[Revision total hip arthroplasty using a cementless prosthesis].

OBJECTIVE: To assess the operative technique and results with the usage of cementless prosthesis in hip revision. METHODS: Retrospective study was done on revision of total hip arthroplasty with cementless prosthesis in 72 patients (41 males and 31 females) with an average age of 65.7 years (28-82 years) from January 2004 to December 2009. The reason for revision was 2 infection, 54 aseptic loosening, 4 periprosthetic fractures, 5 fracture of femoral stems and 7 cases of acetabular abrasion after hemi-arthroplasty. The operation time, bleeding loss, complications of infection, dislocation, periprosthetic fractures and loosening were evaluated. The Harris score were used for hip function evaluation. RESULTS: The average operation time was (146±47) minutes (70-280 minutes) and bleeding loss during the operation was (970±540) ml (200-2500 ml). Bacterium cultivation during operation demonstrated infection in 2 patients. Bone windows at the lateral femoral were opened in 4 patients and extend trochanteric osteotomy was done in 7 patients. Fracture of the proximal femur occurred in 8 cases. Twenty-nine patients were treated with bone graft including 18 autografts and 11 allografts. Sixty-seven patients were followed up for an average time of 66 months (20-92 months). Additional revisions were performed in 3 cases including 2 dislocations and 1 infection. There were no death, no damage of major blood vessels and nerves. The bone graft healed during 3-5 months. The survival rates of the femoral prosthesis and the acetabulum prostheses were 95.5% and 98.4%. The mean Harris score was 86±8 (55-95 points). Osteolysis were seen in 13 hips but migration was seen in only 1 patient. CONCLUSIONS: The cementless prosthesis is useful in revision total hip arthroplasty and the perfect clinical results are related to the reliable primary fixation.

One-year mortality in displaced intracapsular hip fractures and associated risk: a report of Chinese-based fragility fracture registry.

BACKGROUND: The purpose of this registry-based retrospective study was to investigate the risk factors related to one-year mortality in displaced intracapsular fragility hip fracture patients. METHODS: Patients were screened from the Fragility Fracture Registry. Inclusion criterion was displaced intracapsular hip fracture patients with atypical or pathological fractures excluded. One-year mortality was investigated against risk factors including age, gender, past medical history, pre-fracture mobility (PFM), pre-operation ASA grade, delayed surgery over 48 h, post-surgical complications, and length of stay at acute orthopedic ward (LOS). RESULTS: A total of 1050 patients were included for further analysis. Gross one-year mortality was 14.9%. One-year mortality was significantly higher in patients who received non-operative treatment and those who received surgery but delayed over 48 h after admission (both p <  0.001). Male gender (OR = 2.708), advanced age (OR = 1.359), higher risk ASA grades (III to V) (OR = 1.990), past history of gastrointestinal disease (OR = 1.671), and renal impairment (OR = 1.984) were related to higher one-year mortality. The mortality of patients in PFM grade 3 and LOS group 3 was significantly higher (OR = 2.240 and 1.722, respectively). CONCLUSIONS: Higher age, male gender, past gastrointestinal disease and renal impairment, ASA grade over 3, indoor confined pre-fracture ambulatory, and stay at hospital over 15 days were risk factors related to higher one-year mortality in surgically treated displaced intracapsular hip fracture patients. A multi-disciplinary approach is advised to patients identified with these risks factors and co-managed by orthopedic surgeons, geriatricians, and fracture liaison nurses.

Effect of Low-Magnitude, High-Frequency Vibration Treatment on Retardation of Sarcopenia: Senescence-Accelerated Mouse-P8 Model.

Sarcopenia-related falls and fall-related injuries in community-dwelling elderly people garnered more and more interest in recent years. Low-magnitude high-frequency vibration (LMHFV) was proven beneficial to musculoskeletal system and recommended for sarcopenia treatment. This study aimed to evaluate the effects of LMHFV on the sarcopenic animals and explore the mechanism of the stimulatory effects. Senescence-accelerated mouse P8 (SAMP8) mice at month 6 were randomized into control (Ctrl) and vibration (Vib) groups and the mice in the Vib group were given LMHFV (0.3 g, 20 min/day, 5 days/week) treatment. At months 0, 1, 2, 3, and 4 post-treatment, muscle mass, structure, and function were assessed. The potential proliferation capacity of the muscle was also evaluated by investigating satellite cells (SCs) pool and serum myostatin expression. At late stage, the mice in the Vib group showed higher muscle strength (month 4, p = 0.028). Generally, contractibility was significantly improved by LMHFV (contraction time [CT], p = 0.000; half-relaxation time [RT50], p = 0.000). Enlarged cross-sectional area of fiber type IIA was observed in the Vib group when compared with Ctrl group (p = 0.000). No significant difference of muscle mass was observed. The promotive effect of LMHFV on myoregeneration was reflected by suppressed SC pool reduction (month 3, p = 0.000; month 4, p = 0.000) and low myostatin expression (p = 0.052). LMHFV significantly improved the structural and functional outcomes of the skeletal muscle, hence retarding the progress of sarcopenia in SAMP8. It would be a good recommendation for prevention of the diseases related to skeletal muscle atrophy.

Muscle mass, structural and functional investigations of senescence-accelerated mouse P8 (SAMP8).

Sarcopenia is an age-related systemic syndrome with progressive deterioration in skeletal muscle functions and loss in mass. Although the senescence-accelerated mouse P8 (SAMP8) was reported valid for muscular ageing research, there was no report on the details such as sarcopenia onset time. Therefore, this study was to investigate the change of muscle mass, structure and functions during the development of sarcopenia. Besides the average life span, muscle mass, structural and functional measurements were also studied. Male SAMP8 animals were examined at month 6, 7, 8, 9, and 10, in which the right gastrocnemius was isolated and tested for ex vivo contractile properties and fatigability while the contralateral one was harvested for muscle fiber cross-sectional area (FCSA) and typing assessments. Results showed that the peak of muscle mass appeared at month 7 and the onset of contractility decline was observed from month 8. Compared with month 8, most of the functional parameters at month 10 decreased significantly. Structurally, muscle fiber type IIA made up the largest proportion of the gastrocnemius, and the fiber size was found to peak at month 8. Based on the altered muscle mass, structural and functional outcomes, it was concluded that the onset of sarcopenia in SAMP8 animals was at month 8. SAMP8 animals at month 8 should be at pre-sarcopenia stage while month 10 at sarcopenia stage. It is confirmed that SAMP8 mouse can be used in sarcopenia research with established time line in this study.