Proposal of a Modied Comprehensive Technique to Avoid Local Scarring and Adhesion Formation for Isolated Gastrocnemius Recession: a Comparison Study.

Background Poor cosmesis is one of the complications following surgical gastrocnemius recession by Strayer procedure. Our present study reported a modied comprehensive technique avoiding skin adhesion in releasing gastrocnemius contracture. A comparison cohort was conducted with inclusion cases via comprehensive modied technique and conventional Strayer procedure.


Conclusions
Gastrocnemius recession with modi ed comprehensive technique can completely release the gastrocnemius aponeurosis and achieve satisfactory recovery of ankle dorsi exion angle, especially effectively avoid postoperative local scar adhesion with a superior cosmetic appearance.
Due to the tethering of the wound skin and underlying fascia, postoperative problematic scarring and adhesion formation with hypertrophic or keloid scar could cause cosmetically unsatisfactory calf and evidently affect the surgical satisfaction of gastrocnemius recession, especially among young females (16).
To the best of our knowledge, no literatures has been reported to address the cosmetic and satisfactory concern. Our present study initially proposed a novel modi ed comprehensive technique, by utilizing preoperative color Doppler ultrasound to accurately mark the modi ed incision, operating gastrocnemius recession during plantar exion and then dorsi exion as to address the cosmetic complications of Strayer procedure. The outcomes of current comprehensive technique were measured and analyzed, and compared with that of a conventional Strayer procedure group.

Methods
From July 2017 to December 2019, 72 patients (84 feet) from our medical center were consecutively included in this retrospective cohort study, including 4 males (4 feet) and 68 females (80 feet), of which 56 patients (68 feet) were managed with gastrocnemius recession procedure for hallux valgus, 13 patients (13 feet) for atfoot and 3 patients (3 feet) for metatarsophalangeal joint replacement. And 38 cases(42feet)were managed with conventional Strayer procedure while 34 cases 42feet were treated with modi ed comprehensive technique ( Table 1). The most commonly used criterion to indicate an isolated gastrocnemius contracture is that > 10• of dorsi exion with the knee extended, which improves past neutral with knee exion (8). The angles of plantar exion and dorsi exion are indicated by positive and negative values, respectively.

Procedures of modi ed comprehensive technique
Preoperatively, at plantar exion position, color Doppler ultrasound was utilized to detected the musculotendinous junction of the well-placed affected foot, and the musculotendinous junction was marked on the skin. The center of the modi ed incision should be located approximately 3cm to the vertical line of the medial border of the tibia.
Intraoperatively, place the affected foot at extreme plantar exion, a 3-cm vertical incision was made through skin at the previously marked modi ed incision. The subcutaneous tissue and super cial fascia were bluntly dissected down. The gastrocnemius musculotendinous junction was cut off along the borders of medial and lateral heads of gastrocnemius, respectively. Then the ankle was forcefully held in dorsi exion prolonging the gastrocnemius musculotendinous junction to reach a satisfying dorsi exion angle. Thus, the avulsion was located distally to the skin and soft tissue incision to effectively avoid direct contact of avulsion and incision to reduce adhesion formation. Then fat and subcutaneous tissue were sutured by absorbable thread conventionally.
Postoperatively, the affected leg was immobilized in a plaster while the ankle was kept at neutral dorsi exion for 2-3 weeks. The patients were encouraged to perform Achilles tendon and gastrocnemiusstretching exercises and ankle motion exercises during intermittent removal of plaster to further prevent scarring and adhesion formation.
The principle of modi ed comprehensive technique to prevent postoperative scar adhesion The color Doppler ultrasound was utilized to detected the musculotendinous junction and the musculotendinous junction was marked on the skin at extremely plantar exion position ( Fig. 1, location A), then the musculotendinous junction was marked again during extremely dorsi exion (Fig. 2, location B).
According to the distance between A and B, posterior medial edge of the tibia can be palpated, and the longitudinal or small arc incision was performed at the vertical line about 3cm from the posterior medial edge. The incision can be extended regrading the intersection of incision and line A as the center but avoiding any overlapping of incision and line B. With ankle plantar exion, the gastrocnemius musculotendinous junction was exposed and cut off sharply. With extreme dorsi exion, the lower edge of the gastrocnemius muscle slid to B (Fig. 2), and the musculotendinous junction was prolonged and extended to the distal end (C in Fig. 2). Thus, there was no direct contact between the incision D and extension area C, effectively preventing postoperative scar adhesions. Noteworthily, line E (Fig. 1) is the position of sural nerve, and it should be protected during the surgery thus exposure was not recommended.
The diagnostic criteria of scarring and adhesion formation: skin and soft tissue on operative incision scar moved with dorsi exion and plantar exion of the ankle joint, affecting the cosmetic appearance or patients complained about local stiffness and discomfort.

Statistical analysis
The Statistical Package for the Social Sciences (version 19.0; SPSS, Inc, an IBM Company, Chicago, IL) was used for the statistical analysis of data. The maximum passive dorsi exion angles of the ankle joint preoperatively and postoperatively within the group and between the groups were expressed in mean ± standard deviation (x ± s) and analyzed by the paired t test. Postoperative complication (scarring and adhesion formation) between the groups was compared using χ 2 test. A P value of less than 0.05 was de ned to be statistically signi cant.

Results
The mean follow-up was 13.6 months (12 to 18 months). All of them had obvious improvement in the maximum passive dorsi exion angle of the ankle joint with knee extension. The mean ankle dorsi exion signi cantly improved from 14.5º±2.5º degrees preoperatively to -18.7º±3.2º degrees in comprehensive modi ed procedure group (Modi ed group) postoperatively (P < 0.05), while dorsi exion improved from 15.2º±3.0º to -19.1º±3.9º in conventional Strayer procedure group (Conventional group) (P < 0.05) ( Table  2).   Utilizing the modi ed technique, preferable results were achieved except for limited local scar adhesion rate of 2.4%, possibly due to the overlap of the longer and lower incision with the avulsion of gastrocnemius release. Meanwhile one patient showed the symptom of gastrocnemius injury in both experimental and control group, which possibly due to the limited incision and excessive traction, and the patients recovered from the de cit within one month with neurotrophic medication. Generally, the ankle dorsi exion angles (with knee extension) were restored to -18.7º±3.2º from the preoperative 14.5º±2.5º (P < 0.01), which was consistent with the previous literature 20 on the lengthening of gastrocnemius aponeurosis and improvement of ankle dorsi exion angle. Thus, the present technique was proved to be reliable and effective. It is noteworthy that the novel modi ed comprehensive technique can effectively prevent the postoperative scar adhesion as well as lengthen the gastrocnemius muscle.

Intraoperative patient posture
All the patients in our present study were suffering from foot pathology with various etiologies, and most of them were positioned supinely during the operation. Whereas the prone position was recommended for a clear exposure and convenient operation for surgical gastrocnemius recession. And the change of the position during the operation resulted in additional steps and prolonged intraoperative time. To the best of our knowledge, supine position with the operating table inclining to the affected side for about 30 degrees is better for operation. Meanwhile, extreme ankle plantar exion and slight knee exion is recommended to be maintained by assistant for better surgical exposure.

Incision technique
According to the mark of the musculotendinous junction by ultrasonography preoperatively, the intraoperative incision was made as proximal as possible, and then was extended to distal junction area appropriately after the blunt exposure of gastrocnemius layer by layer to ensure that the distal end of the super cial skin incision was slightly proximal to the junction area (as indicated by the arrow in Fig. 3). If the incision was extended too far, there will increase the risk of the contact of the skin incision and the release area of gastrocnemius aponeurosis. In general, 3cm of vertical straight incision was enough; while for patients with high BMI, the incision could be extended to the proximal end, or a small arc incision can be made with vertex orientating the lateral side. After completely transection of gastrocnemius musculotendinous junction, the ankle joint was placed in extremely dorsi exion to mobilize the avulsion of the junction. The super cial surface of the avulsion and the distance between the proximal end of loose part and the skin incision can be seen through the surgical eld when the recession was completed (as indicated by the arrow in Fig. 4). Intraoperatively, the gastrocnemius fascia was intact within the incision and the muscle was not exposed.  Preoperatively, color doppler ultrasound was utilized to detected the musculotendinous junction, and morphological and anatomical structures were marked on the skin: (A) The mark of gastrocnemius musculotendinous junction when ankle joint in extremely plantar exion; (B) the mark of gastrocnemius musculotendinous junction when ankle joint in extremely dorsi exion; (C) the mark of the junction avulsion area; (D) the mark of the surgical incision; (E) the mark of the sural nerve.

Figure 2
When ankle joint in extremely dorsi exion: (B) the mark of gastrocnemius musculotendinous junction; (C) the white line showed the fallen deep avulsion of the gastrocnemius musculotendinous junction.

Figure 3
Intraoperative image of the Gastrocnemius Recession. The distance between distal end of the skin incision and the gastrocnemius musculotendinous junction. The intraoperative incision was made as proximal as possible, and then was extended to distal junction area appropriately after the blunt exposure of gastrocnemius layer by layer to ensure that the distal end of the super cial skin incision was slightly proximal to the junction area (red line).

Figure 4
In plantar exion, the incision of skin soft tissue and loose part. The enlarged image showed the gastrocnemius musculotendinous junction (red arrow). The super cial surface of the avulsion and the distance between the proximal end of loose part and the skin incision can be seen through the surgical eld when the recession was completed.