Date: Sun, 15 Feb 2004 21:34:31 +0000

From: Jeff Richmond

Subject: Pelvic Nonunion following bone graft harvest

These are films from a 60 year old woman referred to me by a spine surgeon. She underwent PSH in August for stenosis and fell in October, fracturing through her bone graft site. She needs to go to the OR for revision fusion due to pseudos and loose hardware, and has severe posterior pelvic pain related to this nonunion. Her symptoms have not improved, and she states that the pelvis hurts at least as much as her legs did prior to her spinal decompression. Her gait is terrible. She has no pain or tenderness in the front.

This seems like a crescent fracture nonunion. I have seen 2 fractures through posterior crest harvest sites and both "united" or became assymptomatic non-operatively, but this lady is not getting better. Re-instrumenting her spine down to the iliac wing doesn't seem like it would do any good as there is no bone or continuity. SI fixation is not possible. Would lagging/plating the posterior crest with (bottled) bone graft be doomed to fail?

Any opinions/assistance would be much appreciated.

Jeff Richmond, MD
North Shore University Hospital
Manhasset, New York

Date: Mon, 16 Feb 2004 10:02:14 -0800

From: Chip Routt

You can easily do an anterior iliac exposure and fix the crest component and also plate across the SI joint to secure the pelvic brim portion.

You should strongly consider lumbopelvic fixation to treat both issues...just make sure that the pelvic portion of the fixation construct extends to the AIIS area.

M.L. Chip Routt, Jr.,M.D.
Professor-Orthopedic Surgery
Harborview Medical Center
Seattle, WA 98104-2499

Date: Mon, 16 Feb 2004 15:40:58 -0500

From: James Carr

I agree with Chip. As I see it, a major issue is osteoporosis. Also, I am not sure the front is healed, even though not painful. The plate on the inner pelvic rim could go from the sacrum, and perhaps catch some of the crescent fracture posteriorly. The iliopectineal line region will have some semblance of good bone. Augment with biologics. I thought I saw a pelvic locking plate (?). I did not pay much attention at the time, but this may be one legit use.

James B. Carr, MD
Palmetto Health Orthopedics

From: Thomas A Schildhauer

Sent: Monday, February 16, 2004 2:22 PM

Lumbopelvic fixation using long transiliac pedicle screws between the PSIS and the AIIS (up to 140 mm) would allow you to stabilize the ilium fracture and would give you a sufficient stabilization/anchor for your lumbar spinal instrumentation. The long screws directly transfer the spinal loads to the anterior part of the ilium above the acetabulum and thereby bridging the fracture site. The unloading of the fracture site would allow earlier, at least partial weight bearing, and hopefully healing since micromotion at that fracture site is minimized with decreased loads at the fracture itself.

I have used that technique successfully in sacroiliac/posterior pelvic ring instabilities due to SIJ/posterior ilium destruction in comminuted fractures, infection and in tumors. If I couldn't combine the lumbopelvic fixation with an SI-screw - like in your patient -, then I used two transiliac screws and at least two pedicle screws in L4 and/or L5 and/or S1. The transiliac screws however should not be inserted with prominent heads over the PSIS, but rather inserted slightly medially to the PSIS to avoid soft tissue problems.

Priv.Doz.Dr.T.A.Schildhauer
Chirurgische Klinik
BG-Kliniken Bergmannsheil
Ruhr-Universitt Bochum
Germany

Date: Mon, 16 Feb 2004 17:18:15 -0800

From: Carlo Bellabarba

I have seen a couple of similar cases, and one of the many problems is that, probably for reasons related to why they sustained a pathologic fx and nonunion through the bone graft harvest site in the first place, these patients also invariably fail to heal their spinal arthrodesis. This brings up several questions regarding whether the spine pseudarthrosis should be addressed primarily, vs the pelvic mal/non-union, vs. both.

If you are willing to accept the pelvic deformity, which is not that bad in the case presented but in general may become a matter of considerable debate that depends on several patient-related factors, then the decision is easier. One could address both the spinal and pelvic pseudarthroses by extending the posterior fixation into the pelvis, with or without percutaneous iliosacral screw fixation as described in Dr. Schildhauer's previous posting. The iliac screws can therefore serve the dual role of stabilizing/unloading the pelvic pseudarthrosis while supplying solid caudal fixation to the revision spine instrumentation.

If, however, the pelvic deformity is more severe and requires sequential anterior and posterior approaches to appropriately release/osteotomize, reduce and stabilize the pelvis, attempts to try and solve both the pelvic and spine problems simultaneously are probably unwarranted. That decision depends partly on the physiologic status of the patient, however. and would most likely require staged procedures on separate days. A decison would therefore have to be made, based on various patient related factors, regarding which of the two problems should be addressed first.

On a related note, the last such patient that I treated presented to me with an L4-S1 infected pseudarthrosis and long-standing (>18 mos) pelvic nonunion with severe malalignment , but less pelvic pain than the one presented to the list. I elected to address her spine issues first, for obvious reasons, and have unfortunately met with limited success so far. The pelvic pseudarthosis is therefore still on hold. If and when the pelvic surgery takes place, it will likely require a three-stage ant-post-ant procedure, but her deformity is considerably worse than in the case presented.

Issues to consider in the patinent in question are therefore:

1) Why did this patient develop a pelvic fracture through their bone graft site, and why did she not heal either her pelvis or her spine? The cause of fracture is primarily poor bone quality (they almost always occur in older women). Possible causes of her pseudarthrosis that need to be ruled out other than the usual medical comorbidity- vs poor bone quality-associated risks are infection, poor nutritional status, heavy smoking, or just plain bad luck, among others. The lucency around her spinal fixation is somewhat worrisome for infection. I would do a serological workup for infection and obtain intraoperative gm stain/cultures at the time of revision

2) The patient has only moderate pelvic deformity, and may therefore be amenable to combining revision spine surgery with lumbopelvic fixation across her pseudarthrosis, with or without iliosacral screw fixation. As mentioned above this would provide the added benefit of providing excellent caudal fixation for the spinal construct, something which would otherwise be a challenge given her osteopenia and current status of her S1 pedicle screws. (ie I would also intrument the unfractured hemipelvis).

3)Allograft may or may not help - I would probably try it, though. She may be a candidate for OP-1.

4) This is not an easy problem to fix. Good Luck.

Carlo Bellabarba, MD
Orthopaedic Trauma
Spine Trauma and Reconstruction
UW/Harborview Medical Center
Seattle, WA

Date: Tue, 17 Feb 2004 01:42:57 +0000

From: Jeff Richmond

Thanks for all of the input so far. I may not have posted the appropriate CT cuts, but I don't see how SI screws will help as they would be going through the region of the bone graft harvest and therefore wouldn't be getting any purchase in the fractured hemipelvis.

I am going to present all of this to the spine surgeon and get his opinion, as well as a serological w/u for infection.

Thanks for the assistance.

Jeff Richmond, MD
North Shore University Hospital
Manhasset, New York

Date: Mon, 16 Feb 2004 18:17:17 -0800

From: Chip Routt

Routine iliosacral screws would not be effective for your patient, at least according to the images that you sent.

M.L. Chip Routt, Jr.,M.D.
Professor-Orthopedic Surgery
Harborview Medical Center
Seattle, WA 98104-2499

Date: Mon, 16 Feb 2004 19:56:11 -0800

From: Carlo Bellabarba

Jeff,

Just to clarify -- lumbopelvic fixation = long "pedicle" screws placed in iliac wings from PSIS to AIIS connected to more cephalad lumbosacral pedicle screws. In general terms, we often combine these with iliosacral screws to get multiplanar fixation. If iliosacral screws can't be safely placed or would be ineffective (as is admittedly the case here), then, I would try and stack a couple of iliac screws side by side. A good reference for this technique is: Schildhauer T et al, J Spinal Disord Tech. 2002 Jun;15(3):199-205.

Carlo Bellabarba, MD
Orthopaedic Trauma
Spine Trauma and Reconstruction
UW/Harborview Medical Center
Seattle, WA