Outcomes Of Traditional And Modified Gastrocnemius Myocutaneous Flaps For Treatment Of Osteomyelitis In The Tibia And Lower Femur

Objective: To summarize the clinical experience in treatment of the tibial,patellar and lower femoral osteomyelitis with soft tissue defects using traditional and modified(extended anterior,lower and / or posterior boundaries)medial and lateral gastrocnemius myocutaneous flaps,and compare survival rates of the flaps and outcomes of these osteomyelitis between modified and traditional medial(lateral)gastrocnemius myocutaneous flaps.Methods: From January 2002 to January 2022,medial(98 cases)and lateral(44 cases)gastrocnemius myocutaneous flaps used to treat the aforementioned osteomyelitis were analyzed retrospectively.The borders of the modified medial gastrocnemius myocutaneous flap are as follows.The anterior boundary exceeds the medial edge of the tibia and can reach the anterior crest of the tibia at most.The lower boundary is 2 ～ 4cm(<5cm)above the medial malleolus,and the posterior boundary is 3cm beyond the posterior midline.The modified lateral gastrocnemius myocutaneous flaps have the borders as follows.The anterior boundary exceeds the anterior edge of the fibula,maximally reaching the anterior crest of the tibia;The lower boundary is 3 ～ 9cm(< 10cm)above the lateral malleolus.The pretibial skin is equally divided into nine zones,the first to the ninth zone from top to bottom.compare survival rates of the flaps and outcomes of these osteomyelitis between modified and traditional medial(lateral)gastrocnemius myocutaneous flaps.Improved ASAMI function evaluation system was used to evaluate the function of affected limbs.Results: The patients were followed up for 1 ～ 196 months.The survival rates of traditional and modified medial gastrocnemius myocutaneous flaps were 88.1%(59/67)and 87.1%(27/31),respectively;recurrence rates of the osteomyelitis treated with these flaps were 10.4%(7/67)and 6.5%(2/31),respectively.The survival rates of traditional and modified lateral gastrocnemius myocutaneous flaps were 100%(15/15)and 89.7%(23/26),respectively;recurrence rates of the osteomyelitis treated with the two kinds of flaps were 13.3%(2/15)and 6.8%(2/26),respectively.All the differences mentioned above were not statistically significant(P > 0.05).The anterior boundaries of the modified medial and lateral gastrocnemius myocutaneous flaps averagely extended by 2.2cm(1.0 ～ 4.0cm)and 4.4cm(1.0 ～ 7.5cm),respectively;the survival rates of the two types of flaps were 90.9%(20/22)and 88.9%(24/27),respectively.The survival rates of the modified medial and lateral gastrocnemius myocutaneous flaps for reconstructing the pretibial soft tissue defects in lower 1 / 3 of the leg(the seventh and / or eighth zones)were 9/10 and 3/3,respectively.Three cases modified medial gastrocnemius myocutaneous flaps with extended posterior boundaries survived completely.Conclusion: Traditional and modified myocutaneous flaps of both medial and lateral gastrocnemii are good methods for treating the tibial,patellar and lower femoral osteomyelitis with soft tissue defects.The modified medial and lateral gastrocnemius myocutaneous flaps are feasible and reliable,and can reconstruct wider,larger and farther(lower thrid leg)defects of soft tissues.