Introduction and Objective. Bone is a tissue which continually regenerates and also having the ability to heal after injuries however, healing of large defects requires intensive surgical treatment. Bioactive glasses are unique materials that can be utilized in both bone and skin regeneration and repair. They are degradable in physiological fluids and have osteoconductive, osteoinductive and osteostimulative properties. Osteoinductive growth factors such as Bone Morphogenetic Proteins (BMP), Vascular Endothelial Growth Factor (VEGF), Epidermal Growth Factor (EGF), Transforming Growth Factor (TGF) are well known to stimulate new bone formation and regeneration. Unfortunately, the synthesis of these factors is not cost- effective and, the broad application of growth factors is limited by their poor stability in the scaffolds. Instead, it is wise to incorporate osteoinductive nanomaterials such as graphene nanoplatelets into the structures of synthetic scaffolds. In this study, borate-based 13-93B3 bioactive glass scaffolds were prepared by polymer foam replication method and they were coated with graphene-containing poly (ε-caprolactone) layer to support the bone repair and regeneration. Materials and Methods. Effects of graphene concentration (1, 3, 5, 10 wt%) on the healing of rat segmental femur defects were investigated in vivo using male Sprague–Dawley rats. Fabricated porous bioactive glass scaffolds were coated by graphene- containing polycaprolactone solution using dip coating method. The prepared 0, 1, 3, 5 and 10 wt% graphene nanoparticle-containing PCL-coated composite scaffolds were designated as BG, 1G-P-BG, 3G-P-BG, 5G-P-BG and 10G-P-BG, for each group (n: 4) respectively. Histopathological and immunohistochemical (bone morphogenetic protein, BMP-2; smooth muscle actin, SMA and alkaline phosphatase, ALP) examinations were made after 4 and 8 weeks of implantation. Results. Results showed that after 8-weeks of implantation both cartilage and bone formation were observed in all animal groups. After 4 and 8 weeks of implantation the both osteoblast and osteoclast numbers were significantly higher in the group 4 compared to the control group. Bone formation was significant starting from 1 wt% graphene-coated bioactive glass implanted group and highest amount of bone formation was obtained in group containing 10 wt% graphene (p<0.001). Newly formed vessels expressed this marker and increased vascularization was observed in 8- weeks period compared to the 4-weeks period. In addition, an increase in new vessel formation were observed in graphene-coated scaffold implanted groups compared to the control group. While cartilage tissue was observed in control group, bone formation percentages were significant in graphene-coated scaffold implanted groups. Highest amount of bone formation occurred in group 4 (10 % wt G-C). Conclusions. Additionally, the presence of graphene nanoplatelets enhanced the BMP-2, SMA and ALP levels compared to the bare bioactive glass scaffolds. It was concluded that pristine graphene-coated bioactive glass scaffolds improve osteointegration and bone formation in rat femur defect when compared to bare bioglass scaffolds

Aims. Custom-made partial pelvis replacements (PPRs) are increasingly used in the reconstruction of large acetabular defects and have mainly been designed using a triflange approach, requiring extensive soft-tissue dissection. The monoflange design, where primary intramedullary fixation within the ilium combined with a monoflange for rotational stability, was anticipated to overcome this obstacle. The aim of this study was to evaluate the design with regard to functional outcome, complications, and acetabular reconstruction. Methods. Between 2014 and 2023, 79 patients with a mean follow-up of 33 months (SD 22; 9 to 103) were included. Functional outcome was measured using the Harris Hip Score and EuroQol five-dimension questionnaire (EQ-5D). PPR revisions were defined as an endpoint, and subgroups were analyzed to determine risk factors. Results. Implantation was possible in all cases with a 2D centre of rotation deviation of 10 mm (SD 5.8; 1 to 29). PPR revision was necessary in eight (10%) patients. HHS increased significantly from 33 to 72 postoperatively, with a mean increase of 39 points (p < 0.001). Postoperative EQ-5D score was 0.7 (SD 0.3; -0.3 to 1). Risk factor analysis showed significant revision rates for septic indications (p ≤ 0.001) as well as femoral defect size (p = 0.001). Conclusion. Since large acetabular defects are being treated surgically more often, custom-made PPR should be integrated as an option in treatment algorithms. Monoflange PPR, with primary iliac fixation, offers a viable treatment option for Paprosky III defects with promising functional results, while requiring less soft-tissue exposure and allowing immediate full weightbearing. Cite this article: Bone Jt Open 2024;5(8):688–696

Background. Despite promising results have shown by osteogenic cell-based demineralized bone matrix composites, they need to be optimized for grafts that act as structural frameworks in load-bearing defects. The purpose of this experiment is to determine the effect of bone marrow mesenchymal stem cells seeding on partially demineralized laser-perforated structural allografts that have been implanted in critical femoral defects. Materials and Methods. Thirty-two wistar rats were divided into four groups according to the type of structural bone allograft; the first: partially demineralized only (Donly), the second: partially demineralized stem cell seeded (DST), the third: partially demineralized laser-perforated (DLP), and the fourth: partially demineralized laser-perforated and stem cell seeded (DLPST). Trans-cortical holes were achieved in four rows of three holes approximated cylindrical holes 0.5 mm in diameter, with centres 2.5 mm apart. P3 MSCs were used for graft seeding. Histologic and histomorphometric analysis were performed at 12 weeks. Results. DLP grafts had the highest woven bone formation, where most parts of laser pores were completely healed by woven bone. DST and DLPST grafts surfaces had extra vessel-ingrowth-like porosities. Furthermore, in the DLPST grafts, a distinct bone formation at the interfaces was noted. Conclusion. This study indicated that surface changes induced by laser perforation, accelerated angiogenesis induction by MSCs, which resulted in endochondral bone formation at the interface. Despite non-optimal results, stem cells showed a tendency to improve osteochondrogenesis, and the process might have improved, if they could have been supplemented with the proper stipulations

Introduction

what size of defect is optimal for creating an atrophic nonunion animal model has not been well defined. Our aim in this study was to establish a clinically relevant model of atrophic nonunion in rat femur by creation of a bone defect to research fracture healing and nonunion.

The use of impaction bone grafting during revision arthroplasty of the hip in the presence of cortical defects has a high risk of post-operative fracture. Our laboratory study addressed the effect of extramedullary augmentation and length of femoral stem on the initial stability of the prosthesis and the risk of fracture.

Cortical defects in plastic femora were repaired using either surgical mesh without extramedullary augmentation, mesh with a strut graft or mesh with a plate. After bone impaction, standard or long-stem Exeter prostheses were inserted, which were tested by cyclical loading while measuring defect strain and migration of the stem.

Compared with standard stems without extramedullary augmentation, defect strains were 31% lower with longer stems, 43% lower with a plate and 50% lower with a strut graft. Combining extramedullary augmentation with a long stem showed little additional benefit (p = 0.67). The type of repair did not affect the initial stability. Our results support the use of impaction bone grafting and extramedullary augmentation of diaphyseal defects after mesh containment.

A new method of treating large bony defects of the proximal femur is described. The defect is filled with a large vascular-pedicled bone graft from the iliac crest. The graft, being nourished by the deep circumflex iliac vessels, remains viable and therefore induces rapid healing of the bone. This method of bony replacement encourages adequate excision of potentially malignant bone lesions and provides sufficient mechanical support to allow early walking. Six clinical cases are presented to illustrate its application.

Revision total hip arthroplasty (rTHA) in the presence of femoral defects can be technically challenging. Reconstruction with long stems is widely accepted as the standard. However long stems can be difficult to insert and can compromise distal bone stock for future revisions. The aims of this study were to identify whether there was a difference in survival and outcomes following rTHA using a long versus standard or short femoral stem. A comprehensive systematic review was performed according to PRISMA guidelines using the MEDLINE, EMBASE, Chochrane Library and Web of Science databases. Inclusion criteria were (i) adult patients >18 years; (ii) randomised controlled trials, joint registry, or cohort studies; (iii) single or staged rTHA for Paprosky 1–3B femoral defects. Exclusion criteria were (i) mixed reporting without subgroup analysis for revision stem length; (ii) ex-vivo studies. Screening for eligibility and assessment of studies was performed by the authors. Out of 341 records, 9 studies met criteria for analysis (including 1 study utilising joint registry data and 1 randomised controlled trial). Across studies there were 3102 rTHAs performed in 2982 patients with a mean age of 67.4 years and a male: female ratio of 0.93. Revision prostheses were long-stemmed in 1727 cases and short or standard in 1375 cases with a mean follow up of 5 years (range, 0-15 years). On subgroup analysis the use of a long cemented stem compared to a long cementless prosthesis was associated with fewer complications and periprosthetic fracture in older patients. Survivorship was 95% with short stems compared to 84% with long stems at 5 years. Moderate quality evidence suggests that in rTHA with Paprosky type 1-3B femoral defects, the use of a short or standard stem can achieve comparable outcomes to long stems with fewer significant complications and revisions. Using a shorter stem may yield a more straightforward surgical technique and can preserve distal bone stock for future revision

Aims. The aim of this study was to determine the outcome of all primary total hip arthroplasties (THAs) and their subsequent revision procedures in patients aged under 50 years performed at our institution. Methods. All 1,049 primary THAs which were undertaken in 860 patients aged under 50 years between 1988 and 2018 in our tertiary care institution were included. We used cemented implants in both primary and revision surgery. Impaction bone grafting was used in patients with acetabular or femoral bone defects. Kaplan-Meier analyses were used to determine the survival of primary and revision THA with the endpoint of revision for any reason, and of revision for aseptic loosening. Results. The mean age of the patients at the time of the initial THA was 38.6 years (SD 9.3). The mean follow-up of the THA was 8.7 years (2.0 to 31.5). The rate of survival for all primary THAs, acetabular components only, and femoral components only at 20 years’ follow-up with the endpoint of revision for any reason, was 66.7% (95% confidence interval (CI) 60.5 to 72.2), 69.1% (95% CI 63.0 to 74.4), and 83.2% (95% CI 78.1 to 87.3), respectively. A total of 138 revisions were performed. The mean age at the time of revision was 48.2 years (23 to 72). Survival of all subsequent revision procedures, revised acetabular, and revised femoral components at 15 years’ follow-up with the endpoint of revision for any reason was 70.3% (95% CI 56.1 to 80.7), 69.7% (95% CI 54.3 to 80.7), and 76.2% (95% CI 57.8 to 87.4), respectively. A Girdlestone excision arthroplasty was required in six of 860 patients (0.7%). Conclusion. The long-term outcome of cemented primary and subsequent revision THA is promising in these young patients. We showed that our philosophy of using impaction bone grafting in patients with acetabular and femoral defects is a very suitable option when treating young patients. Surgeons should realize that knowledge of the outcome of subsequent revision surgery, which is inevitable in young patients, must be communicated to this group of patients prior to their initial THA. Cite this article: Bone Joint J 2022;104-B(3):368–375

Despite the major advances in osteosynthesis after trauma, there remains a small proportion of patients (<10%) who exhibit delayed healing and/or eventual progression to non-union. While known risk factors exist, e.g. advanced age or diabetes, the exact molecular mechanism underlying the impaired healing is largely unknown and identifying which specific patient will develop healing complications is still not possible in clinical practice. The talk will cover our novel multimodal approaches in small animals, which have the potential to precisely capture and understand biological changes during fracture healing on an individual basis. Via combining emerging omics technologies with our recently developed femur defect loading equipment in mice, we provide a platform to precisely link mechanical and molecular analyses during fracture healing

The ability of the body to constantly maintain metabolism homeostasis while fulling the heightened energy and macromolecule demand is crucial to ensure successful tissue healing outcomes. Studies investigating the local metabolic environment during healing are scarce to date. Here, using Type 2 Diabetes (T2D) as a study model, we investigate the impact of metabolism dysregulation on scaffold-guided large-volume bone regeneration. Our study treated wild-type or T2D rats with 5 mm critical-sized femoral defects with 3D-printed polycaprolactone (PCL) scaffolds with 70% porosity. Metabolomics was leveraged for a holistic view of metabolism alteration as healing progress and correlated to regenerated bone tissue volume and quality assessed using micro-computed tomography (µ-CT), histology, and immunohistology. Semi-targeted metabolomics analysis indicated dysregulation in the glycolysis and TCA cycle – the main energy production pathways, in T2D compared to healthy animals. The abundance of metabolites substrates, i.e., amino acids – for protein/ extracellular matrix synthesis was also affected in T2D. Tissue-level metabolites observations aligned with morphological observation with less newly formed bone observed in T2D than wild-type rats. This study enlightens the metabolism landscape during scaffold-guided large-volume bone regeneration in wild-type vs. T2D to further guide the personalization of the scaffold to drive successful regeneration

Bone defects require implantable graft substitutes, especially porous and biodegradable biomaterial for tissue regeneration. The aim of this study was to fabricate and assess a 3D-printed biodegradable hydroxyapatite/calcium carbonate scaffold for bone regeneration. Materials and methods:. A 3D-printed biodegradable biomaterial containing calcium phosphate and aragonite (calcium carbonate) was fabricated using a Bioplotter. The physicochemical properties of the material were characterised. The materials were assessed in vitro for cytotoxicity and ostegenic potential and in vivo in rat intercondylar Φ3mm bone defect model for 3 months and Φ5mm of mini pig femoral bone defects for 6 months. The results showed that the materials contained hydroxyapatite and calcium carbonate, with the compression strength of 2.49± 0.2 MPa, pore size of 300.00 ± 41mm, and porosity of 40.±3%. The hydroxyapatite/aragonite was not cytotoxic and it promoted osteogenic differentiation of human umbilical cord matrix mesenchymal stem cells in vitro. After implantation, the bone defects were healed in the treatment group whereas the defect of controlled group with gelatin sponge implantation remained non-union. hydroxyapatite/aragonite fully integrated with host bone tissue and bridged the defects in 2 months, and significant biodegradation was followed by host new bone formation. After implantation into Φ5mm femoral defects in mini pigs hydroxyapatite/aragonite were completed degraded in 6 months and fully replaced by host bone formation, which matched the healing and degradation of porcine allogenic bone graft. In conclusion, hydroxyapatite/aragonite is a suitable new scaffold for bone regeneration. The calcium carbonate in the materials may have played an important role in osteogenesis and material biodegradation

Femoroacetabular impingement is a prearthritic deformity frequently associated with early chondral damage. Several techniques exist for restoring larger cartilage defects. While AMIC proved to be an effective treatment in knee and ankle, there are only short-term data available in hip. This study aimed to investigate the mid-term clinical outcome of patients with chondral lesions treated by AMIC and evaluate the quality of repair tissue via MRI. This retrospective, single center study includes 18 patients undergoing surgical hip dislocation for FAI between 2013 and 2016. Inclusion criteria were: cam or pincer-type FAI, femoral or acetabular chondral lesions > 1 cm. 2. , (IRCS III-IV). Due to exclusion criteria and loss-to-follow-up 9 patients (10 hips) could be included. Patient reported outcome measures included Oxford Hip Score (OHS) & Core Outcome Measure Index (COMI)). MRIs were evaluated using the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score. None of the patients underwent revision surgery except screw removals from the greater trochanter. Followup data indicate a satisfactory to good hip function at 5 years: PROMS improved from pre- to postop at 5 years: OHS from 38.1 to 43.4, COMI from to 1.8 and UCLA from 4 to 8.1 respectively. MOCART score was 67.5 postoperatively. Subgrouping showed slightly better results for acetabular defects (Ø 69.4) compared femoral defects (Ø 60). Based on the reported mid-term results, we consider AMIC as a valuable treatment option for larger chondral defects of the hip

Although bone morphogenetic protein 2 (BMP-2) has been FDA-approved for spinal fusion for decades, its disadvantages of promoting osteoclast-based bone resorption and suboptimal carrier (absorbable collagen sponge) leading to premature release of the protein limit its clinical applications. Our recent study showed an excellent effect on bone regeneration when BMP-2 and zoledronic acid (ZA) were co-delivered based on a calcium sulphate/hydroxyapatite (CaS/HA) scaffold in a rat critical-size femoral defect model. Therefore, the aim of this study was to evaluate whether local application of BMP-2 and ZA released from a CaS/HA scaffold is favorable for spinal fusion. We hypothesized that CaS/HA mediated controlled co-delivery of rhBMP-2 and ZA could show an improved effect in spinal fusion over BMP-2 alone. 120, 8-week-old male Wistar rats (protocol no. 25-5131/474/38) were randomly divided into six groups in this study (CaS/HA, CaS/HA + BMP-2, CaS/HA + systemic ZA, CaS/HA + local ZA, CaS/HA + BMP-2 + systemic ZA, CaS/HA + BMP-2 + local ZA). A posterolateral spinal fusion at L4 to L5 was performed bilaterally by implanting group-dependent scaffolds. At 3 weeks and 6 weeks, 10 animals per group were euthanized for µCT, histological staining, or mechanical testing. µCT and histological results showed that the CaS/HA + BMP-2 + local ZA group significantly promoted bone regeneration than other treated groups. Biomechanical testing showed breaking force in CaS/HA + BMP + local ZA group was significantly higher than other groups at 6 weeks. In conclusion, the CaS/HA-based biomaterial functionalized with bioactive molecules rhBMP-2 and ZA enhanced bone formation and concomitant spinal fusion outcome. Acknowledgements: Many thanks to Ulrike Heide, Anna-Maria Placht (assistance with surgeries) as well as Suzanne Manthey & Annett Wenke (histology)

Aims. Revision total hip arthroplasty in patients with Vancouver type B3 fractures with Paprosky type IIIA, IIIB, and IV femoral defects are difficult to treat. One option for Paprovsky type IIIB and IV defects involves modular cementless, tapered, revision femoral components in conjunction with distal interlocking screws. The aim of this study was to analyze the rate of reoperations and complications and union of the fracture, subsidence of the stem, mortality, and the clinical outcomes in these patients. Methods. A total of 46 femoral components in patients with Vancouver B3 fractures (23 with Paprosky type IIIA, 19 with type IIIB, and four with type IV defects) in 46 patients were revised with a transfemoral approach using a modular, tapered, cementless revision Revitan curved femoral component with distal cone-in-cone fixation and prospectively followed for a mean of 48.8 months (SD 23.9; 24 to 112). The mean age of the patients was 80.4 years (66 to 100). Additional distal interlocking was also used in 23 fractures in which distal cone-in-cone fixation in the isthmus was < 3 cm. Results. One patient (2.2%) died during the first postoperative year. After six months, 43 patients (93.5%) had osseous, and three had fibrous consolidation of the fracture and the bony flap, 42 (91.3%) had bony ingrowth and four had stable fibrous fixation of the stem. No patient had radiolucency around the interlocking screws and no screw broke. One patient had non-progressive subsidence and two had a dislocation. The mean Harris Hip Score increased from of 57.8 points (SD 7.9) three months postoperatively to 76.1 points (SD 10.7) 24 months postoperatively. Conclusion. The 2° tapered, fluted revision femoral component with distal cone-in-cone-fixation, combined with additional distal interlocking in patients with bony deficiency at the isthmus, led to reproducibly good results in patients with a Vancouver B3 fracture and Paprosky type IIIA, IIIB, and IV defects with regard to union of the fracture, subsidence or loosening of the stem, and clinical outcomes. Cite this article: Bone Joint J 2024;106-B(4):344–351

Principles of bone preservation and restoration of biomechanical alignment should be followed during revision total hip arthroplasty (THA). Where possible, conservative femoral revision techniques and even reconstructive de-escalation involving using primary stems should be considered. This study aims to investigate the outcome of patients who have undergone conservative femoral revision THA in our Institution. We retrospectively identified patients from our Institution's revision arthroplasty database who had cemented, or un-cemented primary stems implanted during revision THA of a previous stemmed femoral implant. Our primary outcome measure was all-cause re-revision THA with a secondary outcome measure of improvement in Oxford hip score (OHS). Radiographic evidence of stem loosening and post-op complications were recorded. Between 02/12/2014 to 12/12/2019, there were 226 patients identified with a mean follow up of 2 years (1–5 years). The majority of cases were represented by Paprosky type 1 (63%) and type 2 (25%) femoral defects. There were 45 patients (20%) who underwent impaction bone grafting (IBG) and 43 patients (19%) who had a cement in cement (CinC) femoral revision and cemented primary stem in 137 (60%), 1 uncemented stem with no IBG or CinC revision. Kaplan Meier survival for all-cause re-revision THA was 93.7% (95% CI: 88.3 – 100) at 3 years. The reasons for re-revision included 4 periprosthetic fractures, 4 dislocations, 1 deep infection, 1 loosening of femoral component and 1 loosening of acetabular component. Pre- and post-operative OHS scores were available in 137 hips (60%) with a mean improvement of 13. Radiographic review revealed 7% of cases with evidence of loosening in 1 or more Gruen zones. Our early results support the use of conservative femoral revision THA techniques where appropriate, with low complication and re-revision rates. Revisions using primary femoral components, where appropriate, should be considered in surgical planning to avoid unnecessary reconstructive escalation

Background. We have reported an injectable L-pNIPAM-co-DMAc hydrogel with hydroxyaptite nanoparticles (HAPna) which promotes mesenchymal stem cell (MSC) differentiation to bone cells without the need for growth factors. This hydrogel could potentially be used as an osteogenic and osteoconductive bone filler of spinal cages to improve vertebral body fusion. Here we investigated the biocompatibility and efficacy of the hydrogel in vivo using a proof of concept femur defect model. Methods. Rat sub-cut analysis was performed to investigate safety in vivo. A rat femur defect model was performed to evaluate efficacy. Four groups were investigated: sham operated controls; acellular L-pNIPAM-co-DMAc hydrogel; acellular L-pNIPAM-co-DMAc hydrogel with HAPna; L-pNIPAM-co-DMAc hydrogel with rat MSCs and HAPna. Following 4 weeks, defect site and organs were histologically examined to determine integration, repair and inflammatory response, as well as Micro-CT to assess mineralisation. Results. No inflammatory reactions or toxicity were seen in any animal. Enhanced bone healing was observed in aged exbreeder female rats where hydrogel was injected with increased deposition of collagen type I. Integration of the hydrogel with surrounding bone was observed without the need for delivered MSCs; native cell infiltration was also seen and bone formation was observed within all hydrogel systems investigated. Conclusion. This novel hydrogel is biocompatible, facilitates migration of cells, promotes increased bone formation and integrates with surrounding bone. This system could be injected to fill spaces within and surrounding spinal cages to aid in cage fixation and spinal fusion without the need for harvesting of bone autografts, thus reducing operative risk and surgical cost. Conflicts of Interest: None. Source of Funding: BMRC, MERI Sheffield Hallam University

An ex vivo biomechanical test model for evaluating a novel bone adhesive has been developed. However, at day 1 in the in vivo pilot, high blood flow forced the study to halt until the solution presented here was developed. The profuse bleeding after bone core removal affected the bond strength and was reflected in the lower mean peak value 1.53N. After considering several options, we were successful in sealing the source of blood flow by pressing adhesive into place after bone core removal. After the initial adhesive had cured additional adhesive was used to secure the bone core in place. The animals were sacrificed after 24 h and a tensile test was undertaken on the bone core to failure. The ex vivo study produced mean peak tensile loads of 7.63N SD 2.39N (n=8, 4 rats 8 femurs). Whilst the mean peak tensile loads in the day 1 in vivo pilot were significantly lower 1.53N SD1.57 (n=8, 6 rats 8 femurs − 4 used for other tests). The subsequent layered adhesive bone cores showed a mean peak tensile force of 6.79N SD =3.13 (n=8, 4 rats 8 femurs). 7/8 failed at the bone to glue interface. This is the first successful demonstration of bonding bone in vivo for this class of adhesives. The development of a double adhesive method of fixing a bone core in the distal femur enabled mean peak tensile forces to be achieved in vivo at 24 hours that were comparable with the ex vivo results previously demonstrated. This method supports application in further animal series and over longer time scales. Biomaterials researchers that intend to use gel or paste like preparations in distal femur defects in the rat should be aware of the risks of biomaterial displacement by local blood flow

Aims. We have evaluated the survivorship, outcomes, and failures of an interlocking, reconstruction-mode stem-sideplate implant used to preserve the native hip joint and achieve proximal fixation when there is little residual femur during large endoprosthetic reconstruction of the distal femur. Methods. A total of 14 patients underwent primary or revision reconstruction of a large femoral defect with a short remaining proximal femur using an interlocking, reconstruction-mode stem-sideplate for fixation after oncological distal femoral and diaphyseal resections. The implant was attached to a standard endoprosthetic reconstruction system. The implant was attached to a standard endoprosthetic reconstruction system. None of the femoral revisions were amenable to standard cemented or uncemented stem fixation. Patient and disease characteristics, surgical history, final ambulatory status. ,. and Musculoskeletal Tumor Society (MSTS) score were recorded. The percentage of proximal femur remaining was calculated from follow-up radiographs. Results. All 14 at-risk native hip joints were preserved at a mean final follow-up of 6.0 years (SD 3.7), despite a short residual femur, often after proximal osteotomies through the lesser trochanter. Overall, 13 of 14 stems had long-term successful fixation. Eight patients required no reoperation. Three patients required reoperation due to implant-related issues, and three patients required reoperation for wound healing problems or infection. There were no dislocations or fractures. At final follow-up the mean MSTS score was 24.9 (SD 4.1). Nine patients required no ambulation aids, and only one had a Trendelenburg gait. Conclusion. This interlocking, reconstruction-mode stem-sideplate reliably preserves native hip joint anatomy and function after large femoral resection with a short remaining proximal femur, both in the primary and revision setting. This is particularly important for preventing or delaying total femoral arthroplasty in young patients after oncological reconstruction. Hip abductor strength and function could be maintained by this method, and the risk of dislocation eliminated. The success of this technique in this modest series should be verified in a larger collaborative study and will be of interest to revision surgeons and oncologists. Cite this article: Bone Joint J 2021;103-B(2):398–404

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.

Staged revision arthroplasty for the periprosthetic hip infection is the accepted mode of treatment. Unfortunately, the first stage revision compromises the patient’s function secondary to inability to weight-bear. Pros-theses coated with antibiotic-loaded cement have been adapted to improve function but have failed in larger femoral defects. This implant and technique described improves patient mobility and decreases morbidity as compared to conventional techniques. The purpose of this study was to find an implant to accommodate most femoral defects and to be readily available for managing periprosthetic hip infections. A prospective study was performed comparing the PROSTALAC(DePuy, IN) implant (Group I) to a Solution(DePuy, IN) implant (Group II) covered in antibiotics for management of the first stage. All patients had a confirmed pyogenic gram positive or gram negative infection. Fifty-two patients were compared with each group being matched by their femoral defect type (Paprosky: Type I and II: 24, Type III:20, Type IV: 8). Follow-up was for a minimum of thirty-six months. All patients were encouraged to weight bear as tolerated. One recurrence of infection occurred after a second stage revision in Group I. Cost of the implant averaged $700 cheaper in Group II. More significant was the fact that the average length of hospital stay was decreased in Group II by seven days and forty-seven days for the Type III and Type IV femurs respectively. All patients in Group I received a second stage revision. Five of the Group II patients refused a second stage revision secondary to their satisfactory function and had better post-op function. An alternative treatment for staged periprosthetic hip infections is proposed which can decrease hospital stay, improve function, and allow routine implant use for its implementation

The purpose of this prospective study was to evaluate the long-term clinical and radiological outcomes of revision of the femoral component of a total hip replacement using impaction bone grafting. Femoral revision with an impacted allograft was performed on 29 patients (31 hips). In all, 21 hips (68%) had grade III or IV femoral defects according to the Endo-Klinik classification. A total of 11 patients (12 hips) died before the ten-year follow-up period. Of the remaining patients, 18 patients (19 hips) were followed for 10 to 15 years; three further patients died during this time. None of the 31 stems underwent further revision of their stem. However, four stems showed extensive subsidence (> 15 mm). One of these patients had a femoral fracture that required fixation. Three other patients had a femoral fracture, two of which required fixation and the other was treated conservatively. Patients with a femoral fracture and/or severe subsidence had significantly more grade IV defects (six of seven hips; p = 0.004). One patient needed a closed reduction for dislocation. Impaction allografting in revision hip surgery gives good long-term results for femora with grades I, II and III Endo-Klinik-classified defects. Extensive subsidence and femoral fractures were seen mainly in patients with grade IV damaged femora

Revision hip surgery is about simplification. As such, a single revision stem makes sense. The most important advantage of Tapered Conical Revision (TCR) stem is versatility - managing ALL levels of femoral bone loss (present before revision or created during revision). The surgeon and team quickly gain familiarity with the techniques and instruments for preparation and implantation and subsequently master its use for a variety of situations. This ability to use the stem in a variety of bone loss situations eliminates intraoperative shuffle (changes in the surgical plan resulting in more instruments being opened), as bone loss can be significantly underestimated preoperatively or may change intraoperatively. Furthermore, distal fixation can be obtained simply and reliably. Paprosky 1 femoral defects can be treated with a primary-type stem for the most part. All other femoral defects can be treated with a TCR stem. Fully porous coated stems also work for many revisions but why have two different revision stem choices available when the TCR stems work for ALL defects?. TCR stems can be modular or monolithic but there are common keys to success. First and foremost, proper exposure is essential to assess bone defects and to safely prepare the femur. An extended osteotomy is often useful. Reaming distally to prepare a cone for fixation of the conical stem is a critical requirement to prevent subsidence (true for all revision stems). Restoration of hip mechanics (offset, leg length and stability) is fundamental to the clinical result. TCR stems have instrumentation and techniques that ensure this happens, since all this occurs AFTER distal stability is achieved. Modular TCR versions have some advantages. The proximal body size and length can be adjusted AFTER stem insertion if the stem goes deeper than the trial. Any proximal/distal bone size mismatch can be accommodated. If the surgeon believes that proximal bone ingrowth is important to facilitate proximal bone remodeling, modular TCR stems can more easily accomplish this. Further, proximal bone contact and osseointegration will protect the modular junction from stress and possible risk of fracture. Monolithic TCR versions also have some advantages. Modular junction mechanical integrity cannot accommodate smaller bone sizes. Shorter stem lengths are not available in modular versions, and shorter TCR stems are an option in many revision cases. The possibility of modular junction corrosion is eliminated and fracture of the stem at that junction, of course, is not possible. The monolithic stem option is less expensive as well. Consider Modular TCR stems in your learning curve, if you feel proximal bone osseointegration is important and if proximal/distal size mismatch is present. Consider Monolithic TCR stems after your learning curve to reduce cost, when a short stem works, and if a small stem is needed. Both Modular and Monolithic stems can be used for ALL cases with equal quality of result

Objectives. Recent studies have shown that modulating inflammation-related lipid signalling after a bone fracture can accelerate healing in animal models. Specifically, decreasing 5-lipoxygenase (5-LO) activity during fracture healing increases cyclooxygenase-2 (COX-2) expression in the fracture callus, accelerates chondrogenesis and decreases healing time. In this study, we test the hypothesis that 5-LO inhibition will increase direct osteogenesis. Methods. Bilateral, unicortical femoral defects were used in rats to measure the effects of local 5-LO inhibition on direct osteogenesis. The defect sites were filled with a polycaprolactone (PCL) scaffold containing 5-LO inhibitor (A-79175) at three dose levels, scaffold with drug carrier, or scaffold only. Drug release was assessed in vitro. Osteogenesis was assessed by micro-CT and histology at two endpoints of ten and 30 days. Results. Using micro-CT, we found that A-79175, a 5-LO inhibitor, increased bone formation in an apparent dose-related manner. Conclusions. These results indicate that 5-LO inhibition could be used therapeutically to enhance treatments that require the direct formation of bone

Modern modular revision stems employ tapered conical (TCR) distal stems designed for immediate axial and rotational stability with subsequent osseo-integration of the stem. Modular proximal segments allow the surgeon to achieve bone contact proximally with eventual ingrowth that protects the modular junction. The independent sizing of the proximal body and distal stem allows for each portion to obtain intimate bony contact and gives the surgeon the ability precisely control the femoral head center of rotation, offset, version, leg length, and overall stability. The most important advantage of modular revision stems is versatility - the ability to manage ALL levels of femoral bone loss (present before revision or created during revision). Used routinely, this allows the surgeon to quickly gain familiarity with the techniques and instruments for preparation and implantation and subsequently master the use for all variety of situations. This also allows the operating room staff to become comfortable with the instrumentation and components. Additionally, the ability to use the stem in all bone loss situations eliminates intra-operative shuffle (changes in the surgical plan resulting in more instruments being opened), as bone loss can be significantly under-estimated pre-operatively or may change intra-operatively. Furthermore, distal fixation can be obtained simply and reliably. Paprosky 1 femoral defects can be treated with a primary-type stem for the most part. All other femoral defects can be treated with a TCR stem. Fully porous coated stems also work for many revisions but why have two different revision stem choices available when the TCR stems work for ALL defects?. The most critical advantage is the ability to separate completely the critical task of fixation from other important tasks of restoring offset, leg length, and stability. Once fixation is secured, the surgeon can concentrate on hip stability and on optimization of hip mechanics (leg length and offset). The ability to do this allows the surgeon to maximise patient functionality post-operatively. Modular tapered stems have TWO specific advantages over monolithic stems in this important surgical task. The proximal body size and length can be adjusted AFTER stem insertion if the stem goes deeper than the trial. Further, proximal/distal bone size mismatch can be accommodated. The surgeon can control the diameter of the proximal body to ensure proper bony apposition independent of distal fitting needs. If the surgeon believes that proximal bone ingrowth is important to facilitate proximal bone remodeling, modular TCR stems can more easily accomplish this. The most under-appreciated advantage is the straightforward instrumentation system that makes the operation easier for the staff and the surgeon, while enhancing the operating room efficiency and reducing cost. Also, although the implant itself may result in more cost, most modular systems allow for a decrease in inventory requirements, which make up the cost differential. One theoretical disadvantage of modular revision stems is modular junction fracture, which can happen if the junction itself is not protected by bone. Ensuring proximal bone support can minimise this problem. Once porous ingrowth occurs proximally, the risk of junction fracture is eliminated. Even NON-modular stems fracture when proximal bone support is missing. Another theoretical issue is modular junction corrosion but this not a clinical one, since both components are titanium. One can also fail to connect properly the two parts during surgery

Despite the increasing availability of bone grafting materials, the regeneration of large bone defects remains a challenge. Especially infection prevention while fostering regeneration is a crucial issue. Therefore, loading of grafting material with antibiotics for direct delivery to the site of need is desired. This study evaluates the concept of local delivery using in vitro and in vivo investigations. We aim at verifying safety and reliability of a perioperative enrichment procedure of demineralized bone matrix (DBM) with gentamicin. DBM (DBMputty, DIZG, Germany) was mixed with antibiotic using a syringe with an integrated mixing propeller (Medmix Systems, Switzerland). Gentamicin, as powder or solution, was mixed with DBM at different concentrations (25 −100 mg/g DBM), release and cytotoxicity was analyzed. For in vivo analysis, sterile drill hole defects (diameter: 6 mm, depth: 15 mm) were created in diaphyseal and metaphyseal bones of sheep (Pobloth et al. 2016). Defects (6 – 8 per group and time point) were filled with DBM or DBM enriched with gentamicin (50 mg/g DBM) or left untreated. After three and nine weeks, defect regeneration was analyzed by µCT and histology. The release experiments revealed a burst release of gentamicin from DBM independent of the used amount, the sampling strategy, or the formulation (powder or solution). Gentamicin was almost completely released after three days in all set-ups. Eluates showed an antimicrobial activity against S. aureus over at least three days. Eluates had no negative effect on viability and alkaline phosphatase activity of osteoblast-like cells (partially published Bormann et al. 2014). µCT and histology of the drill hole defects revealed a reduced bone formation with gentamicin loaded DBM. After nine weeks significantly less mineralized tissue was detectable in metaphyseal defects of the gentamicin group. Histological evaluation revealed new bone formation starting at the edges of the drill holes and growing into the center over time. The amount of DBM decreased over time due to the active removal by osteoclasts while osteoblasts formed new bone. Using this mixing procedure, loading of DBM was fast, reliable and possible during surgical setting. In vitro experiments revealed a burst and almost complete release after three days, antimicrobial activity and good biocompatibility of the eluates. Gentamicin/DBM concentration was in the range of clinically used antibiotic-loaded-cement for prophylaxis and treatment in joint replacement (Jiranek et al. 2006). The delayed healing seen in vivo was unexpected due to the good biocompatibility found in vitro. A reduced healing was also seen in spinal fusion where DBM was mixed with vancomycin (Shields et al. 2017), whereas DBM with gentamicin or DBM/bioactive glass with tobramycin had no negative effect on osteoinductivity or femur defect healing, respectively (Lewis et al. 2010, Shields et al. 2016). In conclusion, loading of DBM with gentamicin showed a proper antibiotic delivery over several days, covering the critical phase shortly after surgery. Due to the faster and complete release of the antibiotic compared to antibiotic loaded cement, the amount of antibiotic should be much lower in the DBM compared to cement

The potential of piezoelectric biomaterials for bone tissue engineering is demonstrated. This work proves that the use of piezoelectric poly(vinylidene fluoride) (PVDF), able to provide electrical stimuli upon mechanical solicitation to the growing bone cells, enhances the bone regeneration in vivo. Poled and non-poled PVDF films, with and without macroscopic piezoelectric response, respectively and randomly oriented piezoelectric electrospun fiber mats have been used as substitutes for bone to test their osteogenic properties in Wistar rats by analyzing new bone formation in 3 mm bilateral femur defects in vivo. After 4 weeks, the qualification of the regenerated bone was performed according the H&E staining. Defect implanted with poled PVDF films demonstrated significantly more defect closure and bone remodeling, showing the large potential of piezoelectric biomaterials for bone repair, as well as for other electromechanical responsive tissues such as muscle and tendon

Bone has a remarkable capacity to heal. However, in some instances the amount of bone which is needed to heal exceeds its healing capacity. Due to reported issues with current treatments there is continued research into alternative approaches with a view to producing an off the shelf alternative to the gold standard autologous bone transplants. The current investigated the use of a chitosan/hydroxyapatite scaffold, which was used to covalently bone morphogenetic protein and vascular endothelial growth factor using a UV crosslinking process. Results indicate that the incorporation of hydroxyapatite increased the mechanical properties of the scaffold compared to chitosan alone. Furthermore, crosslinking was confirmed using swelling studies and FTIR analysis. Elisa indicated that physiological doses of BMP were released after 10 days while in vitro testing did not indicate a cytotoxic response to the scaffold. In vivo testing in a rat femoral defect model indicated the efficacy of the treatment with scaffolds containing BMP and VEGF in combination resulting in more bone in the defect compared to the scaffold alone 8 weeks post-surgery

We determined the midterm survival, incidence of peri-prosthetic fracture and the enhancement of the width of the femur when combining struts and impacted bone allografts in 24 patients (25 hips) with severe femoral bone loss who underwent revision hip surgery. The pre-operative diagnosis was aseptic loosening in 16 hips, second-stage reconstruction in seven, peri-prosthetic fracture in one and stem fracture in one hip. A total of 14 hips presented with an Endoklinik grade 4 defect and 11 hips a grade 3 defect. The mean pre-operative Merle D’Aubigné and Postel score was 5.5 points (1 to 8). The survivorship was 96% (95% confidence interval 72 to 98) at a mean of 54.5 months (36 to 109). The mean functional score was 17.3 points (16 to 18). One patient in which the strut did not completely bypass the femoral defect was further revised using a long cemented stem due to peri-prosthetic fracture at six months post-operatively. The mean subsidence of the stem was 1.6 mm (1 to 3). There was no evidence of osteolysis, resorption or radiolucencies during follow-up in any hip. Femoral width was enhanced by a mean of 41% (19% to 82%). A total of 24 hips had partial or complete bridging of the strut allografts. This combined biological method was associated with a favourable survivorship, a low incidence of peri-prosthetic fracture and enhancement of the width of the femur in revision total hip replacement in patients with severe proximal femoral bone loss

Purpose. In revision hip surgery, Type IIIB femurs have presented the greatest historical challenge to achieving stable fixation and osseous integration. This study evaluated the intermediate term outcome of a modular, tapered, distal fixation revision femoral component used in a consecutive revision hip series with special attention to its performance in the defective Type IIIB femur. Methods. Between February 2002 and January 2005, 51 consecutive revision hip arthroplasties were performed using modular, tapered, distal fixation femoral components. The femoral defects at the time of revision surgery were classified using a system previously described by Paprosky. The most recent radiographs were reviewed and clinic notes examined to assess femoral component stability. Results. At a minimum of 4.2 years and a mean of 5.8 years follow-up, 2 patients were lost to follow-up. Revision cases classified by the Paprosky femoral defect classification system included 14 Type IIIB hips (28%). All hips reviewed (100%) had radiographic evidence of bony ingrowth. No stem migrated more than 2mm. There were no failures at the modular junction and no component disassociation.??Conclusion: A modular, tapered distal fixation femoral component had a 100% survival rate at mean 5.8 year follow-up after revision surgery. All femoral components showed successful osseous-integration. The ability with modularity to independently place the diaphyseal segment of a femoral component in the best remaining femoral host bone may have provided the greatest opportunity for osseous-integration. In this consecutive revision hip series there was no instance of modular junction fracture or component related failure in cases with minimal or no proximal bone support

Introduction. Within the reconstruction of unicondylar femoral bone defects with morselized bone grafts in revision total knee arthroplasty (TKA), a stem extension appears to be critical to obtain adequate mechanical stability. Whether the stability is still secured by this reconstruction technique in bicondylar defects has not been assessed. Long, rigid stem extensions have been advocated to maximize the stability in revision TKAs. The disadvantage of relatively stiff stem extensions is that bone resorption is promoted due to stress shielding. Therefore, we developed a relatively thin intramedullary stem which allowed for axial sliding movements of the articulating part relative to the intramedullary stem. The hypothesis behind the design is that compressive contact forces are directly transmitted to the distal femoral bone, whereas adequate stability is provided by the sliding intramedullary stem. A prototype was made of this new knee revision design and applied to the reconstruction of uncontained bicondylar femoral bone defects. Materials and Methods. Five synthetic distal femora with a bicondylar defect were reconstructed with impacted bone grafting (IBG) and this new knee revision design. A custom-made screw connection between the stem and the intercondylar box was designed to lock or initiate the sliding mechanism, another screw (dis)connected the stem. A cyclically axial load of 500 N was applied to the prosthetic condyles to assess the stability of the reconstruction. Radiostereometry was used to determine the migrations of the femoral component with a rigidly connected stem, a sliding stem and no stem extension. Results. We found a stable reconstruction of the bicondylar femoral defects with IBG in case of a rigidly connected stem. After disconnecting the stem, the femoral component showed substantially more migrations. With a sliding stem rotational migrations were similar to those of a rigidly connected stem. However, the sliding stem allowed proximal migration of the condylar component, thereby compressing the IBG. Discussion. A stable reconstruction of uncontained bicondylar femoral defects could be created with IBG and a TKA with a thin stem extension. It appeared that the presence of a functional stem extension was important for the stability of the bicondylar reconstruction. In an effort to reduce stress shielding, we developed a sliding stem mechanism. This sliding stem provided adequate stability, while compressive contact forces are still transmitted to the distal femoral bone. Clinical studies have to confirm that our sliding stem mechanism leads to long term bone maintenance after revision TKAs

Objectives. The purpose of this study was to refine an accepted contaminated rat femur defect model to result in an infection rate of approximately 50%. This threshold will allow examination of treatments aimed at reducing infection in open fractures with less risk of type II error. Methods . Defects were created in the stablised femurs of anaethetised rats, contaminated with Staphylococcus aureus and then debrided and irrigated six hours later. After 14 days, the bone and implants were harvested for separate microbiological analysis. This basic model was developed in several studies by varying the quantity of bacterial inoculation, introducing various doses of systemic antibiotics with and without local antibiotics. Results . The bacterial inoculation associated with a 50% infection rate was established as 1 × 10. 2. colony forming units (CFU). With an initial bacterial inoculum of 1 × 10. 5. CFU, the dose of systemic antibiotics associated with 50% infection was 5 mg/Kg of cafazolin injected sub-cutaneously every 12 hours, starting at the time of the first debridment and continuing for 72 hours (seven doses). The systemic dose of cafazolin was lowered to 2 mg/Kg when antibiotic polymethyl methacrylate beads were used concurrently with the same amount of bacterial inoculation. Conclusion. This model of open fracture infection has been further refined with potential for local and systemic antibiotics. This is a versatile model and with the concepts presented herein, it can be modified to evaluate various emerging therapies and concepts for open fractures. Cite this article: Bone Joint Res 2014;3:187–92

We describe the technique and results of medial submuscular plating of the femur in paediatric patients and discuss its indications and limitations. Specifically, the technique is used as part of a plate-after-lengthening strategy, where the period of external fixation is reduced and the plate introduced by avoiding direct contact with the lateral entry wounds of the external fixator pins. The technique emphasises that vastus medialis is interposed between the plate and the vascular structures. . A total of 16 patients (11 male and five female, mean age 9.6 years (5 to 17)), had medial submuscular plating of the femur. All underwent distraction osteogenesis of the femur with a mean lengthening of 4.99 cm (3.2 to 12) prior to plating. All patients achieved consolidation of the regenerate without deformity. The mean follow-up was 10.5 months (7 to 15) after plating for those with plates still in situ, and 16.3 months (1 to 39) for those who subsequently had their plates removed. None developed a deep infection. In two patients a proximal screw fractured without loss of alignment; one patient sustained a traumatic fracture six months after removal of the plate. . Placing the plate on the medial side is advantageous when the external fixator is present on the lateral side, and is biomechanically optimal in the presence of a femoral defect. We conclude that medial femoral submuscular plating is a useful technique for specific indications and can be performed safely with a prior understanding of the regional anatomy. Cite this article: Bone Joint J 2014;96-B:137–42

Stems provide short- and long-term stability to the femoral and tibial components. Poorer epiphyseal and metaphyseal bone quality will require sharing or offloading the femoral and tibial component interfaces with a stem. One needs to use stem technique most appropriate for each individual case because of variable anatomy and bone loss situations. The conflict with trying to obtain stability via the stem is that most stems are cylindrical but femoral and tibial metaphyseal/diaphyseal areas are conical in shape. Viable stem options include fully cemented short and long stems, uncemented long stems, offset uncemented stems, and a hybrid application of a cemented proximal end of longer uncemented diaphyseal engaging stems. Stems are not without their risk. The more the load is transferred to the cortex, the greater the risk of proximal interface stress shielding. A long uncemented stem has similar stress shielding as a short cemented stem. Long diaphyseal engaging stems that are cemented or uncemented have the potential to have end of stem pain, especially if more diaphyseal reaming is done to obtain greater cortical contact. A conical shaped long stem can provide more stability than a long cylindrical stem and avoid diaphyseal reaming. Use of long stems may create difficulty in placement of the tibial and femoral components in an optimal position. If the femoral or tibial components do not allow an offset stem insertion, using a long offset stem or short cemented stem is preferred. The amount of metaphyseal bone loss will drive the choice of stem used. Short cemented stems will not have good stability in poor metaphyseal bone without getting the cement out to the cortex. Long cemented stems provide satisfactory survivorship, however, most surgeons avoid cementing long stems due to the difficulty of removal, if a subsequent revision is required. If the metaphyseal bone is excellent, use of a short cemented stem or long uncemented stem can be expected to have good results. Long fully uncemented stems must have independent stability to be effective, or should be proximally cemented as a hybrid technique. Cases with AOI type IIb and III tibial and femoral defects are best managed with use of metaphyseal cones with short cemented stems or long hybrid straight or offset stems. Some studies also suggest that if the cone is very stable, no stem may be required. My preference is to use a short cemented stem or hybrid conical stem in patients with good metaphyseal bone. If significant metaphyseal bone loss is present, I will use a porous cone with either a short cemented stem, hybrid cylindrical or offset stem depending on the primary stability of the cone and whether the femoral or tibial component can be placed in an optimal position in patients with good metaphyseal bone

We prospectively studied 48 hips in 47 patients with a mean age of 59.6 years and reviewed the results after a mean period of follow up of 9 (range 7 – 12) years following revision arthroplasty for aseptic loosening using a primary HA-coated femoral stem. 1.8 Previous operations per patient were performed, ranging from 1 to 8, all patients had a femoral defect class 1 or 2 according to Paprosky. Clinical outcome was good with a mean postoperative HHS of 90 points. Pain was absent in 89%, a limp was present in 36% and 41% used a walking aid. There were 5 re-operations: 4 recurrent dislocations and 1 progressive PE wear necessitated cup revision. At 6 years, 39% cancellous densifications were seen, especially in non-tightly fitted prostheses, mainly in zone 2 and 6. Cortical thickening was seen in 30%, especially in tightly-fitted prostheses, mainly in zone 3 and 5. These differences in bone behaviour were significant (p‘0.001) and were not related with various clinical parameters. These phenomena started to appear from 6 months onwards with increasing frequency with longer follow up. The stem survival up till 9 years is 100%, no stem is pending revision at the latest follow up. We conclude that the primary Mallory Head HA-coated femoral prosthesis is a suitable prosthesis to use in revision procedures in younger patients with a lower class femoral defect. We also noticed that the radiological remodelling phenomena are not prosthesis related but femoral canal fit dependent

Revision of massive femoral defects in revision hip arthroplasty is extremely difficult. This study assesses defects where bone loss extends to the isthmus of the femur. By using a medial allogeneic femoral graft in a wedge fashion, rotational and axial stability of the femoral implant is augmented, allowing bone ingrowth to occur. The technique is described which is simple, inexpensive and readily available in most institutions. A medial allogeneic femoral strut graft is assessed in hip arthroplasty revision to improve implant stability and thereby promote bony ingrowth into the implant. Thirty-three revision arthroplasties were preformed in twenty-nine patients (avg. age 63.7 yrs) using a fully-porous coated implant of eight or ten inch length. All patients had a Paprosky Type III or IV femoral defect. The implants, by definition were press-fit at or past the isthmus. To aid ingrowth and to decrease axial and rotational stresses, a medial femoral strut graft was wedged into the remaining medial host bone and under the collar of the implant. Cabling was utilized to prevent dislodgement of the graft from the implant and host. A radiographic and clinical comparison to a series of similar defects without grafting was performed for a minimum of thirty-five month follow-up. Twenty-eight of the thirty-three implants had radiographic evidence of ingrowth with migration of only two millimeters (average). Medial femoral strut grafting displayed much better potential for ingrowth and decreased potential for migration. Harris hip scores averaged eighty-one from a preoperative score of thirty-two. Cost of the grafts averaged $2100 cheaper compared to a bulk structural graft which would otherwise have been used in this situation. Medial femoral strut grafts augment initial implant stability to allow for implant in- growth. The advantages of the medial strut grafts are decreased cost, improved stability, and improved implant in- growth potential

We report our experience of revision total hip replacement (THR) using the Revitan curved modular titanium fluted revision stem in patients with a full spectrum of proximal femoral defects. A total of 112 patients (116 revisions) with a mean age of 73.4 years (39 to 90) were included in the study. The mean follow-up was 7.5 years (5.3 to 9.1). A total of 12 patients (12 hips) died but their data were included in the survival analysis, and four patients (4 hips) were lost to follow-up. The clinical outcome, proximal bone regeneration and subsidence were assessed for 101 hips. The mean Harris Hip Score was 88.2 (45.8 to 100) after five years and there was an increase of the mean Barnett and Nordin-Score, a measure of the proximal bone regeneration, of 20.8 (-3.1 to 52.7). Five stems had to be revised (4.3%), three (2.9%) showed subsidence, five (4.3%) a dislocation and two of 85 aseptic revisions (2.3%) a periprosthetic infection. . At the latest follow-up, the survival with revision of the stem as the endpoint was 95.7% (95% confidence interval 91.9% to 99.4%) and with aseptic loosening as the endpoint, was 100%. Peri-prosthetic fractures were not observed. We report excellent results with respect to subsidence, the risk of fracture, and loosening after femoral revision using a modular curved revision stem with distal cone-in-cone fixation. A successful outcome depends on careful pre-operative planning and the use of a transfemoral approach when the anatomy is distorted or a fracture is imminent, or residual cement or a partially-secured existing stem cannot be removed. The shortest appropriate stem should, in our opinion, be used and secured with > 3 cm fixation at the femoral isthmus, and distal interlocking screws should be used for additional stability when this goal cannot be realised. Cite this article: Bone Joint J 2014;96-B:889–95

Introduction and Objectives: We analysed a series of 27 patients who underwent salvage total hip replacement and femoral packing with bone bank allograft for the treatment of femoral defects. We analyzed results clinically and radiographically. Materials and Methods: This study involved 27 hip salvage surgeries in 27 patients. The patients were treated between March 1997 and April 1999 with a follow-up period of 4–6 years. Femoral defects were classified according to AAOS criteria. Clinical results were assessed using the Harris scale. Radiographic studies were performed postoperatively, at 6 months, at one year after treatment, at 4 years, and in 6 cases, at 6 years. We also analysed clinical complications, technical problems, and sinking of the prosthesis into the femoral canal. Results: Of these patients, 80% did not present with pain one year after treatment, and 85% could walk without assistance. The graft was incorporated in 90% of cases. Sinking of the prosthesis without indications of loosening occurred in less than 50% of cases. In one patient is was necessary to repeat treatment due to sinking and loosening of the femoral component, and in another case it was necessary to remove the prosthesis due to infection. Discussion and Conclusions: The method of impaction of morselised cancellous bone into the femoral canal as described by Ling et al. has been shown in recent years to be reliable and reproducible in cases of femoral canal defects resulting from osteolysis and significant losses of cortical bone. Bone stock is restored, thus paving the way for future revisions with distal diaphyseal attachment revision prosthesis. Continued evaluation of the allograft impaction technique in femoral component revision shows optimal results after 5 years of follow up

Osteolysis commonly causes total knee replacement (TKR) failure, often associated with asymptomatic large defects. Detection and size estimation of lytic defects is important for the indications and planning of revision surgery. Our study compares the utility of fluoroscopic-guided plain X-rays and computed topography (CT) in osteolysis detection and volume appreciation. Three cadaveric specimens were imaged at baseline and following the creation of reamed defects (small, medium and large approximately = 1, 5 & 10 cm3 volume respectively) in the tibia and femur with TKR component implantation at each timepoint. Imaging was with fluoroscopic-guided plain X-rays (Anteroposterior & Lateral [APL], Paired Oblique [OBL]) as well as rapid-acquisition spiral Computed Topography [CT] with a beam-hardening artefact removal algorithm. Three arthroplasty surgeons estimated the size of the lesion, if present, and confidence (none=0, fair=1, excellent=2) in their assessment on randomly presented images. Each surgeon performed two assessments of each image one month apart. The accuracy of detecting lesions was determined using the area under the receiver-operating curve (AU-ROC) obtained from a logistic regression with adjustment for assessment sequence, observer, knee and bone. Volume appreciation and assessor confidence were determined using Kappa and the mean average of confidence scores respectively. The AU-ROC using combinations of either APL/OBL/CT (0.83) or OBL/CT (0.83) resulted in superior detection of lesions (p<0.05) compared to APL (0.75) or OBL alone (0.77). Correct volume appreciation was highest with APL/OBL/CT (kappa=0.52), followed by APL/OBL (0.51) and was superior (p<0.05) to APL (0.29) or CT alone (0.31). Small and medium defects were more often missed than large with all modalities (20.3 vs. 39.7 %). Femoral defects were missed more often than tibial defects (40% vs. 28.7%) and small lesions missed more with CT (50%) versus APL (48%) and Oblique (40%). CT missed 19% of large sized defects, attributed mostly to femoral (29.1%) rather than tibial defects (8.3%). Greater confidence was derived from use of CT (1.29) and APL (1.19) [Interquartile range (IQR) 1,2] when compared to OBL (.98, IQR 1,1) [p<.01]. Also, there was greater confidence regarding judgement of tibial defects (1.25, IQR 1,2) compared with femoral defects (1.05, IQR 1,1) [p<.01]. Combining all imaging modalities was synergistic and the most sensitive and specific means of defect detection and volume appreciation. CT provided more confidence, superior detection and volume appreciation when used in combination with APL/OBL versus APL/OBL alone. There is also additional value when APL is combined with OBL

Purpose: Poor bone quality is a common challenge to orthopaedic surgeons and frequently leads to complications such as non union and implant failure, particularly the elderly whose capacity for tissue repair is significantly reduced. The current study was designed to determine if bone marrow derived mesenchymal stem cells (MSC) seeded in dense collagen scaffolds and delivered to a surgically-induced femoral defect will expedite bone healing. Method: Ex Vivo: MSC isolated from four month old donor mice were expanded ex vivo, seeded into hydrated type I collagen, which was subjected to unconfined compression to generate dense collagen scaffolds. The cell-seeded scaffolds were then cultured for up to 21 days. MSC viability was monitored using the AlamarBlue. ®. metabolic assay and differentiation into osteoblasts using alkaline phosphatase (ALP) and von Kossa stain. In Vivo: A 3mm x 1mm window defect was drilled in the femur of elderly recipient C57Bl6 and C3H mice. The C3H mice were assigned to one of two study groups:. LEFT femur drill hole alone; RIGHT femur acellular scaffold. LEFT femur acellular scaffold; RIGHT femur cell-seeded scaffold. The quantity and quality of bone regeneration was assessed after 2 and 4 weeks using micro computed tomography (mCT) and histology. Results: Ex Vivo: The dense collagen scaffold had superior mechanical properties and supported the survival and differentiation of MSC into osteoblasts up to 21 days in culture. Cells in uncompressed gels and those in compressed gels in non-osteogenic medium, had fewer ALP-positive cells at early time point and less mineral deposited at later times compared with those in compressed gels in osteogenic medium. In Vivo: A high incidence of postoperative fracture was seen in C57Bl6 mice compared with age matched C3H mice in the first study group. Furthermore, the empty surgical defect healed more rapidly than that containing the dense collagen scaffold, in which bone volume compared with tissue volume (BV/TV), trabecular number (Tb.N.) and connectivity were lower. In study group two, bone regeneration was evident at 2 weeks post operative and transplantation of MSC-seeded dense collagen scaffolds resulted in higher BV/TV, Tb.N. and trabecular connectivity compared with the acellular dense collagen scaffold. Conclusion: Bone fragility in elderly C57Bl6 mice led to post operative fracture after generation of a non-critical sized drill hole defect in the proximal femur whereas age-matched C3H mice with higher bone mass sustained no fractures. Dense collagen scaffolds supported the survival and osteoblast differentiation of bone marrow derived MSC in 3D culture. Their superior mechanical properties allowed for transplantation into non-critical sized femoral defects, suggesting the approach shows promise as adjunct therapy for use with bone grafts and implants in patients with poor quality bone

Using an institutional database we have identified over 1000 femoral revisions using extensively porous-coated stems. Using femoral re-revision for any reason as an endpoint, the survivorship is 99 ± 0.8% (95% confidence interval) at 2 years, 97 ± 1.3% at 5 years, 95.6 ± 1.8% at 10 years, and 94.5 ± 2.2% at 15 years. Similar to Moreland and Paprosky, we have identified pre-revision bone stock as a factor affecting femoral fixation. When the cortical damage involved bone more than 10cm below the lesser trochanter, the survivorship, using femoral re-revision for any reason or definite radiographic loosening as an endpoint, was reduced significantly, as compared with femoral revisions with less cortical damage. In addition to patients with Paprosky Type 3B and 4 femoral defects, there are rare patients with femoral canals smaller than 13.5mm or larger than 26mm that are not well suited to this technique. Eight and 10 inch stems 13.5 or smaller should be used with caution if there is no proximal bone support for fear of breaking. Patients with canals larger than 18mm may be better suited for a titanium tapered stem with flutes. While a monolithic stem is slightly more difficult for a surgeon to insert than a modular femoral stem there is little worry about taper junction failure

The goals of revision total hip on the femoral side are to achieve long term stable fixation, improve quality of life and minimise complications such as intra-operative fracture or dislocation. Ideally these stems will preserve or restore bone stock. Modular titanium stems were first introduced in North America around 2000. They gained popularity as an option for treating Paprosky 3B and 4 defects. Several studies at our institution have compared modular titanium stems with monoblock cobalt chromium stems. The main outcomes of interest were quality of life. We also looked at complications such as intra-operative fracture and post-operative dislocation. We also compared these 2 stems with respect to restoration or preservation of bone stock. In 2 studies we showed that modular titanium stems gave superior functional outcomes as well as decreased complications compared to a match cohort of monoblock cobalt chromium stems. As mentioned, one of the initial reasons for introduction of these stems was to address larger femoral defects where failure rates with monoblock cobalt chromium stems were unacceptably high. We followed a group of 65 patients at 5–10 years post revision with a modular fluted titanium stem. Excellent fixation was obtained with no cases of aseptic loosening. However, there were 5 cases of fracture of the modular junction. Due to concerns of fracture of the modular junction, more recently, at our institution, we have switched to almost 100% monoblock fluted titanium stems. We recently reviewed our first 100 cases of femoral revision with a monoblock stem. Excellent fixation was achieved with no cases of aseptic loosening. Quality of life outcomes were similar to our previous reported series on modular tapered titanium stems. Both monoblock and modular fluted titanium stems can give excellent fixation and excellent functional outcomes. This leaves a choice for the surgeon. For the low volume revision surgeon modular tapered stems are probably the right choice. Higher volume surgeons or surgeons very comfortable with performing femoral revision may want to consider monoblock stems. If one is making the switch it would be easiest to start with a simple case. Such a case would be one that can be done with a endofemoral approach. In this approach the greater trochanter is available as the key landmark for reaming. After the surgeon is comfortable with this stem more complex cases can easily be handled with the monoblock stem. In summary, both modular and monoblock titanium stems are excellent options for femoral revision. As one becomes more familiar with the monoblock stem it can easily become your workhorse for femoral revision. At our institution we introduced a monoblock titanium stem in 2011. It started out at 50% of cases and now it is virtually used in almost 100% of revision cases

The August 2024 Oncology Roundup³⁶⁰ looks at: What factors are associated with osteoarthritis after cementation for benign aggressive bone tumour of the knee joint: a systematic review and meta-analysis; Recycled bone grafts treated with extracorporeal irradiation or liquid nitrogen freezing after malignant tumour resection; Intercalary resection of the tibia for primary bone tumours: are vascularized fibula autografts with or without allografts a durable reconstruction?; 3D-printed modular prostheses for the reconstruction of intercalary bone defects after joint-sparing limb salvage surgery for femoral diaphyseal tumours; Factors influencing the outcome of patients with primary Ewing’s sarcoma of the sacrum; The significance of surveillance imaging in children with Ewing’s sarcoma and osteosarcoma; Resection margin and soft-tissue sarcomas of the extremities treated with limb-sparing surgery and postoperative radiotherapy.

Aims

The aim of this modified Delphi process was to create a structured Revision Hip Complexity Classification (RHCC) which can be used as a tool to help direct multidisciplinary team (MDT) discussions of complex cases in local or regional revision networks.

We maintain a database on 1000 femoral revisions using extensively porous-coated stems. Using femoral rerevision for any reason as an endpoint, the survivorship is 99 ± 0.8% (95% confidence interval) at 2 years, 97 ± 1.3% at 5 years, 95.6 ± 1.8% at 10 years, and 94.5 ± 2.2% at 15 years. Similar to Moreland and Paprosky, we have identified prerevision bone stock as a factor affecting femoral fixation. When the cortical damage involved bone more than 10 cm below the lesser trochanter, the survivorship, using femoral rerevision for any reason or definite radiographic loosening as an endpoint, was reduced significantly, as compared with femoral revisions with less cortical damage. In addition to patients with Paprosky type 3B and 4 femoral defects there are rare patients with femoral canals smaller than 13.5 mm or larger than 26 mm that are not well suited to this technique. Eight and 10 inch stems 13.5 mm or smaller should be used with caution if there is no proximal bone support for fear of breaking. Patients with canals larger than 18 mm may be better suited for a titanium tapered stem with flutes. While a monolithic stem is slightly more difficult for a surgeon to insert than a modular femoral stem there is little worry about taper junction failure

Using an institutional database we have identified over 1000 femoral revisions using extensively porous-coated stems. Using femoral re-revision for any reason as an endpoint, the survivorship is 99 ± 0.8% (95% confidence interval) at 2 years, 97 ± 1.3% at 5 years, 95.6 ± 1.8% at 10 years, and 94.5 ± 2.2% at 15 years. Similar to Moreland and Paprosky, we have identified pre-revision bone stock as a factor affecting femoral fixation. When the cortical damage involved bone more than 10 cm below the lesser trochanter, the survivorship, using femoral re-revision for any reason or definite radiographic loosening as an endpoint, was reduced significantly, as compared with femoral revisions with less cortical damage. In addition to patients with Paprosky type 3B and 4 femoral defects, there are rare patients with femoral canals smaller than 13.5 mm or larger than 26 mm that are not well suited to this technique. Eight and 10 inch stems 13.5 or smaller should be used with caution if there is no proximal bone support for fear of breaking. Patients with canals larger than 18 mm may be better suited for a titanium tapered stem with flutes. While a monolithic stem is slightly more difficult for a surgeon to insert than a modular femoral stem there is little worry about taper junction failure

Aims

The aim of this study was to examine the implant accuracy of custom-made partial pelvis replacements (PPRs) in revision total hip arthroplasty (rTHA). Custom-made implants offer an option to achieve a reconstruction in cases with severe acetabular bone loss. By analyzing implant deviation in CT and radiograph imaging and correlating early clinical complications, we aimed to optimize the usage of custom-made implants.

The goals of revision total hip on the femoral side are to achieve long term stable fixation, improve quality of life and minimise complications such as intra-operative fracture or dislocation. Ideally these stems will preserve or restore bone stock. Modular titanium stems were first introduced in North America around 2000. They gained popularity as an option for treating Paprosky 3B and 4 defects. Several studies at our institution have compared the modular titanium stems with monoblock cobalt chromium stems. The main outcomes of interest were quality of life. We also looked at complications such as intra-operative fracture and post-operative dislocation. We also compared these 2 stems with respect to restoration or preservation of bone stock. In 2 studies we showed that modular titanium stems gave superior functional outcomes as well as decreased complications compared to a match cohort of monoblock cobalt chromium stems. As mentioned one of the initial reasons for introduction of these stems was to address larger femoral defects where failure rates with monoblock cobalt chromium stems were unacceptably high. We followed a group of 65 patients at 5–10 years post-revision with a modular fluted titanium stem. Excellent fixation was obtained with no cases of aseptic loosening. However, there were 5 cases of fracture of the modular junction. Due to concerns of fracture of the modular junction more recently at our institution we have switched to almost 100% monoblock fluted titanium stems. We recently reviewed our first 100 cases of femoral revision with monoblock stem. Excellent fixation was achieved with no cases of aseptic loosening. Quality of life outcomes were similar to our previous reported series on modular tapered titanium stems. Both monoblock and modular fluted titanium stems can give excellent fixation and excellent functional outcomes. This leaves a choice for the surgeon. For the low volume revision surgeon modular tapered stems are probably the right choice. Higher volume surgeons or surgeons very comfortable with performing femoral revision may want to consider monoblock stems. If one is making the switch it would be easiest to start with a simple case. Such a case would be one that can be done with an endofemoral approach. In this the greater trochanter is available as the key landmark for reaming. After the surgeon is comfortable with this stem more complex cases can easily be handled with the monoblock stem. In summary, both modular and monoblock titanium stems are excellent options for femoral revision. As one becomes more familiar with the monoblock stem it can easily become your workhorse for femoral revision. At our institution we introduced a monoblock titanium stem in 2011. It started out at 50% of cases and now it is virtually used in almost 100% of revision cases

Revision of the failed femoral component of a total hip arthroplasty can be challenging. Multiple reconstructive options are available and the operation itself can be particularly difficult and thus meticulous preoperative planning is required to pick the right “tool” for the case at hand. The Paprosky Femoral Classification is useful as it helps the surgeon determine what bone stock is available for fixation and hence, which type of femoral reconstruction is most appropriate. Monoblock, fully porous coated diaphyseal engaging femoral components are the “work-horse” of femoral revision. This type of a stem is used in my practice for Type 1–3a femoral defects. These stems are not used, however, in the following situations: The canal diameter is greater than 18mm; There is less than 4cm available for distal fixation in the isthmus; There is proximal femoral remodeling into retroversion. While many surgeons often believe that revision femoral components need to be “long”, they really only need to be long enough to engage 4cm of intact femoral isthmus, which is oftentimes the shortest, “primary length” fully porous coated stem. Advantages of using a shorter revision stem include: Easier surgical technique as you avoid the femoral bow, with a lower risk of fracture and under-sizing; Preserves bone stock for future revisions if required; Easier to remove if required

Aims

The use of 3D-printed titanium implant (DT) can effectively guide bone regeneration. DT triggers a continuous host immune reaction, including macrophage type 1 polarization, that resists osseointegration. Interleukin 4 (IL4) is a specific cytokine modulating osteogenic capability that switches macrophage polarization type 1 to type 2, and this switch favours bone regeneration.

The goals of revision total hip on the femoral side are to achieve long term stable fixation, improve quality of life and minimise complications such as intra-operative fracture or dislocation. Ideally these stems will preserve or restore bone stock. Modular titanium stems were first introduced in North America around 2000. They gained popularity as an option for treating Paprosky 3B and 4 defects. Several studies at our institution have compared the modular titanium stems with monoblock cobalt chromium stems. The main outcomes of interest were quality of life. We also looked at complications such as intra-operative fracture and post-operative dislocation. We also compared these 2 stems with respect to restoration or preservation of bone stock. In two studies we showed that modular titanium stems gave superior functional outcomes as well as decreased complications compared to a matched cohort of monoblock cobalt chromium stems. As mentioned one of the initial reasons for introduction of these stems was to address larger femoral defects where failure rates with monoblock cobalt chromium stems were unacceptably high. We followed a group of 65 patients at 5–10 years post-revision with a modular fluted titanium stem. Excellent fixation was obtained with no cases of aseptic loosening. However, there were 5 cases of fracture of the modular junction. Due to concerns of fracture of the modular junction more recently, at our institution we have switched to almost 100% monoblock fluted titanium stems. We recently reviewed our first 100 cases of femoral revision with monoblock stem. Excellent fixation was achieved with no cases of aseptic loosening. Quality of life outcomes were similar to our previous reported series on modular tapered titanium stems. Both monoblock and modular fluted titanium stems can give excellent fixation and excellent functional outcomes. This leaves a choice for the surgeon. For the low volume revision surgeon modular tapered stems are probably the right choice. Higher volume surgeons or surgeons very comfortable with performing femoral revision may want to consider monoblock stems. If one is making the switch it would be easiest to start with a simple case. Such a case would be one that can be done through an endofemoral approach. In this the greater trochanter is available as the key landmark for reaming. After the surgeon is comfortable with this system more complex cases can easily be handled with the monoblock stem. In summary, both modular and monoblock titanium stems are excellent options for femoral revision. As one becomes more familiar with the monoblock stem it can easily become your workhorse for femoral revision. At our institution, we introduced a monoblock titanium stem in 2011. It started out at 50% of cases and now it is virtually used in almost 100% of revision cases

Introduction. As the proximal femoral bone is generally compromised in failed total hip arthroplasty, achievement of solid fixation with a new component can be technically demanding. Clinical studies have demonstrated good medium-term results after revision total hip arthroplasty using modular fluted and tapered distal fixation stems, but, to our knowledge, long-term outcomes have been rarely reported in the literature. The purpose of this study was to report the minimum ten-year results of revision total hip arthroplasty using a modular fluted and tapered distal fixation stem. Materials & Methods. We analyzed 40 revision THAs performed in using a modular fluted and tapered distal fixation stem (Fig. 1) between December 1998 and February 2004. There were 11 men (12 hips) and 28 women (28 hips) with a mean age of 59 years (range, 38 to 79 years) at the time of revision THA. According to the Paprosky classification of femoral defects, 5 were Type II, 24 were Type IIIA, and 11 were Type IIIB. An extended trochanteric osteotomy was carried out in 21 (52%) of the 40 hips. Patients were followed for a mean of 11.7 years (range, 10 to 15 years). Results. The mean Harris hip score improved from 41 points preoperatively to 85 points at the time of the latest follow-up. A total of 4 hips required additional surgery. One hip had two-stage reconstruction due to deep infection, one had liner and head exchange for ceramic head fracture, one had isolated cup re-revision for aseptic loosening, and one had constrained component revision for recurrent dislocation. No repeat revision was performed due to aseptic loosening of femoral stem. There was no stem fracture at the modular junction. Kaplan-Meier survivorship with an end point of stem re-revision for any reason was 98.1% at 11.7 years (Fig. 2), and, for aseptic stem loosening, the best-case scenario was 100% and the worst-case scenario was 91.9% at 11.7 years (Fig. 3). Conclusions. A modular fluted and tapered distal fixation stem continued to provide a reliable fixation at a minimum ten years after revision THA and can therefore be recommended as a promising option for challenging revision situations with femoral bone defects

I use monolithic, cylindrical, fully porous coated femoral components for many femoral revisions. Our institutional database holds information on 1000 femoral revisions using extensively porous-coated stems. To date, 27 stems have been re-revised (14 for loosening, 4 for infection, 7 for stem fracture, 2 at time of periprosthetic femoral fracture). Using femoral re-revision for any reason as an end point, the survivorship is 99 ± 0.8% (95% confidence interval) at 2 years, 97 ± 1.3% at 5 years, 95.6 ± 1.8% at 10 years, and 94.5 ± 2.2% at 15 years. Similar to Moreland and Paprosky, we have identified pre-revision bone stock as a factor affecting femoral fixation. Among the 777 femoral revisions graded for femoral bone loss, 59% of the femurs were graded as having no cortical damage before the revision, 29% had cortical damage extending no more than 10 cm below the lesser trochanter, and 12% had cortical damage that extended more than 10 cm below the lesser trochanter. When the cortical damage involved bone more than 10 cm below the lesser trochanter, the survivorship, using femoral re-revision for any reason or definite radiographic loosening as an end point, was reduced significantly, as compared with femoral revisions with less cortical damage. In addition to patients with Paprosky type 3B and 4 femoral defects there are rare patients with femoral canals smaller than 13.5 mm or larger than 26 mm that are not well suited to this technique. Eight and 10” stems 13.5 or smaller should be used with caution if there is no proximal bone support for fear of breaking. Patients with canals larger than 18 mm may be better suited for a titanium tapered stem with flutes. While a monolithic stem is slightly more difficult for a surgeon to insert than a modular femoral stem there is little worry about taper junction failure

Introduction. The reconstructive hip surgeon is commonly faced with complex cases where severe bone loss makes conventional revision techniques difficult or impossible. This problem is likely to increase in future, as there is a good correlation between the degree of bone loss seen and number of previous total hip operations. In such situations, one alternative is the use impaction allografting with cement. This has captured the attention of the orthopaedic community because of its potential for reconstituting femoral bone stock. History. The first clinical reports of impaction allografting on the femoral side were in relation to revision with cementless stems. The use of morselised bone with cement on the femoral side was first reported by the Exeter group. Biology. The great enthusiasm with which this technique has been received is related to its biological potential to increase bone stock. The rapid revascularization, incorporation and remodelling of morselised compacted cancellous allograft differs dramatically from structural allografting where bone ingrowth usually is limited to 2–3 mm. Histological evidence for bony reconstitution has been presented from postmortem retrievals, and from biopsies at the time of trochanteric wire removal. Impaction allografting, performed with great attention to detail using appropriate equipment, represents an exciting reconstructive solution for contained femoral defects. Its role in larger and combined defects remains open to scrutiny. A number of technical issues with regards to allograft preparation and prosthetic design have been resolved over the past decade. The necessary intra-operative precautions are now appreciated, and the high complication rates seen in some centers have been explained in simple terms. Careful observation and cautious optimism are necessary as further refinements may well improve the predictability of the clinical results and expand the indications for this important addition to the armamentarium of the revision surgeon. The technique of impaction allografting of the femur has great potential, and is here to stay as a reconstructive solution to the deficient proximal femur in revision hip arthroplasty. Although many questions remain unanswered, the capacity for impaction allografting to act as a truly biologic augmentation of the proximal femur makes this technique the modern bridge from revision arthroplasty to reconstructive hip surgery

I prefer monolithic, cylindrical, fully porous coated femoral components for most femoral revisions. Our institutional database holds information on 1000 femoral revisions using extensively porous-coated stems. To date, 27 stems have been rerevised (14 for loosening, 4 for infection, 7 for stem fracture, 2 at time of periprosthetic femoral fracture). Using femoral rerevision for any reason as an end point, the survivorship is 99 ± 0.8% (95% confidence interval) at 2 years, 97 ± 1.3% at 5 years, 95.6 ± 1.8% at 10 years, and 94.5 ± 2.2% at 15 years. Similar to Moreland and Paprosky, we have identified prerevision bone stock as a factor affecting femoral fixation. Among the 777 femoral revisions graded for femoral bone loss, 59% of the femurs were graded as having no cortical damage before the revision, 29% had cortical damage extending no more than 10cm below the lesser trochanter, and 12% had cortical damage that extended more than 10cm below the lesser trochanter. When the cortical damage involved bone more than 10cm below the lesser trochanter, the survivorship, using femoral rerevision for any reason or definite radiographic loosening as an end point, was reduced significantly, as compared with femoral revisions with less cortical damage. In addition to patients with Paprosky type 3B and 4 femoral defects there are rare patients with femoral canals smaller than 13.5mm or larger than 26mm that are not well suited to this technique. Eight and 10-inch stems 13.5 or smaller should be used with caution if there is no proximal bone support for fear of breaking. Patients with canals larger than 18mm may be better suited for a titanium tapered stem with flutes. While a monolithic stem is slightly more difficult for a surgeon to insert than a modular femoral stem there is little worry about taper junction failure

Autogenous bone grafting limitations have motivated the development of Tissue-Engineered (TE) biomaterials that offer an alternative as bone void fillers. However, the lack of a blood supply within implanted constructs may result in avascular necrosis and construct failure. 1. The aim of this project was to investigate the potential of novel TE constructs to promote vascularisation and bone defect repair using two distinct approaches. In Study 1, we investigated the potential of a mesenchymal stem cell (MSC) and endothelial cell (EC) co-culture to stimulate pre-vascularisation of biomaterials prior to in vivo implantation. 2. In Study 2, we investigated the potential of TE hypertrophic cartilage to promote the release of angiogenic factors such as VEGF, vascular invasion and subsequent endochondral bone formation in an in vivo model. Collagen-only (Coll), collagen-glycosaminoglycan (CG) and collagen-hydroxyapatite (CHA) scaffolds were fabricated by freeze-drying. 3. , seeded with cells and implanted into critical-sized calvarial and femoral defects in immunocompetent rats. In Study 1, Coll and CG scaffolds were initially seeded with ECs, allowed to form capillary-like networks before the delayed addition of MSCs and continued culture prior to calvarial implantation. In Study 2, CG and CHA scaffolds were seeded with MSCs and cultured under chondrogenic and subsequent hypertrophic conditions to form a cartilage pre-cursor prior to calvarial and femoral implantation in vivo. MicroCT and histomorphometry quantification demonstrated the ability of both systems to support increased bone formation compared to controls. Moreover, the greatest levels of bone formation were observed in the CG groups, notably in those containing cartilage tissue (Study 2). Assessment of the immune response suggests the addition of MSCs promotes the polarisation of macrophages away from inflammation (M1) towards a pro-remodelling phenotype (M2). We have developed distinct collagen-based systems that promote vascularisation and ultimately enhance bone formation, confirming their potential as advanced strategies for bone repair applications

Aims

There is a paucity of long-term studies analyzing risk factors for failure after single-stage revision for periprosthetic joint infection (PJI) following total hip arthroplasty (THA). We report the mid- to long-term septic and non-septic failure rate of single-stage revision for PJI after THA.

Aims

To fully verify the reliability and reproducibility of an experimental method in generating standardized micromotion for the rat femur fracture model.

To document the medium term results of the use of a fluted tapered titanium femoral stem in revision total hip arthroplasty. 70 patients undergoing total hip revision using a tapered grit blasted titanium modular stem were reviewed at a mean follow up time of 47 months. No bone graqfts were used. Femoral defects were classified according to Pak and Paprosky and the femoral bone quality was assessed with the Bohm and Bischel system. Clinical function was assessed by the Oxford Hip Score. Radiographic analysis was performed in all cases. The results of the use of this prosthesis compares favourably with other revision stems. The Oxford Hip Scores compare favourably with the results for revisions recorded in the New Zealand National Joint Register (24.3) Although technically demanding this stem offers a very satisfactory solution for revision of total hips in most circumstances

Background: The aim of this prospective multi-center study was to evaluate the clinical and radiological results of a total of 314 uncemented femoral stem revisions using the modular MRP-titanium system. Methods: 305 patients (111 males, 194 females, mean age 67.7) with 314 MRP-titanium systems were followed-up for a meantime of 3.2 years (1 to 9 years). Pre- and post-operatively all patients were clinically documented using the Harris hip score. Radiologically, the preoperative bony defects were assessed by the Paprosky classification. Post-operatively, periprosthetic bone remodeling was evaluated on the basis of radiographic evidence of bone apposition or resorption. The modular MRP-titanium system has proven to be valuable in quite problematic cases of hip revision arthroplasty with extensive femoral defects. The system allows intraoperative adaptation of implant length and antetorsion angle to the actual situation, a feature not provided by non-modular femoral revision implants

I prefer monolithic, cylindrical, fully porous coated femoral components for most femoral revisions. Our institutional database holds information on 1000 femoral revisions using extensively porous-coated stems. To date, 27 stems have been rerevised (14 for loosening, 4 for infection, 7 for stem fracture, 2 at time of periprosthetic femoral fracture). Using femoral rerevision for any reason as an end point, the survivorship is 99 ± 0.8% (95% confidence interval) at 2 years, 97 ± 1.3% at 5 years, 95.6 ± 1.8% at 10 years, and 94.5 ± 2.2% at 15 years. Similar to Moreland and Paprosky, we have identified prerevision bone stock as a factor affecting femoral fixation. Among the 777 femoral revisions graded for femoral bone loss, 59% of the femurs were graded as having no cortical damage before the revision, 29% had cortical damage extending no more than 10 cm below the lesser trochanter, and 12% had cortical damage that extended more than 10 cm below the lesser trochanter. When the cortical damage involved bone more than 10 cm below the lesser trochanter, the survivorship, using femoral rerevision for any reason or definite radiographic loosening as an end point, was reduced significantly, as compared with femoral revisions with less cortical damage. In addition to patients with Paprosky type 3B and 4 femoral defects there are rare patients with femoral canals smaller than 13.5 mm or larger than 26 mm that are not well suited to this technique. Eight and 10” stems 13.5 or smaller should be used with caution if there is no proximal bone support for fear of breaking. Patients with canals larger than 18 mm may be better suited for a titanium tapered stem with flutes. While a monolithic stem is slightly more difficult for a surgeon to insert than a modular femoral stem there is little worry about taper junction failure

Introduction:. The reconstructive hip surgeon is commonly faced with complex cases where severe bone loss makes conventional revision techniques difficult or impossible. This problem is likely to increase in future, as there is a good correlation between the degree of bone loss seen and number of previous total hip operations. In such situations, one alternative is the use of impaction allografting with cement. History:. The first clinical reports of impaction allografting on the femoral side were in relation to revision with cementless stems. The use of morselised bone with cement on the femoral side was first reported by the Exeter group. Biology:. The great enthusiasm with which this technique has been received is related to its biological potential to increase bone stock. The rapid revascularization, incorporation and remodeling of morselised compacted cancellous allograft differs dramatically from structural allografting where bone ingrowth usually is limited to 2mm to 3mm. Histological evidence for bony reconstitution has been presented from postmortem retrievals, and from biopsies at the time of trochanteric wire removal. Type of bone:. The size of the bone chips used as morselised allograft is important. The graft behaves as a friable aggregate and its resistance to complex forces depends on grading, normal load and compaction. It is recommended that particles of 3–5mm in diameter make up the bulk of the graft. A bone slurry, such as that produced by blunted bone mills, or by the use of acetabular reamers or high speed burrs would not give satisfactory stability. A wide range of particle sizes is recommended in order to achieve the greatest stability. The cement mantle:. A satisfactory cement mantle is required to ensure the longevity of any cemented stem. The primary determinant of cement mantle thickness is the differential between the graft impactors and the final stem. All femoral impaction systems require careful design to achieve a cement mantle that is uninterrupted in its length and adequate in its thickness. Stem design:. The technique of impaction allografting on the femoral side was first and most successfully reported using a highly polished stem with a double tapered geometry and no collar. It is thought to be ideal for this technique as it can subside within the cement mantle, thus generating hoop stresses on the cement which creeps, potentially maintaining physiological loads on the supporting bone. The extension of this technique to other stems has led to some controversy. Confounding factors such as surgical technique, the impaction system available, the type and size of allograft bone used, and the extent of the preoperative bone loss, will undoubtedly continue to influence such comparisons. It appears that the exact stem configuration may not be as critical as its surface finish, the amount of graft impaction possible and the cement mantle produced. The introduction of longer stems and impactors in the last decade has undoubtedly further increased the scope of this technique. Conclusion:. Impaction allografting is the only technique currently available that reverses the loss of bone stock seen in a revision hip arthroplasty. Moreover, this technique does not sacrifice host tissue, and could facilitate further surgery. Impaction allografting, performed with great attention to detail using appropriate equipment, represents an exciting reconstructive solution for contained femoral defects

Background. An osteochondral defect in the knees of young active patients represents a treatment challenge to the orthopaedic surgeon. Early studies with allogenic cartilage transplantation showed this tissue to be immunologically privileged, showed fresh grafts to maintain hyaline cartilage, and surviving chondrocytes several years after implantation. Methods. Between January 1978 and October 1995 we enrolled 63 patients in a prospective non-randomised study of fresh osteochondral allografts for post-traumatic distal femur defects in our institute. Five international patients who were lost to follow-up were excluded from this study. The indications for the procedure were: patients younger than 50 years of age having unipolar post-traumatic defects, or osteochondritis dissecans larger than three cm in diameter and one cm in depth. Results. Fifty-eight patients, ages 11-48 (mean 28) were followed for 15-32 years (mean 21.8 years). Thirteen of the 58 grafts have subsequently required further surgery, with three having graft removal and ten converted to total knee arthroplasty. Three patients died during the study due to unrelated causes and are included in the survivorship curve. Kaplan-Meier survivorship analysis showed: 91%, 84%, 69%, and 59% graft survival at 10, 15, 20, and 25 years, respectively. Patients with surviving grafts had good function, with a mean modified Hospital for Special Surgery score of an average 86 at 20 years or more following the allograft transplantation surgery. Late osteoarthritic degeneration as was seen on radiographs was associated with lower Hospital for Special Surgery scores representing patients with poorer clinical outcome. Conclusion. The authors confirm the value of fresh osteochondral allograft as a long term solution for articular defect in the knees of young patients. We recommend the use of fresh osteochondral allograft for treatment of large osteochondral defects in the distal femur of young and active patients

Massive segmental bone defects in long bones remain a considerable clinical challenge and are a source for significant morbidity and prolonged dysfunction for the patient. We demonstrate the successful use of resorbable polylactide membranes as a scaffold for autologous bone graft in the treatment of a 10cm traumatic femoral bone defect. A 28-year-old male was involved in a motorcycle accident vs. tree at 140k/hr. He sustained a Gustillo grade 3b intercondylar fracture of his right femur, and a 10cm piece of his femoral bone found at the scene was brought to Emergency in a sterile container. He was taken to theatre for debridement and ORIF of the intercondylar fracture, with vacuum dressing cover. Day 5 post injury the patient returned to theatre and the LISS plate was revised to correct the rotation and 3cm shortening. The 10cm cortical defect now present was filled with antibiotic cement (Palacos) and delayed primary closure was performed. Day 21 post injury the cement spacer was removed and replaced with two polylactide membrane tubes, one within the medullary canal and the other around the outside of the bone. The “neocortical” space thus produced was grafted with cancellous autograft mixed with bone morphogenic protein (OP1, Stryker). The remainder of the post-operative course was uncomplicated and the patient was discharged home 5 days later. The patient was reviewed at the 6 week and 3 month mark post injury. The femoral defect demonstrated both radiological and clinical union at the 3 month mark and full weight bearing was permitted. His range of motion at that stage was 5 to 95 degrees with no sign of infection. The use of polylactide membranes as a scaffold in the treatment of segmental long bone defects is an excellent and relatively straightforward technique. Forming a space between the 2 tubes controls cancellous graft to the site of the cortical area where it is required and the polylactide membrane then resorbs over years producing CO2 and water. This case demonstrates that the use of polylactide membranes is safe and effective in the management of segmental long bone defects

Seventy patients with 91 congenital short femora are classified. Deformities resulting maternal Thalidomide treatment are compared with those where Thalidomide was not involved and genetic and epidemiological factors investigated in 50 patients. No essential anatomical difference was found between the two groups of femora but the whole complex of abnormalities differed: the Thalidomide group showed femur-tibia-radius anomalies while the non-Thalidomide garoup had femur-fibula-ulna anomalies, indicating either different aetiological factors or different timing of the insult to the foetus. Some differences between congenital coxa vara and congenital short femur associated with coxa vara are mentioned. Simple hypoplasia of the femur may possibly have a multifactorial genetic background since it is associated with other minor abnormalities of the limbs in these families, whereas environmental factors only are associated with the more severe femoral defects

Summary Statement. A coupled finite element - analytical model is presented to predict and to elucidate a clinical healing scenario where bone regenerates in a critical-sized femoral defect, bounded by periosteum or a periosteum substitute implant and stabilised via an intramedullary nail. Introduction. Bone regeneration and maintenance processes are intrinsically linked to mechanical environment. However, the cellular and subcellular mechanisms of mechanically-modulated bone (re-) generation are not fully understood. Recent studies with periosteum osteoprogenitor cells exhibit their mechanosensitivity in vitro and in situ. In addtion, while a variety of growth factors are implicated in bone healing processes, bone morphogenetic protein-2 (BMP-2) is recognised to be involved in all stages of bone regeneration. Furthermore, periosteal injuries heal predominantly via endochondral ossification mechanisms. With this background in mind, the current study aims to understand the role of mechanical environment on BMP-2 production and periosteally-mediated bone regeneration. The one-stage bone transport model [1] provides a clinically relevant experimental platform on which to model the mechanobiological process of periosteum-mediated bone regeneration in a critical-sized defect. Here we develop a model framework to study the cellular-, extracellular- and mechanically-modulated process of defect infilling, governed by the mechanically-modulated production of BMP-2 by osteoprogenitor cells located in the periosteum. Methods. Material properties of the healing callus and periosteum contribute to the strain stimulus sensed by osteoprogenitor cells therein. Using a mechanical finite element model, periosteal surface strains are first predicted as a function of callus properties. Strains are then input to a mechanistic mathematical model, where mechanical regulation of BMP-2 production mediates rates of cellular proliferation, differentiation and extracellular matrix (ECM) production, to predict healing outcomes. A parametric approach enables the spatial and temporal prediction of tissue regeneration via endochondral ossification. Predictions are compared with experimental, micro-computed tomographic and histologic, measures of cartilage and mineralised bone tissue regenerates. Model Predictions in Light of Experimental Case Studies: A validated baseline model predicts defect healing via cellular egression, extracellular matrix production and endochondral ossification, using parameters optimised to mimic experimental outcome measures at initial and final stages of healing. To elucidate which predictive model paramenters result in the intrinsic differences in experimental outcomes between defects bounded by either periosteum in situ or a periosteum substitute implant, model parameters are then varied by orders of magnitude to determine which factors exert dominant influence on achievement of experimentally relevant ECM area outcomes. Considering the complete set of parameters relevant to healing, the rate of osteoprogenitor to osteoblast differentiation, as well as rates of chondrocyte and osteoblast proliferation must be reduced and ECM production by chondrocytes must be increased from baseline, to achieve healing outcomes analogous to those observed in experiments. Discussion/Conclusion. The novel model framework presented here integrates a mechanistic feedback system, based on the mechanosensitivity of periosteal osteoprogenitor cells, which allows for modeling and prediction of tissue regeneration on multiple length and time scales

Introduction/Background: Diabetes Mellitus (DM) is a disease affecting over 21 million Americans resulting in numerous systemic effects, one of which is impaired bone healing. This study was designed to determine the osteoinductive capacity of MSC augmentation in allograft incorporation within a critical size femoral defect model in rats with DM. Materials/Methods: A 5mm critical size defect was created in the right femur of 40 male DM BB Wistar. Groups: DM/Allograft(All)+DBM and Non-DM/All+DBM: In two groups, the defect was filled with an allograft from a normal non-DM donor rat filled with approximately 0.05mm3 of DBM. DM/All+DBM/MSCs: In the experimental group, the defect was filled with All+DBM, and loaded with 10×106 MSC/mL. Histomorphometry: Animals were sacrificed at 4 and 8 weeks post-surgery, the femurs were processed for undecalcified histomorphometry, and seven areas of interest were measured. Results: At 4 and 8 weeks the average bone formation within the defect and total bone formation in the DM/All+DBM/MSC group and at 8 weeks the average total bone formation in the Non-DM/All+DBM group was significantly increased compared to the DM/All+DBM group. No significance was found comparing the Non-DM/All+DBM and DM/All+DBM/MSC groups. Discussion/Conclusions: This study reveals decreased amount of new bone formation in DM animals compared to Non-DM animals, showing the detrimental effects of DM upon allograft incorporation in a critical size defect. MSC augmentation resulted in new bone formation in DM animals similar to Non-DM animals, suggesting a potential role for MSC as an advjuvant during the process of allograft incorporation

Purpose of the study: The efficacy of a new oestrogeneration biomaterial should be demonstrated by in vivo grafts in animal models. Critical filling of bone defects in the rat could be useful as a model before beginning studies in large animals such as the sheep, goat or dog. Creation of a critical defect in the rat femur has been described, but not standardized, leading to difficult comparison between series. In this work, we wanted to establish a detailed standardisable surgical protocol for the creation of a 6 mm femur defect in the rat. Material and methods: We compared three anaesthesia protocols using 18 mal Wistar rats aged 21 weeks. We developed a surgical procedure enabling study of the advantages of the different commonly used surgical devices either in research or clinic to achieve osteosynthesis and a 6 mm bone defect. We also compared two types of fixation plates (and screws) available on the marker: a 1.2 mm thick titanium plate used for hand surgery and a 1.5 mm steel plate (veterinary medicine). Our postoperative clinical and radiographic follow-up was designed to validate our operative protocol and evaluate osteoregeneration. Results: We demonstrated first that the use of multimodal anaesthesia radically improved the clinical outcome in the animals. We then demonstrated that the 1.2 mm titanium plates recommended in other studies were too fragile in our model and that the steel 1.5 mm veterinary plates were more adapted. We finally demonstrated the superiority of surgical devises to create a defect and for osteosynthesis. We described a postoperative protocol offering satisfactory evaluation, clinically and radiographically. Discussion: This work is the first describing this protocol in detail. Improvements in feasibility and cost will make a readily exploitable model for other laboratories. The follow-up on this work should be aimed at improving the quality and pertinence of the analysis methods for the assessment of bone regeneration. Conclusion: We propose a mode for the critical defect in rat femur bone as a reliable model for the study of osteogenic capacities of new biomaterials

Introduction/Background: This study was designed to determine the osteoinductive capacity of rhBMP-2 in a non-critical size femoral defect in normal rats and rats with diabetes mellitus (DM). It was hypothesized that DM would result in impaired bone regeneration in the femoral non-critical size defects due to reduced bone formation and local delivery of rhBMP-2 would accelerate non-DM healing and normalize impaired bone healing in DM rats to the levels of Non-DM bone healing. Materials/Methods: A total of 80 BB Wistar rats were used in the project. A 3mm defect was created during surgery and stabilized with a polyimide plate and either a 0.05cc/11μg dose of rhBMP-2 or buffer in a collagen sponge was implanted into the defect. Microradiographs were taken on the day of sacrifice and processing of samples for PECAM-1 immunohistochemistry, histomorphometry, and mechanical testing was performed. Results: Both Non-DM and DM groups treated with rhBMP-2 demonstrated significantly higher radiographic scoring, total new bone formation, BV quantification, and mechanical testing parameters compared to those treated with buffer at all timepoints with no significance noted between Non-DM and DM groups treated with rhBMP-2. Discussion/Conclusions: This study reveals decreased amount of new bone formation in DM animals compared to Non-DM animals, showing the detrimental effects of DM upon bone healing. A single application of rhBMP-2 resulted in new bone formation in DM animals similar to Non-DM animals, suggesting a critical role for rhBMP-2 in ameliorating the deleterious effects of DM on bone regeneration and formation. Besides these groups 15 more DM rats were used for PECAM-1 staining for angiogenesis (7 with 1 loss at a 3 week time point) and mechanical testing (8 at a 9 week time point)

The aim of this study was to document the medium-term results of the use of fluted, tapered, titanium femoral stem in revision total hip arthroplasty. Seventy patients undergoing total hip revision using a tapered, grid-blasted titanium modular femoral stem were reviewed at a mean follow-up time of 47 months. Femoral defects were classified according to the Pak and Paprosky system, and femoral bone quality was assessed with the Bohm and Bischel system. Clinical function was measured by the Oxford Hip Score. Radiograpic analysis was performed in all cases. Stems were classified as a failure or re-revision in 4.3% of the cases. Three required reoperation for recurrent dislocation, in each case the femoral component alone had been revised during the most recent revision. The postoperative mean Oxford Hip Score was 20.9. Subsidence of the component was noted in 84% of hips but did not cause a significant problem. Final leg length discrepancy was 5.4mm. The results of this titanium, tapered, grid-blasted modular stem compares favourably with other revision stems including the Oxford Hip Score compared to the results for revisions recorded in the National Joint Register (Oxford Score 24.3). Although technically demanding this stem offers a very satisfactory solution for revision of total hips in almost all circumstances

From 1992 on 2008, 615/515 patients underwent primary or revisional endoprosthetic replacement of major joints. In 51 patients (31 men & 20 women) modular system MUTARS (Implantcast, Germany) has been used. The median age was 23.3 years (15 to 52 years). MUTARS modular endoprosthesis has been used in 10 patients with deep infection of endoprosthetic bed as a revisional endoprosthetic replacement: 1 Total endoprosthetic replacement of femur, 5 Total knee joint replacement (2 for distal femoral defect and 3 for proximal tibial defect). In 3(27%) patients, we used newly patented silver ion coated MUTARS either after two stage treatment for infection of endoprosthetic bed or as a prophylaxis of endoprosthetic infection. In 1 patient (23 yrs), with 12cm limb length shortening, we used extensible MUTARS as a revisional endoprosthetic replacement. The following complications we observed: Instability of endoprosthesis – 3/51 (5.9%), deep endoprosthetic bed infection – 4/51 (7.8%). In comparison group, when using custom-made endoprosthesis, the frequency of infectious complications have made 60/574 (10.5 %), and instability of implants was observed in 79/574 (13.8 %) cases. Transition of using modular systems for primary and revisional endoprosthesis allows to reduce the level of instability from 13.8 % to 5.9 %. The quantity of infectious complications is also not great as in comparison with control group. For revisional endoprosthetic replacement, we think, the given modular system is optimal, for correcting limb length deficiency and restoration of basic function at patients. Use of silver ion coated modular implants is a promising method for treating deep endoprosthetic bed infection

The reconstructive hip surgeon is commonly faced with complex cases where severe bone loss makes conventional revision techniques difficult or impossible. This problem is likely to increase in future, as there is a good correlation between the degree of bone loss seen and number of previous total hip operations. In such situations, one alternative is the use impaction allografting with cement. This has captured the attention of the orthopaedic community because of its potential for reconstituting femoral bone stock. The first clinical reports of impaction allografting on the femoral side were in relation to revision with cementless stems. The use of morsellised bone with cement on the femoral side was first reported by the Exeter group. The great enthusiasm with which this technique has been received is related to its biological potential to increase bone stock. The rapid revascularisation, incorporation and remodelling of morsellised compacted cancellous allograft differs dramatically from structural allografting where bone ingrowth usually is limited to 2–3mm. Histological evidence for bony reconstitution has been presented from postmortem retrievals, and from biopsies at the time of trochanteric wire removal. The size of the bone chips used as morsellised allograft is important. The graft behaves as a friable aggregate and its resistance to complex forces depends on grading, normal load and compaction. It is recommended that particles of 3–5mm in diameter make up the bulk of the graft. A bone slurry, such as that produced by blunted bone mills, or by the use of acetabular reamers or high speed burrs would not give satisfactory stability. A wide range of particle sizes is recommended in order to achieve the greatest stability. Future considerations will include the potential for either adding biomaterials to the allograft, or ultimately substituting it completely. A satisfactory cement mantle is required to ensure the longevity of any cemented stem. The primary determinant of cement mantle thickness is the differential between the graft impactors and the final stem. All femoral impaction systems require careful design to achieve a cement mantle that is uninterrupted in its length and adequate in its thickness. The technique of impaction allografting on the femoral side was first and most successfully reported using a highly polished stem with a double tapered geometry and no collar. It is thought to be ideal for this technique as it can subside within the cement mantle, thus generating hoop stresses on the cement which creeps, potentially maintaining physiological loads on the supporting bone. The extension of this technique to other stems has led to some controversy. Confounding factors such as surgical technique, the impaction system available, the type and size of allograft bone used, and the extent of the pre-operative bone loss, will undoubtedly continue to influence such comparisons. It appears that the exact stem configuration may not be as critical as its surface finish, the amount of graft impaction possible and the cement mantle produced. Impaction allografting is the only technique currently available that reverses the loss of bone stock seen in a revision hip arthroplasty. Moreover, this technique does not sacrifice host tissue, and could facilitate further surgery. Impaction allografting, performed with great attention to detail using appropriate equipment, represents an exciting reconstructive solution for contained femoral defects. Its role in larger and combined defects remains open to scrutiny. Careful observation and cautious optimism are necessary as further refinements may well improve the predictability of the clinical results and expand the indications for this important addition to the armamentarium of the revision surgeon

Aims: Prospective multi-center study to evaluate the mid-term results of 280 uncemented femoral stem revisions using the modular MRP-Titan system. Methods: 273 patients with 280 MRP-Titan systems, follow-up for a mean time of 3 years (1 to 8 years). Harris hip score for clinical evaluation, bony defect classification according to Paprosky [163 cases (58%) with type 2B, 2C and 3]. Results: Three aseptic loosenings (1%), three septic loosenings (1%), one additional re-revision because of periprosthetic fracture. Postoperative dislocations occurred in 23 cases (8%), 17 of these (6%) were managed by closed or open reposition without changing the implant. In 6 cases (2%) the antetorsion angle of the modular prosthesis neck was altered. Harris hip score: 38 points preoperatively, 85 points at the last follow-up postoperatively. In 18 cases (6.4%) radiolucient lines were seen, but with no progression and no migration of the stems. The overall survival-rate after 8 years of follow-up was 92%. Conclusions: The modular MRP-Titan system has proven to be valuable in quite problematic cases of hip revision arthroplasty with extensive femoral defects. The system allows intraoperative adaptation of implant length and antetorsion angle to the actual situation, a feature not provided by non-modular femoral revision implants

It has been shown that mesenchymal stem cells (MSCs) and BMP are involved in bone formation. The aim of the study was to evaluate the osteogenic potential of human bone marrow (hBM), human expanded MSC (hexp-MSC), BMP-7, and hexp-MSC plus BMP-7, to treat a rat femoral segmental defect. Sprague-Dawley (SD) and athymic rats (Nu) were used. SD rats where used in order to define surgical technique. Nu rats groups consisted of: G1-autoclaved bone and human bone marrow (hMNC); G2-bone and hexp-MSC; G3-bone with BMP-7 only; and G4-bone and hexp-MSC with BMP-7. A plate was attached to the femoral diaphysis with two cerclage wires. Then a 6-mm femoral gap was made and filled with a different graft. At regular intervals, the femoral defect was evaluated with radiographs, using a modified six-grade Cook classification. At 8 weeks G1 showed non-visible new bone formation; G2 minimal new disorganised bone; G3 disorganised new bone bridging the graft to host at both ends; and G4 significant new bone and graft remodelling. Histological analysis confirmed these results. Our results showed that although the osteogenic activity may be improved by hMSC (G2) as well as by BMP-7 (G3), the association hexp-MSC plus BMP-7(G4) produced graft osteointegration at 8 weeks after surgery. This may have a remarkable impact on future orthopaedics surgery strategies

As the proximal femoral bone is generally compromised in failed hip arthroplasty, achievement of solid fixation with a new component can be technically demanding. Recent studies have demonstrated good short-term clinical results after revision total hip arthroplasty using modular distal fixation stems, but, to our knowledge, none have included clinical follow-up of greater than 5 years. The purpose of this study was to report the clinical and radiographic outcomes assessed 5 to 10 years following revision total hip arthroplasty with a modular tapered distal fixation stem. We retrospectively evaluated 50 revision total hip arthroplasties performed using a modular tapered distal fixation stem Between December 1998 and November 2003. There were 15 men (16 hips) and 34 women (34 hips) with a mean age of 59 years (range, 36 to 80 years). The index operation was the first femoral revision for 46 hips, the second for 3 hips, and the fifth for 1 hip. According to the Paprosky classification, 5 femoral defects were Type II, 31 were Type IIIA, and 14 were Type IIIB. An extended trochanteric osteotomy was carried out in 24 (48%) of the 50 hips. Patients were followed both clinically and radiographically for a mean of 7.2 years. The mean Harris hip score improved from 54 points preoperatively to 94 points at the time of the latest follow-up. The mean stem subsidence was 1.5mm. Three stems subsided more than 5 mm, but all have stabilized in their new positions. During follow-up, a total of 4 hips required additional surgery. One hip had two-stage re-revision due to deep infection, one had liner and head exchange for alumina ceramic head fracture, and the other two underwent isolated cup re-revision because of aseptic cup loosening and recurrent dislocation, respectively. No repeat revision was performed due to aseptic loosening of the femoral component. Complications included 6% intraoperative fractures, 4% cortical perforations, and 4% dislocations. There were no stem fractures at the modular junction. The medium-term clinical results and mechanical stability obtained with this modular tapered distal fixation stem were excellent in these challenging revision situations with femoral bone defects

Over the last 10 years ACI (Autologous Chondrocyte Implantation) has become an important surgical technique for treating large cartilage defects. The original method has been improved by using cell seeded scaffolds for implantation. The aim of our prospective study was to evaluate the efficiency of a matrix based ACI (MACI) with a collagen type I scaffold for repairing large cartilage defects of the knee. We present the clinical and radiological results of 22 pts. one year after collagen scaffold based ACI. Out of 39 pts. treated with ACI for cartilage defects of the knee 22 had reached the one year follow up. We documented preoperatively and postoperatively (3, 6 and 12 months) the clinical situation with the IKDC Knee Examination Form. MRI scans were evaluated at all time points. 41% of the pts. were female, 59% male. The average age was 33 yrs. (min:15; max:49), the average BMI 25,4 (min:19; max:36). One third of the cartilage defects were localized retropatellar, the remaining on the medial or lateral femoral condyle. The average defect size was 5.7 cm2. In about 75% of the cases an additional surgical procedure was performed (ACL-reconstruction, lateral release, meniscal surgery). One major complication (a deep wound infection) occured. The IKDC score improved over time during follow up significantly. Patients with retropatellar defects have a poorer outcome compared to femoral defects. The MRI showed an improvement of the implanted scaffold over time as well. The present study confirms the benefits of MACI in young patients with large cartilage defects of the knee. The matrix based ACI is a surgically less demanding technique then the traditional ACI. We expect a good long term outcome from MACI comparable to that of traditional ACI

Introduction: Impaction allografting is an established method for restoring deficient bone during revision arthroplasty of the hip. Graft augmentation with synthetic materials has been proposed and evaluated experimentally. Our aim was to assess clinically whether migration and wear of implants with a synthetic graft mix would be equivalent to pure allograft. Materials and Methods: Patient inclusion criteria were: acetabular and or femoral defects from aseptically loosened primary THR undergoing cemented revision with impaction grafting; age 55–80 years; initial diagnosis of osteo arthritis; good health with reasonable daily activity level. Patients were randomized to receive either pure allograft or a 50% mixture with a porous hydroxyapatite material (Apapore60, Apatech, UK). Revision was with the Exeter stem, antibiotic Simplex cement (Stryker Howmedica Ltd), and Ogee cup (Depuy Int. Ltd., Leeds, UK). Tantalum markers were inserted into the pelvis, cup, femur, cement and graft in order to measure migration with radiostereometry (RSA). Patients received a sequence of RSA examinations up to 2 years. A total of 26 patients (18 for the femur) have been analysed. Results: At 2 years no significant differences were seen in cup wear, or migration of the cup, femoral and pelvic graft markers. Stem migration occurred mainly at the stem cement interface. The rate of distal migration for the femoral head was greater for pure allograft in the first year (p < 0.05), however this rate reduced significantly in year two. Higher medial migration in year one was observed for the proximal medial cement mantle for allograft (p < 0.05). Conclusions: Improved stability and normal cup wear were observed in a randomized clinical study for a synthetically augmented allograft. This agrees with experimental findings. 1. Longer follow up with increased patient numbers is recommended to confirm these findings

Purpose: The aim of this study is the mid-term analysis of osteochondral autograft transplantation for the repair of focal femoral defects. Methods: We present clinical data based on arthroscopic and MRI appearances of 18 patients, from 2 to 6 years postoperatively, which illustrate growing concern about the progressive deterioration of articular cartilage surrounding the OAT graft. It seems that the osteochondral autograft transfer (OAT) can restore the height and the shape of articulating surface in osteochondral defects with composite autologous material that contains hyaline articular cartilage and a firm carrier. However, limited availability of autologous osteochondral grafts, dead spaces between circular grafts, the lack of integration of donor and recipient hyaline cartilage, and different thickness and mechanical properties of donor and recipient hyaline cartilage are frequent sources of clinical concern. Results: Typically, the OAT graft itself maintains its mechanical and histological integrity over the years, but surrounding articular cartilage continues to deteriorate, leading to a wide area of further chondral damage. Although this is difficult to understand and explain, it seems that the damage to articular cartilage surrounding the defect, and probably most importantly the lack of chondral integration, are the main reason for further chondral damage. Conclusion: Adherence to clear indications, correction of concomitant pathology, precise surgical technique and realistic goals are most important when considering OAT surgery in symptomatic patients with femoral osteochondral lesions. Treatment of focal femoral chondral lesions in active individuals remains a significant challenge with many controversies remaining

Objective: Clinical and radiological comparison of unconstrained and constrained knee endoprostheses in revision total knee arthroplasty after septic or aseptic loosening in consideration of quality of life, activity and patella related problems. Material and methods: 26 patients with 10 hinge pros-theses and 16 condylar prostheses were examined using the following scores: HSS, Knee Society Score, Visual Analogueue Scale, Tegner Activity Score, Patella Score, SF-36-helth questionaire. Before implantation all hinge endoprostheses were septic and all condylar endopros-theses aseptic. For radiological examination the Knee Society and Engh Score were used. Results: There were no significant deviations in clinical parameters between the types of prostheses resp. septic or aseptic history. Radiological parameters deviated significantly in only one parameter: the femoral defects in hinge prostheses were significantly larger (p=0.0036). Regarding at patients with hinge prostheses compared with healthy subjects of the same age deviated significantly only in limitations in physical activities because of health problems, limitations in usual role activities because of physical health problems and bodily pain. In the group of condy-lar endoprostheses there were significant deviations for all items except vitality and general mental health. Conclusion: The choice of condylar or hinged endopros-theses does not have any significant influence on clinical results, neither has aseptic or septic history. The quality of life results of condylar prostheses were inferior

Introduction: The Wagner SL Stem is a well established implant to bridge proximal femoral defects in hip revision surgery. The tapered shape offers the possibility of press-fit anchorage distal to the bone defect. There are missing long term results with absolute follow-up over ten years. The goal of the study was to observe the subsidence and the restoration of the proximal bony stock within ten years. Patients and Methods: From 1988 until 2005 198 Wagner Stems were implanted in our hospital. 50% of the indications were due to aseptic loosening, 25 % due to septic loosening and 10% due to periprosthetic fracture and 15% other indications. Clinical function was measured with an adapted Harris Hip Score; subsidence was measured in the way that was previously described by Callaghan. The bony restoration was controlled with Böhm’s technique. The length and the thickness of the area of integration were measured in mm on the ap radiographs of the femur. Results: The over all survival of the 198 Wagner stems after 17 years was 87%, for aseptic loosening. There were 57 implanted stems with ≥10 years follow-up. 31 of the patients died before the ten year control, four stems had to be exchanged because of aseptic loosening, three patients referred the clinical control so that a total number of 19 stems could be followed for at least 10 years. In two of those 19 stems there was significant subsidence (12 and 33mm), the subsidence occurred within the first year after implantation. The area of integration showed no change of length or thickness. The bony restoration was good or excellent in 70%. The adapted Harris Hip Score declined only little from 80 postoperatively to 75 after ten years. Conclusion: No significant subsidence after Osteointegration occurred. The principle of the tapered stem is as good that the Wagner SL Stem can be widely indicated

The use of monoblock tapered stems has shown very good results in hip revision surgery, particularly in case of severe proximal femur bone deficiency. However a too valgus neck, a short offset, may result in a high risk of dislocation. In addiction monoblock stems make the control of limb length difficult, and potentially increase the risk of subsidence or intraoperative fracture. Different types of modular tapered stems with distal fixation have been developed to allow a more user-friendly restoration of limb-lenght discrepancy and an indipendent proximal control of offset and anti-retroversion. We assessed 64 hip revisions performed on 63 patients (mean age 62 years). Indication for treatment was: aseptic loosening (42 cases) septic loosening (18 cases) and periprosthetic fracture (4 cases). According to Paprosky classification, femoral defects were staged as type I (2 cases), type II (20 cases), type IIIA (25 cases) and type IIIB (13 cases); periprosthetic fractures were all type B2 according to the Vancouver classification. In all cases we used a Restoration® Modular (Striker, Orthopaedics) cone-conical uncemented stem implanted by a lateral approach, with a trans-femoral osteotomy in 19 cases. A preventive cerclage cable was used in 10 patients in case of very thin cortex. We used the minimum size stem in most of the cases. Mean follow-up was 20 months (range 6–36). Short-term complications included hip dislocation (1 case), recurrent infection (1 case), stem subsidence > 5 mm (1 case). Mean Harris Hip Score improved from 43 to 81.9 (t test p< 0.0005), while limb lenght discrepancy improved in 97% of cases with symmetry in 76%. The use of modular revision stems is an effective alternative in hip revision surgery that ensures good primary stability, while modularity enables the implant to be tailored to the patient, allowing restoration of the limb length and correct muscular balancing

Bone Loss is the main problem in failed total hip arthroplasties. Revision surgery must be conformed to the degree of the bone loss. Since 1986, 330 cases of failed THA underwent to revision surgery. Different solutions were adopted according to Paprosky femoral defects classification. In type I, a primary cementless stem was implanted (23%). In type II and IIIa, were proximal fixation is still possible to achieve, Mid PCA-Howmedica (5%) and modular S-ROM-J& J revision stems (18%) were implanted. In all the other degree of bone loss (IIIb–IV) cementless distal fixation stems, Long PCA-Howmedica (17 %), Wagner-Sulzer (18 %) and modular (MP-Link, Profemur-Wright) (19 %), were used. Patients were clinically and radiographically evaluated by HHS and according to Engh’s criteria. Best results were observed in Type I group (HHS=90). Long and mid PCA stems presented poor clinical (HHS=60) and radiographical results and required re-revision in 15% of cases. Intermediate results were observed in Wagner prostheses. Modular revision stems showed best results although earlier F-U. (HHS=80). Of these, re-revision surgery was performed in two cases, one of which because of infection and the other one due to severe thigh pain. Cementless modular stems seem to be the most suitable technique. Distal fixation associated with proximal fill permit to manage the majority of femoral bone defects minimizing bone grafts. The modular stems, allow to conform the design of the components to the bone defects permitting to achieve primary stability (press-fit), restoring the centre of rotation and muscles tension, reducing pain and restoring hip function

Introduction: The increasing utilization of total hip arthroplasty and the increasing life expectancy have brought an increasing incidence of revision hip arthroplasty. With severe acetabular, revision surgery with the use of standard cemented or press-fitted components is inadequate for fixation. In these cases the use of proximal femoral allograft can restore the deficiency. Purpose: To present a new technique and preliminary results of revision total hip arthroplasty using proximal femoral allograft prosthetic composites for massive ace-tabular bone loss. The technique uses the natural vector of forces in the intertrochanteric region in an opposite direction at the acetabular defect. Methods: From June 2000 to July 2001, seven patients underwent reconstruction of massive acetabular defects with proximal femoral allograft bone. The etiologies for bone loss were infection in 2 patients, aseptic loosening in 4 and acetabular protrusion in 2 patients. In 4 hips there were also femoral defects that was reconstructed with allograft. The average age of the patients was 69.8 years. All patients were wheel chair bound prior to surgery. Harris Hip Score was used to assess preoperative and follow-up function level. Results: Harris Hip Score improved significantly in all patients. All patients are ambulatory at follow-up. Complications included 2 dislocation and 2 deep-vein thrombosis. No allograft resorbtion was noted at follow-up. Conclusions: The proximal femoral allograft provides a solid construct for the acetabular cup in large acetabular bone defects. Although failure and complication rates might be higher than revision procedures with lesser bone defects, this reconstructive option for massive ace-tabular defects dramatically improves a patient’s function level

Introduction: Transplantation of autologous chondrocites offers promising results. A new technique is now gaining ground which uses a “scaffolding” of hyaluronic acid (Hyalograft C©, Fidia, Italy). Materials and methods: Thirty-five patients have been treated with Hyalograft C© since 2000. 31 were operated on for a knee and 4 for an ankle. Clinical progression was documented both preoperatively and postoperatively by means of a clinical protocol (VAS-Scale, Lysholm, ICRS, IKDC; AOFAS, Cincinnati). Twenty-one patients with knee lesions (11 had particular circumscribed defects, 7 had complex lesions and/or related lesions, 3 patients were given this indication as a last resort in an effort to avoid the use of a prosthesis) and 4 with ankle lesions were followed up for over 6 months postop. Results: Assessment by means of the VAS-Scale showed a reduction in pain. In addition, it was possible to show an improvement in function ranging from 51 points pre-op to 75 points post-op on the Lysholm Score. In patients with particular lesions an improvement of 57 to 97 points was achieved. All of the 3 patients where the indication was used as a last resort received a prosthesis. In ankles, the improvement ranged between 2,5 to 6.3 points on the modified Cincinnati-Score. Conclusions: In the case of the classical indication for isolated femoral defects, the results obtained with Hyalograft C© show similar results to I.C.A. In complex lesions, results were considerably worse. Osteoarthritis has shown itself not to be an indication for this technique. On the other hand, the use of Hyalograft C© makes it possible to perform transplants with a smaller surgical incision as well as to fill defects without resorting to sutures

Introduction: This study compared the accuracy of reduction of intra-medullary nailed femoral shaft fractures, comparing conventional and computer navigation techniques. Methods: Twenty femoral shaft fractures were created in human cadavers, with segmental defects ranging from 9–53mm in length. All fractures were fixed with antegrade 9mm diameter femoral nails on a radiolucent operating table. Five fractures (control) were fixed with conventional techniques. Fifteen fractures (study) were fixed with computer navigation, using fluoroscopic images of the normal femur to correct for length and rotation. The surgeon was blinded to defect size. Two landmark protocols were used in the study group referencing the piriform fossa (Group A, n=10) or proximal shaft axis (Group B, n=5). Postoperative CT scans, blindly reported by a musculoskeletal radiologist, were used to compare femoral length and rotation with the normal leg. Results were analysed using ANOVA with 95% Confidence Intervals. Results: The control and study groups were not statistically different with respect to age of cadaver or size of femoral defect. Results: The mean leg length discrepancy in the study groups were significantly less (3.6mm (95% CI 1.072 – 6.128) and 4.2mm (95% CI 0.63–7.75), compared with 9.8mm (95% CI 6.225 – 13.37) in the control group (p< 0.023). The mean torsional deformities in the study groups were 8.7 degrees (95% CI 4.282 – 13.12) and 5.6 degrees (95% CI -0.65 – 11.85), compared with 9 degrees (95% CI 2.752 – 15.25) in the control group (p=0.650). Within the navigated study group, length discrepancy was similar in subgroups 1 (3.6mm) and 2 (4.2mm). Torsion appeared more accurate in group 2 (5.6 degrees) than group 1 (8.7 degrees), although this was not statistically significant. Discussion: Computer navigation significantly improves the accuracy of femoral shaft fracture fixation with regard to length. With further modifications to improve reduction of rotational deformity, it may be a useful technique in the treatment of femoral fractures

Introduction and Objectives: Severe proximal femoral defects are a major problem in femoral stem revision surgery. Various surgical techniques have been described that aim to resolve the deficit of bone stock: the Exeter technique or impacted allograft bone, long porous surface distal fitting stems, stems coated with hydroxyapa-tite, and modular stems with metaphyseal fixation. In 1987, Wagner presented a revision technique using a long distal fitting conical stem with excellent proximal bone regeneration. However, the Wagner stem presents two fundamental problems: subsidence and dislocation. Furthermore, it is a demanding technique that requires preoperative planning. Conical fixation makes adjustment of length and anteversion more difficult, as it is dif-ficult to change these parameters after impaction. Materials and Methods: This is a retrospective study of the first 86 Wagner prostheses implanted at our centre. Results: The reason for revision was aseptic loosening in 81.8% of cases. A morselised bone graft was used in the femur in 22% of cases. Average follow-up period was 6.5 years. Complications occurred in 33% of cases. Half of these complications were perioperative fractures of the femur, which for the most part required no additional treatment besides intervention during the operation. Of the 6.8% of implants that were loose, only 3 cases required surgical treatment. Subsidence occurred in 40.9% of implants, with a median of 13.5mm. Of the 40.9% of implants that sank, two-thirds sank more than 0.5cm. Average metal-bone contact was 27.57mm postoperatively, 39.9mm at one year postoperatively, and 50.38mm at final evaluation. Discussion and Conclusions: The Wagner prosthesis has yielded good results in revisions with proximal bone defects. However, it presents a high rate of dislocation and subsidence, in relation to the technical demands of the procedure

Callus distraction over an intramedullary nail is a rarely used technique for the reconstruction of intercalary defects of the femur and tibia after radical debridement of chronic osteomyelitic foci. The aim of this study was to summarize our experience of distraction osteogenesis with an external fixator combined with an intramedullary nail for the treatment of bone defects and limb shortening produced as a result of radical debridement of chronic osteomyelitis. Sixteen patients aged 16 to 63 years underwent radical debridement to treat nonunion associated with chronic osteomyelitis of 8 tibias and 8 femurs. The lesions were staged as Cierny and Mader type IVA (10) and IVB (6). The resulting segmental defects and any limb length discrepancy were then reconstructed by distraction osteogenesis over an intramedullary nail. A monolateral frame was used for the femur, and a ring type external fixator for the tibia. Two patients required local gastrocnemius flaps. Free non-vascularised fibula grafts were added to the regenerate for augmentation of a femoral defect at the time of external fixator removal and locking of the nail. At the latest follow-up, functional and radiographic results were evaluated using the Paley’s criteria. In the femur, the mean defect was 10 centimeters (range 6 to 13 centimeters), while in the tibia it was 8.4 centimeters (range 5 to 11 centimeters). The mean external fixator index was 13.5 days per centimeter, the consolidation index was 36 days per centimeter and the mean time to union at the docking site was 9 (range 5–16) months. The average follow-up was 31.3 months. We obtained 81.25% (13 of 16) excellent results in terms of both bone and functional assessment. There were two recurrences of infection necessitating nail removal. These patients underwent revision with an Ilizarov fixator. Subsequently, infection was controlled and the non-unions healed. This combined method may prove to be an improvement on the classic techniques for the treatment of long bone nonunions associated with chronic osteomyelitis, in terms of external fixation period and consolidation index. These appears to be no increase in the risk of complications, and the earlier removal of the external fixator is associated with patient comfort, decreases the complication rate and facilitates convenient and quick rehabilitation

Introduction: Chronic hip arthroplasty infection is a difficult situation to solve. The use of uncemented stem is questionable, as no antibiotic loaded cement is used to fix the implant. Bone deficiencies are often enlarged by the chronic infection process and the multiple previous surgeries. We report our experience in two stage revisions with massive allograft and uncemented distal locked stem. Material and method: We have retrospectively reviewed 15 patients operated on from chronic hip arthroplasty infection and secondary large femoral defects. Two stages revision with a temporarily antibiotic loaded cement spacer and 6-weeks second look reconstruction were performed with massive proximal femoral allograft and a long distally locked stem. The uncemented stem was cemented into the allograft and remained uncemented in the recipient distal femur. Outcome was assessed regarding infection control, allograft complication and function according to the Merle d’Aubigné score. Results: Patients mean age was 62 years (SD 11). Patients were already operated from the same hip 5.9 +/− 2.3 times before the actual procedure. Isolated microorganisms were MRSE (7), staph Aureus (4), MRSA (1), VRE (1), enterococcus (2). Muscle flaps were performed in 2 cases and discuss for 2 more. Allograft length was 22 +/− 9 cm. Antibiotic treatment was maintained for 4.6 +/− 2.5 months (median 3 months). Mean follow-up was 29 months (SD 26; median 23). Clinical outcome based on Merle d’Aubigné score is 5.3 +/− 3 before treatment and 13.8 +/− 2.5 at the last visit. Complications were registered in 4 cases. Infection recurrence was observed in 3 cases (2,7,20 months) but the function was preserved in all cases. One of them needed a two stage procedure with a new allograft after 19 months due to acute staph Aureus infection. One allograft was broken after 80 months and need one stage revision. Discussion: While the treatment of these cases was particularly demanding as bone deficiencies and microorganisms antibiotic resistance were high, functional result obtained was good. When infection recurrence was observed, function remains preserved. The use of uncemented distal locked stem with a cemented massive allograft did not lead to mechanical or hardware problem and allow us to restore the bone stock and the gluteus tendons insertion. The use of a modular stem was very helpful in solving these complex situations. Massive allografts can be used in case of infection as antibiotic delivery system

In revision hip Arthroplasty, there often exists the intact femoral cortex under the level of loosened stem. In such cases we used a mid-length full-porous Cementless stem, because femoral bone remodeling and reinforcement could be obtained. We evaluated the readiographical change in femur after the inplantation of full-porous Cementless stem. Materials and methods: Thirteen revision hip Arthroplasties with the use of mid-length full-porous Cementless stem (Ostenics Specilty Stem) were evaluated. Before revision operation, aseptic loosening and sinking of femoral stem were seen in all hips. In three hips, varus shift of femoral component was seen, and in one hip, anterior shift was seen. Bone graft was done only around the proximal femoral defect. No bone graft was done at the level of middle and distal bone defect of the femur. The average age at revision operation was 59 (43-75) years old. Average follow up was 32 (15-59) months. All hip were evaluated clinically and radiographically, especially about the femoral cortical bone remodellig after operation. Results: Ten patients were pain free, and three had thigh pain. Subsidence of the stem occurred in one patient who complained of thigh pain. In this patient, cortical enlargement and thinning of femur was extreme before operation. Other 12 cases have no subsidence of the stem. Ten patients had a satisfactory result in clinically and radiographically. In six patients, who had bone defect of middle and distal femur before operation, the new bone formation between stem and the cortex of the femur was seen at the latest follow up. Femoral bone remodeling was optained in the middle and distal femur without bone graft. Conclusion: Revision hip Arthroplasty with the use of full porous Cementless stem is a useful option because femoral bone remodeling and reinforcement can be obtained

Purpose of the study: Epithelioid hemangioendothelioma is considered to be a low-grade malignant sarcoma. Surgical treatment is indicated. The multifocal form of the disease is always located on the right side, involving either a limb or the half-body. Based on a case report and a review of the literature, we discuss the nature of this tumor which may or may not be malignant and examine possible indications for non-mutilating surgery. Case report: A 17-year-old female consulted in 1996 for lytic lesions involving the right lower limb. Most of the lesions were located on the lower portion of the femoral metaphysic and the upper tibia. The lesions appeared as lytic defects with minimal fracture-like lines on the rims. There was also a defect in the lower tibia shaft and in the foot. All lesions involved the right lower limb. Biopsy material obtained in July 1996 confirmed the diagnosis of grade I epithelioid hemangioendothelioma. Search for skeletal and visceral extension was negative. The classical treatment described in the literature is disarticulation of the hip. Considering the static presentation of the lesions, a conservative treatment was attempted. On July 17, 1996, the patient underwent surgery for curettage, liquid nitrogen cyrotherapy, and cement filling of the tibial and lower femoral defects where there was a risk of fracture. The other lesions were not treated. In 1999, the lesion located in the toe became painful and was treated by cement filling. The patient was discharged with simple surveillance. In 2005, i.e. 102 months after cement filling, this young patient was continuing her university education. No new lesion had developed. All lesions remained stable or regressed, including those which had not been treated. Discussion: Multifocal epithelioid hemangioendothelioma is generally considered as a sarcoma. Careful examination of the literature (less than 50 cases published) shows many discordant elements. First, the lesions are always hemimelic on the right side, never described on the left, an unusual situation for a malignant process. In addition, the clinical courses described to not lead to death by metastasis. The only progression reported involves possible growth of known lesions. The malignant nature of this disease is thus questionable, even though the histological aspect is exactly the same as monofocal epithelioid hemangioendothelioma which can have a much more aggressive, clearly malignant, course. Conclusion: Surgeons must not propose first-intention amputation for multifocal epithelioid hemangioendothelioma. Because of the favorable outcome observed in our patient warrants, the malignant nature of this condition is questionable

Our centre has used a specially designed custom-made endoprostheses with curved stems to reconstruct femoral defects in patients with residual short proximal femur after excision of primary bone sarcoma over the last 18 years. Two designs of endoprostheses with curved intramedullary stems were used: the rhinohorn stem type and the bifid stem type. We report the safety, survival and functional outcome of this form of reconstruction. Twenty six patients who had these special endoprosthesis reconstruction were studied. The median age was 16 years (range 7 to 60 years). Prostheses with rhino horn stems were used in 15 patients and bifid-stem in 1 1 patients. Twenty patients had the prostheses inserted as a primary procedure after excision of primary bone sarcoma, and in six patients the prostheses were inserted after revision surgery of failed distal femur endoprostheses. Seventeen patients (65%) were alive and free of disease at a median follow-up of 98 months (12 to 203 months) and nine patients had died of metastatic disease. Local recurrence developed in two patients (1 0%) out of the 20 patients. Surgical complications occurred in five patients (191/o). Deep infections occurred in two patients (8%) requiring revision surgery in one patient. Prosthetic failure, occurred in nine patients (35%). The cumulative survival of prostheses was 69% at five years and 43% at 10 years. Musculoskeletal Tumour Society mean functional score was 83% (53% to 97%). In conclusion, preservation of a short segment of the proximal femur and the use of endoprostheses with curved stems for reconstruction of the femur is technically possible. There is an increased risk of fracture of the prostheses decreasing the survival rate. Functional outcome of patients with this form of reconstruction is not significantly different from the functional outcome of patients who have proximal femur or total femur endoprosthetic reconstruction. This operation is particularly desirable in skeletally immature patients and allows normal development of the acetabulum

Bone impaction grafting (BIG) is a surgical technique for the restoration of bone stock loss with impaction of autograft or allograft bone particles (BoP). The goal of a series in-vitro and in-vivo experiments was to assess the suitability of deformable pure Ti (titanium) particles (TiP, FONDEL MEDICAL BV, Rotterdam, The Netherlands) for application as a full bone graft substitute in cemented revision total hip arthroplasty. TiP are highly porous (interconnective porosity before impaction 85 to 90%). In-vitro acetabular reconstructions were made in Sawbones (SAWBONES EUROPE, Malmö, Sweden) to evaluate migration by roentgen stereo photogrammetric analysis and shear force resistance by a lever out experiment. In-vitro femoral TiP reconstructions (SAWBONES, Malmö, Sweden) were used to evaluate micro-particle release and subsidence. Mature Dutch milk goats were used for two in-vivo experiments. A non-loaded femoral defect model was used to compare osteoconduction of bioceramic coated TiP with BoP and ceramic particles (CeP). Acetabular defects (AAOS type 3) were reconstructed in 10 goats using a metal mesh with impacted TiP acting as a full bone graft substitute in combination with a cemented polyethylene cup and a downsized cemented Exeter femoral stem (STRYKER BENOIST, Girard, France). Blood samples were taken for toxicological analysis. In-vitro: TiP were as deformable as BoP and created an entangled graft layer (porosity after impaction 70 to 75%). Acetabular TiP reconstructions were more stable and resistant to subsidence and shear force than BoP reconstructions (lever-out moment 56 ± 12 Nm respectively 12 ± 4 Nm, p < 0.001). After initial setting, femoral subsidence rates were smaller than seen in femoral bone impaction grafting (0.45 ± 0.04 mm after 300 000 loading cycles). Impaction generated 1.3 mg particles/g TiP (particle Ø 0.7–2 000 μm, tri-modal size distribution). In-vivo: Bioceramic coated (10 −40 μm) TiP showed bone ingrowth rates comparable to BoP and CeP. Reconstructed acetabular defects showed rapid bone ingrowth into the layer of TiP. Serum titanium concentrations slowly increased from 0.60 ± 0.28 parts per billion (ppb) preoperatively to 1.06 ± 0.70 ppb at fifteen weeks postoperatively (p = 0.04). Mechanical studies showed very good initial mechanical properties of TiP reconstructed defects. The in-vitro study showed micro-particle generation, but in the short-term goat studies, histology showed very few particles and no negative biological effects were found. The in-vivo acetabular study showed very favorable bone ingrowth characteristics into the TiP layer and a much thinner interface with the cement layer compared to similar defects reconstructed with BoP or mixtures of BoP with CeP. Further analysis in a human pilot study should proof that TiP is an attractive and safe alternative for allograft bone in impaction grafting revision arthroplasty

Purpose: After cementing, various changes are observed in femoral bone resulting from various factors (ageing process, stress forces, granuloma…). The purpose of this work was to examine the radiological expression of these changes a mean 12 years after prosthesis implantation. Material and methods: Charnley-Kerboull total hip arthroplasty was performed in 304 patients (338 hips) between January 1st, 1984 and December 31st, 1986. Mean age of the population was 65.5 years. Most of the patients had degenerative hip disease (81.4%). Among these 304 patients, 108 had died and 56 were lost to follow-up, giving 174 patients retained for analysis at a maximum follow-up of 16 years (mean 12 years). Noble and Nordin scores were recorded before surgery and during follow-up as were the cortical and cement thicknesses in the seven zones described by Gruen. Results: The actuarial curve, calculated for the 338 hips showed 95.1% survival at 12 years (taking into account all revisions irrespective of the cause). Femoral stem survival was 97.1±2% taking certain or probable loosening as the endpoint. Several categories or radiological changes were observed: – femoral defects (18%) correlated with cup wear; – progressive widening of the medullary canal without loosening and a mean femoral score moving from 55.7 to 52.16 (p< 0.01) especially in thin women and for wide-mouthed femurs; – cortical thickening near the tip (57%) more frequently for greater distal filling; – stress shielding especially in women (p< 0.001) with a low initial score for the femur (p< 0.0006) and with greater distal filling. Conclusion: Like Kerboull, we tried to achieve primary stem stability before cementing. Cementing results were good (97% at 12 years), but detailed radiographic analysis demonstrated that cortical thinning remained in zone 7, especially when the primary stability was achieved in the distal portion of the femur (high preoperative Noble index). Variations in the metaphyseal-diaphyseal ratio require adaptating the form of the stem to be cemented in order to achieve better filling and avoid primary stability mainly in the distal portion

Introduction and Objectives: The purpose of this study is to analyse the clinical and radiographic results of revision total hip prosthesis using femoral stems with diaph-yseal fixation. Materials and Methods: We assessed failure of the primary prosthesis based on Paprosky’s classification to identify the femoral defect and determine the optimal component for revision, keeping in mind the difficulty of classifying bone defects based on radiographic parameters. The most commonly-used replacement models were KAR revision stems (wide, straight, long necks and hydroxyapatite-coated along the entire length) and Restoration-T3 stems (diaphyseal fixation, modular, fits different necks, Wagner model progression, particularly indicated to facilitate extraction of cement using a buried diaphyseal osteotomy). Clinical evaluation was done using the Merle D’Aubigné and Postel scales modified by Charnley. Radiographic evaluation of prosthetic stability and osseointegration was done using Engh’s criteria, checking for presence or absence of radiolucency, migration, pedestal, and increase or decrease of endosteal and periprosthetic density (calcar, diaphysis, and greater trochanter). Results: We examined 47 KAR stems and 16 Restoration-T3 stems, with an average follow-up period of 4.1 years (range: 1–9 years) and an average patient age of 69.4 years (range: 40–79 years). Of these, 6 were Paprosky type 1, 36 were type II, 14 were type IIIA, 5 were type IIIB, and 2 were type IV. Average preoperative clinical score was 9.76 points. Aetiology in all cases was aseptic loosening of a primary prosthesis, with the exception of one case of a delayed Corynebacterium infection. There were 2 partial Monk prosthesis revisions and 3 periprosthetic fractures. Average postoperative clinical score was 15.83 points. There were no deep infections or dislocations. Radiolucency was noted in only one case, and no migrations of more than 2 mm were seen. No further stem revisions were required in this series, though we believe a future revision will be necessary in at least one case. Discussion and Conclusions: The use of femoral stems with diaphyseal fixation is an acceptable alternative in revision surgery of the hip, even in cases of major bone deficit. Modular stems have the added advantage of versatility to adapt to a great variety of prosthetic salvage procedures

Introduction: Revision in total hip arthroplasty (THA) continues to be a technical challenge because of difficulties in fixation of the femoral component in mostly deficient bone in the proximal femur. In the past, the use of primary stems in revision surgery has also been described by many authors. Very often, the cortical bone is not sufficient enough for torsional or axial load bearing. In this retrospective study we present our clinical results of femoral component revision surgery using the uncemented primary BiCONTACT stem (Aesculap). Methods: In this study, seventy-nine patients were examined who underwent a revision of the femoral component in total hip arthroplasty (THA) with the uncemented primary BiCONTACT stem between December 1991 and April 2004 (mean follow-up 6.8+/−3.9 years). Only patient with a defect classification of Paprosky I–II were analysed. The average patient age was 67.1+/−10.1 years (range from 34–87 years). Forty-six female and thirty-three male patients (168+/−10 cm mean height, 75+/−12 kg mean weight, mean Body Mass Index: 26.4+/−2.5) were included in the study. All patients were clinically evaluated both preoperatively and postoperatively using the Harris Hip Score (HHS), a pain score (from 0 [no pain], to 10 [max. pain]) and a motion score (from 0 to [no flexion], to 10 [max. flexion]). Furthermore, the radiographs (anteroposterior and axial) before, after surgery and at follow-up were analysed concerning femoral defects, proximal bone loss, and to determine the quality of bony fixation. The defects were classified using the Paprosky classification. For statistical analysis, the paired Student t-test was used for preoperative and postoperative data. Results: The postoperative Harris Hip Score (78.9+/−12.5, p < 0.001), Range of Motion Score (p < 0.05) and Pain Score (p =0.005) improved significantly. During follow-up there were only four re-revisions within two years after revision surgery: two re-infections in the first year, two aseptic loosening in the second year. There were only two cases of mild stress shielding. The survival curve (Kaplan-Meyer) showed a 10-years survival rate of 96.2 %. In two cases we found intraoperative periprosthetic fractures and in fourteen cases small fissures during removal or implantation of the stem. Discussion: The primary uncemented BiCONTACT stem appears to be a good alternative to other revision systems in well-selected femoral revision cases with minor defects. The results of this study correspond to those published before, using a primary cementless stem in cases of revision. Therefore, in cases of minor proximal and metaphyseal bone defects (Paprosky I–II) the use of a primary stem in femoral revision should be considered. However, an exact preoperative planning, intraoperative assessment of bone stock, and experienced surgeon is necessary

Femoral revision total hip arthroplasty is a technically demanding procedure, especially when there is extensive proximal femoral bone loss. Secure fixation maynot be possible to achieve if the implant relies solely on proximal metaphyseal fit. The use of a long tapered cementless stem having a microporous surface offers a strong anchorage distal to the damaged bony segment. By bypassing the compramised proximal femur, initial implant stability is achieved and a high rate of osseointegration can be expected. We present our experience with Link MP reconstruction stem which utilises distal fixation and has a modular proximal end.. The prosthesis is made of Tilastan( Ti6AI4V Eli Titanium Alloy) with microporous texture of about 70 microns pore diameter. The distally tapered stem is angled about 3 degrees proximally to enable easy insertion of the stem. In our series there were 53 stem revisions done in 51 patients. Twenty three were males and 28 were female patients. The average age of the male patient was 66 years and that of the female was 74 years. The mean followup was 37 months( range 12–76 months.) Indications for revision were aseptic loosening in 35 cases, infected hip replacements in 8 patients and periprosthetic fracture in ten cases. Revision for infected primary arthroplasty was done in two stages with the Link MP stem inserted at the second stage. All the proximal femoral defects were classified radiographically as described by Gustillo and Pasternak. There were 29 type 2 defects and 14 type 3 defects. The periprosthetic fractures were classified as per the Vancouver system and all the cases were type b fractures. Clinical scoring as described by d’Aubigne and Postel was used . The mean preoperative score was 3.5 while average score at the time of follow-up was 9.8. The subsidence ranged from none to 6mm. Good radiological evidence of proximal femoral restoration was seen in 44% of the cases in our series. Complications included greater trochanter fracture in 4 cases, perforation of the anterior cortex during reaming using the rasp in 2 cases and dislocation in one patient. In one case there was unacceptable penetration of the implant medially and this was subsequently treated by re-revision with a Huckstep stem. There were two intraoperative fractures which were treated with circlage wire fixation and they went on to union. None of the patients required a re-revision till date. In conclusion , our experience with Link MP reconstruction stem has been encouraging as shown by the improved d’Aubigne & Postel scores and low rate of complications. We also observed proximal femoral restoration and high implant survivorship in our series

Purpose: Revision surgery for total hip arthroplasty (THA) is frequent and defect filling has become a daily problem. Morbidity and insufficient graft supply complicate the problem. Worry about the long-term outcome of certain allografts together with the nearly complete disappearance of xenografts has led to wide development of the use of synthetic ceramic materials. Material and methods: We have used two biphasic calcium phosphate (BCP) synthetic ceramics for revision THA since October 1996. The first is supplied in quadrangular granules measuring a few mm on a side. It is composed of 55% hydroxyapatite (HA) and 45% tri-calcium phosphate (TCP). It presents pores of approximately 400 microns in diameter, total porosity, total interconnection of 60%. It is indicated for filling bony defects. The second BCP is composed of 65% HA and 35% TCP with smaller pores (200 mm) and a non-totally interconnected porosity so the compression resistance is 20–30 MPa. This material is indicated for mechanical support more than filling. Sixty-six femurs and 75 acetabula were reconstructed with these materials and reviewed at three to seven years. Granules were used alone for cavitary bone defects, both for acetabular defects and femoral defects as well as for reconstruction along osteotomy borders or fractures. For stage II ace-tabular bone loss, and some stage III cases, we preferred large-sized press fit cups on the residual bone. When this was not possible for greater stage III and IV segmentary bone loss, reconstruction was achieved with supporting rings anchored in the obturator foramen and applied to disks or other shapes of the second more dense ceramic material which allows greater loading. This second BCP was also very useful when the femoral cortical was too thin to support fixation alone by transfemoral cerclage. The material provided supplementary compression resistance. Results and discussion: There were no biological problems. There were two mechanical acetabular failures and five femoral failures which were secondary to technique errors or poorly adapted implants. Radiographic controls visualised substitute integration in contact with the recipient site. The granules resorbed progressively. The central more dense zone of the ceramic retained its density unchanged at five years while the material was resorbed progressively on the periphery. Histologically, integration of both BCP ceramics was proven on examination of biopsies. Conclusion: Despite this still mid-term follow-up of seven years, we can confirm that BCP ceramics are an attractive alternative for revision THA. In our experience, these ceramic materials are safe and efficient if classical indications and techniques for revision surgery are respected

Introduction: Before proceeding to long-term studies, we studied early clinical results of combined Autologous Chondrocyte Implantation (ACI) and Allogenic Meniscus Transplantation (AMT). Meniscus deficient knees develop early osteo-arthritis (OA) of the knee joint. Autologous Cartilage Implantation (ACI) is contraindicated in case of meniscus deficient knees. And on contrary the Allogenic Meniscus Transplantation (AMT) is contraindicated in cartilage defects in the knee joint. But a combination of the two procedures for bone on bone OA might be a solution for this problem. This was the main purpose of our study. Methods: We studied a consecutive series of eight patients (7 males and 1 female), with an average age= 43 years (29–58), presenting with painful secondary arthritis, due to premature loss of meniscus and chondral defect/s. Median size of the femoral defects was 8.16 cm2 and of the tibial side 2.69 cm2 All patients were treated with a combination of Autologous Chondrocyte implantation (ACI) and Allogenic Meniscus Transplantation (AMT). Chondral defects were covered with periosteum/ Chondroguide membrane, secured in place with in-vitro cultured autologous chondrocytes injected underneath the path. Meniscus placed as load-bearing washer on the surface of ACI of tibia. ACI rehabilitation protocol followed post-operatively. Assessment at the end of one year was done with self-assessed Lysholm score, histology and the MRI scan. Results: Mean pre-operaive Lysholm score was 49 (17–75). This increased to a mean of 66 (26–87) at 1 year, an average increase of 16.4 points. Average one-year satisfaction score was 3 and they were back to all active life style. Five out of eight patients showed significant functional improvement at last post-operative follow-up (2 to 6 years; mean of 3.2 years). Complications were aseptic synovitis in 3 cases. Three failures were noted showig persistant pain and swelling in one, rupture of meniscus in second and third patient had a knee replacement. Arthroscopy at 1 year showed a stable meniscus with all healed peripheral margins in all except in one case with some thinning with no evidence of rejection. Histology of meniscus showed a fibrocartilage well populated with viable cells and the peripheral zone was well vascularised and integrated with capsule. Biopsy of ACI site was predominantly of fibrocartilage with good basal integration with subchondral bone. On MRI scan, allogenic meniscus was well integrated with capsule along the line of repair, showing foci of variable signal intensities within the meniscus. There was no evidence of meniscal subluxation in all but one case showing mild extrusion. ACI graft site showed a varied appearance, with 3 grafts showing focal grade 3to 4 changes. Conclusion: Seven out of eight patients improved post-operatively at one year, in terms of pain relief and increased activity. It’s possible to combine these two techniques together. Short-term outcomes are satisfactory. We could not find any deleterious effects of combining these two techniques together. So we conclude that, this might act as a one step towards a biological knee replacement

Aims

In previous studies, we identified multiple factors influencing the survivorship of hip resurfacing arthroplasties (HRAs), such as initial anatomical conditions and surgical technique. In addition, the University of California, Los Angeles (UCLA) activity score presents a ceiling effect, so a better quantification of activity is important to determine which activities may be advisable or detrimental to the recovered patient. We aimed to determine the effect of specific groups of sporting activities on the survivorship free of aseptic failure of a large series of HRA.

Aims

Metaphyseal cones with cemented stems are frequently used in revision total knee arthroplasty (TKA). However, if the diaphysis has been previously violated, the resultant sclerotic canal can impair cemented stem fixation, which is vital for bone ingrowth into the cone, and long-term fixation. We report the outcomes of our solution to this problem, in which impaction grafting and a cemented stem in the diaphysis is combined with an uncemented metaphyseal cone, for revision TKA in patients with severely compromised bone.

Aims

Although good clinical outcomes have been reported for monolithic tapered, fluted, titanium stems (TFTS), early results showed high rates of subsidence. Advances in stem design may mitigate these concerns. This study reports on the use of a current monolithic TFTS for a variety of indications.