PATELLAR TENDON BEARING PROSTHESIS

Dr. Madhusudhan NC

Resident-Dept. of Orthopaedic Surgery

Bangalore Baptist Hospital

History

• Invented in 1950’s (Even before we all were born)

• James Foort & Charles Radcliffe

• State of the art was the “plug fit” socket

Plug Fit

• Typically wood socket lined with leather

• Essentially a cylinder

• No provision for volume change

• Depth of limb engaged in socket was volume

dependent

PRESCRIPTION CRITERIA

1. A wide variety of amputees can wear.

2. To know who are not the candidates for PTB prosthesis……. We need to know the contraindications for PTB prosthesis.

3. Successful application described under 3 criterias.

1. Control.

2. Weight bearing.

3. Acceptance.

Co

ntr

ol…

….

1. Amount of stump available for leverage.

2. Condition of the stump musculature.

3.Neuromuscular function.

Wei

ght

bea

rin

g A

bili

ty…

.. 1. Strength of bone.

2. Joint function.

3. Presence or absence of pain.

4. Condition of skin in weight bearing areas.

5. Vascular state.

Acc

epta

nce

…. 1. Amputee’s

motivation.

2. His activity level.

PTB-Loading Pressure Tolerant Areas

• It was theorized that certain places on the residual

limb would be better at pressure dissipation and thus

• Could tolerate load better than other areas

• These were areas that contained

– Soft tissue

– Neurovascular areas

– Muscular areas

PTB-Loading Pressure Tolerant Areas

• Patella Tendon

• Anterior Muscular Compartment

• Medial Tibial Flare

• Lateral Stabilizing bar/ Shaft of Fibula

• Gastrocnemius muscle bellies

• Popliteal Fossa

• Distal end to some extent

PTB-Relieving Pressure Sensitive Areas

• If soft tissue and vascular areas can tolerate load, then

remaining areas must be less tolerant of load.

• This includes areas of

– Less vasculature

– Less soft tissue

PTB-Relieving Pressure Sensitive Areas

• Patella

• Lateral Tibial (Gerdy’s)Tubercle/Iliotibial Band

• Fibula Head/Common Peroneal Nerve

• Tibial Tubercle

• Tibial Crest

• Distal cut end of Fibula/Tibia

• Hamstring Tendons

We’ll discuss in brief how exactly it has been done.

Concepts:

1. Parts.

2. Shank?

3. Foot Assembly

4. Alignments.

So we have socket ready with us…,

Let us select the Foot assembly.

Options!

1. SACH foot.

2. SAFE (Stationary Attachment Flexible Endoskeleton) foot.

3. STEN (Stored Energy)

4. Carbon copy.

5. Quantum foot.

6. Seattle….,Flex foot….,Springlite…..,Jaipur foot.

One End we have Socket….,the other end Foot…

Connected by. “Shank”

Shank

1. Exoskeleton.

2. Endoskeleton.

* Strength

* Cost

* Cosmesis

Needs Suspension.

Options:

1. Mulleys strap/ Condylar cuff suspension.

2. PTBSCSP

3. Sleeve suspension.

4. Silicone suction socket.

5. Thigh corset.

6. Waist bell.

To remember…

1. Parts.

2. Weight bearing and relieving.

3. Types of foot assembly, shank,suspension.

THANK YOU