Higher incidence of aseptic loosening caused by a lower canal filling ratio with a modified modular stem in total hip arthroplasty

Purpose: Although a cementless modular prosthesis has shown reliable results, cases of unstable fixation and revision due to aseptic loosening were observed in our institute. The purpose of this study was to clarify the causes of unstable fixation of the prosthesis.Methods: A total of 144 patients (154 hips) who underwent total hip arthroplasty using the modular prosthesis were retrospectively investigated. For the cohort study, 97 patients (104 hips) were included. The femoral component survival rate and sleeve fixation were assessed at a minimum follow-up of 5 years. Patients were divided into 2 groups, including stable and unstable fixation groups,by sleeve fixation. Clinical and radiographic outcomes were compared. Results: The Kaplan-Meier survival rate at 9 years was 93% with revision for any reason as the endpoint in study cohort. The reasons for revision were recurrent dislocation (1 hip) and aseptic loosening of the stem (5 hips). A total of 88 hips (84.6%) showed stable fixation, and 16 hips (15.4%) showed unstable fixation at final follow-up. There was no significant difference in clinical outcomes between the 2 groups at final follow-up. The canal flare index was significantly higher, and the canal filling ratio was significantly lower in the unstable fixation group. Conclusion: Although the modified modular prosthesis was useful for treating anatomically difficult patients, we need to pay attention to both proximal/distal mismatch of the intramedullary canal and the canal filling ratio to achieve stable fixation and good long-term results

Simultaneous medial opening wedge high tibial osteotomy and revision anterior cruciate ligament reconstruction using a bone-patella tendon-bone graft: A case report

It is said that the clinical results of cases with anterior cruciate ligament reconstruction (ACLR) who have knee osteoarthritis (OA) are not very good. A case of simultaneous medial opening wedge high tibial osteotomy (MOWHTO) and revision ACLR using a bone-patella tendon-bone (BPTB) graft for medial knee OA after re-tear of a reconstructed ACL graft is reported. The patient was a 49-year-old man who underwent surgery for a right knee ACL injury by ACLR using an ipsilateral hamstring tendon graft 7 years earlier. He sprained his right knee while he was skiing and injured his reconstructed ACL graft. He had knee instability and pain at the medial side of his knee. X-ray showed a tibia vara deformity and medial knee OA of Kellgren-Lawrence grade II. It was thought that the medial knee pain would remain if he were treated by revision ACLR alone. Therefore, simultaneous MOWHTO and revision ACLR using an ipsilateral BPTB graft were performed. The excellent clinical results and radiological findings 3 years after the operation indicate the usefulness of this approach

High risk of elevated metal concentrations with 9/10-mm stem trunnions and highly cross-linked polyethylene grafted with poly(2-methacryloyloxyethyl phosphorylcholine) in total hip arthroplasty

Background: The risks of metal release due to fretting and corrosion at the head–neck junction and consequent adverse local tissue reaction (ALTR) have concerns in metal-on-polyethylene (MoP) total hip arthroplasty (THA). Although trunnions have become thinner in diameter to increase the range of motion, it has remained unclear whether this change affects metal release and ALTR in vivo. This study aimed to investigate serum metal concentrations and the prevalence of ALTR in MoP THA with a 9/10-mm stem trunnion.Patients and methods: A consecutive series of 37 hips that underwent THA using MoP grafted with poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) with a 9/10-mm trunnion stem were retrospectively reviewed. Serum metal levels were assessed and compared with those in MoP THA with a 10/12-mm trunnion stem. ALTR was diagnosed with serum metal levels and cross-sectional images. The factors associated with serum metal levels were also assessed.Results: The median serum cobalt and chromium levels were 1.5 μg/L and 1.0 μg/L in the 9/10-mm group and 0.2 μg/L and 0.4 μg/L in the 10/12-mm group, respectively. ALTR was found in 5 hips of 3 patients. Revision surgery was performed in 4 hips, and all stem trunnions and femoral heads showed severe corrosion. Postoperative walking ability was associated with serum metal levels.Conclusion: It was found that a 9/10-mm stem trunnion with MoP grafted with PMPC had high risks of metal release in primary THA. Careful follow-up and cross-sectional imaging are needed to detect ALTR for early revision

ランダム化比較試験によるエドキサバン投与下におけるTKA後DVT発生に対するフットポンプの有効性

長崎大学学位論文 [学位記番号]博（医歯薬）甲第986号 [学位授与年月日]平成29年9月20

High risk of elevated metal concentrations with 9/10-mm stem trunnions and highly cross-linked polyethylene grafted with poly(2-methacryloyloxyethyl phosphorylcholine) in total hip arthroplasty

Abstract Background The risks of metal release due to fretting and corrosion at the head–neck junction and consequent adverse local tissue reaction (ALTR) have concerns in metal-on-polyethylene (MoP) total hip arthroplasty (THA). Although trunnions have become thinner in diameter to increase the range of motion, it has remained unclear whether this change affects metal release and ALTR in vivo. This study aimed to investigate serum metal concentrations and the prevalence of ALTR in MoP THA with a 9/10-mm stem trunnion. Patients and methods A consecutive series of 37 hips that underwent THA using MoP grafted with poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) with a 9/10-mm trunnion stem were retrospectively reviewed. Serum metal levels were assessed and compared with those in MoP THA with a 10/12-mm trunnion stem. ALTR was diagnosed with serum metal levels and cross-sectional images. The factors associated with serum metal levels were also assessed. Results The median serum cobalt and chromium levels were 1.5 μg/L and 1.0 μg/L in the 9/10-mm group and 0.2 μg/L and 0.4 μg/L in the 10/12-mm group, respectively. ALTR was found in 5 hips of 3 patients. Revision surgery was performed in 4 hips, and all stem trunnions and femoral heads showed severe corrosion. Postoperative walking ability was associated with serum metal levels. Conclusion It was found that a 9/10-mm stem trunnion with MoP grafted with PMPC had high risks of metal release in primary THA. Careful follow-up and cross-sectional imaging are needed to detect ALTR for early revision

Simultaneous medial opening wedge high tibial osteotomy and revision anterior cruciate ligament reconstruction using a bone-patella tendon-bone graft: A case report

It is said that the clinical results of cases with anterior cruciate ligament reconstruction (ACLR) who have knee osteoarthritis (OA) are not very good. A case of simultaneous medial opening wedge high tibial osteotomy (MOWHTO) and revision ACLR using a bone-patella tendon-bone (BPTB) graft for medial knee OA after re-tear of a reconstructed ACL graft is reported. The patient was a 49-year-old man who underwent surgery for a right knee ACL injury by ACLR using an ipsilateral hamstring tendon graft 7 years earlier. He sprained his right knee while he was skiing and injured his reconstructed ACL graft. He had knee instability and pain at the medial side of his knee. X-ray showed a tibia vara deformity and medial knee OA of Kellgren-Lawrence grade II. It was thought that the medial knee pain would remain if he were treated by revision ACLR alone. Therefore, simultaneous MOWHTO and revision ACLR using an ipsilateral BPTB graft were performed. The excellent clinical results and radiological findings 3 years after the operation indicate the usefulness of this approach

IN VIVO KINEMATICS OF THE ANTERIOR CRUCIATE LIGAMENT DEFICIENT KNEE DURING WIDE-BASED SQUAT USING A 2D/3D REGISTRATION TECHNIQUE

Anterior cruciate ligament (ACL) deficiency increases the risk of early osteoarthritis (OA). Studies of ACL deficient knee kinematics would be important to reveal the disease process and therefore to find mechanisms which would potentially slow OA progression. The purpose of this study was to determine if in vivo kinematics of the anterior cruciate ligament deficient (ACLD) knee during a wide-based squat activity differ from kinematics of the contralateral intact knee. Thirty-three patients with a unilateral ACLD knee consented to participate in this institutional review board approved study with the contralateral intact knee serving as the control. In vivo knee kinematics during the wide-based squat were analyzed using a 2D/3D registration technique utilizing CT-based bone models and lateral fluoroscopy. Comparisons were performed using values between 0 and 100° flexion both in flexion and extension phases of the squat activity. Both the ACLD and intact knees demonstrated increasing tibial internal rotation with knee flexion, and no difference was observed in tibial rotation between the groups. The tibia in the ACLD knee was more anterior than that of the contralateral knees at 0 and 5° flexion in both phases (p < 0.05). Tibiofemoral medial contact points of the ACLD knees were more posterior than that of the contralateral knees at 5, 10 and 15° of knee flexion in the extension phase of the squat activity (p < 0.05). Tibiofemoral lateral contact points of the ACLD knees were more posterior than that of the contralateral knees at 0° flexion in the both phases (p < 0.05). The kinematics of the ACLD and contralateral intact knees were similar during the wide-based squat except at the low flexion angles. Therefore, we conclude the wide-based squat may be recommended for the ACLD knee by avoiding terminal extensio

Double-bundle anterior cruciate ligament reconstruction improves tibial rotational instability: analysis of squatting motion using a 2D/3D registration technique

Background: The anterior cruciate ligament-deficient (ACLD) knee requires appropriate treatment for the patient to return to sports. The purpose of this study was to clarify the kinematics of the anterior cruciate ligament-deficient knee in squatting motion before and after double-bundle anterior cruciate ligament reconstruction (DB-ACLR) using a 2D/3D registration technique. Methods: The subjects of this study were 10 men with confirmed unilateral ACL rupture who underwent DB-ACLR. Computed tomography (CT) of the knee joints was performed before DB-ACLR. Fluoroscopic imaging of the knee motion in squatting before and after DB-ACLR was also performed. The 2D/3D registration technique is a method of calculating positional relationships by projecting the 3D bone model created from the CT data onto the image extracted from the fluoroscopic images. The tibial anteroposterior (AP) and rotational positions were analyzed with reference to the femur. Results: The tibial AP position of the ACLD knees was significantly anterior to the contralateral knees (p = 0.015). The tibial rotational position of the ACLD knees was significantly internally rotated compared to the contralateral knees (p < 0.001). Both tibial AP and rotational positions improved after DB-ACLR (p < 0.001), with no significant differences compared to the contralateral knees. Conclusion: DB-ACLR improved not only tibial AP instability but also tibial rotational instability at knee flexion with weight-bearing. DB-ACLR appears to be a useful technique for normalizing the knee joint kinematics of ACLD knees