Proximal Femoral Replacement Research Articles

Revision total hip arthroplasty after removal of a fractured well-fixed extensively porous-coated femoral component using a trephine.

When fracture of an extensively porous-coated femoral component occurs, its removal at revision total hip arthroplasty (THA) may require a femoral osteotomy and the use of a trephine. The remaining cortical bone after using the trephine may develop thermally induced necrosis. A retrospective review identified 11 fractured, well-fixed, uncemented, extensively porous-coated femoral components requiring removal using a trephine with a minimum of two years of follow-up. The mean time to failure was 4.6 years (1.7 to 9.1, standard deviation (sd) 2.3). These were revised using a larger extensively porous coated component, fluted tapered modular component, a proximally coated modular component, or a proximal femoral replacement. The mean clinical follow-up after revision THA was 4.9 years (2 to 22, sd 3.1). The mean diameter of the femoral component increased from 12.7 mm (sd 1.9) to 16.2 mm (sd 3.4; p > 0.001). Two revision components had radiographic evidence of subsidence that remained radiographically stable at final follow-up. The most common post-operative complication was instability affecting six patients (54.5%) on at least one occasion. A total of four patients (36.4%) required further revision: three for instability and one for fracture of the revision component. There was no statistically significant difference in the mean Harris hip score before implant fracture (82.4; sd 18.3) and after trephine removal and revision THA (81.2; sd 14.8, p = 0.918). These findings suggest that removal of a fractured, well-fixed, uncemented, extensively porous-coated femoral component using a trephine does not compromise subsequent fixation at revision THA and the patient's pre-operative level of function can be restored. However, the loss of proximal bone stock before revision may be associated with a high rate of dislocation post-operatively.

Management of femoral bone loss in revision total hip arthroplasty.

Femoral bone loss is frequently encountered during revision total hip arthroplasty. The quality and quantity of remaining bone helps determine the best method for reconstruction. Extensively porous-coated cylindrical stems or titanium fluted tapered devices that achieve fixation in the diaphysis have both demonstrated excellent long-term survivorship. Titanium fluted tapered stems with a modular proximal body allow for more accurate leg length, offset, and version adjustments independent of the distal stem which may optimise hip biomechanics. Intraoperative fractures are more common with cylindrical stems and subsidence with tapered stems, particularly monoblock designs and in both dislocation continues to be one of the most common postoperative complications. In salvage situations in which an ectatic femoral canal is unable to support an uncemented device, impaction bone grafting, allograft-prosthetic composite, or a segmental proximal femoral replacement may be required.

CORR Insights(®): High Survivorship With Cementless Stems and Cortical Strut Allografts for Large Femoral Bone Defects in Revision THA.

Where Are We Now? Femoral bone loss is frequently encountered during revision THA. The key is determining the quality and quantity of bone loss, as well as quality and quantity of remaining host bone. In contemporary North American practices, diaphyseal fixation with either an extensively porous-coated stem or titanium modular fluted tapered (TMFT) stem is the standard of care for the majority of hips with bone defects rated Paprosky Type IIIB or less. The basic principle in both techniques is the importance of obtaining immediate axial and rotational stability. The two main clinical concerns with extensively porous-coated stems are intraoperative periprosthetic femoral fracture and stress shielding over time. In response to these concerns, the interest in TMFT stems is increasing, and the indications for their use seem to be expanding [1]. The real controversy is in those patients with Paprosky Type IV defects in whom rotational stability in the diaphysis would not be possible to obtain. In this difficult setting, consideration has traditionally been given to allograft-prosthetic composites (APCs), impaction bone grafting with long cemented stems, proximal femoral replacements, and more recently, TMFT stems. In this intriguing paper by Kim et al., the authors studied 130 patients (140 hips) with Paprosky Type IIIB (54%) and Type IV (46%) defects who underwent revision THA. Even though all patients had less than 2 cm of available isthmic bone, the surgeons used extensively porous-coated stems. However, cortical strut allografts (one strut in 10%, two struts in 75%, and three struts in 15%) were used to provide primary stability for the extensively porous-coated stems. At a mean followup of 16 years, the authors found that all allografts had incorporated, and 87% of stems had radiographic evidence of bony ingrowth. Where Do We Need To Go? When massive bone loss is encountered during revision THA, structural allografts are often a helpful technique. However, followup radiographic analysis of strut incorporation is complicated, and alternative approaches are required to see if these devices are indeed well-fixed. Moreover, deep periprosthetic infection in revision surgery remains a paramount concern to patients and surgeons alike. This may influence the liberal use of struts, particularly in those patients undergo reimplantation THA. Finally, additional investigations comparing the results of patients with prior cemented and uncemented stems are needed given that the remaining host bone quality is starkly different. How Do We Get There? Given the complicated nature of radiographically analyzing strut incorporation, retrieval studies investigating the interface between the cortical strut allograft and an extensively porous-coated stem, as well correlation with radiographic findings, will be helpful in determining where bony ingrowth occurs (if at all). In addition, with infection being one of the most common reasons for femoral component revision, the results of the proposed technique by Kim et al. in septic cases must be studied. Finally, a comprehensive and large-scale analysis of contemporary stems, such as the TMFT stem, will be essential to determine if outcomes vary based upon prerevision diagnosis, particularly between failed cemented and uncemented stems. This will likely require either a multicenter investigation, or large national registries such as the American Joint Replacement Registry, to complete. I suspect that as the body of evidence continues to grow on TMFT stems in Paprosky Type IV defects, their popularity will continue given their larger diameters, as well as the ability to adjust leg length, offset, and version independent of diaphyseal fixation.

High Survivorship With Cementless Stems and Cortical Strut Allografts for Large Femoral Bone Defects in Revision THA.

Numerous studies have investigated the clinical and radiographic results of revision THAs with use of cementless stems and cortical strut allografts. However, to our knowledge, no long-term followup studies have evaluated patients undergoing revision THA with use of cortical strut allografts where the allografts provided the primary stability for extensively coated femoral stems in the presence of extensive femoral diaphyseal bone defects. We performed this study to determine (1) validated outcomes scores; (2) radiographic signs of fixation and allograft healing; (3) frequency of complications; and (4) survivorship of the components after use of cortical strut onlay allografts in Types IIIB and IV femoral diaphyseal bone defects. Between 1994 and 2003, we performed 140 revision THAs in 130 patients with Paprosky Types IIIB and IV femoral diaphyseal defects. The patients were treated using extensively coated femoral stems and cortical strut allografts because primary axial or rotational stability could not be achieved without grafting. Ten of the patients (10 hips; 7.7%) were lost to followup or died before 10 years; the remaining 120 patients (130 hips) represent the study group in this retrospective study. There were 66 men and 54 women. Their mean age at the time of index surgery was 59 ± 18 years (range, 36-67 years). The primary diagnosis was predominantly osteonecrosis of the femoral head (53%). The most common reason for revision was aseptic loosening (97%), followed by periprosthetic fracture (3%). The mean time from primary to revision THA was 12 years (range, 8-27 years). The mean duration of followup was 16.1 years (range, 12-20 years). The mean Harris hip score was 39 ± 10 points before revision and improved to 86 ± 14 points at 16 years followup (p = 0.02). The mean preoperative WOMAC score was 62 ± 29 (41-91) points and improved to 22 ± 19 (11-51) points at 16 years followup (p = 0.003). Of the 130 stems, 113 (87%) had bone ingrowth, five (4%) had stable fibrous ingrowth, and 12 (9%) were unstable. All allografts were incorporated. Four hips (3%) had a displaced femoral shaft fracture at the stem tip; four (3%) had a postoperative dislocation; and six (5%) had early postoperative infection. Kaplan-Meier survivorship analysis, with revision or radiographic failure as the endpoint, revealed that the 16-year rate of survival of the components was 91% (95% CI, 0.88%-0.96%). Supportive cortical strut onlay allografts provided high survivorship beyond 12 years of followup in revision THAs. Future studies might compare this approach with allograft-prosthesis composites, proximal femoral replacement, or modular fluted, tapered stems. Level IV, therapeutic study.

(vi) Endoprosthetic replacement of the proximal femur

Abstract Poor bone quality is a risk factor for failure in revision hip arthroplasty. Severe bone loss situations (Paprosky IV) require unique and innovative solutions, building on the experience in oncology where proximal femoral replacement and endoprosthetic reconstruction is a common procedure. Large amounts of bone loss from a variety of aetiologies can be reliably dealt intraoperatively, with on-table modularity in the implant range, extending to total femoral reconstruction. Techniques of exposure and reconstruction, though initially daunting, are in reality straightforward and are described. Previous concerns about high rates of complications such as instability at the hip joint have been significantly reduced by the use of careful soft tissue closure, large head (>36 mm), bipolar and dual mobility articulations.

Implant Fracture after Long-Stemmed Cemented Hemiarthroplasty for Oncologic Indications.

Although a long-stemmed cemented hemiarthroplasty is frequently recommended for oncologic lesions of proximal femur, we have observed an alarming number of spontaneous stem fractures. The purpose of this retrospective study was to identify the associated risk factors for stem fractures in a study cohort of 60 (61 prostheses) during 1983-2007. At a mean follow-up of 41 months, 4/61 (6.6%) stems had fractured after a mean of 36 (12-92) months after surgery. All failed implants were Osteonics Omnifit (4/27; 14.8%) and multivariate analysis did not show any correlation with other studied variables. While the failures were successfully salvaged by conversion to a modular proximal femoral replacement, any implant failure in this population is devastating. Spontaneous onset of thigh pain in patients with long stems, particularly if associated with other risk factors, should raise suspicion of a fatigue fracture of the stem.

Salvage of Failed Total Hip Arthroplasty With Proximal Femoral Replacement

As a result of reading this article, physicians should be able to: 1. Identify the available types of reconstruction for failed total hip arthroplasty. 2. Summarize the preoperative workup of patients with failed total hip arthroplasty and massive proximal femoral bone loss. 3. Assess the surgical technique of proximal femoral replacement for failed total hip arthroplasty. 4. Recognize treatment complications, patient outcomes, and survival of proximal femoral megaprostheses for revision of failed total hip arthroplasty. Despite recent advances in device manufacturing and surgical techniques, the management of proximal femoral bone loss in revision total hip arthroplasty remains challenging. Currently, failed total hip arthroplasty in elderly and less active patients, nonunion of the proximal femur with multiple failed attempts at osteosynthesis, resection arthroplasty, and massive proximal femoral bone loss can be salvaged with proximal femoral replacement using a megaprosthesis. The procedure is technically demanding and requires careful preoperative planning. Instability and aseptic loosening are the major complications, especially in younger and more active patients. The new generation of modular proximal femoral replacement megaprostheses and the increased experience obtained with these surgeries have reduced complication rates and improved outcomes.

Management of complications in megaprostheses

Megaprostheses are frequently used after segmental resection of bone sarcomas, bone metastases, and in large osseous defects in revision arthroplasty. The incidence of the most common complications associated the use of megaprostheses are reported. The management of complications including therapeutic recommendations are described. The current knowledge and our own experience of complication management with the use of megaprostheses are presented. Prospective, randomized studies or meta-analyses on this topic are lacking. An analysis of the literature shows that beside the occurrence of a local recurrence, periprosthetic infection remains the most serious complication. Two-stage revision remains the gold standard, but a single-stage exchange of the prosthesis without removing the stems might be possible in selected cases. Infection is associated with a higher risk of secondary amputation. In contrast, mechanical failures (e.g., wear of the bushings in knee replacements and aseptic loosening of the stems) can be treated more easily. Dislocation of a proximal femur replacement can mostly be prevented by using bi- or tripolar cups. Complications with the use of megaprostheses can be successfully treated by revision surgery in most cases.

Incidence and management of hip dislocation in tumour patients with a modular prosthesis of the proximal femur.

Little data is available about the incidence and especially the management of hip dislocation following the implantation of modular tumor prostheses of the proximal femur. In this retrospective single-centre study we assessed the incidence of hip dislocation following implantation of a proximal femoral modular prosthesis as well as the success of the subsequent surgical or non-surgical treatment in tumor patients. Between 1982 and 2008, 166 tumor patients received a modular prosthesis of the proximal femur at our institution. The average age at the time of surgery was 50 ± 20 years (range, six to 84 years). An additional pelvic reconstruction was done in 14 patients. An artificial band for soft tissue reconstruction of the hip was used in 19 patients. The average time of follow-up was 46 ± 64 months (range, one to 277 months). The overall dislocation rate after proximal femoral replacement was 13% after a mean time of seven ± eight months (range, 0.3-33 months) after surgery. Between 1982 and 1986 the dislocation rate was 33% and declined to 9% in subsequent years (1987-2008). Patients who had received an additional pelvic reconstruction had a three fold higher dislocation rate (p <0.05). Patients with closed reduction had a 58% (eight of 12) re-dislocation rate compared to 11% (one of nine) for open reduction (p = 0.0357). Dislocation of a modular prosthesis of the proximal femur is a common complication, especially in cases with additional pelvic resection with extensive bone and soft-tissue defects. Open surgical management may be more effective in preventing re-dislocation than closed reduction and bracing alone.

What are the functional outcomes of endoprosthestic reconstructions after tumor resection?

The majority of published functional outcome data for tumor megaprostheses comes in the form of subjective functional outcome scores. Sparse objective data exist demonstrating functional results, activity levels, and efficiency of gait after endoprosthetic reconstruction in patients treated for orthopaedic tumors. Patients embarking on massive surgical operations, often in the setting of debilitating medical therapies, face mortality and a myriad of unknowns. Objective functional outcomes provide patients with reasonable expectations and a means to envision life after treatment. Objective outcomes also provide a means for surgeons to compare techniques, rehabilitation protocols, and implants. We asked the following questions: (1) What is the efficiency of gait (ie, oxygen consumption) at final recovery from endoprosthetic reconstruction for oncologic resections? (2) What is the knee strength after lower extremity endoprosthetic reconstruction as compared with the contralateral limb? (3) How active are patients with tumor megaprostheses at home and in the community? Sixty-nine patients with endoprosthetic reconstructions for primary lower extremity bone sarcoma met inclusion criteria and were invited by mailing to undergo oxygen cost study and strength testing. Twenty-four patients (seven proximal femoral replacements, nine distal femoral replacements, and eight proximal tibia replacements) underwent evaluation in the gait laboratory at a mean of 13.2 years after their reconstruction. All patients were then asked to wear step activity monitors at home and in the community for 7 consecutive days. Median O2 consumption (in mL/kg/m) among the endoprothesis groups was not different from the control patients with the numbers available (proximal femoral replacement 0.17, distal femoral replacement 0.16, proximal tibia replacement 0.18, control 0.15, p = 0.21). With the numbers available, there was no difference in walking speed as compared with the control group (proximal femoral replacement 1.20 m/s, distal femoral replacement 1.27 m/s, proximal tibia replacement 1.12 m/s, control 1.27 m/s, p = 0.08). Patients with proximal tibia replacements had reduced knee extension and flexion strength compared with patients in other reconstruction groups (84% reduction in extension versus those with proximal femoral replacements, 35%, and distal femoral replacement, 53%, p = 0.001, and 43% reduction in flexion versus proximal femoral replacement, 11%, distal femoral replacement, 2%, p = 0.006). With the numbers available, mean strides per day were not different among the reconstruction groups (proximal femoral replacement = 4709 strides/day [3094-6696], distal femoral replacement = 2854 [2461-6015], and proximal tibia replacement = 4411 [3093-6215], p = 0.53). Although knee strength was reduced in patients with proximal tibia replacements compared with femoral reconstructions, all groups had an efficient gait and were active at home and in the community at a mean of 13.2 years after surgery. Despite the magnitude of these surgeries, these patients are similarly active as patients after standard total hip arthroplasty. These findings provide objective data from which patients undergoing tumor megaprosthesis reconstructions of the lower extremity can reasonably base expectations of efficient gait and active lifestyles outside of the hospital setting. These data may provide hope and long-term goals for patients facing the uncertainty of chemotherapy and surgical treatment. Level III, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Proximal Femoral Reconstruction With a Constrained Acetabulum in Oncologic Patients

Metallic endoprostheses are used for oncological reconstruction around the proximal femur and hip joint. Common modes of failure with hemiarthroplasty or standard hip arthroplasty after proximal femoral replacement include dislocation, late hip pain, and infection. The authors reviewed hospital records to identify patients undergoing constrained tripolar hip arthroplasty for oncological reasons between 2002 and 2012. Inclusion criterion was at least 12-cm proximal femoral resection, including patients with total femur reconstruction. A total of 33 patients were reviewed. Information regarding demographics, length of follow-up, treatment characteristics, and patient outcomes was extracted. Average follow-up for all patients was 912.33 days (30.4 months). Average follow-up was 1396.1 days for living patients and 428.6 days for deceased patients. Average estimated blood loss was 462.12 cc: an average of 1080 cc for patients undergoing total femoral resection and replacement and 315.8 cc for patients undergoing proximal femoral resection and replacement. Average operative time was 137.7 minutes: an average of 205 minutes for patients undergoing total femoral resection and replacement and 119.1 minutes for patients undergoing proximal femoral resection and replacement. Average Musculoskeletal Tumor Society score was 21.7. There were no dislocations in the cohort. A constrained tripolar device can be safely used for oncological proximal femoral reconstructions while minimizing the risk of dislocation. Positioning of the acetabular implant in neutral anatomic version in conjunction with a neutral-placed femoral component provides the greatest range of motion, reduction of liner impingement, and improved hip stability.

Proximal femoral reconstruction after aseptic loosening following proximal femoral replacement for Ewing sarcoma: a case report with one-year follow-up

We report the case of a 30-year-old patient initially treated for a proximal femoral Ewing's sarcoma when 12 years old. Index treatment comprised tumour resection and total hip arthroplasty. Two years later revision for aseptic loosening was performed. Subsequently, six further surgical revisons were performed for varying causes. At the age of 23 years the proximal femur was resected and a proximal femoral endoprosthesis implanted.Eighteen years after initial diagnosis the patient presented with recurrent aseptc loosening. Both the proximal femur and acetabulum were reconstructed. For acetabular reconstruction a structural allograft and a tantalum cup were utilised. Reconstruction of the femur utilsed extensive wire mesh and circlage wiring with impaction bone allograft into which a femoral stem was implanted.At one-year follow-up the patient was pain free, had no evidence of infection with satisfactory radiographs and no evidence of implant loosening. This is the first case reporting an extended proximal femoral reconstruction with a wire mesh in combination with impaction bone grafting in an aseptic loosened proximal femoral replacement following Ewing's Sarcoma.

Influence of stem design on the primary stability of megaprostheses of the proximal femur

Extended bone defects of the proximal femur can be reconstructed by megaprostheses for which aseptic loosening constitutes one of the major failure modes. The basic requirement for long-term success of endoprostheses is primary stability. We therefore assessed whether sufficient primary stability can be achieved by four different megaprostheses in a standardised bone defect of the proximal femur and whether their different design leads to different fixation patterns. Four different designs of proximal femoral replacements were implanted into 16 Sawbones® after preparing segmental bone defects (AAOS type II). Primary rotational stability was analysed by application of a cyclic torque of ±7 Nm and measuring the relative micromotions between bone and implant at different levels. The main fixation zones and differences of fixation patterns of the stem designs were determined by an analysis of variance. All four implants exhibited micromotions below 150 μm, indicating adequate primary stability. Lowest micromotions for all designs were located near the femoral isthmus. The extent of primary stability and the global implant fixation pattern differed considerably and could be related to the different design concepts. All megaprostheses studied provided sufficient primary stability if the fixation conditions of the femoral isthmus were intact. The design characteristics of the different stems largely determined the extent of primary stability and fixation pattern. Understanding these different fixation types could help the surgeon to choose the most suitable implant if the fixation conditions in the isthmus are compromised.

Proximal Femoral Replacement in the Management of Acute Periprosthetic Fractures of the Hip: A Competing Risks Survival Analysis

To examine the mortality and implant survivorship of proximal femoral replacement (PFR), revision total hip arthroplasty (REV) and open reduction internal fixation (ORIF) in the treatment of acute periprosthetic fractures of the proximal femur, we retrospectively reviewed 97 consecutive acute periprosthetic proximal femoral fractures from 2000 to 2010. Three groups were defined: PFR (n=21), REV (n=19), and ORIF (n=57). Outcome measures were all-cause mortality, implant failure, and reoperation. Competing Risks survival analysis of overall mortality during the mean 35-month follow-up showed no statistical difference between the three groups (P=0.65; 12 and 60 month mortality for PFR: 37%, 45%; REV: 16%, 46%; ORIF: 14%, 100%). Implant survival was worse for the PFR group (P=0.03, 12 and 60-month implant failure rate for PFR: 5%, 39%; REV: 7%, 7%; ORIF 2%, 2%). We conclude that PFR as compared with REV or ORIF may have worse medium-term implant survival, primarily due to instability and dislocation.

Painful left thigh mass

The patient lived alongside dogs and sheep on a rural Greek farm until he was a teenager. Seventeen years before presentation he emigrated to the United States. The radiographic findings of a lytic bone lesion with cortical destruction, scalloping, and periosteal reaction suggested a primary bone tumor (Fig. 1 in the case presentation). After MRI, chondrosarcoma and sarcoma with necrosis were suspected because of the regions of fluid-like signal intensity within the large soft tissue mass (Fig. 2 in the case presentation). Although echinococcal cyst was also considered, this diagnosis was incorrectly dismissed because the patient had not been on a farm for over 30 years. Therefore, the potential for disease spread and anaphylaxis were not considered prior to biopsy. Percutaneous CT-guided 14-gauge needle biopsy targeted the vastus lateralis to enable needle track resection at surgery. Aspirated fluid and cyst wall fragments were diagnostic of hydatid disease (HD) from Echinococcus granulosus. Radical resection of the soft tissue component with debridement of the femur was performed. Low power histological evaluation showed the hydatid cyst and daughter vesicles with central clear areas that had contained primarily fluid, as well as the perihydatidic adventitia (host response; Fig. 3 in the case presentation). Higher magnification demonstrated the laminated echinococcal membrane and multinucleated giant cells in the adventitia (Fig. 3 inset, in the case presentation). Three years after resection, there was local recurrence with a pathological femoral fracture. Treatment included wide excision requiring proximal femoral replacement with a megaprosthesis total hip arthroplasty. Now, 7 years later, the patient is functioning well without assistive devices and with no recurrence. On radiographs, osseous HD may mimic an aggressive primary or secondary bone tumor, bacterial osteomyelitis, or fibrous dysplasia with coarse trabeculation, sclerosis, bone expansion, erosion, cortical destruction, and osteolysis [1, 2]. MRI may demonstrate characteristic round structures, daughter vesicles, within the mother cyst that are lower signal intensity on T1-weighted images with no enhancement after contrast medium administration, a finding helpful in the diagnosis (Fig. 2 in the case presentation) [1, 2]. The younger daughter vesicles appear darker on T1-weighted images because they contain more pure fluid and fewer protoscoleces than the mother cyst [3]. While the “rim sign,” a thick dark cyst wall on T2-weighted images, is characteristic at other sites [4], it is not as specific a finding in muscle. After contrast medium administration, the perihydatidic layer typically enhances [1] (Fig. 2c in the case presentation). Hydatid disease, which occurs in endemic areas worldwide, has a well-described life cycle [5–7]. Dogs are The case presentation can be found at doi: 10.1007/s00256-013-1634-3. F. A. Sakamoto : C. S. Winalski (*) Imaging Institute, Cleveland Clinic, 9500 Euclid Avenue, A21, Cleveland, OH 44195, USA e-mail: winalsc@ccf.org

Safety aspects in surgical treatment of pathological fractures of the proximal femur – modular endoprosthetic replacement vs. intramedullary nailing

BackgroundPathologic fractures of the femoral intertrochanteric and subtrochanteric region require special consideration in terms of biomechanically stable fixation and durability of the implant. In addition, the type of surgery might also influence patient survival. We conducted this retrospective study to evaluate the safety of modular proximal femur replacement compared to intramedullary nailing with patient survival being the primary and complications the secondary endpoint.MethodsWe retrospectively studied the records of 20 consecutive patients with actual pathologic fracture due to bone metastasis in the intertrochanteric and subtrochanteric part of the femur. The pathologic fractures were stabilized with a locked cephalomedullary nail in 12 patients and treated with en-bloc resection and modular proximal femur replacement in eight patients.ResultsIn the tumor prosthesis group median patient survival was more than twice as high (4.5 months, IQR 2.3 – 16.5) than in the osteosynthesis group (2.0 months, IQR 0.3 – 20.5), but did not reach significance (p = 0.58). Besides, a significantly better preoperative general health status in patients with endoprosthetic reconstruction puts better survival into perspective. Median implant survivorship did not differ between groups with 2.5 (IQR 1.0 – 7.5) months for endoprothesis and 3.0 (IQR 0.3 – 11.0) months for osteosynthesis (p = 0.93). Complication rates were comparable with 25% in each group.ConclusionPatient survival was not influenced by type of surgery or choice of implant. Preoperative general health condition and ambulatory capacity may aid in decision for type of surgery and improve patient safety, respectively.

Massive bone loss

Revision total hip arthroplasty (THA) is projected to increase by 137% from the years 2005 to 2030. Reconstruction of the femur with massive bone loss can be a formidable undertaking. The goals of revision surgery are to create a stable construct, preserve bone and soft tissues, augment deficient host bone, improve function, provide a foundation for future surgery, and create a biomechanically restored hip. Options for treatment of the compromised femur include: resection arthroplasty, allograft prosthetic composite (APC), proximal femoral replacement, cementless fixation with a modular tapered fluted stem, and impaction grafting. The purpose of this article is to review the treatment options along with their associated outcomes in the more severe femoral defects (Paprosky types IIIb and IV) in revision THA.

Proximal Femoral Replacement and Allograft Prosthesis Composite in the Treatment of Periprosthetic Fractures with Significant Proximal Bone Loss

Femoral bone loss due to periprosthetic fracture, a challenging problem in total hip arthroplasty (THA), is increasingly encountered due to a rise in the number of revision THAs performed. Allograft prosthesis composite (APC) and proximal femoral replacement (PFR) are two available options for management of patients with difficult type-B3 Vancouver periprosthetic fractures. The treatment algorithm for patients with these fractures has been extensively studied and is influenced by the age and activity level of the patient. APC is often preferred in young and active patients in an attempt to preserve bone stock while older and less active patients are considered candidates for PFR. In spite of the high rate of overall complications with these two procedures, reported survivorship is acceptable. Treating patients with these complicated fractures is fraught with complications and, even with successful treatment, the outcomes are not as promising as those associated with primary hip replacement. In this paper, we aimed to review available published reports about PFR and APC for treatment of periprosthetic fractures around THAs.

Der Anbindungsschlauch zur Weichteilrekonstruktion nach Megaprothesenimplantation

To restore function and an active range of motion, and stabilize the joint after joint resection. Restoration of a joint capsule following reconstruction of a defect using a proximal humerus and femur prosthesis. Reattachment of tendons and muscles. Acute or chronic infection. Status after cured infection. The attachment tube (Implantcast, Buxtehude, Germany) is attached to the joint capsule (proximal humerus and femur replacement) or directly to the prosthesis (for proximal tibial replacements) using nonresorbable Ethibond® sutures (Johnson & Johnson Medical, Norderstedt, Germany). Bone anchors are used, if the joint capsule has been completely resected. The body of the prosthesis, which has previously been attached to the shaft, is then pulled distally through the tube, and a (bipolar) head or humerus cap is placed on top of it. In the proximal humerus and femur replacement, proximal slitting of the tube may be helpful to reposition the prosthesis under vision. Following repositioning, fixation of the tube is completed ventrally and the slits previously made in the tube are sutured. Fixation of the tube to the prosthesis is carried out either with Ethibond® sutures placed around the tube, or--for a proximal humerus and tibia replacement--it is possible to attach suture material to the prosthesis through eyelets. Further treatment basically depends on the location of the mega-endoprosthesis used. Macroscopically and microscopically, fibroblasts migrate into the tube's mesh, so that attachment of the soft tissue takes place. As of yet, no cases of luxation have occurred when the tube is used in combination with a bipolar head, and with fixed-implant cups the risk of luxation can be reduced using tripolar cup systems. In patients with a proximal tibial replacement, active straightening of the knee joint can be restored in most cases, although some limitation on active extension is still possible depending on the extent of the tumor resection.

Der proximale und komplette Femurersatz

Reconstruction of segmental bone defects of the proximal femur following wide tumor resection or revision arthroplasty. Aggressive benign or primary malignant bone tumors of the proximal femur; destructive metastases; massive segmental bone defects of the proximal femur; periprosthetic fractures. Local infection; very short life expectancy (< 3months); massive deficiency of acetabular bone stock. Anterolateral approach. Exposure and detachment of the iliopsoas and gluteus medius muscle from the proximal femur with a sufficient safety margin to the bone; distal transsection of the vastus lateralis/intermedius and rectus femoris muscle according to the extraosseous tumor extension; distal femur osteotomy al least 3cm beyond the farthest point of tumor extension; in case of total femur replacement, additional lateral arthrotomy of the knee with resection of the ligaments and menisci; reaming of the medullary canal after securing the shaft with a Verbrugge clamp; trial assembly and reduction followed by the definitive implantation of the prosthesis with adjustment of the femoral neck anteversion in 5° increments; soft tissue reconstruction and fixation to an attachment tube covering the prosthesis; in case of total femur replacement, the preparation of the tibia is followed by the coupling of the tibial and femoral components. Infection prophylaxis, 20kg partial weight bearing, continuous passive motion. A total of 20 patients with proximal femur replacement and 2patients with total femur replacement implanted between June 2007 and December 2011 were retrospectively reviewed. Three patients had primary malignant bone tumors, while 19patients underwent resection for metastatic disease. The mean age at surgery was 62.0 ± 18.1years (18-82years). Fifteen patients with a mean follow-up of 20.3 ± 17.2months (4-51months) were studied. Among the 22cases, periprosthetic infection occurred in 3patients (13.6%), dislocation in 2patients (9.1%). Evaluation of the functional outcome in 15patients using the MSTS score by Enneking revealed 3very good (20%), 4good (26.7%), 6fair (40%), and 2poor (13.3%) results.