Date: Fri, 5 Dec 2003 12:27:06 -0600
Subject: Proximal tibia nonunion
From: Obremskey, William T
This 48 yo male was referred for consideration of other surgical procedures instead of a TKA (believe it or not). Pt is s/p medial opening wedge osteotomty that failed and revised to exfix that was thought to have healed and now has a varus proximal tibia nonunion. He recently had an I&D and 6 weeks of IV vanco for a positive MRSA culture at his I&D. Current ESR 8 and CRP is normal. Pt was a contractor and is now a social worker and a reasonable guy.
I think a proximal humeral blade plate placed medially w/ PICBG in addition to a bridging ex-fix for 4 weeks may work, or is an Ilizarov his only non-arthroplasy choice?
Any other thoughts?
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William T Obremskey MD MPH
Vanderbilt University
Orthopedic Trauma Division
Nashville, TN 37232-3450
Bill Obremskey
Date: Sat, 6 Dec 2003 02:56:57 +0500
From: Alexander Chelnokov
Hello William,
OWT> opening wedge osteotomty that failed and revised to exfix that was thought to have healed and now has a varus proximal tibia nonunion.
How loose/stable is the site now?
OWT> I think a proximal humeral bade plate placed medially w/ PICBG in addition to a bridging ex-fix fro 4 weeks may work, or is an Ilizarov his only non-arthroplasy choice?
If it is closer to hypertrophic nonunion, gradual correction with an Ilizarov-like fixator could be probably best option, and healing would be augmented by distraction osteogenesis. It it is loose, it may need site opening+grafting. I would prefer Ilizarov or hybrid fixator, and leave the knee mobile.
Best regards,
Date: Sat, 6 Dec 2003 01:07:19 EST
From: Krausepc
My vote: Ilizarov or Spatial Frame New oblique corticotomy from superior medial to inferior lateral. Correct translation and also dial in valgus to correct mechanical axis. Long leg alignment films would be helpful. If you use a plate, it may be more difficult to optimize his axis.
Peter Krause
LSU
Date: Sat, 6 Dec 2003 09:21:25 -0600
From: Frederic B. Wilson, M.D.
Bill, Alex, and Peter,
I agree with the Ilizarov/Spatial Frame idea with a couple of caveats. First, the fixation of the proximal fragment will be problematic for a couple of reasons (small area for pins/wires with large forces concentrated in that area; proximity to reflection of the joint capsule w/ resulting increased risk of septic arthritis). Second is the difficulty of maintaining posterior clearance for the frame to allow reasonable knee motion.
It might, therefore, be better to span the knee initially for several weeks to distribute forces. If the infection is cleared (as the labs suggest) and the "fluff" represents hypertrophic biology, then I would favor a gradual correction allowing distraction and translation osteogenesid to take place. These corrections are technically very demanding with an Ilizarov. They may also push the mechanical limits of the Taylor Spatial Frame (or rather the frame-bone interface) with a single proximal ring.
LIf you don't mind, I'd like to forward these films on to Charlie Taylor to see what he thinks.
Best regards,
Fred
Frederic B. Wilson, M.D.
Trauma & Adult Reconstruction
ETMC First Physicians - Orthopaedic Clinic
Tyler, TX, 75701
Date: Sat, 6 Dec 2003 21:28:45 +0500
From: Alexander Chelnokov
Hello Fred,
FBWMD> I agree with the Ilizarov/Spatial Frame idea with a couple of caveats. First, the fixation of the proximal fragment will be problematic for a couple of reasons (small area for pins/wires with large forces concentrated in that area;
So olive wires are most space-saving options.
FBWMD> proximity to reflection of the joint capsule w/ resulting increased risk of septic arthritis).
Despite wires at the level may be intracapsular, septic arthritis is exclusively rare complication.
FBWMD> Second is the difficulty of maintaining posterior clearance for the frame to allow reasonable knee motion.
AFAIK many western vendors produce 3/4 rings so what's a problem? Or one may overlap two hemi-rings to make 2/3 or 3/4 or some else arc. Since very old times the Ilizarov set included large arcs for wires at the proximal femur. Many years we use such arcs, just pediatric size, for proximal tibia/distal femur in adults.
FBWMD> It might, therefore, be better to span the knee initially for several weeks to distribute forces.
Looks superfluous to my mind but should be harmless.
FBWMD> osteogenesis to take place.
I'm with you.
FBWMD> These corrections are technically very demanding with an Ilizarov.
What do you mean?
FBWMD> They may also push the mechanical limits of the Taylor Spatial Frame (or rather the frame-bone interface) with a single proximal ring.
I bet that 4 olive wires 2 mm will do the job.
Best regards,
Date: Sat, 6 Dec 2003 10:40:42 -0600
From: Frederic B. Wilson, M.D.
Alex,
I think I basically agree with everything you said. I worry that even with 4 olive wires in the proximal fragment there is going to be a lot of torsional force during the correction. Granted this is subchondral bone, but still a concern. Our experience with wires that penetrate the joint reflection has not been quite as good as you allude to. Nevertheless, wires are often placed very proximal without problems.
What has been your experience with rates of correction and schedules? Do you subsequently bone graft after achieving correction or do you find it mostly unnecessary?
My caveats were thrown out mostly as points of consideration. I do like the idea of the 2/3 proximal ring. They can also be stacked to provide more rigidity.
Fred
Date: Sat, 6 Dec 2003 22:14:55 +0500
From: Alexander Chelnokov
Hello Fred,
FBWMD> with 4 olive wires in the proximal fragment there is going to be a lot of torsional force during the correction.
Do you mean torsion in sagittal plane?
FBWMD> Granted this is subchondral bone, but still a concern. Our experience with wires that penetrate the joint reflection has not been quite as good as you allude to.
What if insert one or two cannulated screws into the proximal fragment and place olive wires inside the screws?
FBWMD> Nevertheless, wires are often placed very proximal without problems.
Exactly.
FBWMD> What has been your experience with rates of correction and schedules?
No personal deviations - just common 1 mm/day in case of linear translation, and 1 mm/day at the cental axis in case of wedge diastasis. Of couerse if we plan to have regenerate. Otherwise the rate can be as soft tissue allows.
FBWMD> Do you subsequently bone graft after achieving correction or do you find it mostly unnecessary?
It is difficulty to estimate/progniose healing in the case since we can't definitely see whether it is pure hypertrophic nonunion which wouldn't require grafting. The healing should be monitored (x-rays each four weeks) and if in 2-3 month a significant defect is revealed it should be grafted.
Date: Sat, 7 Dec 2003 22:02
From: Bill Burman
References:
What if insert one or two cannulated screws into the proximal fragment >and place olive wires inside the screws?
Interesting idea Alex, nothing on medline - yet.
Date: Mon, 8 Dec 2003 19:25:05 -0600
From: Frederic B. Wilson, M.D.
This is Charlie Taylor's take on the proximal tibia nonunion case submitted by Bill Obremskey.
Fred
-----Original Message-----
From: Charles Taylor
Sent: Sunday, December 07, 2003 1:42 PM
To: Frederic B. Wilson, M.D.
Subject: Re: Proximal tibia nonunion
Dear Fred,
I have a case to do which is almost the clone of what you sent. I agree with you to span the knee with a single femoral ring (complete) for 6-8 weeks. Place a 2/3 ring just distal to the joint and apply 3 olive wire fixation to the proximal fragment and attach to the proximal side only of the 2/3 ring. The 3rd ring could be another complete ring about 15 cm distal to the 2/3 ring. I would use 3 6mm titanium half pins in the distal tibial fragment with a five hole Rancho above and below the ring and one pin at the ring, all in different planes.
The most proximal first wire would be from lat to med in the coronal plane slightly posterior to mid tibia. The second middle wire would be slightly post med to ant lat. The third wire would be significantly inclined in the coronal plane from post med to ant lat, emerging just lat to patellar tendon. This might be the rare case to use small frag washers with the two medial wires.
Initially I would reduce the osteotomy gradually with a bone velocity of 1mm/day. You will then have to make a judgment call to be happy with union with the original varus knee or to very gradually (0.25 mm/day) realign to put your mechanical axis at the Fujisawa point or just medial (2/3 Fujisawa).
The case could be run as a chronic or a rings first total residual.
Sincerely,
Charlie
Date: Tue, 9 Dec 2003 12:13:29 +0500
From: Alexander Chelnokov
Hello Bill,
>>What if insert one or two cannulated screws into the proximal fragment and place olive wires inside the screws?
BB> Interesting idea Alex, nothing on medline - yet.
Nothing controversial to basic sciences and common sense :-)
For similar purpose I've seen use of some massive cannulated implant,
which had to be impacted to the bone. Screws look much more attractive.
Date: Tue, 9 Dec 2003 20:26:54 EST
From: Tadabq
Alex
Interesting idea of putting tensioned wires for XF through cannulated screws but I'm not real clear on the perceived advantage or the situation in which it would be considered an advantage. Are you thinking that the wire would not cut out or into the bone and thereby have a lower rate of loosening? That would seem reasonable since the wire would tend to cut through the bone line a cheese knife to a greater extent than the screw cutting out. What would keep the bone from shifting along the wires since, presumably, the cannulation in the screws would have a larger diameter than the tensioned wire? Would it be the geometry of multiple wires or other? Would this be more or less likely to have problems with pin track infection?
TD
Date: Wed, 10 Dec 2003 08:36:52 +0500
From: Alexander Chelnokov
Hello Tom,
TAC> Interesting idea of putting tensioned wires for XF through cannulated screws but I'm not real clear on the perceived advantage or the situation in which it would be considered an advantage. Are you thinking that the wire would not cut out or into the bone and thereby have a lower rate of loosening?
Presumably if one would insert say 3 olive wires only and same wires but two of them through cannulated screws the latter would have more surface area so less pressure on bone-metal interface.
TAC> That would seem reasonable since the wire would tend to cut through the bone line a cheese knife to a greater extent than the screw cutting out.
Yes.
TAC> What would keep the bone from shifting along the wires since,
For instance the wire can be replaced with the olive one after insertion of the screw. Two opposite screws - two olives, at lateral and medial sides. Or the initial wires can be bent. Also angle between screws/wires matters so even pair of crossing smooth tensioned wires should work if scrwews/wires are not close to parallel.
TAC> Would it be the geometry of multiple wires or other?
What do you mean?
TAC> Would this be more or less likely to have problems with pin track infection?
Speculatively the incidence shouldn't be more likely. Though only practice will show.
Date: Wed, 10 Dec 2003 08:26:00 -0600
From: J. Tracy Watson, M.D.
Subject: Re: Ilizarov wires through screws?
I THOUGHT that this was a good idea about 6-7 years ago....and the utilized this concept of placing an Ilizarov wire through a cannulated screw in the fixation of complex SH VI plateau fracture....the stability is incredible...in fact we tested this out in the lab some of this data was published in OCNA article on Circular fixation of complex plateau fxs......HOWEVER.....out of two patients that I did this on clincally.....the first developed a severe pin tract infection...that required screw removal....and the second tracked down the wire to the screw...then up into the joint......one of only two septic joints I have had utililzing small wire fixation techniques on tibal plateaus......I think that the normal ability of pins sites to seal off and become relatively infection resistant is inhibited....one of the causes of pin tract infection is the accumulation of fliud at the pin bone interface....which normally egressed out thru the external pin /skin interface....with this construct this fluid now has a clear tract directly into the center of bone...and then possibly up thru the fx. into the joint.
Clasper JC, Cannon LB, Stapley SA, Taylor VM, Watkins PE. Fluid accumulation and the rapid spread of bacteria in the pathogenesis of external fixator pin track infection. Injury. 2001 Jun;32(5):377-81.
I abandoned the technique because the rate and risk of severe complications was present...in my case 100%.
JTW
Date: Wed, 10 Dec 2003 09:48:44 -0500
From: Kevin Pugh
Subject: Re: Ilizarov wires through screws?
Agree. There is also some toggle depending on the diameter of the screw...as the wire does not interact with the bone. Tough shot as well.
kp