ObjectiveTo study the difference of femoral condylar twist angle (CTA) measurement in three dimensional (3-D) reconstruction digital models of human knee joint based on the two dimensional (2-D) images of MRI and CT so as to provide a reference for selecting the best method of CTA measurement in preoperative design for the femoral prosthesis rotational position. MethodsThe CTA of 10 human cadaveric knee joint was measured in 3-D digital models based on MRI (group A), in 3-D digital models based on CT (group B), in the cadaveric knee joint with cartilage (group C), and in the cadaveric knee joint without cartilage (group D), respectively. The statistical analysis of the differences was made among the measurements of the CTA. ResultsThe CTA values measured in 3-D digital models were (6.43±0.53)° in group A and (3.31±1.07)° in group B, showing significant difference (t=10.235, P=0.000). The CTA values measured in the cadaveric knee joint were (5.21±1.28)° in group C and (3.33±1.12)° in group D, showing significant difference (t=5.770, P=0.000). There was significant difference in the CTA values between group B and group C (t=5.779, P=0.000), but no significant difference was found between group A and group C (t=3.219, P=0.110). ConclusionThe CTA values measured in the 3-D digital models based on MRI are closer to the actual values measured in the knee joint with cartilage, and benefit for preoperative plan.
Objective To investigate the effect of applying a tourniquet on perioperative blood loss and short-term effectiveness in primary total knee arthroplasty (TKA). Methods A total of 94 patients (94 knees) with osteoarthritis underwent primary TKA between September 2010 and December 2011, whose data met the inclusion criteria and were retrospectively analyzed. A tourniquet was used in 51 cases (group A), no tourniquet in 43 cases (group B). There was no significant difference in gender, age, affected side, body mass index, preoperative hemoglobin (Hb) level, range of motion (ROM), visual analogue scale (VAS), Hospital for Special Surgery (HSS) score, Western Ontario and McMaster University Osteoarthritis Index (WOMAC) between 2 groups (P gt; 0.05). The data were compared between 2 groups, including hematocrit (Hct), Hb, hidden blood loss, dominant blood loss, theoretical total blood loss, the operation time, hospitalization days, increasing rate of circumference length above 10 cm of the knee, VAS score, ROM, HSS score, and WOMAC score. Results Four cases (7.84%) of group A and 1 case (2.33%) of group B received blood transfusions, showing no significant difference (χ2=1.410, P=0.235). There was no significant difference in the Hb and Hct between 2 groups at 2 days after operation (P gt; 0.05). The dominant blood loss of group A was significantly less than that of group B (P lt; 0.05), while the hidden blood loss of group A was significantly more than that of group B (P lt; 0.05), but there was no significant difference in theoretical total blood loss between 2 groups (t=0.662, P=0.510). The operation time, hospitalization days, and VAS score at 3 days showed no significant difference between 2 groups (P gt; 0.05). The wound healed by first intention after operation without related complication. At 3 days after operation, the increasing rate of circumference length above 10 cm of the knee in group A was significantly higher than that of group B (t=9.435, P=0.000), but no significant difference at 7 days (t=0.462, P=0.645). At 3 and 5 days after operation, the ROM values in group B were significantly larger than those of group A (P lt; 0.05), but no significant difference at 7 days (t= — 1.279, P=0.204). The patients were all followed up 12-18 months (mean, 14.3 months). There was no significant difference in the HSS score between 2 groups at 1 year after operation (t=0.952, P=0.344), but significant difference was found in the WOMAC score between 2 groups (t= — 2.488, P=0.015). The X-ray films showed that the prosthesis was in good position, without loosening, subsidence, or osteolysis. Conclusion Application of a tourniquet in TKA increases hidden blood loss, and there is no obvious advantage in reducing transfusion rate compared with the non-tourniquet group, so it is recommended to reduce the time and pressure of the tourniquet for patients with high-risk of thrombosis.
Objective To compare the effectiveness of the traditional center of tibial plateau as the entry point and digital technology in the design of intramedullary tibial nail point positioning method in total knee arthroplasty (TKA). Methods Between October 2011 and October 2012, 60 cases undergoing unilateral TKA and meeting the selection criteria were randomly divided into 2 groups: in group A (30 cases), the tibial plateau center as the entry point of tibial intramedullary positioning was used; in group B (30 cases), Mimics 10.01 software to simulate the guide rod point of tibial intramedullary positioning was used. There was no significant difference in gender, age, etiology, disease duration, sides, and preoperative knee range of motion, Hospital for Special Surgery (HSS) score, and Western Ontario and McMaster University Osteoarthritis Index (WOMAC) between 2 groups (P gt; 0.05). Postoperative X-ray films were taken to measure the tibiofemoral angle and tibial angle; knee range of motion, and HSS and WOMAC scores were used to assess the activity of knee. Results The entry point of group B was located in front of the center of tibial plateau, which was inconsistent with the traditional entry point. The incision healed by first intention in all patients of 2 groups. The patients were followed up 6 to 12 months (mean, 8.6 months). The X-ray measurement at 1 week after operation showed no significant difference in tibiofemoral angle between 2 groups (t= — 6.65, P=0.72), but the anteroposterior and lateral tibial angles of group A were significantly lower than those of group B (P lt; 0.05). The knee range of motion, HSS score, and WOMAC score of 2 groups were significantly higher at 3 and 6 months after operation when compared with preoperative values (P lt; 0.05), and the values at 6 months were significantly increased than those at 3 months after operation (P lt; 0.05). HSS score and WOMAC score had no significant difference between 2 groups at 3 months after operation (P gt; 0.05), but the scores of group B were significantly higher than those of group A at 6 months (P lt; 0.05). The knee range of motion of group B was significantly better than that of group A at 3 months after operation (t=2.13, P=0.04), but no significant difference was found between 2 groups at 6 months (t=0.58, P=0.56). Conclusion Compared with the traditional intramedullary guide rod insertion point positioning, digital individualized design of entry point positioning has the advantages of more accurate lower limb force line, better recovery of knee function, and earlier 90°activities, but the long-term effectiveness needs further observation.
Objective To review the research progress of the location marker of rotational alignment of the distal femur. Methods The recent literature concerning the location marker of rotational alignment of the distal femur at home and abroad was extensively reviewed and analyzed. Results Femoral prosthesis malrotational alignment could lead to some patellofemoral complications, such as dislocation of the patella, snapping, wear, and patellar pain. There are many methods to determining femoral component rotational alignment in the artificial total knee arthroplasty, including transepicondylar axis line, anterior posterior axis, the posterior condyles line, flexion gap balance technology, and computer navigation technology. Correct choice of the rotational alignment of the distal femur is crucial in reducing postoperative complications and the revision rate. Suitable reference axis is chosen during total knee arthroplasty to ensure the accuracy of the rotation axis of the femoral prosthesis, but it is currently still controversial. Conclusion The rotational alignment of the distal femur is an extremely important part to affect the prognosis of total knee arthroplasty. The methods to determine the rotational alignment of the distal femur need to be further improved.
Objective To evaluate the influence of patellar replacement on total knee arthroplasty by comparing with non pattelar replacement. Methods Between September 2010 and November 2010, 63 patients (63 knees) with osteoarthritis who met the selection criteria and underwent total knee arthroplasty, were randomly divided into 2 groups: patellar replacement in 32 cases (replacement group), non patellar replacement in 31 cases (non pattelar replacement group). There was no significant difference in gender, age, disease duration, osteoarthritis grading, the clinical and functional scores of American Knee Society Score (KSS), the patellar tilt angle, tibiofemoral angle, and patellar ligament ratio between 2 groups (P gt; 0.05), they were comparable. After 6 weeks, 3, 6, and 12 months of operation, clinical and imaging evaluation methods were used to assessment the effectiveness. Results Primary healing of incision was obtained in all patients of 2 groups. Deep venous thrombosis occurred in 6 cases of replacement group and in 8 cases of non pattelar replacement group. All patients were followed up 12 months. The postoperative incidence of anterior knee pain in replacement group was significantly lower than that in non pattelar replacement group (P lt; 0.05) at 3, 6, and 12 months after operation. No significant difference was found in the postoperative KSS clinical score between 2 groups at each time point (P gt; 0.05). The joint function score of the replacement group was significantly higher than that of the non pattelar replacement group at the other time point (P lt; 0.05) except the score at 6 weeks and 3 months. Significant difference was found in the patella score between 2 groups at 12 months (P lt; 0.05), but no significant difference at the other time points (P gt; 0.05). X-ray film showed no patellar fracture and dislocation, or loosening and breakage of internal fixation. At 12 months after operation, the tibiofemoral angle, the patellar ligament ratio, and the patellar tilt angle showed no significant difference between 2 groups (P gt; 0.05). Conclusion Patella replacement can improve knee function score and the patella score, and reduce the incidence of postoperative anterior knee pain.
Objective To evaluate the influence of patellar non-resurfacing on the effectiveness after total knee arthroplasty (TKA). Methods Between April 2008 and April 2011, 163 patients with degenerative osteoarthritis of the knee underwent TKA without patellar resurfacing, and the clinical data were retrospectively analyzed. There were 65 males and 98 females, with a mean age of 63 years (range, 54-78 years). According to Outerbridge classification for cartilage degeneration, 22 cases were classified as grade I, 38 cases as grade II, 64 cases as grade III, and 39 cases as grade IV. There was no significant difference in gender, age, and sides among patients at 4 grades (P gt; 0.05). The intraoperative tourniquet-using time and postoperative complications were recorded; the knee society score (KSS), patella score (PS), patients’ satisfaction, and anterior knee pain [using visual analogue scale (VAS)] were used to evaluate the knee function. X-ray films were routinely taken to observe the position of the prosthesis and the patella. Results The mean tourniquet-using time was 125 minutes (range, 90-150 minutes). All incisions obtained healing by first intention, and no early postoperative complication occurred. All patients were followed up 2-5 years (mean, 3.6 years). The KSS and PS scores were significantly improved at 6 months and last follow-up when compared with preoperative scores (P lt; 0.05), but no significant difference between at 6 months and last follow-up (P gt; 0.05). Significant differences in KSS and PS scores were found among patients with different grades of cartilage degeneration at preoperation (P lt; 0.05), but no significant difference at last follow-up (P gt; 0.05). At last follow-up, 7 patients experienced anterior knee pain (mild pain in 5, moderate pain in 2). The results of satisfaction were very satisfied in 90 cases, satisfied in 66 cases, not certain in 5 cases, and not satisfied in 2 cases. No significant difference was found in satisfaction and anterior knee pain among patients with different grades of cartilage degeneration (P gt; 0.05). Conclusion Patellar non-resurfacing has no effect on the effectiveness after TKA.
Objective To measure the included angle between tibia anatomical axis and anterior cortex, and to define the relative position of them in order to give direction in placement of tibia extra-medullary alignment bar during total knee arthroplasty. Methods A total of 100 healthy volunteers were included (49 left knees and 51 right knees). There were 52 males and 48 females, aged 20-86 years with an average age of 45.2 years (20-35 years in 29 cases, 35-50 years in 32 cases, and over 50 years in 39 cases). The tibiofibular lateral X-ray films were taken to measure the included angle between tibia anatomical axis and anterior cortex with AutoCAD2004 system. The samples were grouped according to gender, age, and side. Results The included angles between tibia anatomical axis and anterior cortex ranged from 3.007 to 3.021° with an average of 3.001°; the angles were (2.965 ± 0.361)° in male and (3.041 ± 0.311)° in female; the angles were (2.996 ± 0.332)° in the left knee and (3.006 ± 0.347)° in the right knee; and the angles were (2.918 ± 0.346)° in 20-35 years age group, (3.060 ± 0.330)° in 35-50 years age group, and (3.014 ± 0.336)° in over 50 years age group. No significant difference was found in the included angle between tibia anatomical axis and anterior cortex between male and female, among different ages, and between left and right knees (P gt; 0.05). Conclusion The included angle between tibia anatomical axis and anterior cortex is about 3°, so tibia extra-medullary alignment bar should be placed at the angle of 3° with anterior cortex during total knee arthroplasty.
Objective To investigate the methods and effectiveness of surgical treatment for posteromedial corner (PMC) injury combined with anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) ruptures. Methods Between February 2009 and February 2012, 15 patients (15 knees) with PMC injury combined with ACL and PCL ruptures underwent PMC repair with suture anchor and ACL and PCL reconstruction. There were 7 males and 8 females with an average age of 39 years (range, 15-59 years). The causes of injury were traffic accident injury in 6 cases, sport injury in 7 cases, and sprain injury in 2 cases. The disease duration was 3-15 days with an average of 7 days. All patients presented positive results of anterior drawer test, posterior drawer test and valgus stress test, and dysfunction of knee joint. Of 15 cases, 3 had ACL and PCL ruptures, 5 had ACL rupture, 3 had ACL injury at the attachment point of the condyles crest, and 4 had PCL rupture; 9 had PMC tear at the femur insertion, 5 had PMC tear at the tibia insertion, and 1 had PMC tear in the body area. Results All incisions healed by first intention with no complication of infection or stiffness of knee. All cases were followed up 18.4 months on average (range, 10-36 months). At last follow-up, 14 cases had normal knee flexion and extension ranges, but 1 case had 10° limitation of the knee extension. Except 1 case which had weakly positive valgus stress test, the other patients showed negative results of anterior drawer test, posterior drawer test, and valgus stress test. Based on the improved Lysholm classification standard, the results were excellent in 8 cases, good in 5 cases, and fair in 2 cases; the excellent and good rate was 86.7%. Conclusion Early repair of the PMC and reasonable reconstruction of cruciate ligament can effectively restore the knee stability for patients with PMC injury combined with ACL and PCL ruptures.
Objective To explore the application value of self-made tibial mechanical axis locator in tibial extra-articular deformity in total knee arthroplasty (TKA) for improving the lower extremity force line. Methods Between January and August 2012, 13 cases (21 knees) of osteoarthritis with tibial extra-articular deformity were treated, including 5 males (8 knees) and 8 females (13 knees) with an average age of 66.5 years (range, 58-78 years). The disease duration was 2-5 years (mean, 3.5 years). The knee society score (KSS) was 45.5 ± 15.5. Extra-articular deformities included 1 case of knee valgus (2 knees) and 12 cases of knee varus (19 knees). Preoperative full-length X-ray films of lower extremities showed 10-21° valgus or varus deformity of tibial extra joint. Self-made tibial mechanical axis locator was used to determine and mark coronal tibial mechanical axis under X-ray before TKA, and then osteotomy was performed with extramedullary positioning device according to the mechanical axis marker. Results All incisions healed by first intention, without related complications of infection and joint instability. All patients were followed up 5-12 months (mean, 8.3 months). The X-ray examination showed lt; 2° knee deviation angle in the others except 1 case of 2.9° knee deviation angle at 3 days after operation, and the accurate rate was 95.2%. No loosening or instability of prosthesis occurred during follow-up. KSS score was 85.5 ± 15.0 at last follow-up, showing significant difference when compared with preoperative score (t=12.82, P=0.00). Conclusion The seft-made tibial mechanical axis locator can improve the accurate rate of the lower extremity force line in TKA for tibia extra-articular deformity.
Objective To analyze the effect of the posterior cruciate ligament (PCL) retaining or not on knee-joint proprioception by comparing the proprioceptive difference between PCL retaining and no PCL retaining in total knee arthroplasty (TKA). Methods Between June 2009 and June 2010, 38 osteoarthritis patients meeting the inclusion criteria were divided into PCL retaining group (group A, n=19) and PCL-substituting group (group B, n=19) according to the random number table. There was no significant difference in gender, age, disease duration, the range of motion of the knee between 2 groups (P gt; 0.05). The effectiveness and the knee-joint proprioception were separately assessed by the Western Ontario and McMaster University Osteoarthritis Index (WOMAC) score and the passive angle reproduction test (30, 60, and 90° of knee flexion) preoperatively and 12 months postoperatively. Results All incisons healed by first intention, without complications of infection, fracture, and deep vein thrombosis of lower limb. The patients were followed up 12-17 months (mean, 14.1 months). The knee function after operation was obviously improved when compared with preoperative one; significant differences were observed in the WOMAC scores and the results of passive angle reproduction test between at preoperation and at 12 months after operation (P lt; 0.05), but no significant difference was found between group A and group B (P gt; 0.05). Conclusion Whether PCL retaining or not in TKA both can improve knee-joint proprioception, and no obvious difference between them.