Endoprosthetic Reconstruction Research Articles

Total Humeral Endoprosthetic Reconstruction: A Systematic Review.

Total humeral endoprosthetic reconstruction (THER) is a rare reconstruction option for limb salvage surgery for large humeral neoplasms or bone destruction. Because of the limited data and need for this procedure, we reviewed the literature surrounding THER and assessed functionality, complications, and revisions using the PubMed, Embase, Ovid, and Scopus databases. Among 29 articles and 175 patients, the most common indication was neoplasm (n=25, 86%), mean follow-up was 61.98 months (SD=55.25 months), and mean Musculoskeletal Tumor Society score was 73.64% (SD=10.69%). Reported complications included 26 (23%) revisions in 7 studies, 35 (36%) cases of shoulder instability in 7 studies, and 13 (13.54%) cases of deep infection in 4 studies. THER should be considered with a thorough knowledge of outcomes and potential complications to guide patient and clinician expectations. [Orthopedics. 202x;4x(x):xx-xx.].

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

Hip transposition surgery after surgical resection of large pelvic tumours is a well-established alternate to endoprosthetic reconstruction. The major goals of surgery are to ensure adequate resection margins with limb salvation, albeit with acceptable levels of morbidity. While surveillance is aimed at diagnosing local recurrence or distant metastasis primarily, other complications may occasionally be seen.The aim of this study was to assess incidence of avascular necrosis (AVN) in the preserved native femoral heads after hip transposition surgery for periacetabular malignancies, also known as hanging hip surgery. Patient records and follow-up imaging of 22 patients who had undergone hanging hip surgery from 1999 to 2020 were retrospectively analysed to assess for any probable causes of AVN. Of the 22 patients, 5 (22.7%) had developed AVN on follow-up with a mean time of onset of about 10.5 months from surgery (5 months-2 years). A review of the patient demographics, surgical notes, preoperative management did not offer any clues as to the cause of AVN in these patients. Osteopenia was the most common radiological finding (59%) in most patients, but this also did not herald AVN onset. The theory that loss of major vascular supply to the femoral head from capsular disruption during hip transposition surgery would lead to AVN in most patients did not hold true as AVN occurred in a small number of patients.

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

Surgical treatment of musculoskeletal tumors in the periacetabular region present extremely difficult due to the complex anatomy and need for reconstruction. Orthopedic surgeons face more difficulties in patients with neurological conditions, which can cause increased muscle tone, an elevated risk of fractures, and compromised bone quality. There is limited evidence regarding endoprosthetic reconstruction for periacetabular tumors in individuals with neurological disorders. We conducted a single-center retrospective study to examine the outcomes of patients with preexisting neurological conditions who underwent surgery to remove periacetabular tumors and who underwent endoprosthesis reconstruction. Clinical presentation, detailed neurological conditions, complications, and functional outcomes were studied. Sixteen out of the 838 patients were identified (1.91%), with a mean follow-up time of 33 months. The primary neurological conditions encompassed Parkinson's disease, Alzheimer's disease, dementia, and cerebral ischemic stroke. Every patient was diagnosed with periacetabular lesions that were either primary or oligometastatic. They underwent tumor resection and subsequently received endoprosthetic reconstruction of the hemipelvis. Three patients developed metastasis lesions later, and two patients experienced tumor recurrence. Five cases experienced hip dislocation-one with periprosthetic fracture and one with surgical site infection. The position of the prosthetic rotating center was not correlated with dislocation. The reoperation rate was 31.25%. The cohort of patients all presented with more extended hospital stays and rehabilitation. In 3 patients, the general functional score was good, while in 6 patients, it was fair; in 7 patients, it was regarded as poor. The average MSTS93 score was 49.71%. Endoprosthetic reconstruction after periacetabular tumor resection is an effective way to eliminate tumors and salvage limbs. However, this group of patients has an increased likelihood of secondary surgery, complications, extended hospital stay, and no significant improvement in functional outcomes. Despite the diverse nature of the cohort, it is recommended to consider enhanced soft tissue reconstruction, supervised functional recovery and rehabilitation training.

Early radiological outcomes of a fully porous bridging collar in lower-limb endoprosthetic reconstructions: a case-matched retrospective series to assess osseointegration

BackgroundLimb-salvage surgery involving the utilization of endoprosthetic replacements is commonly employed following segmental bone resection for primary and secondary bone tumors. This study aimed to evaluate whether a fully porous bridging collar promotes early osseous integration in endoprosthetic replacements.MethodsWe undertook a retrospective review of all lower-limb endoprostheses utilizing a fully porous endosteal bridging collar design. We matched this cohort with a conventional extra-osteal non-porous fully hydroxyapatite-coated grooved collar cohort according to surgical indication, implant type, resection length, age, and follow-up time. At 6, 12, and 24 months post-implantation, radiographs were assessed for the number of cortices with or without osseointegration on orthogonal radiographs. Each radiograph was scored on a scale of -4 to + 4 for the number of cortices bridging the ongrowth between the bone and the collar of the prosthesis. Implant survival was estimated using the Kaplan–Meier method, and the mean number of osseointegrated cortices at each time point between the collar designs was compared using a paired t-test.ResultsNinety patients were retrospectively identified and analyzed. After exclusion, 40 patients with porous bridging collars matched with 40 patients with conventional extra-osteal non-porous collars were included in the study (n = 80). The mean age was 63.4 years (range 16–91 years); there were 37 males and 43 females. The groups showed no difference in implant survival (P = 0.54). The mean number of cortices with radiographic ongrowth for the porous bridging collar and non-porous collar groups was 2.1 and 0.3, respectively, at 6-month (P < 0.0001), 2.4 and 0.5, respectively, at 12-month (P = 0.044), and 3.2 and -0.2, respectively, at 24-month (P = 0.18) radiological follow-up.ConclusionThese findings indicate that fully porous bridging collars increased the number of cortices, with evidence of bone ongrowth between 6 and 24 months post-implantation. By contrast, extra-osteal collars exhibited reduced evidence of ongrowth between 6 and 24 months post-implantation. In the medium term, the use of a fully porous bridging collar may translate to a reduced incidence of aseptic loosening.Graphical

Proximal Humerus Reconstruction for Bone Sarcomas: A Critical Analysis.

» The proximal humerus is a common location for primary bone tumors, and the goal of surgical care is to obtain a negative margin resection and subsequent reconstruction of the proximal humerus to allow for shoulder function.» The current evidence supports the use of reverse total shoulder arthroplasty over hemiarthroplasty when reconstructing the proximal humerus after resection of a bone sarcoma if the axillary nerve can be preserved.» There is a lack of high-quality data comparing allograft prosthetic composite (APC) with endoprosthetic reconstruction of the proximal humerus.» Reverse APC should be performed using an allograft with donor rotator cuff to allow for soft-tissue repair of the donor and host rotator cuff, leading to improvements in shoulder motion compared with an endoprosthesis.

Oncology

The February 2024 Oncology Roundup360 looks at: Does primary tumour resection improve survival for patients with sarcomas of the pelvis with metastasis at diagnosis?; Proximal femur replacements for an oncologic indication offer a durable endoprosthetic reconstruction option: a 40-year experience; The importance of awaiting biopsy results in solitary pathological proximal femoral fractures: do we need to biopsy solitary pathological fractures?; Effect of radiotherapy on local recurrence, distant metastasis, and overall survival in 1,200 extremity soft-tissue sarcoma patients; What to choose in bone tumour resections? Patient-specific instrumentation versus surgical navigation; Optimal timing of re-excision in synovial sarcoma patients: immediate intervention versus waiting for local recurrence; Survival differences of patients with resected extraskeletal osteosarcoma receiving two different (neo) adjuvant chemotherapy regimens; Solitary versus multiple bone metastases in the appendicular skeleton: should the surgical treatment be different?.

Larger stem to bone diameter ratio predicts lower cemented endoprosthesis failure.

With continued advances in treatment options, patients with endoprosthetic reconstruction are living longer and consequently relying upon their devices for a longer duration. Major causes of endoprosthesis failure include aseptic loosening and mechanical failure. In the setting of tumor resection, loss of bone stock and use of radiation therapy increase the risk for these complications. As such, considerations of remaining native bone and stem length and diameter may be increasingly important. We asked the following questions: (1) What was the overall rate of endoprosthesis failure at a minimum of 5-year follow-up? (2) Does resection length increase implant failure rates? (3) Does implant size and its ratio to cortical width of bone alter implant failure rates? We retrospectively analyzed patient outcomes at a single institution between the years of 1999-2022 who underwent cemented endoprosthetic reconstruction at the hip or knee and identified 150 patients. Of these 150, 55had a follow-up of greater than 5 years and were used for analysis. Radiographs of these patients at time of surgery were assessed and measured for resection length, bone diameter, stem diameter, and remaining bone length. Resection percentage, and stem to bone diameter ratios were then calculated and their relationship to endoprosthesis failure were analyzed. Patients in this cohort had a mean age of 55.8, and mean follow-up of 59.96 months. There were 78 distal femoral replacements (52%), 16 proximal femoral replacements (10.7%), and 56 proximal tibial replacements (37.3%). There were five patients who experienced aseptic loosening and six patients who experienced mechanical failure. Patients with implant failure had a smaller mean stem to bone diameter (36% vs. 44%; p = 0.002). A stem to bone diameter of 40% appeared to be a breaking point between success and failure in this series, with 90% of patients with implant failure having a stem: bone ratio less than 40%. Stem to bone ratio less than 40% increased risk for failure versus stems that were at least 40% the diameter of bone (6/19 [31.6%] vs. 0/36 [0%]; odds ratio 0.68; p < 0.001). Resection length did not appear to have an impact on the rates of aseptic loosening and mechanical failure in this series. Data from this series suggests a benefit to using stems with a larger diameter when implanting cemented endoprostheses at the hip or knee. Stems which were less than 40% the diameter of bone were substantially more likely to undergo implant failure.

Reducing the prosthesis modulus by inclusion of an open space lattice improves osteogenic response in a sheep model of extraarticular defect.

Introduction: Stress shielding is a common complication following endoprosthetic reconstruction surgery. The resulting periprosthetic osteopenia often manifests as catastrophic fractures and can significantly limit future treatment options. It has been long known that bone plates with lower elastic moduli are key to reducing the risk of stress shielding in orthopedics. Inclusion of open space lattices in metal endoprostheses is believed to reduce the prosthesis modulus potentially improving stress shielding. However, no in vivo data is currently available to support this assumption in long bone reconstruction. This manuscript aims to address this hypothesis using a sheep model of extraarticular bone defect. Methods: Initially, CT was used to create a virtual resection plan of the distal femoral metaphyses and to custom design endoprostheses specific to each femur. The endoprostheses comprised additively manufactured Ti6Al4V-ELI modules that either had a solid core with a modulus of ∼120GPa (solid implant group) or an open space lattice core with unit cells that had a modulus of 3-6GPa (lattice implant group). Osteotomies were performed using computer-assisted navigation followed by implantations. The periprosthetic, interfacial and interstitial regions of interest were evaluated by a combination of micro-CT, back-scattered scanning electron microscopy (BSEM), as well as epifluorescence and brightfield microscopy. Results: In the periprosthetic region, mean pixel intensity (a proxy for tissue mineral density in BSEM) in the caudal cortex was found to be higher in the lattice implant group. This was complemented by BSEM derived porosity being lower in the lattice implant group in both caudal and cranial cortices. In the interfacial and interstitial regions, most pronounced differences were observed in the axial interfacial perimeter where the solid implant group had greater bone coverage. In contrast, the lattice group had a greater coverage in the cranial interfacial region. Conclusion: Our findings suggest that reducing the prosthesis modulus by inclusion of an open-space lattice in its design has a positive effect on bone material and morphological parameters particularly within the periprosthetic regions. Improved mechanics appears to also have a measurable effect on the interfacial osteogenic response and osteointegration.

Older age at surgery and postoperative leg length discrepancy are risk factors for unfavourable patient-reported outcome measures of knee tumour endoprostheses following resection for musculoskeletal tumour of the lower limb.

To evaluate mid-to long-term patient-reported outcome measures (PROMs) of endoprosthetic reconstruction after resection of malignant tumours arising around the knee, and to investigate the risk factors for unfavourable PROMs. The medical records of 75 patients who underwent surgery between 2000 and 2020 were retrospectively reviewed, and 44 patients who were alive and available for follow-up (at a mean of 9.7 years postoperatively) were included in the study. Leg length discrepancy was measured on whole-leg radiographs, and functional assessment was performed with PROMs (Toronto Extremity Salvage Score (TESS) and Comprehensive Outcome Measure for Musculoskeletal Oncology Lower Extremity (COMMON-LE)) with two different aspects. The thresholds for unfavourable PROMs were determined using anchor questions regarding satisfaction, and the risk factors for unfavourable PROMs were investigated. The thresholds for favourable TESS and COMMON were 64.8 and 70.4 points, respectively. Multivariate analysis showed that age at surgery (p = 0.004) and postoperative leg length discrepancy (p = 0.043) were significant risk factors for unfavourable TESS results, while age at surgery (p < 0.001) was a significant risk factor for unfavourable COMMON-LE results. Following receiver operating characteristic analysis, the threshold for both TESS and COMMON-LE was 29 years of age at surgery. Additionally, a leg length discrepancy of 8.2 mm was the threshold for unfavourable TESS. Patients aged > 29 years at the time of surgery require appropriate preoperative counselling and adequate postoperative physical and socioemotional support. Reconstruction equivalent to the length of the resected bone can reduce the risk of functional disabilities in daily living.

Oncology

The October 2023 Oncology Roundup360 looks at: Are pathological fractures in patients with osteosarcoma associated with worse survival outcomes?; Spotting the difference: how secondary osteosarcoma manifests in retinoblastoma survivors versus conventional cases; Accuracy of MRI scans in predicting intra-articular joint involvement in high-grade sarcomas around the knee; Endoprosthetic reconstruction for lower extremity soft-tissue sarcomas with bone involvement; Local relapse of soft-tissue sarcoma of the extremities or trunk wall operated on with wide margins without radiation therapy; 3D-printed, custom-made prostheses in patients who had resection of tumours of the hand and foot; Long-term follow-up for low-grade chondrosarcoma; Evaluation of local recurrence and diagnostic discordance in chondrosarcoma patients undergoing preoperative biopsy; Radiological scoring and resection grade for intraosseous chondrosarcoma.

CORR Insights®: Proximal Femur Replacements for an Oncologic Indication Offer a Durable Endoprosthetic Reconstruction Option: A 40-year Experience.

CORR Insights®: Proximal Femur Replacements for an Oncologic Indication Offer a Durable Endoprosthetic Reconstruction Option: A 40-year Experience.

Intravenous tranexamic acid decreases intraoperative transfusion requirements and does not increase incidence of symptomatic venous thromboembolic events in musculoskeletal sarcoma surgery

Background and objectivesTranexamic acid (TXA) is poorly studied in patients with bone and musculoskeletal sarcoma due to perceived increased risk of venous thromboembolism (VTE). This study aims to assess the safety and efficacy of intravenous (IV) TXA for patients undergoing surgical resection of primary bone or soft-tissue sarcoma. MethodsA retrospective, single center review of adult patients with pelvic or extremity sarcoma who underwent surgical resections between January 2005 and March 2020 was performed. Patients between 2005 and 2012 were included as a historical comparison prior to the routine use of IV TXA for all sarcoma resections at our institution. ResultsThirty-nine non-TXA and 59 TXA resections were identified. Two non-TXA patients experienced symptomatic pulmonary embolism compared to zero VTEs amongst TXA patients. IV TXA administered at any dose significantly reduced the probability of intraoperative transfusion (p = 0.003) and the median units of blood transfused at the time of any perioperative transfusion (p = 0.007). Intraoperative times were significantly shorter for TXA patients (128 vs 190 min; p = 0.004). A subset of patients who underwent wide resection with endoprosthetic reconstruction and received TXA similarly showed decreased requirement for intraoperative transfusion (p = 0.014) and decreased procedure times (p = 0.009). ConclusionsDuring sarcoma resection, at least 1 g of IV TXA can safely decrease the need for any intraoperative transfusion and the median number of PRBCs transfused by 2 units when any perioperative transfusion is given.

The microbial profile of infected endoprosthetic reconstructions after wide excision for patients with musculoskeletal tumors: A call for pathogen-based practices.

Periprosthetic infection is a devastating complication following endoprosthetic reconstruction. This study utilized a large database of endoprostheses to describe the incidence, risk factors, and microbial profile of such infections to better catalogue and understand these catastrophic events. A retrospective review of endoprosthetic reconstructions for an oncologic indication from January 1, 1981 to December 31, 2020 was performed. Demographic, oncologic, procedural and outcome data was analyzed. Multivariable logistic regression was used to identify potential risk factors for infection with significance defined as p < 0.05. Forty four out of 712 (6.2%) reconstructions resulted in infection at a mean time of 39.9 ± 44.5 months. Revision surgery (odds ratio [OR] 6.14, p < 0.001) or having a postoperative wound complication (OR 7.67, p < 0.001) were significantly associated with infection. Staphylococcus aureus and Staphylococcus epidermidis were the most commonly cultured organisms at a rate of 34.1% (15/44) and 22.7% (10/44), respectively. Ten infections resulted in amputation; five due to antimicrobial-resistant infections and three due to polymicrobial infections. Understanding the microbial profile of patients undergoing endoprosthetic reconstruction is paramount. This study demonstrates a relatively high rate of polymicrobial and antibiotic-resistant infections that portend worse outcomes, thus suggesting that pathogen-specific infectious practices may be warranted. Retrospective cohort study, level III.

Reconstruction of a 3D-printed endoprosthesis after joint-preserving surgery with intraoperative physeal distraction for childhood malignancies of the distal femur

BackgroundJoint-salvage surgery has been proposed in children with metaphysis malignancy of the distal femur. However, there is still some drawbacks regarding to the surgical technique and endoprosthetic design. In this study, we evaluated the efficacy of a joint-sparing surgical technique for the distal femur in pediatric patients using intraoperative physeal distraction and reconstruction of a 3D-printed endoprosthesis.MethodsWe retrospectively analyzed pediatric patients with distal femoral malignancy who underwent intraoperative physeal distraction and 3D-printed endoprosthetic reconstruction. Clinically, we evaluated functional outcomes using the 1993 version of the Musculoskeletal Tumor Society (MSTS-93) score pre- and post-operation. Complications were also recorded.ResultsSeven children with a median age of 11 years (range 8–15 years) were finally included in our study. The median follow-up time was 30 months (range 27–59 months). The median postoperative functional MSTS-93 score was increased compared with the preoperative scores. The bone-implant interface showed good osseointegration. One patient developed deep infection and another had lung metastasis after surgery. Endoprosthetic complications were not observed.ConclusionWe recommended that joint-preserving surgery with intraoperative physeal distraction and a 3D-printed endoprosthesis for reconstruction as an option for malignancies of the distal femur in selected pediatric patients.

Risk Factors for All-Cause Early Reoperation Following Tumor Resection and Endoprosthetic Reconstruction: A Secondary Analysis from the PARITY Trial.

Oncologic resection and endoprosthetic reconstruction of lower-extremity musculoskeletal tumors are complex procedures fraught with multiple modes of failure. A robust assessment of factors contributing to early reoperation in this population has not been performed in a large prospective cohort. The aim of the present study was to assess risk factors for early reoperation in patients who underwent tumor excision and endoprosthetic reconstruction, with use of data from the Prophylactic Antibiotic Regimens in Tumor Surgery (PARITY) trial. Baseline characteristics were assessed, including age, sex, tumor type, tumor location, presence of a soft-tissue mass, diabetes, smoking status, chemotherapy use, and neutropenia. Operative factors were recorded, including operative time, topical antibiotics, silver-coated prosthetics, endoprosthetic fixation, extra-articular resection, length of bone resected, margins, tranexamic acid, postoperative antibiotics, negative-pressure wound therapy, and length of stay. Univariate analysis was utilized to explore the differences between patients who did and did not undergo reoperation within 1 year postoperatively, and a multivariate Cox proportional hazards regression model was utilized to explore the predictors of reoperation within 1 year. A total of 155 (25.7%) of 604 patients underwent ≥1 reoperation. In univariate analysis, tumor type (p < 0.001), presence of a soft-tissue mass (p = 0.045), operative time (p < 0.001), use of negative-pressure wound therapy (p = 0.010), and hospital length of stay (p < 0.001) were all significantly associated with reoperation. On multivariate assessment, tumor type (benign aggressive bone tumor versus primary bone malignancy; hazard ratio [HR], 0.15; 95% confidence interval [CI], 0.04 to 0.63; p = 0.01), operative time (HR per hour, 1.15; 95% CI, 1.10 to 1.23; p < 0.001), and use of negative-pressure wound therapy (HR, 1.93; 95% CI, 1.30 to 2.90; p = 0.002) remained significant predictors of reoperation within 1 year. Independent variables associated with reoperation within 1 year in patients who underwent tumor resection and endoprosthetic reconstruction included tumor type (benign aggressive bone tumor versus primary bone malignancy), operative time, and use of negative-pressure wound therapy. These results will help to inform patients and surgeons regarding the risk of reoperation by diagnosis and reinforce operative time as a factor influencing reoperation. These results also support further investigation into the use of negative-pressure wound therapy at the time of surgery in this patient population. Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Patient and Surgical Risk Factors for Surgical Site Infection in Lower-Extremity Oncological Endoprosthetic Reconstruction: A Secondary Analysis of the PARITY Trial Data.

The specific risk factors for surgical site infection (SSI) in orthopaedic oncology patients undergoing endoprosthetic reconstruction have not previously been evaluated in a large prospective cohort. In the current study, we aimed to define patient- and procedure-specific risk factors for SSI in patients who underwent surgical excision and endoprosthetic reconstruction for lower-extremity bone or soft-tissue tumors using the prospectively collected data of the Prophylactic Antibiotic Regimens in Tumor Surgery (PARITY) trial. PARITY was a multicenter, blinded, randomized controlled trial with a parallel 2-arm design that aimed to determine the effect of a long duration (5 days) versus short duration (24 hours) of postoperative prophylactic antibiotics on the rate of SSI in patients undergoing surgical excision and endoprosthetic reconstruction of the femur or tibia. In this secondary analysis of the PARITY data, a multivariate Cox proportional hazards regression model was constructed to explore predictors of SSI within 1 year postoperatively. A total of 96 (15.9%) of the 604 patients experienced an SSI. Of the 23 variables analyzed in the univariate analysis, 4 variables achieved significance: preoperative diagnosis, operative time, volume of muscle excised, and hospital length of stay (LOS). However, only hospital LOS was found to be independently predictive of SSI in the multivariate regression analysis (hazard ratio per day = 1.03; 95% confidence interval = 1.01 to 1.05; p < 0.001). An omnibus test of model coefficients demonstrated that the model showed significant improvement over the null model (χ2 = 78.04; p < 0.001). No multicollinearity was found. This secondary analysis of the PARITY study data found that the only independent risk factor for SSI on multivariate analysis was hospital LOS. It may therefore be reasonable for clinicians to consider streamlined discharge plans for orthopaedic oncology patients to potentially reduce the risk of SSI. Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

The Impact of Implant Fixation Type on Reoperation Rates Following Endoprosthetic Reconstruction Surgery.

Prospective evidence supporting the use of cemented or uncemented implants in endoprosthetic reconstruction is lacking. The present study aimed to determine the effect of cemented fixation compared with uncemented fixation on the rate of all-cause reoperation at 1 year postoperatively. This is a secondary analysis of the Prophylactic Antibiotic Regimens In Tumor Surgery (PARITY) trial. A total of 503 patients who underwent surgical excision and endoprosthetic reconstruction of a lower-extremity bone tumor were included in this analysis. A multivariate Cox proportional hazards model was utilized to assess the independent relationship between fixation group and implant survivorship, with all-cause reoperation as the end point. There were 388 cemented implants and 115 uncemented implants. Participants had a mean age of 42.7 years (standard deviation, 22.0 years), and 59% were male. Overall, 131 reoperations were identified over the 1-year follow-up period. There were no significant differences found in all-cause reoperation (hazard ratio [HR], 1.05; 95% confidence interval [CI], 0.70 to 1.57; p = 0.761), septic reoperation, or aseptic reoperation between cemented and uncemented fixation at 1 year postoperatively. The Cox regression analysis demonstrated that total operative time (HR per hour, 1.10; 95% CI, 1.02 to 1.20; p = 0.019) was an independent predictor of reoperation. The risk of reoperation was lower in patients with benign aggressive disease (HR, 0.11; 95% CI, 0.02 to 0.80; p = 0.029) or metastatic bone disease (HR, 0.30; 95% CI, 0.11 to 0.85; p = 0.023). Patients who underwent cemented fixation showed clinically meaningful functional improvement at 1 year postoperatively. Cemented compared with uncemented fixation has no effect on 1-year all-cause reoperation rates in endoprosthetic reconstruction surgery. Further research is required to investigate the long-term survival of cemented versus uncemented implants. Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Surgical Duration Is Independently Associated with an Increased Risk of Surgical Site Infection and May Not Be Mitigated by Prolonged Antibiotics: A Secondary Analysis of the PARITY Trial of Infection After Lower-Extremity Endoprosthetic Reconstruction for Bone Tumors.

Infection after tumor resection and endoprosthetic reconstruction is a potentially limb-threatening complication. The duration of surgery has been shown to be a risk factor for infection, but the ability of an extended duration of postoperative prophylactic antibiotics to potentially minimize that risk has not been specifically studied. The objective of this study was to determine whether extended postoperative antibiotic therapy protects against surgical site infection (SSI) in the setting of prolonged surgical duration in patients undergoing endoprosthetic reconstruction after tumor resection. This study was a planned secondary analysis of the Prophylactic Antibiotic Regimens in Tumor Surgery (PARITY) trial data set. Patients in the PARITY trial were randomized to receive 24 hours or 5 days of postoperative prophylactic antibiotics. The current study assessed the risk of SSI in those cohorts on the basis of surgical duration. A multivariable regression model was used to examine the adjusted effects of the duration of surgery on SSI, after controlling for other significant risk factors and potential confounders. All 604 patients who had been included in the final data analysis in the PARITY trial were also included in this secondary analysis. Those who sustained an SSI had a greater mean duration of surgery (6.2 hours) compared with those who did not sustain an SSI (4.9 hours, p < 0.0001). There was no specific time point at which the risk of infection significantly increased. Extended postoperative prophylactic antibiotic therapy did not appear to mitigate the risk of SSI even in patients with prolonged surgical duration. Increased surgical duration was an independent risk factor for SSI in orthopaedic patients undergoing endoprosthetic reconstruction after tumor resection. However, surgical duration is multifactorial and is influenced by several variables. For example, there may be protective features of flap coverage that increase surgical duration while paradoxically decreasing the risk of SSI. Extended postoperative antibiotic therapy did not mitigate the risk of infection in this cohort, and other risk mitigation strategies will need to be considered in future studies. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Pediatric and Adult Patients Have Similar Functional Improvement After Endoprosthetic Reconstruction of Lower-Extremity Tumors.

Although the treatment of lower-extremity bone tumors is similar between adult and pediatric patients, differences in outcomes are unknown. Outcomes for lower-extremity oncologic reconstruction have been challenging to study because of the low incidence and heterogeneity in disease and patient characteristics. The PARITY (Prophylactic Antibiotic Regimens in Tumor Surgery) trial is the largest prospective data set assembled to date for patients with lower-extremity bone tumors and presents an opportunity to investigate differences in outcomes between these groups. Patient details were acquired from the prospectively collected PARITY trial database. The 1993 Musculoskeletal Tumor Society (MSTS-93) and Toronto Extremity Salvage Score (TESS) questionnaires were administered preoperatively and at 3, 6, and 12 months postoperatively. Continuous outcomes were compared between groups with use of the Student t test, and dichotomous outcomes were compared with use of the Pearson chi-square test. A total of 150 pediatric and 447 adult patients were included. Pediatric patients were more likely than adult patients to have a primary bone tumor (146 of 150 compared with 287 of 447, respectively; p < 0.001) and to have received adjuvant chemotherapy (140 of 149 compared with 195 of 441, respectively; p < 0.001). Reoperation rates were not significantly different between age groups (45 of 105 pediatric patients compared with 106 of 341 adult patients; p ≤ 0.13). Pediatric patients had higher mean MSTS-93 scores (64.7 compared with 53.8 among adult patients; p < 0.001) and TESS (73.4 compared with 60.4 among adult patients; p < 0.001) at baseline, which continued to 1 year postoperatively (mean MSTS-93 score, 82.0 compared with 76.8 among adult patients; p = 0.02; mean TESS, 87.7 compared with 78.6 among adult patients; p < 0.001). Despite the differences in outcomes between cohorts, pediatric and adult patients demonstrated similar improvement in MSTS-93 scores (mean difference, 17.4 and 20.0, respectively; p = 0.48) and TESS (mean difference, 14.1 and 14.7, respectively; p = 0.83) from baseline to 1 year postoperatively. Pediatric patients had significantly better functional outcomes than adult patients at nearly all of the included postoperative time points; however, pediatric and adult patients showed similar mean improvement in these outcomes at 1 year postoperatively. These findings may be utilized to help guide the postoperative expectations of patients undergoing oncologic reconstruction. Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Proximal Femur Replacements for an Oncologic Indication Offer a Durable Endoprosthetic Reconstruction Option: A 40-year Experience.

Proximal femur replacements (PFRs) are an effective surgical option to treat primary and metastatic tumors causing large bony defects in the proximal femur. Given the relative rarity of these indications, current studies on PFR for oncologic indications are generally limited by patient volume or relatively short-term follow-up. Because recent advances in systemic therapy have improved the prognosis of patients who undergo limb salvage surgery for musculoskeletal tumors, data on the long-term durability of endoprosthetic reconstructions have become increasingly important. (1) How does the long-term survival of cemented bipolar PFRs compare with patient survival in patients who underwent PFR for benign, aggressive, and metastatic tumors? (2) What are common reasons for revisions of primary PFRs? (3) Which factors are associated with survival of primary PFRs? (4) What is the survivorship free from conversion of bipolar PFRs to THA? Between January 1, 1980, and December 31, 2020, we treated 812 patients with an endoprosthetic reconstruction for an oncologic indication. All patients who underwent a primary PFR for an oncologic indication were included in this study. The study cohort consisted of 122 patients receiving a primary PFR. Eighteen patients did not reach a censored endpoint such as death, revision, or amputation within 2 years. Thirty-three patients died within 2 years of their surgery. Of the 122 patients with primary PFRs, 39 did not reach a censored endpoint and have not been seen within the past 5 years. However, the mean follow-up time for these patients was longer than 10 years. The Social Security Death Index was queried to identify any patients who may have died but might not have been captured by our database To allow for adequate follow-up, endoprosthetic reconstructions performed after December 31, 2020 were excluded. The mean age at the time of the index surgery was 48 ± 22 years. The mean follow-up time of surviving patients was 7 ± 8 years. All PFRs were performed using a bipolar hemiarthroplasty with a cemented stem, and all implants were considered comparable. Demographic, oncologic, procedural, and outcome data including prosthesis survival, patient survival, complication rates, and rates of conversion to THA were analyzed. Patient, prosthesis, and limb salvage survival rates were generated, with implant revision as the endpoint and death as a competing risk. Statistical significance was defined as p < 0.05. Generally, patients with benign or low-grade (Stage I) disease outlived their implants (100% patient survival through 30 years; p = 0.02), whereas the opposite was true in patients with high-grade, localized Stage II disease (64% patient survival at 5 years [95% CI 49% to 76%]; p = 0.001) or widespread Stage III metastatic disease (6.2% patient survival at 5 years [95% CI 0.5% to 24%]; p < 0.001). Primary PFR implant survival at 5, 10, 20, and 30 years was 97% (95% CI 90% to 99%), 81% (95% CI 67% to 90%), 69% (95% CI 46% to 84%), and 51% (95% CI 24% to 73%), respectively. Eight percent (10 of 122) of primary PFRs were revised for any reason. The most common causes of revision were aseptic loosening (3% [four of 122]), infection (3% [three of 122]), breakage of the implant (2% [two of 122]), and tumor progression (1% [one of 122]). Follow-up time was the only factor that was associated with revision of primary PFRs. Neither segment length nor stem length were associated with revision of primary. Six percent (seven of 122) of PFRs were converted to THA at a mean 15 ± 8 years from the index procedure. Survivorship free from conversion to THA (accounting for death as a competing risk) was 94% (95% CI 85% to 99%), 86% (95% CI 68% to 94%). and 77% (95% CI 51% to 91%) at 10, 20, and 30 years, respectively. Cemented bipolar PFRs for an oncologic indication are a relatively durable reconstruction technique. Given the relative longevity and efficacy of PFRs demonstrated in our study, especially in patients with high-grade or metastatic disease where implant survival until all-cause revision was longer than patient survival, surgeons should continue to seriously consider PFRs in appropriate patients. The relative rarity of these reconstructions limits the number of patients in this study as well as in current research; thus, further multi-institutional collaborations are needed to provide the most accurate prognostic data for our patients. Level III, therapeutic study.