Improved functional status in patients undergoing cement and rebar reconstruction with total hip arthroplasty for uncontained metastatic tumors of the acetabulum.

BACKGROUND AND OBJECTIVE: Metastatic cancer of the acetabulum can produce marked pain and disability for patients. Several reconstruction techniques for such lesions have been described, with variable outcomes. The purpose of this study was to determine functional outcomes and complication rate for patients undergoing cement rebar reconstruction using posterior column screws with total hip arthroplasty for large, uncontained lesions of the acetabulum. METHODS: Twenty-two consecutive patients who underwent cement rebar reconstruction with posterior column screws and total hip arthroplasty for metastatic tumors of the acetabulum between 2014 and 2017 were identified. All cases were reviewed for patient demographics, surgical parameters, implant survival, complications, and functional status following these procedures. RESULTS: There was a significant increase in the proportion of patients able to ambulate post-surgery (95.5%) compared with presurgery (22.7%) (p < 0.001). Mean musculoskeletal tumor society score postoperatively was 17.9 (60%). Average operative time was 174 min and average estimated blood loss was 689 mL. Seven patients required an intraoperative or postoperative blood transfusion. Three patients had postoperative complications (14%), two of whom required revision (9%). CONCLUSION: Reconstruction using cement rebar with posterior column screws and total hip arthroplasty is a safe, reproducible approach that may greatly improve functional outcomes with a low rate of intraoperative or postoperative complications.

Survival and failure modes of the Compress® spindle and expandable distal femur endoprosthesis among pediatric patients: A multi-institutional study.

BACKGROUND: Expandable endoprostheses can be used to equalize limb length for pediatric patients requiring reconstruction following large bony oncologic resections. Outcomes of the Compress® Compliant Pre-Stress (CPS) spindle paired with an Orthopedic Salvage System expandable distal femur endoprosthesis have not been reported. METHODS: We conducted a multi-institutional retrospective study of pediatric patients with distal femoral bone sarcomas reconstructed with the above endoprostheses. Statistical analysis utilized Kaplan-Meier survival technique and competing risk analysis. RESULTS: Thirty-six patients were included from five institutions. Spindle survivorship was 86.3% (95% confidence interval [CI], 67.7-93.5) at 10 years. Two patients had a failure of osseointegration (5.7%), both within 12 months. Twenty-two (59%) patients had 70 lengthening procedures, with mean expansions of 3.2 cm (range: 1-9) over 3.4 surgeries. The expandable mechanism failed in eight patients with a cumulative incidence of 16.1% (95% CI, 5.6-31.5) at 5 years. Twenty-nine patients sustained International Society of Limb Salvage failures requiring 63 unplanned surgeries. Periprosthetic joint infection occurred in six patients (16.7%). Limb preservation rate was 91% at 10 years. CONCLUSIONS: There is a high rate of osseointegration of the Compress® spindle among pediatric patients when coupled with an expandable implant. However, there is a high rate of expansion mechanism failure and prosthetic joint infections requiring revision surgery. LEVEL OF EVIDENCE: Level IV, therapeutic study.

A Multicenter Virtual Multidisciplinary Sarcoma Case Conference Improves Outcome for a Rare Soft Tissue Sarcoma (Dermatofibrosarcoma Protuberans).

INTRODUCTION: The purpose of this study is to analyze the impact of a virtual multidisciplinary sarcoma case conference (VMSCC) on the outcomes of dermatofibrosarcoma protuberans (DFSP). METHODS: We compared margin status after surgery and disease-free survival (DFS) on two cohorts of patients with DFSP, one diagnosed from 2010 to 2015 and one from 2016 to 2020 (before and after virtual multidisciplinary sarcoma case conference (VMSCC) within Kaiser Permanente Northern California (KPNC), using Kaplan-Meier curves and Cox proportional hazard regression models. RESULTS: There was no significant difference between the two cohorts on demographics, tumor location, type of surgery, receipt of radiation, receipt of imatinib, or size of tumor. However, the percent of patients with positive margin after final surgery and the percent of local recurrence were significantly different: 6.5% and 6.3% for the 2010-2015 cohort, and .8% and 0% for the 2016-2020 cohort, respectively. CONCLUSION: Our data suggest that the outcomes of DFSP improved significantly after the implementation of VMSCC.

How Often Does Spindle Failure Occur in Compressive Osseointegration Endoprostheses for Oncologic Reconstruction?

BACKGROUND: Compressive osseointegration is a promising modality for limb salvage in distal femoral oncologic tumors. However, few studies have explored short-term survival rates in a large patient cohort of distal femur compressive endoprostheses or highlighted the risk factors for spindle failures. QUESTIONS/PURPOSES: We asked: (1) What is the frequency of compressive osseointegration spindle failure in distal femoral reconstructions? (2) What are the characteristics of rotational failure cases with distal femur compressive osseointegration endoprostheses? (3) What are the risk factors for mechanical and rotational failure of distal femur compressive osseointegration implantation? (4) What are other modalities of failure or causes of revision surgery, which affect patients undergoing distal femur compressive osseointegration implantation for oncologic reconstruction? METHODS: Between 1996 and 2013, 127 distal femoral reconstructions with the Compress(®) prosthesis were performed in 121 patients. During that time, 116 Compress(®) prostheses were implanted for aggressive primary tumors of the distal femur and/or failure of previous oncologic reconstruction. This approach represented approximately 91% of the distal femoral reconstructions performed during that time. Of the patients with prostheses implanted, four patients (four of 116, 3%) had died, and 37 (37 of 116, 32%) were lost to followup before 24 months. The median followup was 84 months (range, 24-198 months), and 71 patients (66% of all patients) were seen within the last 3 years. A retrospective chart review was performed to determine failure modality as defined by radiographs, clinical history, and intraoperative findings. Risk factors including age, sex, BMI, resection length, and perioperative chemotherapy were analyzed to determine effect on spindle and rotational failure rates. Survival analysis was determined using the Kaplan-Meier estimator. Differences in survival between groups were analyzed using the log rank test. Risk factors were determined using Cox proportional hazard modeling. RESULTS: Spindle survival at 5 and 10 years was 91% (95% CI, 82%-95%). Survival rates from rotational failure at 5 and 10 years were 92% (95% CI, 83%-96%); the majority of failures occurred within the first 2 years postoperatively and were the result of a twisting mechanism of injury. With the numbers available, none of the potential risk factors examined were associated with mechanical failure. The 5-year and 10-year all-cause revision-free survival rates were 57% (95% CI, 44%-67%) and 50% (95% CI, 36%-61%), respectively. CONCLUSIONS: Distal femur compressive osseointegration is a viable method for endoprosthetic reconstruction. Rotational failure is rare with the majority occurring early. No variables were found to correlate with increased risk of mechanical failure. More research is needed to evaluate methods of preventing mechanical and rotational failures in addition to other common causes of revision such as infection in these massive endoprosthetic reconstructions. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Molecular markers of early Parkinson's disease based on gene expression in blood.

Parkinson's disease (PD) progresses relentlessly and affects five million people worldwide. Laboratory tests for PD are critically needed for developing treatments designed to slow or prevent progression of the disease. We performed a transcriptome-wide scan in 105 individuals to interrogate the molecular processes perturbed in cellular blood of patients with early-stage PD. The molecular multigene marker here identified is associated with risk of PD in 66 samples of the training set comprising healthy and disease controls [third tertile cross-validated odds ratio of 5.7 (P for trend 0.005)]. It is further validated in 39 independent test samples [third tertile odds ratio of 5.1 (P for trend 0.04)]. Insights into disease-linked processes detectable in peripheral blood are offered by 22 unique genes differentially expressed in patients with PD versus healthy individuals. These include the co-chaperone ST13, which stabilizes heat-shock protein 70, a modifier of alpha-synuclein misfolding and toxicity. ST13 messenger RNA copies are lower in patients with PD (mean +/- SE 0.59 +/- 0.05) than in controls (0.96 +/- 0.09) (P = 0.002) in two independent populations. Thus, gene expression signals measured in blood can facilitate the development of biomarkers for PD.