Low Rate of Early Periprosthetic Fractures in Direct Anterior Total Hip Arthroplasty with a Triple-Tapered Wedge Stem.

INTRODUCTION: Utilization of the direct anterior approach (DAA) for total hip arthroplasty (THA) has been steadily increasing in recent years. While the DAA may offer some benefits compared to other approaches, there are still risks involved including relatively higher rates of periprosthetic femur fractures, especially when combined with cementless femoral stem use. The purpose of this study is to evaluate the early postoperative femoral complications with a short triple-wedge tapered stem used in primary THA via a DAA. MATERIALS AND METHODS: A retrospective review was conducted of the arthroplasty registry of our institution from April 2022 to August 2023 to identify patients who underwent a primary THA via a DAA with the Short Medacta Stem (SMS) (Medacta International, Castel San Pietro, Switzerland). Patients were excluded if the stem was used for a revision surgery, they were within 90 days of surgery, or they refused research consent. Inclusion criteria was met in 262 patients (302 hips). Data was collected after reviewing the chart, and reports and radiographic measurements, including Dorr type and canal fit ratios, were obtained from preoperative and postoperative radiographs, respectively. RESULTS: A total of 302 total hips were included, 161 patients were male (53.3%) and 141 were female (46.7%), with an average age of 66.5 years (27-88, +/- 10.7 years). Average follow up was 0.3 years (range, 0.05-1.71 years). The majority of patients had a Dorr B femur (81.7%). The Median stem size used was an 8 (range, 2-15), and 89.4% of those had a collar. Average canal fill ratio was 0.83 (range, 0.43-0.98, +/- 0.07). Overall, there were two Vancouver B2a periprosthetic femoral shaft fractures (0.66%) that required revision surgery to a modular stem. In addition, there were two Vancouver Ag greater trochanteric fractures (0.66%) with acceptable alignment that did not require revision surgery. Demographic information about the patients with femoral complications is summarized in Table I. Average age of patients with femoral complications was 69.5 years, with an average canal fit ratio of 0.88. CONCLUSION: We found that the triple-wedge implant had a low rate of early femoral complication in primary THA from an anterior approach and is safe for use in THA from a DAA. More follow up is needed to evaluate continuing implant survivorship and patient outcomes.

Systems Biology Approach Identifies Prognostic Signatures of Poor Overall Survival and Guides the Prioritization of Novel BET-CHK1 Combination Therapy for Osteosarcoma.

Osteosarcoma (OS) patients exhibit poor overall survival, partly due to copy number variations (CNVs) resulting in dysregulated gene expression and therapeutic resistance. To identify actionable prognostic signatures of poor overall survival, we employed a systems biology approach using public databases to integrate CNVs, gene expression, and survival outcomes in pediatric, adolescent, and young adult OS patients. Chromosome 8 was a hotspot for poor prognostic signatures. The MYC-RAD21 copy number gain (8q24) correlated with increased gene expression and poor overall survival in 90% of the patients (n = 85). MYC and RAD21 play a role in replication-stress, which is a therapeutically actionable network. We prioritized replication-stress regulators, bromodomain and extra-terminal proteins (BETs), and CHK1, in order to test the hypothesis that the inhibition of BET + CHK1 in MYC-RAD21+ pediatric OS models would be efficacious and safe. We demonstrate that MYC-RAD21+ pediatric OS cell lines were sensitive to the inhibition of BET (BETi) and CHK1 (CHK1i) at clinically achievable concentrations. While the potentiation of CHK1i-mediated effects by BETi was BET-BRD4-dependent, MYC expression was BET-BRD4-independent. In MYC-RAD21+ pediatric OS xenografts, BETi + CHK1i significantly decreased tumor growth, increased survival, and was well tolerated. Therefore, targeting replication stress is a promising strategy to pursue as a therapeutic option for this devastating disease.

Role of radiation therapy for pediatric upper extremity extraskeletal osteosarcoma: A case series.

BACKGROUND: Extraskeletal osteosarcoma is an extremely rare disease, comprising less than 0.1% of all cancers diagnosed in the United States, of which less than 5% occur in the upper extremities. The management of two cases of pediatric upper extremity extraskeletal osteosarcoma is discussed. CASE DESCRIPTION: Two children initially noticed painless left upper extremity masses at the ages of 16 and 13, respectively. Following a period of several months, both lesions became symptomatic, necessitating operative intervention, which revealed giant cell-rich extraskeletal osteosarcoma; PET staging following gross total resection revealed no residual or metastatic disease in either patient. After extensive discussion with the patients and family, adjuvant chemotherapy was initiated for one patient, and adjuvant radiation therapy was initiated in both patients. CONCLUSIONS: Despite the rarity of these tumors, the importance of radiation therapy has been established by current and ongoing studies such as the Children's Oncology Group study ARST0332. Radiation therapy remains an important component of the multimodality therapy comprising optimal treatment of this disease, despite the relative paucity of long-term outcome data derived from level I evidence.

Transformation of Ischial Osteoblastoma Into High-Grade Osteoblastoma-Like Osteosarcoma.

The authors report an osteoblastoma-like variant of osteosarcoma of the right ischial tuberosity in a 14-year-old boy. Radiographs initially showed a bone-forming lesion of the right ischial tuberosity. The patient underwent biopsy with curettage and bone grafting, with final pathology revealing osteoblastoma. Two years after the initial procedure, he presented with exuberant bone formation about the operative site concerning for recurrence. He underwent a second biopsy that showed transformation into a high-grade osteoblastoma-like osteosarcoma. Results from staging studies were negative for distant metastatic disease. The patient was treated with standard 3-drug chemotherapy along with wide resection of the right ischium with periacetabular reconstruction and total hip arthroplasty. [Orthopedics. 2019; 42(3):e343-e345.].

Novel Technique for Treatment of Calcaneal Tuberosity Fractures.

Calcaneal tuberosity fractures comprise only 1% to 2% of all calcaneal fractures. Treatment of these injuries has traditionally included open reduction and internal fixation with various means including lag screws, suture anchors, and K-wires. This article reports on a series of cases treated with excision of the tuberosity fragment with repair of the Achilles tendon supplemented by a flexor hallucis longus tendon transfer.

Do Surgical Margins Affect Local Recurrence and Survival in Extremity, Nonmetastatic, High-grade Osteosarcoma?

BACKGROUND: Long-term survival for all patients with osteosarcoma using current aggressive adjuvant chemotherapy and surgical resection is between 60% and 70%. In patients who present with nonmetastatic, high-grade extremity osteosarcoma of bone, limb salvage surgery is favored, when appropriate, over amputation to preserve the limb, because limb salvage may lead to a superior quality of life compared with amputation. However, concern remains that in the attempt to preserve the limb, close or microscopically positive surgical margins may have an adverse effect on event-free survival. QUESTIONS/PURPOSES: (1) Does a positive or close surgical margin increase the likelihood of a local recurrence? (2) Does a positive or close surgical margin adversely affect the development of metastatic disease? (3) What is the relationship of surgical margin on overall survival? METHODS: With institutional review board approval, we retrospectively evaluated 241 patients treated at our institution between 1999 and 2011. Exclusion criteria included nonextremity locations, metastatic disease at initial presentation, low- or intermediate-grade osteosarcoma, treatment regimens that did not follow National Comprehensive Cancer Network (NCCN) guidelines, incomplete medical records, and any part of treatment performed outside of Moffitt Cancer Center or All Children's Hospital. Fifty-one patients were included in the final analysis, of whom 31 (61%) had followup data at a minimum of 2 years or whose clinical status was known but had died before 2 years of followup. Margin status was defined as (1) microscopically positive; (2) negative ≤ 1 mm; and (3) negative > 1 mm. Margin status, histologic response (tumor percent necrosis), type of osteosarcoma, type of surgery, presence of local recurrence, metastatic disease, and overall survival were recorded for each patient. The mean age was 22 years (range, 12-74 years) and the mean followup was 3 years (range, 0.1-14 years). Margin status was positive in 10% (five of 51), negative ≤ 1 mm 26% (13 of 51), and negative > 1 mm 65% (33 of 51). RESULTS: Local recurrence was noted to be 14% (seven of 51) at 3.4 years. After controlling for relevant confounding variables, the presence of a positive margin compared with a negative margin > 1 mm was the only independent predictor of local recurrence (hazard ratio [HR], 8.006; 95% confidence interval [CI], 1.314-48.781; p = 0.0241). At a mean of 3.4 years, 29% (15 of 51) of the patients developed metastatic disease with no difference with the numbers available in the probability of developing metastatic disease among the three margin groups (p = 0.614). Overall survival at 3.8 years was 75% (38 of 51). After controlling for relevant confounding variables, we found that patients with positive margins were more likely to die from disease than those with negative margins (HR, 6.26; 95% CI, 1.50-26.14; p = 0.0119); no other independent predictors of survival were identified. CONCLUSIONS: With the numbers of patients we had, we observed that patients with extremity, nonmetastatic, high-grade osteosarcoma who had positive margins showed a higher probability of local recurrence in comparison to those with negative surgical margins. Given that positive margins appear to be associated with poorer survival in patients with high-grade osteosarcoma of the extremities, surgeons should strive to achieve negative margins, but larger studies are needed to confirm these findings. LEVEL OF EVIDENCE: Level III, therapeutic study.

Vascularized fibular grafts for avascular necrosis after slipped capital femoral epiphysis: is hip preservation possible?

BACKGROUND: Avascular necrosis (AVN) of the femoral head is a potential complication in patients with slipped capital femoral epiphysis (SCFE), radiographically occurring in 3-60%. This may lead to early hip fusion or hip arthroplasty. Free vascularized fibular grafting (FVFG) may provide a reasonable means to preserve the femoral head. QUESTIONS/PURPOSES: We asked: (1) What percentage of patients with AVN after SCFE treated with FVFG underwent subsequent THA or hip fusion and what was the lifespan of the FVFG? (2) Did the graft survival rate of FVFG for AVN after SCFE coincide with historically reported rates of FVFG for idiopathic AVN? And (3) did hip function improve after FVFG? METHODS: We retrospectively reviewed 52 patients who underwent FVFG for SCFE. We calculated the longevity of the graft and factors associated with graft survival. Harris hip scores (HHS) were recorded pre- and postoperatively. Minimum followup was 1 month (median, 19 months; range, 1-136 months). RESULTS: Five of the 52 patients (10%) underwent conversion to THA (four) or hip fusion (one). Mean age was greater in these patients than in those not requiring further procedures: 16 versus 13 years. Median graft survival time before arthroplasty/fusion was 12 years (range, 2-16 years) while it is currently 8 years (range, 2-16 years) in patients not undergoing subsequent procedures. HHSs improved 35 points on average (38 points preoperatively to 73 points postoperatively). CONCLUSIONS: In patients undergoing FVFG for AVN secondary to SCFE, 90% have maintained their native hips for 8 years with improved hip function, similar to other published reports of FVFG. Further followup is needed of patients currently retaining their FVFGs as to eventual conversion to THA or fusion. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Metal-metal hip resurfacing: solution to a nonexistent problem.

Second-decade survivorship may not be as predictable for total hip resurfacing as for THA. The operation requires more surgical exposure and is more difficult to perform reliably than a large-head metal-on-metal THA. Perhaps we have solved some of our prior dilemmas and created some new risks for the future with hip resurfacing arthroplasty, with many questions remaining unanswered. For now, we will stick with what works and solves real clinical problems for both the surgeon and the patient: the conventional THA with a large-head metal-on-metal articulation.