Humeral stem loosening is not always prosthetic joint infection

BACKGROUND

Aseptic humeral stem loosening is an uncommon complication of shoulder arthroplasty, and its presence has been considered a highly specific predictor of prosthetic joint infection (PJI). Literature on aseptic humeral stem loosening is sparse. The primary purpose of this study was to determine the rate of aseptic humeral loosening in revision shoulder arthroplasty. Secondarily, we sought to identify predictors of septic and aseptic humeral loosening.

METHODS

Our institutional revision shoulder arthroplasty database was reviewed. Inclusion criteria were patients with humeral stem loosening as indicated in the operative report. Patient demographics, index surgery and indication, revision surgery and indication, and operative data were recorded. Charts were manually reviewed, and PJI scores were calculated using the International Consensus Meeting scoring criteria. International Consensus Meeting classifications of PJI "unlikely" and "possible" were considered aseptic, and PJI "probable" and "definite" were considered septic. Statistical analysis was performed to determine associations between the abovementioned variables and aseptic humeral loosening.

RESULTS

Forty-six patients with 48 shoulders were included in our analysis. Ten cases (21%) were classified as definite PJI, 13 cases (27%) were classified as probable PJI, 4 cases (8%) were classified as possible PJI, and 21 cases (44%) were classified as PJI unlikely. On analysis of stem design, there were no statistically significant associations with aseptic loosening; although, a lack of proximal porous ingrowth surface trended toward higher rates of aseptic loosening in all patients and in anatomic total shoulder arthroplasty (ATSA) and reverse total shoulder arthroplasty (RTSA) subgroup analyses. In the index RTSA subgroup, aseptic loosening was associated with female sex (P = .005). Seventeen of 39 shoulders (44%) that underwent either index ATSA or RTSA demonstrated concomitant glenoid loosening. The absence of glenoid loosening was associated with aseptic humeral loosening in index ATSA and RTSA (P < .001).

CONCLUSION

Fifty-two % of revision shoulder arthroplasty cases with humeral loosening performed at our institution were aseptic. There appear to be distinct demographic and radiographic factors that are more commonly associated with aseptic as opposed to septic humeral loosening. Our data demonstrate that demographic predictors of aseptic loosening of RTSA include female sex. The absence of glenoid component loosening is associated with aseptic humeral loosening and concomitant glenoid loosening is associated with septic humeral loosening. Understanding of these factors can guide the preoperative index of suspicion for PJI in the setting of humeral stem loosening.

Proximal Femur Endoprosthesis Augmentation with Polymethylmethacrylate and Condylar Plate: A Case Series

Introduction

Aseptic and septic loosening by mechanical failure is one of the main causes of proximal femur endoprosthesis failure with different clinical consequences such as pain, inflammation, progressive loosening of muscular volume, and strength with functional limitation. We present a case series of four patients with aseptic and septic loosening of femur endoprosthesis that was treated with a novel technique that combines different methods to achieve primary stability.

Case Report

Four patients with an average age of 49.5 years (35-70 years), two women and two men, were referred to the Orthopedic Surgery Department of the San Ignacio University Hospital of Bogota. Two of them with a history of oncological disease, ruling out a tumor relapse through local images and extension examinations; another patient with a history of firearm injury to the left thigh with multiple secondary complications, which required various reconstructive procedures; and the oldest patient with a history of total hip replacement. The main complaint of the four patients was thigh pain not caused by trauma and initial assessment radiographs of all of them showed signs of loosening of the prosthetic material, with septic etiology in two of the patients and aseptic etiology in the other two. Therefore, they were scheduled for revision surgery of prosthetic components. These patients recover functional status and resolved pain in the early post-operative period and during long-term follow-up. Only one of the patients, time after the surgical procedure, required removal of the osteosynthesis material due to persistent bone infectious process.

Conclusion

Septic and aseptic loosening is one of the most common complications of proximal femur endoprosthesis, resulting in significant pain and functional decline in patients. We present a novel surgical technique that allows primary stabilization of the construct that allows early rehabilitation, improvement of functionality, and no signs of new loosening.

Total hip arthroplasty revision etiologies: a cross-sectional study in Isfahan, Iran

BACKGROUND

Complications after primary total hip arthroplasty (THA) are the most common reason for revision. Due to the high prevalence of revision surgery, we investigated the frequency of postprimary THA complications and related risk factor revision surgery.

MATERIALS AND METHODS

This is a cohort study that was performed in 2011-2019 on all patients who underwent primary THA surgery re-admitted to the Kashani and Saadi Hospital affiliated to Isfahan University of Medical Science, Iran, due to some complications after THA. Demographic and basic data were collected from patient's medical documents. Harris hip score (HHS) was calculated for all patients 6 months after the last surgery. The obtained data were analyzed using SPSS software version 21. Appropriate statistical tests were conducted to compare the results between the study groups.

RESULTS

Among 1260 patients who underwent primary THA, 1006 of them entered the study after applying the exclusion criteria. Thirty nine patients were under revision, 53.8% had prosthesis infection, 56.4% had instability, 6% had aseptic loosening, and 30.8% had periprosthetic fracture. Odds ratio for the above complications were 45.5, 45, 6.4, and 15.5, respectively. HHS postoperatively was also significantly (P < 0.001) higher in patients without revision. No correlation between gender or surgeon experience and revision was detected; however wound discharge (P < 0.001), body mass index (BMI) (P = 0.003), and Infection during hospitalization (P < 0.001) affect revision rate significantly. All four postsurgery complications, i.e., instability, postoperative prothesis infections, periprosthetic fractures, and aseptic loosening, significantly increased the risk of revision (P < 0.001, for all).

CONCLUSION

Instability, prosthetic infections, periprosthetic fractures, and aseptic loosening were the most common causes for increasing revision rates after THA, respectively. Higher BMI, persistent wound discharge, and nosocomial infections during the first hospitalization also increased the rate of revision after primary THA.

Transfibular total ankle arthroplasty : a new reliable procedure at five-year follow-up

AIMS

This study reports updates the previously published two-year clinical, functional, and radiological results of a group of patients who underwent transfibular total ankle arthroplasty (TAA), with follow-up extended to a minimum of five years.

METHODS

We prospectively evaluated 89 patients who underwent transfibular TAA for end-stage osteoarthritis. Patients' clinical and radiological examinations were collected pre- and postoperatively at six months and then annually for up to five years of follow-up. Three patients were lost at the final follow-up with a total of 86 patients at the final follow-up.

RESULTS

A total of 86 patients were evaluated at a mean follow-up of 65.4 months (60 to 90). At five-year follow-up, statistically significant improvements (p < 0.001) were found in the mean American Orthopaedic Foot & Ankle Society Ankle Hindfoot Score (from 33.8 (SD 14.3) to 86.1 (SD 8.8)), visual analogue scale for pain (from 8.5 (SD 1.7) to 1.5 (SD 1.2)), Short Form-12 Physical and Mental Component Scores (from 29.9 (SD 6.7) and 43.3 (SD 8.6) to 47.3 (SD 7.5) and 52.2 (SD 8.0), respectively), and mean ankle dorsiflexion and plantarflexion (from 6.2° (SD 5.5°) and 9.6° (SD 5.8°) to 23.9° (SD 7.7°) and 16.9° (SD 7.2°), respectively). Radiologically, the implants maintained neutral alignment without subsidence. Tibial or talar radiolucency was found in eight patients, but none of these patients was symptomatic. At five-year follow up, 97.7% of implants (95% confidence interval 91.2 to 99.4) were free from revision or removal with 84 implants at risk. We recorded two cases (2.3%) of failure for septic loosening.

CONCLUSION

Transfibular TAA is safe and effective with a high survival rate at mid-term follow-up and satisfactory clinical and radiological results. Further studies are required to determine the long-term performance of these implants. Cite this article: Bone Joint J 2022;104-B(4):472-478.

The Use of a Megaprosthesis in the Management of Stem Loosening after Revision Hip Arthroplasty in a Patient with Extensive Femoral Bone Destruction. Case Study

This paper presents the case of a female patient who underwent eleven revision surgeries after primary hip arthroplasty due to infection and loosening of the stem and acetabulum. We decided that in order to save the limb, it was necessary to use a total femur prosthesis. Three years' follow-up showed that the patient was satis-fied with the outcome of the surgery.

IRAK-4 in macrophages contributes to inflammatory osteolysis of wear particles around loosened hip implants

TLRs recognizing PAMPS play a role in local immunity and participate in implant-associated loosening. TLR-mediated signaling is primarily regulated by IL-1 receptor associated kinase-M (IRAK-M) negatively and IRAK-4 positively. Our previous studies have proved that wear particles promote endotoxin tolerance in macrophages by inducing IRAK-M. However, whether IRAK-4 is involved in inflammatory osteolysis of wear particles basically, and the specific mechanism of IRAK-4 around loosened hip implants, is still unclear. IRAK-4 was studied in the interface membranes from patients in vivo and in particle-stimulated macrophages to clarify its role. Also, IL-1β and TNF-α levels were measured after particle and LPS stimulation in macrophages with or without IRAK-4 silenced by siRNA. Our results showed that the interface membranes around aseptic and septic loosened prosthesis expressed more IRAK-4 compared with membranes from osteoarthritic patients. IRAK-4 in macrophages increased upon particle and LPS stimulation. In the former, IL-1β and TNF-α levels were lower compared with those of LPS stimulation, and IRAK-4 siRNA could suppress production of pro-inflammatory cytokines. These findings suggest that besides IRAK-M, IRAK-4 also plays an important role in the local inflammatory reaction and contributes to prosthesis loosening.

Prevention of Periprosthetic Joint Infection (PJI): A Clinical Practice Protocol in High-Risk Patients

Background: Periprosthetic joint infection (PJI) represents 25% of failed total knee arthroplasties (TKA). The European Knee Associates (EKA) formed a transatlantic panel of experts to perform a literature review examining patient-related risk factors with the objective of producing perioperative recommendations in PJI high-risk patients. Methods: Multiple databases (Pubmed/MEDLINE, EMBASE, Scopus, Cochrane Library) and recommendations on TKA PJI prevention measures from the International Consensus Meetings on PJI from the AAOS and AAHKS were reviewed. This represents a Level IV study. Results: Strong evidence was found on poor glycemic control, obesity, malnutrition, and smoking being all associated with increased rates of PJI. In the preoperative period, patient optimization is key: BMI < 35, diet optimization, Hemoglobin A1c < 7.5, Fructosamine < 292 mmol/L, smoking cessation, and MRSA nasal screening all showed strong evidence on reducing PJI risk. Intraoperatively, a weight-based antibiotic prophylaxis, accurate fluid resuscitation, betadine and chlorhexidine dual skin preparation, diluted povidone iodine solution irrigation, tranexamic acid administration, and monofilament barbed triclosan-coated sutures for soft tissues closure all represented effective prevention measures. In the postoperative period, failure to reach normalization of ESR, CRP, D-dimer, and IL-6 six weeks postoperatively suggested early PJI. Conclusion: The current recommendations from this group of experts, based on published evidence, support risk stratification to identify high-risk patients requiring implementation of perioperative measures to reduce postoperative PJI.

Alteration of the RANKL/RANK/OPG System in Periprosthetic Osteolysis with Septic Loosening

The pathogenesis of periprosthetic osteolysis with septic loosening remains incompletely understood. The purpose of this study was to investigate whether expression of the RANKL/RANK/OPG system is altered in septic interface membranes (SIMs). Seventeen cases with a SIM, 26 cases with an aseptic interface membrane (AIM), and 12 cases with a normal synovium (NS) were assessed. Scanning and transmission electron microscopy (SEM and TEM, respectively) were used to observe the microscopic morphology of three tissue conditions. Differences in RANKL, RANK, and OPG expression at the mRNA level were assessed by real-time quantitative PCR, and differences at the protein level were assessed by immunohistochemical staining and Western blotting. SEM showed wear debris widely distributed on the AIM surface, and TEM showed Bacillus activity in the SIM. RANKL expression and the RANKL/OPG ratio were significantly increased in SIMs. Imbalance in the RANKL/RANK/OPG system is related to periprosthetic osteolysis with septic loosening but is not the only possible pathogenic mechanism.