Aim: Impaction bone grafting is an established technique for the restoration of bone loss at revision hip surgery. Preformed stainless steel meshes have been recently introduced to augment graft containment. We present our results of acetabular impaction grafting at a mean of 4 years, with particular reference to the use of preformed steel meshes. Methods: 72 consecutive total hip replacements (7 primary and 65 revision) in 69 patients underwent acetabular impaction grafting with morsellised fresh frozen allograft through a posterior approach. In 47 cases there were uncontained defects (46 segmental or combined deficiencies, one pelvic discontinuity) necessitating the use of a preformed steel mesh, secured with multiple small fragment screws to contain the impacted bone graft. All the operations were done by the senior author in a district general hospital. Results: At mean follow-up of 4 years (range 18 to 92 months), no case has been lost to follow up. The Merle d’Aubigne Postel hip scores averaged 5.3 (pain), 4.2 (walking ability), and 5.3 (range of movement). (Charnley group A -26 patients, group B -19, group C -24). There were no peri-operative deaths or deep infections. There have been no revisions for septic or aseptic loosening. There were 2 cases of early post operative dislocation which stabilised after closed reduction. One case of recurrent disclocation required cup revision. There was one case of radiographic loosening without cup migration. This patient remains pain free and there are no plans for revision. In all other cases, radiographs suggest graft incorporation, with no significant radiolucent lines, acetabular component or mesh migration. There have been no complications relating to the use of the preformed mesh. Conclusion: The results of this study are encouraging. By using preformed metallic meshes it is possible to manage all cases of acetabular loss, irrespective of severity, encountered during total hip replacement with acetabular impaction grafting

Structural allografts may be used to manage uncontained bone defects in revision total knee replacement (TKR). However, the availability of cadaver grafts is limited in some areas of Asia. The aim of this study was to evaluate the mid-term outcome of the use of femoral head allografts for the reconstruction of uncontained defects in revision TKR, focusing on complications related to the graft. We retrospectively reviewed 28 patients (30 TKRs) with Anderson Orthopaedic Research Institute (AORI) type 3 bone defects, who underwent revision using femoral head allografts and stemmed components. The mean number of femoral heads used was 1.7 (1 to 3). The allograft–host junctions were packed with cancellous autograft. At a mean follow-up of 76 months (38 to 136) the mean American Knee Society knee score improved from 37.2 (17 to 60) pre-operatively to 90 (83 to 100) (p < 0.001). The mean function score improved from 26.5 (0 to 50) pre-operatively to 81 (60 to 100) (p < 0.001). All the grafts healed to the host bone. The mean time to healing of the graft was 6.6 months (4 to 16). There have been no complications of collapse of the graft, nonunion, infection or implant loosening. No revision surgery was required. The use of femoral head allografts in conjunction with a stemmed component and autogenous bone graft in revision TKR in patients with uncontained bone defects resulted in a high rate of healing of the graft with minimal complications and a satisfactory outcome. Longer follow-up is needed to observe the evolution of the graft. Cite this article: Bone Joint J 2013;95-B:643–8

We retrospectively reviewed 44 consecutive patients (50 hips) who underwent acetabular re-revision after a failed previous revision that had been performed using structural or morcellised allograft bone, with a cage or ring for uncontained defects. Of the 50 previous revisions, 41 cages and nine rings were used with allografts for 14 minor-column and 36 major-column defects. We routinely assessed the size of the acetabular bone defect at the time of revision and re-revision surgery. This allowed us to assess whether host bone stock was restored. We also assessed the outcome of re-revision surgery in these circumstances by means of radiological characteristics, rates of failure and modes of failure. We subsequently investigated the factors that may affect the potential for the restoration of bone stock and the durability of the re-revision reconstruction using multivariate analysis. At the time of re-revision, there were ten host acetabula with no significant defects, 14 with contained defects, nine with minor-column, seven with major-column defects and ten with pelvic discontinuity. When bone defects at re-revision were compared with those at the previous revision, there was restoration of bone stock in 31 hips, deterioration of bone stock in nine and remained unchanged in ten. This was a significant improvement (p <  0.001). Morselised allografting at the index revision was not associated with the restoration of bone stock. . In 17 hips (34%), re-revision was possible using a simple acetabular component without allograft, augments, rings or cages. There were 47 patients with a mean follow-up of 70 months (6 to 146) available for survival analysis. Within this group, the successful cases had a minimum follow-up of two years after re-revision. There were 22 clinical or radiological failures (46.7%), 18 of which were due to aseptic loosening. The five and ten year Kaplan–Meier survival rate was 75% (95% CI, 60 to 86) and 56% (95% CI, 40 to 70) respectively with aseptic loosening as the endpoint. The rate of aseptic loosening was higher for hips with pelvic discontinuity (p = 0.049) and less when the allograft had been in place for longer periods (p = 0.040). . The use of a cage or ring over structural allograft bone for massive uncontained defects in acetabular revision can restore host bone stock and facilitate subsequent re-revision surgery to a certain extent. Cite this article: Bone Joint J 2014;96-B:319–24

The major causes of revision total knee are associated with some degree of bone loss. The missing bone must be accounted for to insure success of the revision procedure, to achieve flexion extension balance, restore the joint line to within a centimeter of its previous level, and to assure a proper sizing especially the anteroposterior diameter of the femoral component. In recent years, clinical practice has evolved over time with a general move away from a structural graft with an increase in utilisation of metal augments. Alternatives include cement with or without screw fixation, rarely, with the most common option being the use of metal wedges. With the recent availability of highly porous augments, the role of metal augmentation has increased. Bone graft is now predominantly used in particulate form for contained defects with more limited use of structural graft. The role of the allograft-prosthetic composite has become more limited. For the elderly with osteopenia and massive bone loss, complete metal substitution with an oncology prosthesis has become more common. The degree of bone loss is a major determinant of the management strategy. For contained defects less than 5 mm, cement alone, with or without screw supplementation, may be adequate. For greater than 5 mm, morselised graft is frequently used. For uncontained defects of up to 15 mm or more, metal augmentation is the first choice. Bone graft techniques can be utilised in this setting, however, these are more time consuming and technically demanding with little demonstrated advantage. For larger, uncontained defects, newer generation highly porous augments and step wedges are useful. Large contained defects can be dealt with utilising impaction grafting, similar to the hip impaction grafting technique. Massive distal defects are expeditiously managed with oncology defects in the case of periprosthetic fracture and/or massive osteolysis particularly when combined with osteopenia in an elderly, low demand patient. Surgeons must be familiar with an array of techniques in order to effectively deal with the wide spectrum of bone defects encountered during revision total knee arthroplasty

The treatment of bony defects of the tibia at the time of revision total knee replacement is controversial. The place of compacted morsellised bone graft is becoming established, particularly in contained defects. It has previously been shown that the initial stability of impaction-grafted trays in the contained defects is equivalent to that of an uncemented primary knee replacement. However, there is little biomechanical evidence on which to base a decision in the treatment of uncontained defects. We undertook a laboratory-based biomechanical study comparing three methods of graft containment in segmental medial tibial defects and compared them with the use of a modular metal augment to bypass the defect. Using resin models of the proximal tibia with medial defects representing either 46% or 65% of the medial cortical rim, repair of the defect was accomplished using mesh, cement or a novel bag technique, after which impaction bone grafting was used to fill the contained defects and a tibial component was cemented in place. As a control, a cemented tibial component with modular metal augments was used in identical defects. All specimens were submitted to cyclical mechanical loading, during which cyclical and permanent tray displacement were determined. The results showed satisfactory stability with all the techniques except the bone bag method. Using metal augments gave the highest initial stability, but obviously lacked any potential for bone restoration

Aims. To evaluate the outcomes of cemented total hip arthroplasty (THA) following a fracture of the acetabulum, with evaluation of risk factors and comparison with a patient group with no history of fracture. . Patients and Methods. Between 1992 and 2016, 49 patients (33 male) with mean age of 57 years (25 to 87) underwent cemented THA at a mean of 6.5 years (0.1 to 25) following acetabular fracture. A total of 38 had undergone surgical fixation and 11 had been treated non-operatively; 13 patients died at a mean of 10.2 years after THA (0.6 to 19). Patients were assessed pre-operatively, at one year and at final follow-up (mean 9.1 years, 0.5 to 23) using the Oxford Hip Score (OHS). Implant survivorship was assessed. An age and gender-matched cohort of THAs performed for non-traumatic osteoarthritis (OA) or avascular necrosis (AVN) (n = 98) were used to compare complications and patient-reported outcome measures (PROMs). Results. The mean time from fracture to THA was significantly shorter for patients with AVN (2.2 years) or protrusio (2.2 years) than those with post-traumatic OA (9.4 years) or infection (8.0 years) (p = 0.03). Nine contained and four uncontained defects were managed with autograft (n = 11), bulk allograft (n = 1), or trabecular metal augment (n = 1). Initial fracture management (open reduction and internal fixation or non-operative), timing of THA (> /< one year), and age (> /< 55 years) had no significant effect on OHS or ten-year survival. Six THAs were revised at mean of 12 years (5 to 23) with ten-year all-cause survival of 92% (95% confidence interval 80.8 to 100). THA complication rates (all complications, heterotopic ossification, leg length discrepancy > 10 mm) were significantly higher following acetabular fracture compared with atraumatic OA/AVN and OHSs were inferior: one-year OHS (35.7 versus 40.2, p = 0.026); and final follow-up OHS (33.6 versus 40.9, p = 0.008). . Conclusion . Cemented THA is a reasonable option for the sequelae of acetabular fracture. Higher complication rates and poorer PROMs, compared with patients undergoing THA for atraumatic causes, reflects the complex nature of these cases. Cite this article: Bone Joint J 2017;99-B:1399–1408

The stemmed tibial implant has enabled the salvage of challenging situations of bone loss in primary knee arthroplasty. This ease of use has unfortunately led to the adoption of stemmed implants in situations where this may not be warranted. In general uncontained defects of less than 5 mm may be dealt with using cement fill techniques. Defect of less than 10mm require bone grafting techniques and those above 10 mm require stems and wedges. In the third category however long term results suggest that good results are only attainable in 65% of cases whether grafts or wedges are used. The use of intramedullary guides in this setting is re-addressed to allow the accurate placement of cuts enabling the use of pegged (or non-stemmed) implants. In addition with the advent of navigation this may be a special situation where non-stemmed implants may be selected over stemmed implants

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. Reconstructing acetabular defects in revision hip arthroplasty can be challenging. Small, contained defects can be successfully reconstructed with porous-coated cups without bone grafts. With larger uncontained defects, a cementless cup even with screws, will not engage with sufficient host bone to provide enough stability. Porous titanium augments were originally designed to be used with cementless porous titanium cups, and there is a scarcity of literature on their usage in cemented cups with bone grafting. Methods. We retrospectively reviewed five hips (four patients – 3 women, 1 man; mean age 65 years) in which we reconstructed the acetabulum with a titanium augment (Biomet, IN, USA) as a support for impaction bone grafting and cemented acetabular cups (Figure 1). All defects were classified according to Paprosky classification. Radiographic signs of osseointegration were graded according to Moore grading. Quality of life was measured with the Oxford Hip Score. Results. At a minimum of one year follow-up, none of the patients required any further surgery for aseptic loosening or re-revision. The Oxford Hip Scores generally improved and two of the patients were very satisfied with the overall outcome of the surgery and would have undergone the surgery again for a similar problem. The patient that underwent bilateral acetabular reconstruction during a period one month, scored lowered than the other patients and was less satisfied with the outcome. Radiographs at the latest follow-up revealed incorporation of the augment with mean change in acetabular component inclination of less than 1° and cup migration of less than 5 mm in both horizontal and vertical axes. Discussion. Acetabular reconstruction using porous titanium augments as a support for bone grafting and cemented acetabular cups can be an effective way of managing uncontained structural acetabular defect, with biocompatibility and osteoinducive characteristics. The early results are promising but longer follow-up is required

Object: To determine whether moderate bone loss in revision total knee arthroplasty can be corrected using an uncemented prosthesis combined with cancellous bone grafting. Methods and results: 23 revision total knee replacements for aseptic loosening or sepsis were undertaken by the senior author between May 1999 and August 2002. All cases involved bone loss of grades F2 and or T2 according to the Anderson Orthopaedic Research Institute Classification (Engh 1998). Bone loss was treated with a mixture of morselized autograft, morselized allograft and bone reamings loosely packed into any contained or uncontained defects following the technique of Whiteside (1992). Uncemented pros-theses with long contact bearing stems were then inserted. All 23 cases were able to partially weight bear immediately postoperatively, indicating satisfactory early press fit. No cases of loosening or cases suspicious of loosening have been noted. Of the 23 cases 19 have been followed for at least 1 year. 18/19 showed consolidation of bone defects and in 1 case there was significant bone resorption under the tibial base plate due to stress shielding. Conclusion: This technique is successful in building up moderate bone loss in revision total knee arthroplasty, therefore avoiding the need for excessive bone resection, large metal augments, mass allografts or custom prostheses

Introduction. The purpose of this study was to evaluate the mid-term clinical and radiological results in patients who were managed by double metal augmentations in proximal tibial uncontained bony defects undergoing primary or revision total knee arthroplasty. Materials and Methods. We performed double metal augmentations in proximal tibial uncontained bony defects undergoing total knee arthroplasty. Out of total 14 patients, 8 patients (4 priamry arthroplasty, 4 revision arthroplasty), mean 61.3 (50–80) years, were available for review at least 5 years follow up. The average follow up period was 86.3(60–99) months. Range of motion, American Knee Society Score were evaluated pre- and postoperatively as a clinical values. Another clinical assessments undertaken at the final reviews, Western Ontario and McMaster Universities osteoarthritis index (WOMAC), Oxford knee score (OKS), Short Form-36 (SF-36), Lower extremity functional scale (LEFS), and Lower extremity activity scale (LEAS) were checked. Radiological results, involving presence of radiolucent lines (RLLs) > 1mm in width, and osteolysis at the block-cement-bone interface were taken under fluoroscopic images at postoperatively and annually thereafter. Results. At the final follow-up, range of motion was increased from 97.5° to 121.3° and American Knee society score was significantly improved from 30.4 to 92.6 (p=0.03) and functional score from 43.1 to 86.9 (p=0.03). At the final follow-up, average WOMAC score was 10(2–20), OKS was 40.5(33–47), LEFS was 55.8(34–75), and LEAS was 10.9(7–15). There was no broken or deterioration sign at between first and second metal block at radiographically. RLLs at the block-cement-bone interfaces under fluoroscopic images were examined in 3 knees, but didn't cause any failure sign such as osteolysis, or collapse, or instability at final reviews. Conclusions. The clinical and radiological evaluations showed that the double metal augmentations is a favorable and useful way to manage severe uncontained proximal tibial bony defects at least 5 years mid-term follow up period. Preoperative standing anteroposterior (AP) radiograph (Fig 1) shows severe uncontained proximal tibial bone defects, approximately 23 mm compared with unaffected lateral tibial condyle. AP view of fluoroscopy with medial double metal blocks (10 mm block + down sized 10 mm block) combined intramedullary stem at 60-month follow-up after primary total knee arthroplasty, demonstrating radiolucent line (white arrow) of 2.5 mm width bottom the block (Fig 2). AP view at 92-month follow-up indicating non-progressive stable radiolucent lines (white arrow) at same area without any radiographic failure signs and broken sign between first and second metal block (Fig 3)

Massive uncontained glenoid defects are a difficult surgical problem requiring reconstruction in the setting of either primary or revision total shoulder arthroplasty. Our aim is to present a new one-stage technique that has been developed in our institution for glenoid reconstruction in the setting of massive uncontained glenoid bone loss. We utilise a modified delto-pectoral approach to perform our dual biology allograft autograft glenoid reconstruction. The native glenoid and proximal femoral allograft are prepared and shaped to create a precisely matched contact surface, which permits axial compression to secure fixation. The surface of the glenoid is lateralised to at least the level of the coracoid. The central cancellous femoral allograft is removed and impaction autografting is performed prior to implantation of a glenoid base plate with 25-mm long centre peg. Two screws are inserted into the best quality native scapular bone available to ensure compression. A reverse shoulder arthroplasty is implanted. We have performed our dual-biology reconstruction of the glenoid in combination with reverse total shoulder arthroplasty in 8 patients to date. The technique has been performed in the setting of massive uncontained glenoid defects without prostheses as well as in revisions from failed hemiarthroplasties and total shoulder arthroplasties. Our post-operative follow-up is now up to 32 months. CT scanning as early as 6 months demonstrates incorporation of the graft. There has been no evidence of loosening. None of our cases have been complicated by infection or peri-prosthetic fracture and there have been no dislocations. One patient sustained an acromial stress fracture at 9 months post-operatively after lifting a 100-pound gas cylinder. This was diagnosed on bone scan, had no impact on the construct and was managed in a sling for comfort. Another patient has developed Nerot grade I notching which substantially in all patients, with an average improvement of 6.6 on a 10-point scale. Our dual biology allograft-autograft reconstruction is a useful and elegant technique in the setting of massive uncontained defects of the glenoid, which permits the implantation of a reverse total shoulder arthroplasty. We believe this technique to be reproducible and uses materials that are both readily available and familiar

The properties of impacted morsellised bone graft (MBG) in revision total knee arthroplasty (TKA) were studied in 12 horses. The left hind metatarsophalangeal joint was replaced by a human TKA. The horses were then randomly divided into graft and control groups. In the graft group, a unicondylar, lateral uncontained defect was created in the third metatarsal bone and reconstructed using autologous MBG before cementing the TKA. In the control group, a cemented TKA was implanted without the bone resection and grafting procedure. After four to eight months, the animals were killed and a biomechanical loading test was performed with a cyclic load equivalent to the horse’s body-weight to study mechanical stability. After removal of the prosthesis, the distal third metatarsal bone was studied radiologically, histologically and by quantitative and micro CT. Biomechanical testing showed that the differences in deformation between the graft and the control condyles were not significant for either elastic or time-dependent deformations. The differences in bone mineral density (BMD) between the graft and the control condyles were not significant. The BMD of the MBG was significantly lower than that in the other regions in the same limb. Micro CT showed a significant difference in the degree of anisotropy between the graft and host bone, even although the structure of the area of the MBG had trabecular orientation in the direction of the axial load. Histological analysis revealed that all the grafts were revascularised and completely incorporated into a new trabecular structure with few or no remnants of graft. Our study provides a basis for the clinical application of this technique with MBG in revision TKA

The goals of revision arthroplasty of the hip are to restore the anatomy and achieve stable fixation for new acetabular and femoral components. It is important to restore bone stock, thereby creating an environment for stable fixation for the new components. The bone defects encountered in revision arthroplasty of the hip can be classified either as contained (cavitary) or uncontained (segmental). Contained defects on both the acetabular and femoral sides can be addressed by morselised bone graft that is compacted into the defect. Severe uncontained defects are more of a problem particularly on the acetabular side where bypass fixation such as distal fixation on the femoral side is not really an alternative. Most authors agree that the use of morselised allograft bone for contained defects is the treatment of choice as long as stable fixation of the acetabular component can be achieved and there is a reasonable amount of contact with bleeding host bone for eventual ingrowth and stabilisation of the cup. On the femoral side, contained defects can be addressed with impaction grafting for very young patients or bypass fixation in the diaphysis of the femur using more extensively coated femoral components or taper devices. Segmental defects on the acetabular side have been addressed with structural allografts for the past 15 to 20 years. These are indicated in younger individuals with Type 3A defects. Structural grafts are unsuccessful in Type 3B defects. Alternatives to the structural allografts are now being utilised with shorter but encouraging results in most multiply operated hips with bone loss. New porous metals such as trabecular metal (tantalum), which has a high porosity similar to trabecular bone and also has a high coefficient of friction, provide excellent initial stability. The porosity provides a very favorable environment for bone ingrowth and bone graft remodeling. Porous metal acetabular components are now more commonly used when there is limited contact with bleeding host bone. Porous metal augments of all sizes are being used instead of structural allografts in most situations. On the femoral side, metaphyseal bone loss, whether contained or uncontained, is most often addressed by diaphyseal fixation with long porous or tapered implants, modular if necessary. Distal fixation requires at least 4 centimeters of diaphyseal bone and in Type IV femurs, a choice must be made between a mega prosthesis or a proximal femoral allograft. The proximal femoral allograft can restore bone stock for future surgery in younger patients. The mega prosthesis which is more appropriate in the older population may require total femoral replacement if there is not enough diaphyseal bone for distal fixation with cement. Cortical struts are used for circumferential diaphyseal bone defects to stabilise proximal femoral allografts, to bypass stress risers and to serve as a biological plate for stabilising peri-prosthetic fractures

Aim: To determine whether moderate bone loss in revision total knee arthroplasty can be corrected using an uncemented prosthesis combined with cancellous bone grafting. Methods and Patients: 40 revision total knee replacements were undertaken by the senior author between May 1999 and June 2004. 27 one stage revisions for aseptic loosening and 13 two stage revisions for infection. All cases involved bone loss of grades F1/2 and or T1/2 according to the Anderson Orthopaedic Research Institute Classification (Engh 1998). Bone loss was treated with a mixture of morselized autograft, morselized allograft and bone reamings loosely packed into any contained or uncontained defects following the technique of Whiteside (1992). Uncemented prostheses with long contact bearing stems were then inserted. Patients were followed up prospectively with Oxford and HSS knee scores. Results: All 40 cases were able to partially weight bear immediately postoperatively, indicating satisfactory early press fit. No cases of loosening or cases suspicious of loosening have been noted. Mean follow up of 37 months with no patients requiring re revision, no persistent stem pain and no infection in the one stage revisions. 2 cases of infection in the 2 stage group are discussed, neither have required implant removal. Intraoperative and postoperative complications are discussed as well as range of motion, pain and patient satisfaction. In 39/40 cases bone stock has been restored. In 1 case there was significant bone resorption under the tibial base plate due to stress shielding. Conclusions: This technique is successful in building up moderate bone loss in revision total knee arthroplasty, therefore avoiding the need for excessive bone resection, large metal augments, mass allografts or custom made prostheses

Introduction: To evaluate the medium-term outcome of patients undergoing revision knee arthroplasty with structural allograft for uncontained defects. Methods: We followed prospectively 50 patients undergoing 52 revision knee replacements with 66 structural grafts in three institutions. An independent investigator reviewed twenty-nine knees in 27 patients after a mean of 96.9 months. Results: Twelve knees were re-revised at a mean of 70.7 months. Two of these patients retained their allografts. Eleven patients died with their structural allograft and implants intact and were not awaiting revision at a mean of 93 months. Failure was defined as an increase of less than 20 points in the modified HSS knee score at the time of the review or the need for an additional operation related to the allograft. Thirteen knees were deemed to be failures giving a 75% success rate. Graft resorption occurred in five patients resulting in implant loosening. Four failed due to infection and non-union between the host bone and allograft was present in two. One patient with both knees grafted failed to gain a 20-point improvement. Survival analysis showed a 72% survival at 10 years. Clinically, the modified HSS score improved from a mean of 32.5 pre-operatively to 75.6 at the time of the review. Radiographic analysis of the surviving grafts showed no severe resorption, one moderate and two mild cases of resorption. Evaluation for loosening revealed one patient with a loose tibial component, while three patients had non-progressive tibial radiolucent lines. All four patients were asymptomatic. Conclusions: Our results demonstrated encouraging medium-term survival of allografts utilised for revision knee replacement in a group of difficult patients with massive bone loss

We used a biodegradable mesh to convert an acetabular defect into a contained defect in six patients at total hip replacement. Their mean age was 61 years (46 to 69). The mean follow-up was 32 months (19 to 50). Before clinical use, the strength retention and hydrolytic in vitro degradation properties of the implants were studied in the laboratory over a two-year period. A successful clinical outcome was determined by the radiological findings and the Harris hip score. All the patients had a satisfactory outcome and no mechanical failures or other complications were observed. No protrusion of any of the impacted grafts was observed beyond the mesh. According to our preliminary laboratory and clinical results the biodegradable mesh is suitable for augmenting uncontained acetabular defects in which the primary stability of the implanted acetabular component is provided by the host bone. In the case of defects of the acetabular floor this new application provides a safe method of preventing graft material from protruding excessively into the pelvis and the mesh seems to tolerate bone-impaction grafting in selected patients with primary and revision total hip replacement

Because there are a number of complicating factors, total hip arthroplasty (THA) performed following acetabular fractures has a less favourable prognosis than when done for primary degenerative arthritis. Patients who have had ace-tabular fracture and present for consideration of THA need careful clinical and radiological assessment. Investigation should include AP and lateral radiographs, 45° inlet/outlet views, obturator and iliac obliques, Judet views and CT scan, with or without 3D reconstruction. There are various classifications defining whether the bone deficiency is contained or uncontained and the extent of the structural defect. Treatment options include autograft, allograft together with mesh, screws, plates, rings, cages, etc. It is probably preferable to undertake THA sooner (as soon as there is radiological evidence of incongruent articular surfaces) rather than later, as this reduces the delay between fracture and recovery from THA, and any inadequate reduction can be minimised or corrected. The surgical approach must allow adequate access for the intended reconstruction. Small contained or uncontained defects can be treated with cemented or cementless implants and limited grafting. Large defects require structural reinforcement, bone grafting, a retaining cage and, unless a custom-made implant is used, cemented fixation. Potential problems at the time of surgery include sciatic nerve injury (beware the ‘double crush syndrome’) obstructive hardware, heterotopic ossification, avascular necrosis of the acetabulum and occult infection. Patients who are elderly or who present with markedly impacted fracture, extensive abrasion or fracture of the femoral head, displaced femoral neck fracture, and extensive acetabular comminution in the presence of osteopoenic bone, may warrant acute management with THA. Early experience of THA in the treatment of selected acute fractures is encouraging. However, the clinical results of THA after fractures of the acetabulum are often disappointing, and there is no current evidence that open reduction and internal fixation improves the success of the subsequent THA. THA following acetabular fractures is a challenging procedure with a high complication rate. Appropriate investigation and preoperative planning reduces the risk of complications

Bone loss can be treated in one of two general ways. Missing bone can be replaced either with bone graft applied to the host bone or augmentations attached to the revision implants. The ideal treatment of bone defects during revision TKR surgery: 1) makes immediate full weight bearing possible; 2) provides longterm support for the implants; 3) Restores original bone stock. Bone grafts achieve these goals when the defects are CAVITARY. Therefore, bone grafts rather than metal augmentation devices are the surgical treatment of choice when these types of defects are encountered during revision TKR surgery. Although bone grafts may achieve these goals when the defects are SEGMENTAL, the results are uncertain and more difficult to achieve. Metal augmentations make possible immediate full weight bearing and provide reliable long-term support for revision TKR implants. When these augments are made of Tantalulm, a metal with 80% porosity, the restoration of bone stock is also possible. There are advantages and drawbacks to each approach. The advantages of bone grafts are that they: 1) restore bone stock; 2) are relatively inexpensive (especially if autogenous graft is used); 3) can be applied with relatively simple instrumentation; and 4) allow defects of a wide variety of sizes and shapes to be treated. The disadvantages of bone grafts are that they: 1) have limited application in large, segmental defects where structural support is necessary; 2) do not always unite predictably, particularly when the host bone is osteopenic or when angular deformities exist; 3) are shaped and inserted without the benefit of precise instrumentation; and 4) may require limited weight bearing or restricted activity for a period of time following surgery. The advantages of augmentation devices are that they: 1) can be manufactured in a wide variety of shapes and sizes; 2) provide immediate stable fixation; and 3) can be inserted using precise cutting instruments. Therefore, the indications for metal augmentation devices are: 1) uncontained defects (segmental) that require structural support for the knee implant; 2) knees with osteopenic bone or large angular defects; and 3) older patients in whom the importance of immediate mobilization and unrestricted weight-bearing is more important than the restoration of bone stock

The principles of acetabular reconstruction include the creation of a stable acetabular bed, secure prosthetic fixation with freedom of orientation, bony reconstitution, and the restoration of a normal hip centre of rotation with acceptable biomechanics. Acetabular impaction grafting, particularly with cemented implants, has been shown to be a reliable means of acetabular revision. Whilst our practice is heavily weighted towards cementless revision of the acetabulum with impaction grafting, there is a large body of evidence from Tom Slooff and his successors that cemented revision with impaction grafting undertaken with strict attention to technical detail is associated with excellent long terms results in all ages and across a number of underlying pathologies including dysplasia and rheumatoid arthritis. We use revision to a cementless hemispherical porous-coated acetabular cup for most isolated cavitary or segmental defects and for many combined deficiencies. Morsellised allograft is packed in using chips of varied size and a combination of impaction and reverse reaming is used in order to create a hemisphere. There is increasing evidence for the use of synthetic grafts, usually mixed with allograft, in this setting. The reconstruction relies on the ability to achieve biological fixation of the component to the underlying host bone. This requires intimate host bone contact, and rigid implant stability. It is important to achieve host bone contact in a least part of the dome and posterior column – when this is possible, and particularly when there is a good rim fit, we have not found it absolutely necessary to have contact with host bone over 50% of the surface. Once the decision to attempt a cementless reconstruction is made, hemispherical reamers are used to prepare the acetabular cavity. Sequentially larger reamers are used until there is three-point contact with the ilium, ischium and pubis. Acetabular reaming should be performed in the desired orientation of the final implant, with approximately 200 of anteversion and 400 of abduction (or lateral opening). Removing residual posterior column bone should be avoided. Reaming to bleeding bone is desirable. Morsellised allograft is inserted and packed and/or reverse reamed into any cavitary defects. This method can also be applied to medial wall uncontained defects by placing the graft onto the medial membrane or obturator internus muscle, and gently packing it down before inserting the cementless acetabular component. Either the reamer heads or trial cups can be used to trial prior to choosing and inserting the definitive implant. The fixation is augmented with screws in all cases. Incorporation of the graft may be helped by the use of autologous bone marrow. Cementless acetabular components with impaction grafting should not be used when the host biology does not allow for stability or for bone ingrowth. This includes the severely osteopenic pelvis, pelvic osteonecrosis after irradiation, tumours, and metabolic bone disorders. They should also not be used in the presence of pelvic discontinuity unless the structure of the pelvic ring has been restored with a plate, or specialised materials/porous metals are used. The challenge of reconstituting the acetabulum depends on the degree and type of bone loss. The principles of maximising host bone-implant contact and implant stability have borne fruit in our experience with cementless revision. The advantages of bone grafting in acetabular reconstruction include the ability to restore bone stock, to rebuild a normal hip center and hip biomechanics and to increase bone stock for future revisions