What's New in Adult Reconstructive Knee Surgery

Sealing the Intramedullary Femoral Canal for Blood Loss in Total Knee Arthroplasty: A Meta-analysis of Randomized Controlled Trials

Blood loss after total knee arthroplasty (TKA) is a potentially serious medical problem since it leads to anemia, increased need for transfusion, and prolonged hospitalization. Some studies have reported that sealing of the intramedullary femoral canal during TKA may decrease postoperative blood loss. The purpose of this study is to determine the effects of sealing of the intramedullary femoral canal during TKA on blood loss and transfusion rate. Electronic databases, PubMed, EMBASE, the Cochrane Library, Web of Science, and Chinese Biomedical Database, were systematically searched. Only randomized controlled trials (RCTs) that compared the sealing group with the control group during TKA were included up to March 2019. Two reviewers independently extracted data and assessed the quality of included studies. The statistical analysis was performed by using Review Manager 5.3 software. Cochrane Risk of Bias tool was used for quality assessment. Overall, eight RCTs involving 996 patients met our criteria and were analyzed. The results of meta-analysis showed that patients in the sealed group had less total blood loss, less total drain output and less hidden blood loss, less transfusion rates, a lower drop of hemoglobin level at day 1 postoperatively, and less hematoma than the control group. On the other hand, there were no significant differences in infection, deep vein thrombosis, and redness of incision between sealed and control group. Current meta-analysis found that sealing the femoral canal during TKA was an effective method for the control of blood loss.

Hyaluronan Injections Show No Histologic Evidence of Adverse Tissue Effects

Background:

The safety of hyaluronan intra-articular injections is mostly based on animal studies and clinical evidence rather than histologic studies from human administration.

Objective:

This study analyzed the histologic effects of viscosupplementation with sodium hyaluronate on the synovium and articular cartilage of human knee specimen status post total knee arthroplasty within 3 years of viscosupplementation.

Methods:

Twenty-four specimens from total knee arthroplasties from April 2012 to August 2016 at NYU Winthrop Hospital were selected for microscopic analysis. All cases had a diagnosis of end-stage osteoarthritis at the time of surgery. Thirteen of the cases had 3 viscosupplementation injections of the knee with Euflexxa, a hyaluronate-based viscosupplementation agent, within 3 years preceding a total knee replacement. The remaining 11 did not receive viscosupplementation and were incorporated as controls. Upon histologic review, synovium was categorized by degree of hyperplasia and inflammation and the presence or absence of foreign material and giant cell reactions. Residual articular cartilage was categorized by staining intensity, and the presence or absence of crystals, foreign material, and giant cell reactions.

Results:

No significant difference was found between these groups for degree of synovial hyperplasia (P = .33) or for cartilage staining density (P = .42). None of the samples displayed evidence of foreign material, crystals, or giant cell reactions.

Conclusion:

In this cohort of patients, we demonstrated that Euflexxa was administered without any discernible microscopic adverse tissue effects.

The effect of unloader knee braces on medial meniscal strain

BACKGROUND:

A medial meniscal tear is a common knee injury, especially following an anterior cruciate ligament injury. Decreasing the compressive force on the medial meniscus during dynamic activities using an unloader knee brace could reduce meniscal strain, effectively reducing injury risk and/or severity.

OBJECTIVES:

To investigate the efficacy of two unloader knee braces on medial meniscus strain during dynamic activities in intact & deficient anterior cruciate ligament states.

STUDY DESIGN:

Combined in vivo/in vitro study.

METHODS:

In vivo knee kinematics and muscle force profiles from a healthy individual performing single/doubleleg squats and walking motions were simulated on 10 cadaveric specimens using a dynamic knee simulator system. Simulations were performed on knees in unbraced and braced scenarios, with and without the anterior cruciate ligament. Anterior and posterior medial meniscal strains were measured.

RESULTS:

Two different braces each showed a significant reduction in the posteromedial meniscal strain ( p ⩽ 0.01) in an intact anterior cruciate ligament state. Neither brace mirrored this result for the anteromedial strain ( p > 0.05). In the deficient anterior cruciate ligament state, the braces had no significant effect on strain ( p > 0.05).

CONCLUSION:

Two unloader knee braces effectively reduced strain in the medial meniscus with an intact anterior cruciate ligament during dynamic activities. Neither brace made a significant reduction in strain for anterior cruciate ligament-deficient knees.

CLINICAL RELEVANCE

Unloader knee braces could be used to reduce the medial meniscus strain following meniscal surgery and during rehabilitation in patients with an isolated medial meniscus injury. However, these braces cannot be recommended for this purpose in patients with an anterior cruciate ligament deficiency.

Early stage periarticular injection during total knee arthroplasty may provide a better postoperative pain relief than late-stage periarticular injection: a randomized-controlled trial

PURPOSE

This study was performed to determine whether periarticular injection performed in the early stage of total knee arthroplasty (TKA) could provide a better postoperative pain relief than periarticular injection performed in the late stage of TKA. The hypothesis was based on the concept that analgesic intervention before the onset of noxious stimuli would be associated with less postoperative pain.

METHODS

A total of 105 participants were randomly assigned to receive superficial injection just prior to arthrotomy (early stage periarticular injection group) or superficial injection after implanting the prosthesis (late-stage periarticular injection group) in patients undergoing unilateral TKA with 1:1 treatment allocation. In both groups, deep injection was performed according to the same schedule (just prior to implanting prosthesis). The solution consisted of 300 mg of ropivacaine, 8 mg of morphine, 40 mg of methylprednisolone, 50 mg of ketoprofen, and 0.3 mg of epinephrine mixed with normal saline to a final volume of 60 mL. All surgeries were managed under general anesthesia without any regional blocks. Registry-specified primary outcome was postoperative pain score at rest measured at the recovery room using a 100-mm visual analog scale (VAS). The VAS score was compared between two groups and assessed to reach the reported threshold values for the minimal clinically important difference (MCID) of 10 mm for the postoperative VAS score.

RESULTS

The VAS score at the recovery room was significantly lower in the early stage periarticular injection group than the late-stage periarticular injection group (23 ± 25 mm versus 39 ± 34 mm, respectively; 95% confidence interval 4-28 mm; p = 0.0078). The mean difference in the primary outcome fulfilled the MCID value.

CONCLUSIONS

Bringing forward the timing of periarticular injection may provide significant and clinically meaningful improvement in pain following TKA under general anesthesia.

LEVEL OF EVIDENCE

I.