Chir. plastica (Berl.) 3, 271-276 (1976) Chiru..rgia plastlca �9 by Springer-Verlag t976

External Fixation as an Adjunct to the Use of Flaps to the Lower Extremity

M. AllgSwer and S. Krupp

Allgemeinchirurgische Klinik und Klinik ft~r Plastische- und Wiederherstellungschirurgie des Departmentes ffir Chirurgie der Universit/it Basel, Abteilung Plastische Chirurgie, Kantonsspital, Spitalstrage 21, CH-4000 Basel, Schweiz

Summary. The need for distant flap repair in compound injuries of the lower extremities has decreased considerably thanks to extensive use of autol- ogous cancellous bone and split skin grafting. If, however, flap repair becomes necessary and free flap transfer is not appropriate, external fixation clamps anchoring the bones considerably improve the possibility of secure fixation of the donor to the recipient limb as illustrated in the following cases.

Introduction

Open wound treatment, combined with stable but minimal internal fixation and secondary closure of the skin defect with a free skin graft, has very much reduced the need for primary and secondary flap repair in compound fractures, especially in the lower extremity (AllgSwer, 1971; Allieu and Pous, 1972; Bur- well, 1971; Hanza et al., 1971; Lejour et al., 1973; Roy-Camille et al., 1974). This holds true even if clear-cut osteomyelitis is present. The primary concern in such cases is removal of dead bone and replacement with autologous cancellous bone which, if deposited on vascular bone, can be left open until invaded by granulation tissue (Burri, 1975). The granulation surface is easily covered by split thickness skin grafts.

However, there still remain cases which require treatment by means of pedicle flaps and thereby necessitate immobilisation of the extremity for several weeks. It is in these cases that we have found the use of external fixation clamps most useful for protecting the skin flaps.

Technique

The skin flap is prepared in the usual way as soon as it is ready for transfer. The leg to be covered is brought into opposition with the flap. Instead of using plaster of Paris, which is less reliable, the two limbs are fixed to each other, using metallic external fixation.

272 M. Allg6wer and S. Krupp

Fig. la. The 23 year old patient suffered a traumatic amputation of the right leg, complicated by extensive skin loss. Because the leg stump was very short it was decided to cover the raw surface with a flap to fit a leg prosthesis. A thoraco-abdominal flap, measuring l0 • 20 cm, was constructed 3 weeks after the accident. 17 days later the distal end of the flap was transferred to the right forearm serving as a carrier

Arm to Leg Flaps

In deal ing with a flap which is already well healed to the carrier arm, we use one S t e inmann p i n - p r e f e r a b l y t h r e a d e d - w h i c h transfixes the forearm bones as well as the t ibia (see Fig. 1).

Cross-leg Flaps

If one t ibia is to be fixed to the other one as in the use of a cross-leg flap, or if the t ibia of one side has to be opposed to the femur of the other (Figs. 2 and 3) both long bones are secured by means of two to three threaded nails (Schanz nails).

Insertion oi c Transfixing (Threaded) Steinrnann pins

The inser t ion of threaded as well as of unthreaded S te inmann pins is carried out in such a way that we first drill through both cortices of the diaphysis a hole which is slightly smaller than the diameter of the S te inmann or Schanz pin. For a nail measur ing 4 m m in diameter we drill a hole of 3.6 m m and for a nail of 5 m m we open the cortex to 4.5 ram. This gives a very solid

Fig. lb . After a further 25 days, the proximal end of the flap was divided, and the flap was brought down to the stump of the right leg and sutured in place. The arm and leg involved were immobilised by a Steinmann pin secured by external fixation. The flap end was divided at the hand 3 weeks later, and the fixation was removed. Both sides of the leg stump were covered with split thickness grafts after 6 days following the flap division

Fig. lc . Final result of the right leg stump: stable skin conditions, with good fit to the prosthesis

274 M. Allg6wer and S. Krupp

Fig. 2a. This 24 year old patient suffered traumatic loss of the right Achilles tenon. 16 days after the accident a proximally based flap, measuring 12 x 17 cm, was mobilised on the medial side of the left thigh

Fig. 2b. After a delay of 11 days, the flap was transferred to the right leg, the two extremities being immobilised with external f ixation The flap was divided at its origin 14 days later, and the fixation was removed

hold of the nail in the cortex without causing heat damage, which may result if the nail is introduced into the bone without predrilling.

Once both long bones are transfixed by 3 to 4 threaded nails, they can be secured to each other by means of metal rods. To this effect we make use of the ASIF external fixation apparatus or the Hoffmann apparatus (Figs. 2 and 3).

This fixation offers various advantages: - stability and thus avoidance of traction on the flap, - easy access to all wounds and pressure points - balanced suspension of the fixed limbs so that active motion of the limb

is possible without jeopardizing the flap.

Fig. 2c. Result 5 mon ths after subsequent reconstruction of the Achilles tendon. Full function of the lower extremity has been restored, the patient being again able to play soccer

Fig. 3a. An unstable scar on a t raumatic foot s tump

Fig. 3b. A medially based cross-leg flap of 4 x 4 cm was raised on the right leg and immediately transferred to the foot stump, the two legs being immobilised with external fixation

Fig. 3e. Final result: stable scar on the foot s tump

276 M. Allg6wer and S. Krupp

References

Allg6wer, M: Soft tissue problems and the risk of infection in osteosynthesis. Langenbecks Arch. Chir. 329, 1128-1136 (1971)

Allieu, Y., Pous, J.G.: Quelle place reste-t-il ~ la chirurgie plastique et reconstructrice dans le traitement des fractures ouvertes de jambe? Ann. Chir. plast. 17, 212 217 (1972)

Burri, C. : Post-traumatic osteomyelitis. Bern-Stuttgart-Wien: Hans Huber 1975 Burwell, H.N.: Plate fixation of tibial shaft fractures. A survey of 181 injuries. J. Bone Jt Surg.

53-B, 258-271 (1971) Hanza, K.N., Dunkerby, G.E., Murray, C.M.M.: Fractures of the tibia. A report of fifty patients

treated by intramedullary nailing. J. Bone Jt Surg. 52-B, 696-700 (1971) Lejour, M., Burny, F., Panda, F., E1Bana, S.: Probl6mes cutan6s dans les fractures ouvertes du

tibia. Acta chir. belg. 72, 473484 (1973) Roy-Camille, R., Guillamon, J.C., Saillant, G., Sagner, P., Leli6vre, J.F., Reignier, B.: Treatment

of osteitis by excision and graft at open operations by Papineaus method. Chirurgie (Paris) 100, 48~487 (1974)

Received May 15, 1975