Debridement, antibiotics, and implant retention combined with direct intra-articular antibiotic infusion in patients with acute hematogenous periprosthetic joint infection of the knee.

BACKGROUND: Debridement, antibiotics, and implant retention (DAIR) is the recommended treatment for acute hematogenous periprosthetic joint infection (PJI) after total knee arthroplasty (TKA). However, DAIR is associated with a high percentage of unsuccessful outcomes. Since 2007, direct intra-articular antibiotic infusion, which can provide a high concentration of intra-articular antibiotic, has been used in combination with DAIR to improve treatment outcomes among patients in our institution. This study aimed to assess the outcomes of DAIR combined with direct intra-articular antibiotic infusion in patients who presented with acute hematogenous PJI after TKA. METHODS: We reviewed the data of all patients diagnosed with acute hematogenous PJI after primary TKA (from 2008 to 2015) who received DAIR combined with direct intra-articular antibiotic infusion. RESULTS: In total, 15 knees in 12 patients were semi-urgently treated with this method. The mean follow-up time was 93.3 (minimum: 56) months, and the longest follow-up time was 11 years. Two patients (n = 3 knees) had a well-functioning, non-infected prosthesis 6 and 10 years after the procedure. Two patients (n = 2 knees) had re-infection 2 and 5 years after surgery, and they required two-stage revision. None of the patients were lost to follow-up. Finally, 13 (86.6%) of 15 infected knees were successfully treated with this method. CONCLUSIONS: DAIR combined with direct intra-articular antibiotic infusion is an effective treatment for acute hematogenous PJI after TKA.

Relationship of plasma and synovial fluid vascular endothelial growth factor with radiographic severity in primary knee osteoarthritis.

PURPOSE: Recent evidence suggests that angiogenesis and inflammation contribute to the development and progression of osteoarthritis (OA). The purpose of this study was to investigate vascular endothelial growth factor (VEGF) levels in plasma and synovial fluid of patients with knee OA and to determine the relationship of VEGF levels with disease severity in knee OA. METHODS: A total of 100 subjects were enrolled in this study (80 knee OA patients and 20 healthy controls). Plasma and synovial fluid VEGF levels were analysed using enzyme-linked immunosorbent assay. VEGF expressions in synovial membrane and articular cartilage samples were assessed using immunohistochemistry. RESULTS: VEGF level in synovial fluid of knee OA patients was tenfold higher than that in paired plasma (P < 0.001). Both plasma and synovial fluid VEGF exhibited a positive correlation with radiographic severity (r = 0.454 and r = 0.727, P < 0.001, respectively). VEGF expression was highly detectable in synovial lining cells and articular chondrocytes of knee OA patients. CONCLUSIONS: VEGF levels in both plasma and synovial fluid were positively correlated with the severity of knee OA. Therefore, VEGF may be useful for monitoring OA severity and could play a substantial role in the development and progression of knee OA.

Computer assisted surgery evaluation of femoral component rotation in well-balanced and well-aligned total knee arthroplasty using gap technique.

OBJECTIVE: Using computer assisted surgery (CAS) to assess femoral component rotation in well-balanced, well-aligned total knee arthroplasty (TKA) implanted with Posterior Cruciate Ligament (PCL) excision type prosthesis using gap technique. MATERIAL AND METHOD: Using CAS, well-balanced TKA was defined by both flexion/extension and medial/lateral gap difference of less than 2 mm and well-aligned TKA was defined by final mechanical axis within +/- 3 degrees deviation and flexion contracture of less than 5 degrees without hyper extension. Femoral component rotation was determined by posterior condylar axis versus proximal tibia resection plane. The present study analyzed data from January 1, 2009 to September 30, 2009. RESULTS: Out of 65 knees, 34 knees (14 fixed and 20 mobile bearing prosthesis) were considered well-balanced and well-aligned. Mean femoral component rotation was 2.12 +/- 3.38 degrees. Seven knees were within 2-4 degrees external rotation. There was no statistically significant difference of femoral component rotation between fixed and mobile bearing. CONCLUSION: Wide range of femoral component rotation occurred in well-aligned and well-balanced TKA using PCL excision type prosthesis.

Results of peri-articular steroid injection in the treatment of chronic extra-articular pain after total knee arthroplasty.

OBJECTIVE: The authors conducted study to analyze results of peri-articular steroid injection in the treatment of chronic pain from soft tissue inflammation after total knee arthroplasty (TKA). MATERIAL AND METHOD: The authors retrieved data from all patients underwent TKA whom suffered with chronic extra-articular pain and received local peri-articular steroid injection by 2 senior authors during January 1, 2008 to June 30, 2010. Clinical evaluation such as pain score, knee score and functional score were recorded pre-injection and three months after injection. RESULTS: 554 TKA cases were operated during January 1, 2008 and June 30, 2010. 29 knees from 28 female patients were injected with steroid injection and included in the present study. Mean age of 64.7 year and mean BMI of 27.7. Three patients in this group were diagnoses as Diabetes. The most common site of injection was in Tibia, with either Anserinus bursa or around Gerdy's tubercle. Mean time to injection after operation was 5 months. Mean VAS was reduced from 56.5 +/- 20.32 to 20.57 +/- 16.1. Mean knee score and functional score were improved from 74.62 +/- 14.24 to 85.71 +/- 11.85 and from 53.4 +/- 22.57 to 67.04 +/- 21.17 consecutively. All clinical difference has statistically significant with p-value < 0.05. There was no incident of superficial or deep infection at mean follow-up time of 2 years and 5 months. CONCLUSION: Local steroid injection is a safe and effective choice for treatment of pain from chronic soft tissue inflammation after TKA.

Effects of posterior cruciate ligament resection in total knee arthroplasty using computer assisted surgery.

OBJECTIVE: The authors prospectively measure the effects of Posterior Cruciate Ligament (PCL) excision in Total Knee Arthroplasty (TKA) using Computer Assisted Surgery (CAS). MATERIAL AND METHOD: Between April 2008 and June 2008, sixteen knees of fifteen patients with varus deformity less than 20 degree and grossly intact PCL were included in this study. Using CAS and tensioning device to maintain consistent pressure, extension and flexion gap on both medial and lateral side before and after resection of PCL was recorded. RESULTS: The mean increases of extension gap on medial and lateral side after resection of PCL are 0.17 +/- 0.22 mm (-0.17 to 0.5 mm) and 0.25 +/- 0.37 mm (-0.33 to 1.16 mm) respectively. The mean increases of flexion gap on medial and lateral side are 1.29 +/- 1.02 mm (0-3 mm) and 2.09 +/- 1.12 (0.5-4.66 mm) respectively. CONCLUSION: Resection of PCL showed increase of flexion gap more than extension gap (p-value < 0.05) and lateral side of flexion gap always increase more than medial side (p-value < 0.05).

A comparison of early clinical outcome in computer assisted surgery and conventional technique in minimally invasive total knee arthroplasty.

OBJECTIVE: To compare the clinical outcomes of minimally invasive total knee arthroplasty (MIS TKA) with and without computer assisted surgery (CAS). MATERIAL AND METHOD: From September 2007 to February 2008, 64 patients (70 knees) underwent MIS TKA were included. Clinical data such as operative time, pain score, total blood loss and Radiographic data were recorded and compared. RESULTS: There were no significant different in clinical outcome of both groups but range of motion of MIS group was better than CAS group. However, the percentage of outlier of bone cut in CAS group was 6.5% on both femur and tibia while percentage of outlier in MIS group was 16.6% on femur and 25% on tibia. DISCUSSION: Combining CAS with MIS TKA showed improvement of accuracy in coronal bone cut without increase of operative time or complications. The difference of ROM may be due to different prosthesis design in each group.

Percutaneous versus open bone grafting in the treatment of tibial fractures: a randomized prospective trial.

PURPOSE: To compare the results between percutaneous bone grafting and open bone grafting of tibial shaft fractures. METHOD: Thirty tibial fractured shafts with a delayed union or a high-energy tibial fractures which required early prophylaxis bone grafts were randomized to either percutaneous bone graft (n= 15) or open bone graft (n=15). One patient from the open bone graft group was lost to follow-up. Characteristics of the patients were similar in both groups. RESULTS: The mean length of follow-up was 2.5 years. Percutaneous bone graft technique was associated with significantly less blood loss (p<0.01) and shorter operative time (p<0.01). One patient in the percutaneous group had posterior tibial nerve palsy postoperatively, which recovered completely after 6 weeks. There were no differences in rate of union, healing time of the successful cases, postoperative pain and hospital stay. CONCLUSION: The percutaneous technique has effective results similar to the open technique in promoting union of tibial fractures. It should be considered as a useful alternative to the open bone graft technique.