Modernizing Our Understanding of Total Hip Arthroplasty in the Pediatric and Young Adult Patient: A Single-center Experience.

INTRODUCTION: Pediatric hip disorders represent a broad range of pathology and remain a significant source of morbidity for children and young adults. Surgical intervention is often required for joint preservation, but when salvage is not possible, joint replacement may be indicated to eliminate pain and preserve function. Although there have been significant updates in the management of both pediatric hip disease and the field of total hip arthroplasty (THA), there is a paucity of literature reflecting advancements in the area of pediatric and young adult (PYA) arthroplasty. No study has investigated the impact of approach on outcomes after PYA THA. The purpose of this study is to describe the indications, techniques, and early outcomes of THA in the PYA population in a modern practice setting. METHODS: We performed a retrospective descriptive analysis of all patients undergoing primary THA performed at a tertiary care children's hospital from 2004 to 2019. Ninety-three hips in 76 patients were evaluated. Demographics, intraoperative variables, postoperative pain and function ratings, and complication and revision rates were collected. RESULTS: Eighty-five hips in 69 patients were included. Patients were aged 12 to 23 years old, with males and females represented equally (33 vs. 36, respectively). The most common cause of hip pain was avascular necrosis (AVN, 56/85, 66%), most commonly due to slipped capital femoral epiphysis (13/56, 23%) idiopathic AVN (12/56, 21%), and chemotherapy (12/56, 21%). Half of all hips had been previously operated before THA (43/85). Thirty-six procedures were performed via the posterolateral approach (36/85, 42%), 33 were performed via direct anterior approach (33/85, 39%), and 16 were performed via the lateral approach (LAT, 16/85, 19%). At final follow-up, 98% (83/85) of patients had complete resolution of pain, 82% (70/85) had no notable limp, and 95% (81/85) had returned to all activities. There were 6 complications and 1 early revision. Average Hip disability and Osteoarthritis Outcomes Score for Joint Replacement scores increased by 37 points from 56 to 93. The overall revision-free survival rate for PYA THA was 98.8% (at average 19-mo follow-up). CONCLUSIONS: Modern PYA THA is dissimilar in indications and surgical techniques to historic cohorts, and conclusions from prior studies should not be generalized to modern practice. In our practice, PYA patients most commonly carry a diagnosis of AVN, and THA can be performed with modern cementless fixation with large cup and head sizes and ceramic-on-cross-linked polyethylene bearings utilizing any approach. Further study is required to better characterize middle-term and long-term results and patient-reported outcomes. LEVEL OF EVIDENCE: Therapeutic Level IV-retrospective case series.

Primary Knee Intra-articular Synovial Sarcoma in Pediatric and Adolescent Patients.

Synovial sarcoma (SS) arising within a knee joint is extremely rare, with 10 reported cases in pediatric and adolescent patients in English literature. Its rarity and nonspecific clinical and radiological features pose a diagnostic challenge. We present two cases of primary intra-articular SS of left knee to enhance awareness of this entity. One patient is a 17-year-old male complained of left knee pain and gait abnormality for 9 years. The other one is a 13-year-old female presented with left knee pain for one year. Both cases were clinically diagnosed as benign joint lesion and underwent biopsies. Histological examination, immunohistochemical staining and molecular study confirmed that both patients had primary intra-articular SS, monophasic spindle cell type. Intraarticular SS should be considered as a potential diagnosis with unexplained long-standing knee pain.

Prognostic value of necrosis after neoadjuvant therapy for soft tissue sarcoma.

BACKGROUND AND OBJECTIVES: While treatment-induced tissue necrosis is a well-documented predictor of patient survival in malignant bone tumors, its prognostic value in soft tissue sarcomas is controversial. A prior study from our institution did not find a prognostic value to tumor necrosis. We analyze a more extensive database of high-grade soft tissue sarcomas treated with neoadjuvant chemotherapy, radiation therapy, or both to re-evaluate if the degree of tumor necrosis alone can be used as a predictive factor for local recurrence, metastasis, and disease-specific survival. METHODS: Two hundred and seven patients with high-grade extremity soft tissue sarcoma received neoadjuvant chemotherapy and/or radiation therapy and wide excision. Tumor treatment response was determined by histopathologic analysis, and patients were followed for local recurrence, metastasis, or death. RESULTS: Tumor necrosis ≥ 90% correlates with improved disease-free survival with univariate analysis, but this does not reach statistical significance on multivariate analysis. Age and tumor volume were found to be the only independent predictors of disease-free survival on multivariate analysis. CONCLUSIONS: There is insufficient evidence to support the use of necrosis to prognosticate survival and alter chemoradiation regimens in high grade soft tissue sarcomas of the extremity. Larger studies are needed to definitively address the prognostic value of necrosis. LEVEL OF EVIDENCE: Level II, Prognostic

Moving beyond response criteria: new measures of success in the treatment of sarcomas.

There is an urgent need to develop new therapies for soft tissue sarcomas. Traditional cytotoxic therapies, such as doxorubicin and ifosfamide, have been the standard approach to this disease. However, newer paradigms are emerging that are less toxic while targeting dysregulated pathways, tumor hypoxia, and genetic translocations. These newer therapies require different measures of activity as standard response criteria may inaccurately measure their effectiveness. Serious consideration of select endpoints and measures of tumor response are crucial to make significant strides in the treatment of sarcomas. Current studies on soft tissue sarcomas are slowly abandoning response rates while employing progression-free survival and time to progression as improved endpoints. With time and data, our understanding of the relative activity of these agents will grow and lead to improved benefits for our patients.

Endoprostheses last longer than intramedullary devices in proximal femur metastases.

BACKGROUND: The proximal femur is the most common site of surgery for bone metastases, and stabilization may be achieved through intramedullary fixation (IMN) or endoprosthetic reconstruction (EPR). Intramedullary devices are less expensive, less invasive, and may yield improved function over endoprostheses. However, it is unclear which, if either, has any advantages. QUESTIONS/PURPOSES: We determined whether function, complications, and survivorship differed between the two approaches. METHODS: We retrospectively reviewed 158 patients with 159 proximal femur metastatic lesions treated with surgical stabilization. Forty-six were stabilized with IMN and 113 were treated with EPR. The minimum followup was 0.25 months (mean, 16 months; median, 17 months; range, 0.25-86 months). RESULTS: The mean Musculoskeletal Tumor Society score was 24 of 30 (80%) after IMN and 21 of 30 (70%) after EPR. There were 12 complications (26%) in the IMN group, including 10 nonunions, six of which went on to mechanical failure. There were complications in 20 of 113 (18%) of the EPR group, which consisted of 10 dislocations (9%) and 10 infections (9%). There were no mechanical failures with EPR. Both implants remained functional for the limited lifespan of these patients in each group at all time intervals. EPRs were associated with increased implant longevity compared with IMNs (100% versus 85% 5-year survival, respectively) and a decreased rate of mechanical failure (0% versus 11%, respectively) when compared with the intramedullary devices. CONCLUSIONS: Patients with metastatic disease to the proximal femur may live for long periods of time, and these patients may undergo stabilization with either IMN or EPR with comparable functional scores and the implant survivorship exceeding patient survivorship at all time intervals. Endoprostheses demonstrate a lower mechanical failure rate and a higher rate of implant survivorship without mechanical failure than IMN devices. LEVEL OF EVIDENCE: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

A meta-analysis of osteosarcoma outcomes in the modern medical era.

Four decades ago, specialized chemotherapy regimens turned osteosarcoma, once considered a uniformly fatal disease, into a disease in which a majority of patients survive. Though significant survival gains were made from the 1960s to the 1980s, further outcome improvements appear to have plateaued. This study aims to comprehensively review all significant, published data regarding osteosarcoma and outcome in the modern medical era in order to gauge treatment progress. Our results indicate that published survival improved dramatically from 1960s to 1980s and then leveled, or in some measures decreased. Recurrence rates decreased in the 1970s and then leveled. In contrast, published limb salvage rates have increased significantly every recent decade until the present. Though significant gains have been made in the past, no improvement in published osteosarcoma survival has been seen since 1980, highlighting the importance of a new strategy in the systemic management of this still very lethal condition.

Factors, treatments, and outcomes associated with primary soft tissue malignancies of the forearm: A series of 31 cases.

BACKGROUND: Primary soft tissue malignancies of the forearm constitute up to 24% of soft tissue extremity malignancies and present a difficult problem when attempting to preserve both life and forearm function. As described by Enneking, recurrence and metastasis are the two largest contributors to morbidity and mortality and therefore, the primary consideration must be to excise the entire tumor. However, since limb salvage is the preferred treatment over amputation in 95% of cases, many physicians elect to perform marginal resections over wide resections in the attempt to increase functional outcomes. Our study aimed to compare recurrence rates and forearm functional outcomes between these groups to better guide clinical decision making. QUESTIONS/PURPOSES: (1) What is the difference in recurrence rates between wide resection of the tumor and marginal resection? (2) Between wide and marginal resection groups, what is the functional difference as measured by MSTS functional outcome scores? The purpose of our study was to answer these two questions and better understand if marginal resection yielded better results compared to wide resection. PATIENTS AND METHODS: Following IRB approval, we conducted a retrospective case series between 1999 and 2019. Included in the study were patients with a primary malignancy in the predetermined borders of the forearm with a minimum of two-year follow up post-operatively. All patients in the study were operated on by physicians in the Southern California Kaiser Permanente system. Thirty-one patients met criteria for the study. Recurrence rates and metastatic disease was determined through serial history and physical examination, with patients undergoing magnetic resonance (MRI) imaging of the affected area and computed tomography (CT) of the chest every 6 months for the first 2 years, and every 12 months for the following 3 years. MSTS scores were obtained in subsequent follow-ups following the guidelines set by the MSTS scoring system. RESULTS: Of the 31 patients evaluated, 4 (12.9%) had recurrence and 2 (6.5%) had signs of metastasis. Between the marginal excision and wide excision groups, all 4 recurrences happened in the marginal excision group and none occurred in the wide excision group. In addition, in the pathology report, excisions with 0.1 cm margins or less on any side had 3 instances of recurrence (31%) whereas there was only 1 recurrence (4.8%) outside of this group. MSTS scores for both wide excision and marginal excision were within 1 point with average scores being 26 and 26.9, respectively. CONCLUSIONS: Consistent with the literature, our study found that closer surgical margins lead to higher rates of recurrence due to the increased likelihood of aberrant tumor. However, when looking at functional outcome scores, we found minimal benefit in marginal resections compared to wide resections. The lack of MSTS score difference between both groups highlighted that the perceived benefit of choosing a marginal resection over wide excision may be nominal at best. Therefore, we recommend performing an additional intraoperative resection on narrow margins to reduce the chance of recurrence. Of note, clinical discernment in the form of preserving valuable neurovascular structures such as the median nerve should still be an important consideration.

A comparison of fine-needle aspiration, core biopsy, and surgical biopsy in the diagnosis of extremity soft tissue masses.

BACKGROUND: Biopsy tissue can be obtained through a fine needle, a wider coring needle, or through an open surgical incision. Though much literature exists regarding the diagnostic yield of these techniques individually, none compare accuracy of diagnosis in the same mass. QUESTIONS/PURPOSES: We asked how the diagnostic accuracy of fine-needle aspiration, core biopsy, and open surgical biopsy compare in regard to identifying malignancy, establishing the exact diagnosis, and guiding the appropriate treatment of soft tissue masses. PATIENTS AND METHODS: We prospectively studied 57 patients with palpable extremity soft tissue masses, performing fine-needle aspiration, followed by core biopsy, followed by surgical biopsy of the same mass. RESULTS: Open surgical biopsy was 100% accurate on all accounts. With regard to determining malignancy, fine-needle aspiration and core biopsy had 79.17% and 79.2% sensitivity, 72.7% and 81.8% specificity, 67.9% and 76% positive predictive value, 82.8% and 84.4% negative predictive value, and an overall accuracy of 75.4% and 80.7%, respectively. In regard to determining exact diagnosis, fine-needle aspiration had a 33.3% accuracy and core biopsy had a 45.6% accuracy. With regard to eventual treatment, fine-needle aspiration was 38.6% accurate and core biopsy was 49.1% accurate. CONCLUSIONS: In soft tissue mass diagnosis, core biopsy is more accurate than fine-needle aspiration on all accounts, and open biopsy is more accurate than both in determining malignancy, establishing the exact diagnosis, and the guiding appropriate treatment.

Microbiology of bone and joint infections in injecting drug abusers.

BACKGROUND: The literature contains variable reports on the causative organisms of osteomyelitis and septic arthritis in patients with injecting drug abuse and on the rate of oxacillin-resistant S aureus. It is important to have a clear notion of the organisms to initiate empiric antimicrobial therapy. QUESTIONS/PURPOSES: We therefore determined the spectrum of organisms in bone and joint infections in patients who were injecting drug users. METHODS: We retrospectively reviewed the medical records of 215 patients (154 male, 61 female) with a history of injecting drug abuse and concurrent bone and/or joint infection from 1998 to 2005. The mean age was 43 years (range, 23-83 years). Osteomyelitis was present in 127 of the 215 patients (59%), septic arthritis in 53 (25%), and both in 35 (16%). The lower extremity was most commonly involved (141 cases, 66%), with osteomyelitis of the tibia present in 70 patients (33%) and septic knee arthritis in 30 patients (14%). RESULTS: Cultures yielded predominately Gram-positive bacteria: Staphylococcus aureus in 52% and coagulase-negative Staphylococcus in 20%. The proportion of oxacillin-resistant S aureus among S aureus infections increased from 21% in 1998 to 73% in 2005. Gram-negative organisms were present in 19% of infections and anaerobes in 13%. Patients with osteomyelitis had a higher prevalence of polymicrobial infections (46% versus 15%), infections due to Gram-negative organisms (24% versus 9%), and anaerobic infections (19% versus 6%) compared to patients with septic arthritis. CONCLUSIONS: These findings suggest broad-spectrum empiric antibiotic therapy, including vancomycin, should be considered for bone and joint infections in patients with injecting drug abuse. LEVEL OF EVIDENCE: Level IV, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.

The linear cutting stapler may reduce surgical time and blood loss with muscle transection: a pilot study.

UNLABELLED: Because of skeletal muscle's density and vascularity, its transection with standard electrocautery can be tedious. In a pilot study we asked whether a linear cutting stapling device decreased surgical time, blood loss, transfusion rates, and complications in patients undergoing above-knee amputation when compared to traditional electrocautery. We retrospectively reviewed 11 patients with above-knee amputation cases using a linear cutting stapling device over a 10-year period and compared those to 13 patients in whom we used electrocautery. The patients treated with the linear cutting stapling device had an average of 97 minutes of surgical time, 302 cc blood loss, and 1.55 units transfusion, compared to an average 119 minutes, 510 cc, and 2.15 units, respectively, with the electrocautery cases. Despite the trends, these parameters, as well as major complications, were similar in these two small groups. In skeletal muscle transection, we believe the linear cutting stapler is a reasonable and potentially cost-effective technical alternative to electrocautery, possibly resulting in less blood loss and shorter surgical time with similar rates of complications. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Periacetabular reconstruction with a new endoprosthesis.

UNLABELLED: Reconstruction of the Type II pelvic resection is challenging. Currently available reconstructive options have inherent problems including graft and implant failure, pain, poor function, and high major complication rates. The periacetabular reconstruction (PAR) endoprosthesis was designed to be secured with internal fixation and bone cement to the remaining ilium and support a reconstructed acetabulum. This construct potentially avoids the complications of graft or hardware failure, while maintaining early mobilization, comfort, limb lengths, and function. We retrospectively reviewed 25 patients who underwent Type II pelvic resection and reconstruction with the PAR endoprosthesis, analyzing function, complications, and survivorship. The minimum followup was 13 months (mean, 29.4 months; range, 13 to 108 months). We compared the PAR data with the literature for the Mark II saddle endoprosthesis. The PAR's average MSTS score was 20.8 (67%), major complications occurred in 14 (56%), and implant survivorship was 84% at 2 years and 60% at 5 years. The rate of failure at the ilium-saddle interface was lower and implant survivorship higher than those in the published literature for the Mark II saddle. We recommend use of the PAR endoprosthesis for reconstruction of large defects following Type II pelvic resection. The modified saddle design provides greater inherent stability, allowing for faster rehabilitation and improved longevity without increased complications and is an improvement over the currently available saddle prostheses. LEVEL OF EVIDENCE: Level III, retrospective case series. See Guidelines for Authors for a complete description of levels of evidence.

Clavicular eosinophilic granuloma causing adult shoulder pain.

Though rarely reported, neoplasms of the clavicle occur, and their symptoms can be mistaken for more common shoulder conditions. We present the case of a benign clavicular neoplasm, rarely seen in adults, presenting with pain, and eventual pathologic fracture in a 49 year-old. A 49 year-old male firefighter underwent arthroscopic rotator cuff repair for shoulder pain after magnetic resonance imaging revealed supraspinatus tendon tear. The patient's pain persisted after surgery, and was described as routine until he developed severe pain after minor blunt trauma. A local Emergency Room performed the first x-rays, which revealed a pathologic fracture of the distal clavicle through a destructive lesion. The patient was referred to an orthopedic oncologist, who performed incisional biopsy, which initially diagnosed osteomyelitis. The patient was subsequently taken to surgery for debridement. Pathology then yielded the diagnosis of eosinophilic granuloma. The patient was taken back to surgery for formal curettage with open reduction and internal fixation. The patient's pain resolved, the pathologic fracture fully healed, and the patient returned to full time work as a firefighter. Though workup for common shoulder conditions often identifies incidental benign lesions of bone, the converse can be true. Persistent pain despite intervention should raise concern for further investigation. An x-ray alone can reveal a destructive bone lesion as the source of shoulder pain.