ObjectiveTo investigate the effect of anterior cruciate ligament (ACL) integrity on the short- and mid-term effectiveness of mobile-bearing medial unicompartmental knee arthroplasty (UKA). MethodsThe clinical data of 128 patients with anteromedial osteoarthritis who underwent mobile-bearing medial UKA between June 2019 and June 2021 was retrospectively analyzed. According to the integrity of ACL structure under direct vision during operation, the patients were divided into normal group (30 cases), synovial defect group (53 cases), and longitudinal split group (45 cases). There was no significant difference in gender, age, body mass index, preoperative knee range of motion (ROM), hip-knee-ankle angle (HKA), Knee Society Score (KSS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and other baseline data among the 3 groups (P>0.05). The knee ROM, KSS score (including clinical and functional scores), WOMAC score (including pain, stiffness, and function scores) before operation and at last follow-up, the Lysholm score, International Knee Documentation Committee (IKDC) score, and Forgetting Joint Score (FJS-12) at last follow-up were recorded and compared among the 3 groups. Imaging examination was performed to evaluate the wear of cartilage in the lateral tibiofemoral compartment and patellofemoral compartment of the knee joint. HKA and posterior tibial slope (PTS) were measured at last follow-up. ResultsAll the patients of 3 groups were followed up 22-56 months (mean, 40.4 months). There was no significant difference in follow-up time among the 3 groups (P>0.05). At last follow-up, imaging examination showed no obvious cartilage wear progression of the lateral tibiofemoral compartment and patellofemoral compartment, and no adverse events such as aseptic loosening of the prosthesis, dislocation of the removable pad, or infection occurred during the follow-up. At last follow-up, knee ROM, HKA, KSS scores, and WOMAC scores of the 3 groups significantly improved when compared with preoperative ones (P<0.05). There was no significant difference in the changes of the above indicators before and after operation, and also the Lysholm score, IKDC score, FJS-12 score, and PTS among the 3 groups (P>0.05). ConclusionThe integrity of ACL has no significant effect on the short- and mid-term effectiveness of mobile-bearing medial UKA.
Objective To investigate the reliability of determining rotational positioning of femoral prosthesis using the coronal transverse tibial axis at 90° of knee flexion as the reference in total knee arthroplasty (TKA). Methods Fifty-five patients with knee osteoarthritis undergoing TKA between November 2020 and February 2026 who met the selection criteria were enrolled. There were 14 males and 41 females, aged 54-82 years, with a mean age of 66.4 years. Preoperative knee CT and full-length lower-extremity X-ray films were performed to measure the hip-knee-ankle angle (HKA) and posterior condylar angle (PCA). During surgery, after distal femoral osteotomy, the knee was maintained at 90° of flexion, and the tibial transverse axis (line a) perpendicular to the coronal projection of the tibial mechanical axis was marked on the osteotomy surface. Following tibial osteotomy and gap balancing, the external rotation line of the femoral component (line b) was determined. The final external rotation osteotomy angle was established based on the above references, and four-in-one positioning pins were fixed according to this angle. The line connecting the positioning pins served as the known external rotation reference line (line r). Accordingly, the external rotation angles of Line a and Line b relative to the posterior condylar line of the femur (∠A, ∠B) were calculated separately. The differences among PCA, ∠A, and ∠B were compared, and the correlation between ∠A and ∠B,∠A and HKA were analyzed. In addition, the distribution of ∠A in and around the “safe zone” (between PCA and ∠B) was counted. Results Preoperative HKA was (7.3±3.7)°, and PCA, ∠A, and ∠B were (3.1±1.4)°, (4.6±2.4)°, and (4.7±2.1)°, respectively. Compared with PCA, both ∠A and ∠B demonstrated greater external rotation, with significant differences (P<0.05); no significant difference was found between ∠A and ∠B (P>0.05). Correlation analysis revealed significant correlations between ∠A and ∠B, as well as between ∠A and HKA (r=0.674, P<0.001; r=0.350, P=0.009). In 45% (25/55) of patients, ∠A was between PCA and ∠B, which was within the “safe zone”. Conclusion The transverse tibial axis at 90° of knee flexion during TKA serves as a reliable reference for determining rotational positioning of femoral prosthesis. The severity of preoperative knee varus deformity correlates with the external rotation angle defined by this transverse tibial axis, and this angle shows high consistency with that derived from the gap balancing technique.
Objective To investigate short-term effectiveness and clinical application advantages of orthopedic robot-assisted resection for osteoid osteoma compared with traditional open surgery. Methods A retrospective analysis was conducted on clinical data of 48 osteoid osteoma patients who met the selection criteria between July 2022 and April 2023. Among them, 23 patients underwent orthopedic robot-assisted resection (robot-assisted surgery group), and 25 patients received traditional open surgery (traditional surgery group). There was no significant difference (P>0.05) in gender, age, disease duration, lesion location and size, and preoperative visual analogue scale (VAS) score, and musculoskeletal tumor society (MSTS) score between the two groups. The surgical time, intraoperative blood loss, intraoperative lesion localization time, initial localization success rate, infection, and recurrence were recorded and compared. VAS scores before surgery and at 24 hours, 1, 3, 6, and 9 months after surgery and MSTS score before surgery and at 3 months after surgery were assessed. Results All patients completed the surgery successfully, with no significant difference in surgical time between the two groups (P>0.05). Compared to the traditional surgery group, the robot-assisted surgery group had less intraoperative blood loss, shorter lesion localization time, and shorter hospitalization time, with significant differences (P<0.05). The initial localization success rate was higher in the robot-assisted surgery group than in the traditional surgery group, but the difference between the two groups was not significant (P>0.05). All patients in both groups were followed up, with the follow-up time of 3-12 months in the robot-assisted surgery group (median, 6 months) and 3-14 months in the traditional surgery group (median, 6 months). The postoperative MSTS scores of both groups improved significantly when compared to those before surgery (P<0.05), but there was no significant difference in the changes in MSTS scores between the two groups (P>0.05). The postoperative VAS scores of both groups showed a gradually decreasing trend over time (P<0.05), but there was no significant difference between the two groups after surgery (P>0.05). During follow-up, except for 1 case of postoperative infection in the traditional surgery group, there was no infections or recurrences in other cases. There was no significant difference in the incidence of postoperative infection between the two groups (P>0.05). Conclusion Orthopedic robot-assisted osteoid osteoma resection achieves similar short-term effectiveness when compared to traditional open surgery, with shorter lesion localization time.