Transepiphyseal resection for osteosarcoma in patients with open physes using MRI assessment

Hip Preservation and Capanna Reconstruction for Pediatric Proximal Femur Ewing Sarcoma: A Report of 2 Cases

CASE

This is a first report describing preservation of the femoral head by transcervical resection of proximal femoral Ewing sarcoma in 2 pediatric patients. A unique Capanna reconstruction supported joint salvage. At 1 year, Pediatric Outcomes Data Collection Instrument and Pediatric Toronto Extremity Salvage Score outcomes were excellent. Surveillance magnetic resonance imaging was without evidence of recurrence or impaired perfusion to the femoral head.

CONCLUSION

We demonstrate the feasibility of hip joint preservation and maintenance of femoral head viability after transcervical resection of pediatric proximal femur bone sarcomas while preserving the medial circumflex femoral artery. This technique may be a preferred option over joint sacrifice and endoprosthetic replacement in young patients when tumor margins permit.

What to choose in bone tumour resections? Patient specific instrumentation versus surgical navigation: a systematic review

Patient specific instrumentation (PSI) and intraoperative surgical navigation (SN) can significantly help in achieving wide oncological margins while sparing bone stock in bone tumour resections. This is a systematic review aimed to compare the two techniques on oncological and functional results, preoperative time for surgical planning, surgical intraoperative time, intraoperative technical complications and learning curve. The protocol was registered in PROSPERO database (CRD42023422065). 1613 papers were identified and 81 matched criteria for PRISMA inclusion and eligibility. PSI and SN showed similar results in margins (0-19% positive margins rate), bone cut accuracy (0.3-4 mm of error from the planned), local recurrence and functional reconstruction scores (MSTS 81-97%) for both long bones and pelvis, achieving better results compared to free hand resections. A planned bone margin from tumour of at least 5 mm was safe for bone resections, but soft tissue margin couldn't be planned when the tumour invaded soft tissues. Moreover, long osteotomies, homogenous bone topology and restricted working spaces reduced accuracy of both techniques, but SN can provide a second check. In urgent cases, SN is more indicated to avoid PSI planning and production time (2-4 weeks), while PSI has the advantage of less intraoperative using time (1-5 min vs 15-65 min). Finally, they deemed similar technical intraoperative complications rate and demanding learning curve. Overall, both techniques present advantages and drawbacks. They must be considered for the optimal choice based on the specific case. In the future, robotic-assisted resections and augmented reality might solve the downsides of PSI and SN becoming the main actors of bone tumour surgery.

Risk factors for chronic ankle instability after first episode of lateral ankle sprain: A retrospective analysis of 362 cases

BACKGROUND

Chronic ankle instability (CAI) is a common sequela following an acute lateral ankle sprain (LAS). To treat an acute LAS more effectively and efficiently, it is important to identify patients at substantial risk for developing CAI. This study identifies magnetic resonance imaging (MRI) manifestations for predicting CAI development after a first episode of LAS and explores appropriate clinical indications for ordering MRI scans for these patients.

METHODS

All patients with a first-episode LAS who received plain radiograph and MRI scanning within the first 2 weeks after LAS from December 1, 2017 to December 1, 2019 were identified. Data were collected using the Cumberland Ankle Instability Tool at final follow-up. Demographic and other related clinical variables, including age, sex, body mass index, and treatment were also recorded. Univariable and multivariable analyses were performed successively to identify risk factors for CAI after first-episode LAS.

RESULTS

A total 131 out of 362 patients with a mean follow-up of 3.0 ± 0.6 years (mean ± SD; 2.0-4.1 years) developed CAI after first-episode LAS. According to multivariable regression, development of CAI after first-episode LAS was associated with 5 prognostic factors: age (odds ratio (OR) = 0.96, 95% confidence interval (95%CI): 0.93-1.00, p = 0.032); body mass index (OR = 1.09, 95%CI: 1.02-1.17, p = 0.009); posterior talofibular ligament injury (OR = 2.17, 95%CI: 1.05-4.48, p = 0.035); large bone marrow lesion of the talus (OR = 2.69, 95%CI: 1.30-5.58, p = 0.008), and Grade 2 effusion of the tibiotalar joint (OR = 2.61, 95%CI: 1.39-4.89, p = 0.003). When patients had at least 1 positive clinical finding in the 10-m walk test, anterior drawer test, or inversion tilt test, they had a 90.2% sensitivity and 77.4% specificity in terms of detecting at least 1 prognostic factor by MRI.

CONCLUSION

MRI scanning is valuable in predicting CAI after first-episode LAS for those patients with at least 1 positive clinical finding in the 10-m walk test, anterior drawer test, and inversion tilt test. Further prospective and large-scale studies are necessary for validation.

Epiphyseal distraction prior to resection in paediatric bone sarcomas : four decades of experience

Paediatric bone sarcomas are a dual challenge for orthopaedic surgeons in terms of tumour resection and reconstruction, as it is important to minimize functional and growth problems without compromising survival rates. Cañadell's technique consists of a Type I epiphysiolysis performed using continuous distraction by an external fixator prior to resection. It was designed to achieve a safe margin due to the ability of the physeal cartilage to be a barrier to tumour spread in some situations, avoiding the need for articular reconstruction, and preserving the growth capacity most of the times. Despite initial doubts raised in the scientific community, this technique is now widely used in many countries for the treatment of metaphyseal paediatric bone sarcomas. This annotation highlights the importance of Cañadell's work and reviews the experience of applying it to bone sarcoma patients over the last 40 years.Cite this article: Bone Joint J 2023;105-B(1):11-16.

Application of 3-dimensional printing implants for bone tumors

Three-dimensional (3D) additive manufacturing has recently been used in various medical fields. Among them, orthopedic oncology is one that utilizes it most actively. Bone and tumor modeling for surgical planning, personalized surgical instrument fabrication, and implant fabrication are typical applications. The 3D-printed metal implants using titanium alloy powder have created a revolutionary change in bone reconstruction that can be customized to all body areas; however, bioprinting remains experimental and under active study. This review explores the practical applications of 3D printing in orthopedic oncology and presents a representative case. The 3D-printed implant can replace the conventional tumor prosthesis and auto/allobone graft, thereby personalizing bone reconstruction. Biologic bone reconstruction using biodegradable or bioprinted materials beyond metal may be possible in the future.

The safe surgical margin in Ewing's sarcoma

INTRODUCTION

There is recent evidence advocating the use of post-chemotherapy MRI for safe resection of primary bone sarcoma in providing a clear margin of disease. This paper challenges this view by providing evidence obtained from comparing surgical resection margin measurements calculated off the pre- and post-chemotherapy MRIs to the post-operative histological analysis.

METHOD

A retrospective patho-radiological analysis of 10 patients treated for long bone Ewing's sarcoma. The pre- and post-chemotherapy MRI radiological measurements were correlated with the post-operative gross and microscopic histological specimens with the principle aim of determining which represented the accurate histological extent of disease and therefore which image set should be used in determining the surgical resection margins.

RESULTS

In the 10 cases there was a discrepancy in the extent of pathological disease on comparative histological and radiological assessment. The mean age at presentation was 19.5years [4-45 years], with a female bias (n = 7/10). The lower limbs were more commonly involved than the upper limb (femur n = 2/10, tibia n = 3/10, fibula n = 2/10, humerus n = 2/10, ulna n = 1/10). There was no correlation between the percentage reduction in measured volume/length of pathological bone on sequential MRI and the percentage necrosis on histology. The average discrepancy between the length of pathological bone on histology and on MRI was 2.7 cm. Using the baseline pre-chemotherapy MRI to plan the surgical resection margins, 7/10 patients had their surgical resection margins through radiologically clear but pathologically abnormal bone (without histological evidence of residual tumour). Had the post-chemotherapy MRI been used a further 3 patients would have had their tumour resected through pathologically abnormal bone. No patients had or would have had tumour resected through residual tumour.

CONCLUSIONS

The use of the post-chemotherapy MRI for planning surgical resection margins increases the risk of resecting through histologically abnormal bone that may have been previously contaminated by tumour, without significant benefit of preserving sufficient bone to facilitate joint or physeal sparing surgery. The evidence from this study supports current guidelines recommending the use of pre-chemotherapy MRI to plan safe surgical resection margins in Ewing's sarcoma.

Discovery and Characterization of Intercondylar Transphyseal Complexes and their Oncological Significance in Transphyseal Extension of Pediatric Osteosarcoma

Objective

To explore whether there exist undiscovered transphyseal vasculature‐canal compound structures in immature femurs and tibias, and reveal their potential oncological impact.

Methods

This investigation was divided into a morphological study and a clinical study. In the morphological part, a new‐identified anatomic structure was investigated by using radiographical, anatomical, and histological methodologies. Twenty‐eight 1‐mm‐slice thickness magnetic resonance images of pediatric knees were generated and 10 pediatric knees were dissected to verify the existence and universality, observe the radiographic and anatomic characteristics, and determined the located region of this structure. Hematoxylin–eosin staining, immunofluorescence, and angiography procedures were performed to illustrate its histological feature, molecular identification, and vascular origination, respectively. In the clinical part, 38 pediatric osteosarcoma patients were enrolled from January 2014 to December 2020. A descriptive clinical study including 13 typical participants was conducted to investigate the oncological significance of this new‐identified structure. Meanwhile, the discrepancy in transphyseal osteosarcoma extension between different physeal regions was evaluated in a cross‐sectional study.

Results

In the morphological study, we discovered a new‐found vasculature‐canal compound structure, intercondylar transphyseal complex (ITC), which originated from the middle genicular vessels, traversed the whole epiphysis, and breached the intact open physis in the immature proximal tibia or distal femur. The components of ITC included the juxta‐articular, epiphyseal, and transphyseal segments of vessels, the canals that traverse the entire epiphysis and physis and enclosed the vessels, vascular foramina on articular facet and foramina‐covered synovium. Depending on the location, ITCs can be divided into three types: femoral ITC, anterior tibial ITC, and posterior tibial ITC. Clinically, the ITC may facilitate intercondylar transphyseal sarcomatous dissemination without damaging the adjacent physeal cartilage. Compared to bilateral condylar physes, more osteosarcomas transgressed the open growth plates through intercondylar regions in which ITC was located (P = 0.022).

Conclusion

As the “gap” on intact open physis, ITC, which is a new‐identified compound structure in intercondylar regions of immature femur or tibia, may promote intercondylar transphyseal tumor extension. Moreover, the identification and characterization of ITC subvert some traditional comprehensions about physis and may provide novel perspectives for pediatric osteosarcomas.