What Are the Complications, Reconstruction Survival, and Functional Outcomes of Modular Prosthesis and Allograft-prosthesis Composite for Proximal Femur Reconstruction in Children With Primary Bone Tumors?

Proximal femur reconstruction after bone tumor resection in children is a demanding surgery for orthopaedic oncologists because of the small bone size and possible limb-length discrepancy at the end of skeletal growth owing to physis loss. The most commonly used reconstruction types used for the proximal femur are modular prostheses and allograft-prosthesis composites. To our knowledge, there are no previous studies comparing the outcomes after modular prosthesis and allograft-prosthesis composite reconstruction of the proximal femur in children with primary bone tumors. (1) What was the cumulative incidence of reoperation for any reason after allograft-prosthesis composite and modular prosthesis reconstructions of the proximal femur in children with primary bone tumors? (2) What was the cumulative incidence of reconstruction removal or revision arthroplasty in those two treatment groups? (3) What complications occurred in those two treatment groups that were managed without further surgery or with surgery without reconstruction removal? Between 2000 and 2021, 54 children with primary bone tumors underwent resection and reconstruction of the proximal femur at a single institution. During that time, allograft-prosthesis composite reconstruction was used in very young children, in whom we prioritize bone stock preservation for future surgeries, and children with good response to chemotherapy, while modular prosthesis reconstruction was used in older children and children with metastatic disease at presentation and poor response to chemotherapy. We excluded three children in whom limb salvage was not possible and 11 children who underwent either reconstruction with free vascularized fibular graft and massive bone allograft (n = 3), an expandable prosthesis (n = 3), a massive bone allograft reconstruction (n = 2), a rotationplasty (n = 1), standard (nonmodular) prosthesis (n = 1), or revision of preexisting reconstruction (n = 1). Further, we excluded two children who were not treated surgically, three children with no medical or imaging records, and three children with no follow-up. All the remaining 32 children with reconstruction of the proximal femur (12 children treated with modular prosthesis and 20 children treated with allograft-prosthesis composite reconstruction) were accounted for at a minimum follow-up time of 2 years. Children in the allograft-prosthesis group were younger at the time of diagnosis than those in the modular prosthesis group (median 8 years [range 1 to 16 years] versus 15 years [range 9 to 17 years]; p = 0.001]), and the follow-up in the allograft-prosthesis composite group was longer (median 5 years [range 1 to 23 years] versus 3 years [range 1 to 15 years]; p = 0.37). Reconstruction with hemiarthroplasty was performed in 19 of 20 children in the allograft-prosthesis composite group and in 9 of 12 children in the modular prosthesis group. A bipolar head was used in 16 of 19 children, and a femoral ceramic head without acetabular cup was used in 3 of 19 children in the allograft-prosthesis composite reconstruction group. All 9 children in the modular prosthesis group were reconstructed with a bipolar hemiarthroplasty. Reconstruction with total arthroplasty was performed in one child in the allograft-prosthesis composite group and in three children in the modular prosthesis group. For both groups, we calculated the cumulative incidence of reoperation for any reason and the cumulative incidence of reconstruction removal or revision arthroplasty; we also reported qualitative descriptions of serious complications treated nonoperatively in both groups. The cumulative incidence of any reoperation at 10 years did not differ between the groups with the numbers available (36% [95% confidence interval 15% to 58%] in the allograft-prosthesis composite group versus 28% [95% CI 5% to 58%] in the modular proximal femoral replacement group). The cumulative incidence of reconstruction removal or revision arthroplasty at 10 years likewise did not differ between the groups with the numbers available (10% [95% CI 2% to 28%] versus 12% [95% CI 0% to 45%], respectively). In the allograft-prosthesis composite group (20 children), hip instability (n = 3), nonunion (n = 2), fracture of the greater trochanter (n = 1), screw loosening (n = 1), limb-length discrepancy (n = 1), and coxalgia due to acetabular wear (n = 1) were treated surgically without reconstruction removal. Complications treated without surgery included resorption of the allograft at the trochanteric region (n = 4), fracture of the greater trochanter (n = 4), limb-length discrepancy (n = 6), and coxalgia due to acetabular wear (n = 2). In the modular prosthesis group (12 children), hip instability (n = 1), coxalgia due to acetabular wear (n = 1), and limb-length discrepancy (n = 1) were treated surgically without reconstruction removal. Complications treated without surgery included hip instability (n = 2), stress shielding (n = 6), infection (n = 1), sciatic nerve palsy (n = 1), and limb-length discrepancy (n = 3). Although the two groups of children were not directly comparable due to differences in age and clinical characteristics, both modular prosthesis and allograft-prosthesis composite reconstructions of the proximal femur after bone tumor resection appear to be reasonable options with similar revision-free survival and complications. Therefore, the type of reconstruction following proximal resection in children with bone sarcoma should be chosen taking into consideration factors such as patient age, bone size, implant availability, technical expertise, and the surgeon's preference. Although children treated with expandable prostheses were not included in this study, such prostheses may be useful in bridging the surgical defect while correcting residual limb-length discrepancies even though they face limitations such as small intramedullary diameter, short residual bone segments, as well as stress shielding, loosening, and breakage. Level III, therapeutic study.

Atherley O'Meally A ，Rizzi G ，Cosentino M ，Aiba H ，Aso A ，Solou K ，Campanacci L ，Zuccheri F ，Bordini B ，Donati DM ，Errani C ... -  《-》

Is Proximal Femur Reconstruction With a Vascularized Fibula and Allograft Successful at Reconstructing a Tumor Resection in Children 6 Years of Age or Younger?

Treating bone sarcomas in young children, particularly in the proximal femur, is challenging because of the need to preserve growth potential, maintain joint function, and conserve bone for future revisions. In 1997, we introduced a new technique combining a vascularized fibula that preserved the proximal epiphysis to substitute for the femoral head and physis with a massive bone allograft aimed at providing a supportive scaffold for the autograft during growth. This approach initially showed promising results in both anatomic and functional restoration, but because it was a complex operation, we believed that longer term follow-up of this procedure would be helpful to judge its value as a potential reconstructive option. (1) What proportion of patients achieved allograft union; what proportion exhibited radiologic signs of vitality in the vascularized fibula, demonstrating bone growth and remodeling; what proportion avoided revision surgery; and what complications were observed with this technique? (2) What were the observed outcome scores using the Musculoskeletal Tumor Society (MSTS) score? (3) What was the status of the hip after treatment? Between 1997 and 2010, a total of 14 patients who were 6 years old or younger underwent resection of the proximal femur for a bone sarcoma in two sarcoma centers. Six patients were treated with a vascularized fibular autograft plus bulk allograft reconstruction. The median (range) length of the proximal femur resection was 13 (11 to 14) cm. During the period in question, we generally performed the vascularized fibular autograft plus bulk allograft when the acetabular diameter was < 36 mm. None of those who had the fibula autograft plus bulk allograft reconstruction were lost to follow-up before 2 years without meeting a study endpoint (revision, reoperation) or died prior to 2 years with implants intact. All six patients in the original group had either a follow-up of at least 14 years or had met a study endpoint (revision, reoperation) before that minimum surveillance duration; these patients were the focus of the current study. We noted that two patients had follow-up periods of 20 and 27 years but have not been seen in the last 5 years; they were included for survivorship analysis purposes, yet we emphasize that we cannot ascertain their current status. The median (range) follow-up was 17 (14 to 27) years. Six of six patients achieved allograft union, while five of six underwent reoperations, and four of six had the graft removed as part of a revision procedure at a median (range) of 19 (7 to 40) months. Only one patient maintained the original reconstruction after 27 years, despite an epiphysiolysis that occurred 56 months after surgery, which was corrected surgically. The other five patients experienced a complication of the reconstruction at a median (range) onset at 19 (7 to 40) months after surgery. Two of the six patients had a common peroneal nerve palsy at the harvested site. Allograft union was observed a median of 8 months from the index procedure. All patients presented residual limb length discrepancy ranging from 1 to 7 cm. The median (range) MSTS score before any revision was 38% (33% to 93%). Four of the six patients underwent removal of the biological reconstruction and were reconstructed by other methods. They displayed a median (range) MSTS functional score of 88% (73% to 93%) at most recent follow-up. One of the six patients showed progressive diaphyseal hypertrophy, growth, and remodeling of the epiphysis, along with integration with the allograft, and had a final limb length discrepancy of -1 cm. The vascularized fibular epiphysis was enlarged and remodeled to provide a new femoral head and grew similar to the physis of the native femoral head in this one patient. Biological reconstruction using a vascularized fibula and bone allograft in young patients with proximal femur sarcoma was not a durable solution for most patients, and it resulted in frequent unplanned reoperations and revisions. Only one of six patients in this small series had a reconstruction that lasted into adulthood. Even though this was a small group of patients, the poor survival of the construct, the frequent complications, and the unpredictable results associated with it led us to discontinue its use in favor of prosthetic replacement. Level IV, therapeutic study.

Cevolani L ，Staals EL ，Fernández-Fernández T ，Mammone A ，Innocenti M ，Campanacci DA ，Donati DM ，Manfrini M ，Campanacci L ... -  《-》

What Are the Functional, Radiographic, and Survivorship Outcomes of a Modified Cup-cage Technique for Pelvic Discontinuity?

Pelvic discontinuity (PD) presents a complex challenge in revision hip arthroplasty. The traditional cup-cage construct, which involves a screw-secured porous metal cup and an overlying antiprotrusio cage, has shown promising mid- to long-term results. However, there is limited information on the outcomes of modifications to the original technique. Our study aims to evaluate a modified technique in which the cup position is determined by the placement of the overlying cage, allowing for adjustments to achieve optimal orientation. Among patients treated for PD with a cup-cage construct in which the cup position was dictated by the position of the cage: (1) What are Harris hip scores achieved at a minimum of 2 years of follow-up? (2) What is the Kaplan-Meier survivorship free from aseptic loosening or component migration? (3) What is the Kaplan-Meier survivorship free from revision for any reason? (4) What surgical complications are associated with the procedure? Between October 2013 and January 2022, we performed 805 acetabular revisions. Among these, 33 patients with PD confirmed intraoperatively were considered potentially eligible for a cup-cage construct; no other method of surgical management was used. We performed 64% (21 of 33) of these procedures from October 2013 to January 2018, with 6% (2 of 33) of patients lost to follow-up before the minimum study follow-up of 2 years; these 19 patients were monitored over a period ranging from 70 to 115 months. A further 12 patients underwent this procedure from January 2018 to January 2022, with one lost to follow-up before the minimum study follow-up of 2 years; the other patients met the minimum 2-year follow-up requirement. The remaining 30 patients with data analyzed here (10 men, 20 women) had a mean ± SD age of 61 ± 12 years and a median BMI of 29 kg/m 2 (range 20 to 33 kg/m 2 ) at the time of revision surgery. Twenty-one patients underwent revision due to aseptic loosening, and nine due to periprosthetic joint infection (PJI). The causes of PD in our patients were as follows: cup aseptic loosening without significant osteolysis in 20% (6 of 30), where the loose cup caused erosion of the host bone, leading to PD; PJI in 30% (9 of 30); intraoperative iatrogenic PD in 3% (1 of 30); and osteolysis in 47% (14 of 30), which also resulted in aseptic loosening. The median follow-up time was 79 months (range 25 to 115 months). The Harris hip score was used to evaluate clinical outcomes, with preoperative values compared with the most recent follow-up. Radiographs were reviewed by two experienced surgeons at each follow-up visit to assess component loosening (defined as migration > 5 mm or the presence of circumferential radiolucent lines) or clear migration. PD was considered healed if bridging callus or trabecular bone was visible across the site of the discontinuity. Complications were assessed through a comprehensive review of electronic medical records. Kaplan-Meier analysis was used to estimate implant survivorship and radiographic loosening, with aseptic loosening or component migration as the endpoint, as well as survivorship free from any reoperation. The Harris hip score improved from a median of 39 (range 30 to 66) preoperatively to a median of 76 (range 30 to 90) postoperatively (median difference 33 [range 2 to 48]; p < 0.01). Within the limitations of two-dimensional (2D) radiographic imaging, successful bone graft integration and the healing of PD were noted in 83% (25 of 30) of patients. Kaplan-Meier survivorship free from radiographic signs of aseptic loosening or component migration was 100% (95% CI 100% to 100%) at 115 months. When any revision related to the acetabular component was considered the endpoint, survivorship free from acetabular component revision at 115 months after revision surgery was 100% (95% CI 100% to 100%). When the need for any reoperation was considered the endpoint, survivorship free from needing reoperation at 115 months after revision surgery was 85% for all patients (95% CI 73% to 100%). When including only patients with a follow-up time of > 4 years (20 of 30), survivorship free from needing reoperation at 115 months after revision surgery was 90% (95% CI 78% to 100%). Postoperative complications during the follow-up period included one early dislocation on the fifth day after surgery, treated with closed reduction and 6 weeks of abduction bracing. One femoral stem loosening occurred at 56 months postoperatively, although the acetabular component remained securely fixed; this patient declined revision surgery. One patient experienced a dislocation 5 months after surgery but refused treatment and opted for prolonged bed rest. Additionally, one patient underwent a debridement, antibiotics, and implant retention procedure 1 week after the revision surgery and subsequently showed no signs of infection at the latest follow-up, 38 months postoperatively. Our study highlights the effectiveness of a modified cup-cage technique in complex hip revisions, showing promising results in terms of construct survivorship and low complication rates. Surgeons could consider delaying screw fixation until after positioning the cage within the porous cup to allow for optimal adjustment and using metal augments for severe bone defects to achieve better alignment. Surgeon experience with the cup-cage technique is crucial for achieving optimal outcomes. Future studies should focus on long-term follow-up visits to assess the durability and effectiveness of these modifications and explore the comparative effectiveness versus other methods, such as custom triflange components and jumbo cups with distraction. Level III, therapeutic study.

Mu W ，Xu B ，Wahafu T ，Wang F ，Guo W ，Zou C ，Cao L ... -  《-》

Is Rotationplasty Still a Reasonable Reconstruction Option for Patients With a Femoral Bone Sarcoma? A Comparative Study of Patients With a Minimum of 20 Years of Follow-up After Rotationplasty and Lower Extremity Amputation.

Rotationplasty was first introduced as an alternative to above-the-knee amputation after resection of bone sarcomas of the distal femur by Salzer in 1974. Although the procedure involves a substantial body image issue, it has many advantages such as durability of the reconstruction (compared with limb salvage procedures) and avoidance of phantom pain (compared with amputation). Although several reports have shown intermediate outcomes of rotationplasty, very long-term results in terms of function, activity levels, and quality of life (QoL) in comparison with above-the-knee amputation have not been reported. This work aims to fill this gap left by prior reports. (1) Is there a difference in revision-free survival in very long-term follow-up after rotationplasty and transfemoral amputation or knee disarticulation? (2) Are patient activity levels after rotationplasty comparable with those after transfemoral amputation or knee disarticulation in the very long term? (3) Do activity levels differ in terms of QoL? (4) Within the group of patients who have undergone rotationplasty, is the ROM in the neo-knee associated with QoL 20 to 40 years later? Between 1961 and 1995, a total of 360 patients were treated for bone and soft tissue sarcoma of the lower extremity. Fifty-four patients were treated with A1 rotationplasty, 124 were treated with an amputation, and 182 were treated with a limb salvage procedure. Of those who underwent amputation or rotationplasty, 9% (11 of 124) and 15% (8 of 54), respectively, were lost to follow-up before a period of 20 years without meeting a study endpoint, and another 71% (88 of 124) and 44% (24 of 54), respectively, died prior to 20 years with intact residual limbs, leaving 20% (25 of 124) and 41% (22 of 54), respectively, of the original group who had a follow-up time of at least 20 years. Four patients with amputations declined to participate in the study, while three patients with transtibial amputations and one patient with a complete language barrier after rotationplasty were excluded. These 39 patients with a minimum follow-up time of 20 years (mean [range] 36 years [23 to 55]) were available and gave their consent to this retrospective comparative study at the local orthopaedic department. The decision between rotationplasty and endoprosthetic replacement was made after thorough consultation and according to the patient's choice. As general guidance, Salzer's idea was to provide rotationplasty to patients who had a strong desire for higher levels of activity. Endoprosthetic reconstructions were more likely indicated given a patient's preference for a cosmetically uncompromised limb. Amputation was primarily performed one decade before the availability of rotationplasty and was mostly an alternative to rotationplasty because of patient refusal or surgical limitations. Therefore, the two groups differed in age at follow-up; however, they did not differ in age at surgery, BMI, gender ratio, tumor entities, or tumor localization. All-cause revisions presented in Kaplan-Meier curves, pain sensation, and functional and QoL outcomes, such as ROM, University of California Los Angeles (UCLA) activity scores, 5-level EuroQol 5-domain (EQ-5D-5L) scores, and 36-Item Short Form survey scores, were assessed. There was no difference between patients after rotationplasty and amputation in terms of survivorship free from revision of unpredictable events at 20 years (86% [95% confidence interval (CI) 85% to 95%] versus 67% [95% CI 64% to 94%]; p = 0.27). There was no difference in median UCLA activity scores between the groups (rotationplasty 6 versus amputation 5; p = 0.18). Patients treated with a rotationplasty had less pain than those treated with amputation (EQ-5D-5L pain/discomfort, p < 0.01). The EuroQol (EQ) index was higher in patients who had rotationplasty in comparison with patients who underwent amputation (0.92 versus 0.81; p = 0.01). A linear regression model that controlled for length of follow-up, gender, age, and type of surgery found that having rotationplasty was associated with a better EQ index than undergoing amputation (R = 0.538, R2 corrected = 0.212; p = 0.011). There were positive correlations between the EQ index and both flexion (ρ = 0.53 [95% CI 0.03 to 0.82]; p = 0.03) and ROM (ρ = 0.54 [95% CI 0.05 to 0.82]; p = 0.03) in the neo-knee. After rotationplasty and amputation, patients show similarities at long-term follow-up in the use of external prostheses and in cosmetic issues after limb loss. Both groups might have benefitted from the advancements in prosthetics that have occurred and will continue to do so; however, in this study, patients seem to have better QoL after rotationplasty compared with those with amputation. This study intentionally did not compare outcomes after an extendible or modular endoprosthesis with outcomes after rotationplasty. However, failures after endoprosthetic reconstructions occur frequently in the long term, whereas they rarely exist after rotationplasty. The use of rotationplasty, therefore, might be a benefit not only to individual patients but also to stakeholders in healthcare systems. Furthermore, this study emphasizes the benefit of rotationplasty as a durable surgical method that enables patients for high physical performance. Therefore, tumor centers around the world should be aware of these benefits, and patients must be given the opportunity to receive information about it. Currently, rotationplasty might be beneficial in certain situations, at least when patients and/or parents accept this kind of reconstruction. Children younger than 5 to 7 years and small in height, patients considered for megaprostheses with borderline or insufficient soft tissue coverage, and even patients who are highly active and feel that sporting activities are most important for their lifestyle are potential candidates for rotationplasty. Furthermore, rotationplasty might be an option after failed limb salvage surgery. Level III, therapeutic study.

Hobusch GM ，Hofer C ，Döring K ，Ellersdorfer F ，Kelaridis T ，Windhager R ... -  《-》

What Factors Are Associated With Implant Revision in the Treatment of Pathologic Subtrochanteric Femur Fractures?

Limiting reoperation or revision after operative stabilization or endoprosthetic reconstruction of a pathologic subtrochanteric femur fracture reduces morbidity, but how best to achieve this remains controversial. Endoprosthetic reconstruction offers durable mechanical stability but may not be most appropriate in patients who are frail or who are not expected to survive more than a few months. For that reason, cumulative incidence survival (looking at the endpoint of reoperation or revision with death as a competing risk) and factors associated with revision after surgical stabilization or reconstruction-both of which remain poorly characterized to date-would help surgeons make better decisions on behalf of these patients. We analyzed patients who were operatively treated for pathologic subtrochanteric femur fracture, and we asked: (1) What is the cumulative incidence of reoperation and revision at 3 months, 1 year, and 2 years after surgery for pathologic subtrochanteric femur fracture in patients undergoing each treatment type with death as a competing risk? (2) What are the factors associated with implant revision after operative treatment of pathologic subtrochanteric femur fracture? (3) What is the overall survival of patients in this population after surgery? (4) How do clinical and surgical factors along with the frequency of complications compare in this population by operative treatment? Between January 2000 and December 2020, 422 patients underwent surgery for completed proximal femur pathologic fractures. After excluding patients with non-subtrochanteric femur fractures (71% [301]), fractures caused by primary tumors of bone (< 1% [2]), and insufficient data (1% [6]), we included 113 patients who underwent operative treatment of completed pathologic subtrochanteric femur fractures. Our study period spanned 20 years because although implant trends may have shifted, the overall operative objective for pathologic subtrochanteric femur fractures-restoring function and alleviating pain, regardless of the extent of bony union-have remained relatively unchanged during this period. Median follow-up time was 6 months (range 1 month to 20.6 years). Intramedullary nailing (IMN) was performed in 68% (77) of patients, proximal femur replacement (PFR) was performed in 19% (22), and open reduction and internal fixation (ORIF) was performed in 12% (14) of patients. IMN was performed in patients with a poor prognosis but in whom fracture stabilization was felt to be advantageous. In instances of complex fractures in which adequate reduction could not be achieved, ORIF was generally performed. PFR was generally performed in patients with a better prognosis in which long-term implant survival and patient function were prioritized. We found a higher proportion of women in the IMN group (73% versus 32% in PFR and 50% in ORIF; p = 0.001). Rapid growth tumors (Katagiri classification) were found in 25% of patients with IMN, 27% with PFR, and 43% with ORIF. The primary outcome was the cumulative incidence of reoperation or revision surgery after initial stabilization. Competing risk analysis with death as a competing event was performed to estimate the cumulative incidence for reoperation and revision. Factors associated with revision surgery were identified using the Cox proportional hazards model, which rendered HRs. All analyses were adjusted to control for potential confounders. The cumulative incidence for reoperation at 2 years was 5% (95% confidence interval [CI] 4% to 6%) for IMN, 15% (95% CI 9% to 22%) for PFR, and 32% (95% CI 15% to 50%) for ORIF (p = 0.03). The cumulative incidence for revision at 2 years was 4% (95% CI 3% to 4%) for IMN, 4% (95% CI 2% to 6%) for PFR, and 33% (95% CI 15% to 51%) for ORIF (p = 0.01). Factors associated with revision surgery were radioresistant tumor histology (HR 8.5 [95% CI 1.2 to 58.9]; p = 0.03) and ORIF (HR 6.3 [95% CI 1.5 to 27.0]; p = 0.01). The 3-month, 1-year, and 2-year overall survival was 80% (95% CI 71% to 87%), 35% (95% CI 26% to 45%), and 28% (95% CI 19% to 36%), respectively. Thirty-day postoperative complications did not differ by fixation type, but 90-day readmission was highest after ORIF (3 of 14 versus 4 of 22 in PFR and 4% [3 of 77] in IMN; p = 0.03) Periprosthetic joint infection (PJI) was more common after salvage PFR (2 of 6) than primary PFR (1 of 22) (p = 0.04). Primary PFR may be preferred for pathologic subtrochanteric femur fractures arising from radioresistant tumor types, as the cumulative incidence of revision was no different than for IMN while restoring function, alleviating pain, and offering local tumor control, and it less commonly develops PJI than salvage PFR. In complex fractures not amenable to IMN, surgeons should consider performing a PFR over ORIF because of the lower risk of revision and the added benefit of replacing the pathologic fracture altogether and offering immediate mechanical stability with a cemented endoprosthesis. Future studies might evaluate the extent of bone loss from local tumor burden, and this could be quantified and analyzed in future studies as a covariate as it may clarify when PFR is advantageous in this population. Level III, therapeutic study.

Leland CR ，Gonzalez MR ，Werenski JO ，Vallone AT ，Brighton KG ，Newman ET ，Lozano-Calderón SA ，Raskin KA ... -  《-》