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.

Coronal plane stability of cruciate-retaining total knee arthroplasty in valgus gonarthrosis patients: A mid-term evaluation using stress radiographs.

BACKGROUND: Total knee arthroplasty (TKA) using implants with a high level of constraint has generally been recommended for patients with osteoarthritis (OA) who have valgus alignment. However, studies have reported favorable outcomes even with cruciate-retaining (CR) implants. AIM: To evaluate the coronal plane stability of CR-TKA in patients with valgus OA at the mid-term follow-up. METHODS: Patients with primary valgus OA of the knee who underwent TKA from January 2014 to January 2021 were evaluated through stress radiography using a digital stress device with 100 N of force on both the medial and lateral side. Gap openings and degrees of angulation change were determined. Descriptive statistical analysis was performed for both continuous and categorical variables. Inter-rater reliability of the radiographic measurements was evaluated using Cronbach's alpha. RESULTS: This study included 25 patients (28 knees) with a mean preoperative mechanical valgus axis of 11.3 (3.6-27.3) degrees. The mean follow-up duration was 3.4 (1.04-7.4) years. Stress radiographs showed a median varus and valgus gap opening of 1.6 (IQR 0.6-3.0) mm and 1.7 (IQR 1.3-2.3) mm and varus and valgus angulation changes of 2.5 (IQR 1.3-4.8) degrees and 2.3 (IQR 2.0-3.6) degrees, respectively. No clinical signs of instability, implant loosening, or revision due to instability were observed throughout this case series. CONCLUSION: The present study demonstrated that using CR-TKA for patients with valgus OA of the knee promoted excellent coronal plane stability.

Complete Release of the Superficial Medial Collateral Ligament in Total Knee Arthroplasty.

Background: Proper soft-tissue balance was essential in total knee arthroplasty (TKA). Superficial medial collateral ligament (sMCL) release has been recommended in correction of severe varus knee. However, it has concerns of overcorrection. This study aimed to analyze coronal plane laxity in sMCL-released TKA patients. Methods: We prospectively collected data from TKA patients who were operated from January 2015 to November 2018. All patients went through the same surgical steps; however, sMCL was left intact in mild-to-moderate deformity (sMCL-intact), while it was completely released in patients with severe deformity (sMCL-released). All patients went through the same postoperative protocol. We used stress radiograph with 90 N force to evaluate coronal plane laxity and recorded modified Western Ontario and McMaster Universities Osteoarthritis Index score at 3- to 6-year postoperative appointments. Results: There were 46 patients (59 knees) included with an average follow-up time of 48.3 months. The sMCL-intact group consisted of 14 patients (16 knees) with average preoperative mechanical axis (MA) varus of 4.84 degrees exhibited 1.64 mm (0.6-3.6 mm) laxity on medial side and 1.01 mm (0-3.1 mm) on lateral side. The sMCL-released group consisted of 32 patients (43 knees) with average preoperative MA varus of 14.74 degree exhibited 1.96 mm (0.4-4.8 mm) laxity on medial side and 1.57 mm (0.1-5.9 mm) on lateral side. At the time of follow-up, the mean modified Western Ontario and McMaster Universities Osteoarthritis Index in the sMCL-intact and sMCL-released groups were 14.8 and 13.5 (P value .79), respectively. There was no clinical laxity or reoperation of any causes in either groups. Conclusions: Complete release of sMCL in severe varus knee does not result in overcorrection after TKA at the midterm follow-up period. Thus, sMCL release technique could be an effective and safe option for correction of severe varus deformity.

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.

Posterior Cruciate Ligament Resection and Varus Correction in Total Knee Arthroplasty: A Study Using Computer-Assisted Surgery.

BACKGROUND: Alignment correction is crucial for sustaining longevity and function in total knee arthroplasty (TKA). Although the posterior cruciate ligament (PCL) is a secondary stabilizer in the coronal plane, there have been few reports on the effects of PCL resection on varus correction. The study aim was to assess the effect of PCL resection performed using computer-assisted surgery (CAS) on varus correction in TKA. METHODS: From April 2019 through January 2021, patients with varus deformity of <20° and grossly intact PCLs were included. We used CAS to measure varus correction and gap change after PCL resection during CAS-TKA. RESULTS: Twenty-four female and eight male patients (40 operated knees) were included. The mean age was 68.7 ± 9.0 years, and the mean BMI was 26.5 ± 3.7 kg/m2. The mean preoperative mechanical alignment was varus 5.7° ± 2.5°. We found that 1.4° ± 0.6° of varus correction occurred after PCL resection (P < .05). The mean extension and flexion medial-side gap increases were 0.4 mm and 2.0 mm, respectively (P < .05). The mean extension and flexion lateral-side gap increases were 0.4 mm and 1.6 mm, respectively (P < .05). CONCLUSION: PCL resection during TKA resulted in a small degree of varus correction. The flexion gap was larger when the PCL was resected. These effects were predictable, so surgeons should be aware of these findings while performing TKA.

Randomized Double-Blind Controlled Trial Comparing 0.2 mg, 0.1 mg, and No Intrathecal Morphine Combined With Periarticular Injection for Unilateral Total Knee Arthroplasty.

BACKGROUND: The addition of intrathecal morphine (ITM) to neuraxial anesthesia during total knee arthroplasty (TKA) to achieve postoperative analgesia can elicit opioid-related side effects. The other methods of pain alleviation and side effect reduction, including multimodal analgesia, are challenging. This study aimed to determine the efficacy of various ITM dosages for primary unilateral TKA with periarticular injection (PI). METHODS: This randomized double-blind controlled trial was conducted at Vajira Hospital between April 2018 and March 2019. Patients undergoing TKA were randomized into 3 groups: no ITM (M0), ITM 0.1 mg (M1), and ITM 0.2 mg (M2). All patients received PI. Postoperative pain scores, side effects of ITM, and orthopedic outcomes were compared. RESULTS: The trial enrolled 102 patients: M0 (n = 32), M1 (n = 35), and M2 (n = 35). The postoperative pain scores and rescue analgesic consumption of groups M1 and M2 did not differ significantly within the first 24 hours and were significantly lower than those in group M0. Nausea and vomiting were observed more frequently 4 hours postoperatively in M2 than in groups M1 and M0 (77%, 51%, and 6%, respectively; P < .05), which required second-line antiemetic administration (29%, 9%, and 13%, respectively; P = .09). CONCLUSION: Postoperative pain control achieved with PI combined with ITM 0.1 mg after primary unilateral TKA was comparable to that achieved with ITM 0.2 mg. PI without ITM resulted in higher pain scores and rescue analgesic consumption. The frequency and severity of nausea and vomiting 4 hours postoperatively were also lower in patients administered 0.1 mg of ITM than those in patients administered 0.2 mg of ITM.

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.

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).

NF-kappaB p65 involves in reperfusion injury and iNOS gene regulation in skeletal muscle.

This study investigated the effects of inhibition of NF-kappaB activation on microcirculation and inducible NOS expression in reperfused rat cremaster muscle. The muscle from 16 rats underwent 5-h ischemia and 90-min reperfusion. Each rat received NF-kappaB inhibitor pyrrolidine dithiocarbamate (PDTC, 150 mg/kg) or phosphate-buffered saline 15 min before reperfusion. Results showed that PDTC treatment had a significant overall increase in muscle blood flow during reperfusion. Blood flow more rapidly recovered to and over baseline in the PDTC-treated group than in controls, with a significant difference at 10-30 min and 70-90 min. Expression of iNOS mRNA had a 167-fold increase from normal in controls, but was significantly (P < 0.05) reduced to a 63-fold increase in PDTC-treated muscles. In addition, PDTC treatment significantly (P < 0.05) decreased a reperfusion-induced increase in activated NF-kappaB p65 and nuclear p65 protein. Our results suggest that NF-kappaB is involved in I/R injury and that inhibition of NF-kappaB p65 activation affords protection against I/R injury, perhaps via downregulating expression of iNOS transcription.