Pelvic resections

Geriatric nutritional risk index as a predictor for surgical site infection in malignant musculoskeletal tumours of the trunk

BACKGROUND AND OBJECTIVE

Surgical site infection (SSI) is common in surgery for malignant musculoskeletal tumours, specifically those arising from the trunk. In this study, we investigated the risk factors for SSI after resection of musculoskeletal tumours of the trunk.

METHODS

This retrospective observational study included 125 patients (72 males, 53 females) with musculoskeletal tumours of the trunk in our hospital from 1 April 2008 to 31 August 2023. The incidence of SSI and its risk factors were investigated.

RESULTS

SSI was observed in 26% (32/125), and the median time to SSI was 22 days. On multivariate analysis, the following were identified as risk factors for SSI: tumours arising caudal to Jacoby's line (hazard ratio [HR] 4.04; P = .0107), soft tissue reconstruction (HR 3.43; P = .0131), and low Geriatric Nutritional Risk Index (GNRI) (HR 0.96; P = .0304). Patients were classified into two risk categories based on GNRI scores: the risk group (GNRI ≤98) and no risk group (>98). The risk group showed a significantly lower overall noninfection survival rate (P = .023).

CONCLUSION

Tumours arising caudal to Jacoby line, soft tissue reconstruction, and lower GNRI were risk factors for SSI. Preoperative and postoperative nutritional interventions should be considered to improve GNRI.

How Does Customized Cutting Guide Design Affect Accuracy and Ergonomics in Pelvic Tumor Resection? A Study in Cadavers

BACKGROUND

Customized cutting guides are technical aids that make primary pelvic bone tumor resection safer and more reliable. Although the effectiveness of such devices appears to be widely accepted, their conception and design remain varied. Two main designs have been reported: the heavier block-type customized cutting guides and the lighter patch-type customized cutting guides. As recent tools, there must be more evidence regarding the impact of design on their accuracy and ergonomics. Thus, an evaluation of their respective performances appears warranted.

QUESTIONS/PURPOSES

In a cadaver model, we assessed whether (1) a thinner, patch-type customized cutting guide design results in resections that are closer to the planned resections than the heavier block-type customized cutting guides, and (2) the patch-type customized cutting guide design is more ergonomic than the block-type customized cutting guide with improved usability in surgery (in terms of bulkiness, ease of placement, primary and secondary stability, and stability during cutting).

METHODS

We conducted an experimental study involving five fresh whole-body anatomic specimens (three women and two men with a median age of 79 years and median weight of 66 kg) by simulating six virtual tumors in three areas according to the Enneking classification (Zones I: iliac wing, II: periacetabular area, and I and IV: sacroiliac joint area). We compared the impact of the customized cutting guide's design on performance in terms of the resection margin accuracy using CT scan analysis (deviation from the planned margin at the closest point and the maximum deviation from the planned margin) and the intraoperative ergonomic score under conditions simulating those of an oncologic resection of a bone tumor (with a range of 0 to 100, with 100 being best).

RESULTS

The patch customized cutting guides performed slightly better than the block customized cutting guides regarding deviation from the planned margin at the closest point, with median values of 1 mm versus 2 mm (difference of medians 1 mm; p = 0.02) and maximum deviation from the planned margin of 3 versus 4 mm (difference of medians 1 mm; p = 0.002). In addition, the patch design was perceived to be slightly more ergonomic than the block design, with a 92% median score versus 84% for the block design (difference of medians 8%; p = 0.03).

CONCLUSION

We observed an equivalence in performance regarding accuracy and ergonomics, with slight advantages for patch customized cutting guides, especially in complex zones (Zone I and IV). Owing to a small cohort in a cadaver study, these results need independent replication.

CLINICAL RELEVANCE

The patch-type customized cutting guide with thinner contact spots to the bone in specific areas and less soft tissue dissection might offer an advantage over a larger block design for achieving negative oncologic bony margins, but it does not address issues of soft tissue margins.

Complications and Functional Outcome Differences in Carbon Ion Radiotherapy and Surgery for Malignant Bone Tumors of the Pelvis: A Multicenter, Cohort Study

BACKGROUND

Carbon ion radiotherapy (CIRT) is an evolving treatment option for malignant pelvic tumors in patients with poor surgical indications. However, the difference in complications and functional outcomes between CIRT and surgery is poorly understood. This study compares the complications and functional outcomes of CIRT and surgery to facilitate treatment selection.

METHODS

A total of 28 patients who underwent CIRT for pelvic bone tumors while theoretically meeting the surgical resection criteria were included. Sixty-nine patients who underwent surgery for pelvic bone tumors were included as controls. Major complication rates and functional outcomes (ambulatory, pain, urination, constipation) were evaluated and compared at several time points (pretreatment, discharge, and final follow-up) between the groups.

RESULTS

Early (within 90 days) major complications were not observed in the CIRT group but occurred in 30% of the surgery group, which was statistically significant (P < 0.001). In contrast, late (after 90 days) major complications occurred more often in the CIRT group than in the surgery group (18% and 4%, respectively; P = 0.042). From pretreatment until discharge, all functional outcomes in the surgery group deteriorated (P < 0.001 for all) but did not change in the CIRT group (P = 0.77-1.00). At the final follow-up, all functional outcomes showed no significant intergroup difference (P = 0.28-0.92) due to the recovery trend in the surgery group and the deterioration trend in the CIRT group.

CONCLUSIONS

Compared with surgery, CIRT may have favorable safety and stable functional outcomes in the short-term but more late complications. Mid-term functional outcomes were similar between the groups.

The outcome of type 1 pelvic resection and reconstruction with pedicle screw-rod system without bone grafting in malignant pelvic tumour: A case series and short term review

INTRODUCTION

There is no consensus regarding the reconstruction method for type 1 resections around the pelvis. Various methods are currently used, such as resection without reconstruction, bone graft (autologous, recycled, allograft) with simple fixation, and pedicle screw-rod fixation with or without bone grafting. We aim to study the outcome of pedicle screw-rod reconstruction without bone grafting in type 1 pelvic resections involving sacroiliac joint to show that pedicle screw-rod construct alone is stable and has low risk of failure.

MATERIAL AND METHODS

This is a retrospective review of eight patients who underwent type 1 resection of malignant pelvic tumours and reconstruction with a pedicle screw-rod system between 2011 and 2018. All patients who underwent type 1 resection and reconstruction with pedicle screw without bone grafting were included into this study. We reported their clinical (complication and radiological outcome), oncological (local recurrence and metastasis), and functional outcome based on Musculoskeletal Tumour Society Score (MSTS) and The Toronto Extremity Salvage Score (TESS) at their last follow-up.

RESULTS

Eight patients were recruited into the study. The mean follow-up period was 58.5 months (range: 40 - 121 months). There were three postoperative complications in three different patients: superficial infection, surgical hernia with ipsilateral femoral avascular necrosis (AVN), and femoral nerve injury. At the end of the study period, one patient passed away due to disease progression, one patient was alive with disease, and the rest were disease-free. Mean MSTS score during last follow-up was 77.1% (range: 66.7% - 93.3%), while mean TESS score was 75.6% range (63.3% - 80.2%). There were no cases of implant failure.

CONCLUSION

Type 1 pelvic reconstruction with a pedicle screw-rod system is stable without a concurrent biological reconstruction, and it is feasible, with few complications, and an excellent functional outcome.

Preoperative arterial embolization and wound complications after resection of malignant bone tumor in the pelvis: a nationwide database study

BACKGROUND

Massive intraoperative blood loss is common in pelvic malignant bone tumor surgery, and preoperative arterial embolization may be used in selected cases. Preoperative arterial embolization reportedly increases wound complications in pelvic fracture surgery, but little evidence is available regarding pelvic bone tumor surgery.

METHODS

Using a Japanese nationwide database (Diagnosis Procedure Combination database), we searched for patients who underwent pelvic malignant bone tumor surgery between July 2010 and March 2018. The primary endpoint was wound complications, defined as any wound requiring re-operation, negative pressure wound therapy or both. Univariate analyses (the chi-squared test for categorical variables, the unpaired t-test for continuous variables) and multivariate logistic regression analyses were performed to examine the association between preoperative arterial embolization and wound complications.

RESULTS

Among the 266 eligible patients, 43 (16%, 43/266) underwent embolization and 69 (26%, 69/266) developed wound complications. In the univariate analyses, preoperative arterial embolization (P < 0.001), duration of anesthesia (P < 0.001), the volume of blood transfusion (P < 0.001) and duration of indwelling drain tube (P < 0.001) were associated with wound complications. In the multivariate logistic regression analysis, preoperative arterial embolization was significantly associated with wound complications (odds ratio, 3.92; 95% confidence interval, 1.80-8.56; P = 0.001).

CONCLUSIONS

Preoperative arterial embolization may be associated with increased wound complications after pelvic malignant tumor surgery.

Custom-made 3D-Printed Prosthesis in Periacetabular Resections Through a Novel Ileo-adductor Approach

Resection of sarcomas around the acetabulum presents major challenges. The resulting bone effect can be reconstructed with personalized custom-made prostheses. Patient-specific instruments (PSIs) have been demonstrated to be of added value for bone-cutting accuracy, and they may improve pelvic surgery. The authors describe a novel ileo-adductor approach for pelvic tumor surgery and report the preliminary results of 5 reconstructions using custom 3D-printed prostheses associated with PSI surgical guides. This combined technique allows an optimal restoration of the anatomy with reduced surgical time and reduced postoperative complications such as infections and wound healing problems. [Orthopedics. 2022;45(2):e110-e114.].

Gigantic secondary pelvic chondrosarcomas treated with pelvic resection type I and III: A case report

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Proper selection of patients, preoperative planning and wide surgical margins with reconstruction provides good local control and clinical outcomes following pelvic resection.

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Patient with huge tumor need large amount of blood transfusion and postoperative intensive care due to longer surgery time.

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The surgical site infection is common complication after pelvic resection and can be managed with debridement and antibiotic therapy.

Introduction

Patients with osteochondromatosis have a higher risk of malignant transformation into secondary chondrosarcoma. Chondrosarcoma at the pelvic region tends to present late and therefore pose a significant challenge for orthopedic surgeons because of the large tumor size, local extension, and complex anatomy with proximity to major neurovascular structure, intestinal and urinary tract.

Presentation of case

A 44-year-old male presented the chief complaint of 15 years growing lumps on his left buttock and right groin, presenting with pain. Plain radiography revealed popcorn calcification at the left iliac wing and right superior pubic rami. Multiple exostoses were also visible. MRI showed a larger tumor diameter at the left iliac wing by 33 cm and right pubic rami by 13 cm. The histopathological result from the biopsy suggested low-grade chondrosarcoma.

Result

The patient underwent pelvic resection type I and III in two-stage surgery. About one month after the first surgery, there was a postoperative infection. Debridement and antibiotic therapy resulted in a desirable functional outcome with an MSTS score 27 and no local recurrence sign during a one-year follow-up.

Discussion

Low-grade chondrosarcomas are not sensitive to radiation and chemotherapy; wide surgical resection is the mainstay of treatment. Chondrosarcoma at the iliac wing can be treated by pelvic resection type I, and further reconstruction needed to prevent pelvic tilting. Chondrosarcoma at pubic rami can be treated by pelvic resection type III.

Conclusion

Proper patient selections, preoperative planning, and wide surgical margins with reconstruction provide desirable local control and clinical outcomes following pelvic resection.

Complications following Iliac Wing Fibrosarcoma

The aim of this case report is to underline surgical strategies for complications in a case of a young man with fibrosarcoma of the bone treated with pelvic resection followed by reconstruction with massive bone allograft. A type I pelvic resection was performed as a radical resection of tumor followed by a biological reconstruction of iliac wing using frozen allograft. The iliac allograft was fixed in place using 4 screws. The immediate postoperative period was complicated with local sepsis of reconstructed site treated with pediculate omentoplasty. After 1 year from surgery, the X-ray exam showed an integrated allograft. After 20 years from the first surgery, the patient presented with the left hip pain of 3-month duration with mechanical pattern. The X-ray and CT exam showed the left hip arthritis and no signs of recurrence. A total hip arthroplasty with dual mobility cup and uncemented stem was performed. Despite the immediate postoperative local infection, the allograft was left in place and integrated after all. Omentoplasty could be a very useful technique in eradicating local infection, due to the immunogenic properties of the omentum. The allograft is still strong enough to give support for a hip arthroplasty at 20 years after implantation.

The pararectus approach-a versatile option in pelvic musculoskeletal tumor surgery

Background

Pelvic tumors are usually resected through the utilitarian pelvic incision, an extended ilioinguinal/iliofemoral approach. The pararectus approach, an intrapelvic anatomical approach with extraperitoneal access to the pelvis, has been established previously for the treatment of pelvic and acetabular fractures. However, it has not been used to address pelvic tumors. The study aimed at investigating the feasibility of this approach for pelvic tumor surgery and the possibilities of combining this approach with standard approaches to the hip joint.

Methods

Thirteen patients that underwent pelvic tumor resections were retrospectively reviewed. Tumor resections were performed through the pararectus (n = 10) or extended pararectus approach (n = 3). In six of those cases, the pararectus approach was combined with extrapelvic approaches including the modified Gibson (n = 4), the Kocher-Langenbeck (n = 1), and the trochanteric flip approach (n = 1). The mean follow-up was 32.6 ± 9.1 months.

Results

In all cases, the tumor resections were carried out according to the preoperative plan. In seven of 13 cases, wide resections were performed; six of 13 cases were planned close resections. Four cases of major complications were observed (vascular injury, deep infection, iliac vein thrombosis, total hip arthroplasty dislocation). Minor complications were observed in two cases. One tumor recurred locally. At the final follow-up, 10 patients were alive, eight of those without evidence of disease.

Conclusion

The study demonstrated the suitability of the pararectus approach for pelvic tumor resections. The possibility to combine the approach with standard approaches to the hip joint allowed for single-stage reconstructions of the pelvis and the hip joint without sacrificing surgical margins and function. The pararectus approach is a versatile option adding to the established approaches for musculoskeletal tumor surgery of the pelvis.

In vitro experimental and numerical study on biomechanics and stability of a novel adjustable hemipelvic prosthesis

Hemipelvic prostheses are used to reconstruct the damaged pelvis due to bone tumors and traumas. However, biomechanical properties of the reconstructed pelvis remain unclear, causing difficulties to implant development and prediction of surgical outcome. In this study, a novel adjustable hemipelvic prosthesis for the Type 1-3 pelvis resection was used to reconstruct the intact pelvic ring. Two types of Pedicle Screw Rod Systems were proposed to improve the stability of fixation between the prosthesis and the bone. Finite Element models of the reconstructed pelvis were built to analyze the performance of the prosthesis and PSRS. Moreover, an in vitro experimental study was performed to measure the deformation of the human reconstructed pelvis. Numerical results agree well with the experimental data. It was found that displacements and stresses bilaterally transferred more evenly in the reconstructed pelvis enhanced by bilateral Pedicle Screw Rod System. The load-transfer function of the pelvis under double-leg standing stance could be recovered. The bilateral pedicle system has better biomechanical performance than the unilateral pedicle system.

Adult Primary Bone Sarcoma and Time to Treatment Initiation: An Analysis of the National Cancer Database

Objective

The time to treatment interval (TTI), defined as the period from diagnosis to first definitive treatment, has very limited descriptions toward understanding delays in primary bone sarcoma (PBS) care. Our primary goal was to determine the national standard for time to treatment initiation (TTI) in PBS in adults and to identify characteristics associated with TTI variability.

Methods

An analysis of the National Cancer Database identified 15,083 adult patients with PBS diagnosed from 2004 to 2013. Kruskal–Wallis analysis identified differences between covariates regarding TTI and regression modeling identified covariates that independently influenced TTI.

Results

The median TTI was 22 days. Approximately 60% of patients were definitively treated in the same center where the index diagnosis was made. Increased TTI was correlated with a transition in care institution (incidence rate ratio (IRR) = 1.89; P < 0.001), being uninsured (IRR = 1.36; P < 0.001), primary tumor site in the pelvis (IRR = 1.26; P < 0.001), Medicaid insurance status (IRR = 1.22; P < 0.001), care at an academic center (IRR = 1.14; P < 0.001), non-white race (IRR = 1.12; P=0.002), and Medicare insurance status (IRR = 1.08; P=0.017). Decreased TTI was correlated with a diagnosis of chondrosarcoma (IRR = 0.85; P < 0.001), having surgery as the index treatment (IRR = 0.88; P < 0.001), a primary tumor site of the lower (IRR = 0.91; P=0.001) or upper extremity (IRR = 0.92; P=0.023), and stage II or stage III disease (IRR = 0.91; P=0.010).

Conclusions

TTI is associated with tumor, treatment, and socioeconomic and healthcare system characteristics. Transitions in care between institutions are responsible for the greatest increase in TTI. As TTI is more commonly used as a quality metric, physicians need to be aware of the causes for prolonged TTI, as we work to improve national delays in diagnosis and treatment initiation.

Conventional Primary Central Chondrosarcoma of the Pelvis: Prognostic Factors and Outcome of Surgical Treatment in 162 Patients

BACKGROUND

Studies focusing on the oncological outcome after treatment of conventional primary central chondrosarcoma of pelvic bone are lacking. We conducted this retrospective study at 5 referral centers to gain insight in the outcome of treatment for this tumor type and to identify risk factors for impaired oncological outcome.

METHODS

One hundred and sixty-two consecutive patients (118 male patients [73%]) who underwent resection of a conventional primary central chondrosarcoma of pelvic bone from 1985 to 2013 were evaluated. The median age was 51 years (range, 15 to 78 years). The median follow-up was 12.6 years (95% confidence interval [CI], 8.4 to 16.9 years). There were 30 grade-I lesions (19%), 93 grade-II lesions (57%), and 39 grade-III lesions (24%).

RESULTS

Sixty-two patients (38%) experienced local recurrence: 9 grade-I lesions (30%), 31 grade-II lesions (33%), and 22 grade-III lesions (56%). Forty-eight patients (30%) developed metastases. The risk of disease-related death was 3% for grade-I tumors (1 of 30; this patient had a grade-II recurrence and died of metastases), 33% (31 of 93) for grade-II tumors, and 54% (21 of 39) for grade-III tumors. Identified risk factors for impaired disease-specific survival were tumor grade (grade II: hazard ratio [HR], 20.18; p = 0.003; and grade III: HR, 58.94; p < 0.001), resection margins (marginal: HR, 3.21; p = 0.001; and intralesional: HR, 3.56; p < 0.001), and maximal tumor size (HR, 1.08 per cm; p = 0.026). Deep infection (19% [n = 31]) was the predominant complication.

CONCLUSIONS

This study offers a standard for survival rates for conventional primary central chondrosarcoma of the pelvis. The survival for grade-I tumors was excellent. Wide resection margins were associated with a significant survival advantage for higher-grade tumors. Because of the inability to reliably distinguish low-grade and high-grade tumors preoperatively, we conclude that any central pelvic chondrosarcoma should be treated with aggressive primary resection with the aim of obtaining wide resection margins. There may be aggressive biologic features in some tumors for which a surgical procedure alone may not be adequate to improve outcomes.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Oncological and surgical outcome after treatment of pelvic sarcomas

Background and objectives

Treatment of pelvic tumors remains challenging due to complex anatomy, poor oncological outcome and high complication rates. We sought to investigate the long-term oncological and surgical outcome of these patients.

Methods

Between 1980 and 2012, 147 patients underwent surgical treatment for pelvic sarcoma. Histological diagnosis was Chondrosarcoma in 54, Ewing’s Sarcoma/PNET in 37, Osterosarcoma in 32 and others in 24 patients. Statistical analysis for the evaluation of oncological and surgical outcome was performed by applying Cox proportional hazards regression and Fine-Gray regression models for competing risk (CR) endpoints.

Results

The estimated overall survival (OS) to death was 80%, 45% and 37% at 1, 5 and 10 years, respectively. Univariate analyses revealed a statistically significant unadjusted influence of age age (p = 0.038; HR = 1.01), margin (p = 0.043; HR = 0.51) and grade (p = 0.001; HR = 2.27) on OS. Considering the multivariable model, grade (p = 0.005; HR = 3.04) and tumor volume (p = 0.014; HR = 1.18) presented themselves as independent prognostic factors on OS. CR analysis showed a cumulative incidence for major complication of 31% at 5 years. Endoprosthetic reconstruction had a higher risk for experiencing a major complication (p<0.0001) and infection (p = 0.001).

Conclusions

Pelvic resections are still associated with a high incidence of complications. Patients with pelvic reconstruction and high volume tumors are especially at risk. Consequently, a cautious decision-making process is necessary when indicating pelvic reconstruction, although a restrictive approach to pelvic reconstruction is not necessarily reasonable when the other option is major amputation.

Surgical management of pelvic bone sarcoma with internal hemipelvectomy: Oncologic and Functional outcomes

INTRODUCTION

The management of pelvic sarcoma is challenging and goals of surgery are adequate oncologic local control, maintenance of optimum function with good quality of life.

METHODS

We have evaluated the results of internal hemipelvecotmy including age, type of resection, reconstruction, radiotherapy or chemotherapy. From 2010 to 2016, 23 patients with pelvic bone tumors (13 with Ewing's sarcoma, 9 with Osteosarcoma, 1 with chondrosarcoma) were treated by surgical resection.

RESULTS

The mean follow-up was 18 months (0.5-5) years. In 12 patients reconstruction was performed and 11 were without reconstruction. A total of 3 patients (13%) had an infection develop at a mean follow up of 1 month. Surgical debridement's and antibiotics in three patients led to complete recovery. One patient had sciatic nerve injury.One patient had injury to femoral vein; was treated with femoral vein reconstruction. Two patients (9%) developed a local recurrence and were treated with best supportive treatment. Distal pulmonary metastases were seen in four patients and treated with supportive treatment. Five-year disease-specific survival rates of all patients were 83%. The mean functional MSTS score was 18(14-24).

CONCLUSIONS

Proper selection of patients, preopertive planning and wide surgical margins with reconstruction provides good functional outcomes following internal hemipelvectomy. The surgical site infection and flap necrosis tend to be minor complication and can be managed leading to optimal outcomes and justifies the need for this complex surgery. The oncological and functional outcome after internal hemipelvectomy suggests that it's an effective method for treatment of patients with pelvic sarcomas.

Design and biomechanical study of a novel adjustable hemipelvic prosthesis

A pelvic endoprosthesis is commonly used in orthopedic surgeries to reconstruct the pelvis after internal hemipelvectomy. This study presents the detailed design of a novel type I+II+III adjustable hemipelvic prosthesis based on the geometrical features of massive human pelvises. Finite element analysis is conducted to estimate the biomechanical performance of the newly designed adjustable hemipelvic prosthesis. Detailed numerical models of the natural and reconstructed pelvises including related soft tissues are developed. Hip contact forces during normal walking, which is one of the most frequent dynamic activities in daily living, are imposed on the pelvis. Results show that the peak stress observed in the reconstructed pelvis model is still within a low and elastic range below the yielding strength of the cortical bone and Ti6Al4V. No significant difference of the stress transferring route, displacement distributions and principal stress vectors is observed between the reconstructed and natural pelvises. The results indicate that the load transferring function of the partially resected pelvis is able to be reliably recovered by the adjustable hemipelvic prosthesis. The principal stress vectors in both pelvis models predict that bone absorption may not apparently occur in the long run. Long-term biomechanical performance of this newly designed prosthesis may be stability.

Potential accuracy of navigated K-wire guided supra-acetabular osteotomies in orthopedic surgery: a CT fluoroscopy cadaver study

BACKGROUND

The aim of this study was to evaluate the accuracy of supra-acetabular pelvic tumor resections in human, full-body cadavers and under realistic operation room conditions with the help of a navigation system and K-wires as guidance for the oscillating saw.

METHODS

Seven hemipelvises from fresh, human, male, full-body cadavers were used. A preoperative and a postoperative CT was performed. Under control of the navigation system K-wires were inserted and served as guidance for the oscillating saw to reduce the error by vibration and jerking movements. The accuracy of the computer aided resections was compared with the accuracy of freehand resections in customized 3D printed pelvises with geometries identical to the cadavers used.

RESULTS

The mean deviation of the navigated osteotomies was 1.9 mm (standard deviation 1.0 mm) significantly (P < 0.001) lower than the mean deviation of freehand osteotomies at 9.2 mm (standard deviation 3.7 mm).

CONCLUSION

Navigated K-wires for supra-acetabular osteotomies allow significantly higher accuracy than freehand procedures under simulated operation room conditions. Copyright © 2016 John Wiley & Sons, Ltd.

Image-guided installation of 3D-printed patient-specific implant and its application in pelvic tumor resection and reconstruction surgery

Nowadays, the diagnosis and treatment of pelvic sarcoma pose a major surgical challenge for reconstruction in orthopedics. With the development of manufacturing technology, the metal 3D-printed customized implants have brought revolution for the limb-salvage resection and reconstruction surgery. However, the tumor resection is not without risk and the precise implant placement is very difficult due to the anatomic intricacies of the pelvis. In this study, a surgical navigation system including the implant calibration algorithm has been developed, so that the surgical instruments and the 3D-printed customized implant can be tracked and rendered on the computer screen in real time, minimizing the risks and improving the precision of the surgery. Both the phantom experiment and the pilot clinical case study presented the feasibility of our computer-aided surgical navigation system. According to the accuracy evaluation experiment, the precision of customized implant installation can be improved three to five times (TRE: 0.75±0.18 mm) compared with the non-navigated implant installation after the guided osteotomy (TRE: 3.13±1.28 mm), which means it is sufficient to meet the clinical requirements of the pelvic reconstruction. However, more clinical trials will be conducted in the future work for the validation of the reliability and efficiency of our navigation system.

The effect of an external hip joint stabiliser on gait function after surgery for tumours located around the circumference of the pelvis: analysis of seven cases of internal hemipelvectomy or proximal femur resection

PURPOSE

Limb-sparing resection of malignant pelvic tumours provides the opportunity for patients to obtain better post-operative mobility. However, because few studies have examined in detail the gait function of patients following pelvic tumour resection, the factors affecting gait performance remain to be clarified. Here, with the laboratory-based computer-assisted gait analysis, we evaluated these patients' gait objectively and the impact of a hip-stabilising supporter on gait improvement was simultaneously examined.

METHODS

Three-dimensional gait analysis was performed to obtain cross-sectional data for seven post-operative patients (mean age, 42.7 years; range, 20-61 years) who underwent various types of resection, including P1/4 internal hemipelvectomy (IH), P1/2/3 IH, and proximal femur resection with prosthetic reconstruction. To assess the immediate effects of a hip joint stabiliser, we instructed subjects to walk at their self-selected preferred speed and compared gait parameters with and without use of the hip stabiliser.

RESULTS

At baseline, the average walking speed was 0.75 m/s (95% CI 0.53-0.97). As shown by the intra-subject comparison, the hip stabiliser increased walking speed in all but one subject, increasing both temporal and spatial parameters. Ground reaction force of operated limbs increased for some subjects, while step length increased on at least one side in all subjects.

CONCLUSIONS

Improvement in the gait parameters is indicative of better control provided by the external hip stabiliser over the affected limb. Moreover, our findings show the potential of a biomechanical approach to improve gait function following pelvic tumour resection.

The effect of surgery with radiation on pelvic Ewing sarcoma survival

BACKGROUND

Pelvic Ewing sarcoma (ES) has poorer outcomes than extremity-based lesions and the method of local control is controversial.

METHODS

A retrospective review was performed of 40 primary pelvic or sacral ES treated by a single surgeon. All received modern chemotherapy and those that received radiation were treated with modern dosages.

RESULTS

Fifty-five percent were disease-free at latest follow-up (median, 83.1 mos). Sixty-one percent had ≥ 99% necrosis, which was associated with 65% disease-free survival. Larger size (P = 0.016) and the absence of metastatic disease (P = 0.005) was predictive of survival. Eighty-three percent of relapsed patients were DOD. Half of patients who received surgery alone or RT alone have NED while 57% of those who received S/RT have NED. Complication rates were 69% (S/RT), 75% (surgery alone), 10% (RT alone). Functional outcomes were similar.

CONCLUSION

Primary pelvic ES is localized at presentation in 50% and the absence of metastases is the strongest predictor for survival. Chemotherapy is key, but excellent histologic response is neither a guarantee nor a necessity for survival. More than one-third die despite an excellent histologic response and at least one-third with lung metastases survive. With chemotherapy, radiation, and surgery, reasonable control of disease can be achieved.

LEVEL OF EVIDENCE III

Case-control or retrospective cohort study.

[Hemipelvectomy for the treatment of high-grade sarcomas: Pronostic of chondrosarcomas compared to other histological types]

INTRODUCTION

The low incidence and histological heterogeneity of primary sarcomas located in the pelvis makes it difficult to find homogeneous cohorts.

OBJECTIVE

To describe the life and functional prognosis depending on the histological type of sarcoma in a series of locally advanced high-grade pelvis located sarcomas treated by hemipelvectomy.

METHODS

A descriptive epidemiological and functional study was conducted on 15 cases treated between 2006 and 2012. Survival analysis, functional assessment, and a comparative study by histological type were performed, comparing chondrosarcomas to other histological diagnoses.

RESULTS

The most frequent histological type was chondrosarcoma (46%), and the most frequent location was P2 (periacetabular) (73%). An internal hemipelvectomy was performed in 66% of cases, with a higher incidence (83%) in chondrosarcomas. Overall two-year survival was 54%, with higher survival in the chondrosarcoma group (67%) than in the other sarcomas (43%). Functional status depended on the type of intervention, with no differences in histological type or the performance of the reconstruction.

DISCUSSION AND CONCLUSIONS

Hemipelvectomy is a surgical procedure that is indicated for the treatment of locally advanced high grade pelvis located sarcomas, regardless of histological type. The incidence of limb preservation and overall survival is higher in chondrosarcomas compared to other sarcomas.

Resection of inferior pubic ramus tumors through a femoribus internus-perineal approach

An operative approach to the inferior pubic ramus that was utilized in four patients with various bone tumors in the inferior pubic ramus is described here. These patients were successfully managed though a femoribus internus (inner thigh)-perineal approach. Data concerning preoperative and postoperative symptoms, surgical procedures, and outcomes are presented. There was no recurrence in the four cases and the pain associated with an initial pelvic floor had completely resolved except one case. The slight limitation in range of motion of the left hip joint and pain were performed in the same case postoperatively. The Musculoskeletal Tumor Society scores were 28, 15, 25, and 18 at the final follow-up. A typical case is described in full and our experience concerning surgical indications, and intraoperative issues in tumor patients discussed. The purpose of this paper is to recommend that the femoribus internus-perineal approach be used to resect the inferior pubic ramus, whether affected by osteomyelitis, bone tumor, or tuberculosis, but especially in patients with tumors.

Femur performed better than tibia in autologous transplantation during hemipelvis reconstruction

BACKGROUND

Pelvic reconstruction after hemipelvectomy can greatly improve the weight-bearing stability of the supporting skeleton and improve patients' quality of life. Although an autograft can be used to reconstruct pelvic defects, the most suitable choice of autograft, i.e., the use of either femur or tibia, has not been determined. We aimed to analyze the mechanical stresses of a pelvic ring reconstructed using femur or tibia after hemipelvectomy using finite element (FE) analysis.

METHODS

FE models of normal and reconstructed pelvis were established based on computed tomography images, and the stress distributions were analyzed under physiological loading from 0 to 500 N in both intact and restored pelvic models using femur or tibia.

RESULTS

The vertical displacement of the intact pelvis was less than that of reconstructed pelvis, but there was no significant difference between the two reconstructed models. In FE analysis, the stress distribution of the intact pelvic model was bilaterally symmetric and the maximum stresses were located at the sacroiliac joint, arcuate line, ischiatic ramus, and ischial tuberosity. The maximum stress in each part of the reconstructed pelvis greatly exceeded that of the intact model. The maximum von Mises stress of the femur was 13.9 MPa, and that of the tibia was 6.41 MPa. However, the stress distribution was different in the two types of reconstructed pelvises. The tibial reconstruction model induced concentrated stress on the tibia shaft making it more vulnerable to fracture. The maximum stress on the femur was concentrated on the connections between the femur and the screws.

CONCLUSIONS

From a biomechanical point of view, the reconstruction of hemipelvic defects with femur is a better choice.

Infection after surgical resection for pelvic bone tumors: an analysis of 270 patients from one institution

BACKGROUND

Surgical treatment of pelvic tumors with or without acetabular involvement is challenging. Primary goals of surgery include local control and maintenance of good quality of life, but the procedures are marked by significant perioperative morbidity and complications.

QUESTIONS/PURPOSES

We wished to (1) evaluate the frequency of infection after limb salvage surgical resection for bone tumors in the pelvis; (2) determine whether infection after these resections is associated with particular risk factors, including pelvic reconstruction, radiotherapy or chemotherapy, type of resection, and age; and (3) analyze treatment of these infections, particularly with respect to the need of additional surgery or hemipelvectomy.

METHODS

From 1975 to 2010, 270 patients with pelvic bone tumors (149 with chondrosarcoma, 40 with Ewing's sarcoma, 27 with osteosarcoma, 18 with other primary malignant tumors, 11 with metastatic tumors, and 25 with primary benign tumors) were treated by surgical resection. Minimum followup was 1.1 years (mean, 8 years; range, 1-33 years). The resection involved the periacetabular area in 166 patients. In 137 patients reconstruction was performed; in 133 there was no reconstruction. Chart review ascertained the frequency of deep infections, how they were treated, and the frequency of resection arthroplasty or hemipelvectomies that occurred thereafter.

RESULTS

A total of 55 patients (20%) had a deep infection develop at a mean followup of 8 months. There were 20 infections in 133 patients without reconstruction (15%) and 35 infections in 137 patients with reconstruction (26 %). Survivorship rates of the index procedures using infection as the end point were 87%, 83%, and 80% at 1 month, 1 year, and 5 years, respectively. Infection was more common in patients who underwent pelvic reconstruction after resection (univariate analysis, p = 0.0326; multivariate analysis, p = 0.0418; odds ratio, 1.7718; 95% CI, 1.0243-3.0650); no other risk factors we evaluated were associated with an increased likelihood of infection. Despite surgical débridements and antibiotics, 16 patients (46%) had the implant removed and five (9%) underwent external hemipelvectomy (four owing to infection and one as a result of persistent infection and local recurrence).

CONCLUSIONS

Infection is a common complication of pelvic resection for bone tumors. Reconstruction after resection is associated with an increased risk of infection compared with resection alone, without significant difference in percentage between allograft and metallic prosthesis. When infection occurs, it requires removal of the implant in nearly half of the patients who have this complication develop, and external hemipelvectomy sometimes is needed to eradicate the infection.

Computer-assisted navigation in orthopedic surgery

Computer-assisted navigation has a role in some orthopedic procedures. It allows the surgeons to obtain real-time feedback and offers the potential to decrease intra-operative errors and optimize the surgical result. Computer-assisted navigation systems can be active or passive. Active navigation systems can either perform surgical tasks or prohibit the surgeon from moving past a predefined zone. Passive navigation systems provide intraoperative information, which is displayed on a monitor, but the surgeon is free to make any decisions he or she deems necessary. This article reviews the available types of computer-assisted navigation, summarizes the clinical applications and reviews the results of related series using navigation, and informs surgeons of the disadvantages and pitfalls of computer-assisted navigation in orthopedic surgery.

Multidisciplinary management of soft tissue sarcoma

Soft tissue sarcoma is a rare malignancy, with approximately 11,000 cases per year encountered in the United States. It is primarily encountered in adults but can affect patients of any age. There are many histologic subtypes and the malignancy can be low or high grade. Appropriate staging work up includes a physical exam, advanced imaging, and a carefully planned biopsy. This information is then used to guide the discussion of definitive treatment of the tumor which typically involves surgical resection with a negative margin in addition to neoadjuvant or adjuvant external beam radiation. Advances in imaging and radiation therapy have made limb salvage surgery the standard of care, with local control rates greater than 90% in most modern series. Currently, the role of chemotherapy is not well defined and this treatment is typically reserved for patients with metastatic or recurrent disease and for certain histologic subtypes. The goal of this paper is to review the current state of the art in multidisciplinary management of soft tissue sarcoma.

Reconstruction of a large external hemipelvectomy defect after chordoma resection using a 5-component chimeric rotational flap

Management of complex lumbosacral neoplastic disease presents unique challenges and requires a multidisciplinary approach. Large pelvic tumors may require external hemipelvectomy where an entire lower extremity including the hemipelvis is removed with disarticulation of the sacroiliac joint and symphysis pubis. When external hemipelvectomy is performed, the reconstructive surgeon must consider osseous reconstruction for structural pelvic support, the elimination of dead space, protection of implanted hardware, intra-abdominal support, and skin coverage. Reconstruction must minimize wound healing morbidity, operative time and the number of operative sites, and maximize the potential for rehabilitation. We present a case demonstrating use of a rotational chimeric flap for the reconstruction of an external hemipelvectomy defect.

Biological reconstruction following the resection of malignant bone tumors of the pelvis

Background. Surgical treatment of malignant pelvic bone tumors can be very challenging. The objective of this retrospective study was to evaluate the oncological as well as the clinical and functional outcome after limb salvage surgery and biological reconstruction. Methods. The files of 27 patients with malignant pelvic bone tumors, who underwent surgical resection at our department between 2000 and 2011, were retrospectively analyzed (9 Ewing's sarcoma, 8 chondrosarcoma, 4 osteosarcoma, 1 synovial sarcoma, 1 malignant fibrous histiocytoma, and 4 carcinoma metastases). Results. After internal hemipelvectomy reconstruction was performed by hip transposition (n = 16), using autologous nonvascularised fibular graft (n = 5) or autologous iliac crest bone graft (n = 2). In one patient a proximal femor prothetis and in three patients a total hip prosthesis was implanted at the time of resection. The median follow-up was 33 months. Two- and five-year disease-specific survival rates of all patients were 86.1% and 57.7%, respectively. The mean functional MSTS score was 16.5 (~55%) for all patients. Conclusion. On the basis of the oncological as well as the clinical and functional outcome, biological reconstruction after internal hemipelvectomy seems to be a reliable technique for treating patients with a malignant pelvic bone tumor.