The effect of self-reported knee instability on plantar pressure and postural sways in women with knee osteoarthritis

Background Giving way and knee instability are common problems in patients with knee osteoarthritis, disrupting the daily activities and balance of the affected individual. The present study aimed to evaluate the postural control status of women with knee osteoarthritis with and without self-report knee instability (KI). Methods This cross-sectional, single-blind study was conducted on 57 female patients with knee osteoarthritis. The patients were selected based on the inclusion and exclusion criteria and divided into two groups of with KI (n = 26) and without KI (n = 31). Fear of movement was assessed using the Tampa questionnaire, the degree of knee instability was measured based on the Fitzgard scale, the static and dynamic balance of the subjects were evaluated with open and closed eyes using a Biodex balance device, and foot pressure distribution situation was measured using a FDM-S-Zebris device. Results Mean comparison showed a significant difference between the subjects with and without KI in static balance only in anterior–posterior direction with open eyes (p = 0.01) and closed eyes (p = 0.0001). In the dynamic balance test, the subjects in both groups had significant differences in terms of all the indicators of anterior–posterior stability (p = 0.001), medial–lateral stability (p = 0.0001), and overall stability (p = 0.0001) with closed eyes. However, no significant difference was observed with open eyes (p > 0.05). Multiple regression also indicated significant positive correlations between pain intensity and disease duration with the degree of KI (p < 0.05). Conclusions According to the results, there were significant differences between the mean pain scores, static and dynamic balance, and the rate of fall between the women with knee osteoarthritis with and without the KI index. Therefore, patients with knee osteoarthritis, which also has an index of KI, are more susceptible to falls, and proper strategies are required to reduce the level of KI in these patients.

Total Knee Arthroplasty in Patients With Prior Ipsilateral Hip Fusion: A Surgical Technique

Background: In patients with severe osteoarthritis of the knee with prior ipsilateral hip fusion who require total knee arthroplasty (TKA), a controversial issue is whether to first convert the hip fusion to a total hip arthroplasty (THA) or to perform TKA without reconstruction of the hip. Also, immobility of the ipsilateral, fused hip adds significant technical challenge because the usual positioning of the leg requires modification in order to gain access needed for the TKA. Technique: In such cases, we position the patient with the knee suspended, similar to how we perform knee arthroscopy. In our experience, the ipsilateral knee has significant deformity and is best addressed with a constrained, hinged TKA. Results: In 3 patients with severe knee osteoarthritis with prior ipsilateral hip fusion—a 72-year-old man and a 79-year-old woman with hip arthrodesis due to posttraumatic arthritis and an 81-year-old woman with hip arthrodesis due to congenital dislocation of the hip—rotating-hinge knee prostheses were implanted due to severe knee instability. All 3 patients had satisfactory results, without complications, after follow-up of 1 to 5 years. Conclusions: We obtained satisfactory results in the short and medium term without previously converting the hip arthrodesis to THA by positioning patients with the knee suspended, in a way similar to when knee arthroscopy is performed, and implanting rotating hinge TKAs due to severe preoperative knee instability.

MRI findings of acute anterior instability of the knee in the absence of recent trauma

Background Anterior knee instability is usually encountered in the context of trauma, with the clinical examination and imaging focusing on anterior cruciate ligament (ACL) disruption. Limited data exist on magnetic resonance imaging (MRI) of acute anterior knee instability in the absence of recent trauma. Purpose To provide the first comprehensive account of MRI findings in acute anterior knee laxity in the absence of acute trauma and to evaluate predictors of ACL integrity and pain. Material and Methods A total of 84 consecutive patients with non-traumatic knee instability were prospectively studied. Instability was assessed with Lachman’s, pivot shift, and Lelli’s tests. MRI findings were recorded, and ACL integrity was surgically confirmed in all 24 cases of MRI suggesting tear and in 21/60 cases of MRI suggesting no tear. Binary logistic regression models were used to identify predictors of ACL tears and pain, and Mann–Whitney U test served for comparisons between continuous variables. The study was approved by the institutional review board. Results Osteoarthritis and notch bony outgrowth (NBO) were present in 44% and 42.9% of all knees, respectively. NBO did not correlate with osteoarthritis ( P = 0.606). NBO (odds ratio [OR] = 4.157; P = 0.016) and ACL grafts (OR = 9.277; P = 0.01) predisposed to non-traumatic ACL tears (torn in 28.6% of total cases). Presence of osteoarthritis was predictive of pain (OR = 17.671; P < 0.001). Conclusion We present a comprehensive analysis of MRI findings in clinically significant non-traumatic anterior instability, showing that NBO and ACL grafts predispose in non-traumatic ACL tears, whereas osteoarthritis is the only predictor of pain.

Feasibility study of early prediction of postoperative MRI findings for knee stability after anterior cruciate ligament reconstruction

Background At present, the most effective and mature treatment after ACL injury and tear is ACL reconstruction, but the rehabilitation process after ACL reconstruction that is very long, so it is very important to find early MRI positive findings of knee instability. Methods We retrospectively collected the clinical and imaging data of 70 patients who underwent ACL reconstruction from January 2016 to December 2019; Based on clinical criteria, the patients were divided into a stable group (n = 57) and an unstable group (n = 13); We measured the MRI imaging evaluation indexes, including the position of the bone tunnel, graft status, and the anatomical factors; Statistical methods were used to compare the differences of imaging evaluation indexes between the two groups; The prediction equation was constructed and ROC curve was used to compare the prediction efficiency of independent prediction factors and prediction equation. Results There were significant differences in the abnormal position of tibial tunnel entrance, percentage of the position of tibial tunnel entrance, position of tibial tunnel exit, lateral tibial posterior slope (LTPS), width of intercondylar notch between stable knee joint group and unstable knee joint group after ACL reconstruction (P < 0.05); The position of tibial tunnel exits and the lateral tibial posterior slope (LTPS) and the sagittal obliquity of the graft were independent predictors among surgical factors and self-anatomical factors (P < 0.05); The prediction equation of postoperative knee stability was established: Logit(P) = -1.067–0.231*position of tibial tunnel exit + 0.509*lateral tibial posterior slope (LTPS)-2.105*sagittal obliquity of the graft; The prediction equation predicted that the AUC of knee instability was 0.915, the sensitivity was 84.6%, and the specificity was 91.2%. Conclusions We found that abnormalities of the position of the exit of the bone tunnel, lateral tibial posterior slope (LTPS) and sagittal obliquity of the graft were the early MRI positive findings of knee instability after ACL reconstruction. It is helpful for clinicians to predict the stability of knee joint after ACL reconstruction.