FK radius head modular prosthesis Surgical Technique

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2 1. Operation Indication : FK radius head modular prosthesis Surgical Technique Comminuted, non-reconstructable break of radius head, Manson III, IV. Contraction restricting pronation and supination movements due to a former fracture that caused deformity or particular missing of the radius head. Terrible triad: elbow luxation, comminuted fracture of radius head, fracture of processus coronoideus which caused instability. 2. Operation in tourniquet: (In case of adults it is 300 hgmm.) The patient has to lie on his back on a normal table. Put the limb on an arm table that is permeable by X-Ray beam. The limb has to be sterilized from the tourniquet cuffs until the fingertips then left free isolated. 3. Direction of the surgical incision: The incision starts along the line of epicondyle radial humerus, above the radius head and along it in a distance of 5 7 cm. Do not cut ventrally from the epicondyle, because the deep branch of the n. radial can be damaged! The best position to access the radius head is the fascia loculum that is located between the anconeus and extensor carpal. It is useful to cut the ligamentum anulare slightly aslant, to make it easier to sew it together during the reconstruction works. Picture 1 Before the Resection Hohmann lifters have to be placed around the radial neck. Be careful and avoid the rough movements in order to save the branches of the n.radialis profound that are located around the neck in the supinator canal. Resection has to be performed by oscillating saw and blade in perpendicular direction to the longitudinal axis of the radius (Picture 2) We determine the ideal height of the resection with trial prosthesis ( xx). Always choose the shortest size! (Picture 3) Picture 2 Picture 3 1

3 4. Preparation of the implant s location: The opening and rasping process of the intramedullary canal has to be made by the rasps series ( x) using them in rising size sequence until we get to the maximum size while taking into consideration the thickness of the bone (Picture 5-6). The form of the slant nook on the rasp matches the 10 degree axle position of the neck. Its square based pyramid shape increases the rotational stability. The nib of the rasp has to be pointed towards the stretched thumb during the rasping process (Picture 7). Control the elbow s stability, its adequate valgity, its free movement and the size of the implant by using the trial prosthesis. - The instrument No is for insertion of trial prosthesis (Picture 8). Picture 5 Picture 6 Picture 7 Picture 8 5. Choosing and assembling the implant: 1) Choose the head with the adequate length and size (measured) that is packed and sterilized together with polyethylene inlay (Picture 9). Picture 9 2) Choose the sterilized stem that is going to be placed into the bone hole. Its size must be the same as the one of the rasp used for the last. (Picture 10) Picture 10 3) Flip it together by using the special pincer ( ) (Picture 11). 2

4 Picture 11 There is a special instrument on the instrument tray that can be used to separate the two components ( ) (Picture 12). 6. Insertion of the assembled implant: Picture 12 Check whether the assembled modular biarticular prosthesis can rotate freely before the insertion. Keep the elbow in varization and semiflectal position and insert the prosthesis into the radius. Pay attention to the right direction of the stem angle (Picture 13-14)! Stave in the prosthesis with the tool that was produced especially for this purpose ( ) (Picture 15). Picture 13 Picture 14 3

5 Picture 15 Picture Functional test: The test has to be performed both in stretched and bended elbow as well. Control if the rotation is free or not! The head stays normally in its location, so exactly in the opposite position to the capitulum humerus. (Picture 17-20) Picture 17 Picture 18 Picture 19 Picture 20 4

6 8. Closing of the surgical incision: If it shows luxation tendency, control it after the lig.anulare suture. If it still shows dislocation tendency, the joint must be investigated as the reason could be either interpositum in the Humero-ulnar joint, or the break of the ulna! (Picture 21-22) Picture 21 Picture 22 Joint drainage with Ch Redon drain. Fascia and subcutaneously and after skin suture (Picture 23-24). Picture 23 Picture 24 The limb has to be fixed with a square form upper arm plaster only until the scar recovers or in case of close cooperation it doesn t have to be plastered at all. Long term fixation (maximum 3 weeks) may be needed in case of dislocation tendency, but it may cause restriction in the elbow movement. Redon must be removed after hours. 9. Aftercare: Exercise: Elbow stretching and bending until the pronatio and supinatio pain boundary with the help of gymnastics expert and with controlled active exercises. 10. X-Ray controls: 1. Intraoperational functional test with image enhancement. (Picture 25-28) Picture 25 Picture 26 5

7 Picture 27 Picture Post operational closing image. 3. Control before leaving the hospital. 4. Control in four weeks following the operation. 5. Control in four months following the operation. 6. Control in every 2 years. Besides of the normal recommended controls, radiological investigation is needed every time when the patient has complaints, or if there is a suspicion of prosthesis luxation or other complication occurs (unexpected movement restriction, inflection, pain that could be sign of the slack of prosthesis). 6

8 Instrument set Instrument tray Radius Head Rasp S Radius Head Rasp M Radius Head Rasp L Picker Hammer Radius Head Rasp XL Introducer Radius Head Implant Forceps Assembler Radius Head Extractor Forceps Radius Head Trial 21 S Radius Head Trial 21 M Radius Head Trial 21 L Radius Head Trial 24S Radius Head Trial 24M Radius Head Trial 24L Radius Head Trial 24 XL Radius Head Trial 24 XXL Radius Head Trial 21 XL