Bradford S. Waddell

Establishing a Role for Vancomycin Powder Application for Prosthetic Joint Infection Prevention—Results of a Wear Simulation Study

Topical vancomycin powder (VP) has shown efficacy and safety in decreasing post-operative spine infections. VP use in arthroplasty has not been established. Concerns remain for third-body wear with the addition of crystalline substrate at the implant interface. The studys purpose was to compare wear behavior of CoCr on UHMWPE to identical wear couples with VP. A six-station wear simulator was utilized and cyclic articulations were run for 10 million cycles (Mc). UHMWPE wear was measured using photography, stereomicroscopy, and gravimetric measurement. There were no differences in wear mark length (P = 0.43), width (P = 0.49), or gravimetric wear at 10 Mc (P = 0.98). VP and control groups lost 0.32 and 0.33 mg, respectively. VP may have a role in PJI prevention. A well-designed clinical study is needed.

Favorable Early Results of Impaction Bone Grafting With Reinforcement Mesh for the Treatment of Paprosky 3B Acetabular Defects.

BACKGROUND We present the early institutional experience with the use of impaction bone grafting, mesh augmentation, and cement fixation of an all-polyethylene cup for the treatment of Paprosky 3B acetabular defects during revision total hip arthroplasty. METHODS Between 2005 and 2014, 21 patients (9 men, 12 women) with Paprosky 3B acetabular defects who underwent revision total hip arthroplasty using this technique were reviewed clinically and radiographically. Average age and body mass index were 72.4 (range, 48-91) years and 24.5 (range, 18.9-31) kg/m2, respectively. All patients underwent revision for aseptic loosening. Surgical technique included the use of a peripheral mesh to contain the defect, followed by impaction of morselized fresh-frozen bone graft and cement fixation of a polyethylene cup. RESULTS Complications occurred in 6 patients (29%) including limp (2), sciatic nerve palsy that resolved (1), limb length discrepancy (1), and greater trochanteric fracture (1). After an average follow-up of 47 months (range, 13-128 months), the average Hospital for Special Surgery hip score was 35.5 (range, 20-40). Radiographic assessment revealed cephalad cup migration of 2.29 mm (range, 0-20 mm) and medial migration of 1.57 mm (range, 0-6 mm). One patient has radiographic loosening and no symptoms 120 months postoperatively. No patient returned to the operating room for a related reason or is scheduled to undergo acetabular re-revision surgery. CONCLUSION Impaction bone grafting is a reliable technique for the treatment of Paprosky 3B acetabular defects. It restores bone stock like no other available for addressing these defects. Longer follow-up is required to assess potential deterioration of fixation.

Early intraprosthetic dislocation in dual-mobility implants: a systematic review

Background Dual mobility implants are subject to a specific implant-related complication, intraprosthetic dislocation (IPD), in which the polyethylene liner dissociates from the femoral head. For older generation designs, IPD was attributable to late polyethylene wear and subsequent failure of the head capture mechanism. However, early IPDs have been reportedly affecting contemporary designs. Methods A systematic review of the literature according to the preferred reporting items for systematic reviews and meta-analyses guidelines was performed. A comprehensive search of PubMed, MEDLINE, Embase, and Google Scholar was conducted for English articles between January 1974 and August 2016 using various combinations of the keywords “intraprosthetic dislocation,” “dual mobility,” “dual-mobility,” “tripolar,” “double mobility,” “double-mobility,” “hip,” “cup,” “socket,” and “dislocation.” Results In all, 16 articles met our inclusion criteria. Fourteen were case reports and 2 were retrospective case series. These included a total of 19 total hip arthroplasties, which were divided into 2 groups: studies dealing with early IPD after attempted closed reduction and those dealing with early IPD with no history of previous attempted closed reduction. Early IPD was reported in 15 patients after a mean follow-up of 3.2 months (2.9 SD) in the first group and in 4 patients after a mean follow-up of 15.1 months (9.9 SD) in the second group. Conclusions Based on the current data, most cases have been preceded by an attempted closed reduction in the setting of outer, large articulation dislocation, perhaps indicating an iatrogenic etiology for early IPD. Recognition of this possible failure mode is essential to its prevention and treatment.

Comparison of Ocular Radiation Exposure Utilizing Three Types of Leaded Glasses.

Study Design. Anthropomorphic phantoms were used to measure radiation exposure to the surgeon phantoms eye. Groups analyzed were: Group 1—no glasses (None); Group 2—leaded lenses without lead sides (WOLS); Group 3—leaded lenses with lead sides (WLS); and Group 4—sport wraparound leaded glasses (Sport). Glasses were 0.75 mm lead equivalent. Objective. To evaluate the efficacy of three types of leaded eyeglasses at reducing radiation exposure to the lens during typical views of minimally invasive spine surgery. Summary of Background Data. Minimally invasive spine surgery relies upon fluoroscopic x-ray. Ocular radiation exposure is associated with cataract formation. Leaded glasses can reduce ocular radiation exposure. Methods. Fifteen individual 20-second exposures with the fluoroscopic C-arm in the anteroposterior (AP) and lateral positions, with phantom head positioned at 0, 45, and 90 degrees to the fluoroscope were performed. Radiation was measured using a solid-state dosimeter. Student t test was used to calculate significance. Results. All glasses (WOLS, WLS, and Sport) had significant reductions in ocular radiation versus no glasses, at all individual head positions (P ⩽ 1.31 × 10−34). Sport had significantly lower ocular radiation dose than WLS at all head positions except at 90 degrees AP (P = 0.001). WOLS had significantly lower ocular radiation dose than Sport in three out of six cases including phantom head at 0 degrees AP (P = 0.0003), 90 degrees AP (P = 4.46 × 10−10), and 90 degrees lateral (P = 7.38 × 10−28). WOLS had significantly lower radiation dosage at all head positions than WLS except at 45 degrees AP (P = 0.303). All glasses resulted in a significant reduction in total radiation dose from all head positions over no glasses (P ⩽ 8.37 × 10−32). Conclusion. We demonstrate a significant reduction in ocular radiation exposure with all three types of leaded glasses. Lead glasses, WOLS and Sport, were the most effective at reducing ocular radiation. Level of Evidence: 3

Reconstruction of non-contained acetabular defects with impaction grafting, a reinforcement mesh and a cemented polyethylene acetabular component

This review summarises the technique of impaction grafting with mesh augmentation for the treatment of uncontained acetabular defects in revision hip arthroplasty. The ideal acetabular revision should restore bone stock, use a small socket in the nearanatomic position, and provide durable fixation. Impaction bone grafting, which has been in use for over 40 years, offers the ability to achieve these goals in uncontained defects. The precepts of modern, revision impaction grafting are that the segmental or cavitary defects must be supported with a mesh; the contained cavity is filled with vigorously impacted morselised fresh‐frozen allograft; and finally, acrylic cement is used to stabilise the graft and provide rigid, long‐lasting fixation of the revised acetabular component. Favourable results have been published with this technique. While having its limitations, it is a viable option to address large acetabular defects in revision arthroplasty.

Financial Analysis of Treating Periprosthetic Joint Infections at a Tertiary Referral Center

BACKGROUND Periprosthetic joint infection (PJI) is a significant challenge to the orthopedic surgeon, patient, hospital, and insurance provider. Our study compares the financial information of self-originating and referral 2-stage revision hip and knee surgeries at our tertiary referral center for hip or knee PJI over the last 4 years. METHODS We performed an in-house retrospective financial review of all patients who underwent 2-stage revision hip or knee arthroplasty for infection between January 2008 and August 2013, comparing self-originating and referral cases. RESULTS We found an increasing number of referrals over the study period. There was an increased cost of treating hips over knees. All scenarios generated a positive net income; however, referral hip PJIs offered lower reimbursement and net income per case (although not statistically significant), whereas knee PJIs offered higher reimbursement and net income per case (although not statistically significant). CONCLUSION With referral centers treating increased numbers of infected joints performed elsewhere, we show continued financial incentive in accepting referrals, although with less financial gain than when treating ones own hip PJI and an increased financial gain when treating referral knee PJIs.

Comparison of Efficacy and Tolerability of Hylan G-F 20 in Patients with and without Effusions at the Time of Initial Injection

An effusion at the onset of viscosupplementation has been thought to diminish the efficacy and increase adverse event rates. This study compares efficacy of hylan G-F 20 in patients with and without an effusion. Patients with knee osteoarthritis (OA) received three weekly injections of hylan G-F 20. A total of 50 patients with an effusion requiring aspiration were compared with 50 matched patients without an effusion. Outcome measurements included Western Ontario and McMasters Universities Osteoarthritis index (WOMAC) and visual analog scale (VAS). Patients were followed for 26 weeks. Both effusion and control group VAS was significantly lowered at all time points. WOMAC scores improved (p < 0.025) at all visits in the effusion group except for WOMAC A-1 week 14. Control WOMAC scores also significantly improved at all visits (p < 0.027), except for full WOMAC and WOMAC A-1 at week 1. Neither group experienced an adverse event. Presence of an effusion at onset of viscosupplementation requiring aspiration does not negatively impact efficacy of hylan G-F 20 or increase adverse event rates.

Have large femoral heads reduced prosthetic impingement in total hip arthroplasty

Background: Prosthetic impingement is implicated in dislocation after total hip arthroplasty (THA). While use of larger diameter femoral heads reduces the incidence of dislocation, the effect of larger heads upon impingement rate is unknown. We assessed retrieved THA components for evidence of impingement to determine if large femoral heads reduced the rate of impingement in primary THA and what factors might influence impingement. Methods: Liners from 97 primary THAs retrieved at revision arthroplasty were scored for evidence of impingement, defined as wear or deformation on the rim of the component. Component inclination and version were measured from anteroposterior and cross-table lateral radiographs. Results: Independent of revision diagnosis, 77% of liners demonstrated evidence of impingement. Impingement was less prevalent and less severe as head size increased. Severe impingement was observed in 50% of the liners with 28-mm heads, 15% of liners with 32-mm heads, and 21% of liners with 36-mm heads. Regardless of head size, 76% of liners revised for instability demonstrated impingement. Decreased head-neck ratio, use of an elevated liner, increased length of implantation, and increased version were associated with increased severity of impingement. Discussion: We showed that larger head sizes are associated with decreased incidence of impingement on retrieved acetabular liners when compared to smaller head sizes. Larger heads have reduced but not eliminated impingement, which remains a potential source of instability.

Technology in Arthroplasty: Are We Improving Value?

Purpose of ReviewTotal joint arthroplasty is regarded as a highly successful procedure. Patient outcomes and implant longevity, however, are related to proper alignment and position of the prostehses. In an attempt to reduce outliers and improve accuracy and precision of component position, navigation and robotics have been introduced. These technologies, however, come at a price. The goals of this review are to evaluate these technologies in total joint arthroplasty and determine if they add value.Recent FindingsRecent studies have demonstrated that navigation and robotics in total joint arthroplasty can decrease outliers while improving accuracy in component positioning. While some studies have demonstrated improved patient reported outcomes, not all studies have shown this to be true. Most studies cite increased cost of equipment and longer operating room times as the major downsides of the technologies at present. Long-term studies are just becoming available and are promising, as some studies have shown decreased revision rates when navigation is used. Finally, there are relatively few studies evaluating the direct cost and value of these technologies.SummaryNavigation and robotics have been shown to improve component position in total joint arthroplasty, which can improve patient outcomes and implant longevity. These technologies offer a promising future for total joint arthroplasty.

A detailed review of hip reduction maneuvers: a focus on physician safety and introduction of the Waddell technique

Dislocation of the hip is a well-described event that occurs in conjunction with high-energy trauma or postoperatively after total hip arthroplasty. Bigelow first described closed treatment of a dislocated hip in 1870, and in the last decade many reduction techniques have been proposed. In this article, we review all described techniques for the reduction of hip dislocation while focusing on physician safety. Furthermore, we introduce a modified technique for the reduction of posterior hip dislocation that allows the physician to adhere to the back safety principles set for by the Occupational Safety and Health Administration.