Computerized surgical navigation resection of pelvic region simulated bone tumors using skin fiducial marker registration: an in vitro cadaveric study

INTRODUCTION

Computerized surgical navigation system guidance can improve bone tumor surgical resection accuracy. This study compared the 10-mm planned resection margin agreement between simulated pelvic-region bone tumors (SPBT) resected using either skin fiducial markers or Kirschner (K)-wires inserted directly into osseous landmarks with navigational system registration under direct observation. We hypothesized that skin fiducial markers would display similar resection margin accuracy.

METHODS

Six cadaveric pelvises had one SPBT implanted into each supra-acetabular region. At the left hemi-pelvis, the skin fiducial marker group had guidance from markers placed over the pubic tubercle, the anterior superior iliac spine, the central and more posterior iliac crest, and the greater trochanter (5 markers). At the right hemi-pelvis, the K-wire group had guidance from 1.4-mm-diameter wires inserted into the pubic tubercle, and 3 inserted along the iliac crest (4 K-wires). The senior author, a fellowship-trained surgeon performed "en bloc" SPBT resections. The primary investigator, blinded to group assignment, measured actual resection margins.

RESULTS

Twenty of 22 resection margins (91%) in the skin fiducial marker group were within the Bland-Altman plot 95% confidence interval for actual-planned margin mean difference (mean = -0.23 mm; 95% confidence intervals = 2.8 mm, - 3.3 mm). Twenty-one of 22 resection margins (95%) in the K-wire group were within the 95% confidence interval of actual-planned margin mean difference (mean = 0.26 mm; 95% confidence intervals = 1.7 mm, - 1.1 mm).

CONCLUSION

Pelvic bone tumor resection with navigational guidance from skin fiducial markers placed over osseous landmarks provided similar accuracy to K-wires inserted into osseous landmarks. Further in vitro studies with different SPBT dimensions/locations and clinical studies will better delineate use efficacy.

Revolutionizing bone tumor management: cutting-edge breakthroughs in limb-saving treatments

Limb salvage surgery has revolutionized the approach to bone tumors in orthopedic oncology, steering away from historical amputations toward preserving limb function and enhancing patient quality of life. This transformative shift underscores the delicate balance between tumor eradication and optimal postoperative function. Primary and metastatic bone tumors present challenges in early detection, differentiation between benign and malignant tumors, preservation of function, and the risk of local recurrence. Conventional methods, including surgery, radiation therapy, chemotherapy, and targeted therapies, have evolved with a heightened focus on personalized medicine. A groundbreaking development in limb salvage surgery is the advent of 3D-printed patient-specific implants, which significantly enhance anatomical precision, stability, and fixation. These implants reduce soft tissue disruption and the associated risks, fostering improved osseointegration and correction of deformities for a more natural and functional postoperative outcome. Biological and molecular research has reshaped the understanding of bone tumors, guiding surgical interventions with advancements such as genomic profiling, targeted intraoperative imaging, precision targeting of molecular pathways, and immunotherapy tailored to individual tumor characteristics. In the realm of imaging technologies, MRI, CT scans, and intraoperative navigation systems have redefined preoperative planning, minimizing collateral damage and optimizing outcomes through accurate resections. Postoperative rehabilitation plays a crucial role in restoring function and improving the quality of life. Emphasizing early mobilization, effective pain management, and a multidisciplinary approach, rehabilitation addresses the physical, psychological, and social aspects of recovery. Looking ahead, future developments may encompass advanced biomaterials, smart implants, AI algorithms, robotics, and regenerative medicine. Challenges lie in standardization, cost-effectiveness, accessibility, long-term outcome assessment, mental health support, and fostering global collaboration. As research progresses, limb salvage surgery emerges not just as a preservation tool but as a transformative approach, restoring functionality, resilience, and hope in the recovery journey. This review summarizes the recent advances in limb salvage therapy for bone tumors over the past decade.

3D Specimen Scanning and Mapping in Musculoskeletal Oncology: A Feasibility Study

BACKGROUND

Surgical resection is the primary treatment for bone and soft tissue tumors. Negative margin status is a key factor in prognosis. Given the three-dimensional (3D) anatomic complexity of musculoskeletal tumor specimens, communication of margin results between surgeons and pathologists is challenging. We sought to perform ex vivo 3D scanning of musculoskeletal oncology specimens to enhance communication between surgeons and pathologists.

METHODS

Immediately after surgical resection, 3D scanning of the fresh specimen is performed prior to frozen section analysis. During pathologic grossing, whether frozen or permanent, margin sampling sites are annotated on the virtual 3D model using computer-aided design (CAD) software.

RESULTS

3D scanning was performed in seven cases (six soft tissue, one bone), with specimen mapping on six cases. Intraoperative 3D scanning and mapping was performed in one case in which the location of margin sampling was shown virtually in real-time to the operating surgeon to help achieve a negative margin. In six cases, the 3D model was used to communicate final permanent section analysis. Soft tissue, cartilage, and bone (including lytic lesions within bone) showed acceptable resolution.

CONCLUSIONS

Virtual 3D scanning and specimen mapping is feasible and may allow for enhanced documentation and communication. This protocol provides useful information for anatomically complex musculoskeletal tumor specimens. Future studies will evaluate the effect of the protocol on positive margin rates, likelihood that a re-resection contains additional malignancy, and exploration of targeted adjuvant radiation protocols using a patient-specific 3D specimen map.

Fracture risk after intralesional curettage of atypical cartilaginous tumors

INTRODUCTION

The need for curettage of atypical cartilaginous tumors (ACT) is under debate. Curretage results in defects that weaken the bone potentially leading to fractures. The purpose of this study was to retrospectively determine postoperative fracture risk after curettage of chondroid tumors, including patient-specific characteristics that could influence fracture risk.

METHODS

A total of 297 adult patients who underwent curettage of an ACT followed by phenolisation and augmentation were retrospectively evaluated. Explanatory variables were, sex, age, tumor size, location, augmentation type, and plate fixation. The presence of a postoperative fracture was radiologically diagnosed. Included patients had at least 90 days of follow-up.

RESULTS

A total of 183 females (62%) were included and 114 males (38%), with an overall median follow-up of 3.2 years (IQR 1.6-5.2). Mean diameter of the lesions was 4.5 (SD 2.8) cm. Patients received augmentation with allograft bone (n = 259, 87%), PMMA (n = 11, 3.7%), or did not receive augmentation (n = 27, 9.1%). Overall fracture risk was 6%. Male sex (p = 0.021) and lesion size larger than 3.8 cm (p < 0.010) were risk factors for postoperative fracture.

INTERPRETATION

Curettage of ACT results in an overall fracture risk of 6%, which is increased for males with larger lesions.

Titanium vs. carbon fiber-reinforced intramedullary nailing for humeral bone tumors

BACKGROUND

Multiple techniques have been described to treat humeral diaphyseal bone tumors requiring curettage or excision. Recent studies have suggested that carbon fiber-reinforced polyetheretherketone (CFR-PEEK) intramedullary nails (IMNs) may be preferable to titanium IMNs for patients with musculoskeletal tumors due to CFR-PEEK's high tensile strength, radiolucency, a modulus of elasticity closer to native bone, and improved postoperative surveillance/radiation dosing. In this study, we describe the rate of fixation failure for both CFR-PEEK and titanium humeral IMNs when used for humeral diaphyseal bone tumors requiring curettage or excision.

METHODS

This was a single-institution retrospective cohort study including 81 patients (27 CFR-PEEK and 54 titanium) treated for a humeral diaphyseal bone tumor using an IMN ± methylmethacrylate between January 2017 and December 2022. Primary outcome was revision surgery due to soft tissue complications, nonunions, structural complications such as periprosthetic fracture or IMN breakage, periprosthetic infection, tumor progression, and implant failure due to rejection or fatigue.

RESULTS

No failures were observed in either patients treated with titanium nails or patients treated with CFR-PEEK not requiring curettage. Fixation failure due to implant failure was observed in 2 cases-at 214 days and 469 days after surgery-where CFR-PEEK IMN was used for stabilization after a wide segmental resection for oncologic control with a cement spacer reconstruction. In both cases, the resection was larger than 6 cm, the remaining distal humerus was less than 5 cm, and failures occurred at the interface of the residual bone and spacer. Both patients were revised using a titanium distal posterolateral humeral plate fixed with screws and cables without any subsequent complications. One additional CFR-PEEK IMN required revision surgery after 744 days due to progression of the tumor and subsequent nonunion. One revision surgery was observed after 63 days for the titanium IMN because of nonunion and tumor progression.

CONCLUSIONS

Humeral diaphyseal bone tumors requiring large segmental resection with small residual bone and a large cement spacer may fail via tension due to bending forces at the distal portion. In this clinical scenario, the use of larger-diameter CFR-PEEK IMNs may be indicated when available. In the interim, use of intercalary allografts instead of cement spacers, additional fixation with a titanium plate distally, or the use of a titanium nail when using a cement spacer may be considered.

Statin-related muscle complications masquerading as soft tissue sarcomas

Musculoskeletal injuries are a known side effect of long-term statin use. These injuries include sudden, atraumatic muscle rupture which can cause extremity hematomas that motivate patients to seek evaluation and physicians to send referrals for oncologic workup. We discuss two cases where malignancy was suspected rather than statin-induced muscle injury. Using these cases as examples, we discuss subtleties between the two diagnoses so that muscle rupture may be considered prior to subspecialist referral. This paper aims to serve as a reminder and guide for physicians who encounter long-term statin users with nonspecific, improving musculoskeletal symptoms and hemorrhagic MRI findings that lack nodular or mass-like enhancements. While referral to orthopedic oncology is always encouraged in cases of uncertainty, it may not always be necessary.

Aneurysmal bone cyst of the clavicle: A case report

INTRODUCTION

An aneurysmal bone cyst (ABC) is a locally aggressive primary bone neoplasm. ABC of the clavicle is rare with only a few reported cases in the literature.

PRESENTATION OF CASE

We report the case of a 10-year-old boy who presented with an ABC at the right acromial end of the clavicle. The patient underwent intralesional curettage and allogenic bone grafting. Moreover, the patient's arm was placed in a sling for 2 weeks postoperatively. The patient had a satisfactory outcome after 11 years, with excellent Toronto Extremity Salvage, Quick-Dash, and Musculoskeletal Tumor Society scores.

DISCUSSION

Clavicular ABCs are uncommon. Early diagnosis helps to prevent pathological fractures. Adjuvant therapies might help decrease recurrence.

CONCLUSION

ABC should be considered an important differential diagnosis for clavicular swelling and masses. The best results can be achieved using curettage and void-filled bone grafts.

LEVEL OF EVIDENCE: 4

Tumor size and surgical margins are important prognostic factors of synovial sarcoma - A retrospective study

Background

Synovial Sarcoma (SS) is a rare soft tissue sarcoma. Mean time to get a SS diagnosis from the onset of symptoms is 10 years, furthermore, SS is associated with late metastasis. Surgery is the main treatment option, whose quality deeply affects SS outcomes, and it can be associated to preoperative or post-operative radiotherapy. Chemotherapy is considered very effective in Children, while in adults its efficacy is still under debate. The aim of this study was to investigate the oncologic results in SS treatment and to identify the risk factors for local and systemic control of the disease.

Methods

From 1994 to 2018, 211 patients affected by SS were treated in 3 Referral Centres of Orthopaedic Oncology. One hundred seventy-seven patients were included in the study, the median follow-up length was 96 months (5-374).

Results

Overall Survival on the Kaplan Meier Analyses was 80%, 70% and 56% at 5, 10 and 20 years. In multivariate analyses, OS correlated with tumour size and negative surgical margins. Chemotherapy use wasn't associated with better survival although patients who underwent CT had bigger and more aggressive tumours.

Conclusions

Our findings suggests that surgery with negative margins is the most important factor in Synovial Sarcoma. Adjuvant treatments as chemotherapy and radiation therapy didn't change the disease's course.

Carbon-fiber-reinforced polyetheretherketone orthopedic implants in musculoskeletal and spinal tumors: imaging and clinical features

Carbon-fiber-reinforced polyetheretherketone (CFR-PEEK) orthopedic implants are gaining popularity in oncologic applications as they offer many potential advantages over traditional metallic implants. From an imaging perspective, this instrumentation allows for improved evaluation of adjacent anatomic structures during radiography, computed tomography (CT), and magnetic resonance imaging (MRI). This results in improved postoperative surveillance imaging quality as well as easier visualization of anatomy for potential image-guided percutaneous interventions (e.g., pain palliation injections, or ablative procedures for local disease control). CFR-PEEK devices are also advantageous in radiation oncology treatment due to their decreased imaging artifact during treatment planning imaging and decreased dose perturbation during radiotherapy delivery. As manufacturing processes for CFR-PEEK materials continue to evolve and improve, potential orthopedic applications in the spine and appendicular skeleton increase. An understanding of the unique properties of CFR-PEEK devices and their impact on imaging is valuable to radiologists delivering care to orthopedic oncology patients in both the diagnostic and interventional settings. This multidisciplinary review aims to provide a comprehensive insight into the radiologic, surgical, and radiation oncology impact of these innovative devices.

Automated elaborate resection planning for bone tumor surgery

PURPOSE

Planning for bone tumor resection surgery is a technically demanding and time-consuming task, reliant on manual positioning of planar cuts in a virtual space. More elaborate cutting approaches may be possible through the use of surgical robots or patient-specific instruments; however, methods for preparing such a resection plan must be developed.

METHODS

This work describes an automated approach for generating conformal bone tumor resection plans, where the resection geometry is defined by the convex hull of the tumor, and a focal point. The resection geometry is optimized using particle swarm, where the volume of healthy bone collaterally resected with the tumor is minimized. The approach was compared to manually prepared planar resection plans from an experienced surgeon for 20 tumor cases.

RESULTS

It was found that algorithm-generated hull-type resections greatly reduced the volume of collaterally resected healthy bone. The hull-type resections resulted in statistically significant improvements compared to the manual approach (paired t test, p < 0.001).

CONCLUSIONS

The described approach has potential to improve patient outcomes by reducing the volume of healthy bone collaterally resected with the tumor and preserving nearby critical anatomy.

Management of Proximal Humeral Oncologic Lesions

The proximal humerus is a common location for primary tumors, benign lesions, and metastatic disease. Advances in neoadjuvant and adjuvant therapy have allowed for limb-salvage surgery in most of the cases. There are numerous of options for surgical management of proximal humerus lesions and the decision to pursue one over another depends on factors such as age, comorbidities, pathology, location within the proximal humerus, planned resection margins/size of defect, and bone quality. Long-term outcomes for these techniques tend to be retrospective comparative studies, with recent studies highlighting the improved outcomes of reverse total shoulders.

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.

Occupational injuries and burn out among orthopedic oncology surgeons

BACKGROUND

Orthopedic oncology surgeons commonly engage in prolonged and complex surgical procedures. These types of surgeries increase the risk of physical and psychological stressors, which may in turn make these physicians prone to work-related occupational injuries.

AIM

The aim of this study was to explore in orthopedic oncologists, the prevalence of work-related physical injuries and psychological disturbances.

METHODS

A modified version of the physical discomfort survey was developed to assess occupational injuries among orthopedic oncology surgeon members of the Musculoskeletal Tumor Society, the Canadian Orthopedic Oncology Society and European Musculoskeletal Oncology Societies. The survey was sent by email, and it explored musculoskeletal complaints, psychological disturbances, treatment required for these complaints and the requirement of time off work.

RESULTS

A total of 67 surgeon responses were collected. A high number of orthopedic oncologists (84%) reported an occupational injury. Low back pain (39%) was the most prevalent musculoskeletal condition, followed by lumbar disk herniation (16%), shoulder tendinitis (15%) and lateral epicondylitis (13%). Of the cohort, 46% required surgery and 31% required time off work due to their injury. Thirty-three respondents reported a psychological disorder. Burnout (27%), anxiety (20%) and insomnia (20%) were the most commonly reported. Time required off work due to injury was associated with old age and years in practice.

CONCLUSION

Orthopedic oncology surgeons report a high prevalence of work-related disorders. Lower back related injury and burnout were the most reported disorders. Improving operative room ergonomics and prevention of stress related to the work environment should be areas to explore in upcoming research.

In situ cryoablation of sacral Giant Cell Tumor using three-dimensional (3D) model: A case report

Three-dimensional planning of in-situ (trans-sacral) image guided cryoablation provides a method to treat sacral GCTs that accommodates the intricacies of the pelvis offering a safer, more efficacious alternative. Here we report on IM a 23-year-old female with a sacral GCT. She presented to Tel Aviv Medical Center with ongoing pain as well as neurological symptoms. For six years, the patient was in-and-out of the hospital for Denosumab treatment and recurrent infections. Eventually, further treatment became necessary, and she was treated with image guided cryoablation. By six months follow-up, the patient was mobile and pain-free.

Artificial intelligence applied to musculoskeletal oncology: a systematic review

Developments in artificial intelligence have the potential to improve the care of patients with musculoskeletal tumors. We performed a systematic review of the published scientific literature to identify the current state of the art of artificial intelligence applied to musculoskeletal oncology, including both primary and metastatic tumors, and across the radiology, nuclear medicine, pathology, clinical research, and molecular biology literature. Through this search, we identified 252 primary research articles, of which 58 used deep learning and 194 used other machine learning techniques. Articles involving deep learning have mostly involved bone scintigraphy, histopathology, and radiologic imaging. Articles involving other machine learning techniques have mostly involved transcriptomic analyses, radiomics, and clinical outcome prediction models using medical records. These articles predominantly present proof-of-concept work, other than the automated bone scan index for bone metastasis quantification, which has translated to clinical workflows in some regions. We systematically review and discuss this literature, highlight opportunities for multidisciplinary collaboration, and identify potentially clinically useful topics with a relative paucity of research attention. Musculoskeletal oncology is an inherently multidisciplinary field, and future research will need to integrate and synthesize noisy siloed data from across clinical, imaging, and molecular datasets. Building the data infrastructure for collaboration will help to accelerate progress towards making artificial intelligence truly useful in musculoskeletal oncology.

Automated resection planning for bone tumor surgery

Planning for bone tumor resection surgery is a technically demanding and time-consuming task, reliant on manual positioning of cutting planes (CPs). This work describes an automated approach for generating bone tumor resection plans, where the volume of healthy bone collaterally resected with the tumor is minimized through optimized placement of CPs. Particle swarm optimization calculates the optimal position and orientation of the CPs by introducing a single new CP to an existing resection, then optimizing all CPs to find the global minima. The bone bounded by all CPs is collaterally resected with the tumor. The approach was compared to manual resection plans from an experienced surgeon for 20 tumor cases. It was found that a greater number of CPs reduce the collaterally resected healthy bone, with diminishing returns on this improvement after five CPs. The algorithm-generated resection plan with equivalent number of CPs resulted in a statistically significant improvement over manual plans (paired t-test, p < 0.001). The described approach has potential to improve patient outcomes by reducing loss of healthy bone in tumor surgery while offering a surgeon multiple resection plan options.

Pelvic Ewing sarcoma: Should all patients receive pre-operative radiotherapy, or should it be delivered selectively?

BACKGROUND

Locally recurrent disease following surgical resection of Ewing sarcoma (ES) confers a poor prognosis. Limited evidence is available evaluating non-selective use of pre-operative radiotherapy (RT) for patients with pelvic ES and its effect on local control and survival.

PATIENTS AND METHODS

49 consecutive patients with pelvic ES were identified retrospectively from a prospectively collated database. Patients either received non-selective pre-operative RT and surgery (n = 27), or selective post-operative RT (n = 22) (surgery alone (n = 11) or surgery and post-operative RT (n = 11)).

RESULTS

Patients who had non-selective pre-operative radiotherapy appeared to have a higher LRFS, 88.0% compared to 66.5% in the selective RT group (p = 0.096, Kaplan Meier; p = 0.028, Chi-squared). Administration of non-selective, pre-operative RT to all patients with pelvic ES elevates the LFRS to that of the good responder group (≥90% tumour necrosis and margins, p = 0.880). There was no difference in metastasis-free survival, 60.0% and 54.5% (p = 0.728) and overall survival (OS), 57.7% and 63.6% (p = 0.893). The majority of pre-operative RT patients had both good necrosis (≥90%) (p = 0.003) and widely excised tumours, 81.5% vs 59.1% (p = 0.080). Tumour volume ≥250 ml was associated with worse LRFS (p = 0.045) and post-operative complications (p = 0.017). There may be improved LRFS (p = 0.057) with pre-operative proton-beam RT compared to surgery and selective post-operative RT.

CONCLUSION

Pre-operative photon or proton-beam RT to all pelvic ES may improve LRFS compared to the selective delivery of post-operative RT. Radiotherapy delivered to all patients results in a greater percentage of highly necrotic tumours at surgical excision, enabling a greater proportion of patients with wide resection margins.

Prophylactic Antibiotic Regimens In Tumor Surgery (PARITY): a multi-center randomized controlled study comparing alternative antibiotic regimens in patients undergoing tumor resections with endoprosthetic replacements-a statistical analysis plan

BACKGROUND

Limb salvage with endoprosthetic reconstruction is the current standard practice for the surgical management of lower extremity bone tumors in skeletally mature patients and typically includes tumor resection followed by the functional limb reconstruction with modular metallic and polyethylene endoprosthetic implants. However, owing to the complexity and length of these procedures, as well as the immunocompromised nature of patients treated with chemotherapy, the risk of surgical site infection (SSI) is high. The primary research objective of the Prophylactic Antibiotic Regimens In Tumor Surgery (PARITY) trial is to assess whether a 5-day regimen of post-operative antibiotics decreases the risk of SSI at 1 year post-operatively compared to a 1-day regimen. This article describes the statistical analysis plan for the PARITY trial.

METHODS/DESIGN

The PARITY trial is an ongoing multi-center, blinded parallel two-arm randomized controlled trial (RCT) of 600 participants who have been diagnosed with a primary bone tumor, a soft tissue sarcoma that has invaded the bone or oligometastatic bone disease of the femur or tibia that requires surgical resection and endoprosthetic reconstruction. This article describes the overall analysis principles, including how participants will be included in each analysis, the presentation of results, adjustments for covariates, the primary and secondary outcomes, and their respective analyses. Additionally, we will present the planned sensitivity and sub-group analyses.

DISCUSSION

Our prior work has demonstrated (1) high rates of SSI after the treatment of lower extremity tumors by surgical excision and endoprosthetic reconstruction, (2) highly varied opinion and practice among orthopedic oncologists with respect to prophylactic antibiotic regimens, (3) an absence of applicable RCT evidence, (4) extensive support from international investigators to participate in a RCT, and (5) the feasibility of conducting a definitive RCT to evaluate a 5-day regimen of post-operative antibiotics in comparison with a 1-day regimen.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01479283 . Registered on 24 November 2011.

Recruitment patterns in a large international randomized controlled trial of perioperative care in cancer patients

INTRODUCTION

The Prophylactic Antibiotic Regimens in Tumor Surgery (PARITY) randomized controlled trial (RCT) was the first study to prospectively enroll and randomize orthopedic oncology patients in multiple centers internationally. The objective of this study was to describe recruitment patterns, to examine the differences in enrollment across different PARITY sites, and to identify variables associated with differing levels of recruitment.

METHODS

Data from this study was obtained from the PARITY trial Methods Center and records of correspondence between the Methods Center and recruiting sites. We performed descriptive statistics to report the recruitment patterns over time. We compared recruitment, time to set up, and time to enroll the first patient between North American and international sites, private and public healthcare models, and the presence or absence of research personnel. Two-tailed non-paired t tests were performed to test average monthly recruitment rates between groups.

RESULTS

A total of 602 patients from 36 North American and 12 international sites were recruited from 2013 to 2019. North American sites were able to become fully enrollment-ready at an average of 19.5 months and international sites at an average of 27 months. Once enrolling, international sites were able to enroll 0.59 patients per/month whereas North American sites averaged a monthly recruitment rate of 0.2 patients/month once enrolling. Sites with research personnel reached enrollment-ready status at an average of 19.3 months and sites without research support at an average of 30.3 months. Once enrolling, the recruitment rate was 0.28 patients/month and 0.2 patients per month for sites with and without research support, respectively. Publicly funded sites had a monthly enrollment of 0.4 patients/month whereas privately funded sites had a monthly enrollment rate of 0.17 patients/month.

CONCLUSIONS

As a collaborative group, the PARITY investigators increased the pace of recruitment throughout the trial, likely by increasing the number of active sites. The longer time to start-up at international sites may be due to the complex governing regulations of pharmaceutical trials. Nevertheless, international sites should be considered essential as they recruited significantly more patients per month once active. The absence of research support personnel may lead to delays in the time to start-up. The results of the current study will provide guidance for choosing which sites to recruit for participation in future collaborative clinical trials in orthopedic oncology and other surgical specialties.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01479283 . Prospectively registered on November 24, 2011.

Two Cases of Polyethylene Granuloma After Distal Femoral Endoprosthesis With All-Polyethylene Tibia

Limited literature exists on complications specific to the all-polyethylene tibial component in distal femoral replacement (DFR). Unlike in primary arthroplasty with polyethylene components, polyethylene granuloma has not been reported in DFR with an all-polyethylene tibia. Here, we report 2 cases of polyethylene granuloma in patients with primary bone sarcoma who underwent DFR with an all-polyethylene tibia. Radiologically, evidence of intraosseous granuloma formation and periprosthetic osteolysis was observed at the anterior tibial metaphysis. Both patients underwent an operative debridement of polyethylene granuloma and necrotic tissues, followed by a revision to a long-stem, cemented metal-backed tibia with impacted allograft to fill the defect. Polyethylene granuloma should be considered a differential diagnosis in the presence of a periprosthetic lytic lesion after DFR with an all-polyethylene tibial component.

NUT midline carcinoma in a young pregnant female: a case report

INTRODUCTION

The NUT midline carcinoma is a rare tumor mostly reported in the midline of upper aerodigestive tract and mediastinum. Children as well as adolescents are affected without a gender distribution. A standard treatment is not established. So far, there exists no reported case of a pregnant female suffering from NUT midline carcinoma with musculoskeletal manifestation.

CASE PRESENTATION

A 34-year-old woman was referred to our outpatient clinic by the general practitioner during her 31st week of pregnancy suffering from shoulder pain and dyspnea. So far, dyspnea was interpreted as a typical pregnancy-related symptom. However, a chest X-ray showed a tumor mass in the right lung in close relation to the scapula. Further examinations found metastases in different areas of the body. No pregnancy-related complications were detected by obstetric examination. After an interdisciplinary perinatal case discussion, cesarean section was directly followed by an open biopsy of the right side scapula tumor lesion. A NUT midline carcinoma was diagnosed by immunohistochemistry. Due to disseminated tumor disease in multiple non-resectable locations, a palliative systemical chemotherapy was started by the oncological outpatient clinic.

CONCLUSION

This report presents the case of the very rare NUT midline carcinoma under pregnancy which made interdisciplinary case discussions indispensable for therapy planning.

Gait analysis: Comparative evaluation of conventional total knee replacement and modular distal femoral megaprosthesis

BACKGROUND

Gait alterations have been studied with computer-assisted gait analysis after megaprosthetic replacement for tumors around the knee. It has never been proven that megaprostheses affects gait more than total knee arthroplasty (TKA); this study aims to compare via gait analysis patients who underwent megaprosthesis with patients with TKA.

METHODS

We analyzed 26 patients with a megaprosthetic replacement of the distal femur and 21 patients with a standard TKA. For each subject computerized gait analysis was performed. Range of motion (ROM) of the knee was recorded, Quality of Life and functional evaluation in the oncologic group were assessed with the Musculoskeletal Tumor Society (MSTS) questionnaire, while Short Form-36 (SF-36) scores were calculated for both groups.

RESULTS

All patients walked slower than healthy people (P < 0.05). Gait analysis showed a lower cadence than in the healthy population but no significant difference between the two groups. A longer swing and a shorter stance phase were detected in the megaprosthetic sample. The osteoarthritis group showed greater flexion during the phase of loading response, even if this was lower than the contralateral limb or healthy population. There was a statically significant difference between the healthy limb and the operated one in both groups regarding ROM, but no significant difference was registered between the two implants. MSTS score and most of SF-36 parameters showed no significant differences compared with literature data.

CONCLUSIONS

Gait analysis shows little discrepancy between the two groups; gait pattern abnormalities do not affect patients with a megaprosthetic replacement more significantly than patients undergoing TKA.

Computer navigation assisted tumor surgery for internal hemipelvectomy - Early experience

Internal hemipelvectomy is a surgically challenging entity, owing, among other reasons, to a complex anatomy. The apprehension of an inadequate margin or injury to critical structures adds to the complexity of these major surgical procedures. Computer assisted tumor surgery (CATS) has been increasingly used to improve outcomes of internal hemipelvectomy over the last decade. We analyzed the surgical and postoperative details of first four patients undergoing internal hemipelvectomy with CATS assistance at our institute, the first ever report in an Indian setting. The patients were analyzed for blood loss (mean 1300 ml), operative time (mean 306 min) and hospital stay (mean 7 days). The histopathological margins were free of disease in all the patients, even as the average closest bony margin was 0.9 cm. Sparing of sacral nerve root was made possible by the close yet free margins in two patients. In this retrospective analysis of a small series of patients with computer navigation assisted internal hemipelvectomy, we found this technique to be feasible and effective in achieving the oncological aim of negative margins with preservation of critical structures.

What factors influence patient experience in orthopedic oncology office visits?

BACKGROUND

Patient satisfaction and reported outcomes are becoming increasingly important in determining the efficacy of clinical care. To date no study has evaluated the patient experience in the orthopedic oncology outpatient setting to determine which factors of the encounter are priorities to the patient.

AIM

To evaluate what factors impact patient experience and report satisfaction in an outpatient orthopedic oncology clinic.

METHODS

Press Ganey^® patient surveys from a single outpatient orthopedic oncology clinic at a tertiary care setting were prospectively collected per routine medical care. All orthopedic oncology patients who were seen in clinic and received electronic survey were included. All survey responses were submitted within one month of clinic appointment. IRB approval was obtained to retrospectively collect survey responses from 2015 to 2016. Basic demographic data along with survey category responses were collected and statistically analyzed.

RESULTS

One hundred sixty-two patient surveys were collected. Average patient age was 54.4 years (SD = 16.2 years) and were comprised of 51.2% female and 48.4% male. 64.2% of patients were from in-state. Out of state residents were more likely to recommend both the practice and attending physician. The likelihood to recommend attending physician was positively associated with MD friendliness/courtesy (OR = 14.4, 95%CI: 2.5-84.3), MD confidence (OR = 48.2, 95%CI: 6.2-376.5), MD instructions follow-up care (OR = 2.5, 95%CI: 0.4-17.4), and sensitivity to needs (OR = 16.1, 95%CI: 1-262.5). Clinic operations performed well in the categories of courtesy of staff (76%) and cleanliness (75%) and less well in ease of getting on the phone (49%), information about delays (36%), and wait time (37%).

CONCLUSION

Orthopedic specialties can utilize information from this study to improve care from the patient perspective. Future studies may be directed at how to improve these areas of care which are most valued by the patient.

Primary arthroplasty in healed osteoarticular allograft in patients with history of primary femoral bone tumors

BACKGROUND

Roughly 25-35% of patients who are treated with osteoarticular allograft for primary bone sarcomas or aggressive benign bone tumors require surgery in the long-term due to degenerative changes of the articular surface of the allograft. There are three established methods of reconstruction for this complication; a total hip arthroplasty (THA) or total knee arthroplasty (TKA) in the retained osteoarticular allograft, a proximal or distal endoprosthesis after removal of the allograft, and an allograft-prosthesis composite (APC). The aims of this study are 1) to determine the rate of complication and failure of THA/TKA in healed femoral allograft; 2) to compare the methods of revision for allograft degeneration; and 3) to compare the use of arthroplasty in healed allograft to that of arthroplasty in native bone.

METHODS

We included all patients with primary bone sarcomas and locally aggressive primary benign bone tumors treated between 1984 and 2014 with an osteoarticular allograft followed by any subsequent arthroplasty technique as described above. Complications and reasons for failure are described following the classification of Henderson et al. Failure was defined as any complication leading to removal of the initial treatment construct. Failure rates of these groups were compared to primary arthroplasty in a live host bone (Control Group).

RESULTS

Complications happened in 25 (61.0%) of the patients with a THA/TKA in the retained allograft, of these, 24 (58.5%) experienced failure, the most common being structural failure/type III (14, 58.3%). Thirteen patients (81.3%) with an endoprosthesis after removal of the allograft experienced complications, all of whom failed. The most common failure modes were aseptic loosening/type II (4, 30.8%) and infection/type IV (5, 38.5%). Complications in patients with an APC were experienced by 12 (85.7%) patients, 11 (78.6%) of whom failed. The most common failure mode was infection/type IV (4, 36.4%). Significantly (p < 0.001) fewer failures were observed in the control group compared to patients with an arthroplasty in a healed allograft.

CONCLUSIONS

We found no significant difference in the outcome of treating patients with allograft and subsequent degenerative bone disease with a THA/TKA in a retained allograft, an endoprosthesis after removal of the allograft, or a primary APC, although infection is a significantly greater cause of failure in the latter two. Primary arthroplasty in healed allografts is a less extensive surgery than removing the allograft and shows comparable complication and failure rates.

LEVEL OF EVIDENCE

Level III, Therapeutic Study.

Allograft selection for distal femur through cutting contour registration

Allograft reconstruction is an acceptable procedure for the recovery of normal anatomy after the bone tumor resection. During the past few years, several automated methods have been proposed to select the best anatomically matching allograft from the virtual donor bone bank. The surface-based automated method uses the contralateral healthy bone to obtain the normal surface shape of the diseased bone, which could achieve good matching of the defect and the selected allograft. However, the surface-based method focuses on the matching of the whole bone so that the matching of the contact surface between the allograft and the recipient bone may not be optimal. To deal with the above problem, we propose a cutting contour based method for the allograft selection. Cutting contour from the recipient bone could reflect the structural information of the defect and is seldom influenced by tumor. Thus the cutting contour can be used as the matching template to find the optimal alignment of the recipient bone and the allograft. The proposed method is validated using the data of distal femurs where bone transplantation is commonly performed. Experimental results show that the proposed method generally outperforms the surface-based method within modest extra time. Overall, our contour-based method is an effective complementary technique for allograft selection in the virtual bone bank.

Techniques in surgical navigation of extremity tumors: state of the art

Image-guided surgical navigation allows the orthopedic oncologist to perform adequate tumor resection based on fused images (CT, MRI, PET). Although surgical navigation was first performed in spine and pelvis, recent reports have described the use of this technique in bone tumors located in the extremities. In long bones, this technique has moved from localization or percutaneous resection of benign tumors to complex bone tumor resections and guided reconstructions (allograft or endoprostheses). In recent years, the reported series have increased from small numbers (5 to 16 patients) to larger ones (up to 130 patients). The purpose of this paper is to review recent reports regarding surgical navigation in the extremities, describing the results obtained with different kind of reconstructions when navigation is used and how the previously described problems were solved.

Use of Computer Navigation in Orthopedic Oncology

The use of computer navigation was first described in the surgical resection of pelvic tumors in 2004. It was developed to improve surgical accuracy with the goal of achieving clear resection margins and better oncologic results. During the past few years, there has been tremendous advancement of computer-assisted tumor surgery (CATS) in the field of orthopedic oncology. Currently, CATS with image fusion offers preoperative three-dimensional surgical planning and allows surgeons to reproduce the intended bone resections in musculoskeletal tumors. The technique is reported to be useful in technically demanding resections, such as in pelvic and sacral tumors; joint-preserving intercalated and multiplanar tumor resection; and complex reconstruction with custom computer-aided design prostheses or allografts. This article provides an up-to-date review of the recent developments and key features in CATS, its current status in clinical practice, and future directions in its development.