Outcome after pelvic sarcoma resection reconstructed with saddle prosthesis

Clinical outcome of pedestal cup endoprosthetic reconstruction after resection of a peri-acetabular tumour

Peri-acetabular tumour resections and their subsequent reconstruction are among the most challenging procedures in orthopaedic oncology. Despite the fact that a number of different pelvic endoprostheses have been introduced, rates of complication remain high and long-term results are mostly lacking.

In this retrospective study, we aimed to evaluate the outcome of reconstructing a peri-acetabular defect with a pedestal cup endoprosthesis after a type 2 or type 2/3 internal hemipelvectomy.

A total of 19 patients (11M:8F) with a mean age of 48 years (14 to 72) were included, most of whom had been treated for a primary bone tumour (n = 16) between 2003 and 2009. After a mean follow-up of 39 months (28 days to 8.7 years) seven patients had died. After a mean follow-up of 7.9 years (4.3 to 10.5), 12 patients were alive, of whom 11 were disease-free. Complications occurred in 15 patients. Three had recurrent dislocations and three experienced aseptic loosening. There were no mechanical failures. Infection occurred in nine patients, six of whom required removal of the prosthesis. Two patients underwent hindquarter amputation for local recurrence.

The implant survival rate at five years was 50% for all reasons, and 61% for non-oncological reasons. The mean Musculoskeletal Tumor Society score at final follow-up was 49% (13 to 87).

Based on these poor results, we advise caution if using the pedestal cup for reconstruction of a peri-acetabular tumour resection.

Cite this article: Bone Joint J 2014;96-B:1706–12.

Pelvis metastasis from primary choroidal melanoma: a case report

The patient, a 16-year-old girl, was admitted to our hospital with complaints of right hip pain and claudication. Her past medical history indicated that 2 years earlier she had undergone enucleation of her left eye for a primary choroidal melanoma. Imaging studies revealed a osteolytic destruction with soft tissue mass involving the right hemipelvis (zone I–II). Single-photon emission computed tomography (SPECT) and positron emission tomography–computed tomography (PET–CT) showed no other sites of metastases. Consequently, the patient underwent hemipelvic prosthesis reconstruction after tumor resection. Postoperative pathological diagnosis was metastatic malignant melanoma. Thirty months after treatment, imaging studies indicated no evidence of recurrence, and functional recovery was excellent. To our knowledge, the literature does not reveal any previously reported cases of ocular choroidal melanoma that metastasized to pelvis, meanwhile was carried out hemipelvic prosthesis reconstruction after pelvic tumor resection.

Internal hemipelvectomy with reconstruction for primary pelvic neoplasm: a systematic review

BACKGROUND

Hemipelvectomy is a major operation with significant risks including infection, prosthesis failure and fracture. This systematic review was designed to review the functional outcomes, oncologic outcomes and complications in patients who received internal hemipelvectomy and pelvic reconstruction for primary pelvic tumour.

METHODS

Searches on MEDLINE, the Cochrane Library, Embase and Google Scholar were performed to locate studies involving patients receiving internal hemipelvectomy and pelvic reconstruction using a prosthesis, implant or bone graft. All studies were either prospective or retrospective observational studies published in English.

RESULTS

This systematic review included 12 studies from 1990 to 2011 involving 217 patients from 5 to 77 years of age who had received follow-up for a period from 3 weeks to 15 years. Among the 12 studies, the mortality rate, disease-free rate and incidence of local recurrence were 10-69.2, 23.1-90.0 and 9.1-41.7%, respectively. The post-operative Musculoskeletal Tumor Society (MSTS) functional score ranged from 50 to 70 in the more recent studies. Compared with prostheses and other implants, patients who received allografts had the highest post-operative function, as shown by their MSTS scores, but also had a greater incidence of post-operative infection. On the other hand, the prosthesis group was associated with the highest percentage of fracture and dislocations, as well as other significant complications.

CONCLUSION

This comprehensive review provided informative details regarding the goals, outcomes and complications associated with this procedure and underscored the need for further investigation into the various surgical approaches currently available.

The use of extracorporeally irradiated autografts in pelvic reconstruction following tumour resection

The aim of this study was to evaluate the functional and oncological outcome of extracorporeally irradiated autografts used to reconstruct the pelvis after a P1/2 internal hemipelvectomy.

The study included 18 patients with a primary malignant bone tumour of the pelvis. There were 13 males and five females with a mean age of 24.8 years (8 to 62). Of these, seven had an osteogenic sarcoma, six a Ewing’s sarcoma, and five a chondrosarcoma. At a mean follow-up of 51.6 months (4 to 185), nine patients had died with metastatic disease while nine were free from disease. Local recurrence occurred in three patients all of whom eventually died of their disease. Deep infection occurred in three patients and required removal of their graft in two while the third underwent a hindquarter amputation for extensive flap necrosis.

The mean Musculoskeletal Tumor Society functional score of the 16 patients who could be followed-up for at least 12 months was 77% (50 to 90). Those 15 patients who completed the Toronto Extremity Salvage Score questionnaire had a mean score of 71% (53 to 85).

Extracorporeal irradiation and re-implantation of bone is a valid method of reconstruction after an internal hemipelvectomy. It has an acceptable morbidity and a functional outcome that compares favourably with other available reconstructive techniques.

Cite this article: Bone Joint J 2014;96-B:1404–10

Reconstruction of the hemipelvis with a modular prosthesis after resection of a primary malignant peri-acetabular tumour involving the sacroiliac joint

We report our early experience with the use of a new prosthesis, the Modular Hemipelvic Prosthesis II, for reconstruction of the hemipelvis after resection of a primary malignant peri-acetabular tumour involving the sacroiliac joint.

We retrospectively reviewed the outcome of 17 patients who had undergone resection of a pelvic tumour and reconstruction with this prosthesis between July 2002 and July 2010.

One patient had a type I+II+III+IV resection (ilium + peri-acetabulum + pubis/ischium + sacrum) and 16 had a type I+II+IV resection (ilium + acetabulum + sacrum). The outcome was assessed at a mean follow-up of 33 months (15 to 59). One patient was alive with disease, 11 were alive without disease and five had died of disease. The overall five-year survival rate was 62.4%. Six patients had a local recurrence. The mean Musculoskeletal Tumour Society score was 58% (33 to 77). Deep infection occurred in two patients, problems with wound healing in five and dislocation in one.

For patients with a primary malignant peri-acetabular sarcoma involving the sacroiliac joint, we believe that this new prosthesis is a viable option for reconstruction of the bony defect left following resection of the tumour. It results in a satisfactory functional outcome with an acceptable rate of complications.

Cite this article: Bone Joint J 2014;96-B:399–405.

Long-term results of reconstruction with pelvic allografts after wide resection of pelvic sarcomas

Reconstruction after the resection of a pelvic tumor is a challenging procedure in orthopedic oncology. The main advantage of allograft reconstruction is restoration of the bony architecture of the complex pelvic region. However, high complication rates such as infection and allograft resorption had been reported in the literature. In this study, we aimed to retrospectively review nine patients treated with pelvic resection and structural pelvic allograft reconstruction. Functional results, complications, and survival of the patients and the allografts were evaluated. At a mean follow-up of 79 months, three patients were dead. Major complications were detected in eight of the nine patients. Infection (four of the nine patients) and allograft resorption (three of the nine patients) were the most common causes of failure. The cumulative survival of the patients was 66.7 percent at 70 months. However, allograft survival was only 26.7 percent at 60 months. Mean MSTS score was 69. In conclusion, we suggest that other reconstruction options should be preferred after pelvic resections because of the high complication rates associated with massive allograft reconstruction.

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.

Composite reconstruction of the hip following resection of periacetabular tumors: middle-term outcome

The records of 18 patients with periacetabular tumors who underwent composite reconstruction of the hip following resection of periacetabular tumors were analyzed retrospectively. The mean follow-up period was 49.4 months (range, 28-100 months). During follow-up, 3 patients died and one had recurrence. Fifteen patients achieved favorable walking function; 8 had normal hip function and 7 had partial recovery of flexion function of the hip. The mean MSTS rating for hip function was 76.9%. Two patients had common peroneal nerve injury which was resolved in one of them. Middle-term follow-up showed that composite reconstruction of the hip following resection of periacetabular tumors can effectively remove tumors and provide favorable hip function for these patients. This approach is simple and less costly, and can be widely used.

Finite element analysis of the pelvis after modular hemipelvic endoprosthesis reconstruction

PURPOSE

The aim of this study was to investigate the biomechanics of the pelvis reconstructed with a modular hemipelvic prosthesis using finite element (FE) analysis.

METHODS

A three-dimensional FE model of the postoperative pelvis was developed and input into the Abaqus FEA software version 6.7.1. Mesh refinement tests were then performed and a force of 500 N was applied at the lamina terminalis of the fifth lumbar vertebra along the longitudinal axis of the normal pelvis and the postoperative pelvis for three positions: sitting, standing on two feet, and standing on the foot of the affected side. Stress distribution analysis was performed between the normal pelvis and postoperative pelvis at these three static positions.

RESULTS

In the normal pelvis, stress distribution was concentrated on the superior area of the acetabulum, arcuate line, sacroiliac joint, sacral midline and, in particular, the superior area of the greater sciatic notch. In the affected postoperative hemipelvis, stress distribution was concentrated on the proximal area of the pubic plate, the top of the acetabular cup, the connection between the CS-fixator and acetabular cup and the fixation between the prosthesis and sacroiliac joint.

CONCLUSIONS

Stress distribution of the postoperative pelvis was similar to the normal pelvis at three different static positions. Reconstruction with a modular hemipelvic prosthesis yielded good biomechanical characteristics.

Poor long-term clinical results of saddle prosthesis after resection of periacetabular tumors

BACKGROUND

The saddle prosthesis originally was developed to reconstruct large acetabular defects in revision hip arthroplasty and was used primarily for hip reconstruction after periacetabular tumor resections. The long-term survival of these reconstructions is unclear.

QUESTIONS/PURPOSE

We therefore examined the long-term function, complications, and survival in patients treated with saddle prostheses after periacetabular tumor resection.

PATIENTS AND METHODS

Between 1987 and 2003 we treated 17 patients with a saddle prosthesis after periacetabular tumor resection (12 chondrosarcomas, three osteosarcomas, one malignant fibrous histiocytoma, one metastasis). During followup, 11 patients died, resulting in a median overall survival of 49 months (95% CI, 30-68 months). The remaining six patients were alive without disease (mean followup, 12.1 years; range, 8.3-16.8 years). In one patient the saddle prosthesis was removed after 3 months owing to dislocation and infection. We obtained SF-36 questionnaires, Toronto Extremity Salvage Scores (TESS), and Musculoskeletal Tumor Society (MSTS) scores.

RESULTS

Thirteen of 17 patients used walking assists for mobilization at last followup: eight patients required two crutches, five needed one crutch, and one did not use any walking aids. The other three patients were not able to mobilize independently and only made bed to chair transfers. The mean hip flexion in the six surviving patients was 60° (range, 40°-100°) at last followup. Local complications were seen in 14 of the 17 patients: nine wound infections, seven dislocations, and two leg-length discrepancies requiring additional surgery. In the five surviving patients with their index prosthesis still in situ, the mean MSTS score at long-term followup was 47% (range, 20%-77%), the mean TESS score was 53% (range, 41%-67%), and the mean composite SF-36 physical and mental component summaries were 43.9 and 50.6, respectively.

CONCLUSION

Reconstruction with saddle prostheses after periacetabular tumor surgery has a high risk of complications and poor long-term function with limited hip flexion; therefore, we no longer use the saddle prosthesis for reconstruction after periacetabular tumor resections.

Results of surgical resection in pediatric pelvic tumors

Thirty nonmetastatic patients with malignant tumors of the pelvis underwent surgical resection between November 2000 and December 2009. The diagnosis included Ewing's sarcoma (22), osteogenic sarcoma (four), chondrosarcoma (two), and synovial sarcoma (two). Eighteen resections included the acetabulum and 12 did not. Twenty-seven patients were available for follow-up. Follow-up ranged from 4 to 138 months (mean 43 months). Nineteen patients are currently alive. There were two local recurrences. The overall survival was 68% at 5 years. The Musculoskeletal Tumor Society Score ranged from 22 to 29. Surgery provides good local control and oncologic outcomes with acceptable function in these patients.

Pelvic massive allograft reconstruction after bone tumour resection

PURPOSE

The purpose of this report was to retrospectively review a series treated with pelvic tumour resection and massive allograft reconstruction, and determine survival of patients and implants, functional results and morbidity of surgical technique.

METHODS

From 1999, 33 patients underwent pelvic tumour resection and massive allograft reconstruction. The mean age was 40 years (range, 14-72) and 29 patients had a primary malignant tumour. The resection involved the acetabular area in all but three patients.

RESULTS

At a median follow-up of 33 months (range, two-143) four patients had local recurrence. The morbidity was high: five deep infections (15 %), requiring two allograft removal, six hip dislocations (18 %), eight sciatic nerve palsy (24 %), persistent in six cases, and two loosening of the acetabular component. Implant survival was 87.3 % at last follow up. The cumulative overall patient's survival was 41.5 % at five and ten years. The average MSTS functional score was 70 % (range, 54-100 %) when the acetabulum was preserved while it was 61 % (30-100 %) in patients with acetabular resection.

CONCLUSION

In conclusion, pelvic allografts represent a valid option for reconstruction after resection of pelvic tumours but due to the associated morbidity, patients should be carefully selected.

Reconstruction of type II+III pelvic resection with a modular hemipelvic endoprosthesis: a finite element analysis study

OBJECTIVE

To conduct a biomechanical study of the whole reconstructed pelvic ring using a modular hemipelvic endoprosthesis.

METHODS

A subject-specific finite-element (FE) model of the whole pelvic ring, including the pelvis, sacrum and main ligaments, was constructed. Type II+III pelvic resection was simulated on the FE model. Then a three-dimensional model of a reconstructed pelvic ring with a modular hemipelvic endoprosthesis was developed, and FE analysis performed to compare the stresses along the bilateral arcuate lines of the reconstructed and normal pelvis in the bipedal standing position. Comparison between bilateral stress distributions along the sciatic notch was also performed. The characteristics of load transmission within the endoprosthesis were also studied.

RESULTS

No significant difference in the stresses along the bilateral arcuate lines was observed between the reconstructed and normal pelvis. The stress distribution on the prosthesis along the sciatic notch paths was significantly greater than that on the unaffected side in the same position. The peak stress of the implant on the S1 vertebral body was 182.9 MPa under a load of 600N. Study of load transfer on the implant showed that the posterior side of the column between the point of iliac fixation and the acetabulum was subject to the greatest stress.

CONCLUSION

This FE study showed that a modular hemipelvic endoprosthesis can restore load transfer between the sacrum and acetabulum on simple standing. Future implant design should aim to decrease the stress concentration and make the biomechanical performance more balanced.

Primary tumor of the periacetabular region: resection and reconstruction using a segmental ipsilateral femur autograft

INTRODUCTION

Bone reconstruction, after periacetabular tumour removal, is a complex procedure that carries a high morbidity rate and can result in poor clinical outcomes. Among the available options, the Puget pelvic resection-reconstruction procedure uses an autograft from the ipsilateral proximal femur to restore the anatomical and mechanical continuity of the pelvic ring before inserting an acetabular implant. HYPOTHESIS AND GOALS: This reconstruction technique satisfactorily restores the pelvic anatomy such that functional results and morbidity are comparable to alternative reconstruction techniques.

PATIENTS AND METHODS

This was a retrospective study of 10 patients with an average age of 38.2 years (range 19 to 75) at the surgical procedure (performed between 1986 and 2007). There were five chondrosarcomas, three Ewing tumours, one plasmacytoma and one giant cell tumour. The position of the hip centre of rotation after reconstruction and autograft integration were evaluated on radiographs. Functional results were evaluated through the Musculoskeletal Tumor Society (MSTS) score and the Postel and Merle d'Aubigné (PMA) score.

RESULTS

At the time of review, one patient was lost to follow-up and four had died. On radiographs, the hip centre of rotation after reconstruction was higher by a median value of 15 mm (range 5 to 35) and more lateral by a median value of 6mm (range -5 to 15). Upon evaluation of radiographs at a median time of 40 months (range 6 to 252 months), the autograft was completely integrated in five patients and partially integrated in three patients (two patients had a local recurrence). There were no cases of autograft fracture or non-union at the junctions of the graft. The median MSTS score was 25 out of 30 (range 20 to 29), or 83% (range 67 to 97%) at the median clinical follow-up of 82 months (range 49 to 264). The median PMA score was 13 out of 18 (range 12 to 18). All living patients were walking without assistance. Five patients required nine surgical revisions. Seven were attributed directly or indirectly to local recurrence; one revision was performed because of instability and one because of early acetabular loosening at 9 months.

CONCLUSION

This challenging procedure provides satisfactory mechanical and anatomical results, while restoring hip anatomy and function. The primary cause of failure in this series was local recurrence of the tumour, which highlights the need to carefully select the indications and optimize the surgical tumour resection.

Clinical and functional outcomes of the saddle prosthesis

BACKGROUND

The implantation of a saddle prosthesis after resection of a pelvic tumor has been proposed as a simple method of reconstruction that provides good stability and reduces the surgical time, thus limits the onset of intraoperative complications. There are no studies in the literature of patients evaluated using gait analysis after being implanted with a saddle prosthesis. The present study is a retrospective case review aimed at illustrating long-term clinical and functional findings in tumor patients reconstructed with a saddle prosthesis.

MATERIALS AND METHODS

A series of 15 patients who received pelvic reconstruction with a saddle prosthesis were retrospectively reviewed in terms of clinical, radiographic, and functional evaluations. Two patients were additionally assessed by gait analysis.

RESULTS

Long-term functional follow-up was achieved in only 6 patients, and ranged from 97 to 167 months. Function was found to be rather impaired, as a mean of only 57 % of normal activity was restored. Gait analysis demonstrated that the implant had poor biomechanics, as characterized by very limited hip motion.

CONCLUSIONS

Though the saddle prosthesis was proposed as advance in tumor-related pelvic surgery, the present study indicates that it yields unsatisfactory clinical and functional results due to both clinical complications and the poor biomechanics of the device. The use of a saddle prosthesis in tumor surgery did not provide satisfactory results in long-term follow-up. It is no longer implanted at our institute, and is currently considered a "salvage technique."

The anatomy of proximal femoral autografts for pelvic reconstruction: a cadaveric study

PURPOSE

One important reconstruction procedure following pelvic tumor resection is ipsilateral femoral autograft reconstruction in which the autograft is transposed onto the defect and a conventional total hip replacement is implanted in the autograft. The purpose of this study is to provide anatomical evidence for this reconstruction by measurement of proximal femoral autografts.

METHODS

The anatomical study of proximal femoral autografts was performed on thirteen fresh-frozen Chinese male cadavers. Four parameters were measured and included the diameter of the femoral head (DFH), the distance from the apex of the greater trochanter perpendicular to the medial cortex edge of the femoral neck (DAM), the length between the apex of the femoral head and the midpoint of osteotomy line under the lesser trochanter (LAM), and the width of the greater trochanter from anterior to posterior (WG). The correlation between height and each of the various parameters was analyzed using the Spearman's correlation.

RESULTS

The median (first and third quartile) values of the measurements for the above mentioned parameters were 49 mm (48-52.7 mm), 58.5 mm (54.5-60.9 mm), 102 mm (96-105.2 mm) and 48 mm (46.5-51 mm), respectively. There was a positive correlation between height and each of these four parameters (P < 0.05).

CONCLUSIONS

The proximal femoral autograft reconstruction may be a good option after resection of a pelvic tumor because of the provision of biological reconstruction. However, an individual preoperative plan should be carefully performed following evaluating the size of the bone defect after tumor resection and height and width of the remaining greater trochanter prior to conventional hip replacement.

Transperitoneal removal of an intrapelvic acetabular component after total hip replacement and salvage of a destroyed acetabulum

Intrapelvic migration of the acetabular component of a total hip replacement, with severe acetabular destruction making reconstruction impossible, is very rare. We present a patient in whom the component was removed using a laparotomy and a transperitoneal approach with subsequent salvage using a saddle prosthesis and a total femoral replacement.

Ice-cream cone reconstruction of the pelvis: a new type of pelvic replacement

Endoprosthetic replacement of the pelvis is one of the most challenging types of limb-salvage surgery, with a high rate of complications. In an attempt to reduce this and build greater versatility into the reconstruction process, a new type of pelvic endoprosthesis was developed in 2003, based on the old McKee-Farrar prosthesis. This study reviews the outcomes in 27 patients who had an ice-cream cone pelvic prosthesis inserted at two different specialist bone tumour centres in the United Kingdom over the past six years. The indications for treatment included primary bone tumours in 19 patients and metastatic disease in two, and six implants were inserted following failure of a previous pelvic reconstruction. Most of the patients had a P2+P3 resection as classified by Enneking, and most had resection of the ilium above the sciatic notch. The mean age of the patients at operation was 49 years (13 to 81). Complications occurred in ten patients (37.0%), of which dislocation was the most common, affecting four patients (14.8%). A total of three patients (11.1%) developed a deep infection around the prosthesis but all were successfully controlled by early intervention and two patients (7.4%) developed a local recurrence, at the same time as widespread metastases appeared. In one patient the prosthesis was removed for severe pain.

This method of treatment is still associated with high morbidity, but early results are promising. Complications are diminishing with increasing experience.

Hemipelvectomy- only a salvage therapy?

After the first hemipelvectomy in 1891 significant advances have been made in the fields of preoperative diagnosis, surgical technique and adjuvant treatment in patients with pelvic tumors. The challenging surgical removal of these rare malignant bone or soft tissue tumors accompanied by interdisciplinary therapy is mostly the only chance of cure, but bares the risk of intensive bleeding and infection. The reconstruction after hemipelvectomy is of importance for the later outcome and quality of life for the patient. Here, plastic surgery with microvascular free flaps or local rotational flaps improved the reconstruction and reduced infection rates. Average local recurrence rates of 14% demonstrate good surgical results, but 5 year survival rates of only 50% are described for some tumor entities, showing the importance of a multimodal collaboration. On a basis of a selective literature review the history, indications, treatment options and outcome of hemipelvectomies are presented.

Outcome after pelvic sarcoma resection and reconstruction with a modular hemipelvic prostheses

PURPOSE

The aim of this study was to evaluate the early clinical outcome of reconstruction with modular hemipelvic prostheses after pelvic sarcoma resection.

METHODS

We retrospectively reviewed eight patients between 2004 and 2007 who had periacetabular resections and reconstruction with a modular hemipelvic prosthetic system for pelvic sarcoma with a mean follow-up of 27 (range,10~54) months. Oncology outcome was assessed with survival rate, local recurrence rate, International Society of Limb Salvage (ISOLS) score and complications. Two patients had types I and II (periacetabular and ilium) pelvic resections, three had types II and III (periacetabular and pubis) pelvic resections and three had type I , II and III (ilium, periacetabular and pubis) pelvic resections. Nobody received chemotherapy or radiotherapy.

RESULTS

Five patients were free of disease; three patients died of disease. The overall survival rate was 62.5%. None had local recurrence, and 37.5% had metastasis. The mean ISOLS score was 19.5. No one had deep infection or dislocation.

CONCLUSIONS

Reconstruction with a modular hemipelvic prosthetic system after periacetabular resection is a promising method because of the acceptable complication rate and satisfactory functional outcome.

Infection following Bone Tumor Resection and Reconstruction with Tumoral Prostheses: A Literature Review

Bone resection is the choice treatment of malignant bone tumors. Tumor prosthesis is one of the most common solutions of reconstruction following resection of bone tumor located to the metaphysis of long bones. Periprosthetic infections are a frequent complication of limb-salvage surgery which is largely due to prolonged and repeated surgeries, as well as to the immunocompromised condition of these patients due to neoplastic treatment. Furthermore, the large exposure of tissues during this type of surgery and the dissection across vascular distributions also contributes to the high risk of infection. The authors reviewed the literature discussing the incidence of infections of tumor prosthesis implanted following resection of bone tumors, taking into account the different sites of implantation. In the English literature, the highest risk of infection which led to limb amputation was observed after proximal tibia resection and this difference was considered to be due to the poor condition of soft tissue and also after pelvic resection due to huge dead space after sarcoma resection not filled by implant. Independent of the location, the management of infected prosthesis is similar. That is, after one or more attempts at debridement and antibiotic therapy, it consists of implant removal and insertion of a new implant in a one- or two-stage procedure, with a decreased risk of failure with the two-stage procedure.

Computer assisted pelvic tumor resection and reconstruction with a custom-made prosthesis using an innovative adaptation and its validation

Computer aided musculoskeletal tumor surgery is a novel concept. Ideally, computer navigation enables the integration of preoperative information concerning tumor extent and regional anatomy to facilitate execution of a surgical resection. Accurate resection helps oncological clearance and facilitates precise fitting of a custom prosthesis. We adapted a commercially available computer navigation platform for spine, and used it to plan and execute pelvic bone resection and custom pelvic prosthetic reconstruction in a patient with a metastatic tumor affecting the acetabulum. The surgery was simulated and validated using a plaster bone model based on the patient's preoperative CT data, before performing the procedure on the patient.

The Friedman-Eilber resection arthroplasty of the pelvis

It has been argued that internal hemipelvectomy without reconstruction of the pelvic ring leads to poor ambulation and inferior patient acceptance. To determine the accuracy of this contention, we posed the following questions: First, how effectively does a typical patient ambulate following this procedure? Second, what is the typical functional capacity of a patient following internal hemipelvectomy? In the spring of 2006, we obtained video documentation of eight patients who had undergone resection arthroplasty of the hemipelvis seen in our clinic during routine clinical followup. The minimum followup in 2006 was 1.1 years (mean, 8.2 years; range, 1.1-22.7 years); at the time of last followup in 2008 the minimum followup was 2.9 years (mean, 9.8 years; range, 2.9-24.5 years). At last followup seven of the eight patients were without pain, and were able to walk without supports. The remaining patient used narcotic medication and a cane or crutch only occasionally. The mean MSTS score at the time of most recent followup was 73.3% of normal (range 53.3-80.0%; mean raw score was 22.0; range 16-24). All eight patients ultimately returned to gainful employment. These observations demonstrate independent painless ambulation and acceptable function is possible following resection arthroplasty of the hemipelvis.

LEVEL OF EVIDENCE

Level IV, case series. See Guidelines for Authors for a complete description of levels of evidence.

Periacetabular reconstruction with a new endoprosthesis

Reconstruction of the Type II pelvic resection is challenging. Currently available reconstructive options have inherent problems including graft and implant failure, pain, poor function, and high major complication rates. The periacetabular reconstruction (PAR) endoprosthesis was designed to be secured with internal fixation and bone cement to the remaining ilium and support a reconstructed acetabulum. This construct potentially avoids the complications of graft or hardware failure, while maintaining early mobilization, comfort, limb lengths, and function. We retrospectively reviewed 25 patients who underwent Type II pelvic resection and reconstruction with the PAR endoprosthesis, analyzing function, complications, and survivorship. The minimum followup was 13 months (mean, 29.4 months; range, 13 to 108 months). We compared the PAR data with the literature for the Mark II saddle endoprosthesis. The PAR's average MSTS score was 20.8 (67%), major complications occurred in 14 (56%), and implant survivorship was 84% at 2 years and 60% at 5 years. The rate of failure at the ilium-saddle interface was lower and implant survivorship higher than those in the published literature for the Mark II saddle. We recommend use of the PAR endoprosthesis for reconstruction of large defects following Type II pelvic resection. The modified saddle design provides greater inherent stability, allowing for faster rehabilitation and improved longevity without increased complications and is an improvement over the currently available saddle prostheses.

LEVEL OF EVIDENCE

Level III, retrospective case series. See Guidelines for Authors for a complete description of levels of evidence.

Evaluation of blood loss during limb salvage surgery for pelvic tumours

As a large amount of blood loss is sometimes encountered in limb salvage procedures for pelvic tumours, it is essential to identify risk factors predicting the possibility of extensive haemorrhage. We retrospectively reviewed 137 patients who underwent pelvic tumour resections. Patients with an estimated blood loss greater than 3,000 ml were classified as having a large amount of blood loss. Sixty-one (44.53%) patients had blood loss greater than 3,000 ml. Tumours involving the acetabulum or sacrum, tumour volume greater than 400 cm(3), aorta occlusion, resection method, reconstruction and operative time were all associated with a large amount of blood loss. Pelvic tumours involving the acetabulum or sacrum (odds ratio: 4.837), tumour volume greater than 400 cm(3) (odds ratio: 3.005) and planned operation time of more than 200 min (odds ratio: 3.784) independently predicted a large amount of blood loss. Pelvic tumours with these characteristics were likely to have a large amount of blood loss during surgery.

Peri-acetabular resection and endoprosthetic reconstruction for tumours of the acetabulum

We treated 98 patients with peri-acetabular tumours by resection and reconstruction with a custom-made pelvic endoprosthesis. The overall survival of the patients was 67% at five years, 54% at ten years and 51% at 30 years. One or more complications occurred in 58.1% of patients (54), of which infection was the most common, affecting 30% (28 patients). The rate of local recurrence was 31% (29 patients) after a mean follow-up of 71 months (11 to 147). Dislocation occurred in 20% of patients (19). Before 1996 the rate was 40.5% (17 patients) but this was reduced to 3.9% (two patients) with the introduction of a larger femoral head. There were six cases of palsy of the femoral nerve with recovery in only two. Revision or excision arthroplasty was performed in 23.7% of patients (22), principally for uncontrolled infection or aseptic loosening. Higher rates of death, infection and revision occurred in men.

This method of treatment is still associated with high morbidity. Patients should be carefully selected and informed of this pre-operatively.

Reconstruction of type II pelvic resection with a new peri-acetabular reconstruction endoprosthesis

We report our early experience with a new peri-acetabular reconstruction endoprosthesis used for pelvic reconstruction after tumour resection. The outcome of 21 patients who underwent limb salvage following type II pelvic resection and reconstruction using the peri-acetabular reconstruction prosthesis between 2000 and 2006 was retrospectively reviewed. This prosthesis was designed to use the remaining part of the ilium to support a horizontally placed acetabular component secured with internal fixation and bone cement. Into this device a constrained acetabular liner is positioned which is articulates with a conventional femoral component to which a modular extension and modular head are attached. The mean follow-up was 20.5 months (1 to 77). The most common complications were deep infection, superficial wound infections, and dislocation. The mean musculoskeletal tumor society functional outcome score for the survivors was 20.1(11 to 27).

We recommend the use of the peri-acetabular reconstruction prosthesis for reconstruction of large defects after type II pelvic resection, as this design has a greater inherent stability over other available prostheses.

Reconstruction with modular hemipelvic prostheses for periacetabular tumor

Periacetabular resections for primary bone sarcoma and metastatic disease require reconstruction to restore weight-bearing along anatomic axes. We designed a modular hemipelvic prosthetic system to reconstruct the pelvis and evaluated the early clinical outcome of the prosthesis using 3-year survival rate, local recurrence rate, Musculoskeletal Tumor Society (MSTS) 93 function score, and complications. We retrospectively reviewed 28 patients who had pelvic tumor resections and reconstructions using the new hemipelvic prostheses between 2001 and 2005. Sixteen (57.1%) patients had Types II and III (periacetabular and pubis) pelvic resections, seven had Types I and II (periacetabular and ilium) pelvic resections, and five had Type II (periacetabular) pelvic resection. Six patients with osteosarcoma had chemotherapy. None received radiation therapy. Patient survival status, function, and complications were evaluated at a mean followup of 30 months (range, 10-59 months). Fifteen patients were free of disease, eight patients died of disease, and five patients were alive with disease. The overall survival rate was 67.1% at 3 years. Twenty-five percent had local recurrence and 21% had metastasis. The mean MSTS 93 score was 60. Deep infection occurred in four patients; dislocation occurred in one patient. The results are encouraging because of the acceptable complication rate and satisfactory functional outcome.