Objective:To analyze the short-and medium-term clinical outcomes of Mako robotic-assisted posterior-lateral approach in complex primary total hip arthroplasty (THA).Methods:A retrospective case series analysis was conducted on 29 patients with complex hip conditions who underwent Mako robotic-assisted posterior-lateral approach at Department of Orthopaedics, the Second Affiliated Hospital of Zhejiang University School of Medicine from November 2020 to December 2024. The patient cohort included 14 cases of developmental dysplasia of the hip, 8 cases of ankylosed hip, 3 cases of traumatic hip arthritis, 3 cases of sequelae of purulent hip arthritis, and 1 case of synovial chondromatosis. There were 12 males and 17 females, with an age of (62.3±9.4) years (range:44 to 79 years). Surgical time, intraoperative blood loss, vascular and nerve injury, postoperative infection, and other complications were recorded. Preoperative and postoperative lower limb length discrepancy, combined offset difference (ΔCO), acetabular abduction angle, and acetabular anteversion angle were measured. The Harris hip score was recorded at regular follow-ups. Data comparison was conducted using the paired sample t-test. Results:All patients successfully underwent surgery with the Mako robotic system. The surgical time was (107.6±41.5) minutes (range:50 to 235 minutes), and the intraoperative blood loss was (165.5±147.7) ml (range:50 to 800 ml). All patients were followed up for a duration of (27.3±16.7) months (range:3 to 51 months). The planned intraoperative acetabular cup abduction angle was 40.1°±1.6° (range: 36° to 45°), and the measured postoperative acetabular cup abduction angle was 40.2°±3.5° (range: 33° to 54°), with no significant difference ( t=0.231, P=0.819). The planned intraoperative acetabular cup anteversion angle was 19.1°±3.9° (range: 15° to 25°), and the measured postoperative acetabular cup anteversion angle was 18.5°±3.4° (range: 10° to 26°), with no significant difference ( t=1.792, P=0.084). The difference in length of both lower limbs was (-17.6±15.0) mm (range:-50 to 10 mm) before operation and (-1.5±16.0) mm (range:-33 to 53 mm) after operation ( t=6.282, P<0.01)(positive values indicate that the surgical side is longer than the contralateral side). The ΔCO was (4.1±12.0) mm (range:-18 to 30 mm) before operation and (-2.2±13.3) mm (range:-44 to 17 mm) after operation, with statistically significant difference ( t=2.635, P=0.014). One patient experienced vascular injury with embolism postoperatively, while no other complications were observed in the remaining patients. No loosening, dislocation, or fracture of the prosthesis was noted during the follow-up period. The Harris function score was improved from (47.1±8.3) points(range:15 to 62 points) preoperatively to (73.0±5.5) points(range:57 to 83 points) at the three-month postoperative follow-up ( t=22.630, P<0.01). Conclusion:The use of Mako robotic assistance in complex total hip arthroplasty can enhance the accuracy of prosthesis placement, minimize lower limb length discrepancy, and improve hip joint function.

Objective:To analyze the short-and medium-term clinical outcomes of Mako robotic-assisted posterior-lateral approach in complex primary total hip arthroplasty (THA).Methods:A retrospective case series analysis was conducted on 29 patients with complex hip conditions who underwent Mako robotic-assisted posterior-lateral approach at Department of Orthopaedics, the Second Affiliated Hospital of Zhejiang University School of Medicine from November 2020 to December 2024. The patient cohort included 14 cases of developmental dysplasia of the hip, 8 cases of ankylosed hip, 3 cases of traumatic hip arthritis, 3 cases of sequelae of purulent hip arthritis, and 1 case of synovial chondromatosis. There were 12 males and 17 females, with an age of (62.3±9.4) years (range:44 to 79 years). Surgical time, intraoperative blood loss, vascular and nerve injury, postoperative infection, and other complications were recorded. Preoperative and postoperative lower limb length discrepancy, combined offset difference (ΔCO), acetabular abduction angle, and acetabular anteversion angle were measured. The Harris hip score was recorded at regular follow-ups. Data comparison was conducted using the paired sample t-test. Results:All patients successfully underwent surgery with the Mako robotic system. The surgical time was (107.6±41.5) minutes (range:50 to 235 minutes), and the intraoperative blood loss was (165.5±147.7) ml (range:50 to 800 ml). All patients were followed up for a duration of (27.3±16.7) months (range:3 to 51 months). The planned intraoperative acetabular cup abduction angle was 40.1°±1.6° (range: 36° to 45°), and the measured postoperative acetabular cup abduction angle was 40.2°±3.5° (range: 33° to 54°), with no significant difference ( t=0.231, P=0.819). The planned intraoperative acetabular cup anteversion angle was 19.1°±3.9° (range: 15° to 25°), and the measured postoperative acetabular cup anteversion angle was 18.5°±3.4° (range: 10° to 26°), with no significant difference ( t=1.792, P=0.084). The difference in length of both lower limbs was (-17.6±15.0) mm (range:-50 to 10 mm) before operation and (-1.5±16.0) mm (range:-33 to 53 mm) after operation ( t=6.282, P<0.01)(positive values indicate that the surgical side is longer than the contralateral side). The ΔCO was (4.1±12.0) mm (range:-18 to 30 mm) before operation and (-2.2±13.3) mm (range:-44 to 17 mm) after operation, with statistically significant difference ( t=2.635, P=0.014). One patient experienced vascular injury with embolism postoperatively, while no other complications were observed in the remaining patients. No loosening, dislocation, or fracture of the prosthesis was noted during the follow-up period. The Harris function score was improved from (47.1±8.3) points(range:15 to 62 points) preoperatively to (73.0±5.5) points(range:57 to 83 points) at the three-month postoperative follow-up ( t=22.630, P<0.01). Conclusion:The use of Mako robotic assistance in complex total hip arthroplasty can enhance the accuracy of prosthesis placement, minimize lower limb length discrepancy, and improve hip joint function.

Objective To compare the clinical outcomes of arthroscopy-assisted Tightrope technique and clavicular hook plating for the treatment of acromioclavicular joint dislocation of Rockwood Type Ⅲ in aduhs.Methods The clinical data were reviewed of the 60 patients who had been treated for acromioclavicular joint dislocation of Rockwood Type Ⅲ from January 2012 to December 2015 at Department of Orthopedics,Jinhua Municipal Central Hospital.Their age ranged from 34 to 62 years (mean,40 years).Injury was at the left side in 28 cases and at the right in 32 ones.They were randomly assigned to receive treatment either using arthroscopy-assisted Tightrope technique (group A,30 cases) or using clavicular hook plate (group B,30 cases).The 2 groups were compared in terms of incision length,operation time,blood loss,visual analogue scale (VAS) and Constant-Murley shoulder function scores at postoperative 3 and 12 months.Results The 2 groups were compatible because there were no significant between-group differences in gender,age,injury laterality,Rockwood fracture typing or injury cause (P ＞ 0.05).All the patients were followed up for a mean of 10 months (from 6 to 12 months).Primary incision healing was achieved in both groups with no neural lesion.The incision length in group A (3.4 ± 0.6 cm) was significantly shorter than that in group B (8.8 ± 1.8 cm),and the blood loss in the former (40.0 ± 8.2 mL) significantly less than that in the latter (70.9 ± 9.8 mL) (P ＜ 0.05).The VAS scores and Constant-Murley shoulder function scores at postoperative 3 and 12 months in group A (respectively:2.2±1.1 and 1.1 ±0.9 points;85.5±2.1 and 98.0±3.1points) were significantly better than those in group B (respectively:3.2 ± 1.8 and 2.1 ± 1.2 points;75.0 ±4.1 and 85.1 ±2.9 points) (P ＜ 0.05).There were no obvious complications during the follow-up period in either group.Conclusions Although both arthroscopy-assisted Tightrope technique and clavicular hook plating can relieve shoulder pain in the adult patients with acromioclavicular joint dislocation of Rockwood Type Ⅲ,the former shows advantages of a smaller incision,less bleeding,lower VAS scores,and reduced pain and financial cost for the patients due to no trouble of implant removal.

Objective To investigate the outcomes of the treatments for the patients with Vancouver type B 1 periprosthetic femur fractures.Methods Seventeen patients with periprosthetic femoral fractures (5 males and 12 females;average age,70.4 years,range from 37 to 86 years) who underwent revision arthroplasty or open reduction and internal fixation between December 2006 and June 2016 were retrospectively reviewed.Periprosthetic femoral fractures occurred at the mean time of 65.1 months after arthroplasty.Twelve patients underwent open reduction and internal fixation and five cases underwent total hip or stem revision with Solution from Depuy,Wagner from Zimmer,Echelon from Smith & Nephew or Secur-Fit Max from Stryker due to primary bone loss,acetabular component wear or long-time prosthesis use respectively.Data were collected at 1,3,6 and 12 months and then each year postoperatively.All patients were followed up,and the results of X-ray,postoperative Harris hip score,stability of prosthesis and complications were also evaluated.Results A total of 5 patients underwent revision arthroplasty,and 12 patients underwent open reduction and internal fixation.The mean follow-up duration was 56 months (range from 7 to 120 months).Total blood loss in the open reduction and internal fixation group and in revision group was 385± 129 ml and 531± 113 ml respectively.The operation duration in the open reduction and internal fixation group was 72±36 min while it was 126±48 min in the revision group.The postoperative Harris hip score in the open reduction and internal fixation group was significantly increased compared with preoperative Harris hip score (68.8±18.4 vs.46.2±9.6),as well as in the revision group (75.0±8.9 vs.57.4±13.0).For the incidence of complications,in the open reduction and internal fixation group,one patient suffer with delayed fracture union,one patient complained about persistent pain and one suffered a secondary fracture,while in the revision group one suffered from blood loss and one with long-term pain.Conclusion Open reduction and internal fixation is an optimal intervention for Vancouver B 1 fracture,and revision arthroplasty can be considered as a safe alternative in patients with primary bone loss,implant of short survival time,severe liner wear or long-term prosthesis use.

ObjectiveTo investigate the size effect of hydroxyapatite nanoparticles on proliferation and apoptosis of osteoblast-like cells.MethodsCetyltrimethylammnonium bromide (CTAB) was used to regulate the size of nano hydroxyapatite (nHAP) particles.All obtained particles were characterized by transmission electron microscopy (TEM),X-ray diffraction,dynamic light scattering and chemical analysis.HAP films were obtained by slowly coating cover glasses with 1％ HAP particle suspension.MG-63 cells on three different films(20HAP,40HAP and 80HAP) were cocultured for up to 5 days.Cell proliferation assay was obtained by methyl thiazolyl tetrazolium (MTT).Cell apoptosis was detected by flow cytometric detection.Cell ultrastructure morphology was observed by TEM observation.ResultsnHAP with diameter of 20 nm,40 nm and 80 nm were synthesized and and analyzed.The MG-63 cells were cultured on three different fihns.The optical density value of cells on 20HAP was 1.22±0.13 after 5 days incubation,and there was no different compared to the control group(F=6.843,P=0.124).Cell number and viability were significantly higher on 20HAP compared to large nHAP after 5 days incubation.The percentage of apoptotic cells increased with increasiug nHAP particle size.TEM images showed 20HAP was found in cytoplasm and cell morphology had no changes.ConclusionBoth cell proliferation and cell apoptosis are related to the size of the nHAP particles.20HAP was the most effective on promoting cell growth and inhibiting cell apoptosis.

Objective To investigate the effects of locally and systemically administered alendronate on wear-debris induced osteolysis in vivo. Methods Endotnxin-free titanium particles were injected into rabbit femurs prior to insertion of a non-weight-bearing polymethylmethacrylate plug into the distal femur canal. Then the particles were repeatedly injected into the knee 2, 4 and 6 weeks after the implantation. Alendronate was incorporated into bone cement for local delivery at three different concentrations [0.1, 0.5, and 1.0 weight%(wt%)]. For systemic delivery, alendronate was subcutaneously injected ( 1.0 mg· kg-1·week-1).Results Eight weeks after operation, there was significant evidence of osteolysis surrounding the plug in the control group, while markedly-blocked osteolysis was noted in the local delivery group (0.5 wt% and 1.0 wt%), and the systemic delivery group. It was found that alendronate had improved peri-prosthetic bone mineral density in a dose-effect model. Notably, no significant difference was found between local delivery of 0.5 wt% alendronate and systemic delivery in bone mineral density and implant fixation. Conclusion Alendronate-loaded bone cement (0.5 wt% ) may be as effective as the systemic delivery in inhibiting titanium particle-induced osteolysis.