Utility of histopathological examination in aseptic revision total hip arthroplasty: a preliminary analysis.

INTRODUCTION: The utility of a routine histopathological examination in aseptic revision total hip arthroplasty (THA) has not been well explored. We aim to describe the approach and present the results of histopathological examination, focusing on its clinical usefulness in the setting of aseptic revision THA. METHOD: We retrospectively reviewed 285 performed aseptic revision THA with available histopathological reports between 2015 and 2017 at a single institution. We described histopathological requests by the surgical team. Preoperative diagnoses, intraoperative findings, as well as histopathology and culture results were analysed. RESULTS: 13 painful THAs (4.5%) had preoperatively unknown diagnoses. In 10 of them, potential causes of pain were intraoperatively identified. Histopathology confirmed these findings in 8 THAs. 19 THAs (6.7%) revealed unexpected positive cultures (UPC). Histopathology was negative for infection in 18 of them. Among 16 consultants, 3 surgeons requested histopathology in 47% of the cases (130/285), usually to exclude infection (101/285; 35%). Documentation for tissue sample location was lacking in 51% (145/285), and for question asked by the surgeon in 47% (135/285). CONCLUSIONS: Histopathology is deemed a useful confirmatory tool in the context of ruling out infection in UPCs, and in documenting intraoperative findings in painful THAs with unknown preoperative diagnoses. Importantly, the approach to requesting histopathology should be optimised. Further large-scale studies, including cost analyses, are warranted to explore the usefulness of histopathology in routine utility.

Tibial plateau fracture: does fracture classification influence the choice of surgical approach? A retrospective multicenter analysis.

PURPOSE: The role of classification systems for the choice of surgical approach and the management of tibial plateau fractures remains unclear. The purpose of this study was to investigate the potential of classification systems to choose the appropriate operative approach. Current surgical management strategies were investigated in a large multicenter assessment. METHODS: In this study, we retrospectively analyzed all patients with tibial plateau fractures that have received surgical treatment in one of the five Level I trauma facilities between 2012 and 2015. Fractures were classified in each center by a senior orthopedic surgeon using the AO/OTA and the Luo classification. Demographics, trauma mechanism, as well as the surgical approach were recorded. RESULTS: 538 patients (46.1% male, 53.9% female) were included. The anterolateral approach was used most frequently with 54.8% of all single approaches; 76.2% of all combined approaches used anterolateral as part of the approach. Combined approaches were used in 22.5% of the cases; a combination of the anterolateral and medial (10%), anterolateral, and posteromedial approach (5.8%) were used most frequently. The lowest number was found for the posterolateral (1.3%) and the combined approaches dorsal/anterolateral and medial/dorsal (1.7%, 1.1%). The AO/OTA classification showed a peak for 41.B2 (21.9%) and B3 (35.5%) fractures. Regarding the Luo classification, the dorsal column was involved in 45.7%. In contrast, only 14.7% of the surgical approaches used were able to address the dorsal tibial plateau potentially. CONCLUSION: The use of dorsal approach seems to be of minor importance than expected in daily clinical practice in this multicenter study. It was not possible to specify whether the AO/OTA or the Luo classification can reliably predict the choice of surgical approach. The operative treatment strategy of tibial plateau fractures seems to rather rely on the surgeons' experience, education, and preferences.

What Is the Impact of Automated Synovial Cell Counting on Different Aseptic Causes and Periprosthetic Conditions Associated With Revision THA?

BACKGROUND: Studies have suggested that automated synovial cell counting may overestimate the white blood cell (WBC) count, resulting in false positive tests when evaluating patients for the possibility of periprosthetic joint infection (PJI) after THA. However, associations between WBC counts high enough to mimic PJI in patients whose arthroplasties are not infected but rather are experiencing a variety of aseptic problems-including but not limited to metallosis, polyethylene wear, and recurrent dislocation-have not, to our knowledge, been adequately addressed. In addition, there is a lack of analyses about the polymorphonuclear percentage (PMN%) when assessed by automated analyzers in this context. QUESTIONS/PURPOSES: In the context of different indications for aseptic revision and different periprosthetic hip pathologic findings, we asked: (1) What were the synovial WBC count levels, and what proportion of values were above the 2018 International Consensus Meeting (ICM) cutoff (3000 cells/µL)? (2) What were the synovial PMN% levels, and what proportion of values were above the 2018 ICM (70%)? METHODS: We retrospectively studied the preoperative cell count analyses of synovial fluid in patients who underwent revision THA for aseptic reasons at our tertiary referral arthroplasty center between January 2015 and December 2017. We considered all revisions performed on patients during that time potentially eligible, and after prespecified exclusions were applied (exclusions mainly included 15% [197 of 1306] sporadic missing data and 12% [155 of 1306] insufficient synovial fluid obtained in the aspirate), a total of 702 patients undergoing revision THA for aseptic reasons remained for the final analysis. As far as we know, no patients underwent re-revision for PJI at a mean follow-up of 46 ± 11 months, which tends to confirm our impression that indeed these hips did not have PJI. Cell count analyses were conducted using an automated analyzer. Clinical findings, preoperative radiographs, and surgical reports--confirmed by available histologic results--were used to establish diagnoses. We evaluated these hips considering the recommendations of the 2018 ICM (WBC count of 3000 cells/µL and PMN% of 70%) to see what proportion of them would have been characterized as likely having PJI on basis of those cutoff values. The mean WBC count for the entire cohort was 2120 ± 2395 cells/µL. The mean PMN% for the entire cohort was 36% ± 22%. RESULTS: Compared with aseptic loosening and recurrent dislocation, polyethylene wear had the highest mean WBC count (3817 ± 3711 cells/µL; p < 0.001). Of the investigated periprosthetic conditions, wear-induced synovitis had the highest value (4464 ± 3620 cells/µL; p < 0.001). Considering the ICM threshold, polyethylene wear showed the highest proportion of WBC counts above 3000 cells/µL among the indications for aseptic revision (60% [25 of 42]; p < 0.001). Of the periprosthetic conditions, wear-induced synovitis showed the highest proportion beyond the ICM cutoff (60% [50 of 83]; p < 0.001). The mean PMN% for aseptic causes ranged between 28% and 44% without differences among them (p = 0.12). Patients with metallosis had the highest mean PMN% of the periprosthetic conditions investigated (45% ± 25%; p = 0.007). Regarding the ICM threshold, metallosis resulted in the largest proportion of patients with a PMN% above 70% (21% [10 of 47]; p = 0.003), and that for wear-induced synovitis was 6% (5 of 83; p = 0.42) and for osteolysis was 3% (1 of 33; p = 0.51). There were no differences among aseptic loosening, recurrent dislocation, and polyethylene wear in terms of the proportion above 70% among the aseptic revision causes. CONCLUSION: Using automated cell counting, we found that WBC counts differ widely across indications for aseptic revision THA, and a high proportion of patients who underwent revision THA for aseptic reasons had WBC counts above the commonly used threshold of 3000 cells/µL. However, the PMN% was much less affected in several common indications for aseptic revision THA, making this measure more reliable for interpreting aspiration results using an automated analyzer. Based on the data distributions we observed, manual counting techniques might be considered in particular among patients with polyethylene wear, metal-on-metal bearing surfaces, or suspected metallosis. However, an elevated WBC count alone, observed using an automated analyzer in the context of polyethylene wear, should not be considered to be strongly suggestive of PJI, since that finding occurred so commonly among patients without infection. LEVEL OF EVIDENCE: Level III, diagnostic study.

High Rate of Reinfection With New Bacteria Following One-Stage Exchange for Enterococcal Periprosthetic Infection of the Knee: A Single-Center Study.

BACKGROUND: A wide range of success rates following the surgical management of enterococcal periprosthetic joint infection (PJI) with a tendency toward worse outcomes have been reported. However, the role of 1-stage exchange remains under-investigated. Therefore, we aimed to evaluate our results after the 1-stage knee exchange for enterococcal PJI. METHODS: Forty patients were retrospectively included between 2002 and 2017 with a mean follow-up of survivors of 80 months (range 22-172; standard deviation [SD] = 5). Polymicrobial infections occurred in 45% (18/40) of patients. Patients' characteristics, joint-related data, and antibiotic therapy were recorded. Rates of enterococcal infection relapse, reinfection with new microorganisms, and re-revision for any reason were determined. Bivariate analysis was conducted to identify risk factors of infection recurrence. RESULTS: Revision surgery was required in 22 cases (55%) with a mean time to revision surgery of 27 months (range 1-78; SD = 25). Indications for aseptic revisions (18%) included aseptic loosening (10%), periprosthetic fracture (5%), and patellar instability (3%). The most common cause of re-revision was a subsequent PJI (15/22; 68%) after a mean time of 22 months (range 1-77; SD = 24). Overall infection recurrence rate was 37.5% (15/40), substantially due to entirely non-enterococcal infections (9/15; 60%). Infection relapse with Enterococci occurred in 4 cases (10%) within 16 months postoperatively. Older patients (P = .05) and male gender (P = .05) were associated with a higher risk of infection recurrence. CONCLUSION: Overcoming the Enterococci using the 1-stage exchange for knee PJI is achievable but the rate of reinfection due to new microorganisms is high . However, the overall infection recurrence rate is comparable to other treatment approaches.

Revision Arthroplasty with Total Femur Replacement for the Management of Complex Post-traumatic Bone Defect in a Patient with Dwarfism. / Revisionsendoprothetik mit Totalfemurendoprothese zur Behandlung komplexer posttraumatischer Knochendefekte bei einem Patienten mit Zwergwuchs.

Dwarfism leads to an early onset of osteoarthritis of the joints of the lower limb. Due to bone deformities, arthroplasty is challenging. The incidence of implant-associated complications is higher compared to the normal population and often ends up with multiple revision arthroplasties. We report the first case in the literature of a 48-year-old patient with dwarfism who required implantation of a custom-made total femoral replacement due to aseptic stem loosening and a concomitant valgus gonarthrosis.

An alternative treatment option for Paprosky Type IIIb acetabular defect using multiple tantalum wedges - A case report.

The treatment of severe acetabular defects in revision total hip arthroplasty (Paprosky type IIIa and IIIb) is demanding and choosing the appropriate surgical technique remains controversial. The introduction of trabecular metal augments has led to a variety of new treatment options. The authors present a case of a Paprosky Type IIIb acetabular defect due to eight subsequent revisions of the left hip. The patient was treated with an alternative treatment option using multiple tantalum wedges. Anatomical reconstruction was achieved and at 12 months follow-up, the patient was pain free and was able to walk without walking aids.

The Anterior Intrapelvic Approach for Acetabular Fractures Using Approach-Specific Instruments and an Anatomical-Preshaped 3-Dimensional Suprapectineal Plate.

OBJECTIVES: Anatomical acetabular plates the anterior intrapelvic approach (AIP) were recently introduced to fix acetabular fractures through the intrapelvic approach. Therefore, we asked the following: (1) Does the preshaped 3-dimensional suprapectineal plate interfere with or even impair the fracture reduction quality? (2) How often does the AIP approach need to be extended by the first (lateral) window of the ilioinguinal approach? DESIGN: Observational case series. SETTING: Two Level 1 trauma centers. PATIENTS/PARTICIPANTS: Patients with unstable acetabular fractures in 2014. INTERVENTION: Fracture fixation with anatomical-preshaped, 3-dimensional suprapectineal plates through the AIP approach ± the first window of the ilioinguinal approach. OUTCOME MEASUREMENTS: Fracture reduction results were measured in computed tomography scans and graded according to the Matta quality of reduction. Intraoperative parameters and perioperative complications were recorded. Radiological results (according to Matta) and functional outcome (modified Merle d'Aubigné score) were evaluated at 1-year follow-up. RESULTS: Thirty patients (9 women + 21 men; mean age ± SE: 64 ± 8 years) were included. The intrapelvic approach was solely used in 19 cases, and in 11 cases, an additional extension with the first window of the ilioinguinal approach (preferential for 2-column fractures) was performed. The mean operating time was 202 ± 59 minutes; the fluoroscopic time was 66 ± 48 seconds. Fracture gaps and steps in preoperative versus postoperative computed tomography scans were 12.4 ± 9.8 versus 2.0 ± 1.5 and 6.0 ± 5.5 versus 1.3 ± 1.7 mm, respectively. At 13.4 ± 2.9 months follow-up, the Matta grading was excellent in 50%, good in 25%, fair in 11%, and poor in 14% of cases. The modified Merle d'Aubigné score was excellent in 17%, good in 37%, fair in 33%, and poor in 13% of cases. CONCLUSION: The AIP approach using approach-specific instruments and an anatomical-preshaped, 3-dimensional suprapectineal plate became the standard procedure in our departments. Radiological and functional early results justify joint preserving surgery in most cases. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Monitoring of Short-Term Erythropoietin Therapy in Rats with Acute Spinal Cord Injury Using Manganese-Enhanced Magnetic Resonance Imaging.

BACKGROUND AND PURPOSE: To evaluate the short-term outcome of erythropoietin (EPO) therapy in rats with spinal cord injury (SCI) using manganese-enhanced magnetic resonance imaging (MEMRI). METHODS: Rats were divided in an EPO and a control group. Laminectomy at Th11 was performed, followed by SCI. MnCl2 was applied into the cisterna magna and functional recovery was examined after injury using BBB-scoring. Then, rats were euthanized and the spinal cord was extracted for MEMRI. Finally, histological analysis was performed and correlated with MEMRI. RESULTS: EPO-treated animals showed significantly better functional recovery (P = .008, r = .62) and higher mean signal-to-noise ratio (SNR) in MEMRI compared to controls for slices 10-13 (P = .017, R(2) = .31) at the level of the lesion epicenter. Functional recovery correlated significantly with higher SNR values, determined using the mean SNR between slices 10 and 13 (P = .047, R(2) = .36). In this region, histology revealed a significantly decreased number of microglia cells and apoptosis in EPO-treated animals. CONCLUSION: MEMRI successfully depicts the therapeutic effect of EPO in early SCI that leads to a significant recovery in rats, a significantly reduced immune response and significantly reduced number of apoptotic cells at the height of the lesion epicenter.

Influence of a modified Nd:YAG laser treatment outside the visual axis on the morphology of Elschnig pearls.

PURPOSE: To observe changes in posterior capsule opacification (PCO) after Nd:YAG treatment with and without opening the posterior lens capsule. METHOD: This prospective randomized study included patients with regeneratory PCO. In substudy 1, a small low-energy Nd:YAG capsulotomy was performed (MiniYAG). In substudy 2, a low-energy Nd:YAG laser treatment without opening the lens capsule was performed (GentleYAG). Concerning analysis, in both substudies, the posterior capsule was divided into 4 quadrants and the quadrant where the Nd:YAG laser treatment was performed was randomly allocated. Change in PCO was analyzed using retroillumination images objectively (AQUA score: 0-10). RESULTS: In total, 27 eyes of 25 patients were used for this study. In substudy 1, the mean amount of PCO (AQUA score) for the entire posterior capsule decreased significantly (p < 0.05, ANOVA) from 5.2 (SD: 1.6) before to 4.0 (SD: 1.9) immediately after the MiniYAG. In substudy 2, the mean amount of PCO (AQUA score) for the entire posterior capsule analyzed before and immediately after the GentleYAG was 5.1 (SD: 2.4) and 5.2 (SD: 2.3), respectively. CONCLUSION: Performing a MiniYAG led to a significant PCO reduction. Gentle polishing of the posterior capsule resulted in a relevant reduction of PCO in one third of the patients.