Hemicortical resection and reconstruction using pasteurised autograft for parosteal osteosarcoma of the distal femur

Does Freehand, Patient-specific Instrumentation or Surgical Navigation Perform Better for Allograft Reconstruction After Tumor Resection? A Preclinical Synthetic Bone Study

BACKGROUND

Joint-sparing resection of periarticular bone tumors can be challenging because of complex geometry. Successful reconstruction of periarticular bone defects after tumor resection is often performed with structural allografts to allow for joint preservation. However, achieving a size-matched allograft to fill the defect can be challenging because allograft sizes vary, they do not always match a patient's anatomy, and cutting the allograft to perfectly fit the defect is demanding.

QUESTIONS/PURPOSES

(1) Is there a difference in mental workload among the freehand, patient-specific instrumentation, and surgical navigation approaches? (2) Is there a difference in conformance (quantitative measure of deviation from the ideal bone graft), elapsed time during reconstruction, and qualitative assessment of goodness-of-fit of the allograft reconstruction among the approaches?

METHODS

Seven surgeons used three modalities in the same order (freehand, patient-specific instrumentation, and surgical navigation) to fashion synthetic bone to reconstruct a standardized bone defect. National Aeronautics and Space Administration (NASA) mental task load index questionnaires and procedure time were captured. Cone-beam CT images of the shaped allografts were used to measure conformance (quantitative measure of deviation from the ideal bone graft) to a computer-generated ideal bone graft model. Six additional (senior) surgeons blinded to modality scored the quality of fit of the allografts into the standardized tumor defect using a 10-point Likert scale. We measured conformance using the root-mean-square metric in mm and used ANOVA for multipaired comparisons (p < 0.05 was significant).

RESULTS

There was no difference in mental NASA total task load scores among the freehand, patient-specific instrumentation, and surgical navigation techniques. We found no difference in conformance root-mean-square values (mean ± SD) between surgical navigation (2 ± 0 mm; mean values have been rounded to whole numbers) and patient-specific instrumentation (2 ± 1 mm), but both showed a small improvement compared with the freehand approach (3 ± 1 mm). For freehand versus surgical navigation, the mean difference was 1 mm (95% confidence interval [CI] 0.5 to 1.1; p = 0.01). For freehand versus patient-specific instrumentation, the mean difference was 1 mm (95% CI -0.1 to 0.9; p = 0.02). For patient-specific instrumentation versus surgical navigation, the mean difference was 0 mm (95% CI -0.5 to 0.2; p = 0.82). In evaluating the goodness of fit of the shaped grafts, we found no clinically important difference between surgical navigation (median [IQR] 7 [6 to 8]) and patient-specific instrumentation (median 6 [5 to 7.8]), although both techniques had higher scores than the freehand technique did (median 3 [2 to 4]). For freehand versus surgical navigation, the difference of medians was 4 (p < 0.001). For freehand versus patient-specific instrumentation, the difference of medians was 3 (p < 0.001). For patient-specific instrumentation versus surgical navigation, the difference of medians was 1 (p = 0.03). The mean ± procedural times for freehand was 16 ± 10 minutes, patient-specific instrumentation was 14 ± 9 minutes, and surgical navigation techniques was 24 ± 8 minutes. We found no differences in procedures times across three shaping modalities (freehand versus patient-specific instrumentation: mean difference 2 minutes [95% CI 0 to 7]; p = 0.92; freehand versus surgical navigation: mean difference 8 minutes [95% CI 0 to 20]; p = 0.23; patient-specific instrumentation versus surgical navigation: mean difference 10 minutes [95% CI 1 to 19]; p = 0.12).

CONCLUSION

Based on surgical simulation to reconstruct a standardized periarticular bone defect after tumor resection, we found a possible small advantage to surgical navigation over patient-specific instrumentation based on qualitative fit, but both techniques provided slightly better conformance of the shaped graft for fit into the standardized post-tumor resection bone defect than the freehand technique did. To determine whether these differences are clinically meaningful requires further study. The surgical navigation system presented here is a product of laboratory research development, and although not ready to be widely deployed for clinical practice, it is currently being used in a research operating room setting for patient care. This new technology is associated with a learning curve, capital costs, and potential risk. The reported preliminary results are based on a preclinical synthetic bone tumor study, which is not as realistic as actual surgical scenarios.

CLINICAL RELEVANCE

Surgical navigation systems are an emerging technology in orthopaedic and reconstruction surgery, and understanding their capabilities and limitations is paramount for clinical practice. Given our preliminary findings in a small cohort study with one scenario of standardized synthetic periarticular bone tumor defects, future investigations should include different surgical scenarios using allograft and cadaveric specimens in a more realistic surgical setting.

Graft Survivals after Reconstruction Using Tumor-Bearing Frozen Bone in the Extremities

Tumor-bearing frozen autografts have been widely used for reconstruction of bone defects caused by tumor resection. However, some patients undergo removal of the grafted bone due to surgical site infection, tumor recurrence, or fractures of the grafted bone. In this retrospective cohort study, predictive factors for graft survival were investigated in 123 patients who underwent reconstructions using a tumor-bearing frozen autograft after bone tumor resection of the extremities. To determine the independent predictors of graft survival, the association between various parameters and graft survival was investigated. The graft survival rates were 83.2% at 5 years and 70.2% at 10 years. Among the 123 frozen autografts, 25 (20.3%) were removed because of complications. In univariate analyses, male sex, BMI of ≥23.6, tibia, and chemotherapy were significantly associated with poor graft survival, whereas the pedicle/hemicortical freezing procedure was significantly associated with better graft survival. Multivariate analysis using the Cox proportional hazards regression model revealed that BMI of ≥23.6 (HR, 3.4; p = 0.005), tibia (HR, 2.3; p = 0.047), and freezing procedure (HR, 0.3; p = 0.016) were independently associated with graft survival. Based on the results, pedicle or hemicortical freezing techniques are recommended in cases where these techniques can be applied.

Oncological and Functional Outcomes after Hemicortical Resection and Biological Reconstruction Using Allograft for Parosteal Osteosarcoma of the Distal Femur

Background

Parosteal osteosarcoma (PAOS) is a surface osteosarcoma. Treatment options include wide excision and endoprosthetic or allograft. However, due to the low local recurrence and metastasis rate, when it appears in the posterior surface of the distal femur, the lesion can be managed with hemicortical wide resection and biological reconstruction with hemicortical allograft. The purpose of this study is to evaluate the oncological and functional outcomes of patients with parosteal osteosarcoma (PAOS) of the posterior cortex of the distal femur who underwent biological reconstruction after hemicortical resection.

Methods

Eleven patients who underwent wide tumor resection and defect reconstruction of the posterior surface of the distal femur using hemicortical allograft were retrospectively studied. Local recurrence, metastasis, complications, and the functional outcome using the Musculoskeletal Tumor Society (MSTS) scoring system were evaluated.

Results

The average postoperative follow-up period was 53.64 months (range, 30 to 84 months). At the latest follow-up, all patients had no evidence of disease without metastases. One patient with local recurrence underwent revision surgery with fibula autograft reconstruction. The mean MSTS score was 93.45 ± 3.56.

Conclusions

Treatment of patients with PAOS of the posterior aspect of the distal femur with hemicortical resection and allograft reconstruction has satisfactory oncological and functional outcome and low complication rates.

Surface bone sarcomas: an update on current clinicopathological diagnosis and treatment

Surface bone sarcomas are rare malignant bone tumours. Osseous and cartilaginous surface bone sarcomas are the most common, with parosteal and periosteal osteosarcomas, periosteal chondrosarcomas and secondary peripheral chondrosarcomas being the most frequent.

Their clinical symptoms are non-specific and include pain for several months, swelling and limited range of motion of the adjacent joints.

Prompt diagnosis is important, as biological behaviour, imaging and histopathologic characteristics, treatment and prognosis differ considerably from their conventional intramedullary counterparts. Moreover, their imaging characteristics are not infrequently non-characteristic and may be misinterpreted as juxtacortical benign lesions leading to incorrect diagnosis and treatment, with life-threatening repercussions. Molecular studies and histopathological sampling are essential for accurate diagnosis.

There are still numerous issues regarding the biology, pathophysiology and treatment options of these entities due to their rarity.

Cite this article: EFORT Open Rev 2021;6:905-917. DOI: 10.1302/2058-5241.6.210064

3D printing guide plate for accurate hemicortical bone tumor resection in metaphysis of distal femoral: a technical note

BACKGROUND

Surgical resection and reconstruction for low-grade bone sarcoma in the metaphysis of the distal femur remain challenging. We hypothesized that 3D printing osteotomy guide plate could assist to accurately resect the tumor lesion and save the joint function.

METHODS

From January 2017 to August 2019, five patients diagnosed with low-grade bone sarcoma in the metaphysis of the distal femur were treated with hemicortical resection using 3D printing guide plate. Autologous bone graft was inactivated in a high-temperature water bath and re-implanted in situ fixed with plate and screw. Patients were followed up from 17 to 33 months. The Musculoskeletal Tumor Society Score was used to evaluate the joint function. X-ray was used to evaluate the bone union.

RESULTS

One patient was paracorticular osteosarcoma, and four cases had highly differentiated chondrosarcoma. All cases were involved in the metaphysis of the distal femur. Patients were followed up from 13 to 33 months, with an average of 23.6 months. There was neither post-operation infection, internal fixation loosening, nor fracture occurrence in any of the patients. The Musculoskeletal Tumor Society Score averaged at 28.1, while the International Society of Limb Salvage imaging score examination averaged 89.8%.

CONCLUSIONS

Here, we demonstrate that the 3D printing osteotomy guide plate-assisted hemicortical bone resection is a beneficial strategy to effectively resect the primary low-grade malignant bone tumors in the metaphysis of the distal femur and retained satisfied joint function.

Computer-assisted surgical planning of complex bone tumor resections improves negative margin outcomes in a sawbones model

PURPOSE

Several technologies have been implemented in orthopedic surgery to improve surgical outcomes, usually focusing on more accurate execution of a surgical plan, but the development of the plan itself is also of great importance. The purpose of this study is to examine whether the use of preoperative computer planning platforms can improve the surgical plan?

METHODS

Eight surgeons created a preoperative surgical plan to resect a distal femur parosteal osteosarcoma in two settings: (1) Using a 2-D and 3-D CT scan only (current standard); and (2) using a computer-assisted planning platform. The plans were thereafter virtually executed using a novel surgical navigation system and a Sawbones model. This simulated model was derived from, and identical to, an actual patient scenario. The outcomes of interest were the number of positive margin cuts, and the volume of the resected specimen.

RESULTS

Using the surgical plan developed with computer assistance, there were 4 positive margin cuts made by 2 surgeons. In comparison, using standard planning, there were 14 positive margin cuts made by all 8 surgeons (p = 0.02). The resection volume was larger in the computer-assisted plans (96 ± 10 mm³) than in the standard plans (88 ± 7 mm³) (p = 0.055).

CONCLUSIONS

Computer-assisted planning significantly decreased the risk of a positive margin resection in this Sawbones tumor model used to simulate resection of a primary bone sarcoma. This proof of concept study highlights the importance of advanced surgical planning and sets the ground for developing beneficial surgical planning systems.

Cone-Beam Computed Tomography-Guided Navigation in Complex Osteotomies Improves Accuracy at All Competence Levels: A Study Assessing Accuracy and Reproducibility of Joint-Sparing Bone Cuts

BACKGROUND

The objective of this study was to assess the accuracy and reproducibility of a novel cone-beam computed tomography (CBCT)-guided navigation system designed for osteotomies with joint-sparing bone cuts.

METHODS

Eighteen surgeons participated in this study. First, 3 expert tumor surgeons resected bone tumors in 3 Sawbones tumor models identical to actual patient scenarios. They first performed these osteotomies without navigation and then performed them using a navigation system and 3-dimensional (3D) planning tools based on CBCT imaging. The 2 sets of measurements were compared using image-based measurements from post-resection CBCT. Next, 15 residents, fellows, and orthopaedic staff surgeons were instructed on the use of the system, and their navigated resections were compared with navigated resections performed by the 3 expert tumor surgeons.

RESULTS

One hundred and twenty-six navigated cuts done by the orthopaedic oncologists were compared with 126 non-navigated cuts by the same surgeons. The cuts violated the tumor in 22% (6) of the 27 non-navigated resections compared with none of the 27 navigated resections. The navigated cuts were significantly more accurate in terms of entry point, pitch, and roll (p < 0.001). The variation among the 3 surgeons when they used navigation was <0.6 mm for the entry cut and, on average, 1.5° for pitch and roll. All 18 surgeons then completed a total of 144 navigated cuts. The level of experience did not result in a significant difference among groups with regard to cut accuracy. Two cuts went into the tumor. The mean distance from the planned bone cuts to the actual entry points into bone was 1.5 mm (standard deviation [SD] = 1.4 mm) for all users. The mean difference in pitch and roll between the planned and actual cuts was 3.5° (SD = 2.8°) and 3.7° (SD = 3.2°) for all users.

CONCLUSIONS

Even in expert hands, navigated cuts were significantly more accurate than non-navigated cuts. When the osteotomies were aided by navigation, their accuracy did not differ according to the level of professional experience. CBCT-based metrics enable intraoperative assessments of cut accuracy and reconstruction planning.

CLINICAL RELEVANCE

CBCT-guided navigated osteotomies can improve accuracy regardless of surgeon experience and decrease the variability among different surgeons.

Non-vascularised fibula grafts for reconstruction of segmental and hemicortical bone defects following meta- /diaphyseal tumour resection at the extremities

Background

The reconstruction of meta−/diaphyseal bone defects following bone tumour resection is challenging, and biological treatment options should be applied whenever possible, especially in benign lesions and early stage sarcomas. We aimed to evaluate the results of segmental (SR) and hemicortical reconstructions (HR) at the extremities using non-vascularised fibula grafts.

Methods

We retrospectively enrolled 36 patients who were treated with non-vascularised fibula reconstructions (15 SR, 21 HR) after bone tumour resection (15 malignant, 21 benign). All cases were evaluated regarding consolidation, hypertrophy at the graft-host junctions, and complications; moreover, the functional and oncological results were assessed. The mean follow-up was 8.3 years (2.1–26.6 years).

Results

Primary union was achieved in 94% (SR 87%, HR 100%) of patients, and 85% (SR 81%, HR 88%) showed hypertrophy at the graft-host junction. The overall complication rate was 36% with 4 patients (11%) developing local recurrence. There was a significant correlation between the development of mechanical complications (fracture, delayed-/non-union) and a defect size of ≥12 cm (p = 0.013), segmental defects (p = 0.013) and additional required treatment (p = 0.008). The functional outcome was highly satisfactory (mean MSTS score 86%).

Conclusions

Due to encouraging results and advantages (such as their remodelling capacity at the donor site), non-vascularised fibula reconstructions should be considered a valuable alternative treatment option for patients with hemicortical defects or segmental reconstructions of less than 12 cm in which no additional neo-/adjuvant treatment is necessary.

Impacts of Tumor Location, Nature and Bone Destruction of Extremity Osteosarcoma on Selection of Limb Salvage Operative Procedure

OBJECTIVE

To study the impacts of tumor location, nature and extent of bone destruction on selection of operative protocol for extremity osteosarcoma (OS).

METHODS

The medical records of 201 patients with extremity OS treated in our institute from December 1999 to June 2014 were retrospectively reviewed. Ninety eligible patients (56 males and 34 females) of average age 20 ± 11 years (range, 4-40 years) were enrolled. Tumor locations were categorized as diaphyseal (4; diaphysis group) or juxta-articular (86); the latter being subclassified as with (51, type III, epiphysis group) or without invasion beyond the epiphyseal line or plate (35, type I and II, metaphysis group) according to MRI images. Tumor nature (osteogenic, 51; osteolytic, 39) was determined radiologically. Extent of bone destruction was quantitated according to Mirel's scoring system to obtain an "invasion score". Regular postoperative follow-up included physical examination and imaging evaluation.

RESULTS

Fifty-four patients underwent biological reconstruction and 36 mechanical reconstruction. The mean follow-up duration was 51 months (range, 6-176 months, including four deaths within 12 months). Biological reconstruction was performed more frequently in the diaphysis and metaphysis groups (31/39, 79.5%) than mechanical reconstruction (8/39, 20.5%, P < 0.05). Biological reconstruction and articular preservation were associated with more satisfactory limb function (MSTS scores: 25.0 ± 3.3 and 25.1 ± 3.6) than mechanical reconstruction and articular resection (MSTS scores: 23.4 ± 3.7 and 23.1 ± 3.4, P < 0.05). Reconstruction methods and articular preservation had no relationship with overall or tumor-free survival (P > 0.05). Osteolytic lesions were associated with more extensive bone destruction than osteogenic lesions according to invasion scores (P < 0.05). Following biological reconstruction, high invasion scores (>8) had a 13.5-fold risk of fracture compared with low scores (≤8) (P < 0.05). Twenty-one subjects had recurrences, 30 metastases and 26 died. Postoperative complications included infection (6), fracture (10), and prosthesis loosening (4). Kaplan-Meier analysis indicated 5- and 10-year survival rates of 68.9% and 62.8%, respectively, and 5- and 10-year tumor-free survival rates of 66.7% and 57.8%, respectively.

CONCLUSION

Selection of limb salvage operative protocol for extremity OS should rely on tumor location, nature and extent of bone destruction. Regardless of tumor site, mechanical reconstruction is indicated for tumors with high invasion scores (>8), whereas biological reconstruction is preferred for those with low invasion scores (≤8). Tumors sparing the epiphyseal line or plate are ideal candidates for articular preservation.

The prognostic and therapeutic factors which influence the oncological outcome of parosteal osteosarcoma

The aim of this study was to evaluate the prognostic and therapeutic factors which influence the oncological outcome of parosteal osteosarcoma.

A total of 80 patients with a primary parosteal osteosarcoma were included in this retrospective study. There were 51 females and 29 males with a mean age of 29.9 years (11 to 78).

The mean follow-up was 11.2 years (1 to 40). Overall survival was 91.8% at five years and 87.8% at ten years. Local recurrence occurred in 14 (17.5%) patients and was associated with intralesional surgery and a large volume of tumour. On histological examination, 80% of the local recurrences were dedifferentiated high-grade tumours. A total of 12 (14.8%) patients developed pulmonary metastases, of whom half had either a dedifferentiated tumour or a local recurrence. Female gender and young age were good prognostic factors. Local recurrence was a poor prognostic factor for survival. Medullary involvement or the use of chemotherapy had no impact on survival.

The main goal in treating a parosteal osteosarcoma must be to achieve a wide surgical margin, as inadequate margins are associated with local recurrence. Local recurrence has a significant negative effect on survival, as 80% of the local recurrences are high-grade dedifferentiated tumours, and half of these patients develop metastases.

The role of chemotherapy in the treatment of parosteal osteosarcoma is not as obvious as it is in the treatment of conventional osteosarcoma. The mainstay of treatment is wide local excision.

Cite this article: Bone Joint J 2015;97-B:1698–1703.

The long-term outcomes following the use of inactivated autograft in the treatment of primary malignant musculoskeletal tumor

Background

Biological reconstruction surgery is a tough but alluring option for treating primary malignant musculoskeletal tumors. In this article, we evaluate the clinical outcomes of primary malignant musculoskeletal tumors treated with inactivated autograft using alcohol.

Method

In this article, we include 58 patients who had primary malignant bone tumors treated with wide resection and recycling autograft reconstruction using alcohol between January 2003 and January 2013. The outcomes were measured by recurrence, functional status, and complications. Functional status was assessed according to the Musculoskeletal Tumor Society Score (MSTSS). The Kaplan-Meier survival curve was used to evaluate the survival rate of the patient.

Result

The most common tumor was osteosarcoma (31 cases) followed by chondrosarcoma (10 cases). The tibia was the most frequently involved skeletal site (27 cases) followed by femur (26 cases). The median follow-up period was 54 months, ranging from 18 to 96 months. In 58 patients, 12 were with local recurrence (20.7 %), 16 with lung metastasis (27.6 %), and 13 with complications (22.4 %). The main complication was infection (8 cases). The autografts survived in 49 patients (84.5 %). The mean MSTSS score was 78.5 %, ranging from 47 to 98 %.

Conclusion

Recycling autograft reconstruction using alcohol had favorable clinical outcomes to some degree; however, the recurrence and complication rates seem to be high. Thus, we should apply this method with caution and choose the patients with strict surgical indication.

Limb salvage: When, where, and how?

From an era where amputation was the only option to the current day function preserving resections and complex reconstructions has been a major advance in the treatment of musculoskeletal sarcomas. The objectives of extremity reconstruction after oncologic resection include providing skeletal stability where necessary, adequate wound coverage to allow early subsequent adjuvant therapy, optimising the aesthetic outcome and preservation of functional capability with early return to function. This article highlights the concepts of surgical margins in oncology, discusses the principles governing safe surgical resection in these tumors and summarises the current modalities and recent developments relevant to reconstruction after limb salvage. The rationale of choice of a particular resection modality and the unique challenges of reconstruction in skeletally immature individuals are also discussed. Striking the right balance between adequate resection, while yet retaining or reconstructing tissue for acceptable function and cosmesis is a difficult task. Complications are not uncommon and patients and their families need to be counseled regarding the potential setbacks that may occur in the course of their eventual road to recovery, Limb salvage entails a well orchestrated effort involving various specialties and better outcomes are likely to be achieved with centralization of expertise at regional centers.

Surface osteosarcomas: Diagnosis, treatment and outcome

Surface osteosarcomas are a rare form of osteosarcomas accounting for around 3-6% of all osteosarcomas. Three major groups of surface osteosarcomas are parosteal, periosteal and the high grade surface osteosarcomas. Of these, the parosteal osteosarcoma is the most common. Parosteal and periosteal osteosarcomas are distinct clinical entities and it is important to identify the clinicoradiological differences between the two types. Surface osteosarcomas occur at a later age as compared to conventional osteosarcomas. The classical site is the lower end of the femur followed by the upper end of the tibia and upper end of humerus, in that order. The periosteal variant affects the tibia more commonly than the parosteal variety. Neo-adjuvant chemotherapy is the standard of care for high grade surface osteosarcomas. Parosteal osteosarcomas, being low grade lesions, can be treated by upfront wide excision without adjuvant systemic therapy. Controversy prevails over the need for chemotherapy in periosteal osteosarcomas, which are intermediate grade lesions.