[Learning curve and short-term clinical outcomes of Mako robotic-assisted direct anterior approach total hip arthroplasty]

Objective: To explore the learning curve and short-term clinical outcomes of Mako robotic-assisted direct anterior approach total hip arthroplasty (THA). Methods: The preoperative basic data, surgical information and postoperative rehabilitation of 50 patients who underwent Mako robotic-assisted THA for hip diseases in Department of Orthopedic Surgery of the 6th People's Hospital Affiliated to Shanghai Jiao Tong University from December 2018 to December 2020 were analyzed retrospectively, included operation time, intraoperative blood loss, postoperative complications, postoperative imaging parameters (abduction angle, anteversion angle, lower limb length difference, eccentricity difference) and postoperative hip joint Harris score (hip Harris score, HHS). There were 16 males and 34 females, with a mean age of 50-79(67±10) years. The postoperative clinical results of Mako robotic-assisted total hip arthroplasty was analyzed. A cumulative sum analysis (CUSUM) was performed on the operation time (OT). The CUSUM learning curve was modeled by curve fitting and R² was used to testify the goodness. The different phase of the learning curve was compared with several observation indicators. Results: All patients were followed up for more than 6 months. Two patients had poor wound healing and 5 patients had symptoms of lateral femoral cutaneous nerve injury, which disappeared within 1-2 months. No serious complications such as dislocation, aseptic loosening, periprosthetic infection or revision occurred in all the patients. The average operation time was (81±16) min, and the intraoperative blood loss was (456±84) ml. The average Harris hip score at the last follow-up was 88.6±2.5. The radiological evaluation showed that the positions of the acetabular cups were all in the Lewinnnek safety zone; the limb length discrepancy was (0.15±0.50) cm, the offset was (-0.11±0.72) cm. The OT decreased with the accumulation of the cases. The CUSUM learning curve was best modeled as cubic curve,the fitting curve reached the top at the 19th case. As a cut-off point, the 19th point divided the learing curve into two phases. There were statistical differences in OT, pelvic array installation time, acetabular registration time, acetabular reaming time (all P<0.05), but there was no significant differences in Harris hip score, acetabular prosthesis anteversion angle and abduction angle between the two groups (all P>0.05). Conclusions: The learning curve of Mako robot-assisted DAA-THA is about 19 cases. Mako robot-assisted DAA-THA can ensure the accuracy of prosthetic placement and the safety of the operation during the learning curve, and the short-term clinical results after surgery is excellent.

Morphological analysis and muscle-associated gene expression during different muscle growth phases of Megalobrama amblycephala

Skeletal muscle growth is regulated by both positive and negative factors, such as myogenic regulatory factors (MRFs) and myostatin (MSTN), and involves both hyperplasia and hypertrophy. In the present study, morphological changes during muscle development in Megalobrama amblycephala were characterized and gene expression levels were measured by quantitative real-time polymerase chain reaction (qRT-PCR) analysis in juvenile [60, 90, 120, and 180 days post-hatching (dph)] and adult fish. Our results show that during muscle development, the frequency of muscle fibers with a diameter <20 μm dramatically decreased in both red and white muscles, with a concomitant increase in the frequency of >30 μm fibers in red muscle and >50 μm fibers in white muscle. At 90-120 dph, the ratio of hyperplastic to hypertrophic areas in red and white muscles increased, but later decreased at 120-180 dph. The effect of hypertrophy was significantly larger than hyperplasia during these phases. qRT-PCR indicated MRF and MSTN (MSTNa and MSTNb) genes had similar expression patterns that peaked at 120 dph, with the exception of MSTNa. This new information on the molecular regulation of muscle growth and rapid growth phases will be of value to the cultivation of M. amblycephala.

Development and characterization of novel SSR markers in Siniperca kneri Garman

In this study, 37 transcriptome-derived simple sequence repeat (SSR) markers and 18 genomic SSR markers were developed and characterized in the Chinese perch, Siniperca kneri Garman. The average allele number per locus was 5.1 (range: 2-8) for transcriptome-derived SSRs and 3.8 (range: 2-5) for genomic SSRs. The average observed and expected heterozygosities were 0.666 (range: 0.000-1.000) and 0.692 (range: 0.230-0.857) for transcriptome-derived SSRs, respectively. These values were 0.380 (range: 0.000-1.000) and 0.527 (range: 0.201-0.799) for genomic SSRs, respectively. The average polymorphic information content was 0.638 (range: 0.215-0.824) for transcriptome-derived SSRs and 0.477 (range: 0.183-0.752) for genomic SSRs. Seven of these loci exhibited departure from Hardy-Weinberg equilibrium after sequential Bonferroni's correction for multiple tests, and no significant deviation was observed for the linkage disequilibrium. These developed and characterized markers are anticipated to be useful for studies on population genetics, conservation genetics, and the fishery management of this species.