The Impact of Epinephrine in the Periarticular Injection Cocktail using Ropivacaine for Total Knee Arthroplasty: A Prospective, Randomized, Double-Blind Comparison Study.

BACKGROUND: Epinephrine is used in periarticular injection using ropivacaine to produce a synergistic effect when used with local anesthetic agents but the effect has not been proven yet. The purpose of this study is to evaluate how effective epinephrine is on postoperative clinical outcomes in primary total knee arthroplasty (TKA). METHODS: One hundred sixteen cases (89 patients) who underwent primary TKA were randomized into 2 groups depending on whether epinephrine was mixed. Immediately after the operation, patient-controlled analgesia using fentanyl was initiated. The Numerical Rating Scale, the cumulative dose of fentanyl, active range of motion of the knee joint, and wound complications were evaluated postoperatively. RESULTS: There were no significant differences in mean postoperative Numerical Rating Scale, cumulative dose of fentanyl, and active range of motion between the 2 groups. Neither skin necrosis nor wound dehiscence requiring operative management for skin care was required in either group. CONCLUSION: The use of epinephrine in periarticular injection using ropivacaine after TKA did not have any effect on postoperative acute pain control and opioid usage. THE LEVEL OF EVIDENCE: Therapeutic level I.

Quantitative computed tomography assessment of bone mineral density after 2 years' oral bisphosphonate treatment in postmenopausal osteoarthritis patients who underwent total knee arthroplasty.

OBJECTIVES: To identify the effects of two years' oral bisphosphonate (alendronate) treatment in patients who underwent total knee arthroplasty (TKA); to determine whether significant responses seen after the first year of treatment changed during the second year. Additionally, the study tried to identify factors relating to bone mineral density (BMD) changes. METHODS: This was a prospective 2-year follow-up study of a previous 1-year report of postmenopausal women with knee osteoarthritis who underwent primary unilateral or staged bilateral TKA, after which they received 70 mg alendronate orally once-weekly. BMD was measured using quantitative computed tomography (QCT) on lumbar vertebrae at baseline (pre-TKA) and at 12 and 24 months. Factors associated with BMD changes were determined by regression analysis. RESULTS: Sixty-one patients entered the second year and continued treatment for ≥ 24 months. Mean vertebral QCT BMDs at baseline and after 12 and 24 months' alendronate treatment were 71.8 mg/ml (41.9-97.5 mg/ml), 69.3 mg/ml (31.4-103.9 mg/ml), and 72.7 mg/ml (33.1-136.1 mg/ml), respectively. Patients undergoing bilateral TKA and who had more severe OA at baseline (bilateral severe [grade 4] OA) had a lower BMD response after 2 years' bisphosphonate treatment, compared with patients with less severe unilateral knee OA who underwent unilateral TKA. Improvements were, however, seen compared with year 1 levels. Low BMI was associated with BMD nonresponse. CONCLUSIONS: Patients with bilateral severe OA (grade 4) requiring bilateral knee replacement are at greater risk of nonresponse after 2 years' oral alendronate treatment. A longer duration of treatment may be necessary in these patients.

Revision total knee arthroplasty using a constrained condylar knee prosthesis in conjunction with a posterior stabilized articular polyethylene.

Legacy constrained condylar knee (LCCK) components are designed in the way that they can also be used in conjunction with a posterior-stabilized (PS) polyethylene insert, when adequate collateral stability is present. This study comprised 27 revision total knee arthroplasties (TKA) treated using an LCCK prosthesis and a PS polyethylene insert. Substantial range of motion and Knee Society score improvements were achieved in all subjects. Radiolucent lines between the block-cement were noted in 6 of 27 knees, but not significant. During TKA requiring the use of a femoral augment or stem extension, the design offering least constraint can be chosen, and an LCCK prosthesis with a PS polyethylene insert could be a satisfactory option.

Two-stage reimplantation in infected total knee arthroplasty using a re-sterilized tibial polyethylene insert and femoral component.

Infection in total knee arthroplasty (TKA) is a challenging complication. We reviewed 20 cases of infected TKAs treated by two-stage reimplantation procedure involving the use of a temporary articulating system composed of autoclaved femoral component, low temperature hydrogen peroxide gas plasma sterilized polyethylene insert, and antibiotic-impregnated bone cement. The knee and functional score of the Knee Society scoring system at the last follow (average, 64.8 months) up was 86.2 points and 78.8 points. The success rate in terms of eradication of infection was 95% (19/20 knees). Use of a temporary articulating system composed of the re-sterilized components with antibiotic-impregnated bone cement was an effective therapy not only for the eradication of the infection but also for the recovery of soft tissue health and knee function.

Conservative treatment for the intraoperative detachment of medial collateral ligament from the tibial attachment site during primary total knee arthroplasty.

For intraoperative injuries of the medial collateral ligament (MCL) during primary total knee arthroplasty (TKA), many authors recommended complex reconstructive procedures or conversion to the constrained prosthesis in previous literature. However, it is well known that medial collateral ligament has good healing potential after injuries. This retrospective study evaluated the clinical and radiological results of 15 primary TKAs complicated with intraoperative complete detachment of the MCL from tibial attachment site, which were all treated solely by nonoperative conservative treatment without any other additive procedures or braces. Compared to the MCL-intact contralateral knees, there was no significant difference in terms of clinical and radiological outcome at minimum of 2 postoperative year. There was no case showing clinical instability, either. Solely, the nonoperative conservative treatment for intraoperative injuries of the MCL during primary TKAs is expected not only to be effective with satisfactory results but also to decrease complications derived from other sophisticated reparative or reconstructive procedures.