Date: Wed, 24 Nov 2004 20:35:17 -0500

Subject: Femur fx - proximal screw failure

From: Charles M. Blitzer

X-ray is of proximal locking screw failure in a 50 male with diaphyseal nonunion.

I would appreciate suggestions for dealing with this. With the screw broken near the lateral edge it concerns me that trying to pull the nail out might fx the neck. I would like to do an exchange nailing for the diaphyseal nonunion.

Thanks for your thoughts.

Charles Blitzer

Date: Wed, 24 Nov 2004 19:51:16 -0600

From: Adam J. Starr, M.D.

Hi.

I don't think it would fracture the neck. What I'd do is back out the lateral portion of the screw, and then use a tamp and knock the distal portion of the screw (the broken medial tip of it) in a little bit, so the nail will clear easily when you back the nail out. Then I'd run an overmill down the screw track and see if I could capture the broken piece.

Or, you could just leave the broken part in there.

Good luck. And remember the old Parkland saying: Nobody looks good taking out hardware.

Happy Thanksgiving.

Adam Starr
Dallas

Date: Wed, 24 Nov 2004 22:38:52 -0600

From: Obremskey, William T

I agree with Adam Starr on how to remove screw.

I would also suggest in addition to the exchange IMN to open the fracture and bone graft. Carolinas Medical Center report of only 50 % union with just IMN exchange supports this unless the fx appears to truly be a hypertrophic nonunion.

Bill Obremskey

Date: Thu, 25 Nov 2004 16:34:15 +0500

From: Alexander Chelnokov

Hello Charles,

CMB> near the lateral edge it concerns me that trying to pull the nail out might fx the neck. I would like to do an exchange nailing for the diaphyseal ..

I agree with Adam - push the distal part of the screw medially just to unlock the nail. We have a tool for removal such parts of cortical screws through the window in the lateral cortex, maybe such an instrument is available for another thread. Though I wouldn't spend extra efforts to remove the broken part if it doesn't prevent new nail insertion.

Best regards,

Alexander N. Chelnokov
Ural Scientific Research Institute of Traumatology and Orthopaedics
7, Bankovsky str. Ekaterinburg 620014 Russia

Date: Sun, 28 Nov 2004 23:14:45 EST

From: Tadabq

Charlie

I have seen distal broken screws prevent nail extraction and fracture the femoral shaft on attempted removal. I was consulted intra-operatively on a case where the nail was partly removed and radiographs demonstrated the residual medial part of a broken distal screw had cut through about 10 inches of medial cortex (incredible and I wouldn't have thought it possible if I hadn't seen it with my own eyes). I use that radiograph to illustrate the point that implant removal is fraught with trouble. Such a response in your case could produce a femoral neck fracture orother severe injury to the femoral head and neck. Therefore I suggest caution. I have taken the connecting rod from the C series Hoffman external fixator (4 mm diameter stainless steel)and beveled the ends (one flat and the other with a slight hollow or concavity). I use that to tap the residual medial part of the broken screw immediately after removal of the lateral portion and the screw. In the distal femur the medial piece can be extracted by another incision or left. In the only case of proximal femur broken screw I left the screw in the medial thigh and is has stayed there for at least 3 years as thenonunion united. I keep the connecting rod for sterilization on cases with broken screws. For smaller screws (3.5 mm tibial) use the mini Hoffman connecting rod. You could use anything that works as a tamp but it's best if it is strong, straight, cylindrical, slightly less diameter than the screw,reasonable working lengthand has a flat end. Sorry. If you try to extract the rod and it only comes a little then you lose the alignment of the lateral part of the screw to the nail and it makes it difficult to drive the medial part of the screw out. The threads may get caught on the inside of the nail. I have never had any luck with trying to overdrill the screw through the nail. I don't think there is room. You can over-drill the tip from the medial side if it is sticking out of the cortexand you do a medial exposure. I've done that distally but never proximally.

Bonne chance.

TD