Intra-Articular Corticosteroid Injection After Total Knee Replacement: Is it Safe?

Recalcitrant pain after total knee replacement (TKR) is sometimes treated with intra-articular steroid injections (IASI), with few studies reporting on the risk of subsequent periprosthetic joint infection (PJI). This is a systematic review to evaluate the incidence and risk of PJI after IASI into a total knee replacement. We searched online databases using the keywords "total knee replacement," "total knee arthroplasty," "steroids" and "intra-articular injection." A total of 7386 articles (PubMed - 91, Embase - 70, Web of Science - 57, CINAHL - 8, and Google Scholar - 7160) were retrieved on the initial search. After applying exclusion criteria, four articles were included in this review for evaluation and statistical analysis. There were no level one or two studies. The incidence of infection after IASI at 12 months was 138/6499 or 2.1%, while the incidence of infection rate among controls at 12 months was 158/11256 or 1.4%. A chi-square test showed that the difference in infection rate was significant (p = 0.0002424). A caveat is that simple statistical test results are virtually guaranteed to be statistically significant with large sample size. IASI into a TKR is not a benign procedure and that may be associated with a significantly increased risk of subsequent periprosthetic joint infection. We, therefore, recommend against IASI into a TKR until better studies can be performed to determine their safety and efficacy.

Modes of failure of knotted and knotless suture anchors in an arthroscopic bankart repair model with the capsulolabral tissues intact.

The purpose of this study was to assess failure modes of knotless and knotted anchors in a Bankart repair model with the capsulolabral soft tissues intact. Previous reports used a model stripped of soft tissues. In 8 matched pairs of cadaver shoulders, a Bankart lesion was repaired arthroscopically using either 2 Bio-SutureTak anchors (Arthrex, Naples, Florida) or 2 Bioknotless anchors (Mitek, Westwood, Massachusetts). The shoulders were mounted with the repaired capsulolabral tissues attached to a custom sinusoidal clamp, and were tested in cyclic loading (20-80 N, 100 cycles, 0.5 mm/s) and then load to failure (1.25 mm/s). Cut-through at the suture-tissue interface (23/32 anchors) was more common than pullout at the anchor-bone interface (9/32) as a mode of failure (P = .02). Failure at the suture-tissue interface occurred in 10/16 knotted and 13/16 knotless anchors. Mean (SD) ultimate load of knotted vs knotless anchors was 125.3 (67.4) N and 96.9 (95.1) N, respectively. Mean (SD) stiffness of knotted vs knotless anchors was 20.9 (6.4) N/mm and 19.8 (8.6)N/mm, respectively. We concluded that both knotted and knotless anchors fail most often at the suture-tissue interface. The tested model with the capsulolabral tissues intact is distinct from previous models, which tested the anchor-bone interface only.

Fix and flap in the era of vacuum suction devices: What do we know in terms of evidence based medicine?

INTRODUCTION: The concept of immediate or early fixation and soft tissue coverage of open fractures is frequently referred to as 'fix and flap,' and negative pressure wound therapy (NPWT) has had a major impact in this area. This article aims to review concepts and evidence relevant to the use of NPWT in open fractures. REVIEW OF OPEN FRACTURE MANAGEMENT: Muscle flaps in open fractures do well in part because they improve blood supply to the underlying fracture. Outcomes of muscle flaps are best when done acutely, before bacterial colonisation. The colonised subacute wound is managed with 'open-wound techniques' until it becomes a chronic localised wound, when flap coverage is again indicated. NPWT provides a useful adjunct in this process as the zone of injury is determined. VACUUM-ASSISTED CLOSURE: REVIEW OF BASIC AND CLINICAL SCIENCE LITERATURE: Proposed mechanisms of action of NPWT include: increased blood flow, decreased oedema, cytokine release induced by mechanical stretch and increased lactate and oxygen tension in the tissue with induction of collagen transcription and angiogenesis. VACUUM-ASSISTED CLOSURE IN OPEN FRACTURES: NPWT to open fractures caused early appearance of healthy granulation tissue, a reduction in wound area and allowed simpler soft tissue procedures for wound closure. NPWT also improved clinical survival of muscle flaps despite occluded flap venous outflow. SUMMARY: The aim in open fractures is to stabilize the fracture and achieve soft tissue coverage before infection develops. NPWT, applied as a temporizing dressing, simplifies soft tissue coverage on the 'reconstructive ladder.' The only Level-I data on that topic showed a significant decrease in infections. However, NPWT does not allow delay in soft tissue coverage. NPWT increases the 'take rate' of skin grafts, skin substitutes and composite skin grafts and allows quicker graft incorporation.

Interference screw versus suture anchor fixation for subpectoral tenodesis of the proximal biceps tendon: a cadaveric study.

PURPOSE: The purpose of this study was to compare the biomechanical properties of 2 fixation methods for subpectoral proximal biceps tenodesis. METHODS: In 9 matched pairs of cadaveric shoulders, an open subpectoral tenodesis was performed 1 cm proximal to the inferior border of the pectoralis major tendon by use of either an 8 x 12-mm Bio-Tenodesis screw (Arthrex, Naples, FL) with No. 2 FiberWire sutures (Arthrex) or a 5.5-mm Bio-Corkscrew double-loaded suture anchor (Arthrex) with No. 2 FiberWire sutures. The specimens were dissected and mounted in a material testing machine. Cyclic loading (20 to 60 N, 100 cycles, 0.5 mm/s, 5-N preload) was performed, followed by an unloaded 30-minute rest, a 5-N preload, and a load-to-failure protocol (1.25 mm/s) with a 100-lb load cell. Ultimate load (in Newtons), stiffness (in Newtons per millimeter), and modes of failure were recorded. Data were analyzed by use of paired t tests and Wilcoxon signed rank tests. RESULTS: Proximal biceps tenodeses with Bio-Tenodesis screws had a significantly higher mean load to failure (169.6 +/- 50.5 N; range, 99.6 to 244.7 N) than those with Bio-Corkscrew suture anchors (68.5 +/- 33.0 N; range, 24.2 to 119.4 N) (P = .002). Bio-Tenodesis screws also had a significantly higher stiffness (34.1 +/- 9.0 N/mm; range, 20.6 to 48.9 N/mm) than Bio-Corkscrews (19.3 +/- 10.5; range, 5.9 to 32.9 N/mm) (P = .038). CONCLUSIONS: In this cadaveric study the Bio-Tenodesis screw showed a statistically significantly higher load to failure and significantly higher stiffness than the Bio-Corkscrew anchor when used for tenodesis of the proximal biceps tendon in a subpectoral location. CLINICAL RELEVANCE: Biomechanical comparison of these 2 fixation techniques provides information on stiffness and load to failure of alternate fixation methods.