Subchondroplasty for Osteonecrosis of the Knee.

Subchondroplasty is a relatively new minimally invasive procedure that has been used to treat bone marrow edema associated with osteoarthritis. Subchondroplasty as treatment for early stage osteonecrosis of the knee has not been extensively studied. The authors hypothesized that subchondroplasty may be an effective treatment for relieving pain, improving function, and preventing collapse in osteonecrosis. In this study, a retrospective review of 11 cases of subchondroplasty of the distal femur was conducted. There were no surgical complications with the procedure, and patients reported statistically significant improvement in pain and function. The mean Knee injury and Osteoarthritis Outcome Score for Joint Replacement improved from 44.3±4.9 preoperatively to 65.73±17.2 postoperatively. The mean visual analog scale score for knee pain was 7.8±1.18 preoperatively and 3.7±1.57 postoperatively. There has been one case of recurrence of osteonecrosis and no cases of joint collapse since the procedures occurred between 2018 and 2021. Previously, subchondroplasty for the treatment of osteonecrosis of the talus as well as of the knee joint showed positive results. This study affirms that subchondroplasty may also be a useful treatment option for relieving pain, improving function, and preventing joint collapse in osteonecrosis of the knee. [Orthopedics. 2023;46(5):e287-e290.].

Inhibition of LSD1 in MDS progenitors restores differentiation of CD141Hi conventional dendritic cells.

The use of immunotherapy to treat patients with myelodysplastic syndromes (MDS) shows promise but is limited by our incomplete understanding of the immunologic milieu. In solid tumors, CD141Hi conventional dendritic cells (CD141Hi cDCs) are necessary for antitumor immunosurveillance and the response to immunotherapy. Here, we found that CD141Hi cDCs are reduced in MDS bone marrow and based on the premise established in solid tumors, we hypothesized that reduced numbers of CD141Hi cDCs are associated with inferior overall survival in MDS patients. We found that MDS patients with reduced numbers of CD141Hi cDCs, but not other DC populations, showed reduced overall survival. To examine the basis for reduction in CD141Hi cDCs, we found fewer numbers of progenitors committed to DC differentiation in the MDS bone marrow and these progenitors expressed lower levels of interferon regulatory factor-8 (IRF8), a master regulator of CD141Hi cDC differentiation. To rescue impaired CD141Hi cDC differentiation, we used pharmacologic inhibition of lysine-specific demethylase 1A (LSD1) to promote CD141Hi cDC differentiation by MDS progenitors. These data reveal a previously unrecognized element of the MDS immunologic milieu. Epigenetic regulation of CD141Hi cDC differentiation offers an intriguing opportunity for intervention and a potential adjunct to immunotherapy for patients with MDS.

Evaluation of the Proximal Ulna Dorsal Angulation for Ulnar Component Sizing in Elbow Prosthetic Reconstruction After Distal Humeral Resection of Tumor.

INTRODUCTION: Elbow prosthetic reconstruction after distal humeral tumor resection is challenging. We identify the value of the proximal ulna dorsal angulation (PUDA) as an easily-measured radiographic parameter that can help inform ulnar component sizing in the Solar Elbow System (SES) and the Modular Universal Tumor and Revision System (MUTARS), two modular prosthetic systems that are commonly used after tumor resection in this anatomic location. We hypothesized that a larger PUDA measurement would require smaller ulnar stems. METHODS: Demographic data and PUDA measurements were retrospectively reviewed for 514 patients. Multivariate regression was used to determine the effects of patient demographic data on the PUDA. PUDA measurements were collected by three independent reviewers on lateral elbow radiographs. MUTARS and SES templating software was then used to validate the relationship between the PUDA and ulnar stem sizing. RESULTS: Regression analysis showed no substantial contribution of demographic variables to the PUDA measurement (adjusted R2 = 0.02, F(6, 508) = 2.704, P = 0.01). The MUTARS implant fit 97% of elbows with a PUDA <5° and 91.6% of elbows with PUDA ≥5° (P = 0.26). The largest SES combination fit 100% of elbows with a PUDA ≤10° versus 93% of elbows with a PUDA >10° (P = 0.029). Elbows accommodating the largest SES combination had a smaller median PUDA (5.4° versus 11.7°, P = 0.034); elbows accommodating the MUTARS implant had a smaller median PUDA (5.4° versus 5.8°, P = 0.34). DISCUSSION: The PUDA is a valuable and easily used preoperative planning tool for prosthetic elbow reconstruction after tumor resection. The proximal ulna dorsal angulation can be easily measured to predict ulnar component fit and reduce intraoperative complications. In patients with a PUDA ≥5°, ulnar component stem fit for current systems may be more challenging.

Complete Remission of Bone Metastases in Renal Cell Carcinoma with Nivolumab.

A 60-year-old female, who presented with abdominal discomfort, was noted to have an enhancing left renal mass, with central necrosis on a CT scan. She underwent radical nephrectomy and biopsy revealed clear cell renal cell carcinoma, Fuhrman grade 4. After 1.5 years of her surgery, she developed metastatic disease with pulmonary nodules and was started on sunitinib. She had disease progression with development of a new 8.2 x 7.6 cm expansile, lytic bony lesion with a complete destruction of the left scapula and 5th left rib lesion. She was treated with Nivolumab for three years. Scans revealed complete resolution of the left scapular metastasis, left rib lesion and the pulmonary nodules. The patient experienced no skeletal-related event (SRE), and no bisphosphonates or receptor activator of nuclear factor-kappa B ligand (RANKL) inhibitor was used. The patient remains in complete remission, three years out of treatment. This case highlights the importance of exploring this particular class of drugs for renal cell carcinoma (RCC) with bone metastasis.

NCCN Guidelines Insights: Bone Cancer, Version 2.2017.

The NCCN Guidelines for Bone Cancer provide interdisciplinary recommendations for treating chordoma, chondrosarcoma, giant cell tumor of bone, Ewing sarcoma, and osteosarcoma. These NCCN Guidelines Insights summarize the NCCN Bone Cancer Panel's guideline recommendations for treating Ewing sarcoma. The data underlying these treatment recommendations are also discussed.

A case of long term survival with skeletal only metastatic breast cancer.

INTRODUCTION: The prognosis of patients with metastatic breast cancer is very poor. Because of this, treatment of skeletal metastasis is often palliative with limited goals rather than cure. However, there are those patients, such as presented here, who survive for an extended time. PRESENTATION OF CASE: This thirty-six year old female presented with lytic lesions to one ulna and rib five years after mastectomy for breast cancer. Despite radiation and chemotherapy, the ulnar lesion expanded and resulted in an elbow dislocation. The rib lesion was resected and the arm amputated above the elbow. She developed local recurrence in both her above elbow amputation stump and chest wall and a more proximal below shoulder amputation was performed with resection of chest wall lesion. Even though she had locally aggressive disease, she has survived for 31 years after diagnosis without any evidence of disease. DISCUSSION: Reports of metastatic breast cancer survival indicate the five year survival to be 15%. There have been few reports indicating that those patients with skeletal only or oligometastatic disease have improved prognosis. It is not clear what biological properties of these tumors results in the improved survival. CONCLUSION: This case highlights the challenges of giving patients the optimal treatment in the light of limited ability to predict prognosis. It also highlights the need to further investigate the phenotypes of breast cancer that can, despite metastatic disease and with modern treatment go on to long survival. In addition this case demonstrates the importance of long term followup.

Hip arthroscopic portal bridge retraction technique for improved peripheral compartment visualization.

Hip arthroscopy has been shown to be an effective technique in managing an increasingly widening set of indications for hip pathology. In any arthroscopic procedure, obtaining good visualization is one of the most critical components to performing a successful operation. Whereas other authors have described various techniques for improving visualization, we describe an additional simple but effective technique in this report. We describe the use of a retracting suture bridge between portal sites that allows for improved visualization of the peripheral compartment in hip arthroscopy, as well as other arthroscopic procedures.

Pulmonary sequestration with CCAM type II appearing as adrenal tumor protruding through a Bochdalek hernia.

A case of a pulmonary sequestration, which almost exclusively consisted of a congenital cystic adenomatoid malformation type II located subdiaphragmatically in the left retroperitoneal area, is reported. This case, in a 24-year-old male patient, is unique in that it appeared as an adrenal incidentaloma and extended through a Bochdalek hernia into the pleural space. It was discovered upon routine ultrasound screening for hepatocellular carcinoma in a patient with a carrier state for hepatitis B. Diagnosis was established only upon histological analysis of the surgically removed tumor after staining with hematoxylin and eosin as well as surfactant A and B. The location of the tumor may indicate that it was formed by an entrapment of a lung bud by the developing diaphragm. This appearance may give us insight into the formation of such tumors. It also highlights the difficulty of diagnosing subdiaphragmatic retroperitoneal tumors without histological examination.