## 3 Technique Description
described the advantages of synovectomy performed under double visualisation (arthroscopy and ultrasound). Owing to this method, it was possible to more clearly to identify the hypertrophic  
Figure 1: (**a**) Calcium deposit in intraoperative sonography. The probe is in axial plane, showing deltoid muscle (D) superficially in relation to supraspinatus tendon (arrows). Acromion border is seen on the right (A). The calcium deposit (arrowheads) is evident in the centre of supraspinatus fibres. (**b**) Multiple calcium deposits (arrows) during arthroscopic removal, temporarily disseminated above the upper surface of supraspinatus tendon (arrowheads). The tendon is palpated under double visualisation using arthroscopic hook (H). synovium. Ultrasound assistance allowed them to resect the septum dividing the knee joint. In another case, this modality was used to navigate the resection of the excessive synovium from a Baker cyst [15]. [PERSON] et al. described the original technique of the localisation of menisco-capsular separation during knee arthroscopy [16]. According to their findings, ultrasounds could be helpful in both the diagnosis and treatment of this kind of meniscal lesions. Another indication of ultrasound augmentation in mini-invasive surgery is during tibia bone resection and near patellar tendon insertion due to deformation caused by Osgood-Schlatter disease [17] (Figure 2). [PERSON] et al. analysed the results 3-5 years after the double visualization (US/arthroscopic) shaving of the involved part of the patellar tendon in tendinopathy (Figure 3). They proved that there is a correlation between the low score of pain during activity, a high patient satisfaction rate, and poor local blood flow. In comparison with sclerosing injections, both the treatment methods rendered good and equal clinical results at the mean 46-month follow-up, but US/ColorDoppler-guided arthroscopic shaving revealed a significant decrease in the anteroposterior thickness of the proximal patellar tendon [18]. Ultrasound guidance was also found to be effective in establishing portals for hip arthroscopy. It was described by [PERSON] et al. (2009) as a method which allows surgeons to avoid the fluoroscopy [19]. [PERSON] et al. revealed that sonographic guidance can be  
Figure 3: (**a**) Intraoperative sonography of the patellar tendon (arrowheads) tendinopathy. The transducer is placed in sagittal plane parallel to the axis of the femur (F). Doppler modality allows the precise localisation of neovascularization pathologic tissue (arrows) of the patellar tendon near the inferior pole of the patella (P). (**b**) Arthroscopic shaving (motorised shaver; asterisk) of the neovascularization pathologic tissue (N) of the bottom part of the patellar tendon (T) near inferior pole of the patella (P). Figure 2: (**a**) Sonographic visualisation of the arthroscopic removal of the tibia (T) deformity (arrows) with the use of motorised shaver (asterisk) of tibia (T) bony deformation caused by Osgood–Schlatter disease. The resection is carried out distally to the insertion (I) of the patellar tendon (arrowheads). (**b**) Arthroscopic removal with motorised shaver (asterisk) of tibia (T) bony deformation after Osgood–Schlatter disease. The resection is carried out distally to the insertion (I) of the patellar tendon (P). used for both peripheral and central compartment procedures in hip arthroscopy in prone and lateral patient positions [20]. [PERSON] et al. showed the limitations of this technique. It should not be taken into consideration in patients with morbid obesity and in cases of extensive heterotopic ossification [21]. Moreover, [PERSON] et al., in their 3D models of FAI deformity, showed that ultrasound guidance can be used when confirming joint distraction and establishing portals for hip arthroscopy [22]. The mini-invasive, arthroscopic treatment of hallux rigidus can also be augmented using ultrasound assistance (Figure 4) [23].