Early Results of Acetabular Reconstruction After Wide Periacetabular Oncologic Resection

Incidence of avascular necrosis of native femur following hip transposition surgery for periacetabular malignancies: a single-centre experience

BACKGROUND

Hip transposition surgery after surgical resection of large pelvic tumours is a well-established alternate to endoprosthetic reconstruction. The major goals of surgery are to ensure adequate resection margins with limb salvation, albeit with acceptable levels of morbidity. While surveillance is aimed at diagnosing local recurrence or distant metastasis primarily, other complications may occasionally be seen.The aim of this study was to assess incidence of avascular necrosis (AVN) in the preserved native femoral heads after hip transposition surgery for periacetabular malignancies, also known as hanging hip surgery.

PATIENTS AND METHODS

Patient records and follow-up imaging of 22 patients who had undergone hanging hip surgery from 1999 to 2020 were retrospectively analysed to assess for any probable causes of AVN.

RESULTS

Of the 22 patients, 5 (22.7%) had developed AVN on follow-up with a mean time of onset of about 10.5 months from surgery (5 months-2 years). A review of the patient demographics, surgical notes, preoperative management did not offer any clues as to the cause of AVN in these patients. Osteopenia was the most common radiological finding (59%) in most patients, but this also did not herald AVN onset.

CONCLUSIONS

The theory that loss of major vascular supply to the femoral head from capsular disruption during hip transposition surgery would lead to AVN in most patients did not hold true as AVN occurred in a small number of patients.

Clinical outcomes in patients with neurological disorders following periacetabular tumor removal and endoprosthetic reconstruction of the hemipelvis

Background

Surgical treatment of musculoskeletal tumors in the periacetabular region present extremely difficult due to the complex anatomy and need for reconstruction. Orthopedic surgeons face more difficulties in patients with neurological conditions, which can cause increased muscle tone, an elevated risk of fractures, and compromised bone quality. There is limited evidence regarding endoprosthetic reconstruction for periacetabular tumors in individuals with neurological disorders.

Methods

We conducted a single-center retrospective study to examine the outcomes of patients with preexisting neurological conditions who underwent surgery to remove periacetabular tumors and who underwent endoprosthesis reconstruction. Clinical presentation, detailed neurological conditions, complications, and functional outcomes were studied.

Results

Sixteen out of the 838 patients were identified (1.91%), with a mean follow-up time of 33 months. The primary neurological conditions encompassed Parkinson's disease, Alzheimer's disease, dementia, and cerebral ischemic stroke. Every patient was diagnosed with periacetabular lesions that were either primary or oligometastatic. They underwent tumor resection and subsequently received endoprosthetic reconstruction of the hemipelvis. Three patients developed metastasis lesions later, and two patients experienced tumor recurrence. Five cases experienced hip dislocation-one with periprosthetic fracture and one with surgical site infection. The position of the prosthetic rotating center was not correlated with dislocation. The reoperation rate was 31.25%. The cohort of patients all presented with more extended hospital stays and rehabilitation. In 3 patients, the general functional score was good, while in 6 patients, it was fair; in 7 patients, it was regarded as poor. The average MSTS93 score was 49.71%.

Conclusion

Endoprosthetic reconstruction after periacetabular tumor resection is an effective way to eliminate tumors and salvage limbs. However, this group of patients has an increased likelihood of secondary surgery, complications, extended hospital stay, and no significant improvement in functional outcomes. Despite the diverse nature of the cohort, it is recommended to consider enhanced soft tissue reconstruction, supervised functional recovery and rehabilitation training.

Midterm outcomes of total hip arthroplasty after internal hemipelvectomy and iliofemoral arthrodesis

BACKGROUND AND OBJECTIVES

Recent studies have reported acceptable outcomes after arthrodesis takedown and conversion to total hip arthroplasty (THA); however, there are no reports on outcomes after oncologic resection, which are inherently complex and may portend poorer outcomes. The purpose of this study was to examine the surgical and functional outcomes of patients who underwent prior hemipelvectomy for tumor resection and were later converted to THA.

METHODS

All patients who had prior iliofemoral arthrodesis after oncologic resection that were later converted to THA at a single institution were examined. Charts were reviewed for demographic information, operative information, functional outcomes, and complications/reoperations.

RESULTS

All three patients in this study were males who underwent internal hemipelvectomies for chondrosarcoma. Patients were converted to THA at a mean of 26 years after arthrodesis. Mean follow-up after conversion to THA was 7.4 years. During this follow-up period, two of the three patients required revision surgery. At last follow-up, the mean Harris Hip Score was 81 and the mean Mayo Hip Score was 67, and all patients were ambulatory without significant pain.

CONCLUSIONS

Overall, patients who undergo iliofemoral arthrodesis after oncologic hemipelvectomy and are later converted to THA can expect to have a reasonable outcome, despite a high rate of complications and revision surgery.

Hip Transposition Can Provide Early Walking Function After Periacetabular Tumor Resection: A Multicenter Study

BACKGROUND

Reconstruction after periacetabular bone tumor resection involves important tradeoffs; large bone grafts or endoprostheses are reported to offer fair walking function in general but can be technically demanding and carry a high risk of severe complications. Conversely, hip transposition avoids implant-related risks, but stability and functional return may be less consistent. Fewer studies are available on hip transposition, which is also appealing in more resource-constrained environments, and little is known about the time course from surgery to functional return after hip transposition.

QUESTIONS/PURPOSES

(1) What is the time course of recovery of walking function after hip transposition, especially in the first 6 months? (2) What factors are associated with a greater likelihood of early functional recovery? (3) Is early (2-month) functional recovery associated with a greater likelihood of walking ability and higher Musculoskeletal Tumor Society (MSTS) scores?

METHODS

Between 2009 and 2019, six tertiary care centers in Japan treated 48 patients with internal hemipelvectomy for malignant tumors. During that time, the preferred reconstructive approach was hip transposition, and 92% (44 of 48) of our patients were treated with this procedure. Among them, 86% (38 of 44) had follow-up of at least 6 months, had no local recurrence during that time, and were included in our retrospective study. We chose 6 months as the minimum follow-up duration because the endpoints in this study pertained to early recovery rather than reconstructive durability. Hip transposition involved moving the proximal end of the femur (femoral head, resection end of the trochanteric area, and spacers such as prostheses) upward to the underside of the resected ilium or the lateral side of the sacrum if sacroiliac joint resection was performed. The end of the proximal femur was stabilized to the remaining ilium or sacrum using polyethylene tape, polyethylene terephthalate mesh, an iliotibial tract graft, or an external fixator, according to the surgeon's preference. The median age at surgery was 46 years (range 9 to 76 years), there were 23 women and 15 men, and the median follow-up duration was 17 months (range 6 to 110 months). The postoperative time course of functional recovery was assessed with a record review, the timing of functional milestones was identified (wheelchair, walker, bilateral crutches, single crutch or cane, and walking without an aid), and the MSTS score at the final follow-up was assessed. Additionally, demographic and surgical factors were reviewed, and their association with short-term functional recovery and the final functional outcome was analyzed.

RESULTS

Patients started using a walker at median postoperative day (POD) 20 (IQR 14 to 36) and with bilateral crutches at median POD 35 (IQR 20 to 57). At POD 60, which was the approximate median date of discharge, 76% (29 of 38) of patients were able to walk using bilateral crutches (the early recovery group) and 24% (nine of 38) of patients were not able to do so (the delayed recovery group). No baseline factors were different between the two groups. The early recovery group had a higher median MSTS score than the delayed recovery group: 57% (range 17% to 90%) versus 45% (13% to 57%) (p = 0.047). Moreover, more patients acquired better function (a single crutch or cane or more) in the early recovery group, with a median of 5 months (95% CI 4 to 11) than did those in the delayed recovery group (median not reached) (p = 0.0006). The HR was 15.2 (95% CI 2.5 to 93). Forty-two percent (16 of 38) underwent additional surgery for wound management.

CONCLUSION

It took patients a fair amount of time to recover walking function after hip transposition, and patients who could not walk on bilateral crutches at POD 60 seemed less likely to regain walking function and were likely to have lower MSTS scores thereafter. Wound-related complications were frequent. This method may be a realistic alternative for younger patients who have the strength for a long rehabilitation period or those who want to minimize prosthesis-related complications. Future studies with more patients are necessary to understand the risk factors associated with delayed recovery.Level of Evidence Level III, therapeutic study.

Porous tantalum acetabular cups for reconstructions after peri-acetabular resections of primary bone tumours

INTRODUCTION

Periacetabular reconstruction after resection of primary bone tumour is a very demanding procedure. They are frequently associated with scarce functional results and a high rate of complications. We report a series of patients with periacetabular resections for primary bone tumours and reconstruction with a porous tantalum (PT) acetabular cup (AC).

MATERIALS AND METHODS

27 patients (median age 30 years) were included, being affected by primary bone tumours of the pelvis and treated with peri-acetabular resection and reconstruction with a PT AC. The diagnoses were 13 osteosarcomas, 7 chondrosarcomas and 7 Ewing sarcomas. Function was assessed with the Harris Hip Score and complications were classified according to Zeifang.

RESULTS

The median follow-up was 70 months. 1 patient required removal of the PT AC because of implant associated infection 55 months after surgery. There was 1 hip dislocation and no case of aseptic loosening. At final follow-up, the median HHS was 81 points (range 48-92).

CONCLUSIONS

The used PT AC had good medium-term survival rates and good functional results. This technique is a viable reconstructive option after resections of periacetabular primary bone sarcomas.

Comparison of customized 3D-printed prosthesis and screw-rod-cage system reconstruction following resection of periacetabular tumors

Background and purpose

Various operative methods are used for reconstructing pelvic girdle after resection of primary malignant periacetabular tumor has been reported. The objective of this study was to evaluate the accuracy, effectiveness, and safety of customized three dimensional-printed prosthesis (3DP) in the reconstruction of bone defects compared with conventional reconstruction using the screw-rod-cage system.

Methods

A retrospective case–control analysis of 40 patients who underwent pelvic tumor resection and reconstruction with a customized 3D-printed prosthesis (3DP), or screw-rod-cage system (SRCS) between January 2010 and December 2019 was performed. The minimum follow-up time for patients alive was 2 years. Blood loss, operation time, complications, surgical margin, local recurrence, distant metastases, status at time of latest follow-up, MSTS-93 score, Harris hip score, and postoperative radiographic parameters were recorded. Moreover, overall survival, tumor-free survival, and prosthesis survival rates in both groups were compared.

Results

Customized 3DP reconstruction was performed in 15 patients, and SRCS reconstruction was done in 25 patients. The group of patients treated with customized 3DP reconstruction had significantly shorter operation time (323.7 ± 83.7 vs. 393.6 ± 98.8 min; P = 0.028) and more precise (all P < 0.05) radiographic reconstruction parameters than patients in the SRCS group. Fewer complications (P = 0.026), better MSTS score (P = 0.030), and better Harris hip score (P = 0.016) were achieved in the 3DP group. Furthermore, the survival rate of prosthesis was also significantly better in the 3DP group (P = 0.039). However, blood loss, surgical margin, local recurrence, distant metastases, and status at time of latest follow-up had no significant difference between two groups.

Conclusion

Compared with the screw-rod-cage system reconstruction, the customized 3D-printed prosthesis reconstruction is equally safe and effective, but it is more accurate and time-saving and is associated with fewer complications.

Long-term functional recovery in patients with custom-made 3D-printed anatomical pelvic prostheses following bone tumor excision

BACKGROUND

Anatomical custom-made prostheses make it possible to reconstruct complicated bone defects following excision of bone tumors, thanks to 3D-printed technology. To date, clinical measures have been used to report clinical-functional outcome and provide evidence for the effectiveness of this new surgical approach. However, there are no studies that quantified the achievable recovery during common activities by using instrumental clinical-functional evaluation in these patients.

RESEARCH QUESTION

What is the motor performance, functional outcome and quality of life in patients with custom-made 3D-printed pelvic prostheses following bone tumor?

METHODS

To analyze motor performance, six patients performed motion analysis during five motor activities at follow-up of 32 ± 18 months. Joint angles, ground reaction forces and joint moments of the operated and contralateral limbs were compared. On-off activity of lower-limb muscles were calculated from electromyography and compared to a healthy matched population. To analyze functional outcome and quality of life, differences in measured hip abductor strength between limbs were evaluated, as well as clinical-functional scores (Harris Hip Score, Barthel Index, Musculoskeletal Tumor Society score), and quality of life (SF-36 health survey).

RESULTS

We found only slight differences in joint kinematics when comparing operated and contralateral limb. The activity of gluteal muscles was normal, while hamstrings showed out-of-phase activities. Ground reaction forces and hip moments showed asymmetries between limbs, particularly in more demanding motor activities. We found a mean difference in hip abductor strength of 48 ± 82 N between limbs, good clinical-functional scores, and quality of life scores within normative.

SIGNIFICANCE

Our study showed optimal long-term results in functional recovery, mainly achieved through recovery of the gluteal function, although minor impairments were found, which may be considered for future improvement of this innovative surgery. The effect of a more loaded contralateral limb on internal loads and long-term performance of the implant remains unknown and deserves further investigation.

Computer-Aided Design and 3D Printing of Hemipelvic Endoprosthesis for Personalized Limb-Salvage Reconstruction after Periacetabular Tumor Resection

3D-printed hemipelvic endoprosthesis is an emerging solution for personalized limb-salvage reconstruction after periacetabular tumor resection. Further clinical studies are still required to report its surgical characteristics, outcomes, benefits and drawbacks. Sixteen consecutive patients underwent periacetabular tumor wide resection and pelvic reconstruction with a 3D-printed hemipelvic endoprosthesis from 2018 to 2021. The surgical characteristics and outcomes are described. The mean follow-up duration was 17.75 months (range, 6 to 46 months). Five patients underwent surgery for type I + II resection and reconstruction, seven for type II + III resection and reconstruction, three for type II resection and reconstruction, and one for type I + II + IV resection and reconstruction. The incidence of postoperative complication was 12.5% (2/16) for deep venous thrombosis (DVT), 12.5% (2/16) for pneumonia, and 12.5% (2/16) for would deep or superficial infection. During follow-up, two patients (12.5%) suffered hip dislocation and underwent revision surgery. CT demonstrated an obvious prosthetic porous structure–bone fusion after follow-up of at least 6 months. At the final follow-up, 12 lived with no evidence of disease while four lived with disease; no patients experienced pain; and 15 had independent ambulation, with a mean Musculoskeletal Tumor Society (MSTS) score of 85.8% (range, 26.7% to 100%). 3D-printed hemipelvic endoprosthesis facilitates wide resection of periacetabular tumor and limb-salvage reconstruction, thus resulting in good oncological and functional outcomes. The custom-made nature is able to well mimic the skeletal anatomy and microstructure and promote osseointegration. Perioperative complications and rehabilitation exercise still need to be stressed for this engineering technology-assisted major orthopedic surgery.

Feasibility and preliminary efficacy of tantalum components in the management of acetabular reconstruction following periacetabular oncologic resection in primary malignancies

Background

The aim of the study was to investigate the feasibility and preliminary efficacy of tantalum components utility in the reconstruction of acetabular defects following periacetabular oncologic resection of primary malignancies.

Methods

We prospectively collected a consecutive of 15 cases that were treated with tantalum components for acetabular reconstruction after periacetabular oncologic resection from January 2018 to December 2018. The cohort included 8 male and 7 female patients, with a mean age of 47.6 years (range, 33 to 67 years). Pathology types: chondrosarcoma (n = 9), malignant bone giant cell tumor (n = 3) and osteosarcoma (n = 3). Clinical outcomes, functional and radiographic results were recorded in detail for analysis.

Results

Patients received planned oncologic resection and tantalum components reconstruction without casualty; they were followed up with a mean of 39.7 months (35–45 months). The mean operation time was 4.0 h (3.0–6.0 h), and the mean blood loss was 1260 ml (800–2200 ml). Functional outcomes were assessed by MSTS-93 scale, with an average of 21.8 (12.0–26.0 scores), among which 3 cases were excellent, 11 were good and 1 was fair. The mean Harris Hip Score was 79.1scores (46.0–92.0 scores) at 1-year follow-up postoperatively. 3(3/15, 20.0%) cases experienced postoperative complications: 2 cases with hip dislocation received closed reduction under general anesthesia and were fixed with hip joint abduction braces for 6 weeks; one case had a superficial infection and received debridement with a delayed wound healing. Oncologic prognosis: one case relapsed at 8-month follow-up and received hemi-pelvic amputation; and another osteosarcoma patient experienced relapse with pulmonary metastasis and received further chemotherapy. No prosthetic loosening, displacement or fracture occurred during the follow-up period.

Conclusion

Preliminary results suggested that the use of tantalum components in the management of acetabular reconstruction following periacetabular oncologic resection provided reasonable improvement on functional outcomes and early stability of the prostheses. Porous tantalum components are conducive to bony ingrowth, which is a potential alternative to various existing reconstruction techniques to achieve better functional outcomes.

Periacetabular reconstruction following limb-salvage surgery for pelvic sarcomas

Limb-salvage surgery for pelvic sarcomas remains one of the most challenging surgical procedures for musculoskeletal oncologists. In the past several decades, various surgical techniques have been developed for periacetabular reconstruction following pelvic tumor resection. These methods include endoprosthetic reconstruction, allograft or autograft reconstruction, arthrodesis, and hip transposition. Each of these procedures has its own advantages and disadvantages, and there is no consensus or gold standard for periacetabular reconstruction. Consequently, this review provides an overview of the clinical outcomes for each of these reconstructive options following pelvic tumor resections. Overall, high complication rates are associated with the use of massive implants/grafts, and deep infection is generally the most common cause of reconstruction failure. Functional outcomes decline with the occurrence of severe complications. Further efforts to avoid complications using innovative techniques, such as antibiotic-laden devices, computer navigation, custom cutting jigs, and reduced use of implants/grafts, are crucial to improve outcomes, especially in patients at a high risk of complications.

Limb-salvage reconstruction following resection of pelvic bone sarcomas involving the acetabulum

AIMS

Limb salvage for pelvic sarcomas involving the acetabulum is a major surgical challenge. There remains no consensus about what is the optimum type of reconstruction after resection of the tumour. The aim of this study was to evaluate the surgical outcomes in these patients according to the methods of periacetabular reconstruction.

METHODS

The study involved a consecutive series of 122 patients with a periacetabular bone sarcoma who underwent limb-salvage surgery involving a custom-made prosthesis in 65 (53%), an ice-cream cone prosthesis in 21 (17%), an extracorporeal irradiated autograft in 18 (15%), and nonskeletal reconstruction in 18 (15%).

RESULTS

The rates of major complications necessitating further surgery were 62%, 24%, 56%, and 17% for custom-made prostheses, ice-cream cone prostheses, irradiated autografts and nonskeletal reconstructions, respectively (p = 0.001). The ten-year cumulative incidence of failure of the reconstruction was 19%, 9%, 33%, and 0%, respectively. The major cause of failure was deep infection (11%), followed by local recurrence (6%). The mean functional Musculoskeletal Tumour Society (MSTS) scores were 59%, 74%, 64%, and 72%, respectively. The scores were significantly lower in patients with major complications than in those without complications (mean 52% (SD 20%) vs 74% (SD 19%); p < 0.001). For periacetabular resections involving the ilium, the mean score was the highest with custom-made prostheses (82% (SD 10%)) in patients without any major complication; however, nonskeletal reconstruction resulted in the highest mean scores (78% (SD 12%)) in patients who had major complications. For periacetabular resections not involving the ilium, significantly higher mean scores were obtained with ice-cream cone prostheses (79% (SD 17%); p = 0.031).

CONCLUSION

Functional outcome following periacetabular reconstruction is closely associated with the occurrence of complications requiring further surgery. For tumours treated with periacetabular and iliac resection, skeletal reconstruction may result in the best outcomes in the absence of complications, whereas nonskeletal reconstruction is a reasonable option if the risk of complications is high. For tumours requiring periacetabular resection without the ilium, reconstruction using an ice-cream cone prosthesis supported by antibiotic-laden cement is a reliable option. Cite this article: Bone Joint J 2021;103-B(4):795-803.

Pelvic reconstruction using an ice-cream cone prosthesis: correlation between the inserted length of the coned stem and surgical outcome

BACKGROUND

Acetabular reconstruction using an ice-cream cone prosthesis has been a reliable reconstruction option following pelvic tumour resection. However, it remains unknown which factor determines the success of this procedure. We aimed to determine risk factors for complications and functional loss in acetabular reconstruction using an ice-cream cone prosthesis.

PATIENTS AND METHODS

Fifty-four patients with malignant bone tumours who underwent acetabular reconstruction using an ice-cream cone prosthesis between 2004 and 2016 were studied. The bone-stem ratio was calculated as the ratio of the inserted length into the bone per the entire stem length.

RESULTS

A total of 26 (48%) patients had at least one complication and 11 patients (20%) required surgical interventions. The complication rates were 71% and 40% with a bone-stem ratio ≤ 50% and > 50%, respectively (p = 0.026), and the bone-stem ratio significantly stratified the risk of complications (≤ 50%: OR, 4.67 versus > 50%; p = 0.048). The mean MSTS score at the final follow-up was 60% (range 23-97%): the scores were significantly lower in patients with complications/leg-length discrepancy (52%) than in those without (79%; p = 0.002). The mean score with a bone-stem ratio ≤ 50% was significantly lower than the score with a ratio > 50%, especially in patients who underwent non-navigated reconstructions (33% versus 64%; p = 0.001).

CONCLUSION

The inserted length of the coned stem into residual bone was predictive of complications and functional outcome. Surgical indication for this procedure should be considered with the size of the remaining ilium to stabilise the prosthesis with a coned stem longer than half length.

Comparison of reconstructive techniques after acetabular resection for pelvic chondrosarcoma

AIMS

Hip reconstruction after resection of a periacetabular chondrosarcoma is complex and associated with a high rate of complications. Previous reports have compared no reconstruction with historical techniques that are no longer used. The aim of this study was to compare the results of tantalum acetabular reconstruction to both historical techniques and no reconstruction.

METHODS

We reviewed 66 patients (45 males and 21 females) with a mean age of 53 years (24 to 81) who had undergone acetabular resection for chondrosarcoma. A total of 36 patients (54%) underwent acetabular reconstruction, most commonly with a saddle prosthesis (n = 13; 36%) or a tantalum total hip arthroplasty (THA) (n = 10; 28%). Mean follow-up was nine years (SD 4).

RESULTS

There was no difference in the mean age (p = 0.63), sex (p = 0.110), tumour volume (p = 0.646), or type of resection carried out (p > 0.05) between patients with and without reconstruction. Of the original 66 patients, 61 (92%) were ambulant at final follow-up. There was no difference in the proportion of patients who could walk in the reconstruction and 'no reconstruction' groups (p = 0.649). There was no difference in the mean Musculoskeletal Tumor Society (MSTS) score between patients who were reconstructed and those who were not (61% vs 56%; p = 0.378). Patients with a tantalum THA had a significantly (p = 0.015) higher mean MSTS score (78%) than those who were reconstructed with a saddle prosthesis (47%) or who had not been reconstructed (56%). Patients who had undergone reconstruction were more likely to have complications (81% vs 53%; p = 0.033).

CONCLUSION

Reconstruction after resection of the acetabulum is technically demanding. In selected cases, reconstruction is of benefit, especially when reconstruction is by tantalum THA; however, the follow-up for these patients remains mid-term. When not feasible, patients with no reconstruction have an acceptable functional outcome. Level of Evidence: Level III Therapeutic. Cite this article: Bone Joint J 2021;103-B(2):391-397.

Preliminary proposal: a classification system for reconstruction with autologous femoral head after periacetabular tumors resection

BACKGROUND

Although researchers have adopted various methods for the resection and reconstruction of periacetabular tumors, the total incidence rate of complications remains high. Aiming for preserving the acetabulum and reducing the risk of complications, we applied a surgery method using tumor-free autologous femoral head to reconstruct the defective acetabulum after resection of periacetabular tumors followed by performing a conventional total hip arthroplasty (THA). Moreover, we proposed a preliminary classification system for these surgery methods.

METHODS

We retrospectively reviewed 6 patients treated with acetabulum reconstruction combined with autologous femoral head following peri-acetabulum resection between April 2010 and May 2018. All patients were diagnosed as periacetabular tumors including chondrosarcoma (n = 5) and chondroblastoma (n = 1). Clinical data such as age, diagnosis, complications, local recurrence or metastasis, and function (Musculoskeletal Tumor Society 1993, MSTS93) were documented. The average time of follow-up was 62.5 months (range, 17 to 106 months).

RESULTS

A total of 5 patients survive with average MSTS93 score of 27.8 points (range, 26-30). One patient, suffering from multiple bone metastasis prior treatment, ended up dying. One who had received radiotherapy before surgery had poor incision healing. Further, a classification system was preliminary proposed in 2 patients involving the pubis (type A) and 4 patients involving ischium (type B).

CONCLUSIONS

Based on the results, we preliminary proposed a classification system for reconstruction with autologous femoral head after periacetabular low malignant tumors resection. The clinical results suggested that surgery methods involving pubis (type A) and ischium (Type B) are safe and feasible. However, further researches should be conducted to verify our classification system.

Unrecognized Chondrosarcoma as a Cause of Total Hip Arthroplasty Failure

Background

Total hip arthroplasty (THA) is one of the most successful procedures in orthopedic surgery. The most frequent THA indications are osteoarthritis and avascular necrosis, whereas symptomatic aseptic loosening is the most common indication to revision surgery. Chondrosarcoma (CS) is the most frequent bone sarcoma in adults, and proximal femur is the most prevalent location. Wide resection is the treatment of choice.We report 3 cases of unrecognized high-grade CS in the setting of primary or revision THA and reviewed the literature on this rare clinical presentation.

Methods

A systematic literature review on CS in the setting of THA, published between 1980 and 2020, was performed on PubMed, Embase, Medline, Ovid SP, and Web of Science, using the guidelines set in the Preferred Reporting Items for Systematic Reviews and Mata-analyses (PRISMA).

Results

Case series: Three patients were referred to our sarcoma center after failure of THA due to unrecognized high-grade CS. All 3 had rapid fatal outcome. Literature review: Fifty-nine articles were identified, of which 8 were included in the study. They confirmed that primary or revision THA failure due to unrecognized CS is extremely rare, with only few cases reported in the literature.

Conclusions

Before proceeding to primary or revision arthroplasty, diagnosis must be ascertained. Atypical presentation of a common pathology, such as osteoarthritis, avascular necrosis, or aseptic loosening of an endoprosthesis, should raise suspicion for another cause to symptoms, and additional workup be performed. As our cases demonstrated, unrecognized or inadequately managed bone sarcoma may lead to poor or even fatal outcome.

What are the Complications of Three-dimensionally Printed, Custom-made, Integrative Hemipelvic Endoprostheses in Patients with Primary Malignancies Involving the Acetabulum, and What is the Function of These Patients?

BACKGROUND

Functional reconstruction after resection of pelvic malignancies involving the acetabulum remains challenging. Numerous reconstruction methods have been proposed, but they are generally associated with mechanical and nonmechanical complications. To improve the function of patients with primary malignancies of the acetabulum after internal hemipelvectomy and reduce the complication rate after this procedure, we designed a series of three-dimensionally (3D) printed, custom-made, integrative hemipelvic endoprostheses with a porous structure and wanted to present the early results of using this construct to determine whether it could be considered a reasonable reconstruction option.

QUESTIONS/PURPOSES

We performed this study to (1) evaluate, in a small group of patients, whether the new endoprosthesis restores short-term lower-limb function; (2) identify short-term complications associated with the use of this endoprosthesis; and (3) assess osseointegration between the host bone and the 3D-printed integrative hemipelvic endoprosthesis with a porous structure.

METHODS

Between October 2016 and May 2017, our center treated 26 patients with malignancies involving the acetabulum. Thirteen of these patients received hemipelvic replacement with a 3D-printed, custom-made, integrative endoprosthesis, six received hemipelvic replacement with a modular endoprosthesis, four received radiotherapy, and three received external hemipelvectomy. Resection and reconstruction with a 3D-printed, custom-made, integrative endoprosthesis were indicated if the resection margin was the same as that achieved in hemipelvectomy, if reconstruction would preserve reasonable function after resection, if the patient had a good physical status and life expectancy longer than 6 months, and if the patient was willing to accept the potential risk of a 3D-printed, custom-made, endoprosthesis. The exclusion criteria were an inability to achieve a satisfactory surgical margin with limb salvage, inability to preserve the function of the limb because of tumor involvement of the sacral nerve or sciatic nerve, and unresectable and/or widely metastatic disease on presentation. Pain and function were evaluated with the 10-cm VAS score (range 0 to 10; a lower score is desirable), the 1993 version of the Musculoskeletal Tumor Society (MSTS-93) score (range 0 to 30; a higher score is desirable), and the Harris hip score ([HHS]; range 0 to 100; a higher score is desirable) were evaluated preoperatively and at a median of 27 months after reconstruction (range 24 to 31 months). The functional scores and complications were recorded after reviewing the patients' records. Osseointegration was assessed with digital tomosynthesis by two senior surgeons. We observed the trabecular structures connected to the implant surface to assess whether there was good osseointegration.

RESULTS

The median preoperative VAS score, MSTS-93 score, and HHS were 5 (range 2 to 8), 14 (range 3 to 18), and 64 (range 20 to 76) points, respectively. At the latest follow-up interval, the median VAS score, MSTS-93 score, and HHS were 2 (range 0 to 6), 23 (range 15 to 27), and 82 (range 44 to 93) points, respectively. No deep infection, dislocation, endoprosthetic breakage, aseptic loosening, or local recurrence occurred. Two patients experienced delayed wound healing; the wounds healed after débridement. Using digital tomography, we found that all implants were well-osseointegrated at the final follow-up examination.

CONCLUSIONS

A 3D-printed, custom-made, integrative hemipelvic endoprosthesis provides acceptable early outcomes in patients undergoing pelvic reconstruction. Osseointegration is possible, and we anticipate this will lead to biologic stability with a longer follow-up interval. The custom-made integrative design ensured precise implantation. Although a few patients in this study had only a short follow-up duration, the functional results were reasonable. We have observed no major complications so far, but this was a very small series and we caution that these are large reconstructions that will certainly result in complications for some patients. Our method uses a precise preoperative simulation and endoprosthesis design to aid the surgeon in performing challenging operations. If our early results are confirmed with more patients and longer follow-up and are replicated at other centers, this may be a reconstruction option for patients with periacetabular malignancies.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

3D-Printed Modular Hemipelvic Endoprosthetic Reconstruction Following Periacetabular Tumor Resection: Early Results of 80 Consecutive Cases

BACKGROUND

Reconstruction with an endoprosthesis following pelvic tumor resection has increased over the years. However, the long-term results reflect a disappointing frequency of mechanical complications and failures. In an attempt to enhance implant fixation, an electron beam melting (EBM)-based modular hemipelvic endoprosthesis was introduced. Our aim was to explore the preliminary clinical outcomes for patients who have been managed with this prosthesis.

METHODS

We reviewed the records of 80 consecutive patients who had been managed at a single center between June 2015 and September 2017. Chondrosarcoma was the predominant diagnosis (31.3%). Osseous metastases were diagnosed in 16 patients (20.0%). The position of the reconstructed metallic acetabulum was measured on an anteroposterior pelvic radiograph. Bone ingrowth was evaluated in 2 samples harvested from patients with tumor recurrence.

RESULTS

After a median duration of follow-up of 32.5 months (range, 9 to 52 months), no acetabular component instability was detected on radiographs. Histological sectioning of specimens harvested from 2 patients with tumor recurrence showed bone trabeculae extending toward the implant and bone ingrowth within the porous network. At the time of the latest follow-up, 59 patients (73.8%) were alive with no evidence of disease, 5 patients (6.3%) were alive with disease, and 16 patients (20.0%) had died of disease. Local recurrence occurred in 9 patients (11.3%). The mean Musculoskeletal Tumor Society score at the time of the latest follow-up was 83.9% (range, 43% to 100%). Complications occurred in 16 patients (20%), with wound dehiscence being the most common complication (8 patients; 10%). No aseptic loosening was found. Five patients (6.3%) had deep infection, and 2 patients (2.5%) had dislocation.

CONCLUSIONS

The use of a 3-dimensional (3D)-printed modular hemipelvic endoprosthesis with a highly porous metal interface represents a potential choice as a pelvic endoprosthesis after internal hemipelvectomy for the treatment of a primary or metastatic tumor. These preliminary results demonstrate stable fixation with acceptable early functional and radiographic outcomes.

LEVEL OF EVIDENCE

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

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.

Varus-Valgus Constrained Implants With a Mobile-Bearing Articulation: Results of 367 Revision Total Knee Arthroplasties

BACKGROUND

Varus-valgus constrained (VVC) implants are used for compromised ligamentous stability in revision total knee arthroplasties (TKAs). Mobile-bearing VVC implants may reduce rotational forces; yet, limited clinical data exist. The purpose of this study is to report mid-term risk of re-revision, complications, and clinical outcomes with a mobile-bearing VVC implant.

METHODS

Three hundred thirty-seven patients (367 TKAs) who underwent revision TKA with a mobile-bearing VVC implant between 1999 and 2013 at a single institution were reviewed. Mean age at revision was 67 years. Mean follow-up was 4 years. The main indications for revision were aseptic loosening in 158 cases (43%), reimplantation after 2-stage exchange arthroplasty in 120 (33%), instability in 61 (17%), and other in 28 (7%). Clinical outcomes were assessed by Knee Society Scores, and survivorship was analyzed with death as the competing risk.

RESULTS

The 5-year cumulative incidences of any re-revision or re-revision for aseptic loosening were 9% and 3%, respectively. Twenty-six knees (7%) were re-revised: 15 for infection, 6 for aseptic loosening, and 5 for other causes. There were 17 cases of irrigation and debridement, 10 cases of manipulations under anesthesia, and 9 cases of periprosthetic fractures. There were no bearing "spin-outs." The mean Knee Society Scores improved from 45 preoperatively to 77 at most recent follow-up (P < .001).

CONCLUSION

The functional improvement and 5-year cumulative incidence of revision of a mobile-bearing VVC implant demonstrated acceptable outcomes with no unique complications related to the mobile-bearing construct. Additional follow-up will be needed to determine long-term implant survivorship.

Mild Coronal Stem Malalignment Does Not Negatively Impact Survivorship or Clinical Results in Uncemented Primary Total Hip Arthroplasties With Dual-Tapered Implants

BACKGROUND

Proper component positioning in total hip arthroplasty (THA) is crucial for implant fixation and hip stability. The purpose of this study is to assess if neutral coronal stem alignment (0° ± 3°) improved long-term survivorship in uncemented femoral components.

METHODS

Between 2005 and 2010, 1028 primary THAs were performed with 2 contemporary dual-tapered, proximally coated uncemented stem types. Alignment was measured immediately postoperatively and at most recent follow-up. In total, 978 femoral stems (95%) were within 0° ± 3° of the neutral anatomic coronal axis, and the 50 stems (5%) outside that range were considered outliers (3.1° of valgus to 4.8° of varus). Outcomes analyzed included implant survivorship, Harris Hip Scores, and incidence of dislocation. Mean follow-up was 5 years.

RESULTS

Survivorship free of aseptic femoral component loosening was 99.3% and 98.2% at 5 and 8 years in the neutral group vs 100% at 5 and 8 years in the outlier group (P = .98). Survivorship free of femoral component revision for any reason was 99.1% and 97.3% at 5 and 8 years vs 100% at 5 and 8 years, respectively (P = .80). Harris Hip Scores were similar (89 in both groups; P = .84) at most recent follow-up. The incidence of mild to moderate thigh pain was also similar in both groups (6.1% vs 6%, P = .85). The incidence of dislocation was 1.5% at 8 years, and similar between both groups (P = .77).

CONCLUSION

Slight malalignment of contemporary dual-tapered uncemented THA femoral components does not appear to negatively impact survivorship or clinical outcomes, which is in contrast to cemented femoral components.

LEVEL OF EVIDENCE III

Case-control study.

Rapid return to function and stability with dual mobility components cemented into an acetabular reconstructive cage for large osseous defects in the setting of periacetabular metastatic disease

BACKGROUND AND OBJECTIVES

Large acetabular defects secondary to metastatic disease frequently require extensive acetabular reconstruction. Techniques of acetabular reconstruction have been described, but no consensus for the management of these defects has been reached so far. We present our technique and patient outcomes for acetabular reconstruction by cementing a dual mobility cup into an acetabular cage.

METHODS

We reviewed 152 total hip arthroplasties and identified 19 patients with periacetabular metastatic disease and large defects who required acetabular reconstruction utilizing a dual mobility cup cemented into an acetabular reconstructive cage. The following outcomes were evaluated: pain relief, functional improvement, postoperative complications.

RESULTS

Mean follow-up was 3 years, with 13 of the 19 patients eligible for 2-year follow-up. Patients reported a significant improvement in both pain and functional outcomes. There were no dislocations or signs of loosening. Two patients developed postoperative infections. One patient required hemipelvectomy 16 months postop due to recurrence of metastatic disease.

CONCLUSIONS

Cementing a dual mobility cup into an acetabular cage provides a highly stable and durable option for patients with periacetabular metastatic disease and large defects. Patients are able to return to immediate full weight bearing with significant improvement in both function and pain at 2 years.

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.