-union fractures of tibia
Avascular necrosis of body of talus
Severe degenerative arthritis of ankle and subtalar joints
Osteomyelitis of calcaneum
Diabetic ulceration foot
Sciatic nerve injury with insensitive sole of foot
Chronic and painful conditions that are not amenable to surgery

12. Thanks For Listening & Have A Nice Day