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