Knee Arthroscopy Following Total Knee Arthroplasty is Not Associated With an Elevated Risk of Infection.

BACKGROUND: Recent literature has suggested that knee arthroscopy (KA) following ipsilateral primary total knee arthroplasty (TKA) may be associated with an increased risk of periprosthetic joint infection (PJI). However, prior studies on this subject have relied on insurance databases or have lacked control groups for comparison. This study aimed to evaluate the risk of PJI in patients undergoing ipsilateral KA after primary TKA at a single institution. METHODS: Our total joint registry was queried to identify 167 patients (178 knees) who underwent ipsilateral KA for any indication other than infection following primary TKA (KA + TKA group). The average time from TKA to KA was 2.1 ± 2.3 years. The average follow-up from primary TKA and from KA was 8.4 ± 5.4 years and 6.3 ± 5.4 years, respectively. The mean patient age was 63 ± 11 years, the mean body mass index was 31 ± 5, and 64% were women. The most common indications for KA were patellar clunk or patellofemoral synovial hyperplasia (66%) and arthrofibrosis (16%). Patients in the KA + TKA group were matched to 523 patients who underwent TKA without subsequent KA (TKA group) based on age, sex, date of surgery, and body mass index. The primary outcome measure was survivorship free from PJI. RESULTS: There was no statistical difference in the overall rate of PJI between the KA + TKA group (n = 2, 1.1%) compared to the TKA group (n = 3, 0.6%) (hazard ratio 2.0, 95% confidence interval 0.3 to 12.0, P = .4). At 5 and 10 years after TKA, there was no difference in survivorship free of PJI between the 2 groups (P = .8 and P = .3, respectively). CONCLUSIONS: A PJI is a rare complication of KA after TKA. The rate of PJI in patients undergoing KA following TKA is not significantly increased. LEVEL OF EVIDENCE: III.

Sacral insufficiency fractures are a frequent and painful consequence of pubic symphysis osteomyelitis.

BACKGROUND: Pubic symphysis osteomyelitis can result from urosymphyseal fistula formation. High rates of sacropelvic insufficiency fractures have been reported in this population. The aim of this study was to describe the presentation and risk factors for sacral insufficiency fractures (SIF) associated with surgical treatment of pubic symphysis osteomyelitis. METHODS: A retrospective review was performed for 54 patients who underwent surgery for pubic symphysis osteomyelitis associated with a urosymphyseal fistula at a single institution from 2009 to 2022. Average age was 71 years and 53 patients (98%) were male. All patients underwent debridement or partial resection of the pubic symphysis at the time of fistula treatment. Average width of the symphyseal defect was 65 mm (range 9-122) after treatment. RESULTS: Twenty patients (37%) developed SIF at a mean time of 4 months from osteomyelitis diagnosis. Rate of sacral fracture on Kaplan-Meier analysis was 31% at 6 months, 39% at 12 months, and 41% at 2 years. Eleven patients developed SIF prior to pubic debridement and 12 patients developed new or worsening of pre-existing SIF following surgery. Width of pubic resection was higher in patients who developed SIF (76 mm vs. 62 mm), but this did not meet statistical significance (p = 0.18). CONCLUSION: Sacral insufficiency fracture is a common sequela of pubic symphysis osteomyelitis. These fractures are often multifocal within the pelvis and can occur even prior to pubic resection. Pubectomy further predisposes these patients to fracture. Clinicians should maintain a high index of suspicion for these injuries in patients with symphyseal osteomyelitis.

Multidisciplinary Treatment of Merkel Cell Carcinoma of the Extremities: Outcomes and Factors Associated with Poor Survival in Nodal Disease.

Merkel cell carcinoma (MCC) has a tendency for lymphatic spread and locoregional recurrence, although there is little data examining the risk factors for patients with lymph node-positive extremity lesions. The purpose of the current study was to examine the outcomes and risk factors associated with nodal metastasis in extremity MCC. We retrospectively reviewed the medical record of 120 patients with extremity MCC evaluated at our institution between 1994 and 2021. The mean age of this cohort was 71 years; 33% of patients were female; and 98% were Caucasian. Seventy-eight (65%) patients presented with localized disease. Thirty-seven (31%) patients had stage III disease, and five (4%) patients had stage IV disease. Treatment of primary lesions consisted primarily of margin-negative excision and adjuvant radiotherapy. Nodal metastases were most treated with adjuvant radiation or completion lymph node dissection. Five-year disease-specific survival in our series was 88% for patients with localized disease, 89% for stage IIIa disease, 40% for stage IIIb disease and 42% for stage IV. Factors associated with worse survival included immunosuppression and macroscopic nodal disease. In conclusion, extremity MCC has a low rate of local recurrence when treated with margin-negative excision and adjuvant radiation. However, treatment of nodal metastases remains a challenge with high rates of recurrence and mortality, particularly for patients who are immunosuppressed or who have macroscopic nodal disease.

Is Bone Marrow Aspiration and Biopsy of Clinical Importance in the Initial Staging of Extraskeletal Ewing Sarcoma?

BACKGROUND: Extraskeletal Ewing sarcoma are rare tumors within the Ewing sarcoma family. Initial staging studies for extraskeletal Ewing sarcoma historically have included imaging and bone marrow aspiration and biopsy (BMAB). However, recent studies on Ewing sarcoma of bone have questioned the utility of BMAB in the initial staging of patients, but no studies of which we are aware have evaluated the role of BMAB in extraskeletal Ewing sarcoma. We suspected that BMAB was of low diagnostic yield in patients with extraskeletal Ewing sarcoma and exposed patients to potential morbidity without an impact on their clinical course. QUESTION/PURPOSE: Is BMAB a useful test in the staging of extraskeletal Ewing sarcoma? METHODS: Between January 1996 and December 2021, our institution evaluated 109 patients with a listed diagnosis of extraskeletal Ewing sarcoma. Those patients were retrospectively reviewed for this study. Of those, we considered patients with biopsy-confirmed diagnosis of extraskeletal Ewing sarcoma. Biopsy was performed based on institutional protocols, with all diagnoses assigned by a board-certified pathologist. Based on that criteria, 96% (105 of 109) were eligible. An additional 18% (20 of 109) were excluded because records of their initial diagnostic and staging workup were not available. This left 78% (85 of 109) for analysis. Of those, 52% (44 of 85) were male. The average age was 32 ± 16 years. Primary tumor locations included extremities in 26% (22 of 85), paraspinal in 20% (17 of 85), chest in 19% (16 of 85), retroperitoneum in 13% (11 of 85), intraabdominal in 12% (10 of 85), intrapelvic in 7% (6 of 85), and head or neck in 4% (3 of 85). Initial diagnostic and staging information, including the use of PET-CT, bone scan, CT chest, and BMAB, was collected. Metastatic disease at the time of presentation or during follow-up was noted. The utility of BMAB was determined by the rate of positive tests in those undergoing BMAB during the initial staging process. Descriptive statistical analysis was sufficient to address the study question, and therefore no comparative statistics were performed. RESULTS: BMAB was obtained during the initial staging process in 64% (54 of 85) of patients. This BMAB was negative in all 54 patients, including those with known metastatic disease. CONCLUSION: Diagnosing metastatic disease in extraskeletal Ewing sarcoma is important as the presence of metastases at diagnosis adversely affects prognosis. The routine use of BMAB in the staging process of extraskeletal Ewing sarcoma is of low diagnostic yield. BMAB is unlikely to diagnose metastatic involvement even in patients with known metastases to bone. We do not have enough data to suggest whether other modalities, such as PET-CT, might be more useful. Similar studies should be pursued to determine the utility of the remainder of staging modalities in patients with extraskeletal Ewing sarcoma to elucidate the most efficient and effective staging protocol. LEVEL OF EVIDENCE: Level III, diagnostic study.

Does Shorter Time to Treatment of Pediatric Supracondylar Humerus Fractures Impact Clinical Outcomes?

BACKGROUND: Treatment of supracondylar humerus (SCH) fractures within 18 hours of presentation is a tracked quality metric for ranking of pediatric hospitals. This is in contrast with literature that shows time to treatment does not impact outcomes in SCH fractures. We aim to determine whether an 18-hour cutoff for pediatric supracondylar humerus fracture treatment is clinically significant by comparing the complication risks ofpatients on either side of this timepoint. Our hypothesis is that there will be no statistically significant differences based on time to treatment. METHODS: A retrospective review of clinical outcomes was performed for 472 pediatric patients who underwent surgical management of isolated supracondylar humerus fractures between 1997 and 2022 at a single level I pediatric trauma hospital. The cohort was split based on time to surgery (within or ≥18 h from Emergency Department admission). RESULTS: Surgical treatment occurred within 18 hours of arrival in 435 (92.2%) patients and after 18 hours in 37 (7.8%) patients. Mean age was 5.6±2.2 years and 51.5% of patients were female. Gartland fracture classification was type II [n=152 (32.3%)], type III [n=284 (60.3%)], type IV [n=13 (2.8%)], or flexion-type [n=18 (3.8%)]. There were no differences in demographic characteristics or fracture classification between cohorts. Fractures in the ≥18-hour cohort were treated more commonly with 2 pins (62.2% vs. 38.5%, P =0.04). There were no statistically significant differences in open versus closed reduction, utilization of medial pins, or postoperative immobilization between cohorts. We were unable to detect any differences in postoperative complications, including non-union, delayed union, stiffness, malunion, loss of reduction, iatrogenic nerve injury, or infection. This remained true when type II fractures were excluded. CONCLUSIONS: Using an arbitrary time cutoff of <18 hours does not influence clinical outcomes in the surgical treatment of SCH fractures. This held true when type II fractures were excluded. For this reason, we recommend modification to the USNWR guidelines to decrease emphasis on time-to-treatment of SCH fractures. LEVEL OF EVIDENCE: Level III.