CoxaPro > Clinical Library > Welcome to the joint replacement clinical library > Both modular and nonmodular tapered fluted titanium stems are commonly used in revision total hip arthroplasty (THA). However, which type of femoral stem is superior remains controversial. The purpose of this study was to assess the clinical and radiographic outcomes of modular and nonmodular tapered fluted titanium. The clinical data of patients undergoing primary revision THA from January 2009 to January 2013 in two institutions were retrospectively analyzed. According to the type of prosthesis used on the femoral side, the patients were divided into the modular group (108 hips; Link MP modular stem in 73 hips and AK-MR modular stem in 35 hips) and nonmodular group (110 hips; Wagner SL stem in 78 hips and AK-SL stem in 32 hips). The operative time, hospital stay, blood loss, blood transfusion volume, hip function, hip pain, limb length discrepancy, imaging data, and complications were compared between the two groups.A total of 218 patients were followed up for 78–124 months, with an average of 101.5 months. The incidence of intraoperative fracture in the modular group (16.7%) was significantly higher than that in the nonmodular group (4.5%; (P < 0.05). At the last follow-up, the limb length difference in the modular group (2.3 ± 2.7 mm) was significantly lower than that in the nonmodular group (5.6 ± 3.5 mm; P < 0.05), and the postoperative prosthesis subsidence in the modular group (averaged 0.92 mm; 0–10.2 mm) was significantly less than that in the nonmodular group (averaged 2.20 mm; 0–14.7 mm; P < 0.05). Both modular and nonmodular tapered fluted titanium stems can achieve satisfactory mid-term clinical and imaging results in patients who underwent femoral revision. The modular stems have good control of lower limb length and low incidence of prosthesis subsidence.
Sci Rep. 2020; 10: 14068.

Both modular and nonmodular tapered fluted titanium stems are commonly used in revision total hip arthroplasty (THA). However, which type of femoral stem is superior remains controversial. The purpose of this study was to assess the clinical and radiographic outcomes of modular and nonmodular tapered fluted titanium. The clinical data of patients undergoing primary revision THA from January 2009 to January 2013 in two institutions were retrospectively analyzed. According to the type of prosthesis used on the femoral side, the patients were divided into the modular group (108 hips; Link MP modular stem in 73 hips and AK-MR modular stem in 35 hips) and nonmodular group (110 hips; Wagner SL stem in 78 hips and AK-SL stem in 32 hips). The operative time, hospital stay, blood loss, blood transfusion volume, hip function, hip pain, limb length discrepancy, imaging data, and complications were compared between the two groups.A total of 218 patients were followed up for 78–124 months, with an average of 101.5 months. The incidence of intraoperative fracture in the modular group (16.7%) was significantly higher than that in the nonmodular group (4.5%; (P < 0.05). At the last follow-up, the limb length difference in the modular group (2.3 ± 2.7 mm) was significantly lower than that in the nonmodular group (5.6 ± 3.5 mm; P < 0.05), and the postoperative prosthesis subsidence in the modular group (averaged 0.92 mm; 0–10.2 mm) was significantly less than that in the nonmodular group (averaged 2.20 mm; 0–14.7 mm; P < 0.05). Both modular and nonmodular tapered fluted titanium stems can achieve satisfactory mid-term clinical and imaging results in patients who underwent femoral revision. The modular stems have good control of lower limb length and low incidence of prosthesis subsidence.

Ji-Hoon Nam,#1 Yong-Gon Koh,#2 Paul Shinil Kim,3 Gihun Kim,4 Yoon Hae Kwak,corresponding author4 and Kyoung-Tak Kangcorresponding author1
Knee

Surgeon-dependent factors such as optimal implant alignment of the tibial component are thought to play a significant role in the outcome following primary total knee arthroplasty (TKA). In addition, tibial component malrotation is associated with pain, stiffness, and altered patellofemoral kinematics in TKA. However, measuring tibial component rotation after TKA is difficult. Therefore, the purpose of this study was to find a reliable method for positioning the tibial component in TKA. To investigate the morphology of the tibial plateau, 977 patients’ knees (829 females and 148 males) were evaluated using MRI. The relationships between the femoral transepicondylar axis (TEA), Akagi line, posterior tibial margin (PTM), medial third of the tibial tubercle (MTT), and anatomical tibial axis (ATS) were investigated in this study. In addition, gender difference in tibial rotational alignment were evaluated. Relative to the TEA, the MTT and ATS were externally rotated by 0.5° ± 4.4° and 0.5° ± 5.4°, respectively, while Akagi line and PTM were internally rotated by 3.7° ± 4.5° and 9.9° ± 6.1°, respectively. Gender differences were found in MTT, Akagi line and ATS (P < 0.05). Our result showed that the rotational alignment led to notable variance between femoral and tibial components using fixed bone landmarks. The MTT and ATS axes showed the closest perpendicular aspect with projected TEA. And the MTT and Akagi axes showed the reduced variance. In addition, PTM is not a reliable landmark for rotation of the tibial component. Based on the results of this study, surgeons may choose the proper anteroposterior axis of the tibial component in order to reduce rotational mismatch and improve clinical outcomes.


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