Gastrocnemius Flaps for Coverage of Antibiotic Spacers for Internal Total Knee Replacement

Gastrocnemius flaps are commonly used flaps to cover the proximal aspect of the tibia or distal knee joint. Gastroc flaps have become one of my favorite flaps over the years as they can be readily harvested through an extension of a previous incision.

Care should be taken when harvesting the flap to preserve the saphenous vein as this can significantly help the edema that is often present in the re-operative lower extremity. Furthermore, appropriate preservation is helpful as it may be used as a back-up for venous outflow if free tissue transfer is needed.

I find that one of the most helpful maneuvers in the gastroc flap is to remove the fascia from the under surface of the muscle. This allows for the exposure of a raw surface to adhere to the bone or antibiotic spacer. The raw muscle allows greater contact and exposure of surface area to the underlying object.

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Gastroc Flaps for Coverage of Total Knee Replacements

 



 

 

Knee replacement surgeries are common procedures. Total knee replacement infections can occur between 0.3% and 12.4% for primary TKR and between 1-15% for revision TKR. When total knee infections occur, a multi-stage reimplantation is emerging as the gold standard for the treatment of infected total knees.



The first stage includes the removal of the infected prosthesis and the stabilization of soft tissues. Common flaps that are used around the knee joint include the gastrocnemius muscle flap and occasionally it is appropriate to jump directly to free microvascular tissue transfer.

At the time that the prosthesis is removed, a temporary antibiotic spacer is placed that elutes an antibiotic. Usually the antibiotic is tobramycin and often vancomycin is placed in the cement.

Typically, clinical examinations are followed and laboratory results such as CRP, ESR, and white blood cell count are monitored. Usually after a period of 6-12 weeks when all soft tissues have stabilized and are no longer hostile and an antibiotic course has been completed, then the antibiotic spacer is removed and permanent knee prosthesis is placed.



 

 



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Free Latisimus Muscle Anastomosis to Popliteal Artery

Large radiation wounds or defects of the posterior aspect of the leg require vascularized tissue to heal. The free latisimus flaps offer long vascular pedicles, a significant amount of muscle for coverage.

When no vessels are available in the lower extremity, free tissue transfer can be performed by anastamosing the latisimus muscle flap to the popliteal artery and a saphenous vein branch for arterial outflow.

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Repair of Urethral Fistulas with Free Buccal Mucosal Graft and Gracillis Muscle Flap

Urethral fistulas can be a result of trauma or infection and can be a challenge to close for both the physician and patient. Closure of the wound requires urinary diversion and well vascularized tissue to close the wound. Of paramount importance when repairing urethral fistulas, is that there should be no downstream obstruction, so that a decreased resistance allows closure.

 

When there is a stricture of the urethra, a free buccal mucosal graft from the mouth can be used to substitute for the urinary epithelium. Buttressing of the buccal mucosal graft requires well vascularized tissue. The gracilis muscle is an excellent choice, for bringing in well vascularized tissue into the perineum. Hyperbaric oxygen can be a useful adjunct to faciliate wound closure.

 



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Rectus Muscle Free Flaps for Coverage of Radiated Skull Bone and Cranioplasty Plates

Superficial Temporal Artery and Vein for Recipient Vessels.

The superficial temporal vessels are excellent recipient vessels when planning for free microsurgical tissue transfer of muscle flaps to the skull. The superficial temporal vessels can be easily palpated crossing the zygomatic arch just superior to the root of the ear. The superficial temporal vessels are frequently quite toruous as one dissects proximally. It is perfectly fine to leave the vessel in it's native configuration and anastamose distal to the corkscrew of the artery.



Typically the rectus abdominis muscle provides adequate bulk and surface area to cover plates that are placed on the skull in cranioplasties. The bulk of the muslce helps to obiterate any dead space that may be present after bony debridement.

Once adequte flow is confirmed in the muscle through adequate bleeding and appropriate doppler flow, a skin graft is usually harvested from the lower extremity and then placed on top of the muscle.

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Journal of Craniofacial Surgery Publication

Correction of Massive Hydrocephalus and Brain Wound in Holoprosencephaly

Dickinson, Brian P.; Spoon, Daniel B.; Cordray, Tracy L.; Lazareff, Jorge; Wasson, Kristy; Bradley, James P.

Journal of Craniofacial Surgery. 17(4):707-713, July 2006.

Coverage of Massive Brain and Skull Defects with Latismus Dorsi Free Flaps

Latissimus Free Flaps for Massive Brain and Craniofacial Skull Wounds

Large defects of the craniofacial skull that are created from cancers, trauma, radiation, or other causes, often require microvascular free tissue transfer to close the wounds. On the vertex of the skull, there is limited tissue to close even small wounds and the amount of tissue is often decreased even more significantly if the tissue mobility is affected by radiation. The transfer of free muscle allows the operative surgeon to 1) cover any open wounds and 2) obliterate dead space which can often cause recurrent or recalcitrant infections.

Massive wounds of the brain and skull require complete debridement of all devitalized, radiated, necrotic, and osteomyelitic bone to allow the wound to heal properly. After all of the necrotic and devitalized material has been debrided, then the microsurgeon can bring well vascularized tissue to the area to help heal the wound.

The latissimus dorsi offers the most optimal muscle to be transferred to the scalp as it has a broad surface area to cover the entire scalp. The size match of the thoracodorsal vessels also coincide well with the size match of the superfical temporal artery and vein to allow an appropriate size match. It is important for the operative surgeon to be prepared to harvest either the greater saphenous vein or the lesser saphenous vein in the lower extremity in case the superficial temporal vein is inadequate. In this case the venous anastamosis needs to be jumped to the external jugular vein in the neck. This should be marked out pre-operatively and no central venous lines placed on that side of the neck pre-operatively.

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