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Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_4 | Pages 16 - 16
1 Apr 2019
ACCURACY OF PATIENT-SPECIFIC INSTRUMENTS IN EIGHT TOTAL HIP ARTHROPLASTIES THROUGH DIRECT ANTERIOR APPROACH: CADAVER STUDY RESULTS
Zembsch A Dittrich S Dorsch S
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Aims

Accurate placement of acetabular and femoral stem components in total hip arthroplasty (THA) is an important factor in the success of the procedure. A variety of free hand or navigated techniques is reported. Survivorship and complications have been shown to be directly related to implant position during THA. The aim of this cadaver study was to assess the accuracy of the placement of the components in THA using patient specific instruments (PSI) in combination with a 3D planning software and the direct anterior approach.

Method

Patient specific instruments (PSI) were developed to guide the surgeon during THA that were 3D printed with their bone models following a 3D software planning protocol (LPH software V2.5.1, Onefit-Medical, Eos Imaging Company, Besancon, France). Acetabular guides: cup, offset and straight reamer handle and impactor, femoral- and chisel guides were used in each THA (Fig. 1). To define anatomic bone landmarks and to generate a 3D model of each hip joint CT scans were performed preoperatively. The planning of component position was done by one surgeon (AZ) preop. Surgery was performed by two experienced surgeons (AZ, SD) on cadaver specimen with 4 hips in two separate series. A total of 8 hip replacements were evaluated pre- and postoperatively using CT-scans of each hip joint to compare planned to achieved results. Mechanical simulations of the guides were carried out to verify that there were no conflicts between the different instruments. To meet the ISO standard 16061: 2015 the compatibility of the instruments with the guides has been checked. Parameters were evaluated in 3D pelvic and femoral planes: center cup position, inclination angle, anteversion angle, cutting height and plan orientation, anteversion angle, flexion/extension angle, varus/valgus angle, anatomical and functional leg length, offset. Acceptance criteria: postop. parameters evaluated must not have a deviation of more than 5 degrees, 2,5 mm according to preop. planning. For every THA the test protocol has been completely realized.

Orthopaedic Proceedings
Vol. 86-B, Issue SUPP_III | Pages 342 - 342
1 Mar 2004
O3064 BLOOD SALVAGE DURING PELVIC TRIPLE OSTEOTOMY UNDER ADRENALIN AUGMENTED HYPOTENSIVE EPIDURAL ANAESTHESIA
Dorn U Zembsch A Neumann D Dohnalek C Lanner J Raffl M
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Aims: Evaluation of the potential of blood salvage in osteotomy of the pelvis after T…NNIS, using a special anaesthetic technique (Adrenalin Augmented Hypotensive Epidural Anaesthesia, AAHEA). Methods: From 1997 to 2002 thirtynine patients had surgery. 25 patients (4 men, 21 women; average age 33 yrs) had AAHEA and 14 (3 men, 11 women; average age 32 yrs) had standard anaesthesia. Autologous blood donation, intra-operative and postoperative cell saving was evaluated. The haemoglobine proþle, evidence of haematoma and the time needed for the operation were noted. In both groups 2 patients had additional surgery with intertro-chanteric osteotomy. Results: In this series haemoglobine was statistically signiþcant higher with AAHEA (p< 0,05) after a period of 7–10 days, and lower total usage of blood donation (p< 0,05) was evident. Amount of blood, collected with the cell saver intraoperatively: In the group with AAHEA 179 ml (± 155) versus standard-anaesthesia 935 ml (± 749); autologous blood donation: AAHEA-group 64% versus standard-group 77%. Conclusions: AAHEA is able to lower perioperative blood loss in major orthopaedic bone and joint surgery. This method leads to a remarkable reduction of the intra-operative blood loss and perioperative need of blood donation, autologous and homologous, further to a minimized risk of associated complications and lower costs.