Does robotic technology successfully restore the joint line after total knee arthroplasty? A retrospective analysis

Background Our study aims to determine the effectiveness of robotic technology for total knee arthroplasty in the successful restoration of the joint line of the knee with respect to that of a normal human anatomical knee. The restoration of the joint line is an important technical goal on which the postoperative outcomes and the success of the surgery depend. Methods Sixty-four postoperative plain anteroposterior radiographs of 60 patients, who received total knee arthroplasty by using the robotic technology were analyzed and compared with 66 similar radiographs of 60 patients who received the conventional method. The distances of the lateral epicondyle to the joint line (LEJL) and proximal tibiofibular joint to the joint line (PTFJJL) were calculated and analyzed. Results We found that the mean value of LEJL minus PTFJJL in the robotic group was 0.334 ± 0.115 (mean ± SD), while in the conventional group, it was 2.304 ± 0.308. The difference between the two groups was statistically significant. The mean ratio (LEJL:PTFJJL) in the robotic group was also equal to 1.017 ± 0.042. Conclusion From these findings it could be concluded that the robotic technology significantly increases the accuracy of the total knee arthroplasty and, compared to the conventional method, achieves an almost anatomical position of the joint line.

Associations Between the Morphological Parameters of Proximal Tibiofibular Joint (PTFJ) and Changes in Tibiofemoral Joint Structures in Patients with Knee Osteoarthritis

BackgroundTo describe the longitudinal associations between the morphological parameters of proximal tibiofibular joint (PTFJ) and joint structural changes in tibiofemoral compartments in patients with knee osteoarthritis (OA).MethodsThe participants were selected from the Vitamin D Effects on Osteoarthritis (VIDEO) study. PTFJ morphological parameters were measured on coronal and sagittal MRI. The contacting area (S) of PTFJ, and its projection areas onto the horizontal (load-bearing area, Sτ), sagittal (lateral stress-bolstering area, Sφ) and coronal plane (posterior stress-bolstering area, Sυ) were assessed. Knee structural abnormalities, including cartilage defects, bone marrow lesions (BMLs) and cartilage volume, were evaluated at baseline and after 2 years. Log binominal regression models and linear regression models were used to assess the associations between PTFJ morphological parameters and osteoarthritic structural changes.ResultsIn the longitudinal analyses, the S (RR: 1.45) and Sτ (RR: 1.55) of PTFJ were significantly and positively associated with an increase in medial tibial (MT) cartilage defects. The Sτ (β: -0.07), Sυ (β: -0.07), and S (β: -0.06) of PTFJ were significantly and negatively associated with changes in MT cartilage volume. The Sτ (RR: 1.55) of PTFJ was positively associated with an increase in MT BMLs, and Sφ (RR: 0.35) was negatively associated with an increase in medial femoral BMLs. ConclusionsThis longitudinal study suggests that higher load-bearing area of PTFJ could be a risk factor for structural changes in medial tibiofemoral (MTF) compartment in knee OA. This may provide a theoretical support for proximal fibular osteotomy in the treatment of MTF OA.Trial registration: Clinicaltrials.gov Identifier: NCT01176344; Anzctr.org.au Identifier: ACTRN12610000495022Date of registration: 7 May 2010