Piperfog3592

certain patient populations for this procedure.

Limited studies have examined the relationship between axial rotational alignment and functional outcome in mobile-bearing UKA. The aims of this study was to determine the correlation between component axial rotational alignment and functional outcomes, and to recommend a safety range for component rotation for Oxford UKA.

A retrospective study of 83 Oxford UKA was performed in 67 patients. Postoperative CT scans and clinical assessments were performed at a mean follow up of 21months. Functional outcomes were measured by the OKS, modified KSS and KFS scores. A moving threshold analysis was performed to evaluate the relationship between different rotational alignment cut-off values and functional outcome scores.

The mean femoral and tibial components were positioned with a mean of 4.8° and 7.5° external rotation (ER), respectively. Increasing tibial external rotation was negatively correlated with clinical outcome scores while increasing femoral component rotation did not correlate with clinical outcomes. Better functional scores were observed at mean femoral and tibial rotation angles between 2-6° ER (1.2-6.6°) and 1-8° ER (0.5-8.8°), respectively; with the highest OKS, KSS and FKS observed at 3-4° ER for femoral component, and 4-5° ER for tibial component.

Femoral component axial rotation between 2°- 6° ER, and tibial component axial rotation between 1° and 8° ER correlated with significantly better functional scores. Surgeons should be especially aware of the relatively high variability in tibial component rotation and its implications of functional outcomes.

Femoral component axial rotation between 2°- 6° ER, and tibial component axial rotation between 1° and 8° ER correlated with significantly better functional scores. Surgeons should be especially aware of the relatively high variability in tibial component rotation and its implications of functional outcomes.

To evaluate (1) the outcome of PCL reconstruction with tibial suspensory fixation using a fovea landmark technique based on the tunnel position and serial change of the tunnel configuration after trans-tibial PCL reconstruction, and (2) whether suspensory fixation has any harmful effect on the outcome.

A total of 48 knees that underwent PCL reconstruction were included. The tunnel position was analyzed using CT. To analyze the tunnel configuration, the tunnel diameter, area, and volume were measured. To evaluate the outcome, pre- and postoperative International Knee Documentation Committee (IKDC) and Lysholm scores were analyzed. To evaluate stability, a side-to-side difference was evaluated using Telos stress radiographs.

The greatest configurational change occurred at the mid-portion of tibial tunnel. There was a correlation between stability and tibial tunnel mid-portion configurational change (p<0.01). Important correlations were found between the tunnel position and serial tunnel configuration between high femoral tunnel and widest site of femoral tunnel and tibia aperture (p<0.01 and 0.04, respectively). The diameter of widest site of tibia tunnel increased when the tibia tunnel center moved toward the posterior margin of the tibia (p=0.02) and the percentage of femoral tunnel volume enlargement increased when the tibia tunnel center moved toward the medial edge of the PCL fovea (p=0.02).

A high femoral tunnel, medial tibial tunnel, and posterior tibial tunnel were related to the serial configurational change. A suspensory tibial fixation produced significant configurational change around the mid-portion of the tibial tunnel, and it induced a negative effect on stability.

Level IV.

Level IV.

The patellofemoral joint is often affected by torsionaldisorders of the lower limb, causing pain, instability and knee degeneration. The aims of this study were to determine functional outcomes of patients who underwent a high tibial derotation osteotomy (HTDO) for symptomatic squinting patella due to increased external tibial torsion. Moreover, factors associated with inferior clinical outcomes were investigated.

Patients with symptomatic squinting patella, increased external tibial torsion (>30°) treated with this technique, and with 2years of follow up were included. Fulkerson and Kujala patellofemoral joint scores were assessed. H1152 Age, body mass index, history of prior surgery, increased femoral anteversion, association of lateral retinaculum release and patellar cartilage lesions were analysed.

Sixty HTDOs were included in this retrospective study with an average of 66months of follow up. The mean Kujala score improved from 47.5 preoperatively to 93 postoperatively. The mean Fulkerson score improved from 40.6 to 91.6. Kujala subscores for pain improved from 8.6 to 30.4, for instability improved from 6.4 to 17.9, and their ability to climb stairs increased from 6.9 to 17.9 (all P<0.0001). Multivariate logistic regression model identified that patient age (P<0.005) and advanced chondral damage (P<0.001) were the dominant factors predicting inferior clinical outcomes using Kujala's score.

HTDO provided good results regarding the pain symptoms, instability and the ability to climb stairs. Advanced chondral damage and advanced age had negative effects on outcomes.

HTDO provided good results regarding the pain symptoms, instability and the ability to climb stairs. Advanced chondral damage and advanced age had negative effects on outcomes.

Although the medial joint space width (MJSW) is commonly used for radiographic evaluation of knee osteoarthritis, the changes in knee joint space width (JSW) during weight bearing after medial opening-wedge high tibial osteotomy (MOWHTO) remain unclear. This study aimed to depict how medial and lateral JSWs and convergence angles change gradually after MOWHTO.

We retrospectively followed up 81 MOWHTO cases for over 45months on average. Pre- and postoperative mechanical axes were recorded. The JSWs and convergence angles were measured preoperatively, immediately postoperatively, and 3-6, 9-12, and 21-24months postoperatively. Patient-reported outcomes were measured using a visual analogue scale (VAS).

The mean mechanical femoral-tibial angle improved from 8.1° varus to 2.4° valgus. At the aforementioned times, the respective mean values of MJSW were 2.6, 3.5, 3.8, 4.0, and 4.2mm; mean convergence angles were 4.8°, 2.9°, 2.2°, 2.1°, and 1.9°; and the mean VAS scores were 7.2, 7.8, 4.8, 1.4, and 1.3. The MJSW continued to increase significantly in the first year postoperatively and then plateaued for a minimum of 2years follow up after MOWHTO.