Objective To investigate the difference of total knee arthroplasty (TKA) with tantalum monoblock tibial component (TMT) and cemented tibial plateau prosthesis in patients of different ages. Methods The clinical data of 248 patients (392 knees) who underwent primary TKA between May 2014 and May 2019 and met the selection criteria were retrospectively analyzed. There were 54 males (98 knees) and 194 females (294 knees). Of the 122 patients (183 knees), less than 65 years old, 52 (75 knees, group A1) were treated with TMT and 70 (108 knees, group B1) were treated with cemented tibial plateau prosthesis; of the 126 patients (209 knees), more than 65 years old, 57 (82 knees, group A2) were treated with TMT and 69 (127 knees, group B2) were treated with cemented tibial plateau prosthesis. The baseline data of patients, perioperative indicators [hemoglobin (Hb), hematocrit (Hct), total blood loss, unilateral operation time], effectiveness evaluation indicators [Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, visual analogue scale (VAS) score, Knee Society Scoring System (KSS) score, active flexion and extension range of motion (ROM) of the knee joint], complications, and imaging indicators [tibial prosthesis varus angle (β angle), tibial prosthesis posterior slope angle (δ angle), tibio-femoral angle, occurrence of radiolucent line, prosthesis survival rate] were recorded and compared. Results There was no significant difference in gender, age, height, weight, body mass index, Kellgren-Lawrence grading, the length of hospital stay, and follow-up time between groups A1, B1 and groups A2, B2 (P>0.05). The unilateral operation time in groups A1 and A2 was significantly shorter than that in the corresponding groups B1 and B2 (P<0.05). There was no significant difference in differences of pre- and post-operative Hb and Hct and total blood loss between groups A1, B1 and groups A2, B2 (P>0.05). There was no significant difference in preoperative effectiveness evaluation indicators between groups A1, B1 and groups A2, B2 (P>0.05). There were significant differences in the differences of pre- and post-operative WOMAC activity and pain scores, KSS function and pain scores, and VAS scores between groups A1 and B1 (P<0.05); there was no significant difference in WOMAC stiffness score and ROM (P>0.05). There was no significant difference in the above indicators between groups A2 and B2 (P>0.05). There was no significant difference in the incidence of complications (2.7% vs 6.5%, 3.7% vs 3.1%) and prosthesis survival rate (100% vs 97.2%, 100% vs 99.2%) between groups A1, B1 and groups A2, B2 (P>0.05). During follow-up, there was no significant difference in β angle, δ angle, and tibio-femoral angle between groups A1, B1 and groups A2, B2 (P>0.05). In the evaluation of knee X-ray radiolucent line, 2 knees of group A1 and 2 knees of group A2 had radiolucent line at prosthesis-bone interface immediately after operation, and the radiolucent line was gradually filled by new bone, without new radiolucent line. During follow-up, 1 knee of group B1 and 1 knee of group B2 had prosthesis-bone interface radiolucent line, without radiolucent line widening or prosthesis loosening. Conclusion TMT is recommended in patients less than 65 years old, and the two types of prostheses are available for patients nore than 65 years old. However, the long-term effectiveness of the two types of prosthesis in patients of different ages needs further follow-up.
Objective To investigate the influence of tibial component posterior slope angle (TCPSA) on the short- and mid-term effectiveness of unicompartmental knee arthroplasty (UKA). MethodsThe clinical data of the patients with anterior medial knee osteoarthritis (KOA) treated by UKA between May 2014 and May 2019 were retrospectively analysed. There were 10 males and 45 females with a median age of 68 years (range, 49-83 years). The body mass index (BMI) was 27.63-52.26 kg/m2, with an average of 40.04 kg/m2. There were 28 cases of left knee, 21 cases of right knee, and 6 cases of double knees. The disease duration was from 7 months to 12 years, with an average of 4.33 years. Measurements of posterior tibial slope (PTS) and TCPSA were performed on the knee joint X-ray films of patients before operation and at last follow-up, respectively. According to the postoperative TCPSA, patients were divided into TCPSA<4° group (group A), 4°≤TCPSA<9° group (group B), and TCPSA>9° group (group C) with the quartile method. Baseline data such as age, gender, BMI, and affected side were compared among the 3 groups, as well as the Hospital for Special Surgery (HSS) score, visual analogue scale (VAS) score, and range of motion (ROM) before and after operation. ResultsAll 55 patients were followed up 17-72 months, with an average of 36 months. No complication such as prosthesis loosening, infection, tibial plateau collapse, and dislocation of the meniscus pad occurred. The preoperative PTS was (7.38±3.37)°, and the postoperative TCPSA was (6.25±3.22)°, showing no significant difference (t=1.815, P=0.074). According to postoperative TCPSA, there were 12 knees in group A, 32 in group B, and 17 in group C. There was no significant difference in age, gender, BMI, affected side, and preoperative HSS scores, ROM, and VAS scores among the 3 groups (P>0.05). At last follow-up, the HSS scores, ROM, and VAS scores of the 3 groups significantly improved when compared with preoperative ones (P<0.05). There was no significant difference in the difference of the above indicators before and after operation among 3 groups (P>0.05). ConclusionThe patients with anterior medial KOA may have good short- and mid-term effectiveness after UKA. Among the recommended range of TCPSA, there is no significant influence on the postoperative short- and mid-term effectiveness. Long-term effectiveness need to extend the follow-up time and expand the sample size for research verification.
Objective To investigate the accuracy of the modified Akagi line which referenced the patellar tendon at the attachment and the geometrical center point of the tibial osteotomy surface for tibial rotational alignment. Methods Between July 2021 and December 2021, 72 patients who underwent three-dimension (3D) CT for varus osteoarthritis knees were enrolled. Among 72 patients, 18 were male and 54 were female with a mean age of 64.9 years (range, 47-84 years). The preoperative hip-knee-ankle angle ranged from 0° to 26°, with a mean of 9.3°. CT images were imported into Mimics 21.0 medical image control system to establish 3D models of the knees. The prominent point of lateral epicondyle and the medial epicondylar sulcus were identified in femoral 3D models to construct the surgical transepicondylar axis and the vertical line of its projection [anteroposterior (AP) axis]. In tibial 3D models, the patellar tendon at the attachment was used as anatomical landmarks to construct rotational alignment for tibial component, including the line connecting the medial border of the patellar tendon at the attachment (C) and the middle (O) of the posterior cruciate ligament insertion (Akagi line), the line connecting the point C and the geometric center (GC) of the tibial osteotomy plane [medial border axis of the patellar tendon (MBPT)], the line connecting the medial sixth point of the patellar tendon at the attachment and the point GC [medial sixth axis of the patellar tendon (MSPT)], the line connecting the medial third point of the patellar tendon at the attachment and point O [medial third axis of the patellar tendon 1 (MTPT1)], and the line connecting the medial third point of the patellar tendon at the attachment and point GC [medial third axis of the patellar tendon 2 (MTPT2)]. The angles between the five reference axes and the AP axis were measured, and the distribution of the rotational mismatch angles with the AP axis was counted (≤3°, 3°-5°, 5°-10°, and >10°). Results Relative to the AP axis, the Akagi line and MBPT were internally rotated (1.6±5.9)° and (2.4±6.9)°, respectively, while MSPT, MTPT1, and MTPT2 were externally rotated (5.4±6.6)°, (7.0±5.8)°, and (11.9±6.6)°, respectively. There were significant differences in the rotational mismatch angle and its distribution between reference axes and the AP axis (F=68.937, P<0.001; χ2=248.144, P<0.001). The difference between Akagi line and MBPT showed no significant difference (P=0.067), and the differences between Akagi line and MSPT, MTPT1, MTPT2 were significant (P<0.012 5). ConclusionWhen the position of the posterior cruciate ligament insertion can not be accurately identified on total knee arthroplasty, MBPT can be used as the modified Akagi line in reference to the geometrical center point of the tibial osteotomy surface to construct a reliable rotational alignment of the tibial component.