ObjectiveTo compare the short-term effectiveness of femoral prosthesis with different neck-shaft angles for the reconstruction of proximal femoral anatomy after total hip arthroplasty (THA). MethodsBetween January 2012 and December 2013, 101 patients undergoing unilateral THA who accorded with selection criteria were selected for a retrospective study. The patients were divided into 2 groups:during THA, femoral prosthesis with 135° neck-shaft angle was used in 52 patients (group A) and femoral prosthesis with 127° neck-shaft angle was used in 49 patients (group B). There was no significant difference in gender, age, weight, body masss index, pathogeny, disease duration, preoperative neck-shaft angle, leg discrepancy, and preoperative Harris score between 2 groups (P>0.05). The postoperative Harris score was recorded to evaluate the effectiveness. And the femoral offset of the operated and contralateral sides, the change value of the femoral offset (xFO), the ratio of xFO to the offset of contralateral side (sdFO), the number of patients whose sdFO was more than 15% or less than -15% (outlier), the global offset, the height of femoral head rotation center, and leg discrepancy were measured at postoperation. ResultsOperative incision healed by first intension in 2 groups; no complication of infection, dislocation, or revision was found. All patients were followed up 12-32 months (mean, 23 months). The Harris score at last follow-up were significantly improved when compared with preoperative score in 2 groups (P＜0.05), but there was no signficant difference between 2 groups (t=1.267, P=0.832). The xFO and sdFO of group B were significantly larger than those of group A (P＜0.05); the number of outlier was 20 in group A and was 33 in group B, showing significant difference (P=0.005). The height of femoral head rotating center and global offset at 3 months after operation showed no signficant difference between 2 groups (P>0.05). And significant improvement in leg discrepancy was found at 3 months in 2 groups (P＜0.05), but there was no significant difference between 2 groups (t=0.403, P=0.689). ConclusionBoth of the two femoral prosthesis with different neck-shaft angles can restore the proximal femoral anatomy well and gain similar early effectiveness after THA. However, the Stryker Trident femoral prosthesis with 127° neck-shaft angle may have the tendency to enlarge the femoral offset.
ObjectiveTo explore the method and feasibility of digital internal fixation for proximal tibia fractures using standard parts database and three-dimensional (3D) printing technology. MethodsTen adult lower extremity specimens were selected to take continuously thin-layer scanning. After Dicom image was imported into the Mimics software, the model of Schatzker Ⅱ-VI types proximal tibia fracture was established, 2 cases each type. The virtual internal fixation was performed with plate and screw from standard parts database. The pilot hole of the navigation module design was printed by 3D printing technique. The plate and screw were inserted by the navigation module. X-ray film and CT were taken postoperatively to observe the position. Thirty patients with proximal tibia fracture underwent digital internal fixation using standard parts database and 3D printing technology (study group), and another 30 patients underwent traditional open reduction and internal fixation (control group). There was no significant difference in sex, age, side, causes, fracture classification, associated injury, and course of disease between 2 groups (P>0.05). The preparative time, incision length, fracture healing time, operation time, and intraoperative blood loss were recorded. Follow up of imaging evaluation, clinical efficacy was evaluated by MacNab criteria. ResultsThe navigation models were designed to fit the bony structure of proximal tibia and to guide implant insertion. The parameters of orientation, length, diameter, and angle were consistent with the preoperative plan. No statistically significant difference was found in the preparative times of pre-operation between 2 groups (t=1.393, P=0.169). The incision length, wound healing time, blood loss, operation time, and the cost of treatment in study group were significantly less than those in control group (P<0.05). All patients were followed up 12-16 months (mean, 13.5 months). The fracture healing time of study group was significantly shorter than that of control group (t=4.070, P=0.000). At 12 months postoperatively, there was no significant difference in the efficacy based on MacNab criteria between 2 groups (U=377.000, P=0.238). ConclusionDigital internal fixation for proximal tibia fractures using standard parts database and 3D printing technology has the advantages of short process, less blood loss, high safety and rapid fracture healing.
ObjectiveTo evaluate the effectiveness of high tibial osteotomy (HTO) assisted by three-dimensional (3-D) printing technology for correction of varus knee with osteoarthritis. MethodBetween January 2014 and June 2015, 16 patients (20 knees) with varus knee and osteoarthritis underwent HTO assisted by 3-D printing technology; a locking compression plate was used for internal fixation after HTO. There were 6 males and 10 females, aged 30-60 years (mean, 45.5 years). The disease duration was 1-10 years (mean, 6.2 years). The unilateral knee was involved in 12 cases and bilateral knees in 4 cases. According to Koshino's staging system, 3 knees were classified as stage I, 7 knees as stage Ⅱ, 8 knees as stage Ⅲ, and 2 knees as stage IV. Preoperative Hospital for Special Surgery (HSS) knee score was 63.8±2.2; the femorotibial angle was (184.8±2.9) °; and Insall-Salvati index was 1.03±0.13. ResultsAll the wounds healed primarily, and no complication of infection, osteofacial compartment syndrom, or deep vein thrombosis was observed. All patients were followed up 6-18 months (mean, 12.6 months). Personal paralysis was observed in 1 case (1 knee), and was cured after expectant treatment. Bone union time was 2.7-3.4 months (mean, 2.9 months). At 6 months after operation, the femorotibial angle was (173.8±2.0) °, showing significant difference when compared with preoperative one (t=11.70, P=0.00) ; Insall-Salvati index was 1.04±0.12, showing no significant difference when compared with preoperative one (t=-0.20, P=0.85) ; and HSS knee score was significantly increased to 88.9±3.1 (t=-25.44, P=0.00) . At last follow-up, the results were excellent in 13 knees, good in 6 knees, fair in 1 knee, and the excellent and good rate was 95%. Conclusions3-D printing cutting block can greatly improve the accuracy of HTO, avoid repeated X-ray and multiple osteotomy, shorten the operation time, and ensure better effectiveness for correction of varus knee with osteoarthritis.
Objective To explore the feasibility and the effectiveness of the accurate placement of lumbar pedicle screws using three-dimensional (3D) printing navigational templates in Quadrant minimally invasive system. Methods The L1-5 spines of 12 adult cadavers were scanned using CT. The 3D models of the lumbar spines were established. The screw trajectory was designed to pass through the central axis of the pedicle by using Mimics software. The navigational template was designed and 3D-printed according to the bony surface where the soft tissues could be removed. The placed screws were scanned using CT to create the 3D model again after operation. The 3D models of the designed trajectory and the placed screws were registered to evaluate the placed screws coincidence rate. Between November 2014 and November 2015, 31 patients with lumbar instability accepted surgery assisted with 3D-printing navigation module under Quadrant minimally invasive system. There were 14 males and 17 females, aged from 42 to 60 years, with an average of 45.2 years. The disease duration was 6-13 months (mean, 8.8 months). Single segment was involved in 15 cases, two segments in 13 cases, and three segments in 3 cases. Preoperative visual analogue scale (VAS) was 7.59±1.04; Oswestry disability index (ODI) was 76.21±5.82; and the Japanese Orthopaedic Association (JOA) score was 9.21±1.64. Results A total of 120 screws were placed in 12 cadavers specimens. The coincidence rate of placed screw was 100%. A total of 162 screws were implanted in 31 patients. The operation time was 65-147 minutes (mean, 102.23 minutes); the intraoperative blood loss was 50-116 mL (mean, 78.20 mL); and the intraoperative radiation exposure time was 8-54 seconds (mean, 42 seconds). At 3-7 days after operation, CT showed that the coincidence rate of the placed screws was 98.15% (159/162). At 4 weeks after operation, VAS, ODI, and JOA score were 2.24±0.80, 29.17±2.50, and 23.43±1.14 respectively, showing significant differences when compared with preoperative ones (t=14.842,P=0.006;t=36.927,P=0.002;t=–36.031,P=0.001). Thirty-one patients were followed up 8-24 months (mean, 18.7 months). All incision healed by first intention, and no complication occurred. During the follow-up, X-ray film and CT showed that pedicle screw was accurately placed without loosening or breakage, and with good fusion of intervertebral bone graft. Conclusion 3D-printing navigational templates in Quadrant minimally invasive system can help lumbar surgery gain minimal invasion, less radiation, and accurate placement.
Objective To evaluate the effectiveness of distal femoral osteotomy aided by three-dimensional (3D) printing cutting block for correction of vaglus knee with osteoarthritis. Methods Between January 2014 and January 2016, 12 patients (15 knees) with vaglus deformity and lateral osteoarhritis underwent medial closing wedge distal femoral osteotomy. There were 5 males and 7 females, aged 30-60 years (mean, 43.8 years). The mean disease duration was 6.6 years (range, 1–12 years). The unilateral knee was involved in 9 cases and bilateral knees in 3 cases. According to Koshino’s staging system, 1 knee was classified as stage I, 9 knees as stage II, and 5 knees as stage III. The X-ray films of bilateral lower extremities showed that the femorotibial angle (FTA) and anatomical lateral distal femoral angle (aLDFA) were (160.40±2.69)° and (64.20±2.11)° respectively. Mimics software was used to design and print the cutting block by 3D printing technique. During operation, the best location of distal femoral osteotomy was determined according to the cutting block. After osteotomy, internal fixation was performed using a steel plate and screws. Results All incisions healed primarily; no complication of infection or deep vein thrombosis was observed. All patients were followed up 6-18 month (mean, 12.2 months). At 6 months after operation, the hospital for special surgery (HSS) score for knee was significantly improved to 89.07±2.49 when compared with preoperative score (65.27±1.49,t=–28.31,P=0.00); the results were excellent in 10 knees, good in 4 knees, and fair in 1 knee with an excellent and good rate of 93.3%. The bony union time was 2.9-4.8 months (mean, 3.3 months). Bone delayed union occurred in 1 case (1 knee). The postoperative FTA and aLDFA were (174.00±1.41)° and (81.87±1.06)° respectively, showing significant differences when compared with preoperative ones (t=–18.26，P=0.00;t=–25.19,P=0.00). The percentage of medial tibial plateau in whole tibial plateau was 49.78%±0.59%, showing no significant difference when compared with intraoperative measurement (49.82%±0.77%,t=0.14,P=0.89). Conclusion 3D printing cutting block can greatly improve the accuracy of distal femoral osteotomy, and ensure better effectiveness for correction of vaglus knee with osteoarthritis.