What to improve: Results of fixed-hinge knee endoprosthesis reconstructions over 40 years in a single tumor center.

INTRODUCTION: Over the past decades, numerous structural changes in implants, medical treatments, and surgical techniques have been made for Malignant Bone Tumors (MBT) around the knee. However, the overall care improvement is still unclear. The method is crucial when analyzing outcomes in surveys involving tumors, and a thorough assessment of the mortality is mandatory because death acts as competing event. The aims of this study were: 1) a comprehensive and longitudinal assessment of the revisions with an extensive follow-up and adequate methods; 2) a complete mortality review to consider competing risks. HYPOTHESIS: The hypothesis was that some prosthesis's structural improvements were made while the surgical toll increased as well as an improvement of mortality was also expected. MATERIAL AND METHODS: Analyses were performed on 248 patients with MBT (mean follow-up was 8.7 years, surgeries between 1972 and 2017). Three prosthesis models were successively used over time: 120 Guepar (older model), 42 Tornier, and 86 Stanmore (more recent model). The primary outcome was the assessment of revisions sorted out according to Henderson: type-1 soft-tissue failures or instability, type-2 aseptic loosening, type-3 structural failures, type-4 periprosthetic infections, type-5 tumoral progression. Death and amputations were considered as competing events. An extensive assessment of mortality was performed by merging the dataset with the French register of Deaths (INSEE). Cumulative probabilities were computed at 2, 5, 10, and 15 years and compared with Gray's tests. RESULTS: The overall 5-year survival was, 80% (95% CI: 73-87) for Guepar, 69% (95% CI: 56-84) for Tornier, and 71% (95% CI: 62-82) for Stanmore (p=0.4). The 5-year cumulative risks for type-1 were 5% (95% CI: 1-9), 9% (95% CI: 0-18), and 17% (95% CI: 9-25) for Guepar, Tornier, and Stanmore, respectively (p=0.01). The 15-year cumulative risks for type-2 were 22% (95% CI: 15-39), 8% (95% CI: 0-17) and 8% (95% CI: 2-14) for Guepar, Tornier, and Stanmore, respectively (p=0.10). Ten patients had an implant failure, nine Guepar, and one Tornier. The 5-year cumulative risks for type-4 were 7% (95% CI: 2-12), 19% (95% CI: 7-31), and 12% (95% CI: 5-18) for Guepar, Tornier, and Stanmore, respectively (p=0.08). There were 29 tumoral progressions; the 15-year risks were 16% (95% CI: 2-22), 2% (95% CI: 0-7%), and 12% (95% CI: 4-19%) for Guepar, Tornier, and Stanmore, respectively (p=0.08). No difference whatsoever was found between the proximal tibial and distal femur. CONCLUSION: There were some improvements in prosthesis design (forged steel instead of cast steel) and probably also in cemented stem fixation, but not in prosthetic joint infection and local recurrence over forty years. The overall mortality did not change significantly over the last 40 years amongst this specific cohort of patients who benefited from a hinge reconstruction prosthesis. LEVEL OF EVIDENCE: III; comparative case series with sensibility analysis.

Bone allografting: an original method for biological osteosynthesis and bone reinforcement in children with osteogenesis imperfecta.

PURPOSE: Osteogenesis imperfecta (OI) is a genetic disorder responsible for various symptoms including deformities and frequent fractures. Bone allografting is poorly documented in this condition. The objective of this study was to describe our experience and assessments in a consecutive series of OI patients. METHODS: Thirty-nine lower limb allograft procedures (28 femurs, 11 tibias) were performed in 26OI patients (mean age, 12.9 years). They were classified as type III of Sillence (17), type IV (6), and 3 recessive forms. The indications for surgery were correction of deformity (19), fracture (16), and non-union (4). In all cases, bone allografting was added to reinforce areas of fragility and in 28 cases for osteosynthesis to lock the rotations at the osteotomy site and to avoid screwed metallic plate. The duration of bone consolidation and allograft fusion was assessed. Complications and Gillette functional score were reported. RESULTS: The mean follow-up was 6.7years (range, 2 to 10 years). On average, bone consolidation was achieved after 3.3 months and graft fusion after 7.7 months. No bone allograft-related complications were observed and there was any secondary displacement. The Gillette functional score was improved in 23 patients and stable in three cases. Complications were reported in two cases: one partial allograft resorption and one delayed consolidation of a non-union. One refracture was observed but after a significant trauma in a child who had regained significant physical activity. CONCLUSIONS: Bone allografting in children with OI is a reliable method of biological fixation, allowing efficient fusion and contributing to increased bone capital and functional outcome.

Were protective procedures against SARS-CoV-2 effective in an orthopaedic and trauma centre during the lockdown period? A retrospective study.

PURPOSE: The SARS-CoV-2 epidemic started in December 2019 in Wuhan. The lockdown was declared on March 16, 2020 in France. Our centre had to adapt daily practices to continue to take care of bone and soft tissue tumours and emergencies. Through this study, we wanted to assess the various procedures implemented during the lockdown period between March 17 and May 10. METHODS: A monocentric retrospective cohort study was conducted in Cochin Hospital (Paris, France). Patients included were those who had surgery during the lockdown period. To take care of COVID-19 positive and negative patients, various procedures have been set up: reverse transcriptase polymerase chain reaction (RT-PCR) tests for all hospitalized patients, a specific unit for COVID-positive patients, a specific surgical room, and use of protective personal equipment. To allow the effectiveness of the procedures implemented, we evaluated the number of complications attributed to SARS-CoV-2 and the number of patients who became COVID positive during hospitalization. RESULTS: During the lockdown period, there were 199 procedures of three types of procedures in our centre: 79 traumatology procedures (39.7%), 76 of bone and soft tissues tumours (38.2%), and 44 procedures related to infection (22.1%). We observed 13 complications (6.5%) during hospitalization, and only one patient became COVID-19 positive during the hospitalization. CONCLUSION: The COVID-19 epidemic has been a challenge for organization and adaptation to manage all COVID-19 positive and COVID negative. Through this study, we wanted to assess our procedures taken. They had been effective due to the low number of contamination and complications.

Dual mobility constructs in revision total hip arthroplasty: survivorship analysis in recurrent dislocation versus other indications at three to twelve-year follow-up.

BACKGROUND: The aim of this retrospective study was to evaluate the clinical, radiologic, and survival results of dual mobility (DM) sockets in revision total hip arthroplasty (THA) performed for instability versus revision THAs performed for other reasons. METHODS: From a computerized database, we identified 84 revision THAs using a modern DM socket performed in 81 patients with a mean age of 71 years. Indication for revision was recurrent dislocation in 47 hips, and other reasons in the remaining 37 hips. A survivorship analysis according to the actuarial method was carried out on the entire series using revision for any cause, revision for dislocation, and radiological cup loosening revised or not, as the end points. RESULTS: Of the 81 patients, twelve died, six were lost to follow-up, eight had been revised, and 55 patients (58 hips) were unrevised and alive at a mean follow-up of 6.4 years. Dislocation occurred in four of the 47 (8.5%) hips for which indication for revision was dislocation versus one of the remaining 37 (2.7%) hips [odds ratio = 3.4 (0.4-31.3), p = 0.07]. According to our criteria, three acetabular components of which one was revised were considered as loosened. When using revision for dislocation as the end-point, the survival rate at seven years was 90.4 ± 5.3% (IC95%, 79.9-100) in the 47 hips for which the indication for revision was dislocation versus 100% in the remaining 37 hips (log-rank, p = 0.5). CONCLUSIONS: The current study indicated that DM sockets represent an interesting solution to prevent dislocation in revision THAs at mid-term follow-up.

Corrigendum to "Successful Pelvic Resection for Acetabular Hydatidosis".

[This corrects the article DOI: 10.1155/2017/9495783.].

Free fillet lower leg flap for coverage after hemipelvectomy or hip disarticulation.

INTRODUCTION: Tumor resection is the gold standard treatment for soft tissue and bone sarcomas. In the pelvis, this may require a hemipelvectomy that can compromise primary skin closure. Flaps are essential in this context; however the vascularization of potential pedicled flaps may have been removed during tumor excision. Using healthy tissue from the amputated limb as a free flap is an excellent coverage option. HYPOTHESIS: The free fillet flap from an amputated lower limb is a simple and reliable coverage technique after hemipelvectomy or hip disarticulation. MATERIAL AND METHODS: Seven patients were operated on at three specialty centers: six transpelvic amputations (external hemipelvectomy) and one hip disarticulation. In three cases, the flap consisted of the superficial posterior compartment of the calf area and in the three other cases, the lower leg compartments with the fibula and its intact periosteum. Complications were documented. RESULTS: Clear resection margins were achieved in all patients. The mean follow-up at the final visit was 13 months (range, 6.5 to 21 months). Six patients had complications but only one resulted in loss of the flap. Four patients were able to be fitted with a hip prosthesis. DISCUSSION: The free fillet flap from an amputated lower limb is a reliable coverage technique (86%) after hemipelvectomy or hip disarticulation. In the 16 cases previously reported in the literature, there were no wound-healing failures. Local flaps are often too fragile with insufficient muscular padding. This free flap is the preferred first-line technique as it spares other potential free flaps in case of failure without increasing the morbidity of a procedure that is already extensive. This coverage technique should be one the options considered after external hemipelvectomy. LEVEL OF EVIDENCE: IV, retrospective study.

Successful Treatment of Saksenaea sp. Osteomyelitis by Conservative Surgery and Intradiaphyseal Incorporation of Amphotericin B Cement Beads.

Osteoarticular mucormycosis cases are quite rare and challenging infections that are mostly due to direct inoculation during traumatic injury among immunocompetent patients. Classic management includes a combination of aggressive surgical debridement, which may lead to amputation, and long-term systemic liposomal amphotericin B therapy. This article describes the successful treatment of Saksenaea sp. osteomyelitis in a patient with diabetes mellitus, using a combination of systemic antifungal therapy and conservative surgery with insertion of amphotericin-impregnated cement beads.

Pelvic reconstructions following peri-acetabular bone tumour resections using a cementless ice-cream cone prosthesis with dual mobility cup.

PURPOSE: Despite numerous reconstructive techniques and prosthetic devices, pelvic reconstructions following peri-acetabular malignant tumours resections are highly challenging. In the present study, we describe our experience with the Integra® (Lépine, Genay, France) ice-cream cone prosthesis in such indications. The objective was to assess the mid-term outcomes of this device. METHODS: Twenty-four patients' chart with peri-acetabular malignant tumours, who underwent types II or II + III peri-acetabular resections according to Enneking and Dunham with subsequent reconstruction using the Integra® prosthesis between February 2009 and February 2015, were reviewed. Seventeen cases were primary surgeries and seven cases were revisions (i.e., failures of previous reconstructions for pelvic tumours). All living patients with the prosthesis implanted were functionally assessed, using the musculoskeletal tumour society (MSTS) and Postel-Merle d'Aubigné (PMA) scores. RESULTS: After a mean follow-up of 49 ± 26 months (range, 8 to 94 months), 21 patients were alive (88%), including 15 patients continuously disease-free (63%). MSTS and PMA scores averaged 72 ± 13% (range, 43 to 87%) and 14.6 ± 2.6 (range, 9 to 18), respectively. Fourteen patients (58%) presented at least one complication during follow-up, including four cases of deep infection (17%), four cases of dislocation (17%), and two mechanical failures (8%). At 5 years, the implant survival rate was 75%. CONCLUSIONS: In comparison to previous reconstructive techniques that we used in similar indications, functional and oncologic outcomes were improved with the Integra® implant. However, as commonly observed in pelvic bone tumour surgery, complication rates remain significant. LEVEL OF EVIDENCE: Therapeutic, Level IV-Retrospective Cases Series.

Frontline Science: Human bone cells as a source of IL-27 under inflammatory conditions: role of TLRs and cytokines.

IL-27 regulates immune responses as well as hematopoiesis and bone remodeling, but its cellular sources in the bone remain unknown. In this study, we investigated whether osteoclasts and osteoblasts-the 2 cell types orchestrating bone homeostasis-could be a source of IL-27 and identified stimuli that induce its expression in vitro. We observed that human monocyte-derived osteoclasts expressed a broader range of TLRs than did human primary osteoblasts and that both cell types exhibited a differential induction of IL-27 expression in response to TLR or cytokine stimulation. Whereas several TLR agonists, notably TLR4 and TLR7/8 agonists, induced substantial expression of IL-27 by osteoclasts, stimulation of osteoblasts with agonists of TLR3 and/or TLR4-the 2 TLRs selectively expressed by these cells-resulted in no or low IL-27 expression. In addition, IL-27 increased TLR3 expression in osteoclasts and enhanced poly(I:C)-mediated induction of IL-27 in these cells. IFN-γ, when combined with either IL-1ß plus TNF-α, IL-11, or CNTF, induced significant levels of IL-27 in osteoclasts but not in osteoblasts. In the latter cells, the addition of type I IFN, together with proinflammatory cytokines, was necessary to induce substantial levels of IL-27. Immunohistochemical studies of inflamed and remodeling bone tissue, including cases of infectious osteomyelitis and bone metastases, provided evidence that osteoclasts, osteoblasts, and occasionally osteocytes or chondrocytes, could express IL-27 in situ. This autocrine production of IL-27 by TLR- or cytokine-activated bone cells might constitute a negative-feedback mechanism to limit bone erosion and to dampen T cell-mediated immune pathology during bone inflammation.

Does vitamin E-blended polyethylene reduce wear in primary total hip arthroplasty: a blinded randomised clinical trial.

PURPOSE: Some data indicate that first-generation highly cross-linked polyethylene (HXLPE) can oxidise in vivo and is associated with reduced mechanical properties. To overcome these limitations, a natural anti-oxidant vitamin E has been added to HXLPE to preserve the mechanical properties and decrease oxidative degradation whilst conserving high wear resistance. We hypothesised that after a minimal three years of follow-up the use of vitamin E-blended HXLPE would result in lower radiographic wear when compared with ultra-high molecular weight polyethylene (UHMWPE). METHODS: One hundred patients were randomised to receive hybrid total hip arthroplasty (THA) using a monoblock cementless acetabular component made either of UHMWPE or vitamin E-blended HXLPE. All other parameters were identical in both groups. Complete follow-up was available for 74 of these patients. Femoral head penetration was measured using a validated computer-assisted method. RESULTS: The median creep measured 0.111 mm (range, -0.576 - +0.444 mm) in the vitamin E-blended group versus 0.170 mm (range, -0.861 - +0.884 mm) in the UHMWPE group (difference of medians, 0.059; p = 0.046). The median steady state penetration rate was -0.008 mm/year (range, -0.88 - +0.64 mm/year) in the vitamin E-blended group versus 0.133 mm/year (range, -0.84 - +0.85 mm/year) in the UHMWPE group (difference of medians 0.141, p = 0.043). CONCLUSIONS: This study demonstrated that femoral head penetration was lower when using vitamin E-blended HXLPE when compared with UHMWPE, with a steady-state penetration rate far below the osteolysis threshold. Longer-term follow-up is needed to warrant whether wear reduction will generate less occurrence of osteolysis and aseptic loosening.

Pharmacokinetic variability of clindamycin and influence of rifampicin on clindamycin concentration in patients with bone and joint infections.

PURPOSE: Clindamycin, a lincosamide antibiotic with a good penetration into bone, is widely used for treating bone and joint infections by Gram-positive pathogens. To be active against Staphylococcus spp, its concentration at the infection site, C, must be higher than 2× the minimal inhibitory concentration (MIC). The aims of the work were to study the determinants of plasma clindamycin trough concentration, C min, especially the effect of co-treatment with rifampicin, and the consequences on clinical outcome. METHODS: An observational study was performed, involving patients hospitalized for a bone and joint infection who received clindamycin as part of their antibiotic treatment. Target C min was 1.7 mg/L, to reach the desired bone concentration/MIC >2, assuming a 30% diffusion into bone and MIC = 2.5 mg/L. RESULTS: Sixty one patients (mean age: 56.8 years, 57.4% male) were included between 2007 and 2011. 72.1% underwent a surgery on a foreign material, and 91.1% were infected by at least a Gram-positive micro-organism. Median C min value was 1.39 mg/L, with 58% of the values below the threshold value of 1.7 mg/L. Median C min was significantly lower for patients taking rifampicin (0.46 vs 1.52 mg/L, p = 0.034). No patient with rifampicin co-administration reached the target concentration (maximal C min: 0.85 mg/L). After a median follow-up of 17 months (1.5-38 months), 4 patients relapsed, 2 died and 47 (88.7% of the patients with known outcome) were cured, independently of association with rifampicin. CONCLUSIONS: This study shows the high inter-variability of plasma clindamycin concentration and confirms that co-treatment with rifampicin significantly decreases clindamycin trough concentrations.

The activation of the WNT signaling pathway is a Hallmark in neurofibromatosis type 1 tumorigenesis.

PURPOSE: The hallmark of neurofibromatosis type 1 (NF1) is the onset of dermal or plexiform neurofibromas, mainly composed of Schwann cells. Plexiform neurofibromas can transform into malignant peripheral nerve sheath tumors (MPNST) that are resistant to therapies. EXPERIMENTAL DESIGN: The aim of this study was to identify an additional pathway in the NF1 tumorigenesis. We focused our work on Wnt signaling that is highly implicated in cancer, mainly in regulating the proliferation of cancer stem cells. We quantified mRNAs of 89 Wnt pathway genes in 57 NF1-associated tumors including dermal and plexiform neurofibromas and MPNSTs. Expression of two major stem cell marker genes and five major epithelial-mesenchymal transition marker genes was also assessed. The expression of significantly deregulated Wnt genes was then studied in normal human Schwann cells, fibroblasts, endothelial cells, and mast cells and in seven MPNST cell lines. RESULTS: The expression of nine Wnt genes was significantly deregulated in plexiform neurofibromas in comparison with dermal neurofibromas. Twenty Wnt genes showed altered expression in MPNST biopsies and cell lines. Immunohistochemical studies confirmed the Wnt pathway activation in NF1-associated MPNSTs. We then confirmed that the knockdown of NF1 in Schwann cells but not in epithelial cells provoked the activation of Wnt pathway by functional transfection assays. Furthermore, we showed that the protein expression of active ß-catenin was increased in NF1-silenced cell lines. Wnt pathway activation was strongly associated to both cancer stem cell reservoir and Schwann-mesenchymal transition. CONCLUSION: We highlighted the implication of Wnt pathway in NF1-associated tumorigenesis.

MicroRNAome profiling in benign and malignant neurofibromatosis type 1-associated nerve sheath tumors: evidences of PTEN pathway alterations in early NF1 tumorigenesis.

BACKGROUND: Neurofibromatosis type 1 (NF1) is a common dominant tumor predisposition syndrome affecting 1 in 3,500 individuals. The hallmarks of NF1 are the development of peripheral nerve sheath tumors either benign (dermal and plexiform neurofibromas) or malignant (MPNSTs). RESULTS: To comprehensively characterize the role of microRNAs in NF1 tumorigenesis, we analyzed 377 miRNAs expression in a large panel of dermal and plexiform neurofibromas, and MPNSTs. The most significantly upregulated miRNA in plexiform neurofibromas was miR-486-3p that targets the major tumor suppressor gene, PTEN. We confirmed PTEN downregulation at mRNA level. In plexiform neurofibromas, we also report aberrant expression of four miRNAs involved in the RAS-MAPK pathway (miR-370, miR-143, miR-181a, and miR-145). In MPNSTs, significant deregulated miRNAs were involved in PTEN repression (miR-301a, miR-19a, and miR-106b), RAS-MAPK pathway regulation (Let-7b, miR-195, and miR-10b), mesenchymal transition (miR-200c, let-7b, miR-135a, miR-135b, and miR-9), HOX genes expression (miR-210, miR-196b, miR-10a, miR-10b, and miR-9), and cell cycle progression (miR-195, let-7b, miR-20a, miR-210, miR-129-3p, miR-449a, and miR-106b). CONCLUSION: We confirmed the implication of PTEN in genesis of plexiform neurofibromas and MPNSTs in NF1. Markedly deregulated miRNAs might have potential diagnostic or prognostic value and could represent novel strategies for effective pharmacological therapies of NF1 tumors.

The use of fibre-based demineralised bone matrix in major acetabular reconstruction: surgical technique and preliminary results.

Acetabular osteolysis associated with socket loosening is one of the main long-term complications of total hip arthroplasty. In case of major bone loss, where <50% host bone coverage can be obtained with a porous-coated cementless cup, it is generally agreed that a metal ring or cage in association with a cemented component and allograft bone should be used. In order to promote allograft bone consolidation and incorporation, we have associated demineralised bone matrix (DBM, Grafton® A Flex) to the construct ion. Here we describe the technical details of major acetabular reconstruction using the Kerboull acetabular reinforcement device with allograft bone and DBM. This device has a hook that must be placed under the teardrop of the acetabulum and a plate for iliac fixation. The main advantages of this device are help in restoring the normal centre of hip rotation, guiding the reconstruction and partially unloading the graft. The Kerboull acetabular reinforcement device has provided a 92% survival rate free of loosening at 13-year follow-up in a consecutive series of 60 type III and IV deficiencies. Our preliminary results using DBM indicate faster allograft consolidation and remodelling.

Specific distribution within the Enterobacter cloacae complex of strains isolated from infected orthopedic implants.

Bacteria belonging to the Enterobacter genus are frequently isolated from clinical samples but are unusual causative agents of orthopedic implant infections. Twelve genetic clusters (clusters I to XII) and one sequence crowd (sequence crowd xiii) can be distinguished within the Enterobacter cloacae nomenspecies on the basis of hsp60 sequence analysis, and until now, none of these clusters could be specifically associated with a disease. In order to investigate if specific genetic clusters would be involved in infections of orthopedic material, two series of bacterial clinical isolates identified as E. cloacae by routine phenotypic identification methods were collected either from infected orthopedic implants (n = 21) or from randomly selected samples of diverse anatomical origins (control; n = 52). Analysis of the hsp60 gene showed that genetic clusters III, VI, and VIII were the most frequent genetic clusters detected in the control group, whereas cluster III was poorly represented among the orthopedic implant isolates (P = 0.006). On the other hand, E. hormaechei (clusters VI and VIII), but not cluster III, is predominantly associated with infections of orthopedic implants and, more specifically, with infected material in the hip (P = 0.019). These results support the hypothesis that, among the isolates within the E. cloacae complex, E. hormaechei and hsp60 gene sequencing-based cluster III are involved in pathogenesis in different ways and highlight the need for more accurate routine Enterobacter identification methods.

Ipsilateral femoral autograft reconstruction after resection of a pelvic tumor.

BACKGROUND: Reconstruction of bone after the resection of a pelvic tumor is challenging. The purpose of the present study was to evaluate the use of the ipsilateral femur as the graft material for reconstruction. METHODS: We performed a retrospective review of thirteen patients with a malignant pelvic lesion who underwent resection followed by reconstruction with an ipsilateral femoral autograft and insertion of a total hip replacement. The study group included nine men and four women with a median age of fifty-one years at the time of the reconstruction. The diagnosis was chondrosarcoma in eight patients, metastasis in three, and myeloma and radiation-induced malignant disease in one each. The surviving patients were assessed functionally and radiographically; the cumulative probability of revision was estimated while taking into account competing risks. RESULTS: The median duration of follow-up was forty-nine months. At the time of the latest follow-up, seven patients were alive and disease-free and six had died from metastatic disease. Four patients had had revision of the reconstruction, two for the treatment of mechanical complications and two for the treatment of infection. Three other patients had mechanical complications but had not had a revision. The cumulative probability of revision of the reconstruction for mechanical failure was 8% (95% confidence interval, 0% to 23%), 8% (95% confidence interval, 0% to 23%), and 16% (95% confidence interval, 0% to 39%) at one, two, and four years, respectively. CONCLUSIONS: Although it has attendant complications consistent with pelvic tumor surgery, an ipsilateral femoral autograft reconstruction may be an option for reconstruction of pelvic discontinuity in a subgroup of patients following tumor resection. This innovative procedure requires longer-term follow-up studies.

Acute pancreatitis related to tigecycline: case report and review of the literature.

Tigecycline is a new broad-spectrum antibiotic. Nausea and vomiting are its most common side-effects. We describe here a case of severe acute pancreatitis related to tigecycline in order to highlight the possible occurrence of this adverse event and to remind clinicians to measure the lipase rate if in any doubt.

Allograft-prosthesis composites after bone tumor resection at the proximal tibia.

The survival of irradiated allograft-prosthesis composites at the proximal tibia is mostly unknown. However, allograft-prosthesis composites have proved beneficial at other reconstruction sites. We presumed allograft-prosthesis composites at the proximal tibia would improve survival and facilitate reattachment of the extensor mechanism compared with that of conventional (megaprostheses) reconstructions. We retrospectively reviewed 26 patients who underwent resection of proximal tibia tumors followed by reconstruction with allo-graft-prosthesis composites. Patients received Guepar massive custom-made fully constrained prostheses. Allografts were sterilized with gamma radiation, and the stems were cemented into the allograft and host bone. The minimum followup was 6 months (median, 128 months; range, 6-195 months). Fourteen patients had one or more components removed. The median allograft-prosthesis composite survival was 102 months (95% confidence interval, 64.2-infinity). Of the 26 allografts, seven fractured, six showed signs of partial resorption, and six had infections develop. Seven allografts showed signs of fusion with the host bone. Six extensor mechanism reconstructions failed. Allograft-prosthesis composites sterilized by gamma radiation yielded poor results for proximal tibial reconstruction as complications and failures were common. We do not recommend irradiated allograft-prosthesis composites for proximal tibia reconstruction.