Objective:To evaluate the diagnostic values of serum fibrinogen and D-dimer for periprosthetic joint infection (PJI).Methods:The medical records were retrospectively analyzed of the 175 patients who had undergone hip or knee revisions at Department of Joint Surgery, Affiliated Hospital to Qingdao University from August 2013 to June 2019. Of them, 59 were diagnosed as PJI (31 knees and 28 hips), including 33 males and 26 females with an age of (67.4±11.7) years and a body mass index (BMI) of (26.1±3.6) kg/m 2 while 116 as aseptic loosening (AL) (19 knees and 97 hips), including 67 males and 49 females with an age of (70.3±8.9) years and a BMI of (25.0±3.6) kg/m 2. The plasma levels of C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), fibrinogen and D-dimer in the 2 groups were recorded and analyzed. The receiver operating characteristic curve (ROC) was used to calculate the sensitivity and specificity of each indicator; the diagnostic value for each indicator was calculated according to the area under the curve (AUC). Results:There was no significant difference between the PJI and AL groups in gender, age or BMI ( P>0.05), but there was a significant difference in the joint type ( P<0.05). Compared with the AL group, the PJI group had significantly higher levels of CRP, ESR, fibrinogen and D-dimer ( P<0.05). The AUCs for CRP, ESR, fibrinogen and D-dimer were 0.830, 0.850, 0.848 and 0.664, respectively. By the Youden index, the optimal predictive cutoffs for CRP, ESR, fibrinogen and D-dimer were 8.06 mg/L, 17.60 mm/h, 3.73 g/L and 685.00 ng/mL, giving sensitivities of 79.2%, 85.4%, 81.3% and 64.6% and specificities of 85.7%, 76.2%, 79.8% and 61.9%. Conclusions:The diagnostic value of serum fibrinogen may be high for PJI, similar to that of CRP or ESR. However, D-dimer may be of limited value for diagnosis of PJI.

Objective:To evaluate the curative effect of 3D printing titanium trabecular metal （TTM） acetabular cups in revision of total hip arthroplasty （THA）.Methods:A retrospective case series study was conducted on the clinical data of 24 patients （25 hips） undergoing THA revision in Affiliated Hospital of Qingdao University from May 2016 to September 2019. There were 10 males and 14 females，aged 43-78 years ［（63.0 ± 11.4） years］. According to Paprosky classification，5 patients（5 hips） were classified as type Ⅰ，9 patients （10 hips） as type ⅡA，5 patients （5 hips） as type ⅡB，1 patient （1 hip） as type ⅡC and 4 patients （4 hips） as type ⅢC. All patients used 3D printing TTM cups. Seven patients （7 hips） were combined with 3D printing TTM pads，and 3 patients （3 hips） were combined with structural bone grafts. The visual analogue scale （VAS），Harris score and quality of life Health Survey Scale （SF-36） score were evaluated before operation，3 months after operation，12 months after operation and at the last follow-up. The X-ray film of hip joint was performed to evaluate the upward movement distance of hip center of rotation （HCOR），limb-length discrepancy （LLD） before operation，1 day after operation and at the last follow-up. The position of cups and bone ingrowth were evaluated at the last follow-up. The postoperative complications were observed.Results:All patients were followed up for 14-54 months ［（34.2 ± 9.3）months］. The VAS was （4.0 ± 0.7）points，（2.3 ± 0.8）points and （0.9 ± 0.2）points at postoperative 3 months，12 months and the last follow-up，significantly lower than that preoperatively ［（6.1 ± 1.0）points］ （ P < 0.05）. A statistically significant difference was found in the pairwise comparisons of postoperative VAS at postoperative 3 months，12 months and the last follow-up（ P < 0.05）. The Harris score was （64.6 ± 5.3）points，（80.5 ± 3.7）points，and （90.3 ± 3.6）points at postoperative 3 months，12 months and the last follow-up，significantly higher than that preoperatively ［（38.8 ± 6.2）points］ （ P < 0.05）. A statistically significant difference was found in the pairwise comparisons of postoperative Harris score at postoperative 3 months，12 months and the last follow-up（ P < 0.05）. The SF-36 score was （556.3 ± 21.9）points，（711.6 ± 15.9）points and （752.8 ± 23.0）points at postoperative 3 months，12 months and the last follow-up，significantly higher than that preoperatively ［（326.3 ± 30.7）points］ （ P < 0.05）. A statistically significant difference was found in the pairwise comparisons of postoperative SF-36 score at postoperative 3 months，12 months and the last follow-up（ P < 0.05）. The upward movement distance of HCOR was （13.5 ± 2.6）mm and （13.6 ± 2.6）mm on the first day after operation and at the last follow-up，significantly lower than that preoperatively ［（34.1 ± 3.5）mm］ （ P < 0.05）. The LLD was （6.2 ± 1.8）mm and （5.3 ± 1.5）mm on the first day after operation and at the last follow-up，significantly lower than that preoperatively ［（31.6 ± 5.2）mm］ （ P < 0.05）. All the cups were stable. Good bone ingrowth was found in 23 hips. There was no postoperative complication except for one patient with poor wound healing. Conclusion:For THA revision，the use of 3D printing TTM cups can effectively relieve pain，improve hip function，provide satisfactory biological fixation and and reduce complications.

Objective:To compare the clinical prognosis of modified and traditional knotless suture bridge technique in treatment of rotator cuff tear under shoulder arthroscopy.Methods:A retrospective case-control study was conducted to analyze 60 patients with rotator cuff tear admitted to Affiliated Hospital of Qingdao University from June 2018 to June 2019，including 19 males and 41 females，aged 32-74 years［（59.3±10.1）years］. There were 26 patients on the left side and 34 patients on the right side，with the body mass index（BMI）of 19.5-32.4 kg/m 2［（25.5±2.6）kg/m 2］，rotator cuff tear of 2.0-3.7 cm［（2.7±0.4）cm］and pain duration of 2-88 days［（26.2±17.1）days］. A total of 31 patients were repaired with a modified knotless suture bridge（modified group）and 29 patients with a traditional knotless suture bridge（traditional group）. Comparison was made between the two groups in aspects of range of motion of shoulder flexion，abduction and external rotation，visual analog scale（VAS），University of California Los Angeles（UCLA）should function score，Constant shoulder function score，retear and complications at postoperative 3 and 12 months. Results:All patients were followed up for 9-15 months［（12.0±1.8）months］. Three months after operation，the two groups showed no significant differences in shoulder range of motion of abduction，flexion，external rotation，UCLA shoulder function score or Constant shoulder function score（ P>0.05）；while VAS was（2.7±1.2）points in modified group，significantly lower than（3.4±1.2）points in traditional group（ P<0.05）. Twelve months after operation，the shoulder range of motion of abduction and flexion in modified group was（146.9±21.4）° and（150.4±16.2）°，significantly higher than that in traditional group［（130.7±27.4）°，（140.6±18.4）°］（ P<0.05）；There was no significant difference in external rotation activity between the two groups（ P>0.05）；VAS，UCLA shoulder function score and Constant shoulder function score［（1.2±0.5）points，（29.5±2.3）points，（80.4±5.4）points，respectively］in modified group were significantly higher than those in traditional group［（1.5±0.5）points，（27.2±2.7）points，（76.3±6.6）points，respectively］（ P<0.05）. Three months after operation，there was no significant difference in the classification of Sugaya between the two groups（ P>0.05）. Twelve months after operation，the classification of Sugaya was significantly different between the two groups（ P<0.05），with no retear in modified group but 3 patients with retear in traditional group. No postoperative complications occurred，such as non-healing，infection or persistent swelling. Conclusion:For patients with rotator cuff tear，the modified knotless suture bridge technique under shoulder arthroscopy has better range of motion and function，more obvious pain relief and a lower rate of retear than the traditional technique.