METHOD FOR SURGICAL TREATMENT OF SHOULDER JOINT ARTHROSIS WITH INSTALLATION OF REVERSIBLE ENDOPROSTHESIS METAGLENE Russian patent published in 2024 - IPC A61B17/56 A61F2/40 

FIELD: medicine.

SUBSTANCE: invention relates to medicine, namely to traumatology, orthopaedics and neurosurgery, and can be used for surgical treatment of arthrosis of shoulder joint with installation of metaglene of reverse endoprosthesis. Anatomically correct axis of implantation of the virtual model of the glenoid component of the prosthesis – metaglene and the required length of its leg are determined on the virtual computer model of the shoulder joint. Method includes virtual implantation of model of metaglene in articular process of scapula with imitation of plastic augment involved in pathological process of articular process of scapula with verification of its correctness. Based on the computed tomography of the patient, an augment is made, as well as an individual guide from MED610 photopolymer for positioning a central pin in a deformed articular process of a scapula during a surgical intervention. Individual guide has a cylindrical shape with an inner surface facing the metaglene, repeating the shape of the outer surface of the metaglene. Individual guide is equipped with a central axial round hole to accommodate the guide pin for subsequent drilling of the hole in the articular process of the scapula with diameter of 6.8–7.2 mm for placement of a metaglene leg during its surgical implantation and three curved fixing hooks of temporary placement located along the front edge of the individual guide and fixing the individual guide and augment on the glenoid during the surgical intervention. With the patient’s supine position, perform a deltopectoral approach to the patient’s shoulder joint by incising the skin and subcutaneous fat with length of 14–16 cm to expose v.cephalica. Soft-tissue tenodesis of a long head of biceps is performed with sutures. Subscapularis muscle are taken with suture-holders, is cut off and mobilized, and the shoulder joint is inspected, the humeral head is dislocated into the incisional wound, cartilage remains are removed, an osteotomy of a shoulder head is performed at the level of an anatomical neck, and a glenoid with periarthrolysis of a shoulder joint is separated. Remnants of cartilage on glenoid are removed, lip of glenoid is excised. Individual guide is combined with the augment and temporarily fixed on the articular process using the bent fixing hooks of the individual guide. Guide pin is positioned in the central axial hole of the individual guide, along which a cannulated drill is used to form a canal with diameter of 6.8–7.2 mm and depth of 10 mm or 15 mm in the glenoid. Guide is separated from the augment, and a revision metaglene leg with a leg length of 10 mm or 15 mm is implanted into the canal formed in the glenoid. Metaglene is fixed through an augment to glenoid with two screws with blocking and with two screws without blocking. Glenosphere with diameter of 38 mm or 42 mm is fixed to the metaglene, the canal is successively formed by rimmers in the proximal part of the humerus of the patient, and the required size of the humeral component of the prosthesis is determined using test legs. Bone cement penetration limiter BioSTOP is inserted into the cavity of the medullary canal. Medullary canal of the humerus of the patient is filled with a bone cement with an antibacterial agent, and the prosthesis leg of the selected size is cemented. Polyethylene insert is implanted and the prosthesis is reduced. Range of motion and stability of the prosthesis are checked, and the rotators are transosseously reinserted to the patient's humerus. Joint is washed with an antiseptic solution, haemostasis, layer-by-layer wound closure, active drainage and fixation of the patient’s upper extremity in the abduction splint are performed. Augment and fixing screws are made of titanium alloy BT6.

EFFECT: method provides the possibility of creating a sufficiently pre-set volume of active and passive abduction and flexion of the shoulder in the shoulder joint of the patient, lateralization of scapular component in shoulder joint with increase of lever effect of deltoid muscle function, anatomical restoration of the shape and anatomical function of the shoulder joint structures due to the peculiarities of the reversible endoprosthesis metaglene installation.

1 cl, 3 ex