Aim. Repeat revision surgery of total hip or knee replacement may lead to massive bone loss of the femur. If these defects exceed a critical amount a stable fixation of a proximal or distal femur replacement may not be possible. In these extraordinary cases a total femur replacement (TFR) may be used as an option for limb salvage. In this retrospective study we examined complications, revision free survival (RFS), amputation free survival (AFS) and risk factors for decreased RFS and AFS following a TRF in cases of revision arthroplasty with a special focus on periprosthetic joint infection (PJI). Method. We included all implantations of a TFR in revision surgery from 2006–2018. Patients with a primary implantation of a TFR for oncological indications were not included. Complications were classified using the Henderson Classification. Primary endpoints were revision of the TFR or disarticulation of the hip. The minimum follow up was 24 month. RFS and AFS were analyzed using Kaplan-Meier method, patients´ medical history was analyzed for possible risk factors for decreased RFS and AFS. Results. After applying the inclusion criteria 58 cases of a TFR in revision surgery were included with a median follow-up of 48.5 month. The median age at surgery was 68 years and the median amount of prior surgeries was 3. A soft tissue failure (Henderson Type I) appeared in 16 cases (28%) of which 13 (22%) needed revision surgery. A PJI of the TFR (Henderson Type IV) appeared in 32 cases (55%) resulting in 18 (31%) removals of the TFR and implantation of a total femur spacer. Disarticulation of the hip following a therapy resistant PJI was performed in 17 cases (29%). The overall 2-year RFS was 36% (95% confidence interval(CI) 24–48%). Patients with a Body mass Index (BMI) >30kg/m² had a decreased RFS after 24 month (>30kg/m² 11% (95%CI 0–25%) vs. <30kg/m² 50% (95%CI 34–66%)p<0.01). The overall AFS after 5 years was 68% (95%CI 54–83%). A PJI of the TFR and a BMI >30kg/m² was significantly correlated with a lower 5-year AFS (PJI 46% (95%CI 27–66%) vs no PJI 100%p<0.001) (BMI >30kg/m² 30% (95% KI 3–57%) vs. <30km/m² 85% (95% KI 73–98%)p<0.01). Conclusions. A TFR in revision arthroplasty is a valuable option for limb salvage but complications in need of further revision surgery are common. Patients with a BMI >30kg/m² should be informed regarding the increased risk for revision surgery and loss of extremity before operation

Purpose: Replacing the entire femur for primary bone tumour is exceptional. Prostheses used in this series were custom-made by Link using the Endo Klinik (Hambourg) model. These prostheses have adjustable ante-version and a hinge type knee with rotation. Patients and Results: Case n° 1. A 15-year-old boy, grade 2A osteosarcoma in the diaphyseal zone of the lower femur. Rosen chemotherapy. En bloc resection. Total femur prosthesis sleeved onto the trochanteric mass left in place. Excellent response:100%. Excellent functional result: mountain climbing! Current status: recurrence-free, metastasis-free at 16 years follow-up. Case n° 2. Adult osteosarcoma. 68-year-old woman with pulmonary metastasis at diagnosis. Indication due to fracture to mid third of femur. Excellent immediate result. Nine-month survival in very satisfactory condition. Case n° 3. 72-year-old woman treated one year earlier for T1N0M0 breast cancer. Metastatic image in the trochanter. Treatment by curettage and THA. Histology reported chondrosarcoma. Scintigraphy showed uptake in gluteus medius and the lower part of the femur. En bloc resection of entire femur and gluteus medius. Total femur replacement with prosthesis sleeved onto an allograft. Complete resection. Current status: recurrence-free, metastasis-free at five years. No limitation on walking distance. Walks with cane due to moderate limp. Case n° 4. Adult osteosarcoma (32 years). Low-grade tumour (1B) occupying the entire femur. Rizzoli Institute chemotherapy protocol. Resection and total femur replacement with prosthesis sleeved onto an allograf. Complete resection. Poor response. Excellent functional result, persistence of minimal limp. Active tumour with pulmonary metastasis at one year and death at 1.5 yers. Case n° 5. Grade 2B osseous leiomyosarcoma in the diaphyseal zone of the lower femur in a 37-year-old woman. Neoadjuvant chemotherapy followed by total femur resection. Excellent responder:100%. Excellent functional outcome at short follow-up (1 year). Discussion: Total femur replacement with a prostheses sleeved on an allograft allows reinsertion of the gluteus medius and the psoas. This method is reliable and avoids major instability. Complications in this small number of patients were rare and were not serious. The functional results have been excellent and appear to depend primarily on the importance of muscle resection required to achieve tumour resection

Introduction: Implant loosening/pseudartrhosis after THR/TKR with large femoral bone defects is associated with pain and immobilization in a wheelchair. In these cases a total femur replacement (Combined total hip and knee replacement connected with an intramedullary rod) can be a therapeutic procedure as known from tumor surgery. We describe this technique and results with in a case serie of patients. Study Type: Monocentric prospective case serie. Patients and Methods: All patients who had a total femur replacement were followed regularly after 3, 6 months, 1, 3 and 5 years. The follow up was documented with clinical examination, x-rays and validated questionnaires. Indications were loosening after stem revisions (THR), pseudarthrosis and loosening of femoral component after TKR, pseudarthrosis and instability after THR and fracture. For every case the implants were planned with a total leg x-ray and manufactured (Link). The implants were removed and the knee and hip joint prepared. The approach was performed with two incisions (knee, hip) to reduce the invasivity. The implantation started with the knee implants connected with the intramedullary rod and was finished with the hip implants. Postoperative weight bearing was following pain. Results: Included were 5 cases of total femur replacement in 4 patients (three women, age from 54 to 69) with a follow up between 12 to 94 months, average 3.5 years. Three cases with stem loosening after THR and revisions before, one case with loosening and pseudarthrosis after TKR, one with pseudarthrosis and instability after THR with femur fracture. Every patient had 2–4 interventions of the affected joint before. The pain diminuished significant in all patients in the questionnaires and the pain medication could be reduced substantially. All patients gained mobility already three months after the procedure, every patient could walk with crutches. No patients needed to be reoperated in the follow-up period. Every patient could keep the mobility over the the follow-up time. Two patients reported some pain in the knee. Radiologically the defects of the femur were partially consolidated and we could not see further bone loss. Conclusion: Total femur replacement can be used also in selected patients with large bone defects after arthroplasty (THR/TKN) and loosening or pseudarthrosis. The patients profit from the reduction of pain and the gain in mobility

Background: Limb preserving surgery in patients with tumours involving the whole femur present a formidable challenge. Results: We present our experience of treating such patients with total femur endoprostheses over the last 30 years (1975 to 2005). There were twenty six consecutive patients including 14 males and 12 females. Average age was 40 years (14 – 82 years) at the time of surgery. Eleven patients were still alive of which nine were free of disease at the time of review. The mean follow-up was 57 months (3 to 348). Using Kaplan Meier estimates, the long-term patient survival at 10 years was 37%. The survival of patients with primary localised tumour was 50% at 10 years. Revision of the prostheses was necessary in two patients at 110 and 274 months after surgery because of recurrent dislocation in one and aseptic loosening of the acetabular cup and tibial stem in the other. Amputation was necessary in two patients, one due to deep infection and the other due to local recurrence. The long-term limb survival being 92% at 10 years. Nine patients who were alive with no evidence of disease were assessed for function of the salvaged limbs using the musculoskeletal tumour society (MSTS) rating system. The mean functional score was 72%. Conclusion: We conclude that total femur endoprosthetic replacement offers an excellent method of limb reconstruction following excision of the whole femur either for primary or metastatic tumours. However, patients survival after such operation is poor due to disease related factors

Aims

The transepicondylar axis is a well-established reference for the determination of femoral component rotation in total knee arthroplasty (TKA). However, when severe bone loss is present in the femoral condyles, rotational alignment can be more complicated. There is a lack of validated landmarks in the supracondylar region of the distal femur. Therefore, the aim of this study was to analyze the correlation between the surgical transepicondylar axis (sTEA) and the suggested dorsal cortex line (DCL) in the coronal plane and the inter- and intraobserver reliability of its CT scan measurement.

Limb salvage in musculoskeletal tumor surgery may be complicated by infection. With the advent of modern techniques and medical management limb sparing surgeries can be considered as an alternative to ablation. Between 1992 and 2014, 17 patients were treated for infected megaprostheses after being surgically treated for musculoskeletal tumors. There were nine females and eight males. The mean time from the index procedure until infection was 30 months. Following radical debridement, the resultant skeletal defect averaged 30 cm. Patients were treated with local antibiotics in polymethyl methacrylate (PMMA) spacers and endoprostheses as well as IV antibiotics for a minimum of six weeks followed by oral antibiotics for an additional six weeks. The initial tumor procedure involved the femur in eleven patients, the tibia in two, the acetabulum in one, the humerus in two, and the ulna in one. Patients had repeat cultures before two-stage reimplantation when their WBC, ESR, and CRP returned to normal. Patients were reimplanted when final cultures were negative. Thirteen patients were treated using a two-stage protocol with customized intraoperative antibiotic impregnated PMMA spacers including intramedullary nails for a mean of 10 months and the other four patients had a one-stage procedure. These four patients included two patients with a total femur replacement and two patients with an allograft-prosthetic composite of the proximal humerus and ulna. The organisms cultured were gram positive in 14 cases, mixed gram positive and negative in one case, and two patients had no growth on cultures but histologic evidence of acute infection. Reimplantation was successful in 13 patients after the initial procedure (76%). Four patients had recurrent infections. One of these patients was successfully reimplanted after a one-stage procedure, two had a second two-stage procedure and have retained their spacers, and one had an amputation. Successful limb salvage in regards to infection control occurred in 14/17 patients (82%). One additional patient required an amputation for an oncologic complication (local recurrence), so the overall limb salvage rate was 13/17 (76%). Patients with megaprosthetic infections following limb salvage treatment for musculoskeletal tumors do not have to be uniformly subject to amputation. Radical debridement and appropriate antibiotics in conjunction with custom spacers followed by selective one- and two-stage reimplantation results in successful limb salvage in 82% of patients. This result is similar to other reports despite the large size average defects

Massive proximal femoral bone loss can be a complex problem, despite various modern technical and implant solutions. Due to inadequate bone stock and missing proximal fixation possibilities, including larger segmental osseous defects, the use of a mega prosthesis might become necessary. Coverage of the segmental bone loss in combination with distal fixation, can be achieved in either cemented or non-cemented techniques. Some implant types allow for additional fixation of the gluteal muscles, attached with non-absorbable sutures or synthetic mesh grafts. Although first reports about partial or even complete femoral replacement are available since the 1960's, larger case series or technical reports are rare within the literature and limited to some specialised centers. Most series are reported by oncologic centers, with necessary larger osseous resections of the femur. The final implantation of any mega prosthesis system requires meticulous planning, especially to calculate the appropriate leg length of the implant and resulting leg length. Combination of a posterior hip with a lateral knee approach allows for the enlargement to a total femur replacement, if necessary. The lateral vastus muscle is detached and the entire soft tissues envelope can be displaced medially. After implant and cement removal, non-structural bone might be resected. Trial insertion is important, due to the variation of overall muscle tension intraoperatively and prevention of early or late dislocation. Currently the use of proximal modular systems, including length, offset and anteversion adaption, became the technique of choice for these implant systems. However, just very few companies offer yet such a complete system, which might also be expanded to a total femur solution. We were able to evaluate our Endo-Klinik results of total-femur replacements within 100 consecutive patients in non-infected cases, after a mean follow up time of five years. There we “only” 68% patients without complications, main complications included: 13% revealed a deep infection; dislocation was found in 6%, material failure and consequent breakage in 3%, persistent patellar problems in 2% and finally 1% with peroneal nerve palsy. These results show that a total-femur replacement is associated with a high complication rate, even in non-infected patient cohorts

The aim of this study was to analyze the frequency and reveal the most common reasons of the endoprosthetic instability in patients with malignant bone tumors. From 1992 – 2008, 625/515 patients, endoprosthetic replacement of major joints were performed. The median age of the patients was 30.3 years (13 to 72 years). Aseptic instability was observed after 3/71(4.2%) humeral joint replacement out of total operations at this location, after 4/80 (5%) hip prosthesis, after 19/133 (14%) proximal tibial prostheses, after 44/299 (14.7%) distal femoral prostheses and after 2/37 (5.4%) total femur replacements. The retrospective analyses has shown that the reasons of instability were the following: aseptic loosening of the stems of endoprosthesis in 26 cases (24.4%), stem break in 31 (36.1%), endoprosthetic unit destruction in 10 (11.6%), untwistment of fixational screws in 10 (11,6%), migration of hip endoprosthesis components in 2 (2.3%) and endoprosthesis dislocation in 12 (14%). The timing of endoprosthetic instability ranged from 7 days to 12.2 years (average 26.2 months). Statistic analyses was performed in a group of patients with aseptic endoprosthesis instability developed after proximal tibia and distal femur resection. We conclude that the most frequent reason of aseptic instability was endoprosthetic stem break. The instability rate was actually lower among the patients who had underwent 5–10cm distal tibia resection comparing with the group of 10–15cm bone mass resection (p=0.05). Femoral resection enhanced the instability frequency comparing with proximal tibia resection in the group of 5–10cm bone mass resection (p=0.05)

The use of megaprosthesis presents a major advancement in orthopaedic oncology in the treatment of malignant bone and soft tissue tumours. In the present study, we retrospectively analyse the complication rate of limb salvage surgery with megaprosthesis due to malignant tumours treated in our unit. From 1997 until 2006, 64 patients (37 men, 27 women), aged between 16–78 years old (mean 43.3), have been treated with megaprosthesis insertion. The diagnosis was metastatic bone lesions in 26 patients, osteosarcoma in 14, chondrosarcoma in 14, soft tissue sarcoma with osseous involvement in 3 (2 synovial sarcoma and 1 MPNST), malignant giant cell tumour in 3, angiosarcoma in 2, Ewing sarcoma in 1, and revision of a failed reconstruction in 1 patient. Lower extremity reconstruction included proximal femur (30 patients), distal femur (19), proximal tibia (3) and total femur replacement (4). Upper extremity procedures were proximal humerus (7 patients) and distal humerus reconstruction (1). Sixty patients were available for follow-up (minimum 1 year, mean 4.2 years). The following complications were encountered: periprosthetic fracture (1 patient), deep infection (4), superficial wound infection (6), local recurrences (2), hip dislocation (3), knee extensor apparatus failure (2), skin necrosis, (3) unsuccessful vascular reconstruction (1). The deep infection led to hip disarticulation in 1 patient and Tikhoff-Linberg resection in 1 patient with proximal humerus prosthesis. A rare case of bone leismaniasis was also encountered (treated conservatively). Limb salvage surgery is the mainstay of treatment in malignant musculoskeletal tumours. Special megaprosthesis has been developed for this purpose. Survival rate is substantially less than common prosthesis; the complication rate is increased, especially regarding wound healing complications and infection. Adverse prognostic factors are:. a) advanced age,. b) the amount of soft tissues that need to be excised,. c) prolonged surgical time, and. d) reconstruction about the knee

The October 2015 Oncology Roundup³⁶⁰ looks at: Radiotherapy for the radioresistant; Multiple hereditary exostosis; The total femur as a limb salvage option; Survival prediction in osteosarcoma; What happens when chondrosarcoma recurs?; Thumbs up for vascularised fibular graft; Radiotherapy and survival; Musculoskeletal tumours in pregnancy

The October 2013 Oncology Roundup³⁶⁰ looks at: En bloc resection, irradiation and re-implantation; Metastasis and osteosarcoma; Mobile spine and osteosarcoma; Denosumab miraculous for GCT; Fevers, megaprostheses and sarcomas; PET and prognosis; Canine sarcomas not so different?; Bone cement and giant cell tumours.