Applied Anatomic Study Of Medial Sural Artery Perforating Branch And Clinical Study Of The Modified Medial Sural Artery Island Flap

Objective: The anatomic characteristics of the medial sural artery and the main perforating branch were studied and analysed through the dissection on the cadaveric specimens. In order to provide anatomic basis for clinical applications of the modified medial sural artery island flap with pedicle of the medial sural artery, which consist of perforating branch, so as to investigate the feasibility and clinical efficacy of the modified medial sural artery island flap in managing plate exposure combined with infection of postoperative proximal tibial fracture.Methods: 1.Eight fresh cadaver lower limbs from Chinese adult cadavers were injected with latex barium sulfate solution through femoral artery and were dissected, The date such as the number of perforators, the pedicle diameters,the external diameters, the pedicle lengths, the perforating point were measured and recorded, these data were analyzed by SPSS13.0 statistical software. and then the integument covering the lower leg was examined under X-ray to observe the location and distribution of the medial sural artery. 2. Between Janury 2013 and June 2015, the modified medial sural artery island flap were used to reconstruct proximal tibial osteomyelitis combined with bone exposure in 15 patients at our institute. There were nine man and six woman. aged from 24 to 58 years old(average 35.6 years), there were 10 cases in the left and 5 cases in the right. 10 cases suffered from traffic accidents, 3 cases from falling injury and 2 cases from mechanical injury. According to Gustilo fracture classification, the fracture of the type Ⅰ in 12 cases and of type Ⅱ in 3 cases. They were treated by reduction and internal fixation in one stage or multi-period stage in other hospital, the plate or bone exposure due to the soft tissue necrosis and infection, the exposure time from11 to 74 days(average 34d).According to the bacterial culture of secretion at the infection site, there were 10 cases suffered from Staphylococcus aureus, 2 cases from Pseudomonas, 2 cases from Staphylococcus epidermidis, one case from Acinetobacter baumannii. The flap size and shap design were based on the size of skin flap defect after debridement. the areas of flap sizes ranged from 3.6 cm×4.2 cm~5.3 cm×6.5 cm. The flap survival rate, complication,the function of knee and ankle joint, appearance of satisfaction were followed up.Results: 1. All of the 8 cadaver legs were found that there were 18 branches medial sural artery perforators, 1~3 perforators were found in each leg(2.3 branches on average),which 5 branches arise from the medial sural artery, the others arise from the lateral sural artery. The average external diameter of the perforator at the deep fascia was 0.87±0.25mm(0.6 mm~1.1 mm), and the average external diameter of pedicle was 1.82±0.47 mm(1.3 mm~2.3 mm). The length of the perforators was 3.2 cm~8.2 cm(on average 5.4cm), and the length of the branches pedicle was 6.5 cm~15.7 cm(on average 11.2cm),The perforating points of the medial sural perforators emergence were found in an area of7.6 cm~17.8 cm(on average 10.9 cm) from the popliteal crease, and 1.3 cm~4.2 cm(on average 2.8 cm) from the posterior midline. 2. Flaps survived in all patients cases. the muscle flaps in 14 cases healed in phaseⅠand those in 1 cases healed in phaseⅡ. the average hospital stay was 27.3 days, which from 12 to 50 days. The 15 patients had a minimum follow-up of six months(6~24 months), at the last follow-up, the donor site were healed well, the sensory function of the skin were hardly affected, the flap were characterized by soft texture, good color, and no ulceration happened. There was no infection recurrence, no bone nonunion or malunion, no stiffness of the joint occured in the last follow-up.. According to the modified ASAMI criteria for bone healing, 10 cases were excellent, 4 good, one moderate, zero poor.Conclusion: 1.The presence of the medial sural artery and perforating branch is consistent. It can obtain stabilize blood flow when the intramuscular perforator and the original artery were contained in the modified medial sural artery island flap were harvested, which is the anatomic basis for the modified medial sural artery island flap. 2.The advantages of the flap include its avoid plate removing, shorten the hospitalization time, reduce the economic burden of patients, low donor site morbidity, leaving an aesthetically good result, which makes it reliable alternative for treatment of plate exposure combined with infection of postoperative proximal tibial fracture at one stage.