## 3 Technique Description
Surgical treatment always carries a risk of infection, wound healing problems, adhesions of sutures to the tendon, and iatrogenic nerve injury, i.e., a sural nerve [29]. Both open and percutaneous surgeries always entail the risk of damaging the nerves and causing wound-related complications [30]. However, the development of mini-invasive surgery on the Achilles tendon allows surgeons to reduce the wound complications rate, but various percutaneous techniques increase the risk of sural nerve entrapment (1.7-27%) [31]. On the one hand, high-resolution ultrasounds used intra-operatively in Achilles tendon suturing can minimize the risk of the a sural nerve injury during repair; on the other hand, it can improve the accuracy of needle penetration of the tendon's stump [32]. [PERSON] et al., in their study, examined 57 patients who underwent acute Achilles tendon ruptures with percutaneous sutures between 2005 and 2015. In the non-ultrasound-guided procedure group, three of fifteen patients had symptoms of sural nerve entrapment, whereas in the ultrasounds navigated group, none suffered from this. The authors revealed also that the real-time intra-operative ultrasound imaging of the sural nerve requires experience and proper skills. [PERSON] et al. combined ultrasound and percutaneous Achilles surgery in their study and also reported excellent results with no sural nerve complications [33]. [PERSON] et al. described the ultrasonographic visualization of the ruptured tendon for sural nerve visualization before endoscopic portal placement during endoscopic Achilles tendon repair [34]. It was designed to minimize the risk of sural nerve injury during Achilles repair, and the authors supported endoscopy during repair. The double-assisted surgery (both ultrasonographically and endoscopically guided) reduces the complication rates. Another important method is ultrasound-guided gastrocnemius recession as a mini-invasive technique in MSK surgery [34]. An isolated gastrocnemius contracture is thought to lead to numerous foot and ankle pathologic conditions, and as the authors mentioned, the resulting equinus deformity alters the foot biomechanics and increases forefoot pressure, aggravating or predisposing the patients to conditions such as Achilles tendinosis,  
Figure 5: (**a**) Organised hematoma (H) is seen in intraoperative sonography as hypoechoic heterogenic echo between the soleus (S) and gastrocnemius (G) muscles. (**b**) Fibrotic organised hematoma evolving into scar (H) was evacuated using arthroscopic shaver. The pathologic tissue was localised intraoperatively via sonography between the soleus (S) and gastrocnemius (G) muscles. flatfoot, lower back pain or strain, diabetic foot ulcer, knee hyperextension (genu recuratum), metataralsalgia, plantar fascitis, midfoot pain or arthritis, lateral foot pain, and nerve entrapment [35]. Gastrocnemius recession can be performed as a traditional open surgery or as an endoscopic, mini-invasive technique. The complications after open techniques have been described, such as poor cosmetic outcomes, neurovascular compromises, and wound complications. Endoscopic gastrocnemius recession is less invasive and has advantages over traditional procedures: a shorter operative time, fewer complications, and reduced morbidity rate [36]. [PERSON] et al. observed the complete release of the gastrocnemius tendon in all cases in the cadaveric study. No damage to the sural nerve or vessels occurred, and there was a minimal damage to the underlying muscle fibers. The authors observed that the degree of ankle dorsiflexion increased for every patient in the study, with a mean preoperative VAS score of 7, which improved to 0 postoperatively. The AOFAS Ankle-Hindfoot Score improved from a mean of 30 to 93 at 6 months with no major complications. Another important modality in MSK mini-invasive surgery is ultrasound application in carpal tunnel surgery [37]. Carpal tunnel syndrome is the most common peripheral entrapment neuropathies, occurring in approximately 3-5% of the general population.