Rose, Peter S.

Soft tissue aneurysmal bone cysts (STABCs) are rare neoplasms histopathologically identical to aneurysmal bone cysts. These benign lesions are characterized by thin, peripheral ossification and no skeletal continuity. STABC may be difficult to distinguish from myositis ossificans (MO) and malignant entities from imaging and fine needle aspiration, due to rarity and overlapping features. We present a case of a STABC occurring in the paraspinal cervical muscles. The imaging, histopathology, molecular analysis, and treatment are discussed. Four other published cases of STABC of the head and neck are reviewed.

AimsVenous tumour thrombus (VTT) is a rare finding in osteosarcoma. Despite the high rate of VTT in osteosarcoma of the pelvis, there are very few descriptions of VTT associated with extrapelvic primary osteosarcoma. We therefore sought to describe the prevalence and presenting features of VTT in osteosarcoma of both the pelvis and the limbs.MethodsRecords from a single institution were retrospectively reviewed for 308 patients with osteosarcoma of the pelvis or limb treated between January 2000 and December 2022. Primary lesions were located in an upper limb (n = 40), lower limb (n = 198), or pelvis (n = 70). Preoperative imaging and operative reports were reviewed to identify patients with thrombi in proximity to their primary lesion. Imaging and histopathology were used to determine presence of tumour within the thrombus.ResultsTumours abutted the blood vessels in 131 patients (43%) and encased the vessels in 30 (10%). Any form of venous thrombus was identified in 31 patients (10%). Overall, 21 of these thrombi were determined to be involved with the tumour based on imaging (n = 9) or histopathology (n = 12). The rate of VTT was 25% for pelvic osteosarcoma and 1.7% for limb osteosarcoma. The most common imaging features associated with histopathologically proven VTT were enhancement with contrast (n = 12; 100%), venous enlargement (n = 10; 83%), vessel encasement (n = 8; 66%), and visible intraluminal osteoid matrix (n = 6; 50%). Disease-specific survival (DSS) for patients with VTT was 95% at 12 months (95% CI 0.87 to 1.00), 50% at three years (95% CI 0.31 to 0.80), and 31% at five years (95% CI 0.14 to 0.71). VTT was associated with worse DSS (hazard ratio 2.3 (95% CI 1.11 to 4.84).ConclusionVTT is rare with osteosarcoma and occurs more commonly in the pelvis than the limbs. Imaging features suggestive of VTT include enhancement with contrast, venous dilation, and vessel encasement. VTT portends a worse prognosis for patients with osteosarcoma, with a similar survivability to metastatic disease.Cite this article: Bone Joint J 2024;106-B(8):865–870.

Abstract Background Radiation‐associated soft tissue sarcomas (RA‐STS) are rare complications of patients receiving radiation therapy (RT) and are generally associated with a poor prognosis. Most of the literature surrounding RA‐STS of the chest is centered on angiosarcoma. Therefore, we aim to document the management and outcome of patients with non‐angiosarcoma RA‐STS of the chest. Methods We reviewed 17 patients (all female, median age 65 years) diagnosed with RA‐STS. The most common primary malignancy was breast carcinoma ( n = 15), with a median RT dose of 57.9 Gy. All patients underwent surgical resection; five patients (29%) received radiotherapy; and five patients (29%) received peri‐operative chemotherapy. Results The 5‐year local recurrence and metastatic‐free survival were 61% and 60%, while the 5‐year disease‐specific survival was 53%. Local recurrence was associated with death due to disease (HR 9.06, p = 0.01). Complications occurred in nine of patients, most commonly due to a wound complication ( n = 7). At the most recent follow‐up, the median Musculoskeletal Tumor Society Score was 63%. Conclusion RA‐STS involving the chest wall are aggressive tumors with a high risk of local relapse and death due to disease. Local recurrence was associated with death due to disease; as such, we recommend aggressive surgical management with evaluation for adjuvant therapies.

Abstract Background Endoprostheses (EPC) are often utilized for reconstruction of the proximal humerus with either hemiarthroplasty (HA) or reverse arthroplasty (RA) constructs. RA constructs have improved outcomes in patients with primary lesions, but no studies have compared techniques in metastatic disease. The aim of this study is to compare functional outcomes and complications between HA and RA constructs in patients undergoing endoprosthetic reconstruction for proximal humerus metastases. Methods We retrospectively reviewed our institutional arthroplasty database to identify 66 (56% male; 38 HA and 28 RA) patients with a proximal humerus reconstruction for a non‐primary malignancy. The majority (88%) presented with pathologic fracture, and the most common diagnosis was renal cell carcinoma (48%). Resultss Patients with RA reconstructions had better postoperative forward elevation (74° vs. 32°, p < 0.01) and higher functional outcome scores. HA patients had more complications (odds ratio 13, p < 0.01), with instability being the most common complication. Conclusions Patients with nonprimary malignancies of the proximal humerus had improved functional outcomes and fewer complications after undergoing reconstruction with a reverse EPC compared to a HA EPC. Preference for reverse EPC should be given in patients with good prognosis and ability to complete postoperative rehabilitation.

OBJECTIVE Chordomas are rare tumors of the skull base and spine believed to arise from the vestiges of the embryonic notochord. These tumors are locally aggressive and frequently recur following resection and adjuvant radiotherapy. Proton therapy has been introduced as a tissue-sparing option because of the higher level of precision that proton-beam techniques offer compared with traditional photon radiotherapy. This study aimed to compare recurrence in patients with chordomas receiving proton versus photon radiotherapy following resection by applying tree-based machine learning models. METHODS The clinical records of all patients treated with resection followed by adjuvant proton or photon radiotherapy for chordoma at Mayo Clinic were reviewed. Patient demographics, type of surgery and radiotherapy, tumor recurrence, and other variables were extracted. Decision tree classifiers were trained and tested to predict long-term recurrence based on unseen data using an 80/20 split. RESULTS Fifty-three patients with a mean ± SD age of 55.2 ± 13.4 years receiving surgery and adjuvant proton or photon therapy to treat chordoma were identified; most patients were male. Gross-total resection was achieved in 54.7% of cases. Proton therapy was the most common adjuvant radiotherapy (84.9%), followed by conventional or external-beam radiation therapy (9.4%) and stereotactic radiosurgery (5.7%). Patients receiving proton therapy exhibited a 40% likelihood of having recurrence, significantly lower than the 88% likelihood observed in those treated with nonproton therapy. This was confirmed on logistic regression analysis adjusted for extent of tumor resection and tumor location, which revealed that proton adjuvant radiotherapy was associated with a decreased risk of recurrence (OR 0.1, 95% CI 0.01–0.71; p = 0.047) compared with photon therapy. The decision tree algorithm predicted recurrence with an accuracy of 90% (95% CI 55.5%–99.8%), with the lowest risk of recurrence observed in patients receiving gross-total resection with adjuvant proton therapy (23%). CONCLUSIONS Following resection, adjuvant proton therapy was associated with a lower risk of chordoma recurrence compared with photon therapy. The described machine learning models were able to predict tumor progression based on the extent of tumor resection and adjuvant radiotherapy modality used.

AimsThe sacroiliac joint (SIJ) is the only mechanical connection between the axial skeleton and lower limbs. Following iliosacral resection, there is debate on whether reconstruction of the joint is necessary. There is a paucity of data comparing the outcomes of patients undergoing reconstruction and those who are not formally reconstructed.MethodsA total of 60 patients (25 females, 35 males; mean age 39 years (SD 18)) undergoing iliosacral resection were reviewed. Most resections were performed for primary malignant tumours (n = 54; 90%). The mean follow-up for surviving patients was nine years (2 to 19).ResultsOverall, 27 patients (45%) were reconstructed, while 33 (55%) had no formal reconstruction. There was no difference in the use of chemotherapy (p = 1.000) or radiotherapy (p = 0.292) between the groups. Patients with no reconstruction had a mean larger tumour (11 cm (SD 5) vs 8 cm (SD 4); p = 0.014), mean shorter operating times (664 mins (SD 195) vs 1,324 mins (SD 381); p = 0.012), and required fewer blood units (8 (SD 7) vs 14 (SD 11); p = 0.012). Patients undergoing a reconstruction were more likely to have a deep infection (48% vs 12%; p = 0.003). Nine reconstructed patients had a hardware failure, with five requiring revision. Postoperatively 55 (92%) patients were ambulatory, with no difference in the proportion of ambulatory patients (89% vs 94%; p = 0.649) or mean Musculoskeletal Tumor Society Score (59% vs 65%; p = 0.349) score between patients who did or did not have a reconstruction. The ten-year disease-specific survival was 69%, with no difference between patients who were reconstructed and those who were not (78% vs 45%; p = 0.316). There was no difference in the rate of metastasis between the two groups (hazard ratio (HR) 2.78; p = 0.102).ConclusionOur results demonstrate that SIJ reconstruction is associated with longer operating times, greater need for blood transfusion, and more postoperative infections, without any improvement in functional outcomes when compared to patients who did not have formal SIJ reconstruction.Cite this article: Bone Joint J 2024;106-B(1):93–98.

BACKGROUND: Using standard anterior approaches, consistent R0 resection of locally advanced primary and recurrent rectal and anal cancer involving the deep pelvic sidewall may be unattainable. Therefore, to improve R0 resection rates, we have used a posterior-first, then anterior 2-stage approach to resection of tumors in this location. OBJECTIVE: To assess the R0 resection rate and surgical outcomes of the first 10 patients operated on using this approach. DESIGN: We conducted a retrospective case series review of our prospectively maintained surgical pathology and tumor registries. SETTING: This study was conducted at the Mayo Clinic in Rochester, Minnesota. PATIENTS: Ten patients (6 female individuals, median age 53.5 years) with primary or recurrent anal or rectal cancer treated with a posterior-first, then anterior 2-stage approach were identified. MAIN OUTCOME MEASURES: The primary outcome measures were the R0 resection rate and surgical outcomes. RESULTS: An R0 resection was achieved in all 10 patients. Nine patients developed 1 or more 30-day Clavien-Dindo grade III complications. Nine patients developed gluteal wound complications ranging from superficial wound dehiscence to flap necrosis. During the follow-up period, 4 patients were found to have metastatic disease and 1 patient had local re-recurrence. LIMITATIONS: Small cohort with heterogeneous tumors and a short follow-up duration. CONCLUSION: A posterior-first, then anterior 2-stage approach has allowed us to achieve consistent R0 resection margins in locally advanced primary and recurrent rectal and anal cancers involving the deep pelvic sidewall. Poor wound healing of the posterior gluteal incision is a common complication. See Video Abstract. MEJORANDO LAS TASAS DE RESECCIÓN R0 CON UN ABORDAJE DE DOS ETAPAS PRIMERO POSTERIOR PARA LA RESECCIÓN EN BLOQUE DE CÁNCERES ANORRECTALES PRIMARIOS Y RECURRENTES LOCALMENTE AVANZADOS QUE AFECTAN LA PARED LATERAL PÉLVICA PROFUNDA ANTECEDENTES: Utilizando abordajes anteriores estándares, la resección R0 consistente del cáncer de recto y ano primario y recurrente localmente avanzado involucrando la pared lateral pélvica profunda puede ser inalcanzable. Por lo tanto, para mejorar las tasas de resección R0, hemos empleado un abordaje de 2 etapas primero posterior y luego anterior para la resección de tumores en esta ubicación. OBJETIVO: Este estudio tuvo como objetivo evaluar la tasa de resección R0 y los resultados quirúrgicos de los primeros 10 pacientes operados con este abordaje. DISEÑO: Realizamos una revisión retrospectiva de series de casos de nuestros registros de patología quirúrgica y tumores mantenidos prospectivamente. AJUSTE: Este estudio se realizó en la Clínica Mayo en Rochester, Minnesota, EE. UU. PACIENTES: Se identificaron diez pacientes (6 mujeres, mediana de edad 53.5 años) con cáncer anal o rectal primario o recurrente tratados con un abordaje de dos etapas, primero posterior y luego anterior. PRINCIPALES MEDIDAS DE RESULTADO: Las medidas de resultado primarias fueron la tasa de resección R0 y los resultados quirúrgicos. RESULTADOS: Se logró una resección R0 en los 10 pacientes. Nueve pacientes desarrollaron una o más complicaciones de grado III de Clavien-Dindo a los 30 días. Nueve pacientes desarrollaron complicaciones de la herida del glúteo que variaron desde dehiscencia superficial de la herida hasta necrosis del colgajo. Durante el período de seguimiento, se encontró que 4 pacientes tenían enfermedad metastásica y un paciente tuvo recurrencia local. LIMITACIONES: Cohorte pequeño con tumores heterogéneos y corta duración de seguimiento. CONCLUSIÓN: Un abordaje en 2 etapas, primero posterior y luego anterior, nos ha permitido lograr márgenes de resección R0 consistentes en cánceres de recto y anal primarios y recurrentes localmente avanzados que afectan la pared lateral pélvica profunda. La mala cicatrización de la incisión glútea posterior es una complicación común. (Traducción—Dr. Aurian Garcia Gonzalez)

AimsThe scapula is a rare site for a primary bone tumour. Only a small number of series have studied patient outcomes after treatment. Previous studies have shown a high rate of recurrence, with functional outcomes determined by the preservation of the glenohumeral joint and deltoid. The purpose of the current study was to report the outcome of patients who had undergone tumour resection that included the scapula.MethodsWe reviewed 61 patients (37 male, 24 female; mean age 42 years (SD 19)) who had undergone resection of the scapula. The most common resection was type 2 (n = 34) according to the Tikhoff-Linberg classification, or type S1A (n = 35) on the Enneking classification.ResultsThe ten-year disease-specific survival was 76%. High tumour grade (hazard ratio (HR) 4.27; p = 0.016) and a total resection of the scapula (HR 3.84; p = 0.015) were associated with worse survival. The ten-year metastasis-free and local recurrence-free survivals were 82% and 86%, respectively. Total scapular resection (HR 6.29; p = 0.004) was associated with metastatic disease and positive margins were associated with local recurrence (HR 12.86; p = 0.001). At final follow-up, the mean shoulder forward elevation and external rotation were 79° (SD 62°) and 27° (SD 25°), respectively. The most recent functional outcomes evaluated included the mean Musculoskeletal Tumor Society Score (76% (SD 17%)), the American Shoulder and Elbow Score (73% (SD 20%)), and the Simple Shoulder Test (7 (SD 3)). Preservation of the glenoid (p = 0.001) and scapular spine (p < 0.001) improved clinical outcomes; interestingly, preservation of the scapular spine without the glenoid improved outcomes (p < 0.001) compared to preservation of the glenoid alone (p = 0.05).ConclusionResection of the scapula is a major undertaking with an oncological outcome related to tumour grade, and a functional outcome associated with the status of the scapular spine and glenoid. Positive resection margins are associated with local recurrence.Cite this article: Bone Joint J 2023;105-B(12):1314–1320.

AbstractBackground and ObjectivesRecent studies have reported acceptable outcomes after arthrodesis takedown and conversion to total hip arthroplasty (THA); however, there are no reports on outcomes after oncologic resection, which are inherently complex and may portend poorer outcomes. The purpose of this study was to examine the surgical and functional outcomes of patients who underwent prior hemipelvectomy for tumor resection and were later converted to THA.MethodsAll patients who had prior iliofemoral arthrodesis after oncologic resection that were later converted to THA at a single institution were examined. Charts were reviewed for demographic information, operative information, functional outcomes, and complications/reoperations.ResultsAll three patients in this study were males who underwent internal hemipelvectomies for chondrosarcoma. Patients were converted to THA at a mean of 26 years after arthrodesis. Mean follow‐up after conversion to THA was 7.4 years. During this follow‐up period, two of the three patients required revision surgery. At last follow‐up, the mean Harris Hip Score was 81 and the mean Mayo Hip Score was 67, and all patients were ambulatory without significant pain.ConclusionsOverall, patients who undergo iliofemoral arthrodesis after oncologic hemipelvectomy and are later converted to THA can expect to have a reasonable outcome, despite a high rate of complications and revision surgery.