Date: Feb 2000 09:48:59 -0500
Subject: Femoral Neck Nonunion
From: Howard Routman
Here is an interesting case... 32 year old laborer s/p fall from 2 story window with femoral shaft fx treated with IM Rodding succesfully and a femoral neck fx treated with DHS and supplementary 7.3 cannulated screw fixation which went on to nonunion.
The nonunion was fixed with intertroch osteotomy
Now 7 months postop with impending failure of fixation (proximal migration of blade).
His pain, although improved from preop, is present and he is 50% WB on that extremity. What would be the preferred timing of the next intervention (if any) and what would you choose to do? thanks,
Howard Routman, DO, Chief Resident - PCOM Orthopedics
From: Steven Rabin
Sent: Monday, February 21, 2000 1:52 PM
here's my opinion for this case.
i think the timing for the next intervention needs to be now since the situation will be worse when the hardware fails completely which looks inevitable with the change of postion of the blade plate. When the plate fails, the patient will have more pain, more bleeding, and will have to be operated on urgently instead of electively. Also, the screws or blade can loosen and cause windshield wiper effects losing more bone and making eventual repeat fixation harder.
the options are repeat internal fixation with plate or rod device and my choice would depend on preoperative planning and templating. I don't think i would consider replacement in this young patient without giving repeat fixation at least one more try. Replacement might have to be a calcar replacing prosthesis with a long stem to avoid the stress risers from the screw holes and may not last long in a 30 year old. I don't see any signs of AVN on these xrays and i would only consider replacement at this point if there was collapse from AVN.
i would also have a high index of suspicion for infection. the first surgery probably failed because the femoral neck was fixed in varus which is not biomechanically advantatgeous obviously, and probably had poor bone contact with relatively poor fixation with the screws in the superior head. the fixation was probably not rigid. However the second procedure looks like a nice osteotomy with restoration of the biomechanics and at least stable fixation so i would be concerned that the failure this time was due to a subacute occult infection. Take cultures and even frozen sections for pathology just as you'd do with a loose hip replacement to be sure there is not infection. (even if there is infection, i would refix it to provide a stable environment for bone healing.)
i would plan on bone grafting at the time of the next surgery using real iliac crest autograft and might even consider an implanted electrical stimulator although i'm not really a strong supporter of electrical stimulation, but it probably wouldn't hurt as long as you did not do additional devitalization of soft tissues putting it in.
If templates show that an intramedullary device would fit with adequate fixation proximal to the device, it would have the advantage of allowing immediate weightbearing. i'd consider a gamma type nail or its equivalent but only after real good templating. the disadvantage of a nail is that there will already be some soft tissue stripping from removing the plate. the advantage would be that the nail can be placed in a more biomechanically advantageous spot. If i went with a plate, i would consider bending a cobra plate to fit because there are so many holes already from the blade and the previous DHS lag screw that i'd like to get a lot of screws into the proximal segment and the cobra plate would allow me to place them at all sorts of different angles looking for good bone. Have a strong assistant to bend the plate. (other plates like the femoral supracondylar buttress plate would not be strong enough.)
this is opinion anyhow. hope it helps. good luck.
steve rabin. loyola u. med center
Date: Mon, 21 Feb 2000 15:38:52 -0600
From: Gregory J Schmeling
Fig 7 is dramatically different from fig 9. It appears to me that a subcapital femoral neck fracture has occurred around the fixation. You may now have 4 major fragments (head, neck, peritroch, shaft). A hip fusion would most likely fail due to the avascular segments (head, neck). A hemi-arthroplasty or arthroplasty may be your only choice, but what a choice in a 32 year old laborer. Have the patient get voc rehab, change jobs, plan on sedentary life and take away his pain with arthroplasty after w/u for infection when it gets bad.
Gregory J Schmeling
Date: Tue, 22 Feb 2000 10:06:10 +0100
From: bruce meinhard
RE: The Impending Blade plate failure case following the IT Osteotomy
It seems the biology for this case is not active. Any metabolic source should be ruled out. The next thing to consider is whether the head is alive or not. MRI/bone scan or craig needle bviopsy should be helpful as well as a culture of the biopsy to rule out infection...\ESR and CRP also.
On occasion I have had a blade fail despite good biomechanics (probably due to lack of fracture site compression) and if the head is alive, and without infection, one should consider a Valgus (say 150 degree and antirotation screw with fresh iliac bone graft. Depending on one's philosophy, internal or external electric stim may be selected as an adjunct.
Another opinion for active biology would be a free fibula tied into the deep vessels. Best wishes and good luck.
Date: Tue, 22 Feb 2000 09:42:13 -0600
From: Steven Rabin
i agree that the biology needs to be changed since the mechanics look good with the osteotomy. Another option might be a quadratus femoris vascularized graft instead of the vascularized fibula.
Date: Tue, 22 Feb 2000 14:54:30 -0600
From: Anglen, Jeffrey
I think that re-fixation is unlikely to help, as I cannot easily identify any obvious deficiency in the present fixation. Electrical stimulation definitely works, although not in every case, it is worth a try. Not every avascular head is symptomatic. Having said that, I foresee an endoprosthesis - modular, unipolar.
Reference: Anglen JO, Intertrochanteric osteotomy for failed internal fixation of femoral neck fracture. Clin. Orthop. 341:175-182, 1997.
However, all the patients in my small series healed (even with avascular head), so I cannot say for sure what to do when they don't heal.
Date: Fri, 25 Feb 2000 15:04:45 -0500
From: Howard Routman
Thanks everyone for your input.
Initial operative cultures were negative and he has had no overt signs of infection postop. We are still considering our options, so any other ideas are welcome.
Date: Thu, 2 Mar 2000 16:04:12 -0600
From: Jeff Mast
The fourth radiograph of the intra-operative series tells the story of the amount of compression generated by the use of the implant.
Not any STATIC compression! In this intra-operative radiograph, a clamp is shown holding the plate against the bone in the proximal region of the plate- osteotomy interface. This is an open angled plate and compression must be obtained by "mismatch", I challenge you, assuming good bone, what is the theoretical limit of compression - tension "Newtonian effects" that can be obtained by mismatch fixation with an open angled plate and screws in this situation. I can come up with 4 different effects...all synergetic to the overall effect of compression of bone surfaces !
Please look at Dr. Burman's presentation of a case of femoral neck non-union from the Mast/Mayo OTA workshop on nonunions/malunions and check-out the action drawing of "mis-match".
By the way, when you understand this you will not use the screw in the first hole under the plate,
which in this case enters the region of the neck nonunion and can only have a negative effect on bone that would like to heal.
Finally from what you showed us it looks like somewhere we picked up a fracture of the posterior neck, and the head contour is not looking normal...other than that from these radiograms, my vote is that it is healed!