Place In Space Research Articles

Reconstruction Plate-Based Antibiotic Cement Spacers: Clinical Outcomes and Description of Technique.

The standard of care for chronic deep peri-prosthetic hip infection is a two-stage exchange with placement of a temporary antibiotic cement spacer and treatment with intravenous antibiotics. Several commercially available cement spacer options exist. We report on a novel antibiotic spacer that may be an efficient, cost-effective alternative. Medical records of all patients treated for deep peri-prosthetic hip infection after total hip arthroplasty between 2004 and 2012 were reviewed. Each antibiotic spacer was constructed from a 12- to 16-hole recon plate bent to provide adequate soft tissue tension and a cement ball that matched the acetabulum. Premature failure of the plate and duration of implantation were measured. Failure was defined as fracture of the plate or dissociation of the cement head from the plate. Costs were compared with commercially available cement spacers. A total of 24 spacers were identified in 21 patients (mean age 68.9 years, mean body-mass index 26.4). The mean time between spacer placement and re-implantation was 6.4 months (range: 1.8-18 months). One patient had an indolent infection that was unresponsive to antibiotic therapy and required a hip disarticulation. At the time of reimplantation, 17 of 17 handmade spacers had no failures. Of the premade spacers, six of the seven had no failures. One premade spacer fractured at the femoral component trunion. The cost of the plate and antibiotic cement was $909-1000, approximately $5000 less than premade spacers. Antibiotic spacers can be readily constructed intraoperatively and offer good clinical outcomes with a low incidence of failure. This type of spacer saved $5000 per patient.

Outcomes of Shoulder Arthroplasty Performed for Postinfectious Arthritis.

BackgroundThe purpose of this study was to evaluate the functional outcomes, infection rate, and complications associated with shoulder arthroplasty for sequelae of prior septic arthritis.MethodsThis is a retrospective cohort study of 17 patients who underwent shoulder arthroplasty for sequelae of septic arthritis. Patients were analyzed for patient-reported outcomes, complications, and reoperations.ResultsThe 17 patients in this cohort were an average age of 65.4 ± 12.2 years old, were 58.8% male, and had an average body mass index of 27.9 ± 4.1 kg/m2. These patients underwent 14 reverse shoulder arthroplasties (RSAs; 11 after antibiotic spacer placement), one anatomic total shoulder arthroplasty after antibiotic spacer placement, and two hemiarthroplasties (both after antibiotic spacer placement). Two patients underwent reoperation (dislocated RSAs). There were four complications (23.5%): two RSA dislocations, one acromial stress fracture, and one atraumatic rotator cuff tear after hemiarthroplasty. There were no cases of postoperative wound complications or infection. At an average of 4.1 ± 1.8 years of follow-up for all 17 of 17 cases, the average visual analogue scale pain score was 4.6 ± 2.3, average Single Assessment Numeric Evaluation Score was 59.3 ± 23.7, average American Shoulder and Elbow Surgeons Score was 57.6 ± 15.5, and average Simple Shoulder Test was 6.9 ± 2.6 based on “yes” responses.ConclusionsShoulder arthroplasty after septic arthritis had inconsistent functional outcomes and high complication rates but no reinfection.

Placement of an absorbable rectal hydrogel spacer in patients undergoing low-dose-rate brachytherapy with palladium-103

PurposeRates of rectal toxicity after low-dose-rate (LDR) brachytherapy for prostate cancer are dependent on rectal dose, which is associated with rectal distance from prostate and implanted seeds. Placement of a hydrogel spacer between the prostate and rectum has proven to reduce the volume of the rectum exposed to higher radiation dose levels in the setting of external beam radiotherapy. We present our findings with placing a rectal hydrogel spacer in patients following LDR brachytherapy, and we further assess the impact of this placement on dosimetry and acute rectal toxicity. Methods and MaterialsBetween January 2016 and April 2017, 74 patients had placement of a hydrogel spacer, immediately following a Pd-103 seed-implant procedure. Brachytherapy was delivered as follows: as a monotherapy to 26 (35%) patients; as part of planned combination therapy with external beam radiotherapy to 40 (54%) patients; or as a salvage monotherapy to eight (11%) patients. Postoperative MRI was used to assess separation achieved with rectal spacer. Acute toxicity was assessed retrospectively using Radiation Oncology Therapy Group radiation toxicity grading system. Rectal dosimetry was compared with a consecutive cohort of 136 patients treated with seed implantation at our institution without a spacer, using a 2-tailed paired Student's t test (p < 0.05 for statistical significance). ResultsOn average, 11.2-mm (SD 3.3) separation was achieved between the prostate and the rectum. The resultant mean rectal volume receiving 100% of prescribed dose (V100%), dose to 1 cc of rectum (D1cc), and dose to 2 cc of rectum (D2cc) were 0 (SD 0.05 cc), 25.3% (SD 12.7), and 20.5% (SD 9.9), respectively. All rectal dosimetric parameters improved significantly for the cohort with spacer placement as compared with the nonspacer cohort. Mean prostate volume, prostate V100 and dose to 90% of gland (D90) were 29.3 cc (SD 12.4), 94.0% (SD 3.81), and 112.4% (SD 12.0), respectively. Urethral D20, D5cc, and D1cc were 122.0% (SD 17.27), 133.8% (SD 22.8), and 144.0% (SD 25.4), respectively. After completing all treatments, at the time of first the followup, 7 patients reported acute rectal toxicity—6 experiencing Grade 1 rectal discomfort and 1 (with preexisting hemorrhoids) experiencing Grade 1 bleeding. ConclusionsInjection of rectal spacer is feasible in the post-LDR brachytherapy setting and reduces dose to the rectum with minimal toxicity. Prostate and urethral dosimetries do not appear to be affected by the placement of a spacer. Further studies with long-term followup are warranted to assess the impact on reduction of late rectal toxicity.

Implant Removal and Spacer Placement for Infected Shoulder Arthroplasty: Risk Factors for Repeat Procedures, Spacer Retention, and Mortality.

Current studies reporting on patients following prosthesis removal and spacer placement for periprosthetic joint infection (PJI) of the shoulder have largely been descriptive and insufficiently powered to determine risk factors for outcomes other than reimplantation. The objective of the present study is to provide a national perspective on the 1-year outcomes following prosthesis removal and spacer placement and risk factors for outcomes other than reimplantation for treatment of PJI following shoulder arthroplasty. A national database was queried for Medicare patients who underwent prosthesis removal and spacer placement for PJI between 2005 and 2012. These patients were then evaluated for 5 major study endpoints including: (1) replantation of a shoulder prosthesis within 1year postoperatively, (2) a repeat irrigation and debridement with second antibiotic spacer placement procedure within 1year postoperatively, (3) in-hospital death within 1year postoperatively, (4) a shoulder Girdlestone-type procedure within 1year postoperatively, and (5) the remaining patients, who were considered to have a retained spacer. Patients with a study endpoint within 1year postoperatively were included in the study: (1) mortality, (2) repeat debridement, (3) resection arthroplasty, and (4) reimplantation. While it is possible that some patients were not captured due to errors in coding, it is unlikely that patients were lost to follow-up due to change in location of services, given that the database captures all episodes of care that are coded throughout the USA. Independent risk factors were evaluated using logistic regression analysis. Nine hundred seventy-five patients who underwent prosthesis removal and spacer placement were included. Within 1year postoperatively, 21 patients died (2.2%), 70 patients had a repeat debridement procedure (7.2%), 55 patients had a resection arthroplasty procedure (5.6%), 349 patients retained their spacers (35.8%), and the remaining 480 patients had a shoulder arthroplasty reimplanted (49.2%). Numerous independent risk factors exist for all outcomes studied. The fate of antibiotic spacers placed for PJI of the shoulder at 1year is variable, with numerous independent risk factors for outcomes other than reimplantation. Patients with PJI following total shoulder arthroplasty should be counseled on the risk factors that influence the outcomes of staged revision for shoulder PJI.

El paseo imaginado. Dibujo y realidad en la construcción de un barrio funcionalista: Huerta del Rey (Valladolid)

&lt;p&gt;Huerta del Rey es un polígono residencial de Valladolid de manzana abierta con cierto prestigio nacional (1950s-1990s) que hoy se aproxima al paradigma de ciudad en el verde que ansiaba el Movimiento Moderno.&lt;/p&gt;&lt;p&gt;Aunque está bastante documentado su proceso de desarrollo, las investigaciones no se han detenido en cómo se ha representado la creación de dicho paisaje “verde”. Buscamos en las fuentes originales de cada etapa para descubrir el dibujo o construcción de varios relatos en torno a ese objetivo abstracto común.&lt;/p&gt;&lt;p&gt;La colocación, representación e ideación del “verde” generalmente remite a una disciplina poco valorada en nuestro país. Pero aquí nos descubre el reconocimiento de su importancia por parte de algunos profesionales “enterados” y preocupados, que posibilitó su configuración y riqueza de matices, a pesar de que no haya sido el resultado de un diálogo prioritario y cohesionado. Entre pérdidas, olvidos y operaciones tardías destaca la potencia de un paseo.&lt;/p&gt;

Periprosthetic knee infection: two stage revision surgery.

Periprosthetic joint infection (PJI) remains a serious complication following a total joint replacement. Diagnosis and management of PJI is challenging for surgeons since there is no "gold standard". This challenging condition requires a coordinated management approach to achieve good patient outcomes. Further difficulties involve choosing the optimal method to treat the periprosthetic joint infection. In this article, it is stressed the role of the two-stage revision: implant removal, debridement and placement of an antibiotic spacer, and antibiotic therapy with cessation prior to reimplantation. Published literature shows that two stage revision is a valid treatment option for periprosthetic joint infection.

Paper #8 - Stage 1 shoulder arthroplasty: risk factors for repeat stage 1, spacer retention and mortality

Objectives: Reports of two-stage procedures for infection after shoulder arthroplasty, which includes prosthesis removal, antibiotic cement spacer placement, and plan for later re-implantation after eradication of infection, are limited to very small institutional series. The objective of the present study is to provide a national perspective on the outcomes at one year following stage 1 shoulder arthroplasty (removal of prosthesis and implantation of antibiotic cement spacer) and risk factors for outcomes other than re-implantation during that time period.

Risk Factors for Repeat Debridement, Spacer Retention, Amputation, Arthrodesis, and Mortality After Removal of an Infected Total Knee Arthroplasty With Spacer Placement

BackgroundChronic periprosthetic joint infection (PJI) after total knee arthroplasty (TKA) is most commonly addressed with a 2-stage exchange procedure. The purpose of this study is to examine the natural history of patients who have undergone prosthesis removal and spacer placement and evaluate risk factors for outcomes other than reimplantation. MethodsPatients who underwent removal of an infected TKA and placement of an antibiotic spacer for PJI were identified in a Medicare database. Patients with a study outcome within 1 year were then identified: (1) in hospital mortality, (2) knee arthrodesis, (3) amputation, (4) repeat debridement procedure without reimplantation, and (5) reimplantation. Independent risk factors for these outcomes were evaluated with a multivariate logistic regression analysis. ResultsA total of 18,533 patients were included. Within 1 year postoperatively, 691 patients (3.7%) died in a hospital setting, 852 patients (4.5%) underwent a knee arthrodesis, 574 patients (3.1%) underwent an amputation, 2683 patients (14.5%) underwent a repeat debridement procedure without being reimplanted, 2323 patients (12.5%) retained their spacer, and 11,420 patients (61.6%) underwent spacer removal and reimplantation within 1 year. Numerous independent patient-related risk factors for these outcomes were identified. ConclusionA large number of patients (38.4%) do not undergo reimplantation within 1 year of prosthesis removal and spacer placement. Outcomes after prosthesis removal and antibiotic spacer placement are variable, and there are several independent risk factors for such outcomes that may be used to develop and improve existing treatment strategies for patients presenting with chronic PJI after TKA.

Importance and Effectiveness of Representing the Shapes of Cosserat Rods and Framed Curves as Paths in the Special Euclidean Algebra

We discuss how the shape of a special Cosserat rod can be represented as a path in the special Euclidean algebra. By shape we mean all those geometric features that are invariant under isometries of the three-dimensional ambient space. The representation of the shape as a path in the special Euclidean algebra is intrinsic to the description of the mechanical properties of a rod, since it is given directly in terms of the strain fields that stimulate the elastic response of special Cosserat rods. Moreover, such a representation leads naturally to discretization schemes that avoid the need for the expensive reconstruction of the strains from the discretized placement and for interpolation procedures which introduce some arbitrariness in popular numerical schemes. Given the shape of a rod and the positioning of one of its cross sections, the full placement in the ambient space can be uniquely reconstructed and described by means of a base curve endowed with a material frame. By viewing a geometric curve as a rod with degenerate point-like cross sections, we highlight the essential difference between rods and framed curves, and clarify why the family of relatively parallel adapted frames is not suitable for describing the mechanics of rods but is the appropriate tool for dealing with the geometry of curves.

Development and trial of athletic T-shirt using spacer blocks to enhance ventilation

PurposeIn previous studies, enlarging the air gap between fabric and the skin through the placement of spacer blocks has been proven to improve air ventilation, particularly when the pumping effect is activated during movement. These studies evaluated only the total thermal insulation (Rt) and moisture vapour resistance (Ret) by using a fabric thermal manikin. The purpose of this paper is to report the experience, perceived comfort level, and ventilation effect of two designed T-shirts in a wearer trial.Design/methodology/approachAn athletic T-shirt (Vented Design) was designed by attaching spacer blocks to the underside of the fabric to enlarge the air gap. Eight subjects participated in the wearer trial, which comprised 30 min treadmill running, followed by 10 min of rest. At different points during the 40 min test period, subjects rated their body coolness, skin dryness, and overall comfort of the designed T-shirt. The testing was repeated with participants wearing the same T-shirt but without spacer blocks, which served as a control garment. The mean skin temperature of each subject was also measured to support survey findings.FindingsThe data were evaluated using independent t-tests. The T-shirt with spacer blocks provided higher ventilation than the control T-shirt after 10 min of running. Research limitations – because of limited resources, only eight subjects were recruited to this study. In addition, more T-shirt designs should be tested in the future to elucidate how T-shirt design affects ventilation performance.Originality/valueThis study investigated a T-shirt design wherein the air gap between the skin surface and fabric was increased. The results of the wearer trial showed that this design could be adopted as a design brief for further design development of related clothing. This study has implications for clothing designers developing functional clothing with improved ventilation.

Clinical evaluation of microendoscopy-assisted extreme lateral interbody fusion

Extreme lateral interbody fusion (XLIF) has rapidly become a popular operative procedure for lumbar canal stenosis and scoliosis. This approach provides direct access to the lateral aspect of the disc with minimal disruption of spinal structures, including ligaments and muscles. However, it involves risk of injuries to the lumbar nerve plexus, segmental artery and intestinal tract because of the limited surgical field. This study aimed to clarify the benefit of using a microendoscope to prevent these injuries. A total of 96 consecutive patients treated by a single surgeon were retrospectively analyzed. The basic approach via the psoas muscle was performed in accordance with the conventional XLIF procedure. Operative manipulations, such as insertion of the shim, discectomy, endplate preparation and intervertebral spacer placement, were performed with the assistance of a microendoscope. Preoperative and postoperative neurological status were evaluated using the Japanese Orthopedic Association (JOA) scores and the Oswestry Disability Index (ODI). Eighty-four patients underwent surgery for a single vertebral level, nine patients underwent surgery for 2 levels and three patients underwent surgery for 3 levels (average, 1.2 levels). The average age of patients was 61 years (range, 22-83 years); the mean follow-up period was 18 months (range, 3-36 months). Average preoperative and postoperative JOA scores were 11.9 and 15.6, with a mean recovery rate of 33%. Average preoperative and postoperative ODI scores were 38.6 and 19.1. There were 3 (3.1%) complications: 2 end-plate fractures and 1 deep surgical site infection. There were no bowel perforations or vascular injuries. Microendoscopy assistance is one solution for severe visceral and vascular injuries related to XLIF.

Intramedullary placement of ventricular shunts: a review of using bone as a distal cerebrospinal absorption site in treating hydrocephalus.

Intraosseous (IO) vascular access has been used since the Second World War and is warranted when there is an emergency and/or urgent need to replenish the vascular pool. Despite long-term and satisfactory results from delivering large quantities of intravenous fluid via the medullary space of bone, use of this space for a distant receptacle for cerebrospinal fluid (CSF) diversion has seldom been considered. The current paper reviews the literature regarding the bony medullary space as a receptacle for intravenous fluid and CSF. Previous authors have demonstrated the potential of the diploic space of the calvaria for CSF shunting. Pugh and colleagues tested the ability of the cranium to receive and absorb a small amount of tracer fluid. The literature suggests that intraosseous placement of ventricular diversionary shunts is an alternative to more traditional sites such as the pleural cavity and peritoneum. When these latter locations are not available or are contraindicated, placement in the medullary space of bone is another option available to the surgeon.

Role of MRI in the Use of an Absorbable Hydrogel Spacer in Men Undergoing Radiation Therapy for Prostate Cancer: What the Radiologist Needs to Know.

Hydrogel spacers have a novel role in the treatment of low- and intermediate-risk prostate cancer with dose-escalated radiation therapy. Given the growing number of patients undergoing treatment with radiation therapy, the use of hydrogel spacers is expected to increase. The purpose of this article is to review what a radiologist needs to know about the imaging of hydrogel spacers, including MRI technique and appearance on CT and MRI. MRI has a critical role in the evaluation of hydrogel spacer placement and is used to facilitate contouring by the radiation oncologist. The radiologist should be familiar with the imaging appearance of hydrogel spacers on CT and MRI to avoid interpretation pitfalls and errors.

Abstract LB-264: Preclinical evaluation of DNA-PK as a therapeutic target in prostate cancer

Abstract Prostatic adenocarcinoma (PCa) is dependent on androgen receptor (AR) signaling at all stages of disease, as AR activation induces both cell proliferation and survival. Though organ–confined disease can be treated, the response is transient. Reactivation of AR leads to castration resistant prostate cancer (CRPC), which remains fatal. Previously published studies demonstrate that AR activation promotes tumor cell survival and proliferation through a feed-forward loop involving the DNA repair factor DNA-dependent protein kinase (DNA-PK). Recent data from our lab has highlighted the role of DNA-PK in DNA damage repair as well as transcriptional regulation of pro-metastatic signaling. Strikingly, DNA-PK is the most deregulated kinase in metastatic CRPC. DNAPK is highly elevated and hyperactivated, and is an independent predictor of metastasis and overall survival in patients with high-risk disease. Concordantly, DNAPK suppression attenuated DNA-PK functions in NHEJ and transcriptional regulation. DNA-PK inhibition is sufficient to prevent proliferation in vitro and ex vivo, as well as tumor metastasis in vivo. Combined these findings highlight importance of DNA-PK functions as a transcriptional regulator and a mediator of NHEJ DNA repair and nominate it as a therapeutic target in PCa. Data presented here will interrogate the translational capacity of a specific DNA-PK inhibitor, a dual DNA-PK/TOR kinase inhibitor and a specific TOR kinase inhibitor in CRPC models. Currently, CC-115, a dual kinase inhibitor, is the only DNA-PK inhibitor in Phase1/2 trial in combination with Enzalutamide in PCa. Unbiased transcriptomic analyses were performed and will be used to identify mechanisms of action that lead to suppression of PCa growth in vitro and ex vivo. These findings will provide insight in the effectiveness of DNA-PK inhibitors as a single agent or combinatorial treatments and provide rational for its placement in the correct clinical space. Citation Format: Emanuela Dylgjeri, Jonathan F. Goodwin, Christopher M. McNair, Ayesha A. Shafi, Vishal Kothari, Felix Feng, Dana Rathkop, Karen Knudsen. Preclinical evaluation of DNA-PK as a therapeutic target in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-264. doi:10.1158/1538-7445.AM2017-LB-264

A retrospective analysis of risk factors for IPP reservoir entry into the peritoneum after abdominal wall placement.

Placement of an inflatable penile prosthesis (IPP) is the most effective treatment modality for men with ED refractory to medical management. We have previously demonstrated a protocol for IPP reservoir placement within the abdominal wall musculature, which was shown to be a safer location than traditional placement in the retropubic space of Retzius. The aim of this study was to review our complications with IPP reservoir entry into the peritoneum after abdominal wall placement of the reservoir. We retrospectively reviewed our two patients with peritoneal entry of the reservoir after posterior to transversalis fascia and anterior to transversalis fascia placement during virgin and compromised IPP cases, respectively. Our goal was to assess common inherent patient and surgical factors that resulted in this complication in order to develop a management algorithm to prevent future occurrence during alternative reservoir placement. Peritoneal reservoir entry was identified in two patients. These patients were both noted to be thin (mean body mass index (BMI) 18.5 kg/m2), current or former smokers. Peritoneal entry was identified early after reservoir placement. Neither of the patients suffered bowel injury and both subsequently underwent successful reservoir removal and IPP replacement. Both are currently doing well with functional IPPs on follow-up. Peritoneal entry of the reservoir occurs very rarely and, in our series, occurred in a cohort of patients with low BMI and tobacco use history. We recommend early identification of similar patients and subsequent reservoir placement anterior to transversalis fascia with caution to prevent peritoneal entry.

Anarchitextures: Intermedial Encounters On The Screen

In this article I draw on architectural and choreographic ways of thinking to discuss how filmed material is transformed through projection and active and mobile spectatorship. Shifting my attention from what is projected to where it is projected, I expand the discourse beyond the single flat cinematic screen. I do this by concentrating on how the projected surface (its placement in space and its assembly with multiple screens) creates social encounters. This study accepts Rosenberg's definition of the screen as "a receptor of an otherwise ephemeral image and which reifies that image in the process of receiving it." Anarchitextures is a screen-based performance project through which I explored Eisensteinian montage to include a spatial and ambulatory practice. The project speaks to choreographic environments and events that use the screen as a socially engaged practice, and also poses some questions regarding the boundaries that appear to shape the screendance field.

Optimizing green space locations to reduce daytime and nighttime urban heat island effects in Phoenix, Arizona

The urban heat island effect is especially significant in semi-arid climates, generating a myriad of problems for large urban areas. Green space can mitigate warming, providing cooling benefits important to reducing energy consumption and improving human health. The arrangement of green space to reap the full potential of cooling benefits is a challenge, especially considering the diurnal variations of urban heat island effects. Surprisingly, methods that support the strategic placement of green space in the context of urban heat island are lacking. Integrating geographic information systems, remote sensing, spatial statistics and spatial optimization, we developed a framework to identify the best locations and configuration of new green space with respect to cooling benefits. The developed multi-objective model is applied to evaluate the diurnal cooling trade-offs in Phoenix, Arizona. As a result of optimal green space placement, significant cooling potentials can be achieved. A reduction of land surface temperature of approximately 1–2°C locally and 0.5°C regionally can be achieved by the addition of new green space. 96% of potential day and night cooling benefits can be achieved through simultaneous consideration. The results also demonstrate that clustered green space enhances local cooling because of the agglomeration effect; whereas, dispersed patterns lead to greater overall regional cooling. The optimization based framework can effectively inform planning decisions with regard to green space allocation to best ameliorate excessive heat.

Medial Gastrocnemius Flap in the Course of Treatment for an Infection at the Site of a Total Knee Arthroplasty.

The pedicled medial gastrocnemius flap provides a robust coverage option for most soft-tissue deficiencies over the distal anterior aspect of the knee encountered in the setting of an infection after total knee arthroplasty. Position the patient supine with an ipsilateral sterile thigh tourniquet to allow room for harvest of a split-thickness skin graft as needed. Perform the arthroplasty to address the underlying deep infection (e.g., irrigation and debridement with exchange of modular components, component removal with antibiotic spacer placement, antibiotic spacer exchange, or second-stage reimplantation) prior to the medial gastrocnemius flap that is utilized for soft-tissue coverage. Use one of two different surgical approaches for the exposure and elevation of the medial gastrocnemius muscle and the identification of its vascular pedicle: the medial approach or the posterior midline approach. Protect the sural artery pedicle in the popliteal fossa because it is key to raising a viable medial gastrocnemius flap. Rotate the flap and transpose it anteriorly over the defect either through a subcutaneous tunnel or by dividing the intervening skin bridge. Complete the layered skin closure and place a split-thickness skin graft over the remaining exposed muscle flap and a nonadherent compressive bolster dressing or negative-pressure device over the skin graft to prevent hematoma under the skin graft. Progress range of motion of the knee once the flap and graft show evidence of survival, while an appropriate antibiotic regimen is completed. We recently reported the largest English-language series, to our knowledge, of medial gastrocnemius flaps performed for soft-tissue coverage in the course of treatment for infection after total knee arthroplasty13.

Removal of an Infected Hip Arthroplasty Is a High-Risk Surgery: Putting Morbidity Into Context With Other Major Nonorthopedic Operations

BackgroundTwo-stage revision remains the most common approach to periprosthetic joint infection of total hip arthroplasty (THA) in the United States. The postoperative risks associated with removal of an infected prosthesis and placement of a spacer have not been thoroughly studied. MethodsPatients who underwent THA implant removal and spacer placement for infection were identified in a large administrative database. Morbidity and mortality rates were assessed for the 90-day postoperative period and readmission rates were assessed at 30 days postoperatively. These outcomes were then compared with those after coronary artery bypass grafting, carotid endarterectomy, prostatectomy, pancreatoduodenectomy (Whipple procedure), and kidney transplant. ResultsImplant removal and spacer placement for THA periprosthetic joint infection (n = 10,386) had a 30-day readmission rate of 11.1% and 90-day mortality rate of 2.6%. Major complications were seen in 15.3% patients. Postoperative morbidity was often higher in these patients when compared with other procedures studied. Ninety-day mortality rates were significantly higher compared with carotid endarterectomy, prostatectomy, and kidney transplant (odds ratio [ORs] between 2.1 and 12.5; P < .0001). Readmission rates at 30 days were significantly higher than all other groups including coronary artery bypass grafting and Whipple (ORs between 1.4 and 8.2; P < .0001). ConclusionRemoval of an infected THA with spacer placement is a high-risk surgery. This large study that includes over 10,000 patients helps quantify the risks of readmission, morbidity, and mortality. The rates of adverse outcomes are higher than those for many nonorthopedic operations typically considered to be major surgery.

Long-Term Outcomes of Permanent Cement Spacers in the Infected Foot

When osteomyelitis occurs in the infected foot, cement spacers have been used as a limb salvage tool. The aim of the present study was to assess the longevity and outcomes in high-risk, low-demand patients who have undergone resection of bone and subsequent placement of permanent antibiotic-eluting cement spacers in the foot. A retrospective review case series of 30 patients who had undergone placement of a permanent antibiotic-eluting cement spacer in the foot were evaluated for retention, spacer exchange, removal, amputation, and functional status. The minimum follow-up time for inclusion was 12 months. Two thirds of all patients had successful spacers (n = 20) that were either retained (n = 14) or successfully exchanged (n = 6). One third of all patients experienced spacer failure (n = 10) and required removal. Of the 10 patients requiring spacer removal, 4 underwent removal with subsequent arthrodesis and 6 underwent removal with subsequent pseudoarthrosis. Also, 8 of these patients (26.7%) required partial foot amputation of the ipsilateral foot. These amputations were not directly related to the use or removal of the spacer. The average time to spacer removal or partial amputation was 20.9 (range 0.2 to 60.9) months. The longest retained spacer in the foot was 76 months at the last follow-up visit. The longest exchanged spacer at the last follow-up visit was 111 months. All surviving patients were ambulatory at the last follow-up visit.