gms | German Medical Science

Open fracture, infection or tumorigenesis may cause soft tissue defects. Microsurgical reconstruction of soft tissue is needed in cases when bone, cartilage, tendon, nerves or large vessels are exposed. In particular, covering of large and complex soft tissue at the distal third of the leg and ankle joint is often performed using fasciocutaneous or myocutaneous flaps. The goal of the tissue reconstruction is a good functional outcome and patients’ satisfaction.

In 1906, Ignio Tansini first described the myocutaneous latissimus dorsi (MLD) flap, which was rediscovered by Neven Olivari in 1976 [1]. In 1984, Ruyao Song described the fasciocutaneous anterolateral thigh (ALT) flap, which has gained increasing importance for covering soft tissue defects in recent years [2].

In the past, the benefits and possible drawbacks of various types of flaps have been discussed. Fu-chan Wei and Yildirim reported that the fasciocutaneous ALT flap is a good alternative in terms of conventional myocutaneous tissue transfer [3], [4]. In a comparative study, Yazar et al. investigated myocutaneous and fasciocutaneous flaps. The authors demonstrated that the ALT flap is a valuable solution for defect coverage of less three-dimensional distal third and ankle traumatic open tibial fracture [5]. Advantages of the MLD flap include its potential in covering higher three-dimensional injuries and the good applicability in contaminated wounds [6]. The ALT is a demanding flap with vascular variety but provides the possible conversion to a tensor fascia lata flap or anteromedial thigh flap [7], [8]. Possible drawbacks of the MLD flap may be its appearance owing to the muscle fraction and the high flap volume at the distal lower leg and ankle, while a fasciocutaneous ALT flap involves less volume and thereby better cosmetic results [5].

The purpose of the present study was to evaluate patients’ satisfaction as well as the functional outcome following microsurgical fasciocutaneous and myocutaneous tissue transfers using standardized evaluations and questionnaires. The results of this study may contribute to surgeons’ decisions in selecting a suitable donor flap for microsurgical soft tissue reconstruction.

In the follow-up period from 2001 to 2005, 22 microsurgical anterolateral thigh flaps (ALT group) and 14 latissimus dorsi flaps (MLD group) were transferred for covering post-traumatic and chronic wound defects on the lower leg, ankle joint and midfoot. In addition, 3 patients were treated in case of tumorigenesis in the ALT group. The data acquisition was performed 2005 in the Hannover Medical School, Department for Plastic, Hand and Reconstructive Surgery. The time of investigation was set to at least 6 months after surgery in both groups. On average, the examination was carried out after 21.5 months. The following parameters were evaluated based on retrospective archive case files and prospective examination: isokinetic analysis (Biodex System III), circumference measurement, flap and scar size, complication rate, quality of life and mental health (SF-36), functional outcome (Foot and Ankle Outcome Score, FOAS), hospital stay, and duration of surgery, as well as age and gender.

In order to demonstrate the physical state of health of the patient, we performed an isokinetic resistance measurement. For this purpose, we used the Biodex System III in its capacity as a mechanical and electronic dynamometer.

For each patient, the individual range of motion was defined and the exercise data of 5 cycles at 60°, 120° and 180° were evaluated. After each cycle, a 30-second pause was included to prevent muscle fatigue.

The maximum peak of torque was compared for the operated and the non-operated lower extremity in both groups. The maximum torque was calculated by the computer based on the highest measured value of five repetitions. The maximum force was formed from the maximum torque after five repetitions at an angular velocity of 60°/sec. A high angular velocity (180°/s) leads to a low resistance of the dynamometer, which allowed measurements of the strength endurance.

In the investigation of the maximum torque, the difference is shown as the percentage deficit between the surgically treated and not surgically treated extremities. A negative value indicates that the values were higher for the operated extremities than for the non-operated extremities.

In both groups, we excluded patients with arthrodeses from isokinetic exercises (ALT group n=3, MLD group n=4). In the ALT group, we also excluded one patient (n=1) with a nervus ischiadicus lesion, which existed before reconstruction, and one patient (n=1) who did not participate in the follow-up examination.

A comparative circumference measurement (in cm) of the covered and uninjured extremity in the ALT group and the MLD group was performed in a standardised manner 15 cm below the knee, at the narrowest part of the lower leg, ankle joint and midfoot. In addition, the difference (in cm) between the covered and uninjured extremities was calculated and compared between groups.

We arranged a clinical patient examination based on a self-designed investigation form, which included a measurement length by width (in cm) of the donor and recipient area to represent the flap size and the extent of the scar of the covered extremity in both groups.

Both groups were analysed for postoperative complications, including e.g. haematoma, seroma, flap necrosis, and flap failure.

To assess the quality of life, the self-reported SF-36 questionnaire, which is independent of the current state of health and age, was used. It is based on 8 subscales with 2 to 10 items. By adding the different subscales, a physical and mental summary scale can be calculated. The physical summary scale consisted of the subscales “physical function”, ”physical role of function” such as “general health perception” and “pain”. The mental summary scale is formed by the subscales “social functioning”, “emotional role of function”, “psychological well-being”, and “vitality”.

In addition, an independent item represents the health modification.

The analysis of the data was done using the test’s analytical methods. The items were coded and added in a specific weighting. Thus, a comparison between the different scales and health modification is group-specific possible.

In addition, there was a group-specific analysis of the data compared to the normal population.

The Foot and Ankle Outcome Score questionnaire was used to evaluate the patient satisfaction and functional outcome. It is based on the Knee Injury and Osteoarthritis Outcome Score (KOOS) and consists of 42 items with the following five subscales: pain, other symptoms, activities of daily living, sport and recreation function, and foot- and ankle-related quality of life. In contrast to the SF-36 questionnaire, these questions are up to date to the events of the previous week. The total score from each subscale was added up, multiplied by 100 and divided by the maximum score for each subscale. The result was finally subtracted from 100. 100 points indicate no symptoms while 0 points indicate extreme symptoms.

By statistical analysis, hospital stay and duration of surgery were comparatively investigated.

In addition, a statistical analysis of age and gender in the ALT group and the MLD group was carried out.

The statistical data analysis was done using SPSS Statistic Version 15 (SPSS Inc,.Chicago, IL). In addition to the standard descriptive statistics, we used for parametric methods the t-test, the Kolmogorov-Smirnov test and the Shapiro-Wilk test. For the non-parametric methods were used ANOVA, the Mann-Whitney test, the Wilcoxon W-test and the U-test. A p-value equal to or less than 0.05 was considered to be significant. In this work, the methodological advice of the Department of Clinical Epidemiology and Applied Biometrics of the Hannover Medical School and Medistat GmbH Kiel was obtained.

Maximum peak torque was compared by isokinetic resistance measurements in the operated and non-operated extremity in the ALT group and the MLD group. The maximum peak torque is generated by the computer registered highest measured value of 5 repetitions, which was determined for the operated and the non-operated extremity.

For the maximum peak torque of the operated extremity of the ALT group and the MLD group, the difference in dorsiflexion was highly significant at an angular velocity at 60°/s (mean ALT group 17.5±7.9 Nm, mean MLD group 18.5±16.3 Nm, p<0.013) and 180°/s (mean ALT group 8.17±5.6 Nm, mean MLD group 13.36±9.4 Nm, p<0.008) in favour of the MLD group.

With regard to the review of the percentage deficits between the surgically treated and non-surgically treated extremities between both groups, a significance (p=0.027) for the dorsiflexion in the MLD group is shown at the angular velocity of 180°/s.

However, by the examination of the percentage deficits for the dorsi- and plantarflexion at an angular velocity of 60°/s and 120°/s, as well as for the plantarflexion at an angular velocity of 180°/s, no significant differences were found. Furthermore, there were no significant differences between the non-operated extremities of the ALT and MLD groups.

The circumference measurement of the lower leg, ankle joint and midfoot was compared between the transplanted and uninjured side of the ALT and MLD groups. For the circumference measurement of the distal lower leg in patients with transplanted defects at the ankle joint, there was a significant difference (p<0.013) between the ALT group (25.0±3.39 cm) and the MLD group (30.36±2.14 cm). Even when considering the difference at the distal lower leg between the covered and uninjured extremities in both groups, a highly significant difference (5.58 cm, p<0.001) could be demonstrated for defects at the ankle joint with a larger circumference in the MLD group (8.13 cm) in comparison to the ALT group (2.55 cm). At the measurements 15 cm below the knee and at the midfoot, no differences between the transplanted and uninjured side were found (Figure 1 [Fig. 1]).

The flap size in the MLD group was significantly larger than in the ALT group (251.63±21.28 cm² vs. 148.77±6.58 cm², respectively; p<0.01).

The size of the scar at the donor site was significantly larger in the MLD group than in the ALT group (93.40±22.65 cm² vs. 40.61±4.93 cm², respectively; p<0.01).

Two flap haematomas were each recorded in the ALT group and the MLD group. Seroma at the donor site was registered only in the MLD group (n=2). Major complications, including superficial necrosis of the flap, occurred in both groups (ALT group n=3, MLD group n=5). The remaining defects were secondary covered successfully by skin transplantation. Complete flap failure was recorded only in the ALT group (n=2). The defects were then successfully covered with a free MLD flap. They were thus classified in the MLD group.

The quality of life was assessed using the SF-36 questionnaire based on eight subscales (Figure 2 [Fig. 2]). In the analysis of the individual subscales, there was no difference between the ALT group and the MLD group. Thus, the ALT and MLD groups behave similarly in relation to physically demanding activities, e.g. physical work, self-care, walking and climbing stairs, and also in terms of the degree and influence of pain. The subscale “health modification” showed no differences between the ALT group and MLD group, which reflects an assessment of the current state of health of the patients compared to the previous year. Even considering the individual physical and mental summary scales, no significant differences (p>0.05) were found between the ALT group and the MLD group (Figure 3 [Fig. 3]). Comparing the patients by groups with the normal population there were significant differences in all items of the physical summary scale except the subscale “general health perception” (p<0.05). There was no significant difference of the mental summary scale apart from the subscales “emotional role of function” and “social functioning” (p<0.05).

To determine the current patient satisfaction based on the week prior to the examination, the FAOS was used. It is a self-reported questionnaire that is composed of five subscales (pain, other symptoms, activities of daily living, sport and recreation function, and foot- and ankle-related quality of life). For the subscale “symptoms”, which increases with, for example, swelling or crunching friction of the transplanted extremity, there was a trend towards fewer problems in the MLD group (mean ALT group 54.2, MLD group 63.5; p=0.058). With regard to the analysis of “pain” or even in “activities of daily life” no differences between the ALT and MLD groups were found. Also there was no difference in the “quality of life” by the FAOS between the ALT group and the MLD group.

The mean value for hospital stay for the ALT group was 29.82 days (range 14–74 days) and for the MLD group 33.57 days (range 13–67 days).

The average operating time in the ALT group was 382.76 minutes (6.38 hours) and in the MLD group 390.77 min (6.51 hours).

The average age of the 36 patients during the time of reconstruction was 42.0 years (range 15–72 years) in the ALT group and 55.5 years (range 18–77 years) in the MLD group.

15 patients (68.18%) in the ALT group were male and 7 patients (31.81%) were female. In the MLD group, 10 patients (71.42%) were male and 4 patients (28.57%) were female.

Many results of the present study are consistent with previous investigations that compared myocutaneous and fasciocutaneous flaps. Overall we detected no significant differences in the quality of life and functional outcome when comparing microsurgical fasciocutaneous (ALT) and myocutaneous (MLD) tissue transfers to defects in the lower extremity. For defect coverage of high-grade soft tissue defects of the lower extremities, free flap transfers have often been used in the past [9]. Because of its reliable anatomy and the potential for coverage of large defects among other advantages, the MLD flap has been used standardly for the last years [10]. Recently, also the ALT flap has shown good potential for low extremity reconstruction in different studies [5], [10], [11]. However, comparative studies evaluating the patients’ satisfaction and functional outcome following microsurgical tissue transfer are rare.

In a comparative study, Hertel et al. investigated functional outcome and total costs for patients who received reconstructive coverage compared with amputated patients [12]. Functional outcome of reconstructed extremities was significantly better. Additionally the permanent social disintegration is much higher in the amputation group, and so a reconstruction should always be preferred if possible. Rodriguez et al. compared in a retrospective study the quality of life and functional outcomes of patients with reconstructive surgery at the lower extremity with either ALT flap or a muscle flap (M. rectus abdominis, M. gracilis) [7]. They did not find any differences in the quality of life or functional outcomes between the flaps either in the short musculoskeletal assessment form or in the physical tasks given by a physical therapist.

To the best of our knowledge, there are no other studies that compare the musculocutaneous and fasciocutaneous flaps at the lower extremities concerning their postoperative force and muscular endurance using the Biodex System. In the analysis of the maximum force and muscular endurance, there were significantly higher values for dorsiflexion at an angular velocity of 60°/s for the MLD group compared with the ALT group. Furthermore, for the percentage deficits of dorsiflexion at 180°, there was a significant difference in favour of the MLD group. All other measured movements showed no significant differences between the groups. In the present study, the treated patients judged the function of the operated extremities as equal in both groups. The significant differences in the results between the flaps are physiologically difficult to explain. The higher flap size of MLD and the partial subsequent better agility of the transplanted extremity might eventually be responsible for the detected effect. The limited group size of the present study may also have played a role. Therefore, we think that further comparative studies are necessary to test the validity of the measurement for the research question posed and to evaluate the different results for the flaps.

In a similar study to our investigations, there were no significant differences in the duration of hospital stay or the duration of the surgery [11]. In the present study, there was also no difference between the ALT and the MLD group.

In a previous study, Demirtas et al. found that the two flaps (myocutaneous vs. fasciocutaneous) differ regarding the scarring and tissue trauma to the donor and recipient area, and thus the appearance, due to their volume [11]. For measurements of scars in the donor area and the recipient area, there were significantly larger scars at the donor side and at the recipient side of the MLD flap compared to the ALT flap. This leads to a different aesthetic result of the flaps. However, the MLD flap allows reconstruction of larger defects due to its larger flap size. Furthermore, previous studies reported an increased morbidity of the donor area following free muscle transfer [5], [11]. Based on the data of this study, we can confirm a trend towards more postoperative complications at the donor area following myocutaneous latissimus dorsi transfer compared to anterolateral thigh flap. However, the low number of complications occurring here allowed no statistical comparison.

Yazar et al. showed a cosmetically better result of the fasciocutaneous flap compared with the myocutaneous flap in the area of the ankle and foot due to the lower volume of the ALT flap [5]. Consecutive interventions for volume reduction were correspondingly less common in fasciocutaneous flaps. In our study, also two interventions for volume reduction were performed, both in the MLD group. As was shown at the ankle joint of the transplanted extremity in the present study, a significant increase in the size of the circumference was measured when using the MLD flap.

In a previous study, the overall complications of fasciocutaneous and myocutaneous flaps were similar [11]. In our study, the postoperative complications of the two flaps did not differ either.

Regarding quality of life and mental status following fasciocutaneous versus myocutaneous flaps by the SF-36 questionnaire, there were no significant differences between the methods of tissue transfer. Comparing both groups with the normal population there were significant differences with better results for the normal population in parts of the SF-36. Here, the differences were found mainly in the physical summary scale, such as the subscales “physical function”, “pain”, and “physical role of function”, which could be explained with the surgical interventions at the lower extremities.

In the functional comparison of the ALT and MLD flaps by the FAOS questionnaire, there were also no significant differences between the applied grafts during everyday life. For example, subjective pain in everyday life was judged equal in both groups. In addition, time of return to work did not differ between the groups.

Overall, with respect to the quality of life and functional outcome, the two grafts were equivalent in our investigation. This corresponds to the trend of increasing use of fasciocutaneous flaps in recent years, since tissue trauma and donor area complications seem to be higher in myocutaneous flaps [11].

Despite the above observations, the selection of the appropriate graft should be aligned individually to the patient. Here, in addition to the criteria examined in the present study, other important parameters should be considered. The MLD flap allows the possibility of covering larger defects, whereas the ALT flap can be used more variably since, depending on need, additional muscle tissue can be lifted. Therefore, the MLD flap is used more often in proximal lower leg defects whereas the ALT flap is more reliable in ankle and foot defects [7], [13]. The overall complications of both methods are similar to judge whereby the ALT flap is operationally demanding and is therefore only a good alternative in the hands of experienced surgeons [11]. In previous studies it was shown that a soft tissue covering with muscle tissue has a positive effect when used in complex wounds, including fractures, and so there may be advantages of the myocutaneous graft [5], [14]. However, in minor complex wounds and fractures at the ankle and foot an advantage of ALT flaps was seen [5]. Some of the above criteria are already considered by the authors in clinical practice in indication for surgeries.

Due to the small sample size of the study and the heterogeneous patient population with inclusion of 3 cancer patients in the ALT group, the results of the study are not fully applicable to all flap transfers of the lower extremities.

Nevertheless, with respect to the appropriate individual selection of a graft for lower leg defects, the present study provides important additional information regarding the differences and similarities of both grafts. The significant difference between the flaps in the Biodex measurements remains unclear. Therefore, in our opinion, further studies are necessary to evaluate the ideal indications for fasciocutaneous and myocutaneous flaps.

The authors declare that they have no competing interests.