Outcome of expandable prostheses in children

Management of limb length discrepancy after bone sarcoma resection about the knee in the skeletally immature

Patients with bone sarcomas increasingly choose limb salvage. This can lead to issues with limb length discrepancy (LLD) for the skeletally immature. We synthesize management options into an algorithm and report our results. Patients with bone sarcomas involving any location from the femoral diaphysis to the tibial diaphysis 12 years or younger were reviewed. Our clinical pathway prescribed patients with metadiaphyseal lesions to intercalary allograft reconstruction, epiphyseal lesions and less than 5 cm expected LLD to osteoarticular allograft and patients with more than 5 cm expected LLD to extendable prosthesis. Twenty patients met inclusion criteria: 11 with osteoarticular allografts, 5 with extendable prostheses and 4 with intercalary allografts; median age 11.5 years; median follow-up 8.2 years; and final median LLD 1.6 cm. Five patients had contralateral epiphysiodesis, two patients underwent contralateral femoral shortening and a median of 6 (range 4-8) lengthenings were performed for extendable prostheses. Four patients had residual LLD over 3 cm. There were 13 revisions in 8 patients and 2 amputations. Limb-salvage in paediatric bone sarcoma of the knee can be managed with multiple techniques producing satisfactory results in regards to LLD. Careful pre-operative planning and shared decision making is a requisite given the high rate of secondary procedures for both LLD and reconstructive failures. Level of evidence: Level III Retrospective Comparative Study.

Endoprosthetic replacement with preservation of the epiphysis for proximal tibial reconstruction after osteosarcoma resection in children: a case report

BACKGROUND

Limb salvage surgery is an important method for treating malignant tumors of the bone involving the adjacent parts of the major joints in children. This technique allows for preservation of limb function, especially in the lower limb. However, the reconstruction of the proximal end of the tibia after removing the tumor mass with a rational scale to preserve the total knee joint and reduce limb length discrepancy presents a challenge.

CASE PRESENTATION

We present a case of osteosarcoma of the proximal tibia. After being treated with an extended tumor resection, the proximal tibia of the child was restructured using endoprosthetic replacement with epiphyseal preservation. This procedure preserves the entire articular surface and growth plate of the knee joint of the affected limb and provides a feasible alternative protocol for retaining the function and growth potential of the affected limb. The patient remained disease-free and normal limb motor function was observed during the 3.5 year follow-up since the initial surgery.

CONCLUSIONS

Preservation of the epiphysis enabled our patient to perform better limb function after limb-saving surgery as a result of his undamaged knee joint and minimized limb-length discrepancy. We believe that endoprosthetic replacement with preservation of the epiphysis can provide the best strategy for reconstruction after resection of focal malignant tumors in long bones without epiphytic involvement.

Distraction Osteogenesis Reconstruction Following Resection of Bone Sarcomas: Surgical, Functional, and Oncological Outcomes from a Prospective Trial Analysis

BACKGROUND

While sustainable long-term function has been established for biological reconstruction with distraction osteogenesis (DO) following osseous resections, there is a paucity of published data informing surgeons and patients on important milestones in the reconstructive process. The objectives of this study were to determine when to expect complete bone healing and full weight-bearing as well as to quantify the influence of chemotherapy on the osseous regeneration process.

METHODS

Prospectively, pathological and clinical data were collected for 30 consecutive patients who underwent primary or secondary DO-based reconstruction following osseous resection from 2018 to 2021. Serial radiographs indicated the times to cortex formation and full union. An unpaired t test was used to compare the time required for full bone remodeling of segments transported with and without concurrent chemotherapy.

RESULTS

The average resection length was 13.6 cm (range, 4 to 22 cm). Patients underwent an average of 6.1 procedures (range, 1 to 14 procedures). Half (50%) of all procedures were planned, while half were unplanned procedures. All patients achieved full, independent weight-bearing at a median of 12 months (interquartile range [IQR], 9 to 16 months). For the 34 segments transported concurrently with chemotherapy, the mean bone healing index (BHI) was 2.3 ± 0.7, and the mean BHI was 1.2 ± 0.4 for the 25 segments without chemotherapy at any point during their transport (p < 0.0001).

CONCLUSIONS

All 30 patients achieved full bone healing and independent weight-bearing at a median of 1 year postoperatively and continued to show functional improvement afterward. Surgeons and patients can expect bone healing to be nearly twice as fast for segments transported after completion of systemic chemotherapy compared with segments transported concurrently with adjuvant chemotherapy.

LEVEL OF EVIDENCE

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

Expandable endoprostheses in skeletally immature patients: Where we are

Approximately 45 percent of malignant bone tumors are seen under the age of 16 and one of the important results of growth plate sacrification in patients with immature skeletons is limb inequality. Until the early 1990s, the treatment options for these patients were rotationplasty or amputation. Multimodal approaches that combine imaging, chemotherapy, and surgical techniques have enabled the development of limb-preserving methods with satisfactory results. In order to overcome inequality problems, expandable prostheses have been developed in the 1980s. Extendable endoprosthesis replacements have been improved over the years and are now an established and safe alternative. Noninvasive prostheses appear to be advantageous compared to minimally invasive expandable prostheses that require multiple surgical procedures, but the complication rate remains high. Therefore, although expandable prostheses are not the definitive answer to the treatment of bone sarcomas in skeletally immature children, they are still a suitable interim choice until full adulthood is achieved. Due to reported high complication rates, the procedures require significant experience and are recommended for use only in specialized cancer centers.

A classification system of joint-salvage tumor resection in osteosarcoma of the knee: A retrospective cohort study

BACKGROUND

Joint-preserving surgery is possible for patients with juxta-articular osteosarcoma of the knee, even when the tumor invades the epiphysis. Oncologic and functional outcomes may vary due to the extent of tumor invasion, the amount of epiphysis preservation, and reconstruction methods. We aimed to introduce a novel classification facilitating clinical evaluation of different surgical treatments.

METHODS

We identified 52 patients with osteosarcoma of the knee undergoing joint-preserving tumor resection and intercalary reconstruction. We classified procedures into two types and six subtypes based on the tumor location and adjuvant treatment employed. Oncologic outcomes, limb function and complications were compared among different types.

RESULTS

None of the patients had a local recurrence in the preserved epiphysis apart from three (5.7 %) who had local recurrence in soft tissue. Overall survival rate of the patients was 82.7 % at 5 and 10 years. There was no difference in survival rate (P = 0.909), local recurrence (P = 0.642) between type I (tumor not invading epiphysis) and type II (tumor invading epiphysis). In addition to one skin necrosis in the 3D-printed prosthesis reconstruction and one infection in Capanna reconstruction, all complications necessitating additional surgery occurred in allograft. The Musculoskeletal Tumor Society (MSTS) scores ranged from 21 to 30 with a median of 26. There were differences in the MSTS scores among six subgroups (P = 0.015), with the highest in type Ia and the lowest in type IIc. The less of the viable epiphysis retained, the worse the knee function was at long-term follow up.

CONCLUSIONS

The suggested classification can guide surgical strategy and is convenient for comparison of the functional results.

Femoral Discrepancy After Childhood Bone Sarcoma Surgery Can Be Treated With Magnetic Intramedullary Nails

This study aims to determine whether femoral lengthening with a magnetic motorized intramedullary nail (PRECICE; NuVasive) is safe and effective in patients with discrepancy due to limb salvage performed for bone sarcomas before skeletal maturity. Six patients (male, 4; female, 2) with a mean age of 9.3 years (range, 4.8-12.8 years) at the time of index limb salvage surgery were retrospectively analyzed. Four patients had undergone biological reconstruction with liquid-nitrogen recycled frozen autograft shell and inlaid vascular fibula combination and 2 had undergone nonbiological reconstruction with distal femur modular tumor endoprosthesis. The mean age at PRECICE operation was 16.1 years (range, 13.4-20.1 years). The mean prelengthening femoral discrepancy was measured as 60 mm (range, 39-80 mm). Lengthening was achieved in 5 of these 6 patients. Although the PRECICE nail was successfully implanted in the sixth patient, lengthening could never be performed owing to failure to overcome the chronic diaphyseal nonunion first, as intended with compressive use of the nail. For the other 5 patients, in whom lengthening was performed, the mean lengthening was 45 mm (range, 35-52 mm), the mean ratio of achieved to planned lengthening was 93% (range, 74%-100%), and the mean bone-healing index was 41 days per cm (range, 24-69 days per cm). Mean Musculoskeletal Tumor Society score improved from 25.6 to 27.2 after lengthening. No major complications occurred. The outcomes of this study demonstrate that the PRECICE implant can safely and effectively correct femoral length discrepancy caused by limb salvage performed for osteosarcoma before skeletal maturity. [Orthopedics. 2023;46(1):27-34.].

Outcomes of Fixed-Hinged Knee Prosthesis for Distal Femoral Osteosarcoma in Skeletally Immature Patients: First Results

The best surgical choice for distal femur osteosarcoma in skeletally immature patients remains controversial. A fixed hinged knee prosthesis has been designed to preserve the growth plates in the adjacent tibia, expecting tibial growth to be continued. This study aims to report the (1) clinical outcomes after prosthetic replacement, (2) postoperative complications, and (3) length of discrepancy of the operative tibia with the unaffected tibia. Thirty-four skeletally immature patients (averaged 9 years at surgery; range, 5-12 years) with distal femoral osteosarcoma underwent placement of this hinged knee prosthesis between January 2015 and August 2018. Postoperative function and complications were assessed. Length discrepancy was measured using a series of full-length standing anteroposterior radiographs of the bilateral lower extremity. The average follow-up duration was 34 months (2.8 years). In the last follow-up, four patients expired because of pulmonary metastasis. Two patients presented with local recurrence of the soft tissue. Postoperatively, the flexion range of the knee joint range was between 100 and 130 degrees, with an average of 115.2 degrees. The mean functional score of living patients evaluated using the Musculoskeletal Tumor Society scoring system was 89.2% (range, 76.7-100%). Types 1 (three patients), 2 (one patient), 3 (two patients), and 5 (two patients) complications exist. Among them, three patients received revision surgery. The proximal tibial physis still grew after surgery, with an average of 74.3% (range, 30-100%) growth potential compared with the unaffected proximal tibial physis. Moreover, 27 children exhibited tibial length discrepancy compared with the contralateral tibia, and the mean discrepancy in tibial length was 1.1 cm (range, 0.2-3.1 cm). This hinged knee prosthesis can keep the growth potential in the adjacent tibia, provides satisfying functional outcomes, and has a lower postoperative complication rate. Thus, it could serve as an alternative intervention for distal femoral osteosarcoma in skeletally immature patients.

Epiphyseal distraction prior to resection in paediatric bone sarcomas : four decades of experience

Paediatric bone sarcomas are a dual challenge for orthopaedic surgeons in terms of tumour resection and reconstruction, as it is important to minimize functional and growth problems without compromising survival rates. Cañadell's technique consists of a Type I epiphysiolysis performed using continuous distraction by an external fixator prior to resection. It was designed to achieve a safe margin due to the ability of the physeal cartilage to be a barrier to tumour spread in some situations, avoiding the need for articular reconstruction, and preserving the growth capacity most of the times. Despite initial doubts raised in the scientific community, this technique is now widely used in many countries for the treatment of metaphyseal paediatric bone sarcomas. This annotation highlights the importance of Cañadell's work and reviews the experience of applying it to bone sarcoma patients over the last 40 years.Cite this article: Bone Joint J 2023;105-B(1):11-16.

Three-dimensional printed customized uncemented unipolar prosthesis combined with ligament reconstruction for tumorous defect of the distal femur in children

BACKGROUND

Hemiarthroplasty following tumor resection of the distal femur in children provides a chance to preserve the proximal tibial physis for limb elongation. Based on three-dimensional (3D) printing technology, the uncemented unipolar prosthesis with joint stability reinforced structures (JSRSs) was custom-designed for our cases. This study aimed to describe the design and assess the short-term outcomes of this refined prosthetic hemiarthroplasty.

METHODS

Seven patients (four females and three males) received 3D-printed customized uncemented unipolar prosthesis for hemiarthroplasty after removal of the distal femur, from September 2019 to October 2020 at our Orthopedics department. The limb function, growth of the preserved proximal tibial physis, joint stability, and limb length discrepancy (LLD) were assessed. Complications were recorded.

RESULTS

Six patients survived with no evidence of metastasis or local recurrence at the last follow-up, and one patient died of lung metastasis at 19 months postoperatively. Follow-up ranged from 19 to 32 months, with an average of 26 months. Elongation of the tibia was observed in all cases. At the last follow-up, four patients exhibited equal growth length compared with the healthy contralateral tibia. LLD ranged from 0.8 to 1.6 cm with a mean of 1.3 cm. The average knee range of motion was 95.3° of flexion and 4.5° of extension. All patients achieved satisfactory postoperative limb function with a mean MSTS score of 25.8. The results of the drawer, Lachman, and pivot shift tests were negative in all patients. During follow-up, painless joint space narrowing was observed in two patients. The screw for ligament fixation loosened in one of the seven patients at 17 months postoperatively. No subluxation of the joint, angular deformity, or breakage of the implant was detected in the remaining patients.

CONCLUSIONS

3D-printed customized uncemented unipolar prosthesis with JSRS would be a good choice for reconstructing tumorous defect in the distal femur in children.

Osteosarcoma

Osteosarcoma is the most common primary malignant tumour of the bone. Osteosarcoma incidence is bimodal, peaking at 18 and 60 years of age, and is slightly more common in males. The key pathophysiological mechanism involves several possible genetic drivers of disease linked to bone formation, causing malignant progression and metastasis. While there have been significant improvements in the outcome of patients with localized disease, with event-free survival outcomes exceeding 60%, in patients with metastatic disease, event-free survival outcomes remain poor at less than 30%. The suspicion of osteosarcoma based on radiographs still requires pathological evaluation of a bone biopsy specimen for definitive diagnosis and CT imaging of the chest should be performed to identify lung nodules. So far, population-based screening and surveillance strategies have not been implemented due to the rarity of osteosarcoma and the lack of reliable markers. Current screening focuses only on groups at high risk such as patients with genetic cancer predisposition syndromes. Management of osteosarcoma requires a multidisciplinary team of paediatric and medical oncologists, orthopaedic and general surgeons, pathologists, radiologists and specialist nurses. Survivors of osteosarcoma require specialized medical follow-up, as curative treatment consisting of chemotherapy and surgery has long-term adverse effects, which also affect the quality of life of patients. The development of osteosarcoma model systems and related research as well as the evaluation of new treatment approaches are ongoing to improve disease outcomes, especially for patients with metastases.

Tibia Multiplanar Deformities and Growth Disturbance Following Expandable Endoprosthetic Distal Femur Replacement

Background: Expandable distal femur endoprosthesis (EDFE) is commonly used to compensate for the loss of the distal femoral epiphyseal plate in skeletally immature children who have undergone surgical resection of bone malignancies. However, the effect of the passive tibial component of the EDFE on tibial growth has not been extensively studied in the literature. This study aims to delineate the type, frequency, and associated risk factors of multiplanar proximal tibial deformities in skeletally immature children following the use of the expandable distal femur endoprosthesis (EDFE). Moreover, we plan to detect how these deformities influence the long-term functionality of the endoprosthesis in defining the need for subsequent implant revision or further surgical management. Patients and Methods: A total of 20 patients aged (7−12) years underwent expandable distal femur replacement. Two types of implants were used: Juvenile Tumor System (JTS) non-invasive prosthesis in 14 patients, and Modular Universal Tumor and Revision System (MUTARS)® Xpand Growing Prostheses in six patients. A scanogram and CT scan documented the measurements of longitudinal and multiplanar growth as leg length discrepancy (LLD), femur length discrepancy (FLD), tibia length discrepancy (TLD), and the yield values of rotational, sagittal, and coronal deformities of the tibia. The patients were followed up to assess the need for further management. Sex, age, size of tibial plate perforation, and type of implant used were studied for possible correlation with deformities or growth disturbance. Results: The patients were followed up for a mean of 3 (2−7) years. A total of 14 patients, (10 JTS, 4 implant cast) had a tibial deformity and/or growth disturbance. A single patient was found to have all deformities (growth, rotational, coronal, and sagittal). Fourteen patients were found to have an LLD ranging from 5.3 to 59 mm (median 21 mm), 12 had a TLD from 3 to 30 mm, (median 10 mm), and 11 patients showed evidence of malrotation from 6 to 32 degrees (median 11 degrees). TLD was found to contribute entirely to LLD in three patients, and >50% of LLDs in seven patients. All LLDs were treated conservatively, except in three patients; two received contralateral tibia epiphysiodesis and one received revision with a new implant. A single patient had a posterior tibia slope angle (PTSA) of −2.8 degrees, and three patients had a coronal deformity with a mean medial proximal tibia angle (MPTA) of 80.3 (77−83 degrees). Conclusions: Tibial growth disturbance and multiplanar deformities occur in the majority of patients following EDFE replacement, exacerbating LLD. Yet, these disturbances may be well tolerated, managed conservatively, and rarely mandate endoprosthetic revision or subsequent corrective surgery. Age at the time of surgery was found to be the only significant contributor to the development of tibia growth disturbance.

Survival and failure modes of the Compress® spindle and expandable distal femur endoprosthesis among pediatric patients: A multi‐institutional study

BACKGROUND

Expandable endoprostheses can be used to equalize limb length for pediatric patients requiring reconstruction following large bony oncologic resections. Outcomes of the Compress® Compliant Pre-Stress (CPS) spindle paired with an Orthopedic Salvage System expandable distal femur endoprosthesis have not been reported.

METHODS

We conducted a multi-institutional retrospective study of pediatric patients with distal femoral bone sarcomas reconstructed with the above endoprostheses. Statistical analysis utilized Kaplan-Meier survival technique and competing risk analysis.

RESULTS

Thirty-six patients were included from five institutions. Spindle survivorship was 86.3% (95% confidence interval [CI], 67.7-93.5) at 10 years. Two patients had a failure of osseointegration (5.7%), both within 12 months. Twenty-two (59%) patients had 70 lengthening procedures, with mean expansions of 3.2 cm (range: 1-9) over 3.4 surgeries. The expandable mechanism failed in eight patients with a cumulative incidence of 16.1% (95% CI, 5.6-31.5) at 5 years. Twenty-nine patients sustained International Society of Limb Salvage failures requiring 63 unplanned surgeries. Periprosthetic joint infection occurred in six patients (16.7%). Limb preservation rate was 91% at 10 years.

CONCLUSIONS

There is a high rate of osseointegration of the Compress® spindle among pediatric patients when coupled with an expandable implant. However, there is a high rate of expansion mechanism failure and prosthetic joint infections requiring revision surgery.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Outcomes of Semiknee Replacement in Skeletally Immature Bone Sarcoma Patients

INTRODUCTION

 A semiknee mega endoprosthesis (SKMEP) was used to replace the resected distal femur or proximal tibia in skeletally immature bone sarcoma patients. This study investigated the surgical technique, endoprosthesis survival rate, functional outcome, complications, and approaches to resolve limb-length discrepancy (LLD) following this procedure.

PATIENTS AND METHODS

 In total, 15 girls and 16 boys with a mean age of 9.1 years (range, 4-12) and 8.9 years (range, 5-13), respectively, were included in this study. The mean length of the resected distal femur (15 cases) and proximal tibia (16) was 145.0 and 122.8 mm, respectively. Altogether, 19 custom-made SKMEPs and 12 modular units were used to reconstruct the bone and joint defects.

RESULTS

 The average follow-up was 82.8 months (range, 4-225 months). Five patients died of disease. Seven SKMEPs were revised to total knee endoprosthesis after a mean of 40.3 months. Nineteen patients retained the original SKMEP, and the mean LLD was 4.3 cm (range, 0-10 cm). One case each of Henderson type 1B, type 2A, type 2B, and type 5B failures was observed. Knee subluxation occurred in two cases. Although a slight laxity of the knee was identified on physical examination, the average Musculoskeletal Tumor Society 93(MSTS93) functional score was 84.5% (range, 57-97%). The estimated implant survival was 70.5% at 5 years.

CONCLUSION

 This was the largest retrospective study reporting the application of SKMEP in bone sarcoma patients. For selected skeletally immature bone sarcoma patients, SKMEP is an option with satisfactory functional outcomes and survival rates. However, heightening pads or shoes to compensate the LLD were indispensable before subsequent LLD was adjusted by further operation(s).

Long-term outcomes of non-invasive expandable endoprostheses for primary malignant tumors around the knee in skeletally-immature patients

INTRODUCTION

Expandable endoprostheses are used to restore limb function and compensate for the sacrifice physis involved in carcinologic resection. Long-term outcomes of the last generation of knee "non-invasive" expandable endoprostheses are required. Objectives were to report on oncologic results of bone sarcoma resection around the knee with expandable endoprosthesis reconstruction and to compare the surgical outcomes of the "non-invasive" expandable endoprostheses used in our department.

MATERIALS AND METHODS

Retrospective study that included all children with bone sarcoma around the knee that underwent tumor resection reconstructed with non-invasive expandable prosthesis. Phenix-Repiphysis was used from 1994 to 2008 followed by Stanmore JTS non-invasive from 2008 to 2016. Survival and complications were recorded. Functional outcomes included Musculoskeletal Tumor Society (MSTS) score, knee range of motion, lower limb discrepancy (LLD).

RESULTS

Forty children (Sex Ratio = 1) aged a mean 8.8 years (range, 5.6-13.8) at surgery were included in the study. There were 36 osteosarcoma and 4 Ewing sarcoma that involved 33 distal femur and 7 proximal tibia. Cohort (n = 40) consisted of 28 Phenix-Repiphysis and 12 Stanmore with a mean follow-up of 9.8 ± 5.8 years and 6.1 ± 3.1 years, respectively. Postoperative infection rate was 7.5% in the cohort (3 Repiphysis). Functional results were significantly better in the Stanmore group with a mean MSTS of 87.6 ± 5.4% and knee flexion of 112 ± 38°. At last follow-up, implant survival was 100% in Stanmore group, whereas all living Phenix-Repiphysis were explanted. Mechanical failure was the primary cause for revision of Phenix-Repiphysis. Limb length equality was noted in 79% patients with Phenix-Repiphysis and 84% with Stanmore at last follow-up.

CONCLUSION

Chemotherapy and limb-salvage surgery yield good oncologic outcomes. Expandable endoprostheses are effective in maintaining satisfactory function and lower limb equality. With improvements made in the last generation of "non-invasive" prostheses, implants' survival has been substantially lengthened.

Management of Primary Aggressive Tumors of the Knee

Primary bone sarcomas and aggressive benign bone tumors are relatively rare. It is essential to recognize features that are concerning for these aggressive tumors based on a patient's history, physical exam, and radiographs. Physicians and other health care providers should have a high suspicion for these tumors and promptly refer these patients to orthopaedic oncologists. A multidisciplinary, team-based approach is required to obtain an accurate diagnosis and provide comprehensive care. This review discussed the appropriate work-up, biopsy principles, relevant peri-operative medical management, and surgical treatment options for patients with aggressive primary bone tumors around the knee. Primary bone sarcomas (osteosarcoma and chondrosarcoma) and aggressive benign bone tumors (giant cell tumor, chondroblastoma, and chondromyxoid fibroma) that have a predilection to the distal femur and proximal tibia are the focus of this review.

Long-term follow-up of children treated with the Repiphysis expandable prosthesis for lower extremity bone sarcoma

Expandable endoprostheses provide a limb salvage option for skeletally immature patients with bone sarcoma of the lower extremities. Initial reports of the Repiphysis prosthesis were encouraging; however, medium-term follow-up revealed high complication rates. We report on the long-term follow-up of a cohort of patients treated with the Repiphysis prosthesis. Eleven patients were included in the study. Data collected included sex, age at surgery, duration of follow-up, site of disease, histologic diagnosis, number of lengthening sessions, amount lengthened, postoperative complications, endoprosthetic failure, mode of endoprosthetic failure, duration from index surgery to failure and to revision, type of revision surgery and final limb-length discrepancy. The average duration of follow-up from the time of surgery was 180 months (range, 144-215 months). Fifteen Repiphysis implants were used in 11 patients. All implants failed with an average time from surgery to failure of 36 months (range, 3-72 months). Twenty-four complications were observed: one wound dehiscence, two deep infections, 18 mechanical failures, implant collapse with destruction of proximal tibia epiphysis in two and one periprosthetic proximal femur fracture with dislodgement of the stem. Despite being an option for limb salvage, the Repiphysis prosthesis has a high rate of mechanical failure and need for revision, similar to other expandable implants. The authors, therefore, recommend full disclosure of the potential short- and long-term complications and need for revision, as well as alternative treatment options if their use is considered. Level of evidence: IV (Therapeutic).

Rotationplasty Salvage Procedure as an Effective Alternative to Femoral Amputation in an Adult With a History of Osteosarcoma: A Case Report and Review

Rotationplasty or Borggreve-Van Ness surgery is lower limb salvage surgery, indicated mainly in the management of femoral bone sarcoma and congenital femur malformations in children. It can also be an interesting surgery option for managing chronic osteoarticular infections, or in cases of non union when curative therapy is no longer an option, as an alternative to femoral amputation. The principle of this surgery is to remove the affected knee and to apply a rotation of 180° to the distal part of the lower limb in order to give the ankle the function of a neo-knee. With the help of an adapted prosthesis, the aim is to allow patients to resume their social and professional activities by keeping most of their lower limb, thus avoiding the known complications of amputation (ghost limb pain, proprioceptive deficit, psychological disorders). Nevertheless, this surgery is complex and exceptional, with vascular, infectious, and psychological risks - the chimeric aspect of the lower limb may cause significant ill-being for the patient. This article reports the case of a 38-year-old patient consulting for management of a complex septic distal femoral non-union following osteosarcoma considered as being in remission. The patient underwent rotationplasty surgery on his left lower limb, with very good functional results and no surgical revision to date. In light of this particular case, we propose a didactic overview of the literature data concerning this surgery, especially in adulthood.

Frequency and reason for reoperation following non-invasive expandable endoprostheses: A systematic review

•

Implant failure is the most common reason for revision of growing prostheses.

•

Maximum prosthesis growth with a residual LLD is the most common mode of failure.

•

Functional outcomes are good, but 1/ 5 patients have a persistent LLD over 2 cm.

Background

Non-invasive expandable endoprostheses (NIEPR) utilize an external electromagnetic field to drive an innate mechanical gearbox. This lengthens the extremity following oncological resections in children with a predicted limb length discrepancy (LLD), facilitating limb-salvage. This review was conducted to assess NIEPR implant survival rates and identify modes of implant failure unique to these prostheses.

Methods

Medline, EMBASE and the Cochrane Library databases were searched for all manuscripts evaluating implant survival of NIEPRs implanted into skeletally immature patients following resection of extremity sarcomas. Minimum follow-up of 12 months or implant failure was required for inclusion. Failures were classified using the latest ISOLS classification and exact implant-specific failure modality was also identified.

Results

19 studies met inclusion criteria. Mean age was 10.0 years (7.7 – 11.4 years). The most common locations for NIEPR implantation were the distal femur (343, 76.7%) and proximal tibia (53, 119%). Mean follow-up was 65.3 months (19.4 – 163 months). The overall implant revision rate was 46.2% (0 – 100%); implant specific revisions included maximal prosthesis lengthening with persistent LLD (10.4%), failed extension mechanism (6.1%), implant fracture (7.7%), hinge fracture (1.4%) and bushing wear (0.9%). Persistent clinically significant (>20 mm) LLD at final follow-up was present in 19.2% (0 – 50%) of patients. The mean MSTS score was 85.1% (66.7–96.3%) at final follow-up.

Conclusion

Implant-related failures are the most common reason for NIEPR revision. Implant reliability appears to be improved with current designs. A sub-classification to the current classification system based on implant-specific failures for NIEPRs is proposed.

Lower Limb Reconstruction Using Tibial Strut Autograft after Resection of Primary Malignant Bone Tumors in Skeletally Immature Patients

Background

Reconstruction of large bone defects in skeletally immature patients remains a surgical challenge. We report the long-term clinical outcomes of a novel surgical technique for lower limb reconstruction using the tibia as a strut autograft following resection of primary malignant bone tumors in skeletally immature patients.

Methods

We retrospectively reviewed the medical records of six patients diagnosed with lower limb primary bone sarcoma. All patients underwent tumor resection and reconstruction using tibial strut autograft. The radiological and clinical outcomes including complications at the recipient and donor sites were assessed.

Results

The mean age at presentation was ten years (range 6-15 years). Two cases had osteosarcoma and four had Ewing sarcoma. The mean length of the resected tumor and tibial autografts were 20.83 and 19.33 cm respectively. Union at both ends was achieved in five grafts while one graft achieved union only at the distal end. The mean time for union of the proximal and distal junctions was 4 and 8.8 months respectively. The mean follow-up period was 8.4 years (range 14 months-20 years). One patient developed a foot drop, and three patients underwent subsequent joint arthrodesis (2 knees and 1 ankle). The mean musculoskeletal tumor society functional score was 80.8%. Two patients had clinically significant leg-length discrepancy that needs further lengthening procedure. Four patients survived with no evidence of disease and two patients died due to their primary oncologic disease. All donor sites regenerated, with the earliest signs of new bone formation at (2-4) weeks post-operatively.

Conclusion

Reconstruction using non-vascularized‎ tibia strut autograft after resection of primary malignant lower limb bone tumors can be a viable alternative method for reconstructing large bone defects in the immature skeleton.

Biology and technology in the surgical treatment of malignant bone tumours in children and adolescents, with a special note on the very young

PURPOSE

The main challenge in reconstruction after malignant bone tumour resection in young children remains how and when growth-plates can be preserved and which options remain if impossible.

METHODS

We describe different strategies to assure best possible long-term function for young children undergoing resection of malignant bone tumours.

RESULTS

Different resources are available to treat children with malignant bones tumours: a) preoperative planning simulates scenarios for tumour resection and limb reconstruction, facilitating decision-making for surgical and reconstructive techniques in individual patients; b) allograft reconstruction offers bone-stock preservation for future needs. Most allografts are intact at long-term follow-up, but limb-length inequalities and corrective/revision surgery are common in young patients; c) free vascularized fibula can be used as stand-alone reconstruction, vascularized augmentation of structural allograft or devitalized autograft. Longitudinal growth and joint remodelling potential can be preserved, if transferred with vascularized proximal physis; d) epiphysiolysis before resection with continuous physeal distraction provides safe resection margins and maintains growth-plate and epiphysis; e) 3D printing may facilitate joint salvage by reconstruction with patient-specific instruments. Very short stems can be created for fixation in (epi-)metaphysis, preserving native joints; f) growing endoprosthesis can provide for remaining growth after resection of epi-metaphyseal tumours. At ten-year follow-up, limb survival was 89%, but multiple surgeries are often required; g) rotationplasty and amputation should be considered if limb salvage is impossible and/or would result in decreased function and quality of life.

CONCLUSION

Several biological and technological reconstruction options must be merged and used to yield best outcomes when treating young children with malignant bone tumours.

LEVEL OF EVIDENCE

Level V Expert opinion.

Osteofibrous dysplasia and adamantinoma: A summary of diagnostic challenges and surgical techniques

Osteofibrous dysplasia is an indolent benign fibro-osseous tumor, while adamantinoma is a locally aggressive biphasic malignancy with epithelial and fibro-osseous components. Predominantly arising in the tibial diaphysis of children and young adults, both tumors are resistant to chemotherapy and radiation. Wide surgical resection is regarded as the mainstay of therapy for adamantinoma, and limb-salvage reconstructive procedures can achieve good functional outcomes, albeit with non-negligible rates of complications. This review discusses emerging advances in the pathogenesis, histogenesis, and diagnosis of these entities and presents advantages and limitations of the most common surgical techniques used for their management.

Safety of a Noninvasive Expandable Electromagnetic Prosthesis with an In Situ Ventricular Assist Device: A Case Report

CASE

An 8-year-old girl was diagnosed with osteosarcoma of the distal femur. She underwent chemotherapy and wide resection with implantation of a noninvasive electromagnetic expandable distal femur prosthesis. Ninety-three days after chemotherapy, she developed anthracycline-induced cardiomyopathy with heart failure for which a ventricular assist device was placed. Device compatibility was tested, and she was successfully lengthened.

CONCLUSION

Expandable prostheses allow limb length maintenance in skeletally immature patients who undergo limb salvage. Chemotherapy for osteosarcoma involves anthracyclines with a dose-dependent side effect of cardiotoxicity. Patients can be successfully and safely lengthened with expandable electromagnetic prostheses with in situ ventricular assist devices.

Current Status of Management and Outcome for Patients with Ewing Sarcoma

Ewing sarcoma is the second most common bone sarcoma in children after osteosarcoma. It is a very aggressive malignancy for which systemic treatment has greatly improved outcome for patients with localized disease, who now see survival rates of over 70%. However, for the quarter of patients presenting with metastatic disease, survival is still dismal with less than 30% of patients surviving past 5 years. Patients with disease relapse, local or distant, face an even poorer prognosis with an event-free 5-year survival rate of only 10%. Unfortunately, Ewing sarcoma patients have not yet seen the benefit of recent years' technical achievements such as next-generation sequencing, which have enabled researchers to study biological systems at a level never seen before. In spite of large multinational studies, treatment of Ewing sarcoma relies entirely on chemotherapeutic agents that have been largely unchanged for decades. As many promising modern therapies, including monoclonal antibodies, small molecules, and immunotherapy, have been disappointing to date, there is no clear candidate as to which drug should be investigated in the next large-scale clinical trial. However, the mechanisms driving tumor development in Ewing sarcoma are slowly unfolding. New entities of Ewing-like tumors, with fusion transcripts that are related to the oncogenic EWSR1-FLI1 fusion seen in the majority of Ewing tumors, are being mapped. These tumors, although sharing much of the same morphologic features as classic Ewing sarcoma, behave differently and may require a different treatment. There are also controversies regarding local treatment of Ewing sarcoma. The radiosensitive nature of the disease and the tendency for Ewing sarcoma to arise in the axial skeleton make local treatment very challenging. Surgical treatment and radiotherapy have their pros and cons, which may give rise to different treatment strategies in different centers around the world. This review article discusses some of these controversies and reproduces the highlights from recent publications with regard to diagnostics, systemic treatment, and surgical treatment of Ewing sarcoma.

Custom-Made 3D-Printed Implants as Novel Approach to Reconstructive Surgery after Oncologic Resection in Pediatric Patients

Recently, custom-made 3D-printed prostheses have been introduced for limb salvage surgery in adult patients, but their use has not been described in pediatric patients. A series of 11 pediatric patients (mean age 10.8 years; range 2-13) with skeletal tumors treated with custom-made implants for the reconstruction of bony defects is described. Patients were followed up every 3 months. Functional results were evaluated by the Musculoskeletal Tumor Society Score (MSTS) for upper and lower limbs. The mean follow-up was 25.7 months (range 14-44). Three patients died after a mean of 19.3 months postoperatively-two because of disease progression and the other from a previous malignancy. Three patients experienced complications related to soft tissues. One patient required device removal, debridement, and antibiotic pearls for postoperative infection. Partial osseointegration between grafts and host bone was observed within a mean of 4 months. At the final follow-up, mean MSTS score was 75%. 3D prostheses may yield biological advantages due to possible integration with the host bone and also through the use of vascularized flaps. Further research is warranted.

Epiphysis Salvage Reconstruction and Associated Complications Following Tumor Resections in Skeletally Immature Patients

The purpose of this study was to discuss the epiphysis salvage reconstruction procedure outcomes and complications in skeletally immature patients. The study included 12 patients with pediatric malignant tumors (osteosarcoma, Ewing's sarcoma) located close to the epiphysis, who underwent epiphyseal-preservation surgery with vascularized fibula in the plastic surgery and orthopedics and traumatology clinic between January 2008 and November 2018. The study was designed retrospectively. Neoadjuvant and adjuvant chemotherapy was administered to all patients. None of the patients received radiotherapy. Functional evaluation was assessed using the Musculoskeletal Tumor Society (MSTS) scoring system. The patients were followed up for a mean period of 51 (21‑115) months. The mean age of patients was 10.4 (range, 5 to 15) years. Union times in the target region (epiphyseal region) and diaphyseal region were reported separately. Accordingly, the mean total union time in the target region of all patients was 7.9 months (5‑11), and the mean total union time in the diaphyseal region was 6.5 months (5‑9). According to the MSTS grading system, the mean score of the patients was 27.50 (range, 21‑30). The mean operative time was 480 (390‑540) min, the mean intraoperative blood loss was 790 (580‑1100) cc, and the mean length of hospital stay was 6 (4‑17) days. Six patients had shortness, 5 patients had delayed union, 3 patients had angular deformity, and 2 patients had infection. Epiphyseal-preservation surgery may be an alternative to other techniques used for malignant tumors located close to the growth line in skeletally immature patients. Despite the fact that this technique has plenty of complications, many of them can be successfully treated with secondary operations without leaving sequelae.

Outcomes of Expandable Prostheses for Primary Bone Malignancies in Skeletally Immature Patients: A Systematic Review and Pooled Data Analysis

BACKGROUND

Osteosarcoma and other primary bone malignancies are relatively common in skeletally immature patients. Current literature features case series with disparate complication rates, making it difficult for surgeons to educate patients on outcomes after limb salvage with expandable prostheses. This study aims to provide an update on complication rates, mortality, and functional outcomes in patients who undergo limb salvage with expandable prostheses for primary bone malignancies.

METHODS

A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. An exhaustive PubMed/Medline and Cochrane search of peer-reviewed published literature from 1997 to 2017 was performed, yielding a total of 1350 studies. After multiple rounds of review for inclusion and exclusion criteria, 28 retrospective studies were included. All were level IV evidence of case series and retrospective studies. Overall, this included 634 total patients and 292 patients with individual patient data. The primary outcomes studied were complication rates, mortality, and Musculoskeletal Tumor Society (MSTS) functional score. Secondary outcomes included complication rate subtypes, number of lengthening procedures, mean amount lengthened, and prevalence of limb length discrepancies.

RESULTS

A total of 292 patients with individual patient data averaged 10.1 years at the surgery and had a mean follow-up of 67 months. Two hundred sixteen patients (74%) had tumors of the distal femur. MSTS scores averaged 80.3 and overall mortality was 22%. Patients with distal femur tumors averaged 4.4 lengthening procedures and 43 mm lengthened. Leg length discrepancy (LLD) was 36% overall, which increased with longer periods of follow-up (P<0.001). Overall complication and revision rate was 43%, increasing to 59% in patients with 5 to 10 years of follow-up, and 89% in patients with >10 years of follow-up. Minimally invasive prostheses had lower rates of complications than noninvasive prostheses (P=0.024), specifically mechanical complications (P=0.028), mostly because of increased rates of lengthening and device failure in the noninvasive models (21% vs. 4%, P=0.0004).

CONCLUSIONS

Despite its limitations, which include entirely heterogenous and retrospective case series data, this systematic review provides clinicians with pooled summary data representing the largest summary of outcomes after reconstruction with expandable prostheses to date. This analysis can assist surgeons to better understand and educate their patients and their families on functional outcomes, mortality, and complication rates after limb-sparing reconstruction with expandable prostheses for primary bone malignancies.

LEVEL OF EVIDENCE

Level IV-retrospective case series with pooled data.

Therapy management in bone sarcoma

Bone sarcomas are rare, representing only 0.2% of all diagnosed cancers. Incidence is higher in children and adolescents, but bone sarcomas are still numerically outnumbered by benign bone tumors in this patient cohort. This article summarizes the management of treatment for bone sarcomas. Systemic therapy, surgical therapy, and radiotherapy are presented. Osteosarcoma, chondrosarcoma, and Ewing sarcoma are among the most frequently occurring bone sarcomas in all age groups. In recent decades, multimodal treatment of these rare entities has increased disease-free survival for these patients. As malignant primary bone tumors are rare cancers, and since management is complex, the standard of treatment should be performed by reference centers. If possible, wide en-bloc resection of the bone sarcoma should be performed. The role of radiotherapy in osteosarcoma and chondrosarcoma is limited, but Ewing sarcoma is a radiation-responsive tumor. In primary bone sarcomas, the efficacy of chemotherapy varies according to histological type. Prognosis is poor in patients with osteosarcoma or Ewing’s sarcoma if surgery without neoaqdjuvant chemotherapy is performed. Despite advances in surgical, medical, and radiation therapy, few significant positive changes in overall survival have been observed in patients with these diseases in recent decades.

Joint-preservation surgery for pediatric osteosarcoma of the knee joint

The multi-disciplinary approach involving imaging, multi-agent chemotherapy, meticulous surgical procedures, and careful postoperative care has facilitated an increase in the use of limb-sparing surgery for pediatric osteosarcoma. Osteosarcoma usually occurs around the metaphysis of the distal femur or proximal tibia and needs wide excision with the adjacent joint and replacement by a megaprosthesis. The recent advancement in imaging modalities and surgical techniques supports joint-preservation surgery (JPS), involving the preservation of the adjacent epiphysis, for select patients following careful assessment of the tumor margins and precise tumor excision. An advantage of this surgery is that it maintains the adjacent joint and preserves the growth of the residual epiphysis, which provides excellent limb function. Various reconstruction options are available, including allograft, tumor-devitalized autograft, vascularized fibula graft, distraction osteogenesis, and custom-made implants. However, several complications are inevitable with these options, such as loosening, non-union at the host-graft junction, infection, fracture, implant loosening, breakage, deformity, limb-length discrepancy related to the reconstruction methods, or patient growth in pediatric osteosarcoma. Surgeons should fully understand the advantages and disadvantages of this procedure. In this review, we discuss the concept of JPS, types of reconstruction methods, and current treatment outcomes. It is our opinion that the further analysis by multi-institutional setting is necessary to clarify long-term outcomes and establish global guidelines on the indications and surgical procedure for JPS.

Extendable Endoprostheses in Skeletally Immature Patients: A Study of 124 Children Surviving More Than 10 Years After Resection of Bone Sarcomas

BACKGROUND

Extendable endoprostheses are used to reconstruct segmental defects following resection of bone sarcomas in skeletally immature patients. However, there remains a paucity of studies with regard to long-term outcomes.

METHODS

We retrospectively reviewed 124 skeletally immature children who underwent an extendable endoprosthetic replacement and survived more than 10 years after the surgical procedures. Anatomical sites included the distal part of the femur (n = 66), the proximal part of the femur (n = 13), the proximal part of the tibia (n = 29), and the proximal part of the humerus (n = 16). Complications and implant survival were classified according to the modified Henderson criteria.

RESULTS

The mean follow-up was 24 years (range, 10 to 36 years). The mean age at the time of the extendable endoprosthetic replacement was 9 years (range, 2 to 16 years). All patients had reached skeletal maturity at the last follow-up. The 10-year endoprosthetic failure-free survival rate was 28%. A total of 243 complications occurred in 90% of patients; these complications were most frequently related to soft-tissue problems (27% of complications). The incidence of and cumulative survival with respect to each failure mode varied between anatomical sites. Soft-tissue failures occurred most frequently in the proximal part of the femur (77%; p = 0.003), and the distal part of the femur was the most frequent site of aseptic loosening (52%; p = 0.014) and structural failure (55%; p = 0.001). Excluding lengthening procedures, 105 patients (85%) underwent an additional surgical procedure, with a mean of 2.7 surgical procedures per patient (range, 0 to 7 surgical procedures per patient). The mean limb-length discrepancy at the final follow-up was 1 cm (range, 0 to 9 cm). Limb salvage was achieved in 113 patients (91%). The mean Musculoskeletal Tumor Society functional score (the percentage of a total score of 30 points) was 82% (range, 40% to 100%) in 115 patients with available data at the last follow-up.

CONCLUSIONS

Extendable endoprostheses are associated with a high complication rate and a need for additional surgical procedures over time. Despite this, successful limb salvage with reasonable function and small limb-length discrepancy is achievable in the long term. Our study provides benchmark data for individual anatomical sites for further improvements of outcomes.

LEVEL OF EVIDENCE

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

[Current results of tumour endoprosthetics in adolescents and adults]

BACKGROUND

The majority of osteoarticular defects after tumor resection in adolescent and adult patients are reconstructed using megaendoprosthetic implants. However, even infant and pre-teen children undergo reconstruction of defects using so-called growing prostheses with an increasing frequency.

OBJECTIVES

Presentation of current techniques, outcomes and the most common complications of megaendoprosthetic reconstruction following tumour resection.

METHODS

Selective literature review and discussion of current concepts and knowledge in megaendoprosthetic reconstruction against personal experience and treatment strategies.

RESULTS

Megaendoprosthetic reconstructions achieve good functional results and long-term limb salvage (ca. 90% of cases) in adolescent and adult patients. Still, periprosthetic infection and mechanical failure of joint components are among the most common complications observed. In infant and pre-teen children treated by reconstruction using a growing prosthesis, mandatory maintenance operations-in the process of elongating the implant-must also be considered when assessing complication risks.

CONCLUSIONS

Megaendoprosthetic reconstructions of osteoarticular defects are a standard procedure in adolescent and adult patients. Despite a substantial complication rate, limb salvage is achieved in a majority of patients. When using growing prostheses in younger children, one needs to be aware of additional servicing procedures that occur independently of those arising from complications.

Prognostic scoring system for osteosarcoma using network-regularized high-dimensional Cox-regression analysis and potential therapeutic targets

With the recent emphasis on the importance of personalized genomic medicine, studies have performed prognostic stratification using gene signatures in cancers. However, these studies have not considered gene networks with clinical data. Therefore, this study aimed to develop a novel prognostic score using grouped variable selection for patients with osteosarcoma. We assessed messenger RNA (mRNA) expression and clinical data from Gene Expression Omnibus to develop a novel prognostic scoring system for patients with osteosarcoma. Variable selection using Network-Regularized high-dimensional Cox-regression analysis with information regarding gene networks obtained from six large pathway databases was performed. We determined the risk score on the linear combination of regression coefficients and mRNA expression values. Log-rank test, UNO's c-index, and area under the curve (AUC) values were determined to evaluate the discriminatory power between the low- and high-risk groups. A recently reported next-generation Connectivity Map was used to identify future therapeutic targets for osteosarcoma. Our novel model had significantly high discriminatory power in predicting overall survival. An optimal c-index of 0.967 was obtained and time-dependent receiver operating characteristic analysis revealed an acceptable predictive value of AUC between 0.953 and 1.000. Knockdown of BACE2 or ING2 and linifanib treatment may improve the prognosis of patients with osteosarcoma. Herein, this novel prognostic scoring system would not only facilitate a more accurate prediction of patient prognosis, but also contribute to the selection of suitable therapeutic alternatives for osteosarcoma patients.

Malignant distal femur tumors management in children, low cost innovations with affordable care in a tertiary care hospital, a cross sectional study

INTRODUCTION

Malignant musculoskeletal tumors in children are mostly comprised of Osteosarcoma and Ewing's sarcoma and distal femur is the most common site for primary bone tumors. This study examined the surgical management outcomes of pediatric patients (<18 years) presented in our setup with malignant distal femur tumors.

METHODOLOGY

We retrospectively reviewed the medical records of patients diagnosed with malignant sarcomas of distal femur and younger than 18 years of age who underwent limb salvage surgery during June 2009-June2017.

RESULTS

There were 31 pediatric patients who had distal femur malignant tumors and out of them 20 patients were selected who underwent limb salvage as a primary surgery. The mean age (range) of patients was 11.90 (6-17) years. Seventeen had osteosarcoma and three had Ewing's sarcoma. In surgery all patients were offered reconstruction. Post-operative complications were observed in (50%) patients while other 50% patients had no complications. Wound infection, flap necrosis, broken plates with non-union and recurrence of disease were the reported complications. Revision surgery was performed in 10 patients out of 20 patients.

CONCLUSION

Salvage was the primary option in our surgery and revision surgery was performed in the cases due to complications. Small sample size was the limitation of the study.

Functional and Surgical Outcomes After Endoprosthetic Reconstruction With Expandable Prostheses in Children: A Systematic Review

Treatment of bone sarcomas in children is associated with wide tumor re-section and segmental reconstruction. The optimal surgical approach is still under debate in the literature. During the past decade, the application of expandable prostheses has gained remarkable attention because it improves patients' appearance and allows limb growth preventing leg length discrepancy. A systematic review of the literature was performed to identify studies focusing on the functional and surgical outcomes of the application of expandable endoprostheses. [Orthopedics. 2019; 42(4):184-190.].

[Growing prostheses after sarcoma resection in children and adolescents]

BACKGROUND

Growing prostheses are regarded as a valuable alternative to amputation and rotationplasty for the treatment of primary malignant bone and soft-tissue sarcomas in childhood. During the last three decades different devices have been introduced and technically improved from invasively to non-invasively extendable prostheses.

THE CURRENT SITUATION OF STUDIES

Despite the long period, only 21 peer-reviewed publications could be detected containing relevant numbers and results. In these papers, 590 patients with mean follow-up times of 81.1 months were reported who had been fitted with growing prostheses at the age of 12.6 years. Besides satisfactory functional results (78.3 out of 100 MSTS points) there was a high complication rate of 27.3% infections and 22.4% mechanical failure.

COMPLICATIONS

This increasing risk of infection over a long follow-up period, represents the biggest drawback of this method and, therefore, needs to be discussed extensively with the patients and parents when considering this procedure as an alternative to ablative surgery.

Current review of surgical management options for extremity bone sarcomas

Modern surgical management of extremity bone sarcomas is governed by limb-sparing surgery combined with adjuvant and neoadjuvant chemotherapy.

All the resection and reconstruction techniques have to achieve oncologic excision margins, with survival rates and functional results superior to amputation.

The main reconstruction techniques of bone defects resulted after resection are: modular endoprosthetic reconstruction; bone graft reconstruction; bone transport; resection arthrodesis; and rotationplasty.

Oncologic resection and modular endoprosthetic reconstruction are the generally approved surgical options adopted for the majority of cases in major specialized bone sarcoma centres.

Good basic principles, efficient multidisciplinary approach and sustained research in the field can provide a better future for the challenge posed by extremity bone sarcoma treatment.

Cite this article: EFORT Open Rev 2019;4:174-182. DOI: 10.1302/2058-5241.4.180048

High complication rate after extendible endoprosthetic replacement of the proximal tibia: a retrospective study of 42 consecutive children

Background and purpose - The long-term outcome of reconstruction with extendible prostheses after resection of tumors the proximal tibia in children is unknown. We investigated the functional outcome, complication rate and final limb salvage rate after this procedure. Patients and methods - 42 children who had a primary extendible replacement of the proximal tibia for bone tumor with a Stanmore implant between 1992 and 2013 were identified in the department's database. All notes were reviewed to identify the oncological and functional outcomes, the incidence of complications and the rate of amputation. 20 children were alive at final follow-up. Median follow-up time was 6 years and minimum follow-up for surviving patients was 3 years. Results - The overall limb salvage rate was 35/42; amputation was needed in 7 children. 15 implants were revised with a new implant. The Musculoskeletal Tumor Society Score was 73% (40-93) at final follow-up. The overall complication rate was 32/42. Soft tissue problems were the most common mode of complication, noted in 15 children, whereas structural failure and infection occurred in 12 children each. Use of prostheses with non-invasive lengthening was associated with a higher infection rate as compared with conventional ones (4/6 vs. 8/36) and inferior limb survival. Interpretation - Extendible replacements of the proximal tibia allow for limb salvage and satisfactory late functional outcome but have a high rate of complications. The use of non-invasive lengthening implants has not shown any benefit compared with conventional designs and is, rather, associated with higher risk for infection and amputation.

What Are the Complications of Allograft Reconstructions for Sarcoma Resection in Children Younger Than 10 Years at Long-term Followup?

BACKGROUND

Preservation of limb function after resection of malignant bone tumors in skeletally immature children is challenging. Resection of bone sarcomas and reconstruction with an allograft in patients younger than 10 years old is one reconstructive alternative. However, long-term studies analyzing late complications and limb length discrepancy at skeletal maturity are scarce; this information would be important, because growth potential is altered in these patients owing to the loss of one physis during tumor resection.

QUESTIONS/PURPOSES

At a minimum followup of 10 years after reconstructions in children younger than 10 years of age at the time of reconstruction, we asked what is (1) the limb length discrepancy at skeletal maturity and how was it managed; (2) the risk of amputation; (3) the risk of allograft removal; and (4) the risk of second surgery resulting from complications?

METHODS

Between 1994 and 2006, we performed 22 bone allografts after bone sarcoma resections in children younger than 10 years of age. Of those, none were lost to followup before the minimum followup of 10 years was reached, and an additional six had died of disease (of whom three died since our last report on this group of patients), leaving 16 patients whom we studied here. Followup on these patients was at a mean of 13.5 years (range, 10-22 years). During the period in question, no other treatments (such as extendible prostheses, amputations, etc) were used. The mean age at the time of the original surgery was 7 years (range, 2-10 years), and the mean age of the 16 alive patients at last followup was 20 years (range, 15-28 years). This series included 10 boys and six girls with 14 osteosarcomas and two Ewing sarcomas. Ten reconstructions were performed with an intercalary allograft and six with an osteoarticular allograft. The growth plate was uninvolved in three patients, whereas in the remaining 13, the growth plate was included in the resection (seven intercalary and six osteoarticular allografts). Limb length discrepancy at skeletal maturity was measured with full-length standing radiographs, and data were collected by retrospective study of a longitudinally maintained institutional database. The risk of amputation, allograft removal, and secondary surgery resulting from a complication was calculated by a competing-risk analysis method.

RESULTS

We observed no limb length discrepancy at skeletal maturity in the three patients with intercalary resections in whom we preserved the physes on both sides of the joint (two femurs and one tibia); however, one patient developed malalignment that was treated with corrective osteotomy of the tibia. The remaining 13 patients developed limb length discrepancy as a result of loss of one physis. Seven patients (four femurs, two tibias, and one humerus) developed shortening of ≤ 3 cm (mean, 2.4 cm; range, 1-3 cm) and no lengthening was performed. Six patients developed > 3 cm of limb discrepancy at skeletal maturity (all distal femoral reconstructions). In four patients this was treated with femoral lengthening, whereas two declined this procedure (each with 6 cm of shortening). In the four patients who had a lengthening procedure, one patient had a final discrepancy of 4 cm, whereas the other three had equal limb lengths at followup. The risk of amputation was 4% (95% confidence interval [CI], 0-15) and none occurred since our previous report. The risk of allograft removal was 15% (95% CI, 1-29) and none occurred since our previous report on this group of patients. The risk of other operations resulting from a complication was 38% (95% CI, 19-57). Eleven patients underwent a second operation resulting from a complication (three local recurrences, five fractures, one infection, one nonunion, and one tibial deformity), of which three were performed since our last report on this group of patients.

CONCLUSIONS

Limb length inequalities and subsequent procedures to correct them were common in this small series of very young patients as were complications resulting in operative procedures, but overall most allografts remained in place at long-term followup. In skeletally immature children, bone allograft is one alternative among several that are available (such as rotationplasty and endoprosthesis), and future studies with long followup may be able to compare the available options with one another.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

The use of a non-invasive extendable prosthesis at the time of revision arthroplasty

Aims

The use of a noninvasive growing endoprosthesis in the management of primary bone tumours in children is well established. However, the efficacy of such a prosthesis in those requiring a revision procedure has yet to be established. The aim of this series was to present our results using extendable prostheses for the revision of previous endoprostheses.

Patients and Methods

All patients who had a noninvasive growing endoprosthesis inserted at the time of a revision procedure were identified from our database. A total of 21 patients (seven female patients, 14 male) with a mean age of 20.4 years (10 to 41) at the time of revision were included. The indications for revision were mechanical failure, trauma or infection with a residual leg-length discrepancy. The mean follow-up was 70 months (17 to 128). The mean shortening prior to revision was 44 mm (10 to 100). Lengthening was performed in all but one patient with a mean lengthening of 51 mm (5 to 140).

Results

The mean residual leg length discrepancy at final follow-up of 15 mm (1 to 35). Two patients developed a deep periprosthetic infection, of whom one required amputation to eradicate the infection; the other required two-stage revision. Implant survival according to Henderson criteria was 86% at two years and 72% at five years. When considering revision for any cause (including revision of the growing prosthesis to a non-growing prosthesis), revision-free implant survival was 75% at two years, but reduced to 55% at five years.

Conclusion

Our experience indicates that revision surgery using a noninvasive growing endoprosthesis is a successful option for improving leg length discrepancy and should be considered in patients with significant leg-length discrepancy requiring a revision procedure. Cite this article: Bone Joint J 2018;100-B:370-7.

When Do Orthopaedic Oncologists Consider the Implantation of Expandable Prostheses in Bone Sarcoma Patients?

Introduction

Indications discussed for the implantation of expandable prostheses in bone sarcoma patients are unclear. This survey aimed to analyse common practice with this implant type in orthopaedic oncology.

Methods

A web-based survey was sent to 98 orthopaedic oncology surgeons. Factors reported in literature to influence the decision on the implantation of a growing prosthesis were covered in individual questions and three case scenarios.

Results

The completion rate of the survey was 45% (n = 44). Twenty-seven of 44 surgeons (61%) had implanted between 1 and 15 expandable prostheses within three years. The minimum median patient age was 6.5 years, and 3–5 cm of predicted growth deficit was the minimum before implanting a growing prosthesis. One-third of surgeons do not use growth calculation methods. Two out of three surgeons would rather not implant a growing prosthesis in children with metastatic disease.

Conclusions

Our survey confirmed the literature with 3-4 cm as the minimum estimated growth deficit. The minimum age for the implantation of a growing prosthesis is approx. 6.6 years, and therefore the patients are younger than those reported in previous publications. One-quarter of orthopaedic surgeons do not use growing prostheses at all. It remains unclear whether growing prostheses are indicated in patients with metastatic disease.

Surgical and Functional Outcomes After Limb-Preservation Surgery for Tumor in Pediatric Patients: A Systematic Review

BACKGROUND

Limb-salvage surgery and segmental reconstruction for the treatment of lower extremity osseous tumors in the pediatric population have been described in the literature, but there is little consensus regarding the optimal surgical treatment for this patient population.

METHODS

A systematic review of the literature was performed to identify studies focusing on limb-salvage procedures in pediatric patients who were managed with one of three reconstructions with use of a metallic endoprosthesis, allograft, or allograft-prosthesis composite. Data were segregated according to the excised and reconstructed anatomical location (proximal part of the femur, total femur, distal part of the femur, proximal part of the tibia) and were collated to assess modes of failure and functional outcomes of each reconstruction type for each anatomic location.

RESULTS

Sixty articles met the inclusion criteria; all were Level-IV evidence, primarily consisting of small, retrospective case series. Infection was a primary mode of failure across all reconstruction types and locations, whereas allograft reconstructions were susceptible to structural failure as well. The rate of failure in the pediatric population correlated well with previously published results for adults. The incidence of subsequent amputation was lower in the pediatric population (5.2%) than has been reported in adults (9.5%) (p = 0.013). Meaningful growth of expandable metallic endoprostheses was reported in the literature, with an overall rate of leg-length discrepancy of 13.4% being noted at the time of the latest follow-up. The Musculoskeletal Tumor Society (MSTS) questionnaire was the most consistently used outcome measure in the literature, with average scores ranging from 71.0% to 86.8%, depending on reconstruction type and anatomic location.

CONCLUSIONS

The current state of the literature detailing the surgical and functional outcomes of segmental reconstruction for the treatment of pediatric bone tumors is limited to Level-IV evidence and is complicated by under-segregation of the data by age and anatomical location of the reconstruction. Despite these limitations, pediatric limb-salvage surgery demonstrates satisfactory initial surgical and functional outcomes.

LEVEL OF EVIDENCE

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

What are the Oncologic and Functional Outcomes After Joint Salvage Resections for Juxtaarticular Osteosarcoma About the Knee?

BACKGROUND

Joint salvage surgery for patients with juxtaarticular osteosarcoma remains challenging, especially when the tumor invades the epiphysis. Because patients are surviving longer with current chemotherapy regimens, it is advantageous to retain native joints if possible, especially in young patients. However, the results using joint-preserving tumor resections in this context have not been well characterized.

QUESTIONS/PURPOSES

(1) What are the functional outcomes after limb salvage surgery at a minimum of 3 years? (2) What are the oncologic outcomes? (3) Is joint salvage surgery for epiphyseal tumors associated with an increased risk of local recurrence compared with metaphyseal tumors not invading the epiphysis? (4) What are the complications associated with joint salvage surgery?

METHODS

Between 2004 and 2013, we treated 117 patients with juxtaarticular osteosarcoma; of those, 43 (38%) were treated with joint salvage surgery, and 41 (95%) of the 43 patients are included in our study. The other two (5%) were lost to followup before 3 years (mean, 4.4 years; range, 3-11 years,). During the period in question, we generally performed joint salvage surgery in these patients when they had a favorable response to chemotherapy, did not have a pathologic fracture or extrusion of the tumor into the joint, and did not have a whole-epiphyseal osteolytic lesion, a large mass, or obvious neurovascular involvement. This report is a followup of an earlier study; the current study includes an additional nine patients, and additional followup of a mean of 19 months for the patients included in the earlier report. We ascertained overall survival and survival free from local recurrence which was estimated using the Kaplan-Meier method, functional status of the limb which was evaluated using the Musculoskeletal Tumor Society (MSTS)-93 scoring system, and recorded reconstructive complications including infection, fracture, skin necrosis, and nonunion. We compared oncologic and functional outcomes between patients with (n = 28) and without tumor extension to epiphysis (n =13). We also compared oncologic and functional outcomes among patients with different adjuvant treatments including microwave ablation (n = 11), cryoablation (n = 12), and navigation-assisted osteotomy (n = 5). Complications were tallied using records from our institutional database.

RESULTS

The overall Kaplan-Mayer survival rate was 82% (95% CI, 104-128 months) at 5 years. The overall Kaplan-Meier survivorship from local recurrence was 91% at 5 years (95% CI, 115-133 months). Three patients had a local recurrence, but none had local recurrence in or close to the remaining epiphysis. The MSTS scores ranged from 22 to 30 points, with a median of 28. There were no differences in survival rate, local recurrence, or MSTS scores between patients with a tumor that did not invade the epiphysis and those in whom the tumor did invade the epiphysis. There were differences in MSTS scores among patients with epiphyseal tumor extension in which different adjuvant techniques, including microwave ablation, cryoablation, and navigation-assisted osteotomy, were used. Additional surgical procedures were recorded for 10 patients (24%). Osteonecrosis of the residual epiphysis was detected 13 patients (31%).

CONCLUSIONS

Our findings suggest it is possible to salvage joints in selected patients with juxtaarticular osteosarcoma around the knee. The patients who have a favorable response to chemotherapy are the best candidates for this approach. Future studies might explore the role of adjuvant techniques of microwave ablation and cryoablation, particularly when the tumor invades the epiphysis, and whether resections can be facilitated with navigation.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Distraction osteogenesis reconstruction of large segmental bone defects after primary tumor resection: pitfalls and benefits

Successful cure is achieved in almost 70% of patients with primary bone sarcomas with currently available therapies. Some soft tissue sarcomas require wide bone resection in order to achieve appropriate margins for cure of disease, and patients undergoing these procedures need durable reconstruction. Biological reconstruction has been shown to provide patients with superior long-term results over other alternatives. Distraction osteogenesis is well studied in the correction of deformities as well as in addressing some congenital musculoskeletal pathologies. The use of this technique in tumor settings has been avoided by many surgeons for a multitude of concerns, including infection risk, potential tumor activation, and uncertainty regarding the effect of systemic therapy on the callus regenerate. We review the use of this reconstruction technique using cases from our institutional experience to illustrate its incorporation into the successful management of orthopedic oncology patients. Distraction osteogenesis is an effective method for reconstructing even large bony defects and is safe in the setting of systemic therapy. This technique has the potential to address some of the common problems associated with orthopedic oncology resection, such as infection and leg length discrepancy.

Megaprosthesis of the knee in tumor and revision surgery

The introduction of multidisciplinary approach with chemo and radiotherapy, the advances in surgical and the improvements of diagnostic techniques allowed limb salvage surgery in most cases of bone sarcomas instead of amputation. Modular megaprostheses are the most common method of reconstruction after segmental resection of the long bones in the extremities for their availability, immediate fixation, early weight bearing, good function. Despite the advances in materials and implant designs, these systems have an high incidence of complications. Aim of this study was to report the experience on mega-prostheses implanted around the knee in tumor and revision surgery to analyze: the most frequent used current systems, the problems of stems fixation, extensor mechanism reconstructions in proximal tibia resections and the preservation of growth of the lower extremity in children.

Megaprosthesis of the knee in tumor and revision surgery

The introduction of multidisciplinary approach with chemo and radiotherapy, the advances in surgical and the improvements of diagnostic techniques allowed limb salvage surgery in most cases of bone sarcomas instead of amputation. Modular megaprostheses are the most common method of reconstruction after segmental resection of the long bones in the extremities for their availability, immediate fixation, early weight bearing, good function. Despite the advances in materials and implant designs, these systems have an high incidence of complications. Aim of this study was to report the experience on mega-prostheses implanted around the knee in tumor and revision surgery to analyze: the most frequent used current systems, the problems of stems fixation, extensor mechanism reconstructions in proximal tibia resections and the preservation of growth of the lower extremity in children. (www.actabiomedica.it)

Surgical Innovation in Sarcoma Surgery

The field of orthopaedic oncology relies on innovative techniques to resect and reconstruct a bone or soft tissue tumour. This article reviews some of the most recent and important innovations in the field, including biological and implant reconstructions, together with computer-assisted surgery. It also looks at innovations in other fields of oncology to assess the impact and change that has been required by surgeons; topics including surgical margins, preoperative radiotherapy and future advances are discussed.