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Introduction: Para-articular osteochondromas are rare osteocartilaginous tumors arising adjacent to the joint, more common around the knee. In contrast to osteochondroma, they occur in elderly patients. Case Report: We report a 60-year-old female with slow-growing, extraosseous soft tissue mass in the infrapatellar fat pad region with coexisting osteoarthritis. Total excision of the mass with total knee arthroplasty (TKA) done. The patient had excellent functional outcome with no recurrence at 2-year follow-up. Conclusion: The incidence of para-articular osteochondromas in elderly patients with coexisting osteoarthritis is very rare. Clinicoradiological features along with histopathology confirm its diagnosis. Total excision is the mainstay of treatment along with TKA if there is coexisting arthritis and its recurrence is very rare.

Purpose:Tibial bowing in valgus knees with arthritis can lead to component malplacement during total knee arthroplasty (TKA). Incidence of valgus knees with medial tibial bowing, its effect on tibial component placement during primary TKA and methods to improve accuracy of the component placement were studied.Methods:Full-length weight-bearing alignment radiograph was taken in 117 patients (149 knees) with valgus deformity undergoing TKA. In these cases, the proximal tibial reference for extramedullary jig placement was planned preoperatively with reference to the tibial spines and classified as four zones.Results:The mean preoperative hip–knee–ankle (HKA) angle was 192.9° (180.3–234.5°). Bowing >3° was considered significant ( p < 0.001) and at this level of bowing, the proximal tibial reference was shifted from centre to medial. Tibial bowing 3° as tibia valga. Tibia was bowed in 70 knees (46.97%). Severity of valgus deformity had strong positive correlation with the tibia valga ( p < 0.001). The post-operative medial proximal tibial angle (MPTA) and HKA angle were 91.63° (87.9–95.7°) and 182.6° (178.1–189.7°), respectively. The mean MPTA and post-operative HKA angle in bowed and straight tibiae were 90.35° versus 89.78° ( p = 0.547) and 181.5° versus 180.7° ( p = 0.5716), respectively, and the difference was not statistically significant.Conclusion:Medial tibial bowing is very common in valgus knees. Tibia valga has a strong positive correlation with the severity of valgus deformity. Accurate tibial component placement can be achieved with a medialized reference point for extramedullary tibial cutting jig in knees with significant tibia valga. The study has been registered in clinical trials registry – India (CTRI/2018/03/012283).

Our aim was to determine the variation in valgus correction angle and the influence of individualised distal femoral cut on femoral component placement and limb alignment during total knee replacement (TKR) in knees with varus deformity.The study was done prospectively in two stages. In the first stage, the valgus correction angle (VCA) was calculated in long-limb radiographs of 227 patients and correlated with pre-operative parameters of femoral bowing, neck-shaft angle and hip-knee-ankle angle. In the second part comprising of 240 knees with varus deformity, 140 (group 1) had the distal femoral cut individualised according to the calculated VCA, while the remaining 100 knees (group 1) were operated with a fixed distal femoral cut of 5°. The outcome of surgery was studied by grouping the knees as varus10°, 10-15° and15°.Of the 227 limbs analysed in stage I, 70 knees (31 %) had a VCA angle outside 5-7°. Coronal bowing (p 0.001), neck-shaft angle (p 0.001) and preoperative deformity (p 0.001) significantly influenced VCA. Results of the second phase of the study showed a significant improvement in both femoral component placement and postoperative alignment when VCA was individualised in the groups of knees with varus 10-15° (p 0.002) and varus15° (p 0.002).Valgus correction angle is highly variable and is influenced by femoral bowing, neck-shaft angle and pre-operative deformity. Individualisation of VCA is preferable in patients with moderate and severe varus deformity.Level 2.

Lateral tibial bowing leads to varus placement of the tibial component during total knee replacement in varus knees. Lateralised tibial jig placement can improve the accuracy of the tibial cut.A total of 227 patients (300 knees) undergoing total knee replacements were randomised into two groups. In the study group, the point of intersection of the distal tibial diaphyseal line at the tibial plateau drawn on long films was represented by zones. Knees with femoral bowing5° (28%) were excluded. Tibial jig placement on the proximal tibia was lateralised according to the zones. In the control group, the mid-point of the tibial plateau was taken as a reference. Femoral and tibial bowing, postoperative limb alignment and component placement were assessed.Of the 216 knees that were studied, 106 were in the study group and 110 in the control group. Bowing ≥3° had a significant positive correlation with lateralisation of the proximal tibial reference (p 0.001). The Incidence of tibial bowing ≥3° was 57.33%. The mean postoperative hip-knee-ankle (HKA) angle was 178.31 ± 2.88° and 176.53 ± 2.88° (p 0.001), whereas the mean medial proximal tibial angle (MPTA) was 89.91 ± 1.42° and 88.79 ± 1.72° (p 0.001) in the study and control groups, respectively. Considering bowed tibiae alone, HKA angle and MPTA in the study group were 178.08 ± 2.81° and 89.72 ± 1.39° compared with 175.88 ± 2.87° and 88.38 ± 1.38° in the control group (p 0.001).There is a high incidence of tibial bowing in varus knees. Lateralised tibial jig placement improved tibial component placement and postoperative limb alignment in total knee arthroplasty in varus knees with tibial bowing.