## 3 Results  
### Clinical Results  
The median age at the time of surgery was 51 years (range: 38-58 years), while median follow-up was 60 months, ranging from 24 months to 120 months. The median latency to start correction was 6 days (range 5-10 days), and the median duration of correction was 16 days (range 10-20 days). An additional correction program was required in 1.8% of all cases. The median required total angle of correction according to the TSF's program prescription given to the patients was 12\({}^{\circ}\) (range 5-18\({}^{\circ}\)). In nine patients (16% of all patients), a 2-5 mm of anterior translation of the tibial tubercle was made in order to decompress the patellofemoral joint. Radiographically, a median FTAm correction of 5\({}^{\circ}\) (range: 3-8\({}^{\circ}\)) was achieved and there was no virtual change in tibia slope. The median time of frame removal was 87 days (range 82-120 days). In Figure 3, a typical radiograph at the end of the correction period is shown. The clinical results are summarized in Table 2.  
\begin{table}
\begin{tabular}{c c} \hline
**Patients’ Post-Operative Data** & **Total Number/Range** \\ \hline Median follow up (months) & 60 \\ \hline Range of follow up (months) & 24–120 \\ \hline Median latency to start correction (days) & 6 \\ \hline Range of latency to start correction (days) & 5–10 \\ \hline Median duration of correction (days) & 16 \\ \hline Range of duration of correction (days) & 10–20 \\ \hline Additional correction program required (\% of all patients) & 1.8 \\ \hline Median required total angle of correction & 12\({}^{\circ}\) \\ \hline Range of total angle of correction & (5–18\({}^{\circ}\)) \\ \hline Median FTAm correction & 5\({}^{\circ}\) \\ \hline Range of FTAm correction & 3–8\({}^{\circ}\) \\ \hline Median time of frame removal (days) & 87 \\ \hline Range of time of frame removal (days) & 82–120 \\ \hline \end{tabular}
\end{table}
Table 2: Clinical results.  
The measurements included in the study were presented using the median and range values, since the Shapiro-Wilk test of normality showed a significant deviation from normality for all the variables of interest. The statistical level of significance was set at 0.05 in all cases and the calculations were carried out with the use of SPSS v23.0 software.  
With regard to the classification defined in Section 2.1, callus formation at the site of osteotomy was eccentric in all cases examined, regardless of patients' gender and whether the patellofemoral compartment arthritis was present pre-operatively or not. As depicted in Figure 4, the consolidation process started from the posterolateral corner of the osteotomy gap and advanced anteromedially. A small uncovered area at the anteromedial part of the osteotomy site was evident at the time of frame removal in 40 cases (73% of all patients), while in the remaining 15 cases (27% of all patients) eccentric callus was formatted in the entire osteotomy gap.  
Ten patients (18% of all patients) had a documented pin track infection, which necessitated the use of oral antibiotic therapy in six patients. There was no case of chronic bone infection. Two patients (3.6% of all patients) sustained deep vein thrombosis, with one case leading to pulmonary embolism that was treated uneventfully.  
At the last follow up there was one patient who lost the initial correction after the apparently premature removal of the frame. None of the remaining patients required another operation or a total knee arthroplasty.  
Figure 3: Radiographs of a representative case at the end of the correction period. Callus formation eccentric pattern is marked with red circles: (**A**) anteroposterior and (**B**) lateral views.