Extension contracture stiff knee in haemophilia: Surgical timing and procedure for total knee arthroplasty.

INTRODUCTION: Total knee arthroplasty (TKA) for a stiff knee of patients with haemophilia (PWH) represents a challenge for orthopaedic surgeons for the difficulties of exposing the knee and high complication rate compared to a flexible knee. AIM: To optimize the surgical exposure in primary TKA for PWH and to propose a threshold angle of extension contracture in treating haemophilic knee joints, retrospectively. METHODS: Sixty-seven primary TKAs for PWH (mean age, 48 years) were performed, and incisional approaches to joint were standard (58 cases) and V-Y quadricepsplasty (V-Y) (9 cases). The decision of surgical approach was decided intraoperatively by two surgeons. Pre- and post-knee angles were evaluated in each group. Variables in the V-Y group were evaluated using univariate logistic regression analysis and receiver operating characteristic curve analysis. RESULTS: Univariate logistic regression analysis demonstrated that the preoperative range of motion (ROM) and flexion were significantly associated with V-Y. Threshold values of preoperative flexion and ROM resulting in V-Y using receiver operating characteristic analysis were 45° and 35°, respectively. CONCLUSIONS: Primary TKA for PWH using a standard approach may be performed before the stage preoperative flexion <45° and ROM <35°.

Surgical treatment of haemophilic pseudotumor with severe bone destruction: a case report.

Haemophilia is an X-linked congenital bleeding disorder caused by a deficiency of factor VIII/IX. Patients with haemophilia (PWH) experience spontaneous bleeding into joints and muscles. Recurrent joint bleeds result in painful and disabling haemophilic multi-arthropathy characteristic of elbows, knees and ankles. The standard of care for PWH is replacement of factor concentrate. Haemophilic pseudotumor (HPT) is one of the complications which can occur in PWH due to repeated bleeding. The occurrence of HPT is not uniform, so treatment needs to be tailored to the individual. We report the case of right distal femur HPT with multi haemophilic end-staged arthropathies (bilateral elbows, knees and ankles). He suffered from walking disability and right thigh pain. He showed functional limitations in those arthropathies, so he could not use crutches. To reduce excess loads on affected joints, we performed left total knee arthroplasty before excision of HPT of the right femur. This is the first case report of a 37-year-old man with haemophilia whose treatment combined en bloc excision of the HPT and reconstruction of distal femur using a tumour prosthesis with severe bone destruction after excision of HPT. At the 24-month postoperative follow-up, the patient was able to walk without any support. When the patients suffer from multi-joint haemophilic arthropathy and HPT, comprehensive and well-planned surgical treatment strategy under adequate factor VIII replacement therapy is necessary.

Orthotropic live transplantation for cirrhosis from hepatitis C virus leads to correction of factor IX deficiency allowing for ankle arthroplasty without factor replacement in a patient with moderate haemophilia B.

: Liver transplantation is one of the treatments for haemophilic patients having severe liver cirrhosis who are infected with the hepatitis C virus. Patients with haemophilia can develop arthroplasty requiring surgical intervention, and the surgical outcomes of patients undergoing such procedures after liver transplant has not been reported. Treatment for arthropathy is important for improving the quality of life for patients who survive after liver transplantation. We report the first case of ankle arthroscopic arthrodesis in a patient with haemophilia B after undergoing living donor liver transplantation. We carefully monitored the patient's factor IX (FIX) plasma levels during his perioperative period, and we successfully performed his arthroscopic ankle arthrodesis without administration of any additional FIX concentrates. Our case has demonstrated the feasibility of joint surgery after liver transplantation without administration of additional clotting factors while monitoring FIX activity.

In vitro catalytic activity of N-terminal and C-terminal domains in NukM, the post-translational modification enzyme of nukacin ISK-1.

Lantibiotics are antibacterial peptides containing unique thioether cross-links termed lanthionine and methyllanthionine. NukM, the modifying enzyme of nukacin ISK-1, which is produced by Staphylococcus warneri ISK-1, catalyzes the dehydration of specific Ser/Thr residues in a precursor peptide, followed by conjugative addition of intramolecular Cys to dehydrated residues to generate a cyclic structure. By contrast, the precursor peptide of nisin is modified by 2 enzymes, NisB and NisC, which mediate dehydration and cyclization, respectively. While the C-terminal domain of NukM is homologous to NisC, the N-terminal domain has no homology with other known proteins. We expressed and characterized the N- and C-terminal domains of NukM, NukMN, and NukMC, separately. In vitro reconstitution revealed that full-length NukM fully modified the substrate peptide NukA. NukMN partially phosphorylated, dehydrated, and cyclized NukA. By contrast, NukMC did not catalyze dehydration, phosphorylation, or cyclization reactions. Interaction studies using surface plasmon resonance analysis indicated that NukM and NukMN can bind NukA with high affinity, whereas NukMC has low substrate-recognition activity. These results suggest that NukMN is mainly responsible for substrate recognition and dehydration and that the whole NukM structure, including the C-terminal domain, is required for the complete modification of NukA. To the best of our knowledge, this is the first report providing insights into the in vitro catalytic activity of individual domains of a LanM-type modification enzyme.