The clinical application of Bone cutting guide in artificial knee arthroplasty

Abstract

Objective To investigate the application of the customized and personalized osteotomy guide plates by using 3D printing technology in artificial knee arthroplasty. Methods The patients who were treated with unilateral total knee arthroplasty in the First Affiliated Hospital of Shenzhen University from June 2011 to September 2015, were retrospectively analyzed, which included 11 males and 16 females, aged from 57 to 82 years, average 63.2 years. The pre-operation Hospital for Special Surgery(HSS) score of the knee joint was 40-56, average 49.7 points. All enrolled patients took X-ray examination of the two limbs full-length line, the anteroposterior and lateral of the knee and the patella axis to evaluate the joint degeneration and external deformity. Twenty-seven patients underwent a thin-layer CT scan of the knee, the three-dimensional reconstruction was carried out after the scan data were collected. The three-dimensional reconstruction of lower extremity was obtained to determine the osteotomy of the distal femur and posterior condyle, the proximal tibia and osteotomy angle by measuring femur extroversion and extorsion, tibial platform posterior slope angle. Finally, we printed 1∶1 femur and tibial osteotomy guiding plate by using the US Stratasys company ObjetEden260VS printer with resin printing material MED610.Then, the osteotomy plates were used for total knee arthroplasty. The operation time and intraoperative blood loss were observed. Patients were followed up regularly after surgery to observe the recovery of joint function, pain, incision infection and other complications. Twelve months after surgery, pain was assessed by VAS and knee range of motion, degree of deformity correction, stability and knee function were assessed by HSS. Results All 27 patients completed the operation successfully. The operation time was 40-80 min, averaged 55 min. Intraoperative blood loss was 150-250 mL, averaged 180 mL. Two patients incision healing was delayed with diabetes and 1 diabetes patient occured the incision infection but the incision healed with conservative treatment. Postoperative joint pain was significantly relieved in 4 cases, pain complete alleviate in 23 cases, joint extension and flexion activities were significantly improved, varus deformity, flexion contracture deformity and extension deformity were significantly corrected. Post-operative VAS score, knee range of motion, stability, and HSS score of knee joint function were (29.07±1.98)point, (16.81±1.55)point, (9.93±0.35)point and(89.41±3.23)point, respectively. Preoperative scores were (15.19±5.96)point, (12.52±2.06)point, (7.33±1.66)point and(49.70±4.40)point, respectively. The postoperative scores were all higher than those before the operation, and the differences were statistically significant(t=9.088, 6.186, 6.575, 27.050, all P values<0.01). Conclusions Using the 3D printing technology for customized and personalized osteotomy guiding plate has the advantages of accurate osteotomy, time saving and small trauma during the total knee replacement. It has important clinical application value, especially, for patients with severe osteoarthritis, joint deformity, rheumatoid arthritis and traumatic arthritis of the knee joint. Key words: Arthroplasty, replacement, knee; Bone cutting guide; 3D print