Ventriculo-gallbladder shunt: case series and literature review

BACKGROUND

The ventriculoperitoneal shunt (VPS) is the gold-standard surgical technique to treat hypertensive hydrocephalus; however, it may fail in 20 to 70% of cases. The present study shows an alternative for patients with contraindications to VPS.

METHODS

A case series of nine patients. The medical records of all patients under 17 years of age who underwent ventriculo-gallbladder (VGB) shunt at a pediatric hospital from January 2014 to October 2022 were reviewed.

RESULTS

There were 6 (66.7%) males and 3 (33.3%) females. The average age of 73.6 months or 6.1 years at the time of surgery. They had undergone, on average, 5.1 VPS reviews before the VGB shunt. Five (55.5%) had complications of VGB shunt: infection (11.1%), atony (11.1%), hypodrainage (11.1%), and ventriculoenteric fistula (22.2%); all these patients got better at surgical reapproach, and in two of them, the VGB shunt was re-implanted.

CONCLUSION

This case series shows a lower risk of death and a similar risk of complications compared to other alternative shunts. This article spotlighted VGB as a viable alternative when VPS fails or has contraindications.

Severe Hemodynamic Collapse During Humerus Stabilization with Photodynamic Implant: A Report of Two Cases

CASE

We present 2 cases of severe hemodynamic collapse during prophylactic stabilization of impending pathologic humerus fractures using a photodynamic bone stabilization device. Both events occurred when the monomer was infused under pressure into a balloon catheter.

CONCLUSION

We suspect that an increase in intramedullary pressure during balloon expansion may cause adverse systemic effects similar to fat embolism or bone cement implantation syndrome. Appropriate communication with the anesthesia team, invasive hemodynamic monitoring, and prophylactic vent hole creation may help mitigate or manage these adverse systemic effects.

Similar complications, implant survival, and function following modular prosthesis and allograft-prosthesis composite reconstructions of the proximal femur for primary bone tumors: a systematic review and meta-analysis

PURPOSE

There is a lack of consensus regarding the best type of reconstruction of the proximal femur following bone tumor resection. The objective of this study was to analyze the complication risks, implant survival, and functional outcomes following modular prosthesis (MP) and allograft-prosthesis composite (APC) reconstruction of the proximal femur after primary bone tumor resections.

METHODS

We performed a search in the PubMed and Scopus libraries, obtaining 1 843 studies. We included studies reporting functional outcomes, complications, and implant survival of proximal femur reconstruction with MP or APC following primary bone tumor resection with a 2-year minimum follow-up. We excluded studies analyzing metastatic patients or studies with pooled data in which it was impossible to separate the data of patients with primary bone tumors from those with bone metastases.

RESULTS

We analyzed 18 studies (483 patients) reporting on 234 (48%) patients with MP reconstruction and 249 (52%) patients with APC reconstruction. The risk of complications was similar in patients with MP reconstruction (29%; 95% CI [0.11; 0.47]) and APC reconstruction (36%; 95% CI [0.24; 0.47]) (p = 0.48). Implant survival following MP reconstruction ranged from 81 to 86% at 5 years, 75 to 86% at 10 years, and 82% at 15 years. Implant survival following APC reconstruction ranged from 86 to 100% at 5 years and 86% at 10 years, and 86% at 15 years. Functional outcomes following MP reconstruction and APC reconstruction ranged from 24.0 to 28.3 and from 21.9 to 27.8, respectively.

CONCLUSION

Patients with primary bone tumor of the proximal femur who underwent MP or APC reconstruction seem to have similar complication risks, implant survival, and functional outcomes.

Brain-implanted conductors amplify radiofrequency fields in rodents: Advantages and risks

Over the past few decades, daily exposure to radiofrequency (RF) fields has been increasing due to the rapid development of wireless and medical imaging technologies. Under extreme circumstances, exposure to very strong RF energy can lead to heating of body tissue, even resulting in tissue injury. The presence of implanted devices, moreover, can amplify RF effects on surrounding tissue. Therefore, it is important to understand the interactions of RF fields with tissue in the presence of implants, in order to establish appropriate wireless safety protocols, and also to extend the benefits of medical imaging to increasing numbers of people with implanted medical devices. This study explored the neurological effects of RF exposure in rodents implanted with neuronal recording electrodes. We exposed freely moving and anesthetized rats and mice to 950 MHz RF energy while monitoring their brain activity, temperature, and behavior. We found that RF exposure could induce fast onset firing of single neurons without heat injury. In addition, brain implants enhanced the effect of RF stimulation resulting in reversible behavioral changes. Using an optical temperature measurement system, we found greater than tenfold increase in brain temperature in the vicinity of the implant. On the one hand, our results underline the importance of careful safety assessment for brain-implanted devices, but on the other hand, we also show that metal implants may be used for neurostimulation if brain temperature can be kept within safe limits.

A pilot study of mitochondrial response to an in vivo prosthetic joint Staphylococcus aureus infection model

Prosthetic joint infections (PJI) are associated with orthopaedic morbidity and mortality. Mitochondria, the "cell's powerhouses," are thought to play crucial roles in infection response and in increased risk of sepsis mortality. No current research discusses PJI's effect on mitochondrial function and a lack of understanding of immune-infection interactions potentially hinders patient care. The purpose of this pilot study was to evaluate the impact of simulated PJI on local tissue mitochondrial function. Using an established prosthetic implant-associated in vivo model, tissues were harvested from the surgical limb of a methicillin-sensitive Staphylococcus aureus implant-associated infection group (n = 6) and compared to a noninfected group (n = 6) at postoperative day (POD) 21. Using mitochondrial coupling assays, oxygen consumption rate and extracellular acidification rate were assessed in each group. Electron flow through mitochondrial complexes reflected group activity. Electron Paramagnetic Resonance (EPR) spectrometry measured the oxidizing potential of serum samples from infected versus noninfected groups. On POD21, colony-forming units per gram of tissue showed 5 × 109 in the infected group and 101 in the noninfected group (p < 0.0001). Maximal respiration and oxygen consumption due to adenosine triphosphate synthesis were significantly lower in isolated mitochondria from infected limbs (p = 0.04). Both groups had similar complex I, III, IV, and V activity (p > 0.1). Infected group EPR signal intensity reflecting reactive oxygen species levels was 1.31 ± 0.30 compared to 1.16 ± 0.28 (p = 0.73) in the noninfected group. This study highlights PJI's role in mammalian cell mitochondrial dysfunction and oxidative tissue damage, which can help develop interventions to combat PJI.

Glaucoma after penetrating keratoplasty and keratoprosthesis

PURPOSE

To compare visual and glaucoma outcomes in patients with known glaucoma after a penetrating keratoplasty (PKP) or a Boston Keratoprosthesis Type 1 (KPro) as a second corneal replacement procedure.

DESIGN

Retrospective interventional case series.

PARTICIPANTS

Charts of 141 eyes that underwent either a PKP or KPro at the Centre hospitalier de l'Université de Montréal after one failed PKP from 2008 to 2020 were reviewed. Forty-six eyes with preoperative glaucoma were included.

METHODS

Data collected included demographics, indication for the initial surgery, best corrected visual acuity (BCVA), concurrent ocular disorders, number of glaucoma medications, need for glaucoma surgery, cup-to-disc ratios (CDRs), mean RNFL thickness, and visual field (VF) characteristics. Primary outcomes were glaucoma progression trends. Secondary outcomes were visual outcomes and need for additional procedures.

RESULTS

Mean follow-up was 4.7 years for the PKP and 7.3 for the KPro group (P<0.007). 30.6% of PKP compared to 70.5% of KPro patients were diagnosed with glaucoma preoperatively. Glaucoma worsened similarly in both groups; this is based on an analysis of the number of glaucoma medications, CDR, need for glaucoma surgery, and characteristic VF changes. Patients in the PKP group required significantly more regrafts than patients in the KPro group (31.8 vs. 8.3%; P=0.045).

CONCLUSIONS

A preoperative diagnosis of glaucoma does not preclude KPro implantation. In glaucomatous eyes, the disease progressed similarly in both groups. Since both procedures increase the risk of worsening glaucoma, close follow-up is recommended. KPro may decrease the need for further corneal transplantation surgery.

The Implant-Induced Foreign Body Response Is Limited by CD13-Dependent Regulation of Ubiquitination of Fusogenic Proteins

Implanted medical devices, from artificial heart valves and arthroscopic joints to implantable sensors, often induce a foreign body response (FBR), a form of chronic inflammation resulting from the inflammatory reaction to a persistent foreign stimulus. The FBR is characterized by a subset of multinucleated giant cells (MGCs) formed by macrophage fusion, the foreign body giant cells (FBGCs), accompanied by inflammatory cytokines, matrix deposition, and eventually deleterious fibrotic implant encapsulation. Despite efforts to improve biocompatibility, implant-induced FBR persists, compromising the utility of devices and making efforts to control the FBR imperative for long-term function. Controlling macrophage fusion in FBGC formation presents a logical target to prevent implant failure, but the actual contribution of FBGCs to FBR-induced damage is controversial. CD13 is a molecular scaffold, and in vitro induction of CD13KO bone marrow progenitors generates many more MGCs than the wild type, suggesting that CD13 regulates macrophage fusion. In the mesh implant model of FBR, CD13KO mice produced significantly more peri-implant FBGCs with enhanced TGF-β expression and increased collagen deposition versus the wild type. Prior to fusion, increased protrusion and microprotrusion formation accompanies hyperfusion in the absence of CD13. Expression of fusogenic proteins driving cell-cell fusion was aberrantly sustained at high levels in CD13KO MGCs, which we show is due to a novel CD13 function, to our knowledge, regulating ubiquitin/proteasomal protein degradation. We propose CD13 as a physiologic brake limiting aberrant macrophage fusion and the FBR, and it may be a novel therapeutic target to improve the success of implanted medical devices. Furthermore, our data directly implicate FBGCs in the detrimental fibrosis that characterizes the FBR.

Submuscular Buttock Augmentation With Silicone Implants in 80 Female Patients

BACKGROUND

Over the past 4 decades, gluteal augmentation has increased enormously in popularity, and numerous techniques have been developed to provide patients with the best possible outcomes. The submuscular technique has been shown to be a reliable option for a broad cohort of patients.

OBJECTIVES

The main objective of this retrospective study was to describe the characteristics and clinical outcomes of a group of patients who underwent gluteal augmentation by the submuscular technique.

METHODS

A retrospective analysis was conducted on 80 female patients who underwent submuscular gluteal augmentation with silicone implants between August 2019 and May 2022. All of the patients were operated on by the authors of the present study.

RESULTS

Information about patient demographics, implants, complications, and treatments was analyzed. Moreover, the satisfaction of the patients was assessed by means of a short survey. The most frequent complication was wound dehiscence. Only 7 patients required surgical revisions, and 2 required isolated antibiotic therapy. All complications were effectively addressed and no implants had to be removed. Furthermore, the retrospective analysis revealed a noteworthy association between the size of the implant and the occurrence of complications.

CONCLUSIONS

The submuscular method provides the best aesthetic results and adequate safety for patients. It significantly minimizes the possibility of complications, such as fluid collection due to muscle fiber dissection or implant exposure/extrusion.

LEVEL OF EVIDENCE: 4

Incidence, impact and predictors of residual device patency after left atrial appendage closure with the LACbes device

BACKGROUND

The residual device patency (RDP) after left atrial appendage closure (LAAC) with the LACbes device has not been specifically explored in atrial fibrillation (AF) patients. This study aims to explore the incidence, impact and predictors of RDP detected by cardiac computed tomography angiography (CCTA) post LAAC.

METHODS

AF patients implanted with the LACbes device were prospectively enrolled. CCTA device surveillance was performed at 3 months post-procedure. Major adverse events (MAEs), including stroke/transient ischemic attack, major bleeding and all-cause death, were evaluated.

RESULTS

Among 141 patients with CCTA surveillance, 56 (39.7%) showed no visible leak and 85 (60.3%) showed RDP. During the median follow-up of 443 [232, 706] days, the presence of RDP was not associated with an increased risk of MAEs (adjusted hazard ratio [HR]: 4.07, 95% confidence interval [CI]: 0.49-34.24, p = 0.196), while peri-device leak (PDL) at the lobe was associated with heightened risks of MAEs (adjusted HR: 6.85, 95% CI: 1.62-28.89, p = 0.009). In patients with PDL at the lobe, antiplatelet after 6 months (HR: 0.20, 95% CI: 0.05-0.91, p = 0.038) was independent protective predictor of MAEs. Besides, current smoking (odds ratio [OR]: 7.52, 95% CI: 2.68-21.08, p < 0.001) and maximum diameter of LAA orifice (OR: 1.16, 95% CI: 1.00-1.34, p = 0.048) were independent predictors of PDL at the lobe.

CONCLUSIONS

Presence of PDL at the device lobe detected by CCTA at 3-month post LAAC with LACbes is associated with unfavorable prognosis in AF patients.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03788941.

Instrumentation failure following pediatric spine deformity growth-sparing surgery using traditional growing rods or vertical expandable prosthetic titanium ribs

BACKGROUND

Instrumentation failure (IF) is a major complication associated with growth-sparing surgery for pediatric spinal deformities; however, studies focusing on IF following each surgical procedure are lacking. We aimed to evaluate the incidence, timing, and rates of unplanned return to the operating room (UPROR) associated with IF following each surgical procedure in growth-sparing surgeries using traditional growing rods (TGRs) and vertical expandable prosthetic titanium ribs (VEPTRs).

METHODS

We reviewed 1,139 surgical procedures documented in a Japanese multicenter database from 2015 to 2017. Of these, 544 TGR and 455 VEPTR procedures were included for evaluation on a per-surgery basis. IF was defined as the occurrence of an implant-related complication requiring revision surgery.

RESULTS

The surgery-based incidences of IF requiring revision surgery in the TGR and VEPTR groups were 4.3% and 4.0%, respectively, with no significant intergroup difference. Remarkably, there was a negative correlation between IF incidence per surgical procedure and the number of lengthening surgeries in both groups. In addition, rod breakage in the TGR group and anchor-related complications in the VEPTR group tended to occur relatively early in the treatment course. The surgery-based rates of UPROR due to IF in the TGR and VEPTR groups were 2.0% and 1.5%, respectively, showing no statistically significant difference.

CONCLUSIONS

We found that IF, such as anchor related-complications and rod breakage, occurs more frequently earlier in the course of lengthening surgeries. This finding may help in patient counseling and highlights the importance of close postoperative follow-up to detect IF and improve outcomes.

[Growth-preserving instrumentation for early onset scoliosis]

OBJECTIVE

Early onset scoliosis is defined as a spinal deformity originating in the first 10 years of life. Growth-preserving spinal instrumentation has therefore been designed to preserve growth of spine and chest wall and lungs to avoid serious pulmonary complications after early spine fusion. Indications, surgical technique and results of the vertical expandable prosthetic titanium rib (VEPTR) technique, traditional growing rods (TGR), and magnetically controlled growing rods (MCGR) will be described.

INDICATIONS

Indications for VEPTR are so-called mixed congenital deformities (type 3) associated with vertebral malformations in association with chest wall deformities, especially fused ribs. There are also indications for neuromuscular or syndromic early onset scoliosis with bilateral rib-to-ilium constructs. However, most of those deformities are currently treated with either GR or MCGR in most centers. GR and MCGR are currently the treatment of choice for the majority of early onset scoliosis.

CONTRAINDICATIONS

There is no indication for growth-preserving strategies if the patients are mature or there is only little growth remaining. In these cases, final fusion should be performed.

SURGICAL TECHNIQUE

While the VEPTR technique involves an extensive approach with muscular dissections to the thoracic cage including rib osteotomies and thoracotomies, treatment with TGR or MCGR is minimally invasive, only exposing proximal and distal anchor points, leaving most of the spine including the apex undisturbed.

POSTOPERATIVE MANAGEMENT

Early mobilization is usually possible after 24-48 h. Braces may have to be prescribed for patients with osteopenia, noncompliance, or a risk to fall.

RESULTS

Since 2005, more than 200 patients were treated with the VEPTR technique, more than 200 patients with the MCGR technique, and about 30 patients with the TGR technique in our department. Complication rates are high with all techniques including the law of diminishing returns, autofusion, bone anchor-related complications like loosening or migration of implants, failure to distract and proximal junctional kyphosis. In our own series of 13 patients below age 3 years, VEPTR proved to be effective for mixed deformities. In other studies, we were able to show that physiological growth with MCGR can be maintained for 2-3 years but spinal growth declines after that period with acceptable complications. Complication rates in most studies are lower with MCGR compared to TGR and VEPTR. Therefore, it is currently the treatment of choice for most early onset scoliosis patients.

Custom Iris Prosthesis for Subtotal Traumatic Aniridia From Combat Ocular Trauma

Traumatic aniridia from combat ocular trauma can cause visual disability. A 41-year-old male Army Veteran was referred for evaluation of light sensitivity and glare secondary to subtotal traumatic aniridia of his left eye from an improvised explosive device blast. A custom-made artificial iris prosthesis was implanted in the ciliary sulcus and secured using Gore-Tex sutures. After surgery, the patient reported improvement of his light sensitivity and quality of life. The custom iris prosthesis is a surgical option for visual disability resulting from traumatic aniridia from combat ocular trauma.

A review of wear debris in thumb base joint implants

AIM

Polymers and metals, such as polyethylene (PE) and cobalt chrome (CoCr), are common materials used in thumb-based joint implants, also known as CMC (Carpometacarpal) arthroplasty. The purpose of this review was to investigate the reported failure modes related to wear debris from these type of materials in CMC implants. The impact of wear debris on clinical outcomes of CMC implants was also examined. Potential adverse wear conditions and inflammatory particle characteristics were also considered.

METHOD

A literature search was performed using PRISMA guidelines and 55 studies were reviewed including 49 cohort studies and 6 case studies. Of the 55 studies, 38/55 (69%) focused on metal-on-polyethylene devices, followed by metal-on-metal (35%), and metal-on-bone (4%).

RESULTS

The summarized data was used to determine the frequency of failure modes potentially related to wear debris from metals and/or polymers. The most commonly reported incidents potentially relating to debris were implant loosening (7.1%), osteolysis (1.2%) and metallosis (0.6%). Interestingly the reported mechanisms behind osteolysis and loosening greatly varied. Inflammatory reactions, while rare, were generally attributed to metallic debris from metal-on-metal devices. Mechanisms of adverse wear conditions included implant malpositioning, over-tensioning, high loading for active patients, third-body debris, and polyethylene wear-through. No specific examination of debris particle characterization was found, pointing to a gap in the literature.

CONCLUSION

This review underscores the types of failure modes associated with wear debris in CMC implants. It was found that failure rates and adverse wear conditions of CMC implants of any design are low and the exact relationship between wear debris and implant incidences, such as osteolysis and loosening remains uncertain. The authors note that further research and specific characterization is required to understand the relationship between debris and implant failure.

Outcomes of culture-negative or -positive periprosthetic joint infections: A systematic review and meta-analysis

OBJECTIVES

This study overviewed the current database of studies on periprosthetic joint infections (PJIs) to compare outcomes and antibiotic side effects in culture-negative or culture-positive PJIs and assess treatment options for culture-negative PJIs.

PATIENTS AND METHODS

A systematic review and meta-analysis was undertaken using studies published before July 2022 in MEDLINE, EMBASE, and Cochrane Library. All studies comparing treatment of culture-negative or -positive PJIs were included. Afterward, the infection control rate, periprosthetic or spacer fracture, hip joint or spacer dislocation, and antibiotic side effects in different treatment methods of PJI were analyzed.

RESULTS

Eleven studies involving 1,747 patients were included. Most studies clearly defined the infection control criteria: no pain or swelling, no wound drainage, normal serology, and normal radiographic findings. Patients were followed until treatment failure, death, or until the last clinical visit without evidence of treatment failure. The two types of PJIs did not differ significantly in infection control rates (culture-negative PJI 79.2% vs. culture-positive PJI 76.6%; odds ratio [OR]=1.20, 95% confidence interval [CI]: 0.84 to 1.70), either after all types of surgical treatment or after two-stage revision arthroplasty (OR=1.12, 95% CI: 0.72 to 1.75), single-stage revision arthroplasty (OR=0.51, 95% CI: 0.19 to 1.37), or debridement, antibiotics, and implant retention (OR=0.88, 95% CI: 0.50 to 1.54). Similarly, we did not find differences in periprosthetic or spacer fracture and hip joint or spacer dislocation. For culture-negative PJIs, the infection control rate was 85.2% after two-stage revision arthroplasty, 90.6% after single-stage revision arthroplasty, and 69.7% after debridement, antibiotics, and implant retention. Data pooled from three studies showed higher incidence of antibiotic side effects for culture-negative PJIs.

CONCLUSION

The clinical outcomes of one-stage revision and two-stage revision are comparable. Therefore, both of them can be considered in surgical treatment for culture-negative PJIs. In addition, limited data showed a higher incidence of antibiotic side effects in culture-negative PJIs.

Biomaterials in the clinical treatment of lymphedema-a systematic review

OBJECTIVE

Lymphedema is a chronic condition caused by impaired lymphatic fluid drainage, resulting in progressive edema. The current mainstay of lymphedema therapy consists of conservative therapy and surgical therapy. In this systematic review, we investigated the novel role of biomaterials in clinical lymphedema therapy and assessed their objective outcomes and the complication rate associated with their use.

METHODS

Studies were identified through systematic review using the Embase and PubMed/MEDLINE databases. Only original articles reporting the use of biomaterials for clinical lymphedema therapy were included. The primary outcome measure was the objective reduction in limb volume after biomaterial use. The secondary outcome measure was the assessment of biomaterial safety.

RESULTS

A total of 354 articles were identified in the first search, of which 10 met our inclusion criteria. These articles described the use of two biomaterials, nanofibrillar collagen scaffolds (NCSs) and silicone tubes (STs), for the treatment of lymphedema. NCS implantation showed an average excess limb volume reduction of 1% to 10.7% and clear evidence of lymphangiogenesis on imaging. No complications were 7documented after NCS implantation. ST implantation showed an average limb volume reduction of 700 to 887 mL and limb circumference reduction of 3.1 to 8 cm in patients with advanced stage lymphedema. Of 177 patients treated with ST implantation, only 11 (6.2%) developed local inflammation.

CONCLUSIONS

Both NCS and ST implantation showed promising limb volume reduction; however, with the scarce literature available, additional research is needed to determine their effectiveness. Both demonstrated good safety profiles, with no complications after NCS implantation and a complication rate equivalent to other similar implants for ST implantation.

The effect of periprosthetic bone loss on the failure risk of tibial total knee arthroplasty

The effect of long-term periprosthetic bone loss on the process of aseptic loosening of tibial total knee arthroplasty (TKA) is subject to debate. Contradicting studies can be found in literature, reporting either bone resorption or bone formation before failure of the tibial tray. The aim of the current study was to investigate the effects of bone resorption on failure of tibial TKA, by simulating clinical postoperative bone density changes in finite element analysis (FEA) models and FEA models were created of two tibiae representing cases with good and poor initial bone quality which were subjected to a walking configuration and subsequently to a traumatic stumbling load. Bone failure was simulated using a crushable foam model incorporating progressive yielding. Repetitive loading under a level walking load did not result in failure of the periprosthetic bone in neither the good nor poor bone quality tibia at the baseline bone densities. When applying a stumble load, a collapse of the tibial reconstruction was noticed in the poor bone quality model. Incorporating postoperative bone loss led to a significant increase of the failure risk, particularly for the poor bone quality model in which subsidence of the tibial component was substantial. Our results suggest bone loss can lead to an increased risk of a collapse of the tibial component, particularly in case of poor bone quality at the time of surgery. The study also examined the probability of medial or lateral subsidence of the implant and aimed to improve clinical implications. The FEA model simulated plastic deformation of the bone and implant subsidence, with further validation required via mechanical experiments.

The Role of Revision Total Joint Arthroplasty for Periprosthetic Fractures With Unstable Implants

The management of periprosthetic fractures with unstable prosthetic implants is a challenging and commonly encountered problem. It is important to address the many current issues and controversies regarding the treatment of periprosthetic fractures with revision total joint arthroplasty. Key strategies to optimize surgical decision making around the use of arthroplasty and management of complications following these complex injuries will be addressed.

Pathophysiology of the Toxic Effects in Metallic Implants

Implants play a very crucial role in modern era of medicine and address several needs in all the medical specialties. Both essential and nonessential metals released from implants at high concentrations can impair biological functions and result in toxicity involving multiple systems of the body. Furthermore, the toxicity information is typically based on exposure through dietary intake and/or occupational/environmental exposure but, since the in vivo implant environment and its composition is different or unknown, individual implants toxic effects needs to be elaborated. Several clinical and nonclinical assessment tools are advised by FDA to evaluate biocompatibility issues, such as risk of immunological response, tissue destruction or overgrowth, and other adverse reactions. The Center for Devices and Radiological Health (CDRH) Biocompatibility Guidelines state that biocompatibility end points caused by metallic implants includes cytotoxicity, sensitization, acute and chronic systemic toxicity, pyrogenicity, genotoxicity, carcinogenicity, implantation, hemocompatibility, reproductive abnormalities, developmental toxicity and biodegradation. Exposure to metal ions which acts as haptens can lead to both local and systemic hypersensitivity reactions which are generally believed to be a Type IV (delayed hypersensitivity) response. Currently, most assessment tools of implant associated hypersensitivity are based on skin sensitization which provides further scopes for research in understanding patient specific immune response causing systemic hypersensitivity.

Efficacy and Safety of Expanded Polytetrafluoroethylene Implantation in the Correction of Long-Term Posttraumatic Enophthalmos

SUMMARY

Long-term enophthalmos is a common orbital fracture sequela. Various autografts and alloplastic materials have been studied in posttraumatic enophthalmos repair. However, expanded polytetrafluoroethylene (ePTFE) implantation in late enophthalmos repair has rarely been reported. The authors report novel use of ePTFE for late posttraumatic enophthalmos repair. This retrospective study included patients with posttraumatic long-term enophthalmos who underwent hand-carved ePTFE intraorbital implantation for enophthalmos correction. Computed tomography data were collected preoperatively and at follow-up. The volume of ePTFE, the degree of proptosis (DP), and enophthalmos were measured. Postoperative and preoperative DP and enophthalmos were compared using the paired t test. The correlation between ePTFE volume and DP increment was established using linear regression. Complications were identified by chart review. From 2014 to 2021, 32 patients were included, with a mean follow-up of 19.59 months. The mean volume of implanted ePTFE was 2.39 ± 0.89 mL. After surgery, the DP of the affected globe improved significantly, from 12.75 ± 2.12 mm to 15.06 ± 2.50 mm ( P < 0.0001). A significant linear correlation was found between ePTFE volume and DP increment ( P < 0.0001). Enophthalmos was substantially ameliorated from 3.35 ± 1.89 mm to 1.09 ± 2.07 mm ( P < 0.0001). Twenty-five patients (78.23%) had postoperative enophthalmos of less than 2 mm. Infection and implant dislocation were not observed. The authors concluded that ePTFE intraorbital implantation exhibited long-term efficacy and safety for late posttraumatic enophthalmos repair and represents an effective and predictable alternative.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Adverse reactions to cosmetic implants after COVID-19 vaccination: A literature review

BACKGROUND

As the world's population of people vaccinated with the COVID-19 vaccine increases, adverse reactions are increasingly being reported. There have been progressive reports of the effects of COVID-19 vaccination on cosmetic fillers or prostheses, but they have not been reviewed based on their clinical morphologic patterns. This article reviewed the progress of research on adverse reactions to cosmetic implants after COVID-19 vaccination.

METHODS

We researched the English-language literature up to October 15, 2022, using predefined keywords to identify relevant studies about adverse reactions to cosmetic implants after the COVID-19 vaccination, collecting patient characteristics, implant type, the time interval between vaccination and implantation or injection, time of onset, symptoms, treatments, and outcomes.

RESULTS

Among the adverse reactions to implants associated with COVID-19 vaccination, we distinguished between (1) injectable fillers and (2) surgical prosthetic implants. The most common adverse reactions were at the site of hyaluronic acid injection and breast prosthesis after Pfizer vaccination, mainly DIRs, and mainly manifested as edema, rash, fever, and capsular contracture. This paper also reported the possible causes, treatments of DIRs, and limitations of current studies.

CONCLUSIONS

In this article, we attempted to investigate and discuss all the adverse reactions of cosmetic implants related to COVID-19 vaccination in the current literature, to unmask these reactions and make a more accurate assessment of vaccine safety.

Biologic versus synthetic prosthesis for chest wall reconstruction: a matched analysis

OBJECTIVES

The aim of this study was to compare postoperative outcomes between biologic and synthetic reconstructions after chest wall resection in a matched cohort.

METHODS

All patients who underwent reconstruction after full-thickness chest wall resection from 2000 to 2022 were reviewed and stratified by prosthesis type (biologic or synthetic). Biologic prostheses were of biologic origin or were fully absorbable and incorporable. Integer matching was performed to reduce confounding. The study end point was surgical site complications requiring reoperation. Multivariable analysis was performed to identify associated risk factors.

RESULTS

In total, 438 patients underwent prosthetic chest wall reconstruction (unmatched: biologic, n = 49; synthetic, n = 389; matched: biologic, n = 46; synthetic, n = 46). After matching, the median (interquartile range) defect size was 83 cm2 (50-142) for the biologic group and 90 cm2 (48-146) for the synthetic group (P = 0.97). Myocutaneous flaps were used in 33% of biologic reconstructions (n = 15) and 33% of synthetic reconstructions (n = 15) in the matched cohort (P = 0.99). The incidence of surgical site complications requiring reoperation was not significantly different between biologic and synthetic reconstructions in the unmatched (3 [6%] vs 29 [7%]; P = 0.99) and matched (2 [4%] vs 4 [9%]; P = 0.68) cohorts. On the multivariable analysis, operative time [adjusted odds ratio (aOR) = 1.01, 95% confidence interval (CI), 1.00-1.01; P = 0.006] and operative blood loss (aOR = 1.00, 95% CI, 1.00-1.00]; P = 0.012) were associated with higher rates of surgical site complications requiring reoperation; microvascular free flaps (aOR = 0.03, 95% CI, 0.00-0.42; P = 0.024) were associated with lower rates.

CONCLUSIONS

The incidence of surgical site complications requiring reoperation was not significantly different between biologic and synthetic prostheses in chest wall reconstructions.

[Long-term visual outcomes of Boston type I keratoprosthesis in Canada]

BACKGROUND/PURPOSE

To evaluate long-term visual outcomes of Boston type I keratoprosthesis (KPro) surgery and identify risk factors for visual failure.

METHODS

Single surgeon retrospective cohort study including 85 eyes of 74 patients who underwent KPro implantation to treat severe ocular surface disease, including limbal stem cell deficiency, postinfectious keratitis, aniridia and chemical burns. Procedures were performed at the Centre hospitalier de l'Université de Montréal from October 2008 to May 2012. All patients with at least 5 years of follow-up were included in the analysis, including eyes with repeated KPro. Main outcome measures were visual acuity (VA), visual failure, defined as a sustained VA worse than the preoperative VA, postoperative complications, and device retention.

RESULTS

Mean follow-up was 7.2±1.3 years (±SD). Mean VA was 2.1±0.7 (logarithm of minimal angle resolution) preoperatively and 1.9±1.2 at last follow-up. In total, 2.4% of patients had VA better than 20/200 preoperatively vs. 36.5% at last follow-up. Maintenance of improved postoperative VA was seen in 61.8% of eyes at 7 years. Preoperative factors associated with visual failure were known history of glaucoma (HR=2.7 [1.2 to 5.9], P=0.02) and Stevens-Johnson syndrome (HR=7.3 [2.5 to 21.4], P<0.01). Cumulative 8-year complication rates were 38.8% retroprosthetic membrane formation, 25.9% hypotony, 23.5% new onset glaucoma, 17.6% retinal detachment, 8.2% device extrusion and 5.9% endophthalmitis. The majority (91.8%) of eyes retained the device 8 years after implantation.

CONCLUSION

Nearly two-thirds of patients exhibited improved VA 7 years after KPro implantation. Preoperative risk factors for visual failure were known glaucoma and Stevens-Johnson syndrome.

Rat model of recalcitrant prosthetic joint infection using biofilm inocula

Prosthetic joint infection (PJI) is a rare but devastating complication of joint arthroplasty. Biofilm formation around the prosthesis confers tolerance to antibiotics so that treatment is challenging. Most animal models of PJI use planktonic bacteria to establish the infection which fails to reproduce the pathology of chronic infection. We aimed to establish a rat model of Staphylococcus aureus PJI in male Sprague-Dawley rats using biofilm inocula and demonstrate its tolerance to frontline antibiotics. Pilot studies indicated that infection could be introduced to the knee joint by a biofilm-coated pin but that handling the prosthetic without disturbing the biofilm was difficult. We, therefore, developed a pin with a slotted end and used a miniature-biofilm reactor to develop mature biofilm in this niche. These biofilm-laden pins consistently produced infection of the bone and joint space. Treatment with high dose cefazolin, 250 mg/kg, starting the day of surgery reduced or cleared pin-adherent bioburden within 7 days, however when escalation from 25 to 250 mg/kg cefazolin treatment was delayed for 48 h, rats were unable to clear the infection. To track infections, we used bioluminescent bacteria, however, the bioluminescent signal did not accurately track the degree of infection in the bone and joint space as the signal did not penetrate the bone. In conclusion, we demonstrate that using a custom prosthetic pin, we can generate biofilm in a specific niche using a novel bioreactor setup and initiate a rat PJI that rapidly develops tolerance to supra-clinical doses of cefazolin.

Neuronavigated foraminoplasty, shunt removal, and endoscopic third ventriculostomy in a 54-year-old patient with third shunt malfunction episode: how I do it

BACKGROUND

The application of endoscopic third ventriculostomy (ETV) for the treatment of obstructive hydrocephalus in shunt malfunction represents a paradigm shift, as it allows hydrocephalus to be transformed from a chronic condition treated with an artificial device to a curable disease.

METHODS

We present a 54-year-old male with a diagnosis of idiopathic Sylvian aqueduct stenosis treated with shunt. The patient presented to our institution with symptoms of shunt malfunction and an increase in ventricular size on imaging, which was his third episode throughout his life. Through a right precoronal approach, with prior informed consent from the patient, we performed foraminoplasty, endoscopic third ventriculostomy, and finally removal of the shunt system.

CONCLUSION

ETV shows promise as a viable treatment option for shunt malfunction in noncommunicating obstructive hydrocephalic patients. Its potential to avoid VPS-related complications, preserve physiological CSF circulation, and provide an alternative drainage pathway warrants further investigation.

Management of Implant Extrusion following Thyroplasty for Vocal Fold Paralysis: A Case Report

The most widely used laryngeal surgery technique for patients with vocal fold paralysis is medialization thyroplasty. Materials such as Gore-Tex, silastic, and hydroxyapatite are often used, and the most worrisome possible complication is extrusion of the implant. A 36-year-old female patient with a history of pediatric cardiac surgery was diagnosed with left vocal cord paralysis after an episode of upper respiratory infection with a working diagnosis of subclinical left vocal cord paralysis following cardiac surgery. She underwent medialization thyroplasty with a Gore-Tex implant under local anesthesia. On the 21st postoperative day, she presented with sudden-onset hoarseness and dysphagia due to Gore-Tex implant extrusion. The implant was removed and augmentation of the left vocal cord with adipose tissue was performed. Only 14 cases of Gore-Tex implant extrusion have been described in the literature so far. The aim of this case report was not only to show one possible complication when using a Gore-Tex implant but also to present fat augmentation as one of the solutions for revision medialization and salvage treatment, with sustained long-term results.

Punctal Plug Granuloma After Blepharoplasty

This case report discusses a diagnosis of foreign body granuloma resulting from a punctal plug in a patient aged 66 years with chronic dry eye and a history of blepharoplasty.

Complications of Fat Grafting Versus Implants in Gluteal Augmentation: A Retrospective Review and Lessons Learnt

There have been various studies and literature reviews about gluteal augmentation, possibly due to the high complication rates associated with the procedure. But in the recent past, there has been extensive work in an effort to reduce the complications and various different methods have been developed for this purpose. This article brings to view the procedure followed in our surgery centre for fat grafting and implants for gluteal augmentation. We have compiled the complications we encountered with these procedures and the lessons we learnt to prevent them. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The one-step edge-to-edge technique in ventriculoperitoneal shunt

BACKGROUND

Subcutaneous tunneling of the distal catheter is a potentially risky part of ventriculoperitoneal shunt (VPS) insertion. We describe our institutional experience with a simple trick to improve functional and aesthetic results in VPS by reducing the distal catheter tunneling to a single passage.

MATERIALS AND METHODS

The one-step edge-to-edge technique has been performed in our institution over 14 years in 46 patients with a mean age of 63. 27 were female (58.7%). 7 patients suffered from post-traumatic hydrocephalus, 6 from normal pressure hydrocephalus, 15 from obstructive hydrocephalus and 18 from hydrocephalus secondary to subarachnoid hemorrhage. Operative blood loss varied from 20 to 40 cc.

RESULTS

No complication related to the modified tunneling technique were described except a transitory peripheral VII nerve palsy (2.2%). The absence of middle skin incision is appreciated by the patient, especially in young females that not presented scars at the level of the neckline.

CONCLUSION

Our technique is the first report of one step tunneling in adults. It reduces distal catheter tunneling time in VPS simplifying the procedure to a single step and using a simple reproducible trick.

Cerebrospinal fluid shunt malfunctions: A reflective review

PURPOSE

Pediatric hydrocephalus is a common and challenging condition. To date, the ventriculoperitoneal shunt (VPS) is still the main lifesaving treatment option. Nonetheless, it remains imperfect and is associated with multiple short- and long-term complications. This paper is a reflective review of the current state of the VPS, our knowledge gaps, and the future state of shunts in neurosurgical practice.

METHODS AND RESULTS

The authors' reflections are based on a review of shunts and shunt-related literature.

CONCLUSION

Overall, there is still an urgent need for the neurosurgical community to actively improve current strategies for shunt failures and shunt-related morbidity. The authors emphasize the role of collaborative efforts amongst like-minded clinicians to establish pragmatic approaches to avoid shunt complications.

Apnea management during WATCHMAN device deployment with apneic oxygenation: A case report of three cases

WATCHMAN is a percutaneous left atrial appendage closure device that is implanted in patients who are unsuitable for anticoagulation therapy for atrial fibrillation. During WATCHMAN implantation, inducing apnea in the patient is preferable to allow stable deployment. We present three cases in which apneic oxygenation was employed to maintain oxygenation during apnea, and oxygen reserve index (ORiTM) was measured to evaluate its safety and efficacy. Oxygen was administered continuously via the endotracheal tube during apnea. During all four apneic events in three patients (mean duration of 356 seconds), the ORi values maintained above 0.24, which is generally considered the threshold of partial pressure of arterial oxygen (PaO2) > 100 mmHg. Transcutaneous oxygen saturation and PaO2 remained above 99% and 300 mmHg, respectively. There were no respiratory or circulatory complications during or after the surgery.

Adverse Event Reporting of Commonly Used Gender-Specific Implantable Medical Devices in the United States

BACKGROUND

Evidence suggests that more women are harmed by implantable medical devices than men. It is unknown whether this difference includes gender-specific devices.

METHODS

In this study, we examine the differences in reported adverse events between 6 female- and 5 male-specific implantable devices from the Manufacturer and User Facility Device Experience (MAUDE) database from 1993 to 2018. Primary endpoints were injury type (life-threatening, disability, death) and the rate of device evaluation by the manufacturer. Proportions of valid entries across these variables were compared using either the Fisher exact test or χ2 test.

RESULTS

Female-specific devices had higher rates of life-threatening outcomes (1.6% versus 0.3%, P < 0.001), disabilities (5.0% versus 4.3%, P < 0.001), and deaths (0.6% versus 0.1%, P < 0.001) compared with the male-specific devices. Of the 8159 devices that were evaluated by the manufacturer, 56% were female specific while 44% were male specific. Female-specific devices were evaluated far less frequently by the manufacturer (4.5% versus 38.2%, P < 0.001).

CONCLUSIONS

Increased adverse events reports for female-specific devices and associated high-grade complications necessitates improved postmarket surveillance.

Subject-Specific Modeling of Implant Placement for Type I Thyroplasty Surgery

Type I thyroplasty is widely used to improve voice production in patients affected by unilateral vocal fold paralysis. Almost two-thirds of laryngologists report using Silastic® implants to medialize the vocal fold, with implant size, shape, and location determined experientially. However, post-surgical complications arising from this procedure (extrusion, migration, resizing) necessitate revision in 4.5-16% of patients. To improve initial surgical outcomes, we have developed a subject-specific modeling tool, PhonoSim, which uses model reconstruction from MRI scans to predict the optimal implantation location. Eleven vocal fold sample sides from eight larynges of New Zealand white rabbits were randomized to two groups: PhonoSim informed (n = 6), and control (no model guidance, n = 5). Larynges were scanned ex vivo in the abducted configuration using a vertical-bore 11.7 T microimaging system, and images were used for subject-specific modeling. The PhonoSim tool simulated vocal fold adduction for multiple implant location placements to evaluate vocal fold adduction at the medial surface. The best implant placement coordinates were output for the 6 samples in the PhonoSim group. Control placements were determined by the same surgeon based on anatomical landmarks. Post-surgical MRI scans were performed for all samples to evaluate medialization in implanted vocal folds. Results show that PhonoSim-guided implantation achieved higher vocal fold medialization relative to controls (28 to 55% vs. - 29 to 39% respectively, in the glottal area reduction), suggesting that this tool has the potential to improve outcomes and revision rates for type I thyroplasty.

How Often Do Complications and Mortality Occur After Operatively Treated Periprosthetic Proximal and Distal Femoral Fractures? A Register-based Study

BACKGROUND

The incidence of periprosthetic femoral fractures is increasing because of an increasing number of primary THAs and TKAs. High rates of complications and mortality are associated with periprosthetic fractures, but few studies have evaluated and compared the population-based incidences of these events after fractures.

QUESTIONS/PURPOSES

(1) What is the annual incidence of periprosthetic fractures treated with surgery in one hospital district in Finland? (2) How are those incidences changing over time? (3) What is the risk of complications, reoperations, and death after those injuries?

METHODS

This register-based study evaluated 2259 patients who underwent revision THA or TKA or any surgery for a femoral fracture between January 2004 and December 2016 at the only hospital in our district where these types of operations are performed. During the study period, the diagnosis and operation codes of the operated-on patients varied greatly, and they were somewhat inaccurate. We thus evaluated radiographs of all 2259 patients one by one, and created inclusion and exclusion criteria based on radiologic findings and medical records. Of those, 12% (279 of 2259) had periprosthetic fractures that met the inclusion criteria, and from these, we formed two study groups (periprosthetic proximal femur fractures, n = 171; periprosthetic distal femur fractures, n = 108). Eighty-eight percent (1980 of 2259) of the patients were excluded because they were treated for a condition other than periprosthetic femoral fracture. The follow-up period ended in December 2019 or at the time the patient died. To evaluate the population-based incidence, we drew the number of individuals with THA or TKA in the hospital district from the Finnish Arthroplasty Register and the Finnish Hospital Discharge Register. The characteristics of patients with operatively treated periprosthetic femoral fractures were evaluated in terms of age, gender, fracture type, implant type, and time from the index operation to periprosthetic fracture. The annual incidences of periprosthetic femoral fractures are summarized per 1000 person-years of individuals living with an implanted THA or TKA and per 100,000 individuals per year living in our hospital district. The risks of death, complications, and reoperations were evaluated for both groups, and comparisons were made in terms of patient characteristics.

RESULTS

The mean annual incidence of operatively treated periprosthetic proximal femur fractures per 1000 people living with THA implants was 2.3 ± 0.9 (95% confidence interval 1.8 to 2.7) per year, and for those with periprosthetic distal femur fractures with TKA implants, it was 1.3 ± 0.6 (95% CI 1.0 to 1.7). There was an increasing trend in the incidence of periprosthetic proximal femur fractures from 1.6 to 3.8 (95% CI 1.8 to 2.8) per 1000 arthroplasties, and it increased from 0.4 to 1.7 (95% CI 2.4 to 4.4) for periprosthetic distal femur fractures between 2004 and 2016. The mean population-based incidence of periprosthetic proximal femur fractures per 100,000 person-years was 5.3 ± 2.2 (95% CI 4.1 to 6.4) per year, and for periprosthetic distal femur fractures, it was 3.4 ± 1.7 (95% CI 2.5 to 4.4). The incidence of periprosthetic proximal femur fractures related to 100,000 person-years increased from 3.2 to 8.9 (95% CI 3.9 to 6.6), while the incidence of periprosthetic distal femur fractures increased from 1.3 to 4.4 (95% CI 2.4 to 4.8) during the study period. The cumulative incidence of major complications after periprosthetic proximal femur fracture was 8.8% at 1 year (95% CI 5.1% to 13.6%) and 12.3% at 10 years (95% CI 7.5% to 18.4%), and after periprosthetic distal femur fracture, it was 7.4% at 1 year (95% CI 3.5% to 13.4%) and 9.3% at 10 years (95% CI 4.7% to 15.7%). The cumulative incidence of reoperation after periprosthetic proximal femur fracture was 10.5% at 1 year (95% CI 6.5% to 15.7%) and 13.5% at 10 years (95% CI 8.9% to 19.1%), and for periprosthetic distal femur fracture, it was 8.3% at 1 year (95% CI 4.1% to 14.5%) and 13.8% at 10% years (95% CI 7.8% to 21.4%). The cumulative incidence of death after periprosthetic proximal femur fracture was 8.2% at 1 year (95% CI 4.7% to 12.9%) and 47.3% at 10 years (95% CI 38.1% to 55.9%), and after periprosthetic distal femur fractures, it was 14.8% at 1 year (95% CI 8.8% to 22.2%) and 67.8% at 10 years (95% CI 56.3% to 76.9%).

CONCLUSION

The increased use of THA and TKA has led to an increase in the incidence of operatively treated periprosthetic fractures, which means there will be more revisions in the future. Older age, frailty of these patients, and often-complicated fracture patterns are related to a high rate of complications, reoperations, and mortality. Healthcare systems must prepare for a large increase in revisions for periprosthetic fracture, which are morbid events for patients and costly ones for healthcare systems.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Indications and techniques for non-articulating spacers in massive bone loss following prosthetic knee joint infection: a scoping review

INTRODUCTION

Prosthetic joint infection (PJI) is a destructive complication of knee replacement surgery (KR). In two-stage revision a spacer is required to maintain limb length and alignment and provide a stable limb on which to mobilise. Spacers may be articulating or static with the gold standard spacer yet to be defined. The aims of this scoping review were to summarise the types of static spacer used to treat PJI after KR, their indications for use and early complication rates.

METHODS

We conducted a scoping review based on the Joanna Briggs Institute's "JBI Manual for Evidence Synthesis" Scoping review reported following Preferred Reporting Items for Systematic Review and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) checklist. MEDLINE, EMBASE and CINAHL were searched from 2005 to 2022 for studies on the use of static spacers for PJI after KR.

RESULTS

41 studies (1230 patients/knees) were identified describing 42 static spacer constructs. Twenty-three (23/42 [54.2%]) incorporated cement augmented with metalwork, while nineteen (19/42, [45.9%]) were made of cement alone. Spacers were most frequently anchored in the diaphysis (22/42, [53.3%]), particularly in the setting of extensive bone loss (mean AORI Type = F3/T3; 11/15 studies 78.3% diaphyseal anchoring). 7.1% (79 of 1117 knees) of static spacers had a complication requiring further surgery prior to planned second stage with the most common complication being infection (86.1%).

CONCLUSIONS

This study has summarised the large variety in static spacer constructs used for staged revision KR for PJI. Static spacers were associated with a high risk of complications and further work in this area is required to improve the quality of care in this vulnerable group.

Loop recorder implantation in patients as young as 3-months of age; the benefit of the sub-scapular approach

BACKGROUND

Loop recorder implants may have value in pediatric patients; however, size limitations exist due to the risk of erosion.

METHODS

Retrospective review of five patients who underwent subscapular loop recorder implantation were reviewed.

RESULTS

No complications occurred. Stable R-waves were noted but could be positional but with adequate diagnostics provided.

CONCLUSION

Subscapular loop recorder implantation is feasible in patients as young as 3 months of age.

Mycobacterium avium complex prosthetic joint infection: A systematic review of the literature and pooled analysis

BACKGROUND

Mycobacterium avium complex (MAC) prosthetic joint infection (PJI) has been rarely reported.

METHODS

This study aimed to investigate the epidemiology and outcomes of MAC PJI. A systematic review of the literature regarding the MAC infection following total joint arthroplasty including hip and knee joint was performed. Multiple databases were searched for published English-written articles up to May 2023. Studies that reported cases of PJI by MAC were reviewed.

RESULTS

A total of 17 patients were identified and analyzed from 11 published studies. All patients presented with joint symptom of pain or swelling prior to the diagnosis and MAC was confirmed by culture. The most of the patients (16/17 patients, 94.1%) were noted to have underlying medical condition(s) that might have affected immunity. Treatment consisted of anti-MAC medication therapy only in two patients and anti-MAC medication therapy plus surgery in 15 patients. Among the patients who underwent surgery, 14 patients (82.3%) had removal of the prosthesis including seven patients who had two-stage surgery to have reimplantation of the prosthesis. No relapse of MAC infection was reported despite of one case of relapse of infection caused by different pyogenic bacteria. The rate of overall mortality was 29.4%, however, identified attributable mortality due to MAC infection was low (5.9%).

CONCLUSION

PJI by MAC is a rare disease. However, MAC needs to be considered in the differential diagnosis in immunocompromised patients presenting with symptoms of PJI. Two-stage exchange arthroplasty may result in successful treatment outcomes without higher risks of relapse of infection if undertaken in association with appropriate active anti-MAC antibiotic therapy.

[Options and limits of leg length correction in paediatric orthopaedics]

For paediatric orthopaedic surgeons treating leg length discrepancy, knowledge of the available procedures and their options and limits is just as important as mastery of the very different surgical methods and implants, as well as the possible complications, in order to be able to advise and treat the children and adolescents and their parents comprehensively and in the best interests. Both the growth inhibiting procedures and the complex bone lengthening procedures require a great deal of experience to successfully guide patients and families through what is often a lengthy and sometimes complicated treatment process. Careful preoperative indications and planning, precise surgical techniques with suitable instruments and implants, and attentive postoperative check-ups are mandatory prerequisites for the desired therapeutic success.

Retrospective comparison of long-term functionality and revision rate of two different shunt valves in pediatric and adult patients

PURPOSE

The most frequent therapy of hydrocephalus is implantation of ventriculoperitoneal shunts for diverting cerebrospinal into the peritoneal cavity. We compared two adjustable valves, proGAV and proGAV 2.0, for complications resulting in revision surgery.

METHODS

Four hundred patients undergoing primary shunt implantation between 2014 and 2020 were analyzed for overall revision rate, 1-year revision rate, and revision-free survival observing patient age, sex, etiology of hydrocephalus, implantation site, prior diversion of cerebrospinal fluid, and cause of revision.

RESULTS

All data were available of all 400 patients (female/male 208/192). Overall, 99 patients underwent revision surgery after primary implantation. proGAV valve was implanted in 283 patients, and proGAV 2.0 valves were implanted in 117 patients. There was no significant difference between the two shunt valves concerning revision rate (p = 0.8069), 1-year revision rate (p = 0.9077), revision-free survival (p = 0.6921), and overall survival (p = 0.3232). Regarding 1-year revision rate, we observed no significant difference between the two shunt valves in pediatric patients (40.7% vs 27.6%; p = 0.2247). Revision operation had to be performed more frequently in pediatric patients (46.6% vs 24.8%; p = 0.0093) with a significant higher number of total revisions with proGAV than proGAV 2.0 (33 of 59 implanted shunts [55.9%] vs. 8 of 29 implanted shunts [27.6%]; p = 0.0110) most likely due to longer follow-up in the proGAV-group. For this reason, we clearly put emphasis on analyzing results regarding 1-year revision rate.

CONCLUSION

According to the target variables we analyzed, aside from lifetime revision rate in pediatric patients, there is no significant difference between the two shunt valves.

Experience With the New Active Transcutaneous Bone-Conduction Implant With Smaller Dimensions

OBJECTIVE

Recently, the Bonebridge 602 implant was introduced. Its smaller dimensions facilitate implantation even in surgically demanding cases. However, in extreme anatomical conditions, implant lifts are still required. We intended to report on the medical and audiological outcomes of all patients implanted with the implant with a secondary focus on the safety, efficacy, and feasibility of the use of 1-mm lifts.

STUDY DESIGN

Retrospective cohort study.

SETTING

Tertiary academic center.

METHODS

We retrospectively analyzed all patients implanted with the Bonebridge 602. Patient demographics and surgically-specific data were collected from the medical charts. Furthermore, audiological results were assessed. Outcomes were compared between implantations with versus without lifts.

RESULTS

Twenty-one devices were implanted during the study period. Satisfactory audiological results were observed, while no intra- or postoperative adverse events occurred. The majority of patients were daily users at the end of the observation period (n = 20/21, 95.2%), and one patient (n = 1/21, 4.8%) was a nonuser after 6 months of use because of subjective dissatisfaction. Due to anatomical considerations, 1-mm lifts were used in 4 implantations (19.0%). The application of lifts did not result in prolonged surgical times, complications, or shorter time of use, nor did it negatively affect audiometric results.

CONCLUSION

Implantations with the new and smaller Bonebridge were associated with gratifying medical and audiological outcomes. Still, in extreme anatomical conditions, 1-mm lifts are necessary. Nonetheless, surgical placement with the help of lifts seems safe, effective, and feasible, and is a viable option in cases with challenging anatomies due to previous surgeries or anomalies.

Incidence and risk factors of in-hospital prosthesis-related complications following total shoulder arthroplasty

BACKGROUND

The occurrence of prosthesis-related complications after total shoulder arthroplasty is devastating and costly. The purpose was to determine the incidence and risk of in-hospital prosthesis-related complications after total shoulder arthroplasty utilizing a large-scale sample database.

METHODS

A retrospective database analysis was performed based on Nationwide Inpatient Sample from 2010 to 2014. Patients who underwent total shoulder arthroplasty were included. Patient demographics, hospital characteristics, length of stay, economic indicators, in-hospital mortality, comorbidities, and peri-operative complications were evaluated.

RESULTS

A total of 34,198 cases were capture from the Nationwide Inpatient Sample database. There were 343 cases of in-hospital prosthesis-related complications after total shoulder arthroplasty and the overall incidence was 1%, with a more than 2.5-fold decrease from 2010 to 2014. Dislocation was the most common category among prosthesis-related complications (0.1%). The occurrence of in-hospital prosthesis-related complications was associated with significantly more total charges and slightly longer length of stay while less usage of Medicare. Risk factors of prosthesis-related complications were identified including younger age (<64 years), female, the native American, hospital in the South, alcohol abuse, depression, uncomplicated diabetes, diabetes with chronic complications, fluid and electrolyte disorders, metastatic cancer, neurological disorders, and renal failure. Interestingly, advanced age (≥65 years) and proprietary hospital were found as protective factors. Furthermore, prosthesis-related complications were associated with aseptic necrosis, rheumatoid arthritis, rotator cuff tear arthropathy, Parkinson's disease, prior shoulder arthroscopy, and blood transfusion.

CONCLUSIONS

It is of benefit to study risk factors of prosthesis-related complications following total shoulder arthroplasty to ensure the appropriate management and optimize consequences although a relatively low incidence was identified.

The Era of Biomaterials: Smart Implants?

Conditions, accidents, and aging processes have brought with them the need to develop implants with higher technology that allow not only the replacement of missing tissue but also the formation of tissue and the recovery of its function. The development of implants is due to advances in different areas such as molecular-biochemistry (which allows the understanding of the molecular/cellular processes during tissue repair), materials engineering, tissue regeneration (which has contributed advances in the knowledge of the properties of the materials used for their manufacture), and the so-called intelligent biomaterials (which promote tissue regeneration through inductive effects of cell signaling in response to stimuli from the microenvironment to generate adhesion, migration, and cell differentiation processes). The implants currently used are combinations of biopolymers with properties that allow the formation of scaffolds with the capacity to mimic the characteristics of the tissue to be repaired. This review describes the advances of intelligent biomaterials in implants applied in different dental and orthopedic problems; by means of these advances, it is expected to overcome limitations such as additional surgeries, rejections and infections in implants, implant duration, pain mitigation, and mainly, tissue regeneration.

Individual computer-assisted 3D planning for placement of auricular prosthesis anchors in combination with an implantable transcutaneous bone conduction hearing device in patients with aural atresia

BACKGROUND

The simultaneous implantation of the Bonebridge (MED-EL, Innsbruck, Austria), a semi-implantable active transcutaneous bone conduction hearing device and anchors for auricular prostheses can be challenging as both implants contain magnets and compete for the narrow space in the designated implantation area.

MATERIAL AND METHODS

A preoperative planning tool (virtual surgery) was used with individual 3D computer models of the skull and implants for finding optimal implant positions for both the floating mass transducer (FMT) and the anchors for the auricular prosthesis. The interaction between the magnetic prosthesis anchors and the FMT was measured by means of static magnetic forces. A retrospective data analysis was conducted to evaluate the surgical and audiological outcome.

RESULTS

Between 2014 and 2021, a 3D planning of a simultaneous implantation of the Bonebridge with auricular prosthesis anchors was conducted on 6 ears of 5 patients (3 males, 2 females; age range 17-56 years). The individual preoperative planning was considered very useful for the optimal placement of bone anchors in combination with the Bonebridge. Audiological data showed a clear benefit for hearing 3 months and > 11 months after implantation. No adverse interactions between the magnetic prosthesis anchors and the FMT were observed. In two patients, revision surgery was carried out due to skin inflammation or wound healing problems. No long-term complications were observed 3-5 years after surgery.

CONCLUSION

Preoperative 3D planning represents a clear benefit for the simultaneous audiological and esthetic rehabilitation using the Bonebridge and anchors for auricular prostheses.

Twelve-Month Clinical and Histopathological Performance of a Novel Synthetic Cornea Device in Rabbit Model

Purpose

To report the biological stability and postoperative outcomes of a second-generation, single-piece, flexible synthetic cornea in a rabbit model.

Methods

Device materials and design were amended to enhance biointegration. Optic skirt design devices were made from compact perfluoroalkoxy alkane with porous expanded polytetrafluoroethylene ingrowth surface overlying the skirt and optic wall. Sixteen devices were implanted into intrastromal pocket in rabbit eyes. Rabbits were randomly assigned to 6- and 12-month follow-up cohorts (n = 8 in each) postoperatively. Monthly examinations and optical coherence tomography assessed cornea-device integration, iridocorneal angle, optic nerve, and retina.

Results

There were no intraoperative complications. All devices were in situ at exit, with clear optics. No retroprosthetic membrane, glaucoma, cataract formation, or retinal detachment was observed. Two rabbits in the 6-month group had mild, focal anterior lamella thinning without retraction adjacent to the optic near tight sutures. Three postoperative complications occurred in the 12-month group. One rabbit diagnosed with endophthalmitis was euthanized on day 228. Mild sterile focal retraction of anterior lamella occurred in two rabbits, which were terminated on days 225 and 315. Light microscopic examination of enucleated globes demonstrated fibroplasia with new collagen deposition into the porous scaffold without significant inflammation, encapsulation, or granuloma formation.

Conclusions

Clinical evaluations, imaging, and histopathological findings indicate favorable outcomes of this synthetic corneal device in a rabbit model. Early feasibility studies in humans are being planned.

Translational Relevance

Favorable 12-month results of the device in rabbits demonstrate vision-restoring potential in corneally blind individuals at high risk of failure with donor keratoplasty.

Surgical Site Infection in Patients Managed with an Endoprosthesis for the Treatment of Cancer: Evaluation of Patient, Disease, and Index Surgical Factors

BACKGROUND

Surgical site infection (SSI) after segmental endoprosthetic reconstruction in patients treated for oncologic conditions remains both a devastating and a common complication. The goal of the present study was to identify variables associated with the success or failure of treatment of early SSI following the treatment of a primary bone tumor with use of a segmental endoprosthesis.

METHODS

The present study used the Prophylactic Antibiotic Regimens in Tumor Surgery (PARITY) data set to identify patients who had been diagnosed with an SSI after undergoing endoprosthetic reconstruction of a lower extremity primary bone tumor. The primary outcome of interest in the present study was a dichotomous variable: the success or failure of infection treatment. We defined failure as the inability to eradicate the infection, which we considered as an outcome of amputation or limb retention with chronic antibiotic suppression (>90 days or ongoing therapy at the conclusion of the study). Multivariable models were created with covariates of interest for each of the following: surgery characteristics, cancer treatment-related characteristics, and tumor characteristics. Multivariable testing included variables selected on the basis of known associations with infection or results of the univariable tests.

RESULTS

Of the 96 patients who were diagnosed with an SSI, 27 (28%) had successful eradication of the infection and 69 had treatment failure. Baseline and index procedure variables showing significant association with SSI treatment outcome were moderate/large amounts of fascial excision ≥1 cm2) (OR, 10.21 [95% CI, 2.65 to 46.21]; p = 0.001), use of local muscle/skin graft (OR,11.88 [95% CI, 1.83 to 245.83]; p = 0.031), and use of a deep Hemovac (OR, 0.24 [95% CI, 0.05 to 0.85]; p = 0.041). In the final multivariable model, excision of fascia during primary tumor resection was the only variable with a significant association with treatment outcome (OR, 10.21 [95% CI, 2.65 to 46.21]; p = 0.018).

CONCLUSIONS

The results of this secondary analysis of the PARITY trial data provide further insight into the patient-, disease-, and treatment-specific associations with SSI treatment outcomes, which may help to inform decision-making and management of SSI in patients who have undergone segmental bone reconstruction of the femur or tibia for oncologic indications.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Intra-operative optical coherence tomography in corneal lamellar graft reinforcement for Boston type I keratoprosthesis corneal melt

Corneal melt is a sight-threatening complication of Boston type 1 keratoprosthesis (KPro). Severe corneal melt may result in hypotony, choroidal hemorrhage, and even spontaneous extrusion of the KPro, which may lead to a poor visual prognosis. Lamellar keratoplasty is one surgical option for the management of mild corneal melt, especially when a new KPro is not available. Herein, we present a new surgical technique application, intra-operative optical coherence tomography (iOCT) for the management of cornea graft melt after Boston type 1 KPro implantation. The visual acuity and the intra-ocular maintained stable at 6 months post-operatively, and the KPro remained in place without corneal melting, epithelial ingrowth, or infection. iOCT may prove to be a real-time, non-invasive, and accurate treatment for corneal lamellar dissection and suturing beneath the anterior plate of the KPro, which can effectively help the surgeon to make surgical decisions and reduce post-operative complications.

Incidence and risk factors for glaucoma development and progression after corneal transplantation

OBJECTIVE

To assess the cumulative incidence and risk factors for glaucoma development and progression within 1-2 years following corneal transplant surgery.

DESIGN

Retrospective cohort study.

METHODS

Patients undergoing penetrating keratoplasty (PK), deep anterior lamellar keratoplasty (DALK), Descemet stripping endothelial keratoplasty (DSEK), Descemet membrane endothelial keratoplasty (DMEK), Boston keratoprosthesis type I (KPro) implantation, or endothelial keratoplasty (DSEK or DMEK) under previous PK (EK under previous PK) at one academic institution with at least 1 year of follow-up were included. Primary outcome measures were cumulative incidence of glaucoma development and progression after corneal transplant, in patients without and with preoperative glaucoma, respectively. Risk factors for glaucoma development and progression were also assessed.

RESULTS

Four hundred and thirty-one eyes of 431 patients undergoing PK (113), DALK (17), DSEK (71), DMEK (168), KPro (35) and EK under previous PK (27) with a mean follow-up of 22.9 months were analyzed. The 1-year cumulative incidence for glaucoma development and progression was 28.0% and 17.8% in patients without and with preoperative glaucoma, respectively. In a Cox proportional hazards analysis, DSEK surgery, KPro implantation, average intraocular pressure (IOP) through follow-up and postoperative IOP spikes of ≥30 mmHg were each independently associated with glaucoma development or progression (p < 0.04 for all).

CONCLUSIONS

A significant proportion of patients developed glaucoma or exhibited glaucoma progression within 1 year after corneal transplantation. Patient selection for DSEK may partly explain the higher risk for glaucoma in these patients. Postoperative IOP spikes should be minimized and may indicate the need for co-management with a glaucoma specialist.

Pediatric Cranioplasty Patients With Hostile Reconstructive Environments: Split Calvarial Versus Prosthetic Implant

INTRODUCTION

Pediatric cranial defects can be preceded by prior infection, radiation therapy, failed prior cranioplasty, or cerebrospinal fluid leak, leading to a complex reconstructive environment. The primary aim of this study was to investigate differences in outcomes between pediatric patients with hostile reconstructive environments who received split-calvarial autologous grafts as opposed to prosthetic grafts in cranioplasty.

METHODS

We performed an institutional review board-approved retrospective chart review of 51 patients younger than 18 years who underwent cranioplasty with a hostile setting between 1998 and 2020. Patients were then stratified into prosthetic (45%) and autologous groups (54%). The primary outcome measured was postoperative complication, defined as requirement of a subsequent surgery or revision.

RESULTS

Overall, there were no significant differences in age, sex, type of hostile setting, etiology of cranial defect, or side of the cranial defect between the 2 groups. Complication rate among the 2 graft groups was 18%. However, there were no significant differences in complications, defined as infection, failure or resorption of the graft, wound breakdown or necrosis, resulting bone defect, or hematoma, between the 2 populations. There was a significant difference in etiology between patients with complications, with patients who required a cranioplasty due to previous hemicraniectomy being nearly 5 times as likely to face a complication ( P = 0.045).

CONCLUSIONS

In our study, there was no significant difference observed in complications between prosthetic and split-thickness autologous grafts in pediatric patients with hostile settings. It does, however, seem that patients who had a previous hemicraniectomy are more likely to face complications as a result of cranioplasty.