Factors Influencing Osseous Union Following Surgical Treatment of Bone Tumors with Use of the Capanna Technique

Case report: A left forearm mass with eccentric intramedullary ulnar destruction diagnosed as alveolar rhabdomyosarcoma and treated by wide resection and free vascularized fibular graft

Background

Alveolar Rhabdomyosarcoma is a profoundly malignant soft-tissue sarcoma that predominantly affects children and adolescents. However, the medical field lacks consensus regarding the optimal surgical approach to be undertaken in cases where this tumor causes local bone destruction in the upper limb.

Case description

A 17-year-old male presented a mass in his left forearm and CT and MRI indicated that the mass had penetrated the ulnar cortex and infiltrating the medulla, resulting in the formation of an eccentric trans-ventricular tumor focus. The sizable tumor affected the volar muscles of the forearm as well as the ulnar bone marrow, exerting pressure on the ulnar artery and vein. It was confirmed by needle biopsy that the mass is alveolar rhabdomyosarcoma. Following two courses of neoadjuvant chemotherapy, the tumor was widely excised en bloc. Autologous fibula with a vascular pedicle was utilized for reconstruction during the procedure. In the postoperative follow-up, no local recurrence of the tumor was observed. Furthermore, the patient retained satisfactory wrist flexion and pronation function in the left forearm.

Conclusions

Alveolar rhabdomyosarcoma is an uncommon and highly aggressive form of soft tissue sarcoma. Scientific management necessitates a multidisciplinary approach, combining chemotherapy with surgery. In cases where the tumor invaded into compartment of the bone, careful consideration should be given to the boundaries of tumor resection, the extent of osteotomy, and the approach to musculoskeletal reconstruction when designing the surgical plan. Through reporting our own case and thoroughly reviewing previous clinical experiences, we aim to provide valuable insights for the treatment of this particular disease.

Midterm Donor Site Morbidity After Vascularized Free Fibula Flap Harvesting

BACKGROUND

Vascularized fibula grafts (VFGs) have become one of the most preferred grafts for the reconstruction of bone defects. However, despite the many advantages over other graft options, recipient and donor site morbidities are also common. Donor site morbidity has been reported at rates ranging from 5% to 67%. The aim of this study was to present a single-center series examining the clinical, functional, and radiologic aspects of donor site morbidity following VFG harvesting.

METHODS

The study included 69 patients who underwent biological reconstruction with VFG for bone tumors, avascular necrosis of the femoral head, or bone defects after trauma. Patients were evaluated functionally, clinically, and radiologically for donor site morbidity.

RESULTS

Donor site morbidity was observed in 33 of 69 patients (48%). The most complications were sensation deficits around the feet and ankles (20 of 69; 29%). Knee laxity was more common in patients who underwent osteoarticular fibular resection (P = .006).

CONCLUSION

We found VFG to be an effective method for the reconstruction of large bone defects, but associated with a relatively high rate of complications. Complications requiring surgical intervention were rare and the majority of patients did not have long-term functional limitations.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Intercalary Resection of the Tibia for Primary Bone Tumors: Are Vascularized Fibula Autografts With or Without Allografts a Durable Reconstruction?

BACKGROUND

Reconstruction with vascularized fibula grafts (VFG) after intercalary resection of sarcoma may offer longevity by providing early graft-host union and fracture healing. The ability of the fibula to hypertrophy under mechanical stress, as well as vascularized bone in the area, may also be advantageous, given that soft tissues may be compromised because of resection, chemotherapy, or radiation therapy. VFG with a massive allograft combines the primary mechanical stability of the graft with the biological potential of the vascularized fibula; however, complications and the durability of this combined reconstruction are not well described.

QUESTIONS/PURPOSES

(1) What was the proportion of complications after reconstruction with VFG, with or without allografts? (2) What was the functional result after surgical treatment as assessed by the Musculoskeletal Tumor Society (MSTS) score? (3) What was the survivorship of these grafts free from revision and graft removal?

METHODS

Between 1988 and 2021, 219 patients were treated at our institution for a primary malignant or aggressive benign bone tumor of the tibia with en bloc resection. Of those, 54% (119 of 219) had proximal tibial tumors with epiphyseal involvement and were treated with either intra-articular resection and reconstruction with an osteoarticular allograft, allograft-prosthesis composite (APC), or modular prosthesis according to age, diagnosis, and preoperative or postoperative radiotherapy. Nine percent (20) of patients had distal tibial tumors that were treated with intra-articular resection and reconstruction with ankle arthrodesis using allogenic or autologous grafts, and 0.5% (1 patient) underwent total tibial resection for extensive tumoral involvement of the tibia and reconstruction with an APC. Thirty-six percent (79) of patients had a metadiaphyseal bone tumor of the tibia and were treated with intercalary joint-sparing resection. We routinely use reconstruction with VFG after intercalary tibial resection for primary malignant or aggressive benign bone tumors in patients with long life expectancy and high functional demands and in whom at least 1 cm of residual bone stock of the proximal or distal epiphysis can be preserved. By contrast, we routinely use intercalary massive allograft reconstruction in short resections or in patients with metastatic disease who do not have long life expectancy. We avoid VFG in patients with tibial bone metastasis, patients older than 70 years, or primary bone tumors in patients who may undergo postoperative radiotherapy; in these patients, we use alternative reconstructive methods such as intercalary prostheses, plate and cement, or intramedullary nailing with cement augmentation. According to the above-mentioned indications, 6% (5 of 79) of patients underwent massive allograft reconstruction because they were young and had intercalary resections shorter than 7 cm or had metastatic disease at diagnosis without long life expectancy, whereas 94% (74) of patients underwent VFG reconstruction. The median age at operation was 16 years (range 5 to 68 years). The diagnosis was high-grade osteosarcoma in 22 patients, Ewing sarcoma in 19, adamantinoma in 16, low-grade osteosarcoma in five, fibrosarcoma in three, malignant fibrous histiocytoma and Grade 2 chondrosarcoma in two, and malignant myoepitelioma, angiosarcoma of bone, malignant peripheral nerve sheath tumor of bone, squamous cell carcinoma secondary to chronic osteomyelitis, and desmoplastic fibroma in one patient each. Median follow-up was 12.3 years (range 2 to 35 years). The median tibial resection length was 15 cm (range 7 to 27 cm), and the median fibular resection length was 18 cm (range 10 to 29 cm). VFG was used with a massive allograft in 55 patients, alone in 12 patients, and combined with allogenic cortical bone struts in seven patients. We used VFG combined with a massive allograft in patients undergoing juxta-articular, joint-sparing resections that left less than 3 cm of residual epiphyseal bone, for intra-epiphyseal resections, or for long intercalary resections wherein the allograft can provide better mechanical stability. In these clinical situations, the combination of a VFG and massive allograft allows more stable fixation and better tendinous reattachment of the patellar tendon. VFG was used with cortical bone struts in distal tibia intercalary resections where the narrow diameter of the allograft did not allow concentric assembling with the fibula. Finally, VFG alone was often used after mid- or distal tibia intercalary resection in patients with critical soft tissue conditions because of previous surgery, in whom the combination with massive allograft would result in a bulkier reconstruction. We ascertained complications and MSTS scores by chart review, and survivorship free from revision and graft removal was calculated using the Kaplan-Meier estimator. In our study, however, the occurrence of death as a competing event was observed in a relatively low proportion of patients, and only occurred after the primary event of interest had already occurred. Considering the nature of our data, we did not consider death after the primary event of interest as a competing event.

RESULTS

In all, 49% (36 of 74) of patients experienced complications and underwent operative treatment. There were 45 complications in 36 patients. There was one instance of footdrop secondary to common peroneal nerve palsy, four wound problems, one acute vein thrombosis of the VFG pedicle and one necrosis of the skin island, two episodes of implant-related pain, 10 nonunions, six fractures, six deep infections, nine local recurrences, one Achilles tendon retraction, one varus deformity of the proximal tibia with postoperative tibial apophysis detachment, one knee osteoarthritis, and one hypometria. The median MSTS score was 30 (range 23 to 30); the MSTS score was assessed only in patients in whom the VFG was retained at the final clinical visit, although if we had considered those who had an amputation, the overall score would be lower. Revision-free survival of the reconstructions was 58% (95% confidence interval 47% to 70%) at 5 years, 52% (95% CI 41% to 65%) at 10 and 15 years, and 49% (95% CI 38% to 63%) at 20 and 30 years. Eight patients underwent VFG removal because of complications, with an overall reconstruction survival of 91% (95% CI 84% to 98%) at 5 years and 89% (95% CI 82% to 97%) at 10 to 30 years.

CONCLUSION

VFG, alone or combined with an allograft, could be considered in reconstructing a lower extremity after intercalary resections of the tibia for primary bone tumors, and it avoids the use of a large endoprosthesis. However, this procedure was associated with frequent, often severe complications during the first postoperative years and complication-free survival of 58% at 5 years. Nearly 10% of patients ultimately had an amputation. For patients whose reconstruction succeeded, the technique provides a durable reconstruction with good MSTS scores, and we believe it is useful for active patients with long life expectancy. Fractures, frequently observed in the first 5 years postoperatively, might be reduced using long-spanning plate fixation, and that appeared to be the case in our study. Nonbridging fixation can be an option in intraepiphyseal resection when a spanning plate cannot be used or in pediatric patients to enhance fibula hypertrophy and remodeling. We did not directly compare VFG with or without allografts to other reconstruction options, so the decision to use this approach should be made thoughtfully and only after considering the potential serious risks.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Adamantinoma of the Ulnar Shaft Reconstructed With a Vascularized Free Fibula

We describe a 36-year-old man with a long-standing diagnosis of ulnar fibrous dysplasia with associated fracture of the ulna. He presented with a growing and increasingly tender forearm mass and was diagnosed with adamantinoma of the ulna, for which he underwent wide resection of the ulnar diaphysis followed by reconstruction with a vascularized fibula autograft. This case serves to emphasize the importance of performing a stepwise workup for the diagnosis of osseous neoplasms even in cases with long-standing diagnoses. [Orthopedics. 2024;47(2):e102-e105.].

Advances in Virtual Cutting Guide and Stereotactic Navigation for Complex Tumor Resections of the Sacrum and Pelvis: Case Series with Short-Term Follow-Up

Primary malignancies of the sacrum and pelvis are aggressive in nature, and achieving negative margins is essential for preventing recurrence and improving survival after en bloc resections. However, these are particularly challenging interventions due to the complex anatomy and proximity to vital structures. Using virtual cutting guides to perform navigated osteotomies may be a reliable method for safely obtaining negative margins in complex tumor resections of the sacrum and pelvis. This study details the technique and presents short-term outcomes. Patients who underwent an en bloc tumor resection of the sacrum and/or pelvis using virtual cutting guides with a minimum follow-up of two years were retrospectively analyzed and included in this study. Preoperative computer-assisted design (CAD) was used to design osteotomies in each case. Segmentation, delineating the tumor from normal tissue, was performed by the senior author using preoperative CT scans and MRI. Working with a team of biomedical engineers, virtual surgical planning was performed to create osteotomy lines on the preoperative CT and overlaid onto the intraoperative CT. The pre-planned osteotomy lines were visualized as "virtual cutting guides" providing real-time stereotactic navigation. A precision ultrasound-powered cutting tool was then integrated into the navigation system and used to perform the osteotomies in each case. Six patients (mean age 52.2 ± 17.7 years, 2 males, 4 females) were included in this study. Negative margins were achieved in all patients with no intraoperative complications. Mean follow-up was 38.0 ± 6.5 months (range, 24.8-42.2). Mean operative time was 1229 min (range, 522-2063). Mean length of stay (LOS) was 18.7 ± 14.5 days. There were no cases of 30-day readmissions, 30-day reoperations, or 2-year mortality. One patient was complicated by flap necrosis, which was successfully treated with irrigation and debridement and primary closure. One patient had local tumor recurrence at final follow-up and two patients are currently undergoing treatment for metastatic disease. Using virtual cutting guides to perform navigated osteotomies is a safe technique that can facilitate complex tumor resections of the sacrum and pelvis.

Biological reconstruction of bone defect after resection of malignant bone tumor by allograft: a single-center retrospective cohort study

BACKGROUND

Allograft reconstruction following the resection of malignant bone tumors is associated with high rates of complications and failures. This study aimed to evaluate the efficacy and current problems of allograft reconstruction techniques to optimize treatment strategies at our center.

MATERIALS AND METHODS

Thirty-eight cases (16 men and 22 women), who were diagnosed with malignant bone tumors and had undergone allograft reconstruction, were recruited. Allograft was fixed by intramedullary nail, single steel plate, double plate, and intramedullary nail combined plate in 2, 4, 17, and 15 cases, respectively. Allograft union, local recurrence, and complications were assessed with clinical and radiological tests. Tumor grade was assessed using the Enneking staging of malignant bone tumors. Functional prognosis was evaluated by the Musculoskeletal Tumor Society (MSTS) scoring system.

RESULTS

Intercalary and osteoarticular reconstructions were performed in 32 and 6 cases, respectively. Six patients underwent reoperation related to allograft complications, four patients had local recurrence, and three patients with allograft fracture underwent allograft removal. A total of eight host-donor junctions showed nonunion, including seven cases (18.4%) in diaphysis and one case (3.1%) in metaphysis (p < 0.01). Host rejection and secondary osteoarthritis occurred in nine and two cases, respectively. No deep infection and internal fixation device fracture occurred. The overall allograft survival rate was 81.6%. Postoperative MSTS score of patients with allograft survival was 26.8 ± 2.9, indicating a significant improvement as compared to their preoperative function.

CONCLUSIONS

Allograft represents an excellent choice for intercalary bone defects after malignant bone tumor resection. Robust internal fixation protection across the whole length of the allograft is an important prerequisite for the survival of the allograft, while multidimensional osteotomy, intramedullary cement reinforcement, and pedicled muscle flap transfer can effectively improve the survival rate and healing rate of the allograft.

Factors affecting the incorporation of extracorporeally irradiated autograft for the treatment of bone tumours-a retrospective analysis from a tertiary referral centre

PURPOSE

Re-implantation of the tumor bearing autograft following extracorporeal radiation therapy (ECRT) has been established as an oncologically safe biological reconstruction technique following resection of bone sarcomas. However, factors affecting the ECRT graft-host bone incorporation have not been fully investigated. An insight into the factors that influence graft incorporation can circumvent the complications and increase graft survival.

METHODS

A total of 96 osteotomies in 48 patients with intercalary resections of primary extremity bone sarcomas (mean age 15.8 years, mean follow-up 42.1 months) were analyzed retrospectively for factors ECRT autograft-host bone union.

RESULTS

On univariate analysis, age < 20 years, metaphyseal osteotomy site, V-shaped diaphyseal osteotomy, and use of additional plate at diaphyseal osteotomy had a significantly faster time to union, while gender, tumour type, bone involved, resection length, chemotherapy, type of fixation, and use of intra-medullary fibula did not influence union time. In multivariate analysis, V-shaped diaphyseal osteotomy and use of additional plate at diaphyseal ostetomy were the independent factors with favourable time to union. None of the analyzed factors was found to have a significant effect on the union rate. The major complications were non-union in 11.4% patients, graft failure in 2.1%, infection in 12.5%, and soft tissue local recurrences in 14.5% patients.

CONCLUSION

Modified diaphyseal osteotomy and augmentation of the stability of the reconstruction using additional small plates enhance the incorporation of ECRT autograft.

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.

Factors Influencing Nonunion and Fracture Following Biological Intercalary Reconstruction for Lower-Extremity Bone Tumors: A Systematic Review and Pooled Analysis

OBJECTIVES

To determine nonunion rate, fracture rate, and their risk factors following biological intercalary reconstruction for lower extremity bone tumors.

METHODS

A systematic review and pooled analysis were conducted. PubMed, Embase, and Wiley Cochrane Library were searched from inception up to June 01, 2020. Studies concerning biological intercalary reconstruction after resection of lower extremity bone tumors were included. Overall nonunion and fracture rates were calculated. For studies reporting patient outcomes individually with precise graft characteristics and fixation methods, the individual data were extracted. Patients with demographical and clinical characteristics, including age, sex, tumor location, graft characteristics, and fixation method, were pooled for a multivariate analysis. For each factor of interest, odds ratio (OR), 95% confidence interval (95% CI), and p-value from logistic regression were reported.

RESULTS

A total of 2776 articles were identified from the initial literature search and 76 studies (2052 patients) were included. Sixty-nine studies were case series and seven were comparative studies. The overall nonunion rate was 19% (382/2052; range: 0%-53%), and the overall fracture rate was 17% (344/2052; range: 0%-75%). Thirty of the 76 studies (362 patients) reported patients' characteristics individually and were thus included in the pooled multivariate analysis. Intramedullary nail fixation was associated with a significantly higher nonunion rate compared to plate fixation (OR = 2.2, 95% CI: 1.23-4.10, p = 0.009). Reconstruction with a vascularized fibula graft had a statistically non-significant lower nonunion rate than reconstruction without the graft (OR = 0.6, 95% CI: 0.34-1.07, p = 0.086). Devitalized autografts had a lower fracture risk than allografts (OR = 0.3, 95% CI: 0.14-0.64, p = 0.002), and males tended to have higher fracture risk than females (OR = 2.1, 95% CI: 1.00-4.44, p = 0.049).

CONCLUSIONS

Reconstruction with intramedullary nail fixation is related to an elevated risk of nonunion. Allografts and males have a higher fracture risk than devitalized autografts and females, respectively. Further high-quality comparative analyses with large sample sizes and adequate follow-up duration are needed to validate these findings.

Reconstruction for bone tumours of the shoulder and humerus in children and adolescents

Reconstructions for paediatric bone tumours of the shoulder girdle and humerus are intended to optimize placement of the hand in space. Given the longevity of paediatric survivors of sarcoma, durability is an important planning consideration. Here, I review a subset of approaches based on anatomical site with an emphasis on function and longevity. Often, biological reconstructions that combine living bone with tendon repairs and transfers best address those goals.

Preliminary Results of the "Capasquelet" Technique for Managing Femoral Bone Defects-Combining a Masquelet Induced Membrane and Capanna Vascularized Fibula with an Allograft

We describe the preliminary results of a novel two-stage reconstruction technique for extended femoral bone defects using an allograft in accordance with the Capanna technique with an embedded vascularized fibula graft in an induced membrane according to the Masquelet technique. We performed what we refer to as "Capasquelet" surgery in femoral diaphyseal bone loss of at least 10 cm. Four patients were operated on using this technique: two tumors and two traumatic bone defects in a septic context with a minimum follow up of one year. Consolidation on both sides, when achieved, occurred at 5.5 months (4-7), with full weight-bearing at 11 weeks (8-12). The functional scores were satisfactory with an EQ5D of 63.3 (45-75). The time to bone union and early weight-bearing with this combined technique are promising compared to the literature. The osteoinductive role of the induced membrane could play a positive role in the evolution of the graft. Longer follow up and a larger cohort are needed to better assess the implications. Nonetheless, this two-stage technique appears to have ample promise, especially in a septic context or in adjuvant radiotherapy in an oncological context.

Is three-dimensional-printed custom-made ultra-short stem with a porous structure an acceptable reconstructive alternative in peri-knee metaphysis for the tumorous bone defect?

Background

Long-lasting reconstruction after extensive resection involving peri-knee metaphysis is a challenging problem in orthopedic oncology. Various reconstruction methods have been proposed, but they are characterized by a high complication rate. The purposes of this study were to (1) assess osseointegration at the bone implant interface and correlated incidence of aseptic loosening; (2) identify complications including infection, endoprosthesis fracture, periprosthetic fracture, leg length discrepancy, and wound healing problem in this case series; and (3) evaluate the short-term function of the patient who received this personalized reconstruction system.

Methods

Between September 2016 and June 2018, our center treated 15 patients with malignancies arising in the femur or tibia shaft using endoprosthesis with a 3D-printed custom-made stem. Osseointegration and aseptic loosening were assessed with digital tomosynthesis. Complications were recorded by reviewing the patients’ records. The function was evaluated with the 1993 version of the Musculoskeletal Tumor Society (MSTS-93) score at a median of 42 (range, 34 to 54) months after reconstruction.

Results

One patient who experienced early aseptic loosening was managed with immobilization and bisphosphonates infusion. All implants were well osseointegrated at the final follow-up examination. There are two periprosthetic fractures intraoperatively. The wire was applied to assist fixation, and the fracture healed at the latest follow-up. Two patients experienced significant leg length discrepancies. The median MSTS-93 score was 26 (range, 23 to 30).

Conclusions

A 3D-printed custom-made ultra-short stem with a porous structure provides acceptable early outcomes in patients who received peri-knee metaphyseal reconstruction. With detailed preoperative design and precise intraoperative techniques, the reasonable initial stability benefits osseointegration to osteoconductive porous titanium, and therefore ensures short- and possibly long-term durability. Personalized adaptive endoprosthesis, careful intraoperative operation, and strict follow-up management enable effective prevention and treatment of complications. The functional results in our series were acceptable thanks to reliable fixation in the bone-endoprosthesis interface and an individualized rehabilitation program. These positive results indicate this device series can be a feasible alternative for critical bone defect reconstruction. Nevertheless, longer follow-up is required to determine whether this technique is superior to other forms of fixation.

Is the Capanna Technique a Reliable Method for Revision Surgery after Failure of Previous Limb-Salvage Surgery?

BACKGROUND

Reconstruction of a massive bone defect caused by previous failed limb-salvage surgery in patients with bone sarcoma is challenging. Many procedures have been used, but they all have their inherent disadvantages. The Capanna technique has demonstrated good functional outcomes and a low incidence of complications in primary reconstructive surgery of massive bone defect. However, few studies have focused on its usage in revision surgery after failed primary limb-salvage surgery.

METHODS

Between June 2011 and January 2017, 13 patients underwent revision surgery with the Capanna technique for reconstruction of a secondary segmental bone defect caused by a previous failed surgical procedure. The demographics, operating procedures, graft union, functional outcomes, oncologic outcomes, and postoperative complications of each patient were recorded.

RESULTS

The current study investigated 13 patients. The rate of limb salvage was 100 %. Bone union was achieved for all patients during a mean time of 8.54 ± 2.15 months (range 4-11 months) at the fibula-host bone junction and 14.92 ± 2.33 months (range 12-21 months) at the allograft-host bone junction. The postoperative complications included wound healing issues and internal fixation loosening. Allograft fracture, nonunion, and infection were not observed. All the patients achieved good functional outcomes, with a Musculoskeletal Tumor Society (MSTS) score of 0.86 ± 0.03 at the latest follow-up visit.

CONCLUSIONS

The Capanna technique is a reliable alternative method for revision reconstruction of a segmental bone defect caused by a previous failed surgical procedure.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Composite-Free Vascularized Fibular Epiphyseal Flap and Proximal Humeral Allograft for Proximal Humerus Reconstruction in a Pediatric Patient

Tumors involving the epiphysis in children present a reconstructive challenge. A free vascularized fibula epiphyseal transfer offers a means for biological reconstruction and longitudinal growth; however, it is often complicated by graft fracture and limited shoulder motion. Here, we present a case of a composite structural allograft with free vascularized fibula epiphyseal transfer for proximal humeral reconstruction. At 27-month follow-up, there was longitudinal growth, hypertrophy of the epiphysis, shoulder function which allowed activities of daily living, and no graft fracture.

'Umbrella construct' - an innovative technique for reconstruction of the proximal humerus after curettage in locally aggressive benign bone tumours

AIM

Reconstructing locally aggressive benign bone tumours of the proximal humerus after intralesional curettage is a challenge. We present a novel reconstruction technique 'Umbrella construct' where a femoral head and a strut allograft are combined to reconstruct the cavity. Complications, graft incorporation time, functional (Musculoskeletal Tumor Society score [MSTS]) and oncological outcomes were evaluated.

METHODS

Between January 2006 and June 2017, 11 cases (10 giant cell tumours, 1 chondroblastoma) underwent curettage followed by reconstruction with Umbrella construct. There were six females and five males with a mean age of 23 years (range 14-36 years). The maximum longitudinal extent of disease was 9 cm (range 5-9 cm).

RESULTS

The median follow-up was 54 months (range 34-122 months). The mean allograft incorporation time was 7 months (5-8 months). One patient had a graft fracture which was managed conservatively. Two cases developed local recurrence and the construct was revised to a prosthesis in both. The mean MSTS score for the nine cases with retained graft was 27 (23-29).

CONCLUSIONS

Umbrella construct is an effective reconstruction modality which helps to maintain joint congruity and limb length. It has acceptable oncological outcomes with good function.

Intercalary Allograft Reconstruction of the Proximal Tibia With and Without a Free Fibula Flap in Pediatric Patients

BACKGROUND

Limb salvage of the proximal tibia can be difficult due to the growth potential of and functional demands of the pediatric patients. Multiple reconstruction techniques exist, however, the ideal form of reconstruction is yet to be elucidated. The purpose of the current study is to evaluate outcomes in patients with an intercalary resection of the proximal tibia reconstructed with an allograft with or without a free vascularized fibula flap (FVF).

METHODS

Seventeen pediatric patients (9 males, 8 females) underwent lower extremity limb salvage with the use of intercalary cadaveric allograft at a mean age of 12±4 years. The most common diagnoses were osteosarcoma (n=6) and Ewing sarcoma (n=6). Patients were reconstructed with an allograft alone (n=6) or supplemented with an FVF (n=11).

RESULTS

All surviving patients had at least 2 years of clinical follow-up, with the mean follow-up of 12±7 years. The mean time to union of the allograft was 11±4 months, with 6 patients requiring additional bone grafting. There was no difference in the need for an additional bone graft (odds ratio=1.14, P=1.0) between patients with an FVF and those without. Four patients underwent an amputation, all with an allograft alone, due to disease recurrence (n=2) and due to infection (n=2). As such, there was a higher 10-year overall limb-salvage rate when the allograft was combined with an FVF compared with an allograft alone (100% vs. 33%, P=0.001). At last follow-up, the mean Mankin and Musculoskeletal Tumor Society rating was 86%, with a higher mean score in patients reconstructed with an FVF (94% vs. 70%, P=0.002).

CONCLUSION

Use of an intercalary allograft supplemented with an FVF to reconstruct the proximal tibia provides a durable means of reconstruction with an excellent functional outcome following oncologic proximal tibia resection in a pediatric population.

LEVEL OF EVIDENCE

Level III-therapeutic level.

Implementation of the three-dimensional printing technology in treatment of bone tumours: a case series

PURPOSE

With the ability to overcome specific anatomical and pathological challenges, 3D printing technology is setting itself as an important tool in patient-specific orthopaedics, delivering anatomical models, patient-specific instruments, and custom-made implants. One of the most demanding procedures in limb salvage surgery is the reconstruction of bony defects after tumour resection. Even though still limited in clinical practice, early results of the use of 3D technology are gradually revealing its potentially huge impact in bone tumour surgery. Here, we present a case series illustrating our experience with the use of 3D printing technology in the reconstruction of bone defects after tumour resection, and its impact on cosmesis and quality of life.

METHODS

We performed a retrospective analysis of 11 patients in whom a custom-made 3D-printed prosthesis was used to reconstruct a bone defect after resection for a bone tumour. Ten out of 11 patients were children (aged between 5 and 16 years) with osteosarcoma or Ewing sarcoma of the pelvis (2 children) or the arm (8 children), and one patient was a 67-year-old lady with a chondrosarcoma of the pelvis. All underwent wide resections resulting in considerable bone defects necessitating further reconstruction.

RESULTS

Custom-made implants were extremely useful both in reconstruction of bone defects and in terms of cosmesis, recovery facilitation, and quality of life. In this respect, pelvic and humeral reconstructions with 3D-printed custom implants particularly showed a great potential. The mean follow-up was 33 months. Four patients died of disease (36%) and overall the major and minor complication rate was 54% (6 out of 11 patients). Three patients had implant dislocation (27% [3/11 cases]), one had leg-compartment syndrome, and one patient reported limited range of motion. Only two out of 11 patients developed local recurrence.

CONCLUSION

Use of 3D customized implant helped us achieve two major goals in orthopaedic oncology-clear surgical resection and functional recovery with a good quality of life. Large studies with long-term follow-up are needed to reveal the value and future of 3D printing in orthopaedic oncology.