Re: Optimal BK stump length
Chris L Johnson
Description
Collection
Title:
Re: Optimal BK stump length
Creator:
Chris L Johnson
Date:
1/30/1999
Text:
On Fri, 29 Jan 1999 16:42:38 -0600 Greg Penfold < <Email Address Redacted> > writes:
>We are having a discussion with a local surgeon regarding the optimal
>length for BK amputation. Although most sources recommend a 12cm to 17cm
or
>5 to 7 bone length from the medial joint line, he has a manual which
>recommends an 18cm to 20cm length. I believe his source is the
University of
>Texas. Does anyone know of any published studies or textbooks which
analyze
>the pros and cons of different length stumps?
>
>Greg Penfold CPO
I have some direct experience with limb length and some general comments.
Most of you probably already know this, so please pardon me if I'm
preaching to the choir. Nevertheless, having been burned by text book
simple surgery more than once, I felt I had to say something.
My initial amputation was long at 30cm. This failed due to poor
management of soft tissue (unviable skin grafts and poor techniques), and
the fact that there remained so little soft tissue that there was poor
bone coverage. I was then revised to 18cm with again, poor results, this
time due to poor management of both soft and hard tissues. Another
revision brought me to about 17cm, this time by Ernest Burgess of the
Seattle area. His was a good job for sure, but I wish I had had an Ertle
procedure wherein the bone bridge was formed between tibia and fibula.
Alas, water under the bridge. I still cannot end bear much, but at least
I wasn't hacked.
Length is important because too little length limits the force an amputee
can impart to the socket via the distal end and more proximal anterior
and posterior surfaces. This is particularly true as regards the force
resulting from extension moment...when the quad muscles push the lower
leg into extension or resist flexion. The 5-7 recommendation is there
because it provides generally adequate clearance for prosthetic
components, and allows adequate lever arm length to do the above.
Length should not be viewed from a text-book simple perspective but
should consider a wide number of factors such as but not limited to
viability of the anatomy and limitation of prosthetic components.
If great lengths are made to save a couple of inches through skin grafts,
for example, yet the skin turns out to be a mess later, why not amputate
a bit higher if there is still reasonable lever length? If the nerves
are really messed up, you're asking for a pain history. If the bone is
raggedy, perhaps spurs will be the rule, as was with me. If the leg is
really short to begin with, perhaps going for a bit more length is worth
the risk.
By leaving a leg really long, if the vast majority of components can no
longer be used is it worth it?
Leg length should not be a function of the surgeons ego, for example,
when driven by the mentality that amputation is death and not
rehabilitation. I have been victim to both that and hack and whack
surgery due to inadequate training (amputation as just something minor
else to learn in med school).
I am 189cm tall (6 ft+) and have that 17cm BK. I have definable quad
muscles, in part due to length and a great socket fit and a great
interface (9mm Alpha). Would I be better off at 19 or 20 cm? Probably
yes, if I had adequate soft tissue coverage and bone bridge surgery for
more end bearing capability. The original surgeon shaved off a good deal
of my muscle because it was recommended by a text book. This leaves me
with too little material at the end, after atrophy is considered.
This is rambling and incomplete, but the point is, limb length is not a
text book issue but is rather much more complex.
Chris Johnson, Engineering Director,
College Park Industries, Inc.
<Email Address Redacted>
www.college-park.com
>We are having a discussion with a local surgeon regarding the optimal
>length for BK amputation. Although most sources recommend a 12cm to 17cm
or
>5 to 7 bone length from the medial joint line, he has a manual which
>recommends an 18cm to 20cm length. I believe his source is the
University of
>Texas. Does anyone know of any published studies or textbooks which
analyze
>the pros and cons of different length stumps?
>
>Greg Penfold CPO
I have some direct experience with limb length and some general comments.
Most of you probably already know this, so please pardon me if I'm
preaching to the choir. Nevertheless, having been burned by text book
simple surgery more than once, I felt I had to say something.
My initial amputation was long at 30cm. This failed due to poor
management of soft tissue (unviable skin grafts and poor techniques), and
the fact that there remained so little soft tissue that there was poor
bone coverage. I was then revised to 18cm with again, poor results, this
time due to poor management of both soft and hard tissues. Another
revision brought me to about 17cm, this time by Ernest Burgess of the
Seattle area. His was a good job for sure, but I wish I had had an Ertle
procedure wherein the bone bridge was formed between tibia and fibula.
Alas, water under the bridge. I still cannot end bear much, but at least
I wasn't hacked.
Length is important because too little length limits the force an amputee
can impart to the socket via the distal end and more proximal anterior
and posterior surfaces. This is particularly true as regards the force
resulting from extension moment...when the quad muscles push the lower
leg into extension or resist flexion. The 5-7 recommendation is there
because it provides generally adequate clearance for prosthetic
components, and allows adequate lever arm length to do the above.
Length should not be viewed from a text-book simple perspective but
should consider a wide number of factors such as but not limited to
viability of the anatomy and limitation of prosthetic components.
If great lengths are made to save a couple of inches through skin grafts,
for example, yet the skin turns out to be a mess later, why not amputate
a bit higher if there is still reasonable lever length? If the nerves
are really messed up, you're asking for a pain history. If the bone is
raggedy, perhaps spurs will be the rule, as was with me. If the leg is
really short to begin with, perhaps going for a bit more length is worth
the risk.
By leaving a leg really long, if the vast majority of components can no
longer be used is it worth it?
Leg length should not be a function of the surgeons ego, for example,
when driven by the mentality that amputation is death and not
rehabilitation. I have been victim to both that and hack and whack
surgery due to inadequate training (amputation as just something minor
else to learn in med school).
I am 189cm tall (6 ft+) and have that 17cm BK. I have definable quad
muscles, in part due to length and a great socket fit and a great
interface (9mm Alpha). Would I be better off at 19 or 20 cm? Probably
yes, if I had adequate soft tissue coverage and bone bridge surgery for
more end bearing capability. The original surgeon shaved off a good deal
of my muscle because it was recommended by a text book. This leaves me
with too little material at the end, after atrophy is considered.
This is rambling and incomplete, but the point is, limb length is not a
text book issue but is rather much more complex.
Chris Johnson, Engineering Director,
College Park Industries, Inc.
<Email Address Redacted>
www.college-park.com
Citation
Chris L Johnson, “Re: Optimal BK stump length,” Digital Resource Foundation for Orthotics and Prosthetics, accessed November 24, 2024, https://library.drfop.org/items/show/211149.
