Purpose. The aim of this study was to compare the clinical outcomes of the revision TKA in which trabecular metal cones and femoral head allografts were used for large bone defect. Method. Total 53 patients who have undergone revision TKA from July 2013 to March 2017 were enrolled in this study. Among them, 24 patients used trabecular metal cones, and 29 patients used femoral head allografts for large bone defect. There were 3 males and 21 females in the metal cone group, while there were 4 males and 25 females in the allograft group. The mean age was 70.2 years (range, 51–80) in the femoral head allograft group, while it was 79.1 years (range, 73–85) in the metal cone group. Bone defect is classified according to the AORI classification and clinical outcomes were evaluated with Visual Analogue Scale (VAS), Hospital Special Surgery-score (HSS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Knee Injury and Osteoarthritis Outcome Score (KOOS), and ROM. Operation time was also evaluated. We used radiographs to check complications such as migration or loosening. We took follow-up x-rays and 3D CT of the patients, to assess the mean bone union period. Shapiro-Wilk test was done to check normality and Student T-test and Mann Whitney U-test were done for comparison between two groups. Result. The mean follow-up period was 3 .75 years (Range; 2.1 ∼ 5.75). The pre-op scores did not show significant difference. The mean VAS in the allograft and trabecular metal cone groups was 2.1 ± 0.87 and 1.8 ± 0.53, respectively (p = 0.16). The mean HSS score were 76.3 ± 5.51 and 79.2 ± 4.12 respectively (p = 0.13) and the mean WOMAC scores were 15.1 ± 3.25 and 14.8 ± 3.31 respectively (p = 0.06), and the mean KOOS scores were 27.8 ± 4.77 and 25.5 ± 4.84, respectively (p = 0.07). The mean ROM ranges were 100.6 ± 17.54 and 101.3 ± 19.22, respectively (p = 0.09). But the mean operation time of the allograft and trabecular metal cone groups was 137 minutes (Range; 111–198) and 102minutes (Range; 93 −133) (p=0.02) respectively, which showed statistical significance. In follow-up x-rays, no migration or loosening of the implants, osteolysis and other complications were found in both groups. In follow-up 3D CT, osteointegration was seen at the trabecular metal cone site, host bone being interpreted to the host bone. The allograft group showed fibrous and stable union in follow-up 3D CT. Conclusion. According to this study, in case of revision TKA with large bone defect, using whether allograft or trabecular metal cones did not affect the clinical outcomes. However, operation time was significantly shorter in trabecular metal cone group, therefore, in patients with poor general condition along with severe underlying diseases, usage of trabecular metal cone would be a better choice to shorten operation time and ease postoperative care. Keywords. Revision TKA, metal cone, allograft, bone defect. For any figures or tables, please contact authors directly

The objective of this study was to consider whether an impaction bone graft (IBG) with their own bone tips surrounded with an X-changed rim mesh was useful when en bloc bone inplantation was not possible for a total knee replacement with large bone defect. Materials and Method. 4 cases and 5 knees (OA: 2 cases 3 knees, RA: 2 cases 2 knees) more than 2 years after the IBG procedure was done using X-changed rim mesh for the large medial tibial defect. All 4 cases were ladies, with the average age being 66.2 years old at that point of the procedure. A medial and posterior release for the connective tissues of knee was performed. The post and pre radiographic evaluations were done by knee society score and JOA score. All the defect or abrasion of the weighted surface was more than 5 mm from the last stage of osteoarthritis. We used a posterior-stabilized type of TKA (Zimmer nexgen), then took radiographs at pre and post operation periods and evaluated the knee scores, FTA, radiolucent line, range of motion and more than 2 years after the operation. Result. The graft bones were not depressed after more than 2 years and all the patients were satisfied the condition of their knees and made no mention of any knee pain. The average range of motion of their knee joint was: Pre-operation, passive flexion 133°, passive extension -21°; Post-operation, passive flexion 149°, passive extension -3°. All of the patients did not complain during movement and their walking ability including going up and down stairs was not reduced more than 2 years later. The component placement angle was not changed. The radiolucent line of the femur and tibiae did not appear. The average femoro-tibial angle improved from 197° to 173° over the course of two years. The femoral/tibial component setting angle was not changed more than 2 years after the TKA operation procedure. Radiolucent zone and component sinking was not seen on both side of femur and tibiae. Conclusion. After this survey we've found that an IBG procedure with an X-changed rim mesh is a good treatment for large bone defect of the tibiae. We can use this technique if we are not able to take out en bloc bone from their own tibiae or if their en bloc bone is crushed into pieces when trying to fix the bone to their tibiae because of bone fragility

Introduction. Reconstruction of large defect of tibia following infection is considered as one of the most difficult problem facing the orthopaedic surgeon. Amputation with modern prosthetic fitting is a salvage procedure to treat big defects, which gives a functional result with unpredictable psychological impact. Materials & Methods. Between January 2000 and January 2021, 56 patients (30 males and 26 females) with big defects following infection and post traumatic injury of the tibia were treated. The mean age of the patients at the time of surgery was 20.5 years (4–24 years). The fibula was mobilized medially to fill the defect and was fixed with Ilizarov fixator. The average size of the defects reconstructed was 18.5 cm (17–20 cm). Results. The average time for complete union was 8.6 months (range, 5–9 months). At final follow-up all patients had fully united. We found leg length discrepancy in 52 patients and that was corrected by re-lengthening of the solid new regenerate bone. Conclusions. The Ilizarov method has been shown to be an effective method of treating Tibialization of fibula for reconstruction of big tibial defects

Introduction. The purpose of this study is to evaluate the radiological and clinical outcomes in Northern Ireland of free vascularised fibular bone grafting for the treatment of humeral bone loss secondary to osteomyelitis. Upper limb skeletal bone loss due to osteomyelitis is a devastating and challenging complication to manage for both surgeon and patient. Patients can be left with life altering disability and functional impairment. This limb threatening complication raises the question of salvage versus amputation and the associated risk and benefits of each. Free vascularised fibula grafting is a recognised treatment option for large skeletal defects in long bones but is not without significant risk. The benefit of vascularised over non-vascularised fibula grafts include preservation of blood supply lending itself to improved remodeling and osteointegration. Materials & Methods. Sixteen patients in Northern Ireland had free vascularised fibula grafting. Inclusion criteria included grafting to humeral defects secondary to osteomyelitis. Six patients were included in this study. Patients were contacted to complete DASH (Disabilities of the Arm, Shoulder and Hand) questionnaires as our primary outcome measure. Secondary outcome measures included radiological evaluation of osteointegration and associated operative complications. Complications were assessed via review of Electronic Care Record outpatient and in-patient documents

Introduction. Autologous fat grafting has favourable potential as a regenerative strategy and is the current gold-standard to repair large contour defects, as needed in breast reconstruction after mastectomy and traumatic soft tissue reconstruction. Clinically, there is a limit on the volume of lipoaspirate which can be utilised to repair a soft-tissue defect. Surgical complications are the result of poor structural fidelity of lipoaspirate and graft resorption as a filling material and are hindered further by poor graft vascularisation. This study aims to develop injectable lipoaspirate-derived adipose tissue grafts with enhanced biologically and clinically-admissible structural and functional properties adopting light photocrosslinking of unmodified lipoaspirate. Methods. Patient-derived lipoaspirate was harvested and crosslinked using novel photoinitiator and exposure to visible light (wavelength 450nm) in surgery, establishing bonds between extracellular matrix (ECM) proteins within the material. The degree of crosslinking was tuned (photoinitiator concentration, light exposure, light intensity) and covalent bond formation measured using mass spectrometry. To predict patient response, SWATH-MS was used to identify differences in patient ECM and crosslinked grafts were implanted in vivo using a subcutaneous mouse model. Functional vessel formation and resorption were quantified using micro-CT and tissue-remodelling was assessed via histology. Results. There was an increase in the relative abundance of covalent bonds present with increasing degree of crosslinking. When injected, crosslinked lipoaspirate had better shape fidelity compared with native lipoaspirate – demonstrated by a smaller fibre diameter. Crosslinked lipoaspirate remained viable over long term culture and resulted in more predictable resorption profiles when implanted in vivo. Conclusions. The crosslinking approach described here is tunable and functional across different patient samples. Improving the structural properties of lipoaspirate through minimal manipulation has clinical utility for the delivery of grafts with higher shape fidelity and therefore increased graft survival when implanted

Introduction. Impaction bone grafting (IBG) is a reliable technique for acetabular revision surgery with large segmental defects. However, bone graft resorption and cup migration are some of the limitations of this tecnique. We assess frequency and outcome of these complications in a large acetabular IBG series. Patients and Methods. We analysed 330 consecutive hips that received acetabular IBG and a cemented cup in revision surgery with large bone defects (Paprosky types 3A and 3B). Fresh-frozen femoral head allograft was morselized manually. The mean follow-up was 17 years (3–26). All data were prospectively collected. Kaplan-Meier survivorship analysis was performed. Changes in different paremeters regarding cup position were assessed pre- and postoperatively and at the follow- up controls. Only variations greater than 5º and 3 mm were considered. Results. The mean Harris Hip Score improved from 48.3+8.5 to 84.6+12.8 at final follow-up. The radiological analysis showed cup migration in 42 hips. The mean appearance time was 4.3 years (range, 1–25). Migration was progressive and painful in 27 hips (67.5%) requiring cup revision. Lateral mesh was more frequently associated with migrated cups (p=0.034). Cup tilt was found in 37 out 42 migrated cups, however cranial migration was more frequent in progressive migrated cups (p=0.02). There were 34 re-revisions, 27 due to aseptic cup loosening, 6 due to dislocation and one due to infection. The survival rate for any cause at 16 years was 81.2% (95% Confidence Interval (CI): 74.0 to 88.4) and for aseptic cup loosening was 83.4% (95% CI: 76.2–90.6). In all surviving hips trabecular incorporation was observed without radiolucent lines. Conclusions. IBG continues to be a reliable technique for large defects in acetabular revision surgery. Bone graft resorption and cup migration was not frequent in this large series and one-third of cases were not progressive. Cup migration was more frequent in cases with a segmental roof defect in which a lateral mesh was used

Introduction. The bone defect reconstruction is the first step of successful primary or revision TKA in case of large bone defect. If the defect is not reconstructed adequately, we can neither preserve knee joint function nor guarantee long survival of the implant. Allogeneic bone graft is known to be the treatment of choice in large defect. However the surgical technique is demanding and incorporation failure is constant issue of the allogeneic bone graft. We propose new bone defect reconstruction technique using multiple screws and cement. Material and method. From April 2012 to April 2014, 12 patients with large defect which could not be reconstructed with metal augment were involved in this study. The bone defect type was 10 cases of 2A and 2 cases of 2B according to AORI (Anderson Orthopedic Research Institute) classification. The defect was reconstructed with multiple screws and cementing technique by single surgeon (WS Cho). Average follow-up period was 15 months. (24 ∼ 1 month). Result. We analyzed 6 patients whose follow-up periods were more than 12 months. Average ROM was 107' and clinical scores were 86 by HSS, 93 by KS and 11 by WOMAC respectively. No complications such as infection and loosening were developed. Mean surgical time was 1 hour and 57 minutes. Conclusion. In short term follow-up, cementing technique using multiple screws can be a solution for large bone defect reconstruction

Introduction. Aneurysmal bone cysts commonly found in lower limbs are locally aggressive masses that can lead to bony erosion, instability and fractures. This has major implications in the lower limbs especially in paediatric patients, with potential growth disturbance and deformity. In this case series we describe radical aneurysmal bone cyst resection and lower limb reconstruction using cable transport and syndesmosis preservation. Materials & Methods. Case 1 - A 12-year-old boy presented with a two-week history of atraumatic right ankle pain. An X-ray demonstrated a distal tibia metaphyseal cyst confirmed on biopsy as an aneurysmal bone cyst. The cyst expanded on interval X-rays from 5.5cm to 8.5cm in 9 weeks. A wide-margin en-bloc resection was performed leaving a 13.8cm tibial defect. A cable transport hexapod frame and a proximal tibial osteotomy was performed, with syndesmosis screw fixation. The transport phase lasted 11 months. While in frame, the boy sustained a distal femur fracture from a fall. The femur and the docking site were plated at the same sitting and frame removed. At one-year post-frame removal he is pain-free, with full ankle dorsiflexion but plantarflexion limited to 25 degrees. He has begun graduated return to sport. Results. Case 2 - A 12-year-old girl was referred with a three-month history of lateral left ankle swelling. X-ray demonstrated an aneurysmal bone cyst in the distal fibula metaphysis. The cyst grew from 4.2 × 2.3cm to 5.2 × 3.32cm in 2 months. A distal fibula resection (6.2cm) with syndesmosis fixation and hexapod cable transport frame were undertaken. The frame was in situ for 13 weeks and during this time she required an additional osteotomy for premature consolidation and had one pin site infection. After 13 weeks a second syndesmosis screw was placed, frame removed, and a cast applied. 3 months later she had fibular plating, BMAC and autologous iliac crest bone graft for slow union. At 3 years post-operative she has no evidence of recurrence, is pain-free and has no functional limitation. Conclusions. We describe two cases of ankle syndesmosis preservation using cable transport for juxta-articular aneurysmal bone cysts. This allows wide resection to prevent recurrence while also preserving primary ankle stability and leg length in children. Both children had a minor complication, but both had an excellent final outcome. Cable bone transport and prophylactic syndesmosis stabilization allows treatment of challenging juxta-articular aneurysmal bone cysts about the ankle. These techniques are especially useful in large bone defects

Metaphyseal bone loss, due to loosening, osteolysis or infection, is common with revision total knee arthroplasty (TKA). Small defects can be treated with screws and cement, bone graft, and non-porous metal wedges or blocks. Large defects can be treated with bulk structural allograft, impaction grafting, or highly porous metal cones. The AORI classification of bone loss in revision TKA is very helpful with pre-operative planning. Type 1 defects do not require augments or graft—use revision components with stems. Type 2A defects should be treated with non-porous metal wedges or blocks. Type 2B and 3 defects require a bulk structural allograft or porous metal cone. Highly-porous metal metaphyseal cones are a unique solution for large bone defects. Both femoral (full or partial) and tibial (full, stepped, or cone+plate) cones are available. These cones substitute for bone loss, improve metaphyseal fixation, help correct malalignment, restore joint line, and permit use of a short cemented stem. The technique for these cones involve preparing the remaining bone with a high speed burr and rasp, followed by press-fit of the cone into the remaining metaphysis. The interface is sealed with bone graft and putty. The fixation and osteoconductive properties of the outer surface allow ingrowth and biologic fixation. The revision knee component is then implanted, with antibiotic-cement, into the porous cone inner surface, which provides superior fixation compared to cementing into deficient metaphyseal bone. There are several manufacturers that provide porous cones for knee revision, but the tantalum-“trabecular metal” cones have the largest and longest clinical follow-up. The advantages of the trabecular metal cone compared to allograft include: technically easier; biologic fixation; no resorption; and lower risk of infection. The disadvantages include: difficult extraction and intermediate-term follow-up. The author has reported the results of 33 trabecular metal cones (9 femoral, 24 tibial) implanted in 27 revision cases at 2–5.7 years follow-up. One knee (2 cones) was removed for infection. All but one cone showed osseointegration. Multiple other studies have confirmed these results. Trabecular metal cones are now the author's preferred method for the reconstruction of large bone defects in revision TKA

Introduction. We demonstrate the preliminary results with a novel technique to solve large bone defects using two lengthening nails, working together and aligned in a custom made device. An illustrative case that successfully produced 17 cm bone in 3.5 months, is presented. Materials and Methods. A 28 year old healthy male presented with a slowly growing mass in the left femur. No general symptoms were reported, no weight loss, no previous illness. Histopathology, CT and MRI scans revealed a malignant diaphyseal bone tumor. A three-stage trifocal bone transport was projected and conducted based on a 3D model test. Results. Trifocal bone transport using two lengthening nails in a custom made device, reduced the 17 cm bone defect in 3.5 months. Follow up was 9 months. Conclusions. The presented technique successfully solved the clinical problem and is a showcase for further developments of internal devices for complex and large bone losses and lengthenings

Metaphyseal bone loss, due to loosening, osteolysis or infection, is common with revision total knee arthroplasty (TKA). Small defects can be treated with screws and cement, bone graft, and non-porous metal wedges or blocks. Large defects can be treated with bulk structural allograft, impaction grafting, or highly porous metal cones. The AORI classification of bone loss in revision TKA is very helpful with preoperative planning. Type 1 defects do not require augments or graft—use revision components with stems. Type 2A defects should be treated with non-porous metal wedges or blocks. Type 2B and 3 defects require a bulk structural allograft or porous metal cone. Trabecular metal (TM) metaphyseal cones are a unique solution for large bone defects. Both femoral (full or partial) and tibial (full, stepped, or cone+plate) TM cones are available. These cones substitute for bone loss, improve metaphyseal fixation, help correct malalignment, restore joint line, and permit use of a short cemented stem. The technique for these cones involve preparing the remaining bone with a high speed burr and rasp, followed by press-fit of the cone into the remaining metaphysis. The interface is sealed with bone graft and putty. The fixation and osteoconductive properties of the outer surface allow ingrowth and biologic fixation. The revision knee component is then cemented into the porous cone inner surface, which provides superior fixation compared to cementing into deficient metaphyseal bone. The advantages of the TM cone compared to allograft include: technically easier; biologic fixation; no resorption; and lower risk of infection. The disadvantages include: difficult extraction and intermediate-term follow-up. The author has reported the results of 33 TM cones (9 femoral, 24 tibial) implanted in 27 revision cases at 2–5.7 years follow-up. One knee (2 cones) was removed for infection. All but one cone showed osseointegration. TM cones are now the preferred method for the reconstruction of large bone defects in revision TKA

Uncontained acetabular defects with loss of superior iliac and posterior column support (Paprosky 3) represent a reconstructive challenge as the deficient bone will preclude the use of a conventional hemispherical cup. Such defects can be addressed with large metallic constructs like cages with and without allograft, custom tri-flange cups, and more recently with trabecular metal augments. An underutilised alternative is impaction bone grafting, after creating a contained cavitary defect with a reinforcement mesh. This reconstructive option delivers a large volume of bone while using a small-size socket fixed with acrylic cement. Between 2005 and 2014, 21 patients with a Paprosky 3B acetabular defect were treated with cancellous, fresh frozen impaction grafting supported by a peripheral reinforcement mesh secured to the pelvis with screws. A cemented all-polyethylene cup was used. Pre-operative diagnosis was aseptic loosening (15 cemented and 6 uncemented). The femoral component was revised in 10 patients. Post-operative course consisted of 3 months of protected weight bearing. Patients were followed clinically and radiographically. One patient had an incomplete post-operative sciatic palsy. After a mean follow up of 47 months (13 to 128) none of the patients required re-revision of the acetabular component. One asymptomatic patient presented with aseptic loosening 9 years post-operatively. Hardware failure was not observed. All patients had radiographic signs of graft incorporation and bone remodeling. There were no dislocations. The early and mid-term results of revisions of large acetabular defects with this technique are encouraging. Reconstitution of hip center of rotation and bone stock with the use of a small-size implant makes this technique an attractive option for large defects. Longer follow-up is needed to assess survivability

Background. Cup migration and bone graft resorption are some of the limitations after acetabular impaction bone grafting (IBG) technique in revision hip surgery when used for large segmental defects. We asked whether the use of a metallic mesh may decrease the appearance of this complication. We compared the appearance of loosening in patients with a bone defect 3A or 3B according to Paprosky. Materials and Methods. We assessed 204 hips operated with IBG and a cemented cup according to Slooff et al between 1997 and 2004. There were 100 hips with a preoperative bone defect of 3A and 104 with a 3B. We used 142 medial and/or rim metallic meshes for uncontained defects. The mean follow-up for unrevised cups was 10.4 years. We detemined postoperative radiological cup position and acetabular reconstruction of the hip center according to Ranawat in both groups. We assessed the appearance of radiological loosening and resorption of the graft. Results. Postoperative cup position improved in both groups (p<0.001 for all parametres). Distance to the approximate center of the hip decreased from 23.5 to 8.5 mm. 8 hips showed radiological loosening in group with a bone defect 3A and 16 in group 3B. The survival rate for loosening at 15 years was for 83.2 +12% for group 3A and 72.5 + 12% for group 3B (Mantel-Cox, p=0.04). The survival rate when using mesh or not at 15 years for loosening was: No Mesh 89.1 + 14%, Medial mesh 84.9 + 12%, Rim 79.6 + 12%, Medial and Rim 53.9 + 22 % (Mantel Cox, p=0.008). Patients with a bone defect 3B and a rim metallic mesh had a higher risk for loosening (p=0.047; Hazard Ratio: 2.36, Confidence Interval 95% (CI) 1.01–5.5, and, p=0.026; HR: 3.7, CI 95%: 1.13–12.4, respectively). Conclusions. IBG provides an improvement of the reconstruction of the rotation of the hip centre in acetabular revision surgery. Although results are good for contained or medial large defects, hips with a rim large segmental defect may need other options for reconstruction of these challenged surgeries

Introduction. Revision of total knee endoprostheses (TKA) is increasing in number and causes rising healthcare costs. For constrained prostheses, the use of intramedullar femoral stems is standard. However, there is a big variety of available stem types with regard to length, type of fixation (cemented vs. hybrid) and fixation area (diaphyseal vs. metaphyseal). The aim of this biomechanical study was to investigate the primary stability of revision TKA with different stem types and different femoral bone defects, to find out whether smaller or shorter stems may achieve sufficient stability while preserving bone for re-revision. Methods. 30 right human femora were collected, fresh frozen and divided in six groups, matching for age, gender, height, weight and bone density. In group 1–3 a bone defect of AORI type F2a (15mm medial) and in group 4–6 a defect of AORI type F3 (25mm on both sides) was created. In all six groups the same modular femoral surface component (Endo-Model-W, Waldemar Link) was used, combined with different stem types (100/ 160 mm cemented / uncemented / standard/ anatomical with / without cone). Additionally, one trial was set up, omitting the modular stem. The correct fit of the implants was confirmed by fluoroscopy. After embedding, specimens were mechanically loaded 10mm medially and parallel to the mechanical femoral axis with an axial force of 2700N and a torsional moment of 5.6Nm at a flexion angle of 15° with respect to the coupled tibial plateau according to in-vivo gait load for 10,000 cycles (1Hz) in a servohydraulic testing machine (Bionix, MTS). The relative movement between implant, cement and distal femur was recorded using a stereo video system (Aramis3D,gom). An axial pull-out test at 1mm/min was performed after dynamic loading. Results. No clinical or radiological loosening of any configuration was observed. In all cases, relative movements were below 20µm and the differences between groups were very small. There were two cases, the trial without stem and one probe with short cemented stem with poor cementing technique (not included in the group result), which showed greatly increased relative movements. Pull-out test exhibited that forces of short stems with cones and uncemented anatomical cone stems with large defects (groups 4–6) were not significantly different to cemented stems in small defects. Discussion. Despite the high experimental load, even causing bone fracture in two cases, no difference between the investigated stem types concerning primary stability was found, partially probably due to the high inter-individual variations. Possible long-term differences cannot be assessed with in-vitro testing representing direct post-op situation, but the results might partially explain the controversial clinical observations and suggest further investigation on patient specific decisive parameters for implant choice. For any figures or tables, please contact authors directly

Uncontained acetabular defects with loss of superior iliac and posterior column support (Paprosky 3B) represent a reconstructive challenge as the deficient bone will preclude the use of a conventional hemispherical cup. Such defects can be addressed with large metallic constructs like cages with and without allograft, custom tri-flange cups, and more recently with trabecular metal augments. An underutilised alternative is impaction bone grafting, after creating a contained cavitary defect with a reinforcement mesh. This reconstructive option delivers a large volume of bone while using a small-size socket fixed with acrylic cement. Between 2006 and 2014, sixteen patients with a Paprosky 3B acetabular defect were treated with cancellous, fresh frozen impaction grafting supported by a peripheral reinforcement mesh secured to the pelvis with screws. A cemented all polyethylene cup was used. Preoperative diagnosis was aseptic loosening (10 cemented and 6 non-cemented). The femoral component was revised in 9 patients. Postoperative course consisted of 3 months of protected weight bearing. Patients were followed clinically and radiographically. One patient had an incomplete postoperative sciatic palsy. After a mean follow up of 40 months (24 to 104) none of the patients required re-revision. One asymptomatic patient presented with aseptic loosening 9 years postoperatively. Hardware failure was not observed. All patients had radiographic signs of graft incorporation and bone remodeling. There were no dislocations. The early and mid-term results of revisions for large acetabular defects with this technique are encouraging. Reconstitution of hip center of rotation and bone stock with the use of a small-size implant make this technique an attractive option for these large defects. Longer follow-up is needed to assess survivability

Bone grafts are a useful option to treat large posteromedial defects in tibia which are usually seen in medial condyle of the tibia in severe varus knees and lateral condyle in valgus knees. Contained defects can be treated using cancellous bone chips/graft. Uncontained peripheral defects may be treated using cement with or without screw augmentation for small defects. Large defects > 25 % of tibial plateau and > 5 mm deep may need structural bone graft or impaction bone grafting or metal wedges. The use of bone grafts is a viable alternative for the treatment of massive bone loss. For stable fixation of the components, we performed osseous reconstruction of tibial condyle using autologous structural bone grafts /impaction bone grafting. We used structural bone graft for 62 tibial defects in severe varus knees in 675 primary TKR. Grafts originating from the femoral condyles were fixed with screws. Morselised autograft supported by mesh, fixed with screws, were used in 8 patients. Bilateral bone grafting was done in 28 patients. Goal was to obtain firm seating of the tibial tray on a rim of viable bone along with rigid press fixation of the medullary stem. We observed an average 70-point postoperative increase in knee function according to HSS score. Graft incorporation was seen in all patients at average seven year follow-up. Autologous bone grafts can be successfully used for reconstruction of large osseous defects. It is available then and there, is biological and cost effective

Metaphyseal bone loss is common with revision total knee arthroplasty (TKA). The causes of bone loss include: osteolysis, loosening, infection, iatrogenic or a combination. Small defects can be treated with screws and cement, bone graft, and non-porous metal wedges or blocks. Large defects can be treated with bulk structural allograft, impaction grafting, or highly porous metal cones or augments. The AORI classification of bone loss in revision TKA is very helpful with preoperative planning. Type 1 defects do not require augments or graft—use revision components with stems. Type 2 defects should be treated with non-porous metal augments—wedges or blocks. Type 3 defects require a bulk structural allograft or large highly porous metal cone. Trabecular metal (TM) metaphyseal cones are a unique solution for large bone defects. There are both femoral (full or partial) and tibial (full or stepped) TM cones available. These cones substitute for bone loss, improve metaphyseal fixation, help correct malalignment, restore joint line, and perhaps, permit use of a shorter stem. The technique for these cones involve sculpturing of the remaining bone with a high speed burr and rasp, followed by press-fit of the cone into the remaining metaphyseal bone. The interface is sealed with bone graft and putty. The fixation and osteoconductive properties of the outer surface allow ingrowth and hopefully long term biologic fixation. The revision knee component is then cemented into the porous cone inner surface, which provides superior fixation compared to deficient metaphyseal bone. The advantages of the TM cone compared to allograft include: technically easier; biologic fixation; no resorption; and (?) lower risk of infection. The disadvantages include: difficult extraction and relatively short-term follow-up. The author has reported the results of 33 TM cones (9 femoral, 24 tibial) implanted in 27 revision cases at 2–5.7 years follow-up. One knee (2 cones) was removed for infection. All but one cone showed osseointegration. TM cones are a promising method for the reconstruction of large bone defects in revision TKA

Large femoral neck defects pose a great challenge for orthopedic surgeons and are frequently associated with neglected femoral neck fractures, post infective sequale and failed implants around femoral neck. We present our technique (AIIMS Box Technique) of neck reconstruction aiming to preserve the natural femoral head and restoring the function of hip in cases of large femoral neck defects. A total number of 52 patients (age range 20 to 56 years with an average of 38 years) with large femoral neck defects were treated from January 1990 to May 1997 and were followed for a minimum of 10 years (range 10 to 17 years). Neck defect was converted into a box using osteal flaps (Base from greater trochanter, Anterior wall from head, Quadratus Femoris muscle pedicle graft posteriorly). This box was filled with cancellous bone autograft along with three cancellous screw fixation. Union occurred in all patients in a mean time of 16 weeks (range 12–20 weeks). One patient in our series had avascular necrosis (AVN) of femoral head. Eighteen out of 52 results were classified as excellent, 28 good and 6 fair. No patient had poor result. Good functional mobility including squatting was seen in all but two patients. Complications included coxa vara in two patients, hardware problems in four patients. Our study shows that large femoral neck defects can be managed successfully with preservation of vascularity of femoral head. This procedure can be considered an alternative to excisional or replacement arthroplasty, particularly in young adults

Pelvic discontinuity remains one of the most difficult reconstructive challenges during acetabular revision. Bony defects are extremely variable and remaining bone quality may be extremely poor. Careful pre-operative imaging with plain radiographs, oblique views, and CT scanning is recommended to improve understanding of the remaining bone stock. It is wise to have several options available intra-operatively including metal augments, jumbo cups, and cages. Various treatment options have been used with variable success. The principles of management include restoration of acetabular stability by “connecting” the ilium to the ischium, and by (hopefully) allowing some bony ingrowth into a porous surface to allow longer-term construct stability. Posterior column plates can be useful to stabilise the pelvis, and can supplement a trabecular metal uncemented acetabular component. Screws into the dome and into the ischium are used to span the discontinuity. More severe defects may require so-called “cup-cage” constructs or trabecular metal augmentation distraction techniques. The most severe defects typically necessitate custom triflange components. Triflange constructs allow broad based contact with remaining bone stock, and can span surprisingly large defects. Recent cost analyses have shown that custom triflange constructs are comparable to cup-cage-augment reconstructions. The results of these various solutions to manage pelvic discontinuity is extremely variable, however, it is fair to conclude that constructs that allow some bony ingrowth have demonstrated improved survivorship when compared to historical treatments such as bulk allografts protected by cages. The author prefers a posterior column plate and a trabecular metal cup for simple discontinuities, a cup-cage for larger defects, and a custom triflange for the most severe defects. Pre-operative imaging is critical to guide this decision-making, and careful attention to detail is important to obtain a stable, durable construct

Several methods of treatment are available in the revision of loose acetabular components associated with significant bone loss. Jumbo cups are the preferred treatment for large acetabular defects with segmental and cavitary defects. By definition, a jumbo cup has a minimum diameter of 62 mm in women, 66 mm in men, or is greater than 10 mm larger than the normal contralateral acetabulum. They are easier to use and less expensive than cages, bulk supporting allografts, or custom cups. Proper technique is for bone to be moved, not removed. The acetabulum is reamed larger to gain more host-bone surface area. The acetabulum should then accommodate the large shell and maximise the shell host-bone contact for long-term biological fixation. The preferred shell is one with high porosity to maximise the potential area for bone ingrowth when less bone contact is present. At least 50% host-bone to shell contact is ideal but not mandatory. The larger surface area of a jumbo cup provides more opportunity for bone ingrowth. Therefore having an initially stable cup is more important than the amount of host-bone contact. Jumbo cups are only contraindicated in acetabulae that lack the superior lateral acetabulum and the posterior column. In that situation, fortunately uncommon, a cup/ cage reconstruction is used. We reported a retrospective review of 690 acetabular revisions performed from 1986–2005. Jumbo cups were used in 196 (28%) of all the acetabular revisions and greater than 95% of the cases with large defects. This is the largest series or revisions with jumbo cups reported. Significant bony deficiencies were present; 68% were Paprosky type II and 25% were Paprosky type III. The average follow-up for the jumbo cups was ten years. Five revisions and two resection arthroplasties were performed for failure. The probability of survival of the jumbo cups was 98% at four years and 96% at 16 years. Porous jumbo cup acetabular revision with supplemental screw fixation provides good to excellent intermediate- and long-term outcomes