Acetabular metastases: planning for reconstruction and review of results

Management of metastatic bone disease of the pelvis: current concepts

PURPOSE

Metastatic disease of the pelvis is frequently associated with severe pain and impaired ambulatory function. Depending on the patient's characteristics, primary tumor, and metastatic pelvic disease, the treatment choice may be varied. This study aims to report on the current management options of metastatic pelvic disease.

METHODS

We comprehensively researched multiple databases and evaluated essential studies about current concepts of managing a metastatic bone disease of the pelvis, focusing on specific indications as well as on the result of treatment.

RESULTS

Pelvic metastases not in the periacetabular region can be managed with modification of weight-bearing, analgesics, bisphosphonates, chemotherapy and/or radiotherapy. Minimally invasive approaches include radiofrequency ablation, cryoablation, embolization, percutaneous osteoplasty, and percutaneous screw placement. Pathological or impending periacetabular fracture, excessive periacetabular bone defect, radioresistant tumor, and persistent debilitating pain despite non-surgical treatment and/or minimally invasive procedures can be managed with different surgical techniques. Overall, treatment can be divided into nonoperative, minimally invasive, and operative based on specific indications, the expectations of the patient and the lesion.

CONCLUSION

Different treatment modalities exist to manage metastatic pelvic bone disease. Decision-making for the most appropriate treatment should be made with a multidisciplinary approach based on a case-by-case basis.

Epidemiology and survival factors for sarcoma patients in minority populations: a SEER-retrospective study

Background

Epidemiologic studies have demonstrated race as a predictor of worse oncological outcomes. To better understand the effect of race on oncological outcomes, we utilized the Surveillance, Epidemiology, and End Results (SEER) database to determine what treatment courses are provided to minority patients and how this impacts survival.

Materials and methods

A retrospective review of bone and soft tissue sarcoma cases was performed using the SEER database for a minimum 5-year survival rate (SR) using Kaplan-Meier curves. Categorical variables were compared using Pearson's χ2 test and Cramer V. Kaplan-Meier curves were used to determine survival rates (SR) and Cox regression analysis was used to determine hazard ratios (HRs).

Results

Races that had an increased risk of death included Native American/Alaska Native (NA/AN) [hazard ratio (HR): 1.36, 95% confidence interval (CI): 1.049-1.761, p = 0.020) and Black (HR = 1.17, 95% CI: 1.091-1.256, p < 0.001). NA/AN individuals had the lowest SR (5-year SR = 70.9%, 95% CI: 63.8-78.0%, p < 0.001). The rate of metastasis at diagnosis for each race was 13.07% - Hispanic, 10.62% - NA/AN, 12.77% - Black, 10.61% - Asian/Pacific Islander (A/PI), and 9.02% - White individuals (p < 0.001). There were increases in the rate of metastasis at diagnosis and decreases in rates of surgical excision for Hispanic and Black patients (p < 0.001).

Conclusion

Race is determined to be an independent risk factor for death in NA/AN and Black patients with sarcomas of the extremities. Access to healthcare and delay in seeking treatment may contribute to higher rates of metastasis upon diagnosis for minority patients, and decreased rates of surgical excision could be associated with poor follow up and lack of resources.

Operative management of metastatic disease of the acetabulum: review of the literature and prevailing concepts

Metastatic disease of the periacetabular region is a common problem in orthopaedic oncology, associated with severe pain, decreased mobility, and substantial decline of the quality of life. Conservative management includes optimisation of pain management, activity modification, and radiation therapy. However, patients with destructive lesions affecting the weight-bearing portion of the acetabulum often require reconstructive surgery to decrease pain and restore mobility. The goal of surgery is to provide an immediately stable and durable construct, allowing immediate postoperative weight-bearing and maintaining functional independence for the remaining lifetime of the patient. A variety of surgical techniques have been reported, most of which are based upon cemented total hip arthroplasty, but also include porous tantalum implants and percutaneous cementoplasty. This review discusses the various reconstructive concepts and options, including their respective indications and outcome. A reconstructive algorithm incorporating different techniques and strategies based upon location and quality of remaining bone is also presented.

Augmenting Pathologic Acetabular Bone Loss With Photodynamic Nails to Support Primary Total Hip Arthroplasty

Background

Pathologic acetabular defects can undermine the stability and osseointegration of a primary total hip arthroplasty (THA) acetabular component. Our service has used photodynamic nails (PDNs) in a modified Harrington technique to provide space-filling stability to a primary acetabular implant without impeding local osseointegration. Here we describe our experience with PDN-augmented THAs.

Methods

An institutional review board-approved retrospective analysis of all patients who underwent PDN-augmented THA in the management of severe (Harrington class II or III) acetabular defects from September 1, 2020 to May 1, 2021 with at least 6 months of follow-up was performed. The primary outcome was implant survivorship. Comparisons between preoperative and 6-week postoperative visual analogue pain scores were made using the Mann-Whitney U test.

Results

Six patients were included in this case series, 5 with metastatic cancer and 1 with pelvic discontinuity and avascular necrosis following failed attempted acetabular fixation. The mean follow-up duration was 10.3 ± 4.3 months. The mean age was 75.5 ± 4.7 years, mean body mass index 27.3 ± 5.6, and 5 patients were female. All but 1 patient was American Society of Anesthesiologists (ASA) class III. Two patients required acetabular revisions, one for aseptic loosening and a second for a pathologic fracture secondary to disease progression. One patient passed away 90 days after the procedure. The mean visual analogue pain score significantly improved from 7.8 ± 1.6 to 2.0 ± 1.4 six weeks after surgery (P = .008).

Conclusions

PDN augmentation of the periacetabular bone of patients with large pelvic defects yields durable pain relief and function in vulnerable hosts. PDN should be considered a part of the reconstructive surgeon’s armamentarium.

A Tailored Approach for Appendicular Impending and Pathologic Fractures in Solid Cancer Metastases

Simple Summary

Patients with bone metastases often suffer with complications, such as bone fractures, which have a substantial negative impact on clinical outcomes. To optimize clinical results, a tailored approach should be defined for managing impending or pathologic fractures in each individual case. The ability to control systemic disease, the extent, location and nature of bone metastases, and the biology of the underlying tumor, are the main factors that will define the strategy to follow.

Abstract

Advances in medical and surgical treatment have played a major role in increasing the survival rates of cancer patients with metastatic bone disease. The clinical course of patients with bone metastases is often impaired by bone complications, such as bone fractures, which have a substantial negative impact on clinical outcomes. To optimize clinical results and prevent a detrimental impact on patients’ health, a tailored approach should be defined for any given patient. The optimal management of impending or pathologic fractures is unknown and relies on a multidisciplinary approach to tailor clinical decisions to each individual patient. The ability to control systemic disease, the extent, location and nature of bone metastases, and the biology of the underlying tumor, are the main factors that will define the strategy to follow. The present review covers the most recent data regarding impending and pathologic fractures in patients with bone metastases, and discusses the medical and surgical management of patients presenting with metastatic bone disease in different clinical settings.

Surgical treatment of peri-acetabular metastatic disease: Retrospective, multicentre study of 91 THA cases

INTRODUCTION

The occurrence of peri-acetabular metastasis (PAM) is a turning point in the progression of cancer because the disabling pain prevents the patient from walking or makes it difficult. Recent progress in controlling cancers that spread to the bone and controlling local bone destruction justify this national study. Since the data in France is incomplete or based on small studies, we analysed a multicentre retrospective cohort of patients with PAM who underwent total hip arthroplasty (THA) to evaluate 1) the clinical and radiological outcomes and 2) the factors impacting patient survival.

HYPOTHESIS

The clinical outcomes, complication rate and survivorship are comparable to that of recent published studies.

METHODS

Ninety-one patients (27 men, 64 women) with a mean age of 62.7±10.5 years (extremes 38 and 88) with PAM secondary to breast cancer [42 patients (46%)] or lung cancer [20 patients (22%)] underwent THA. The metastasis was the first sign of cancer in 33 cases (36%). Concurrent visceral metastases were present in 30 patients (33%), multiple peripheral bone metastasis in 48 patients (53%) and synchronous spine metastasis in 39 patients (43%). The most common construct was a cemented stem with metal reinforcement cage and cemented dual mobility cup [71 times (78%), while 85/91 had a dual mobility cup (93%)].

RESULTS

Elimination or reduction of pain was reported in 81 patients (91%). Overall walking ability was deemed normal or acceptable in 74 patients (83%). Six patients died (7%) before the end of the 3rd month. There were seven general complications (8%) including five thromboembolic events. There were 22 complications related to the surgical procedure in 20 patients (22%) that required surgical revision, including 10 surgical site infections (11%) and 3 dislocations (3%) (one concerning a dual mobility cup and 2 after single mobility cup). The median survivorship all causes combined was 19.5 months; it was 23.7 months for patients with breast cancer and 8.9 months for those with lung cancer.

CONCLUSION

Despite different endpoints being used, the clinical outcomes in our study are like those in other published studies, as were the incidence of surgery-related complications and the survivorship. The recommended surgical technique is the implantation of an acetabular reinforcement cage, curettage with cement filling of osteolytic areas, dual mobility cup and cemented stem followed by radiation therapy. The role of THA versus interventional radiology procedures must still be determined.

LEVEL OF EVIDENCE

IV, retrospective study without control group.

Comparison of Porous Tantalum Acetabular Implants and Harrington Reconstruction for Metastatic Disease of the Acetabulum

BACKGROUND

The periacetabular region is a common location for metastatic disease. Although large lytic acetabular defects are commonly treated with a hip arthroplasty with a cemented component according to a Harrington-style reconstruction, the use of highly porous uncemented tantalum acetabular components has been described. Currently, there are no direct comparisons of these reconstructive techniques. The purpose of this study was to compare the outcomes of the Harrington technique and tantalum acetabular component reconstruction for periacetabular metastases.

METHODS

From 2 tertiary sarcoma centers, we retrospectively reviewed 115 patients (70 female and 45 male) with an acetabular metastatic defect who had been treated between 2002 and 2015 with a total hip arthroplasty using either the cemented Harrington technique (78 patients) or a tantalum acetabular reconstruction (37 patients). The mean patient age was 61 years, and the most common Eastern Cooperative Oncology Group status was 3 (39 patients). The mean follow-up for surviving patients was 4 years.

RESULTS

An additional surgical procedure was performed in 24 patients (21%). Harrington-style reconstructions were more likely to require a reoperation compared with tantalum reconstructions (hazard ratio [HR], 4.59; p = 0.003). The acetabular component was revised in 13 patients (11%); 5 patients (4%) underwent revisions that were due to loosening of the acetabular component. The 10-year cumulative incidence of revision of the acetabular component for loosening was 9.6% in the Harrington group and 0% in the tantalum group (p = 0.09). The mean Harris hip score significantly improved following reconstruction (31 to 67 points; p < 0.001), with no significant difference (p = 0.29) between groups.

CONCLUSIONS

In patients with periacetabular metastatic disease treated with total hip arthroplasty, an acetabular reconstruction strategy utilizing highly porous tantalum acetabular components and augments successfully provided patients with a more durable construct with fewer complications compared with the cemented Harrington-style technique.

LEVELS OF EVIDENCE

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

Biomechanics study of a 3D printed sacroiliac joint fixed modular hemipelvic endoprosthesis

BACKGROUND

Reconstructing pelvic type II + III defect caused by bone tumors is challenging. The purpose of this study was to explore the in vitro biomechanical properties of a reconstructed pelvis after periacetabular resection using three-dimensional (3D) printed sacroiliac joint (SIJ) fixed modular hemipelvic endoprosthesis.

METHODS

Type II/II + III pelvic resection was simulated on an artificial pelvic model. The bilateral acetabulum and pubis were constrained, and the pelvis was maintained in a human physiological standing position. A vertically continuous linear load was applied on the upper face of S1 until obvious unloading or fixed failure occurred. A noncontact optical 3D strain measuring system was used to measure the strains and displacements at the selected area.

FINDINGS

The strain at the points of interest did not obviously differ between the intact and reconstructed pelvis models. The difference in the displacement on the reconstructed side was 0.237 mm, and that on the contralateral side was 0.245 mm. The maximum differences in the displacement at the acetabulum were 0.209 mm (vertical) and 0.324 mm (horizontal). A crack at the superior rim of the contralateral acetabulum occurred, and failure loading of 7.126 kN.

INTERPRETATION

The prosthesis in this study showed satisfactory mechanical properties and structural stability. According to the mechanical evaluations, the 3D printed sacroiliac-stabilized hemipelvic endoprosthesis can be used to reconstruct a stable acetabular structure, and there was little influence on the mechanical properties of the surrounding bone structures. The prosthesis design is reasonable, and the mechanical distribution on the reconstructed side was similar to that on the contralateral side.

A Novel Tripod Percutaneous Reconstruction Technique in Periacetabular Lesions Caused by Metastatic Cancer

BACKGROUND

Metastatic lesions in the periacetabular region can cause pain and immobility. Symptomatic patients are often treated surgically with a total hip replacement using various modified Harrington methods. These open surgical procedures confer inherent risks. Prolonged recovery and potential complications may delay adjuvant radiation and systemic therapy.

METHODS

We describe a novel technique for acetabular reconstruction. Three large-bore cannulated screws are placed percutaneously under fluoroscopy in a tripod configuration to reinforce the mechanical axes of the acetabulum. Increased stability improves pain control and permits weight-bearing.

RESULTS

Twenty consecutive patients with periacetabular metastases were treated using the tripod technique. Eighteen patients (90%) had Harrington class-III lesions, and 2 patients had Harrington class-II lesions. The mean surgical time was 2.3 hours. Sixteen patients (80%) were able to get out of bed on postoperative day 1. At 3 months postoperatively, there was significant improvement in pain as documented on their visual analog scale (p < 0.01) and in functionality as measured by the Eastern Cooperative Oncology Group score (p < 0.01). The mean follow-up time was 7 months (range, 0.6 to 20 months). At the most recent follow-up, only 3 among the 16 surviving patients were using opioids chronically for pain. Total hip arthroplasty was performed in 4 patients (20%) in a staged fashion using the previously placed screws as support for a cemented cup and obviating the need for a cage device. Of the 16 patients, 15 could walk either independently (6 patients) or using an ambulatory aid (9 patients). Eight patients with the primary tripod reconstruction survived >6 months postoperatively. They were found to have either new bone formation filling the defects or healing of the pathological fractures. There has been no implant loosening or failure.

CONCLUSIONS

The tripod technique is a novel application to provide safe and effective pain relief in the context of periacetabular metastatic disease. It can be easily converted to support a cemented acetabular cup for a total hip replacement should disease progression occur. This technique provides an alternative to open surgery as currently practiced in these patients.

LEVEL OF EVIDENCE

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

Improving functional outcome and quality of life for patients with metastatic lesion of acetabulum undergoing cement augmentation

There is an increased enthusiasm in treating osteolytic metastatic acetabulum via injecting polymethyl-methacrylate (PMMA) as a bone filler to provide pain relief and potential structural support. The aim of this respective study is to determine the function and quality of life improvement after cement acetabuloplasty.Thirty two patients underwent acetabular cement augmentation between May 2014 and March 2018 were respectively reviewed. Isolated percutaneous acetabuloplasty (PA) was performed in 15 patients (group A) while radiofrequency ablation with PA (RFA-PA) in 12 patients (group B). Together with PA, open reconstructive surgery on ipsilateral femur was performed in another 5 cases (group C). Pre- and posttreatment functional evaluation and quality of life (QoL) assessment were carried out.The average followup duration was 11.5 (range, 3-36) months. None of major complications occurred. 81.2% (26/32) of patients achieved complete pain relief. Reduction of pain intensity and improvement of functional status achieved significantly differences after treatment (P = .00). Significant improvement (P = .00) was observed in scales of global QoL and pain-related restrictions in daily activities. Both isolated PA and RFA-PA procedures were equally effective towards the improvement of function and quality of life (P > .05). Regarding 5 patients in group C, pain intensity decreased when loading the affected limb and they could walk with crutches or cane.Bone cement acetabuloplasty is an adequate and effective mini-invasive procedure to relieve pain, restore function, and enhance the quality of life of patients for as long as possible in metastatic patients with short life expectancy. Ipsilateral surgery appears to be safe and well tolerated.

Using 3D models in orthopedic oncology: presenting personalized advantages in surgical planning and intraoperative outcomes

Background

Three Dimensional (3D) printed models can aid in effective pre-operative planning by defining the geometry of tumor mass, bone loss, and nearby vessels to help determine the most accurate osteotomy site and the most appropriate prosthesis, especially in the case of complex acetabular deficiency, resulting in decreased operative time and decreased blood loss.

Methods

Four complicated cases were selected, reconstructed and printed. These 4 cases were divided in 3 groups of 3D printed models. Group 1 consisted of anatomical models with major vascular considerations during surgery. Group 2 consisted of an anatomical model showing a bone defect, which was intended to be used for substantial instrumentation, pre-operatively. Group 3 consisted of an extra-compartmental bone tumor which displayed a deteriorated cortical outline; thus, using CT and MRI fused images to reconstruct the model accurately. An orthopedic surgeon created the 3D models of groups 1 and 2 using standard segmentation techniques. Because group 3 required complex techniques, an engineer assisted during digital model construction.

Results

These models helped to guide the orthopedic surgeon in creating a personalized pre-operative plan and a physical simulation. The models proved to be beneficial and assisted with all 4 cases, by decreasing blood loss, operative time and surgical incision length, and helped to select the appropriate acetabular supporting ring in complex acetabular deficiency, pre-operatively.

Conclusion

Qualitatively, using 3D printing in tumor cases, provides personalized advantages regarding the various characteristics of each skeletal tumor.

Reconstruction of the hip after resection of periacetabular oncological lesions: a systematic review

Aims

Reconstruction of the acetabulum after resection of a periacetabular malignancy is technically challenging and many different techniques have been used with varying success. Our aim was to prepare a systematic review of the literature dealing with these techniques in order to clarify the management, the rate of complications and the outcomes.

Patients and Methods

A search of PubMed and MEDLINE was conducted for English language articles published between January 1990 and February 2017 with combinations of key search terms to identify studies dealing with periacetabular resection with reconstruction in patients with a malignancy. Studies in English that reported radiographic or clinical outcomes were included. Data collected from each study included: the number and type of reconstructions, the pathological diagnosis of the lesions, the mean age and follow-up, gender distribution, implant survivorship, complications, functional outcome, and mortality. The results from individual studies were combined for the general analysis, and then grouped according to the type of reconstruction.

Results

A total of 57 studies met the inclusion criteria and included 1700 patients. Most lesions were metastatic (41%), followed by chondrosarcoma (29%), osteosarcoma (10%), Ewing’s sarcoma (7%), and multiple myeloma (2%). The techniques of reconstruction were divided into seven types for analysis: those involving a Harrington reconstruction, a saddle prosthesis, an allograft and allograft prosthesis composite, a pasteurised autograft, a porous tantalum implant, a custom-made prosthesis and a modular hemipelvic reconstruction. The rate of complications was 50%, with infection (14%) and instability (8%) being the most common. Mortality data were available for 1427 patients (84%); 50% had died of disease progression, 23% were alive with disease, and 27% had no evidence of disease at a mean follow-up of 3.4 years (0 to 34).

Conclusion

Both the rate of complications and mortality are high following resection of oncological periacetabular lesions and reconstruction. Many types of reconstruction have been used with unique challenges and complications for each technique. Newer prostheses, including custom-made prostheses and porous tantalum implants and augments, have shown promising early functional and radiographic outcomes.

Cite this article: Bone Joint J 2018;100-B(1 Supple A):22–30.

Use of minimally invasive spine surgical instruments for the treatment of bone tumors

INTRODUCTION

Orthopedic oncologists often encounter patients with minor bony lesions that are difficult to access surgically and therefore require large exposures out of proportion to the severity of disease that confer significant patient morbidity. Minimally invasive surgical techniques offer the advantage of smaller incisions, shorter operative times, decreased tissue damage, and decreased costs. A variety of surgical procedures have emerged using minimally invasive technologies, particularly in the field of spine surgery. Areas covered: In this article, we describe the Minimal Exposure Tubular Retractor (METRx^TM) System which is a minimally invasive surgical device that utilizes a series of dilators to permit access to a surgical site of interest. This system was developed for use in treatment of disc herniation, spinal stenosis, posterior lumbar interbody fusion, transforaminal lumbar interbody fusion and spinal cord stimulation implantation. We also describe novel uses of this system for minimally invasive biopsy and treatment of benign and metastatic bone lesions at our institution. Expert commentary: Minimally invasive surgical techniques will continue to expand into the field of orthopedic oncology. With a greater number of studies proving the safety and effectiveness of this technique, the demand for minimally invasive treatments will grow.

Outcome after Surgery for Metastases to the Pelvic Bone: A Single Institutional Experience

BACKGROUND

The pelvic bone is the most common site of bone metastases following the axial skeleton. Surgery on the pelvic bone is a demanding procedure. Few studies have been published on the surgical outcomes of metastasis to the pelvic bone with only small numbers of patients involved. This study sought to analyze the complications, local progression and survival after surgery for metastasis to the pelvic bone on a larger cohort of patients.

METHODS

We analyzed 83 patients who underwent surgery for metastases to the pelvic bone between the years 2000 and 2015. There were 41 men and 42 women with a mean age of 55 years. Possible factors that might be associated with complications, local progression and survival were investigated with regard to patient demographics and disease-related and treatment-related variables.

RESULTS

The overall complication rate was 16% (13/83). Advanced age (> 55 years, p = 0.034) and low preoperative serum albumin levels (≤ 39 g/L, p = 0.001) were associated with increased complication rates. In patients with periacetabular disease, the complication rate was higher in those who underwent total hip replacement arthroplasty (THR) than those who did not (p = 0.030). Local progression rate was 46% (37/83). The overall median time to local progression was 26 ± 14.3 months. The median time from local progression to death was 13 months (range, 0 to 81 months). The local progression-free survival was 52.6% ± 6.4% at 2 years and 36.4%± 7.6% at 5 years, respectively. Presence of skip lesions (p = 0.017) and presence of visceral metastasis (p = 0.027) were found to be significantly associated with local progression. The median survival of all patients was 24 months. The 2-year and 3-year survival rates were 52.5% ± 5.9% and 35.6% ± 6%, respectively. Metastasis from the kidney, breast, or thyroid or of hematolymphoid origin (p = 0.014), absence of visceral metastasis (p = 0.017) and higher preoperative serum albumin levels (p = 0.009) were associated with a prolonged survival.

CONCLUSIONS

Advanced age and low serum albumin levels were associated with high complication rates. Local progression after surgery for metastases to the pelvic bone was affected by the presence of skip lesions, not by surgical margins. Primary cancer type, serum albumin level and visceral metastasis influenced survival.

Reconstruction of metastatic acetabular defects using a modified Harrington procedure

BACKGROUND AND PURPOSE

Metastases engaging the acetabulum result in significant disability. We investigated the outcome after curettage and reconstruction of the defect with a protrusio cage, retrograde screws, and a cemented total hip arthroplasty.

PATIENTS AND METHODS

We retrospectively identified 70 consecutive patients who were surgically treated for metastatic disease of the acetabulum between 1995 and 2012 using the above technique. The type of primary tumor, extent of the disease, degree of acetabular erosion, and type of implant used were identified. Patient and implant survival, complications, and functional outcome were recorded.

RESULTS

There were no mortalities in the perioperative period (30 days after surgery). Median overall patient survival was 12 months. Prosthesis survival was 92% at 1 year and 89% at 5 years. One third of the patients suffered a complication, the most frequent one being dislocation. The functional outcome was good. Multiple skeletal or visceral metastases and specific types of cancer were associated with poor patient survival.

INTERPRETATION

Reconstruction of metastatic acetabular defects using a protrusio cage stabilized with retrograde screws and a cemented total hip arthroplasty is a safe procedure that provides efficient relief of symptoms. Patients with extensive disease, especially when diagnosed with specific types of cancer, have a very poor prognosis. The complication rate is substantial, the most frequent being dislocation. However, revision surgery is seldom required and prosthesis survival is high.

Percutaneous Acetabuloplasty Compared With Open Reconstruction for Extensive Periacetabular Carcinoma Metastases

For destructive metastatic periacetabular disease, options include open acetabular reconstruction or percutaneous cement acetabuloplasty (PA). We reviewed 28 consecutive patients with Harrington grade II or III lesions, 17 who underwent Harrington-type or anti-protrusio reconstruction and 11 who underwent PA. Primary outcome measures were performance status (PS), ambulatory status (0=unassisted ambulation, 1=assisted ambulation, 2=nonambulatory), and 10-point VAS score. The surgery group had better pain reduction than the PA group at 3 months (3.6 vs. 1.5 points, P=0.04), and a trend at final follow-up (3.8 vs. 1.4 points, P=0.06). Improvement in ambulatory status was better in the surgery group at 3 months only (0.53 vs. -0.14, P=0.03). Thus compared with PA, open reconstruction may provide improved pain relief and ambulation.

A rare case of iliac crest metastasis from acinic cell carcinoma of parotid gland

A case of acinic cell carcinoma of the right parotid gland metastasizing to the right iliac crest is presented. Generally, for this rare low-grade malignant salivary gland neoplasm, 20% of cases may have local recurrences whereas about 10% of cases have distant metastases. They may arise many years after the initial presentation of the original tumor. The most frequent locations are the cervical lymph nodes, liver, lungs, contralateral orbit and bones. Occurrence in the appendicular skeleton is very rare and in our knowledge this is the first report of metastases to the pelvis.

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.

Surgical intervention of nonvertebral osseous metastasis

BACKGROUND

Nonvertebral osseous metastases can result in pain and disability. The goals of surgical intervention are to reduce pain and to improve function if nonsurgical treatment fails. The indications for proceeding with surgical intervention depend on anatomic location, amount of local destruction, extent of skeletal and visceral disease and, most important, the patient's performance status and life expectancy.

METHODS

This article reviews the evaluation and treatment of metastatic nonvertebral osseous lesions from the perspective of the orthopedic surgeon, based mainly on an assessment of the surgical literature.

RESULTS

This article summarizes the approaches to preoperative evaluation, patient selection, and medical optimization. Guidelines for estimating osseous stability and fracture risk are discussed, and surgical implants and their relation to postoperative outcomes are examined. This review also describes less invasive ablative procedures currently available.

CONCLUSIONS

The surgical management of nonvertebral osseous metastases involves multidisciplinary collaboration. The surgical construct must be a stable, reliable, and durable intervention that is individually tailored and matched to a patient's prognosis and performance status.

Pelvic resections

The complexity of pelvic anatomy and the extent of tumor growth makes treatment of patients with primary bone sarcomas in the pelvis difficult in terms of local control. Before the 1970s, most tumors in the bony pelvis were surgically treated with hindquarter amputation. Currently, improved techniques for clinical staging, adjuvant treatments, evolutions in metallurgy, and development of new surgical techniques make limb-salvage surgery and reconstruction possible alternatives to hemipelvectomy and resection-arthrodesis. The advantages of amputation over resections at the pelvis are a lower incidence of complications, a limited area at risk for recurrence, and a faster recovery time compared with all but the most limited pelvic resections. The disadvantages, especially after periacetabular resections, are leg-length discrepancy and impaired hip and gait function. The indication for limb salvage is the ability to obtain wide margins without compromising survival and function. Although having to resect the sciatic nerve to obtain adequate margins does not always mean that an amputation should be performed, the combination of a major pelvic resection and the functional consequences of sciatic nerve resection results in an extremity usually not worth saving; loss of femoral nerve function does not result in a significant gait disturbance, especially if the hemipelvis is stable. Reconstruction options after major pelvic resections have also evolved, but they remain difficult, especially when the acetabulum is involved.

Clinical outcome and quality of life after surgery for peri-acetabular metastases

We set out to determine the impact of surgery on quality of life and function in patients who had undergone surgery for symptomatic peri-acetabular metastases. From a prospective database we retrospectively reviewed 46 consecutive patients who had been treated operatively between June 2003 and June 2009. The mean age of the patients was 56.4 years (20 to 73) and the mean post-operative follow-up was 19.2 months (4 to 70). Functional evaluation and quality-of-life assessments were performed. At the most recent follow-up, 26 patients (56.5%) were alive. Their median survival time was 25.0 months. Ten major postoperative complications had occurred in eight patients (17.4%). The mean post-operative Musculoskeletal Tumor Society score (MSTS 93) was 56.3% (6.7% to 90.0%). Improvement in the Eastern Cooperative Oncology Group (ECOG) performance status was seen in 32 patients (69.6%). On the European Organisation for Research and Treatment of Cancer core quality-of-life questionnaire (QLQ-C30) measure of global health status there was a statistically significant improvement from the patients’ pre-operative status (42.8 (sd 13.7)) to that found at the latest follow-up (58.0 (sd 12.5)) (p = 0.001). The only statistically significant change in the nine symptom domains of the QLQ-C30 was a reduction in the mean level of pain (from 59.1 to 29.5 (out of 100)) (p < 0.001).

Surgery for patients with peri-acetabular metastases reduces pain and improves their quality of life, and has a low rate of surgical complications.

Metastases of the pelvis: does resection improve survival?

Limited data are available to compare the outcome of wide en bloc resection and curettage for pelvic metastases. Previous studies have reported that curettage is associated with high mortality and decreased survival compared to wide resection and have justified consideration of a radical surgical approach to achieve pain palliation and tumor control. In this study, we aimed to evaluate the role of curettage/marginal resection compared to wide en bloc resection for patients with pelvic metastases. The hypothesis was that wide resection does not improve survival even in patients with solitary pelvic metastases.Between 1985 and 2009, twenty-one patients with pelvic metastases were treated with wide resection (12 patients) and curettage/marginal resection (9 patients) and adjuvants. Sixteen patients had solitary pelvic metastases. At a mean of 28 months (range, 2-152 months), we found no difference in survival to death or local recurrence with wide en bloc resection compared to curettage or marginal resection, even in patients with solitary pelvic metastases. The overall survival to death and local recurrence was 30% and 47% at 60 months, respectively. Survival to death of patients treated with wide resection was 18% at 60 months compared to 62% at 60 months of patients treated with curettage/marginal resection; no difference in survival to death between wide resection and curettage/marginal resection was observed even in patients with solitary pelvic metastases. Survival to local recurrence of patients treated with wide en bloc resection was 67% at 36 months compared to 26% at 36 months of patients treated with curettage/marginal resection; this was also not statistically significant. One patient treated with wide resection for a solitary pelvic metastasis had a postoperative complication.

Encountering cancer or its sequelae at the hip

The orthopedist may need act as an adjunct to the medical oncologist in the management of the cancer patient with hip disease. While management of the cancer patient with routine hip pathology is relatively straightforward, the surgeon should be aware that the cancer patient may be on treatment protocols that affect wound healing, the immune system, and the risk of deep venous thrombosis. An additional factor that may complicate management of patients who have completed treatment of peripelvic cancer may be local radiation therapy, which can lead to necrosis of the acetabular bone stock. Operating on these patients must include consultation with previous radiation therapy providers to estimate the dose sustained by the local tissues under consideration. Greater than 500 cGy has been associated with high fixation failure rates in several series. Increased rates of infection and wound healing have also been noted secondary to long-term lymphatic obliteration caused by radiation. These concerns also affect the surgeon who must manage patients with acute metastatic disease. The principles of managing metastatic disease include recognizing the presence of lesions in bone about the hip, the occasional need for biopsy, the use of radiation in sensitive tumors, surgical stabilization of impending fracture, or joint replacement when needed. The amount of tumor, as well as the effect of chemotherapy and radiation on the healing process, potentially complicates these treatment modalities.

Percutaneous acetabuloplasty for metastatic acetabular lesions

BACKGROUND

Osteolytic metastases around the acetabulum are frequent in tumour patients, and may cause intense and drug-resistant pain of the hip. These lesions also cause structural weakening of the pelvis, limping, and poor quality of life. Percutaneous acetabuloplasty is a mini-invasive procedure for the management of metastatic lesions due to carcinoma of the acetabulum performed in patients who cannot tolerate major surgery, or in patients towards whom radiotherapy had already proved ineffective.

METHODS

We report a retrospective study in 25 such patients (30 acetabuli) who were evaluated before and after percutaneous acetabuloplasty, with regard to pain, mobility of the hip joint, use of analgesics, by means of evaluation forms: Visual Analog Scale, Harris Hip Score, Western Ontario and McMaster Universities Index of Osteoarthritis (WOMAC), Eastern Cooperative Oncology Group (ECOG). The results obtained were analysed using the chi2 Test and Fisher's exact test. Significance was sent at P < 0.05.

RESULTS

Marked clinical improvement was observed in all patients during the first six post-operative months, with gradual a worsening thereafter from deterioration of their general condition. Complete pain relief was achieved in 15 of our 25 (59%) of patients, and pain reduction was achieved in the remaining 10 (41%) patients. The mean duration of pain relief was 7.3 months. Pain recurred in three patients (12%) between 2 weeks to 3 months. No major complications occurred. There was transient local pain in most cases, and 2 cases of venous injection of cement without clinical consequences.

CONCLUSION

Percutaneous acetabuloplasty is effective in improving the quality of life of patients with osteolytic bone tumours, even though the improvement is observed during the first 6 months only. It can be an effective aid to chemo- and radiotherapy in the management of acetabular metastases.

Evaluation and treatment of pelvic metastases

Advances in systemic treatment of cancer have improved patients' survival and increased the number of patients presenting with metastases of the pelvic ring. Pelvic metastatic lesions may cause severe pain and functional disability. A multidisciplinary approach is fundamental for the management of these lesions. Lesions of the pelvis not directly involving the hip joint such as the ischium, pubis or sacroiliac area can generally be treated non-operatively with radiation alone or using minimally invasive procedures of radiofrequency ablation, cryosurgery and percutaneous osteoplasty. Periacetabular destructive lesions may require total hip replacement with reconstruction of the acetabulum dependent on the extent of the defect. Operative treatment should restore the mechanical stability of the hip joint, and preserve the mobility, independence and comfort of these patients.

A Biomechanical Study of Periacetabular Defects and Cement Filling

Periacetabular bone metastases cause severe pain and functional disability in cancer patients. Percutaneous acetabuloplasty (PCA) is a minimally invasive, image-guided procedure whereby cement is injected into lesion sites. Pain relief and functional restoration have been observed clinically; however, neither the biomechanical consequences of the lesions nor the effectiveness of the PCA technique are well understood. The objective of this study was to investigate how periacetabular lesion size, cortex involvement, and cement modulus affect pelvic bone stresses and strains under single-legged stance loading. Experiments were performed on a male cadaver pelvis under conditions of intact, periacetabular defect, and cement-filling with surface strains recorded at three strain gage locations. The experimental data were then employed to validate three-dimensional finite element models of the same pelvis, developed using computed tomography data. The models demonstrated that increases in cortical stresses were highest along the posterior column of the acetabulum, adjacent to the defect. Cortical stresses were more profoundly affected in the presence of transcortical defects, as compared to those involving only trabecular bone. Cement filling with a modulus of 2.2GPa was shown to restore cortical stresses to near intact values, while a decrease in cement modulus due to inclusion of BaSO4 reduced the restorative effect. Peak acetabular contact pressures increased less than 15% for all simulated defect conditions; however, the contact stresses were reduced to levels below intact in the presence of either cement filling. These results suggest that periacetabular defects may increase the vulnerability of the pelvis to fracture depending on size and cortical involvement and that PCA filling may lower the risk of periacetabular fractures.

Iliosacral resection for primary bone tumors: is pelvic reconstruction necessary?

Iliosacral resection for primary bone tumors creates a large unstable pelvic ring defect, the treatment of which remains controversial. We did this study to determine if skeletal reconstruction of such defects is necessary. Sixteen patients whose data were collected prospectively had iliosacral resection with a minimum followup of 12 months. The surgical and functional results of patients who had skeletal reconstruction (n = 4) were compared with the results of patients who did not have iliosacral repair (n = 12) using a case-control design. Function was evaluated by assessing impairment using the Musculoskeletal Tumor Society 1987 and 1993 rating scales, and disability was measured using the Toronto Extremity Salvage Score. Although all four iliosacral arthrodeses initially healed, one allograft used for reconstruction fractured and another was removed because of progressive lumbosacral spinal instability. Patients treated without pelvic reconstruction had fewer operative complications. Although the Toronto Extremity Salvage Score and the Musculoskeletal Tumor Society 1987 and 1993 scores were similar for both patient groups, those patients who were treated without reconstruction were less likely to require the use of an ambulatory assistive device, less likely to require narcotics or have chronic pain, and more likely to return to work. These results suggest that reconstruction of the skeletal defect to restore pelvic stability after iliosacral resection is not mandatory.

LEVEL OF EVIDENCE

Therapeutic study, Level III-1 (case-control study). See the Guidelines for Authors for a complete description of levels of evidence.