A Novel Infrapatellar Fat Pad Preservation Technique in Total Knee Arthroplasty Reduced Postoperative Pain and Wound Complications.

OBJECTIVE: The management of the infrapatellar fat pad (IPFP) during total knee arthroplasty (TKA) remains controversial. This study aimed to evaluate a novel IPFP preservation technique-"the medially pedicled IPFP flap"-for reducing postoperative pain, wound complications, and improving functional recovery after TKA. METHODS: A retrospective analysis was conducted on TKA cases at our institution from 2018 to 2021, including those with IPFP preservation (medially pedicled flap) versus IPFP complete resection. Patient demographics, perioperative parameters (blood loss, operative time, length of hospital stay, visual analogue scale [VAS] score, white cell count [WBC], C-reactive protein [CRP], erythrocyte sedimentation rate [ESR], and wound oozing), and postoperative follow-up data (VAS, Knee Society [KSS], or Knee Society functional assessment [KSFA] scores) were compared between groups. Independent sample t-tests were used to compare continuous data and chi-squared tests were used to compare categorical data between groups. RESULTS: Six hundred thirty patients were included, with 278 in the medial pedicled IPFP flap group (preservation group) and 352 in the IPFP resection group (resection group). The operative time was significantly shorter in the preservation versus resection group (125.5 ± 23.2 vs 130.3 ± 28.7 mins, p = 0.03), as was the length of hospital stay (8.4 ± 2.7 vs 9.2 ± 2.3 days, p < 0.01). Regarding pain, the preservation group had significantly lower VAS scores on postoperative day 2 (2.0 ± 0.8 vs 2.4 ± 1.2, p < 0.001) and day 3 (1.5 ± 0.5 vs 1.8 ± 1.0, p < 0.001). CRP and ESR levels on postoperative day 5 were also significantly lower in the preservation group. Wound oozing rates were significantly lower in the preservation versus resection group (0.7% vs 2.8%, p = 0.04). No significant differences existed in VAS, KSS, or KSFA scores at the last follow-up. CONCLUSION: The novel IPFP preservation technique significantly improved surgical exposure, shortened operative time and length of hospital stay. It also reduced wound pain and oozing compared to IPFP resection.

Joint Replacement Surgeries Can Be Safely Performed in HIV Patients.

Whether joint replacement surgery can be performed safely on HIV patients is still a matter of debate. This study aimed to report the surgical efficacy and complications of joint replacement surgery in HIV patients. A total of 21 HIV patients and 27 non-HIV patients who underwent arthroplasties in our hospital were retrospectively reviewed. The 21 HIV patients received 29 joint replacement surgeries including 27 cases of total hip arthroplasty (THA) and 2 cases of total knee arthroplasty (TKA). The non-HIV patients received 16 THA, 10 TKA, and 3 unicompartmental arthroplasty (UKA). The length of hospital stay of HIV patients was significantly lower than that of non-HIV patients. At the last follow-up, there were no significant complications both in the HIV group and the non-HIV groups. No medical staff had any occupational exposure. We concluded that joint replacement surgery in HIV patients is safe and effective. Optimization of patients is key to treatment success. Strictly following the standardized protection protocol can prevent the risk of occupational exposure.

Metagenomic next-generation sequencing assists the diagnosis treatment of fungal osteoarticular infections.

Background: Fungal osteoarticular infection (FOI) is not commonly seen in clinical practice but proposes a great challenge to orthopedic surgeons. In this study, we aimed to investigate the risk factors, the clinical features, and surgical outcomes of FOI in our institution. Specifically, we aimed to explore the role of metagenomic next-generation sequencing (mNGS) in the diagnosis and treatment of FOI. Methods: All the patients who were diagnosed and managed with FOI in our institution from January 2007 to December 2020 were retrospectively reviewed, including primary fungal implant-related infection, primary fungal osteomyelitis or arthritis, and fungal infections secondary to bacterial osteomyelitis or implant-related bacterial infections. The potential risk factors and the clinical and surgical features were analyzed. The pathogen data were compared between culture and the mNGS test. Results: A total of 25 patients were included, namely, 12 primary implant-related infections, 7 primary fungal osteomyelitis or arthritis, and 6 fungal infections secondary to bacterial osteomyelitis or implant-related bacterial infections. Most cases had undergone multiple surgeries or long-term antibiotic treatment. Diagnosis was mainly based on microbial culture and the mNGS test. Optimization of culture methods and the use of mNGS assisted the diagnosis. Specifically, mNGS was performed in 12 patients, 5 of whom were culture-negative. In the remaining seven cases, mNGS demonstrated the same results as culture. Management of FOI was complicated as most patients required multiple surgeries followed by long-term antifungal treatment. In selected cases, antifungal-impregnated cement spacer retention can be an optional choice. The overall success rate was 100% (25/25) for our cohort. Conclusion: We concluded that patients with comorbidities and a history of multiple surgeries or long-term antibiotics are under higher risk for FOI. Use of mNGS assists the diagnosis and treatment of FOI. Surgery combined with long-term antifungal treatment achieved satisfactory outcomes. In selected cases, antifungal-impregnated cement spacer retention can be an optional treatment choice.

Surgical Management for Chronic Destructive Septic Hip Arthritis: Debridement, Antibiotics, and Single-Stage Replacement is as Effective as Two-Stage Arthroplasty.

OBJECTIVE: To compare the surgical outcomes of debridement, antibiotics, and single-stage total hip replacement (DASR) vs two-stage arthroplasty (two-stage arthroplasty) for chronic destructive septic hip arthritis (SHA). METHODS: Cases of chronic destructive SHA treated by DASR or two-stage arthroplasty in our department from January 2008 to October 2021 were retrospectively reviewed. Patient demographic information, perioperative inflammation markers, intraoperative blood loss, microbial culture, and metagenomic new generation sequencing results were recorded. The perioperative complications, hospital stay, hospitalization cost, infection recurrence rate, and Harris Hip Score (HHS) at the last follow-up were compared between the two groups. RESULTS: A total of 28 patients were included in the study, including 11 patients who received DASR and 17 patients who received two-stage arthroplasty. There was no significant difference in demographic information, preoperative serum inflammatory markers, synovial fluid white blood cell count, or percentage of polymorphonuclear leukocytes between the two groups. The DASR group demonstrated significantly lower intraoperative blood loss [(368.2 ± 253.3) mL vs (638.2 ± 170.0) mL, p = 0.002], hospital stay [(22.6 ± 8.1) days vs (43.5 ± 13.2) days, p < 0.0001], and hospitalization expenses [(81,269 ± 11,496) RMB vs (137,524 ± 25,516) RMB, p < 0.0001] than the two-stage arthroplasty group. In the DASR group, one patient had dislocation as a complication. There were no cases with recurrence of infection. In the two-stage arthroplasty group, there was one case complicated with spacer fracture, one case with spacer dislocation, and one case with deep vein thrombosis of the lower limbs. There were no cases with recurrence of infection. There were no significant differences in the readmission rate, complication rate, or HHS at the last follow-up between the two groups. CONCLUSIONS: Both DASR and two-stage arthroplasty achieved a satisfactory infection cure rate and functional recovery for chronic destructive SHA, and DASR demonstrated significantly lower intraoperative blood loss, hospital stay, and hospitalization costs than two-stage arthroplasty. For appropriately indicated patients, if microbial data are available and a standardized debridement protocol is strictly followed, DASR can be a treatment option.

The value of calprotectin in synovial fluid for the diagnosis of chronic prosthetic joint infection.

AIMS: This study aimed to evaluate calprotectin in synovial fluid for diagnosing chronic prosthetic joint infection (PJI) . METHODS: A total of 63 patients who were suspected of PJI were enrolled. The synovial fluid calprotectin was tested by an enzyme-linked immunosorbent assay (ELISA). Laboratory test data, such as ESR, CRP, synovial fluid white blood cells (SF-WBCs), and synovial fluid polymorphonuclear cells (SF-PMNs), were documented. Chi-squared tests were used to compare the sensitivity and specificity of calprotectin and laboratory tests. The area under the curve (AUC) of the receiver operating characteristic (ROC) curve was calculated to determine diagnostic efficacy. RESULTS: The median calprotectin level was 776 µg/ml (interquartile range (IQR) 536.5 to 1132) in the PJI group and 54.5 µg/ml (IQR, 38.75 to 78.25) in the aseptic failure (AF) group (p < 0.05). Using a threshold of 173 ug/ml, the sensitivity was 95.2%, with a 97.6% specificity, and the AUC was 0.993. The sensitivity of calprotectin of the antibiotic-treated PJI group was 100% versus 90.9% of the non-antibiotic-treated PJI group. Although 47.6% (ten cases) of the patients in the PJI group received antibiotics before aspiration, the diagnostic efficacy of calprotectin was not affected. The sensitivity and specificity of ESR, CRP, SF-WBCs, and SF-PMNs ranged from 76.2% to 90.5% and 64.3% to 85.7%, respectively. CONCLUSION: Calprotectin in synovial fluid has great diagnostic efficacy for PJI diagnosisand outperformed ESR, CRP, SF-WBCs, and SF-PMNs.Cite this article: Bone Joint Res 2020;9(8):450-457.

Debridement, Antibiotics, and Implant Retention for Acute Periprosthetic Joint Infection.

OBJECTIVE: To report on our clinical outcomes and on the experience of managing acute periprosthetic joint infection (PJI) with debridement, antibiotics, and implant retention (DAIR). METHODS: We performed a retrospective review of all patients who were diagnosed with acute PJI after primary hip or knee replacement surgeries and who were managed with DAIR in our prospective joint replacement registry from 2008 to 2019. The diagnosis of PJI was made according to the 2011 Musculoskeletal Infection Society (MSIS) criteria. The symptom onset duration, inflammatory marker levels (i.e. C-reactive protein [CRP], erythrocyte sedimentation rate [ESR], white cell count [WBC], and synovial WBC count), functional scores including the Knee Society Score (KSS), the KSS functional score and the Harris Hip Score (HHS), bacteriology, and surgical outcomes of the patients were tracked and recorded. A paired sample of joint fluid and tissues was also sent for a metagenomic next-generation sequencing (mNGS) test. A paired-samples t-test was used to compare the differences in the inflammatory markers and functional scores before and after surgery. RESULTS: A total of 24 patients with 7 infections after hip replacements and 17 infections after knee replacements were included. A total of 21 patients exhibited early postoperative infections, and 3 exhibited late acute hematogenous infections. During a mean follow-up time of 29.2 ± 15.1 months, 22 patients were successfully treated, whereas 2 patients were unsuccessfully treated and required repeated DAIR. The overall success rate of DAIR was 91.7%. For staphylococcal infections, DAIR had a 100% success rate. Five patients who presented with symptoms between 4 and 8 weeks also achieved a 100% success rate. At the last follow-up, the mean CRP level decreased from 52.6 ± 34.0 to 5.4 ± 3.5 (P < 0.001), and the mean ESR level decreased from 72.3 ± 34.3 to 20.2 ± 12.1 (P < 0.001). The mean KSS score increased from 44.8 ± 12.2 to 81.4 ± 9.2 (P < 0.001), and the mean KSS functional score increased from 38.1 ± 3.5 to 73.9 ± 23.0 (P < 0.001), and the mean HHS score increased from 34.4 ± 6.9 to 84.1 ± 15.1 (P < 0.001). The overall pathogen identification rate was 91.7% (22/24 cases). The success rates for Staphylococcus, Streptococcus, and the other pathogens were 100% (9/9 cases), 71.4% (5/7 cases), and 100% (6/6 cases), respectively. CONCLUSION: Debridement, antibiotics, and implant retention has a high success rate for the treatment of acute PJI and may be performed in selected patients whose symptoms have been sustained for over 4 weeks. A high rate of success for staphylococcal infections was reported with the use of DAIR.

[ANTIBIOTIC-IMPREGNATED ARTICULAR CEMENT SPACER FOR TREATMENT OF PERIPROSTHETIC JOINT INFECTION].

OBJECTIVE: To investigate the current problems and corresponding solutions regarding the use of antibiotic-impregnated cement spacer for the treatment of periprosthetic joint infection (PJI). METHODS: A retrospective analysis was made on the clinical data of 27 patients with PJI who underwent two-stage revision with antibiotic-impregnated cement spacer between January 2001 and January 2013. There were 12 males and 15 females, with an average age of 62.7 years (range, 25-81 years). All arthroplasties were unilateral, including 19 hip PJI and 8 knee PJI. The mean duration from primary arthroplasty to PJI was 25 months (range, 3-252 months). After infection was controlled with the antibiotic-impregnated cement spacer combined with systematic antibiotics treatment, two-stage revision was performed. The effectiveness was evaluated. Results One patient died of myocardial infarction at 2 days after surgery. Infection was controlled, and two-stage revision was successfully performed in 19 patients; deep venous thrombosis occurred in 1 of 3 patients who experienced hip spacer fractures, which was cured after conservative management. The spacers were removed and bacteria-sensitive antibiotics was used because of recurrent infections after the first-stage surgery in 7 patients; 3 patients gave up treatment because infection was not controlled, 4 patients received revision after infection was controlled. Twenty-three patients were followed up 1-5 years (mean, 2.3 years). The average Harris hip score and KSS score at 1 years after revision were significantly improved when compared with preoperative ones (P<0.05). In the 8 patients with gram-negative or fungus infection, 7 were found to have recurrent infection after the first-stage surgery; in the 12 patients with gram-positive infection, no recurrent infection was found. Failed treatment was observed in 1 patient with gram-positive and gram-negative infections and 2 with fungus infection, respectively. CONCLUSION: Antibiotic- impregnated cement spacer has a satisfactory effectiveness for PJI. However, complication of spacer fracture should be noted, especially hip spacers. If the pathogen is gram-negative bacteria or fungus, the implanted spacer may increase the possibility of recurrent infection.

[A PROSPECTIVE RANDOMIZED SELF-CONTROLLED STUDY ON EFFECT OF TRANEXAMIC ACID IN REDUCING BLOOD LOSS IN TOTAL KNEE ARTHROPLASTY].

OBJECTIVE: To investigate the safety and efficiency of intravenous tranexamic acid (TXA) to reduce blood loss in total knee arthroplasty (TKA). METHODS: A prospective, randomized, self-controlled study was carried out on 60 patients scheduled for bilateral TKA between January 2012 and December 2013. TXA (10 mg/kg) was injected intravenously approximately 10 minutes before tourniquet release when TKA was performed on one side (TXA group), and TXA was not used on the other side (control group). No significant difference was found in the preoperative hemoglobin (Hgb), platelet (PLT) count, prothrombin time (PT), and activated partial thromboplastin time (APTT) between 2 groups (P > 0.05). The amount of drainage, the total blood loss, the hidden blood loss, the postoperative Hgb, the amount of blood transfusion, the ratio of blood transfusion, and the incidence of vein thrombosis embolism (VTE) were compared between 2 groups. RESULTS: The amount of drainage and total blood loss were significantly less in the TXA group than in control group (P < 0.05), and the Hgb was significantly lower in the control group than in the TXA group at 6 hours, 1, 3, and 7 days after operation (P < 0.05). There was no significant difference in the hidden blood loss between 2 groups (t = 1.157, P = 0.252). The ratio of blood transfusion was significantly less in TXA group (6.7%, 4/60) than in control group (21.7%, 13/60)(P = 0.034). The total amount of blood transfusion was 14 units in TXA group, which was significantly less than that of control group (38 units) (P = 0.004). Deep vein thrombosis occurred in 3 cases in 2 groups respectively, showing no significant difference (P = 1.000). There was no symptomatic pulmonary embolism. All patients were followed up for 8-17 months, with an average of 13.7 months. No new VTE case was found during the follow-up period. CONCLUSION: Intravenous injection of TXA (10 mg/kg) at 10 minutes before tourniquet release in TKA is effective in reducing perioperative blood loss, amount of blood transfusion, and ratio of transfusion, and it will not increase the risk of VTE.

[Total hip arthroplasty for treatment of Crowe type IV congenital dysplasia of hip with dislocation in adults].

OBJECTIVE: To study the effectiveness and acetabular prosthesis selection of the total hip arthroplasty (THA) for Crowe type IV congenital dysplasia of the hip with dislocation in adults. METHODS: Between June 2008 and May 2012, 8 adult patients (8 hips) with Crowe type IV congenital dysplasia of the hip with dislocation underwent THA. They were all female, aged 20-35 years with a mean age of 25 years. The left hip was involved in 5 cases and the right hip in 3 cases. The Harris score of involved hip was 53.9 +/- 6.6. The shortened length of involved extremity was 4-6 cm (mean, 4.8 cm). The X-ray films showed complete dislocation in all cases. The acetabular prosthesis with diameter of 42-44 mm and S-ROM femoral prosthesis were used in THA. RESULTS: The incisions healed by first intention. There was no hip dislocation events and sciatic nerve injury during the follow-up. Femoral nerve injury occurred in 1 case and asymptomatic venous thrombosis of the leg muscle occurred in 2 cases. All the patients were followed up 1-5 years (mean, 3 years). All cases showed obvious improvement of claudication and could restore to work. At 6 months after operation, the mean length difference between affected and contralateral extremities was 0.4 cm (range, 1.0-0.6 cm); the Harris score was significantly increased to 87.6 +/- 0.3 (t = 1.77, P = 0.00). The X-ray films showed that all cases got bony union at 3-6 months after operation and stable interface between acetabular prosthesis and bone. No revision was involved during the follow-up. CONCLUSION: THA with small acetabular cup and subtrochanteric osteotomy is an effective method in the treatment of Crowe type IV congenital dysplasia of the hip with dislocation in adults. The early effectiveness is satisfactory. The long-term survival rate of prosthesis needs to be followed up.

[Extra-large uncemented acetabular components for hip revision].

OBJECTIVE: To investigate the early-term effectiveness of extra-large uncemented acetabular components for hip revision in the treatment of extensive acetabular bone defect. METHODS: Between September 2008 and May 2012, 13 patients (13 hips) with extensive acetabular bone defect underwent first hip revision using extra-large uncemented acetabular components (Jumbo cup). The diameter of Jumbo cup was larger than or equal to 64 mm for male and 60 mm for female. There were 4 males and 9 females with an average age of 64.7 years (range, 58-84 years). The period from primary arthroplasty to revision was 3-16 years (mean, 9.6 years). According to Paprosky classification, acetabular bone defect was rated as stage IIA in 2 cases, as stage IIB in 5 cases, as stage IIC in 4 cases, and as stage IIIA in 2 cases. The preoperative vertical distance from the center of involved femoral head to interteardrop line was (21.2 +/- 6.1) mm longer than that of normal side. The Harris score and the rotation center of hip were evaluated preoperatively and postoperatively. RESULTS: Healing of incision by first intention was obtained in all patients, and no complication of dislocation, infection, and injury of sciatic nerve or femoral nerve occurred. The duration of follow-up ranged from 13 to 40 months (mean, 23.5 months). Partial or complete pain relief was achieved in all patients. The other patients could walk independently and restored to their routine jobs except for 1 case of hemiplegia caused by acute cerebral infarction at 3 months after surgery. In 5 patients with bone implantation, with the prolonging follow-up, the allograft could integrate with the host bone without absorption, and the bone fusion time was 9-35 months (mean, 14.5 months). At last follow-up, the X-ray films revealed that the vertical distance from the center of involved femoral head to interteardrop line was (6.0 +/- 3.1) mm longer than that of normal side, which was significantly reduced when compared with preoperative value (t=11.13, P=0.00). No periprosthetic transparent region, prosthesis displacement, or screw breakage occurred. The Harris score was significantly increased from 30.4 +/- 8.8 preoperatively to 85.1 +/- 3.2 at last follow-up (t-22.11, P=0.00). CONCLUSION: The application of extra-large uncemented acetabular components could be an effective technique for the reconstruction of extensive acetabular bone defect, and gain a good early-term effectiveness. The long-term survival rate of prostheses needs to be followed up.