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

Aims. The use of a porous metal shell supported by two augments with the ‘footing’ technique is one solution to manage Paprosky IIIB acetabular defects in revision total hip arthroplasty. The aim of this study was to assess the medium-term implant survival and radiological and clinical outcomes of this technique. Methods. We undertook a retrospective, two-centre series of 39 hips in 39 patients (15 male, 24 female) treated with the ‘footing’ technique for Paprosky IIIB acetabular defects between 2007 and 2020. The median age at the time of surgery was 64.4 years (interquartile range (IQR) 54.4 to 71.0). The median follow-up was 3.9 years (IQR 3.1 to 7.0). Results. The cumulative medium-term survival of the acetabular construct was 89%. Two hips (5.1%) required further revision due to shell loosening, one hip (2.6%) due to shell dislocation, and one hip (2.6%) due to infection. The median Harris Hip Score improved significantly from 47 points (IQR 41.5 to 54.9) preoperatively to 80 points (IQR 73.5 to 88.6) at the latest follow-up (p < 0.001). Conclusion. The reconstruction of Paprosky IIIB acetabular defects with porous tantalum shells and two augments using the ‘footing’ technique showed excellent medium-term results. It is a viable option for treating these challenging defects. Cite this article: Bone Joint J 2024;106-B(5 Supple B):54–58

Aims. The advent of trabecular metal (TM) augments has revolutionized the management of severe bone defects during acetabular reconstruction. The purpose of this study was to evaluate patients undergoing revision total hip arthroplasty (THA) with the use of TM augments for reconstruction of Paprosky IIIA and IIIB defects. Patients and Methods. A retrospective study was conducted at four centres between August 2008 and January 2015. Patients treated with TM augments and TM shell for a Paprosky grade IIIA or IIIB defect, in the absence of pelvic discontinuity, and who underwent revision hip arthroplasty with the use of TM augments were included in the study. A total of 41 patients with minimum follow-up of two years were included and evaluated using intention-to-treat analysis. Results. There were 36 (87.8%) patients with a Paprosky IIIA defect and five (12.2%) patients with a Paprosky IIIB defect. The mean age was 56.7 years (28 to 94). There were 21 (51.2%) women and 20 (48.8%) men. The mean follow-up was 39.4 months (12 to 96). One (2%) patient died after eight years. No failures were noted in the series. The mean survivorship was 100% at the time of latest follow-up. Conclusion. The results of this multicentre study showed encouraging short- and mid-term results for the use of TM augments in the management of Paprosky grade IIIA and IIIB defects. Cite this article: Bone Joint J 2018;100-B:903–8

The management of severe acetabular bone defects poses a complex challenge in revision hip arthroplasty. Although biological fixation materials are currently dominant, cage has played an important role in complex acetabular revision in the past decades, especially when a biological prosthesis is not available. The purpose of this study is to report the long-term clinical and radiographic results of Paprosky type Ⅲ acetabular bone defects revised with cage and morselized allografts. We retrospectively analyzed 45 patients who underwent revision hip arthroplasty with cage and morselized allografts between January 2007 and January 2019. Forty-three patients were followed up. There were 19 Paprosky type IIIA bone defect patients and 24 Paprosky type IIIB bone defect patients and 7 patients of the 24 were also with pelvic discontinuity. Clinical assessment included Harris Hip Score (HHS) and Short Form-12 (SF-12). Radiographic assessment included cage stability, allografts incorporation, and center of rotation. All patients were followed up with a mean follow-up of 10.6 years, HHS and SF-12 improved significantly at last follow-up in comparison to the preoperative. There were 2 re-revisions, one at 5 years after surgery, another at 13.6 years after surgery. Two patients had nonprogressive radiolucency in zone III and the junction of zone II and zone III at the bone implant interface. Allografts of 40 (93%) cases incorporated fully. The combination of cage and morselized allograft is an alternative option for acetabular revision with Paprosky type III bone defects with satisfactory long-term follow-up results

Aims. The aim of this study was to examine the implant accuracy of custom-made partial pelvis replacements (PPRs) in revision total hip arthroplasty (rTHA). Custom-made implants offer an option to achieve a reconstruction in cases with severe acetabular bone loss. By analyzing implant deviation in CT and radiograph imaging and correlating early clinical complications, we aimed to optimize the usage of custom-made implants. Methods. A consecutive series of 45 (2014 to 2019) PPRs for Paprosky III defects at rTHA were analyzed comparing the preoperative planning CT scans used to manufacture the implants with postoperative CT scans and radiographs. The anteversion (AV), inclination (IC), deviation from the preoperatively planned implant position, and deviation of the centre of rotation (COR) were explored. Early postoperative complications were recorded, and factors for malpositioning were sought. The mean follow-up was 30 months (SD 19; 6 to 74), with four patients lost to follow-up. Results. Mean CT defined discrepancy (Δ) between planned and achieved AV and IC was 4.5° (SD 3°; 0° to 12°) and 4° (SD 3.5°; 1° to 12°), respectively. Malpositioning (Δ > 10°) occurred in five hips (10.6%). Native COR reconstruction was planned in 42 cases (93%), and the mean 3D deviation vector was 15.5 mm (SD 8.5; 4 to 35). There was no significant influence in malpositioning found for femoral stem retention, surgical approach, or fixation method. Conclusion. At short-term follow-up, we found that PPR offers a viable solution for rTHA in cases with massive acetabular bone loss, as highly accurate positioning can be accomplished with meticulous planning, achieving anatomical reconstruction. Accuracy of achieved placement contributed to reduced complications with no injury to vital structures by screw fixation. Cite this article: Bone Joint J 2022;104-B(10):1110–1117

The use of trabecular metal (TM.) shells supported by two TM augments in the footing technique has been described as a potential option for the treatment of Paprosky 3B acetabular defects. The aim of this study was to assess the mid implant survivorship and radiological and clinical outcomes after acetabular revision using this technique. We undertook a retrospective, double-centre series of 39 hips in 39 patients (15 male, 24 female) treated with the footing technique using a TM shell supported by two TM augments, for severe acetabular bone loss between 2007 and 2020. The mean age at the time of surgery was 62,9 (28 to 86) years. The mean follow-up was 5,4 (1,5 to 15) years. The cumulative mid survivorship of the implant with revision for any cause was 89%. 3 hips (7,6%) required further revision due to aseptic loosening, and 1 (2,8%) required revision for infection. The mean Harris Hip Score improved significantly from 48 (29 to 65) preoperatively to 79 points (62 to 98) at the latest follow-up (p < 0.001). The reconstruction of Paprosky 3B acetabular defects with TM shells and two augments in footing-technique showed excellent mid-term results. This technique appears to be a viable option for treating these defects

Aims. The purpose of this retrospective study was to evaluate the minimum five-year outcome of revision total hip arthroplasty (THA) using the Kerboull acetabular reinforcement device (KARD) in patients with Paprosky type III acetabular defects and destruction of the inferior margin of the acetabulum. Patients and Methods. We identified 36 patients (37 hips) who underwent revision THA under these circumstances using the KARD, fresh frozen allograft femoral heads, and reconstruction of the inferior margin of the acetabulum. The Merle d’Aubigné system was used for clinical assessment. Serial anteroposterior pelvic radiographs were used to assess migration of the acetabular component. Results. At a mean follow-up of 8.2 years (5 to 19.3), the mean Merle d’Aubigné score increased from 12.5 (5 to 18) preoperatively to 16.5 (10 to 18) (p < 0.0001). The survival rate at ten years was 95.3% (. sd. 4.5; 95% confidence interval (CI) 86.4 to 100) and 76.5% (. sd. 9.9, 95% CI 57.0 to 95.9) using aseptic loosening and radiological loosening as the endpoints, respectively. Conclusion. These results show that the use of the KARD with reconstruction of the inferior margin of the acetabulum in revision THA is associated with acceptable clinical results and survival at mid-term follow-up with, however, a high rate of migration of the acetabular component of 21.6%. Cite this article: Bone Joint J 2018;100-B:725–32

The advent of trabecular metal (TM) augments has revolutionized the management of severe bone defects during acetabular reconstruction. The purpose of this study was to evaluate patients undergoing revision total hip arthroplasty (THA) with the use of TM augments for reconstruction of Paprosky 3A, 3B defects and defects associated with pelvic discontinuity. A retrospective study was conducted of the cases performed at four centers between August 2007 and January 2015. Patients treated with TM augments for Paprosky 3A, 3B or chronic pelvic discontinuity were included in the study. All surgeries were performed through a posterior approach. A total of 57 patients (Male 34 (69%), Female 23(31%)), mean age 54 years (range, 28–94 years), with minimum follow up of one-year were included and evaluated using intention to treat analysis. There were 44 (77%) patients with a 3A defect, 11(19%) patients with a 3B defect (6 had an associated pelvic discontinuity), and 2 (3.5%) with a 2C defect and associated pelvic discontinuity. The mean follow-up was 37 months (range, 12–96 months). One (2%) patient died after 8 years of unrelated causes. Three (5.5%) patients had acetabular component loosening requiring revision; Two failures were (3.5%) due to aseptic loosening and one (2%) due to septic loosening. Fifty-four patients had a radiologically stable integration of the components at latest follow-up - survivorship was 94.7%. The results of this multi-center study demonstrate encouraging short and mid-term results for the use of TM augments in the management of Grade 3A and 3B defects, and defects associated with a chronic pelvic discontinuity

Introduction. Acetabular revision surgery remains a technically demanding procedure with higher failure rates than primary total hip arthroplasty (THA). An acetabular component with three dimensional porous titanium and anatomic screw holes (Figure 1) was designed to allow the cup to be positioned anatomically and provide reliable fixation. Methods. A prospective multicenter study of 193 cases (190 patients) was conducted to assess the midterm clinical outcomes of the revision titanium acetabular shell. Radiographs, demographics, Harris Hip Score (HHS), and Short Form 36 (SF-36) were collected preoperatively, at 6 weeks, 3 months, and annually thereafter to 5 years. The mean duration of follow-up was 3.36 years. The Paprosky classification was assessed intraoperatively. Short Form 6D (SF-6D) utility values were obtained by transforming SF-36 scores through the Brazier method and were analyzed for effect size. Results. At time of surgery, mean patient age was 63.5 years and mean BMI was 28.1. 69 of the 193 cases were graded as 3A or 3B according to the Paprosky classification method. For all cases, Harris Hip Scores improved significantly (p < 0.001) from a preoperative mean score of 53.60 to a mean score of 86.15 at 1 year. These significant gains were maintained through 5 years, with a mean score of 87.35 at the 5-year time point. The Harris Hip Scores for Paprosky 3A and 3B cases also improved significantly (p < 0.001) from a preoperative mean score of 48.11 to a mean score of 85.45 at 1 year. These significant gains were maintained through 5 years, with a mean score of 85.65 at the 5-year time point. Among the radiographs independently reviewed to date, no cup migration or unstable cups have been identified. There were 12 acetabular shell re-revisions reported, for infection (7), aseptic loosening (4) and recurrent dislocation (1). Three of the cases revised for aseptic loosening were Paprosky type 3A, and one was 3B. For all cases, a clinically significant improvement in health utility was achieved by 3 months postoperative, with an effect size of 0.54. Clinically significant scores were maintained throughout the follow-up period, reaching an effect size of 0.64 at 5 years. Effect sizes were larger for cases with Paprosky classifications of 3A and 3B than the overall study population at all time points, reaching clinical significance at 3 months with an effect size of 0.64, and continuing to increase to an effect size of 1.19 at 5 years. Conclusion. Even in patients with severe acetabular defects, next generation highly porous acetabular components with three dimensional porous titanium and anatomic screw holes provide excellent stability, predictable midterm biologic fixation, pain, and reduction, and improved clinical function and health utility

We report the results of 62 hips in 62 patients (17 males, 45 females) with mean age of 62.4 years (37 to 81), who underwent revision of the acetabular component of a total hip replacement due to aseptic loosening between May 2003 and November 2007. All hips had a Paprosky type IIIa acetabular defect. Acetabular revision was undertaken using a Procotyl E cementless oblong implant with modular side plates and a hook combined with impaction allografting. . At a mean follow-up of 60.5 months (36 to 94) with no patients lost to follow-up and one died due to unrelated illness, the complication rate was 38.7%. Complications included aseptic loosening (19 hips), deep infection (3 hips), broken hook and side plate (one hip) and a femoral nerve palsy (one hip). Further revision of the acetabular component was required in 18 hips (29.0%) and a further four hips (6.4%) are currently loose and awaiting revision. . We observed unacceptably high rates of complication and failure in our group of patients and cannot recommend this implant or technique

Introduction. Different classification systems for acetabular deficiencies, including AAOS and Paprosky, are commonly used. Classification of these bone defects is often performed based on Xrays or CT images. Although the amount of bone loss is rarely measured quantitatively in these images, objective and quantitative data on the degree of bone loss could facilitate correct and consistent classification. Recently, a computerized CT-based tool was presented to quantitatively asses bone loss: TrABL (Total radial Acetabular Bone Loss). This study demonstrates on an extended patient population that TrABL combined with standard classification systems provides more detailed, quantitative information on bone defects. Methods. CT scans of 30 severe acetabular defects, classified Paprosky IIIA and IIIB, were collected and analysed with TrABL. The tool automatically calculated the total amount of bone that was missing around the acetabulum, seen from the hip's original rotation centre. Six anatomical regions were defined for which the degree of bone loss was expressed: anterosuperior, anteroinferior, inferior, posteroinferior, posterosuperior and medial. Results. Statistical analysis highlighted that total bone loss was highest in the posterosuperior region (63%±27%). Bone loss was lowest inferiorly. No statistical differences were found between the anterosuperior, anteroinferior, posteroinferior, and medial regions. The majority of the defects suffered at least 25% bone loss in more than half of the regions. All defects had at least one region with the same degree of bone loss. The quantitative 3D data of TrABL provided more information compared to general classification schemes. This information has shown to be crucial during implant selection and preoperative planning for multiple clinical cases. Conclusion. Classification of acetabular bone deficiencies into existing systems can be refined by the quantitative data provided by TrABL. As a result, the ease and consistency regarding the treatment selection for particular categories of challenging defects will increase

One of the many challenges in revision hip arthroplasty is massive bone loss. Subsidence of the collarless stem with impaction allografting has been reported by several authors. Impaction grafting has emerged as a useful technique in the armamentarium of the revision total hip arthroplasty surgeon. The original technique proposed by Ling has been associated with complications, including femoral shaft fractures, recurrent dislocations, and uncontrolled component subsidence. Modifications in that technique seem to be associated with a reduction in complications. The aim of this study was to assess the functional outcome of radial impaction grafting in femoral bone defects and the use of collared long stem prosthesis. A total of 107 patients underwent radial impaction allografting and collared long stem prosthesis during revision THA between 1997 and 2005. The patients with Paprosky type II, IIIA and IIIB defects were included in this study. Average duration between the primary and revision surgery was 9.4 years (Range 6–23 years). Assessment was done using Oxford Hip Score, Harris Hip Score and with plain X-rays. Three patients were lost to follow-up and three patients died due to unrelated causes. The follow-up period lasted between 12 to 114 months (average – 68.8 months). Three patients who sustained post-operative peri-prosthetic fracture had standard stem inserted in them. None of the patients with long stem sustained peri-prosthetic fracture. Four patients had infection and underwent revision procedure. In this study, using revision for any cause as the end-point, survival of the femoral stem was 93.8%. Subsidence was not recorded in any of the patients in this study. Oxford Hip Score improved from mean pre-operative value of 41.2 to 19.2 post-operatively. Mean Harris Hip Score improved from 40.8 pre-operatively to 83.4 post-operatively. Subsidence of the prosthesis is commonly encountered with collarless stems and this was not a problem in this study. The risk of peri-prosthetic fracture can be reduced by using long stem prosthesis which bypasses the existing cement mantle by at least two femoral diameters. The radial impaction grafting technique permits the use of revision femoral components with variable stem lengths, neck lengths, and neck offsets. We conclude that radial imaction graftind along with collared long stem prosthesis is a good solution for massive femoral bone defects while performing total hip arthroplasty

Introduction

As population grows older, and patients receive primary joint replacements at younger age, more and more patients receive a total hip prosthesis nowadays. Ten-year failure rates of revision hip replacements are estimated at 25.6%. The acetabular component is involved in over 58% of those failures. From the second revision on, the pelvic bone stock is significantly reduced and any standard device proves inadequate in the long term [Villanueva et al. 2008]. To deal with these challenges, a custom approach could prove valuable [Deboer et al. 2007].

If a surgeon is faced with altered lesser trochanter anatomy when revising the femoral component in revision total hip replacement, a peri-prosthetic fracture, or Paprosky type IIIb or type IV femoral bone loss, a modular tapered stem offers the advantages of accurately controlling femoral version and length. The splines of the taper allow rotational control, and improve the fit in femoral canals with diaphyseal bone loss. In general, two centimetres of diaphyseal contact is all that is needed to gain stability with modular tapered stems. By allowing the proximal body trial to rotate on a well-fixed distal segment during trial reduction, appropriate anteversion can be obtained in order to improve intra-operative stability, and decrease the dislocation risk. However, modular stems should not be used for all femoral revisions, as implant fracture and corrosion at modular junctions can still occur. Cite this article: Bone Joint J 2013;95-B, Supple A:95–7

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

Acetabular bone loss is a challenging problem facing the revision total hip replacement surgeon. Reconstruction of the acetabulum depends on the presence of anterosuperior and posteroinferior pelvic column support for component fixation and stability. The Paprosky classification is most commonly used when determining the location and degree of acetabular bone loss. Augments serve the function of either providing primary construct stability or supplementary fixation. . When a pelvic discontinuity is encountered we advocate the use of an acetabular distraction technique with a jumbo cup and modular porous metal acetabular augments for the treatment of severe acetabular bone loss and associated chronic pelvic discontinuity. Cite this article: Bone Joint J 2014;96-B(11 Suppl A):36–42

Acetabular distraction for the treatment of chronic pelvic discontinuity was first described by Sporer and Paprosky. The authors advocate the posterolateral approach for exposure of the posterior ilium and posterior column, The patient is secured in the lateral decubitus position. Following a systematic approach to surgical exposure, acetabular component removal should be performed with “cup out” osteotomes resulting in minimal iatrogenic bone loss. Following component removal and confirmation of a chronic discontinuity determine the integrity of the remaining AS and PI columns. If porous metal augments are needed for primary stabilization, the augments are placed prior to cup insertion for reconstruction of the AS and/or PI column. Next, Kirschner (K) wires (size 2.4) are placed in the remaining AS and PI bone so that the distractor can be secured in an extra-acetabular position. The distractor is placed over the K-wires allowing for lateral or peripheral acetabular distraction and resultant medial or central compression at the discontinuity. With the distractor in an extra-acetabular position, hemispherical reamers are used until an interference fit is achieved between the native or augmented AS and PI columns. The acetabulum should be reamed on reverse to avoid excessive removal of host bone. When the proper acetabular component size has been reached, the reamer will disengage from the reamer handle and the reamer can be used as a surrogate acetabular shell; when the acetabulum is maximally distracted, the entire construct will move as a unit. Crushed cancellous allograft is used to bone graft the discontinuity and reamed on reverse. A revision tantalum cup is inserted with continual distraction using the distractor. Cement is applied to the augment surface prior to cup insertion in order to utilise the construct. Following cup insertion, the distractor and K-wires are removed. Adjuvant screw fixation is performed, with a minimum of 4 screws, and placing at least one of the screws inferiorly for fixation in the superior public ramus or ischium to prevent abduction failure of the construct. In the setting of severely osteoporotic bone and inadequate screw fixation, an augment placed posterosuperiorly can be used for supplemental fixation. This augment is also unitised to the cup with cement at the same time as the liner is cemented into the cup. Bone wax is placed over the exposed tantalum surface of the posterosuperior augment to minimise soft-tissue ingrowth into the augment

Revision of the failed femoral component can be challenging. Multiple reconstructive options are available and the procedure is technically difficult and thus meticulous pre-operative planning is required. The Paprosky Femoral Classification is useful as it helps the surgeon determine what bone stock is available for fixation and hence, which type of femoral reconstruction is most appropriate. Type 1 Defect: This is essentially a normal femur and reconstruction can proceed as the surgeon would with a primary femur. Type 2 Defect: The metaphysis is damaged but still supportive and hence a stem that gains primary fixation in the metaphysis can be used. Type 3 Defect: The metaphysis is damaged and non-supportive and hence a stem that gains primary fixation in the diaphysis is required. Broken down into types “A” and “B” based on the amount of intact isthmus available for distal fixation. Type 3A Defect: >4 cm of intact femoral isthmus is present. Can be managed with a fully porous coated stem, so long as the diameter is <18 mm and torsional remodeling is not present. Type 3B Defect: There is < 4 cm of intact femoral isthmus and based on lower rates of osseointegration if a fully porous coated stem is used, a modular titanium tapered stem is recommended. Type 4 Defect: The most challenging to manage as there is no isthmus available for distal fixation. Can be managed with proximal femoral replacement if uncontained and impaction grafting if contained. We have also successfully used modular titanium tapered stems that appear to gain “3-point fixation” in this type of defect

Aims. Bone stock restoration of acetabular bone defects using impaction bone grafting (IBG) in total hip arthroplasty may facilitate future re-revision in the event of failure of the reconstruction. We hypothesized that the acetabular bone defect during re-revision surgery after IBG was smaller than during the previous revision surgery. The clinical and radiological results of re-revisions with repeated use of IBG were also analyzed. Methods. In a series of 382 acetabular revisions using IBG and a cemented component, 45 hips (45 patients) that had failed due to aseptic loosening were re-revised between 1992 and 2016. Acetabular bone defects graded according to Paprosky during the first and the re-revision surgery were compared. Clinical and radiological findings were analyzed over time. Survival analysis was performed using a competing risk analysis. Results. Intraoperative bone defect during the initial revision included 19 Paprosky type IIIA and 29 Paprosky type IIIB hips; at re-revision, seven hips were Paprosky type II, 27 type IIIA and 11 were type IIIB (p = 0.020). The mean preoperative Harris Hip Score was 45.4 (SD 6.4), becoming 80.7 (SD 12.7) at the final follow-up. In all, 12 hips showed radiological migration of the acetabular component, and three required further revision surgery. The nine-year cumulative failure incidence (nine patients at risk) of the acetabular component for further revision surgery was 9.6% (95% confidence interval (CI) 2.9 to 21.0) for any cause, and 7.5% (95% CI 1.9 to 18.5) for aseptic loosening. Hips with a greater hip height had a higher risk for radiological migration (odds ratio 1.09, 95% CI 1.02 to 1.17; p = 0.008). Conclusion. Bone stock restoration can be obtained using IBG in revision hip surgery. This technique is also useful in re-revision surgery; however, a better surgical technique including a closer distance to hip rotation centre could decrease the risk of radiological migration of the acetabular component. A longer follow-up is required to assess potential fixation deterioration. Cite this article: Bone Joint J 2021;103-B(3):492–499

The treatment of severe acetabular bone loss is challenging, especially in the setting of an associated chronic pelvic discontinuity. There are several available treatment options for chronic pelvic discontinuity, each of which has its own disadvantages. One of the major difficulties with this entity, regardless of the reconstructive technique chosen, is the inability to obtain reproducible healing of the discontinuity. We evaluated the use of acetabular distraction, a technique which achieves peripheral or lateral distraction and central or medial compression across the discontinuity. We recommend acetabular distraction to allow for implantation of a stable construct, achieve biologic fixation and increase the likelihood of discontinuity healing. In this multi-center trial, 32 patients that underwent acetabular revision for a chronic pelvic discontinuity using acetabular distraction were radiographically evaluated at a minimum of 25 months (range, 25 to 160 months). The study cohort was categorized according to the Paprosky acetabular bone loss classification: seven (22%) type IIC, five (16%) type IIIA, and 20 (62%) type IIIB defects. Fourteen (70%) of the 20 patients with a type IIIB acetabular bone loss pattern required use of augments for acetabular reconstruction. Of the 32 patients, 1 (3%) patient required a revision for aseptic loosening, 2 (6%) patients had evidence of radiographic loosening but were not revised, and 3 (9%) patients had migration of the acetabular component into a more stable position. Radiographically, 22 (69%) of the cohort demonstrated healing of the discontinuity. The Kaplan-Meier construct survivorship was 83.3% when using aseptic acetabular loosening as an end-point. During this study, the authors created a new pelvic discontinuity classification based on the type of reconstruction required. The classification mirrors the Paprosky acetabular bone loss classification. A Type I chronic pelvic discontinuity required jumbo cup reconstruction without augments. A type II discontinuity required the use of an augment for an extracavitary defect. A type III discontinuity required an augment for an intracavitary defect. Type III defects were further subdivided into type IIIA and IIIB discontinuity. Type IIIA discontinuities utilized an augment to reconstruct the anterosuperior and/or posteroinferior column defect for primary stability of the overall construct. Type IIIB discontinuities utilized augments to reconstruct the anterosuperior and/or posteroinferior column defect for primary stability as well as a posterosuperior augment for supplemental fixation. All augments were unitized to the cup with cement. Type IV defects were massive defects that required the use of two orange-slice augments, secured together with screws and placed centrally to restore the defect, and a cup implanted and unitized to the augments with cement. According to this new classification, the discontinuity reconstructions in our study were classified as follows: 12 (38%) type I, 8 (25%) type II, 6 (19%) type IIIA, 6 (19%) type IIIB, and 0 as type IV. Acetabular distraction technique demonstrates favorable radiographic outcomes with reproducible discontinuity healing in a majority of cases. This alternative technique allows for biologic fixation and intra-operative customization of the construct to be implanted based on the bone loss pattern present following component removal

Previous reports on the outcomes of isolated head and liner exchange in revision total hip arthroplasty have found high rates of instability following these surgeries. Most reports have studied constructs using ≤28mm femoral heads. The purpose of this study was to determine if modern techniques with the use of larger head sizes can improve the rate of instability after head and liner exchange.

We identified 138 hips in 132 patients who underwent isolated head and liner exchange for polyethylene wear/osteolysis (57%), acute infection (27%), metallosis (13%), or other (2%). All patients underwent revision with either 32mm (23%), 36mm (62%), or 40mm (15%) diameter heads. Crosslinked polyethylene was used in all revisions. Lipped and/or offset liners were used in 104 (75%) hips. Average follow up was 3.5 (1.0–9.1) years. Statistical analyses were performed with significance set at p<0.05.

Revision-free survivorship for any cause was 94.6% and for aseptic causes was 98.2% at 5 years. 11 (8%) hips experienced a complication with 7 (5%) hips requiring additional revision surgery. Following revision, 4 (3%) hips experienced dislocation, 5 (4%) hips experienced infection, and 1 (1%) hip was revised for trunnionosis. No demographic or surgical factors significantly affected outcomes.

Our study shows that isolated head and liner exchange using large femoral heads and modern liners provides for better stability than previous reports. The most common complication was infection. We did not identify specific patient, surgical or implant factors that reduced the risk of instability or other complication.

Introduction. During revision total hip arthroplasty, successful treatment of acetabular bone loss with an associated chronic pelvic discontinuity is dependent upon the remaining bone stock, stability of the construct, potential for biologic fixation, and healing of the discontinuity. Several techniques have been described for the treatment of this clinical entity; the authors recommend the use of acetabular distraction technique in conjunction with a jumbo cup with or without augments. The authors recently evaluated the minimum two-year follow-up of acetabular distraction technique for the treatment of chronic pelvic discontinuity. In the process, a chronic pelvic discontinuity classification was created based on the type of reconstruction required. The purpose of this study is to introduce the initial observations of this novel classification system. Methods. Patients from two academic institutions undergoing acetabular distraction for chronic pelvic discontinuity were identified between January 2002 and December 2013 with minimum 2-year follow-up. Radiographs at latest follow-up were compared to serial radiographs from the index surgery. Data was collected by chart review in accordance with institutional IRB protocol from both institutions. Results. A cohort of 32 patients had minimum 2-year (range, 2.1–13.3 years) follow-up. Mean patient age was 67 years (range, 44–86) and 87% were female. All patients had a chronic pelvic discontinuity with the following bone loss patterns: 7 (22%) type IIC, 5 (15%) type IIIA and 20 (63%) type IIIB. At time of final follow-up, radiographs demonstrated 22 of 32 patients (69%) had evidence of a healed discontinuity. Chronic Pelvic Discontinuity Classification. The classification mirrors the Paprosky classification and requires a more complex reconstruction with each progressive type. For the 20 patients with a type IIIB acetabular bone loss pattern, the new classification was applied. The distribution of classification types was as follows: type I 6 (30%); type II 5 (25%); type IIIA 4 (20%); type IIIB 5 (25%); and type IV 0. Overall, 70% (14) patients required the use of an augment for acetabular reconstruction. Conclusions. Acetabular distraction has been established as an effective method by which to treat chronic pelvic discontinuity. The new classification helps to determine the complexity of reconstruction required for each discontinuity, especially when assessing the most severe acetabular defects (Paprosky IIIB). The authors advocate acetabular distraction with a jumbo cup and modular porous metal augments as the preferred treatment for acetabular bone loss with associated chronic pelvic discontinuity. According to the new classification, the likelihood of utilizing augment(s) increases with severity of bone loss. Future studies are required to validate this new chronic pelvic discontinuity classification

Aims. The aim of this modified Delphi process was to create a structured Revision Hip Complexity Classification (RHCC) which can be used as a tool to help direct multidisciplinary team (MDT) discussions of complex cases in local or regional revision networks. Methods. The RHCC was developed with the help of a steering group and an invitation through the British Hip Society (BHS) to members to apply, forming an expert panel of 35. We ran a mixed-method modified Delphi process (three rounds of questionnaires and one virtual meeting). Round 1 consisted of identifying the factors that govern the decision-making and complexities, with weighting given to factors considered most important by experts. Participants were asked to identify classification systems where relevant. Rounds 2 and 3 focused on grouping each factor into H1, H2, or H3, creating a hierarchy of complexity. This was followed by a virtual meeting in an attempt to achieve consensus on the factors which had not achieved consensus in preceding rounds. Results. The expert group achieved strong consensus in 32 out of 36 factors following the Delphi process. The RHCC used the existing Paprosky (acetabulum and femur), Unified Classification System, and American Society of Anesthesiologists (ASA) classification systems. Patients with ASA grade III/IV are recognized with a qualifier of an asterisk added to the final classification. The classification has good intraobserver and interobserver reliability with Kappa values of 0.88 to 0.92 and 0.77 to 0.85, respectively. Conclusion. The RHCC has been developed through a modified Delphi technique. RHCC will provide a framework to allow discussion of complex cases as part of a local or regional hip revision MDT. We believe that adoption of the RHCC will provide a comprehensive and reproducible method to describe each patient’s case with regard to surgical complexity, in addition to medical comorbidities that may influence their management. Cite this article: Bone Jt Open 2022;3(5):423–431

Aims. The aims of this study were to determine the success of a reconstruction algorithm used in major acetabular bone loss, and to further define the indications for custom-made implants in major acetabular bone loss. Methods. We reviewed a consecutive series of Paprosky type III acetabular defects treated according to a reconstruction algorithm. IIIA defects were planned to use a superior augment and hemispherical acetabular component. IIIB defects were planned to receive either a hemispherical acetabular component plus augments, a cup-cage reconstruction, or a custom-made implant. We used national digital health records and registry reports to identify any reoperation or re-revision procedure and Oxford Hip Score (OHS) for patient-reported outcomes. Implant survival was determined via Kaplan-Meier analysis. Results. A total of 105 procedures were carried out in 100 patients (five bilateral) with a mean age of 73 years (42 to 94). In the IIIA defects treated, 72.0% (36 of 50) required a porous metal augment; the remaining 14 patients were treated with a hemispherical acetabular component alone. In the IIIB defects, 63.6% (35 of 55) underwent reconstruction as planned with 20 patients who actually required a hemispherical acetabular component alone. At mean follow-up of 7.6 years, survival was 94.3% (95% confidence interval 97.4 to 88.1) for all-cause revision and the overall dislocation rate was 3.8% (4 of 105). There was no difference observed in survival between type IIIA and type IIIB defects and whether a hemispherical implant alone was used for the reconstruction or not. The mean gain in OHS was 16 points. Custom-made implants were only used in six cases, in patients with either a mega-defect in which the anteroposterior diameter > 80 mm, complex pelvic discontinuity, and massive bone loss in a small pelvis. Conclusion. Our findings suggest that a reconstruction algorithm can provide a successful approach to reconstruction in major acetabular bone loss. The use of custom implants has been defined in this series and accounts for < 5% of cases. Cite this article: Bone Joint J 2024;106-B(5 Supple B):47–53

Aims. The aim of this study was to compare the biomechanical models of two frequently used techniques for reconstructing severe acetabular defects with pelvic discontinuity in revision total hip arthroplasty (THA) – the Trabecular Metal Acetabular Revision System (TMARS) and custom triflange acetabular components (CTACs) – using virtual modelling. Methods. Pre- and postoperative CT scans from ten patients who underwent revision with the TMARS for a Paprosky IIIB acetabular defect with pelvic discontinuity were retrospectively collated. Computer models of a CTAC implant were designed from the preoperative CT scans of these patients. Computer models of the TMARS reconstruction were segmented from postoperative CT scans using a semi-automated method. The amount of bone removed, the implant-bone apposition that was achieved, and the restoration of the centre of rotation of the hip were compared between all the actual TMARS and the virtual CTAC implants. Results. The median amount of bone removed for TMARS reconstructions was significantly greater than for CTAC implants (9.07 cm. 3. (interquartile range (IQR) 5.86 to 21.42) vs 1.16 cm. 3. (IQR 0.42 to 3.53) (p = 0.004). There was no significant difference between the median overall implant-bone apposition between TMARS reconstructions and CTAC implants (54.8 cm. 2. (IQR 28.2 to 82.3) vs 56.6 cm. 2. (IQR 40.6 to 69.7) (p = 0.683). However, there was significantly more implant-bone apposition within the residual acetabulum (45.2 cm. 2. (IQR 28.2 to 72.4) vs 25.5 cm. 2. (IQR 12.8 to 44.1) (p = 0.001) and conversely significantly less apposition with the outer cortex of the pelvis for TMARS implants compared with CTAC reconstructions (0 cm. 2. (IQR 0 to 13.1) vs 23.2 cm. 2. (IQR 16.4 to 30.6) (p = 0.009). The mean centre of rotation of the hip of TMARS reconstructions differed by a mean of 11.1 mm (3 to 28) compared with CTAC implants. Conclusion. In using TMARS, more bone is removed, thus achieving more implant-bone apposition within the residual acetabular bone. In CTAC implants, the amount of bone removed is minimal, while the implant-bone apposition is more evenly distributed between the residual acetabulum and the outer cortex of the pelvis. The differences suggest that these implants used to treat pelvic discontinuity might achieve short- and long-term stability through different biomechanical mechanisms. Cite this article: Bone Joint J 2024;106-B(5 Supple B):74–81

Aims. Large bone defects resulting from osteolysis, fractures, osteomyelitis, or metastases pose significant challenges in acetabular reconstruction for total hip arthroplasty. This study aimed to evaluate the survival and radiological outcomes of an acetabular reconstruction technique in patients at high risk of reconstruction failure (i.e. periprosthetic joint infection (PJI), poor bone stock, immunosuppressed patients), referred to as Hip Reconstruction In Situ with Screws and Cement (HiRISC). This involves a polyethylene liner embedded in cement-filled bone defects reinforced with screws and/or plates for enhanced fixation. Methods. A retrospective chart review of 59 consecutive acetabular reconstructions was performed by four surgeons in a single institution from 18 October 2018 to 5 January 2023. Cases were classified based on the Paprosky classification, excluding type 1 cases (n = 26) and including types 2 or 3 for analysis (n = 33). Radiological loosening was evaluated by an orthopaedic surgeon who was not the operating surgeon, by comparing the immediate postoperative radiographs with the ones at latest follow-up. Mean follow-up was 557 days (SD 441; 31 to 1,707). Results. Out of the 33 cases analyzed, six (18.2%) constructs required revision, with four revisions due to uncontrolled infection, one for dislocation, and one for aseptic loosening. Among the 27 non-revised constructs, only one showed wider radiolucencies compared to immediate postoperative radiographs, indicating potential loosening. Patients who underwent revision (n = 6) were significantly younger and had a higher BMI compared to those with non-revised constructs (p = 0.016 and p = 0.026, respectively). Sex, race, ethnicity, American Society of Anesthesiologists grade, infection status (patients with postoperative PJI diagnosis (septic) vs patients without such diagnosis (aseptic)), and mean follow-up did not significantly differ between revised and non-revised groups. Conclusion. The HiRISC technique may serve as a feasible short-term (about one to two years) alternative in patients with large acetabular defects, particularly in cases of PJI. Longer follow-up is necessary to establish the long-term survival of this technique. Cite this article: Bone Joint J 2024;106-B(5 Supple B):82–88

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

The best treatment method of large acetabular bone defects at revision THR remains controversial. Some of the factors that need consideration are the amount of residual pelvic bone removed during revision; the contact area between the residual pelvic bone and the new implant; and the influence of the new acetabular construct on the centre of rotation of the hip. The purpose of this study was to compare these variables in two of the most used surgical techniques used to reconstruct severe acetabular defects: the trabecular metal acetabular revision system (TMARS) and a custom triflanged acetabular component (CTAC). Pre- and post-operative CT-scans were acquired from 11 patients who underwent revision THR with a TMARS construct for a Paprosky IIIB defect, 10 with pelvic discontinuity, at Royal Adelaide Hospital. The CT scans were used to generate computer models to virtually compare the TMARS and CTAC constructs using a semi-automated method. The TMARS construct model was calculated using postoperative CT scans while the CTAC constructs using the preoperative CT scans. The bone contact, centre of rotation, inclination, anteversion and reamed bone differences were calculated for both models. There was a significant difference in the mean amount of bone reamed for the TMARS reconstructions (15,997 mm. 3. ) compared to the CTAC reconstructions (2292 mm. 3. , p>0.01). There was no significant difference between overall implant bone contact (TMARS 5760mm. 2. vs CTAC 5447mm. 2. , p=0.63). However, there was a significant difference for both cancellous (TMARS 4966mm. 2. vs CTAC 2887mm. 2. , p=0.008) and cortical bone contact (TMARS 795mm. 2. vs CTAC 2560mm. 2. , p=0.001). There was no difference in inclination and anteversion achieved. TMARS constructs resulted on average in a centre of rotations 7.4mm more lateral and 4.0mm more posterior. Modelling of two different reconstructions of Paprosky IIIB defects demonstrated potential important differences between all variables investigated

For over a decade, modular titanium fluted tapered (TFT) stems have demonstrated excellent clinical success for femoral revision total hip arthroplasty (THA) surgery. The aim of this study was to report the short-term outcomes of a novel modern monoblock TFT stem used for revision and complex primary THA with a minimum of 2 years follow-up. We identified 126 patients who received a single monoblock TFT stem - 26 patients for complex THA (failed fracture fixation) and 100 patients for revision THA. The reasons for revision THA included 40 for previous prosthetic joint infection (PJI), 42 for aseptic loosening, 9 for trunnionosis, 9 for periprosthetic fractures. The Paprosky grading for femoral bone loss at the time of surgery and the measured subsidence of femoral stems at 3 months follow-up were determined. We evaluated the number and indications for re-operations. The mean time from surgery was 3.9 years (range 2.0 to 6.9 years). A paired t-test analysis showed significant improvement from pre-operative versus post-operative clinical outcome scores (p<0.001) for HHS (38.76 +/- 15.24vs. 83.42 +/- 15.38), WOMAC (45.6 ± 19.0 vs. 69.9 ± 21.3) and SF-12 Physical component (31.7 ± 8.1 vs. 37.8 ± 11.3) and SF-12 Mental component (48.2 ± 12.2 vs. 51.6 ± 12.5). The Paprosky grading for femoral bone loss was Grade 1 (3.9%), Grade 2 (35.7%), Grade 3A (47.6%), Grade 3B (11.1%) and Grade 4 (1.6%) cases. There were 18 re-operations (14.7%) with 13 for PJI (7 treated with implant retention, 6 treated with a two-staged revision), 4 for instability and one for acetabular aseptic loosening. There were no aseptic failures of the stem. This novel modern monoblock TFT stem provided reliable femoral fixation and has increasingly supplanted the use of modular TFT stems for complex primary and revision surgery in our institution

Osteolysis, fractures, and bone destruction caused by osteomyelitis or metastasis can cause large bone defects and present major challenges during acetabular reconstruction in total hip arthroplasty. We sought to evaluate the survivorship and radiographic outcomes of an acetabular reconstruction consisting of a polyethylene liner (semi-constrained) embedded in cement filling bone defect(s) reinforced with screws and/or plates for enhanced fixation (HiRISC). Retrospective chart review of 59 consecutive acetabular reconstructions as described above performed by 4 surgeons in a single institution (10/18/2018-1/5/2023) was performed. After radiographs and operative reports were reviewed, cases were classified following the Paprosky classification for acetabular defects. Paprosky type 1 cases (n=26) were excluded, while types 2/3 (n=33) were included for analysis. Radiographic loosening was evaluated up to latest follow-up. Mean follow-up was: 487 days (range, 20–1,539 days). Out of 33 cases, 2 (6.1%) cases were oncological (metastatic disease) and 22 (66.7%) had deep infection diagnosis (i.e., periprosthetic joint infection [PJI] or septic arthritis). In total, 7 (21.2%) reconstructions were performed on native acetabula (3 septic, 4 aseptic). At a mean follow-up of 1.3 years, 5 (15.2%) constructs were revised: 4 due to uncontrolled infection (spacer exchange) and 1 for instability. On follow-up radiographs, only 1 non-revised construct showed increased radiolucencies, but no obvious loosening. When compared to patients with non-revised constructs, those who underwent revision (n=5) were significantly younger (mean 73.8 vs. 60.6 years, p=0.040) and had higher body mass index (24.1 vs. 31.0 Kg/m. 2. , p=0.045), respectively. Sex, race, ethnicity, American-Society-of-Anesthesiologist classification, infection diagnosis status (septic/aseptic), and mean follow-up (449.3 vs. 695.6 days, respectively, p=0.189) were not significantly different between both groups. HiRISC construct may be a viable short-term alternative to more expensive implants to treat large acetabular defects, particularly in the setting of PJI. Longer follow up is needed to establish long term survivorship

As the number of patients who have undergone total hip arthroplasty rises, the number of patients who require surgery for a failed total hip arthroplasty is also increasing. It is estimated that 183,000 total hip replacements were performed in the United States in the year 2000 and that 31,000 of these (17%) were revision procedures. Reconstruction of the failed femoral component in revision total hip arthroplasty can be challenging from both a technical perspective and in preoperative planning. With multiple reconstructive options available, it is helpful to have a classification system which guides the surgeon in selecting the appropriate method of reconstruction. A classification of femoral deficiency has been developed and an algorithmic approach to femoral reconstruction is presented.

An extensively coated, diaphyseal filling component reliably achieves successful fixation in the majority of revision femurs. The surgical technique is straightforward and we continue to use this type of device in the majority of our revision total hip arthroplasties. However, in the severely damaged femur (Type IIIB and Type IV), other reconstructive options may provide improved results. Based on our results, the following reconstructive algorithm is recommended for femoral reconstruction in revision total hip arthroplasty.

Type I: In a Type I femur, there is minimal loss of cancellous bone with an intact diaphysis. Cemented or cementless fixation can be utilised. If cemented fixation is selected, great care must be taken in removing the neo-cortex often encountered to allow for appropriate cement intrusion into the remaining cancellous bone.

Type II: In a Type II femur, there is extensive loss of the metaphyseal cancellous bone and thus, fixation with cement is unreliable. In this cohort of patients, successful fixation was achieved using a diaphyseal fitting, extensively porous coated implant. However, as the metaphysis is supportive, a cementless implant that achieves primary fixation in the metaphysis can be utilised.

Type IIIA: In a Type IIIA femur, the metaphysis is non-supportive and an extensively coated stem of adequate length is utilised to ensure that more than 4cm of scratch fit is obtained in the diaphysis.

Type IIIB: Based on the poor results obtained with a cylindrical, extensively porous coated implant (with 4 of 8 reconstructions failing), our present preference is a modular, cementless, tapered stem with flutes for obtaining rotational stability.

Type IV: The isthmus is completely non-supportive and the femoral canal is widened. Cementless fixation cannot be reliably used in our experience, as it is difficult to obtain adequate initial implant stability that is required for osseointegration. Reconstruction can be performed with impaction grafting if the cortical tube of the proximal femur is intact. However, this technique can be technically difficult to perform, time consuming and costly given the amount of bone graft that is often required. Although implant subsidence and peri-prosthetic fractures have been associated with this technique, it can provide an excellent solution for the difficult revision femur where cementless fixation cannot be utilised. Alternatively, an allograft-prosthesis composite can be utilised for younger patients in an attempt to reconstitute bone stock and a proximal femoral replacing endoprosthesis used for more elderly patients.

Aims. There is a paucity of long-term studies analyzing risk factors for failure after single-stage revision for periprosthetic joint infection (PJI) following total hip arthroplasty (THA). We report the mid- to long-term septic and non-septic failure rate of single-stage revision for PJI after THA. Methods. We retrospectively reviewed 88 cases which met the Musculoskeletal Infection Society (MSIS) criteria for PJI. Mean follow-up was seven years (1 to 14). Septic failure was diagnosed with a Delphi-based consensus definition. Any reoperation for mechanical causes in the absence of evidence of infection was considered as non-septic failure. A competing risk regression model was used to evaluate factors associated with septic and non-septic failures. A Kaplan-Meier estimate was used to analyze mortality. Results. The cumulative incidence of septic failure was 8% (95% confidence interval (CI) 3.5 to 15) at one year, 13.8% (95% CI 7.6 to 22) at two years, and 19.7% (95% CI 12 to 28.6) at five and ten years of follow-up. A femoral bone defect worse than Paprosky IIIA (hazard ratio (HR) 13.58 (95% CI 4.86 to 37.93); p < 0.001) and obesity (BMI ≥ 30 kg/m. 2. ; HR 3.88 (95% CI 1.49 to 10.09); p = 0.005) were significantly associated with septic failure. Instability and periprosthetic fracture were the most common reasons for mechanical failure (5.7% and 4.5%, respectively). The cumulative incidence of aseptic failure was 2% (95% CI 0.4 to 7) at two years, 9% (95% CI 4 to 17) at five years, and 12% (95% CI 5 to 22) at ten years. A previous revision to treat PJI was significantly associated with non-septic failure (HR 9.93 (95% CI 1.77 to 55.46); p = 0.009). At the five-year timepoint, 93% of the patients were alive (95% CI 84% to 96%), which fell to 86% (95% CI 75% to 92%) at ten-year follow-up. Conclusion. Massive femoral bone loss was associated with greater chances of developing a further septic failure. All septic failures occurred within the first five years following the one-stage exchange. Surgeons should be aware of instability and periprosthetic fracture being potential causes of further aseptic revision surgery. Cite this article: Bone Joint J 2021;103-B(7):1247–1253

Introduction

While THA is associated with positive results and long-term improvement in patient quality of life, outcomes are nonetheless associated with adverse events and post-procedural deficits related to discrepancies in leg length (LLD), offset and cup placement. Post-THA errors in these parameters are associated with gait alteration, low back pain and patient dissatisfaction. Such discrepancies often necessitate revision and increasingly lead to medical malpractice litigation.

Maintaining accuracy in post-surgical leg length, offset and cup placement during THA is difficult and subject to error. The sensitivity of these factors is highlighted in studies that have shown that a change of as little as 5 degrees of flexion or abduction can induce alterations in leg length of up to several millimeters. Similarly, positioning of implants can alter global and femoral offset, affecting abductor strength, range of motion and overall physical function. Compounding the biochemical issues associated with inaccurate leg length are the costs associated with these deficits.

Traditional freehand techniques of managing intra-operative parameters rely on surgeon experience and tissue tensioning to manually place components accurately. These methods, however, are only able to assess leg length and are subject to inaccuracies associated with patient movement or orientation changes during surgery. Mechanical methods of minimizing post-surgical discrepancies have been developed, such as outrigger or caliper devices, although these methods also address leg length only and provide poor feedback regarding offset and center of rotation, therefore providing insufficient data to accurately achieve appropriate post-surgical leg length.

Computer-assisted navigation methods provide more data regarding leg length, offset and center of rotation, but are limited by their cumbersome nature and the large capital costs associated with the systems.

The Intellijoint HIP^® surgical smart tool (Intellijoint Surgical, Inc., Waterloo, ON) is an intra-operative guidance tool that provides surgeons with real time data on leg length, offset and center of rotation, thereby allowing for confident selection of the correct implant in order to ensure appropriate post-surgical biomechanics.

The early clinical results from an initial cohort of patients indicate that Intellijoint HIP^® is safe and effective. No adverse events were reported in the initial cohort, and the smart tool was able to measure surgical parameters to within 1mm when compared to radiographic measurements. With training cases removed, 100% of cases had a post-procedure leg length discrepancy of less than 5mm.

This paper describes the indications, procedural technique and early clinical results of the Intellijoint HIP^® smart tool, which offers a safe, accurate and easy-to-use option for hip surgeons to manage leg length, offset and cup position intra-operatively.

The unacceptable failure rate of cemented femoral revisions led to many different cementless femoral designs employing fixation in the damaged proximal femur with biological coatings limited to this area. The results of these devices were uniformly poor and were abandoned for the most part by the mid-1990's.

Fully porous coated devices employing distal fixation in the diaphysis emerged as the gold standard for revisions with several authors reporting greater than 90% success rate 8–10 years of follow-up. Surgical techniques and ease of insertion improved with the introduction of the extended trochanteric osteotomy as well as curved, long, fully porous coated stems with diameters up to 23mm. The limits of these stems were stretched to include any stem diameter in which even 1–2cm of diaphyseal contact could be achieved. When diaphyseal fixation was not possible (Type IV), the alternatives were either impaction grafting or allograft prosthetic composite (APC).

As the results of fully porous coated stems were very carefully scrutinised, it became apparent that certain types of bone loss did not yield the most satisfactory results both clinically and radiographically.

When less than 4cm of diaphyseal press fit (Type IIIB) was achieved, the mechanical failure rate (MFR) was over 25%. It also became apparent that even when there was 4–6cm diaphyseal contact (Type IIIA), and the stem diameter was 18mm or greater, post-operative pain and function scores were significantly less than those with smaller diameter stems. This was probably due to poorer quality bone.

Many of these Type IIIA and Type IIIB femurs had severe proximal torsional remodeling leading to marked distortion of anteversion. This made judging the amount of anteversion to apply to the stem at the time of insertion very difficult, leading to higher rates of dislocation. These distortions were not present in Type I and Type II femurs.

This chain of events which was a combination of minimal diaphyseal fixation, excessively stiff stems and higher dislocation rates led to the conversion to modular type stems when these conditions existed.

For the past 13 years, low modulus taper stems of the Wagner design have been used for almost all Type IIIA and Type IIIB bone defects. The taper design with fluted splines allows for fixation when there is less than 2cm of diaphysis.

The results in these femurs even with diameters of up to 26mm have led to very low MFRs and significantly less thigh pain. Independent anteversion adjustment is also a huge advantage in these modular stems. Similar success rates, albeit with less follow-up, have been noted in Type IV femurs.

Bone is a dynamic organ with remarkable regenerative properties seen only otherwise in the liver. However, bone healing requires vascularity, stability, growth factors, a matrix for growth, and viable cells to obtain effective osteosynthesis. We rely on these principles not only to heal fractures, but also achieve healing of benign bone defects. Unfortunately we are regularly confronted with situations where the local environment and tissue is insufficient and we must rely on our “biologic tool box.” When the process of bone repair requires additional assistance, we often look to bone grafting to provide an osteoconductive, osteoinductive, and/or osteogenic environment to promote bone healing and repair.

The primary workhorses of bone grafting include autogenous bone, cadaver allograft, and bone graft substitutes. Among the first types of bone graft used and still used in large quantities today include autogenous and cadaver allograft bone. Allografts are useful because it is present in multiple forms that conform to the desired situation. But autogenous bone graft is considered the gold standard because it possesses all the fundamental properties to heal bone. However, it has been associated with high rates of donor site morbidity and typically requires an inpatient hospitalization following the procedure only adding to the associated costs.

The first bone graft substitute use was calcium sulfate in 1892, and over the past 122 years advancements have achieved improved material properties of calcium sulfate and helped usher in additional bioceramics for bone grafting. Today there are predominantly four types of bioceramics available, which include calcium sulfate, calcium phosphate, tricalcium phosphate, and coralline hydroxyapatite. They come in multiple forms ranging from pellets and solid blocks to injectable and moldable putty. In comparison to autogenous bone graft, the primary limitation of bioceramics are the lack of osteogenic and osteoinductive properties. Bioceramics work by creating an osteoconductive scaffold to promote osteosynthesis. The options of bone graft substitutes don't end with these four types of bioceramics. Composite bioceramics take advantage of the differing biomechanical properties of these four basis types of bioceramics to develop improved materials. To overcome the lack of osteoinductive and osteogenic properties growth factors or bone marrow aspirate can be added to the bioceramic. As a result, the list of combinations available in our “biologic tool box” continues to expand. More than 20 BMPs have been identified, but only BMP-2 and BMP-7 have FDA approval.

As we look forward to areas of future research and need within orthobiologics, some will likely come in the near future while others are much further in the future. We will continue to strive for the ideal bone graft substitute, which will have similar osteoinductive properties as autograft. The ultimate bone graft substitute will likely involve stem cells because it will allow an alternative to autogenous bone with the same osteogenic potential.

The extended proximal femoral osteotomy has been used primarily in conjunction with cementless fixation, but has been described for use with cemented stems as well. The extended proximal femoral osteotomy is indicated for the removal of well-fixed cemented and cementless implants, as well as removal of cement in patients with a loose femoral component in a well-fixed cement mantle. Although the osteotomy is not required for many femoral revisions, it is an absolute indication in patients with femoral component loosening and subsequent varus remodeling of the proximal femur.

The osteotomy diminishes the risk of an inadvertent fracture of the often compromised greater trochanter especially upon removal of a failed femoral component from its subsided or migrated position. The osteotomy enhances the exposure of the acetabulum which may be difficult in the revision setting due to multiple surgeries, severe migration of the acetabular component or the heterotopic ossification.

The extended proximal femoral osteotomy can also be used in the primary setting when a proximal femoral deformity interferes with straight reaming of the femoral canal, such as in patients with various dysplasias, previous corrective osteotomies or malunions.

As the number of patients who have undergone total hip arthroplasty rises, the number of patients who require surgery for a failed total hip arthroplasty is also increasing. It is estimated that 183,000 total hip replacements were performed in the United States in the year 2000 and that 31,000 of these (17%) were revision procedures. Reconstruction of the failed femoral component in revision total hip arthroplasty can be challenging from a technical perspective and in pre-operative planning. With multiple reconstructive options available, it is helpful to have a classification system which guides the surgeon in selecting the appropriate method of reconstruction. A classification of femoral deficiency has been developed and an algorithmic approach to femoral reconstruction is presented.

Type I:

Minimal loss of metaphyseal cancellous bone with an intact diaphysis. Often seen when conversion of a cementless femoral component without biological ingrowth surface requires revision. Type II: Extensive loss of metaphyseal cancellous bone with an intact diaphysis. Often encountered after the removal of a cemented femoral component. Type IIIA: The metaphysis is severely damaged and non-supportive with more than 4cm of intact diaphyseal bone for distal fixation. This type of defect is commonly seen after removal of grossly loose femoral components inserted with first generation cementing techniques. Type IIIB: The metaphysis is severely damaged and non-supportive with less than 4cm of diaphyseal bone available for distal fixation. This type of defect is often seen following failure of a cemented femoral component that was inserted with a cement restrictor and cementless femoral components associated with significant distal osteolysis. Type IV: Extensive meta-diaphyseal damage in conjunction with a widened femoral canal. The isthmus is non-supportive.

An extensively coated, diaphyseal filling component reliable achieves successful fixation in the majority of revision femurs. The surgical technique is straightforward and we continue to use this type of device in the majority of our revision total hip arthroplasties. However, in the severely damaged femur (Type IIIB and Type IV), other reconstructive options may provide improved results.

As the number of patients who have undergone total hip arthroplasty rises, the number of patients who require surgery for a failed total hip arthroplasty is also increasing. Reconstruction of the failed femoral component in revision total hip arthroplasty can be challenging from both a technical perspective and in pre-operative planning. With multiple reconstructive options available, it is helpful to have a classification system which guides the surgeon in selecting the appropriate method of reconstruction.

Type I: Minimal loss of metaphyseal cancellous bone with an intact diaphysis. Often seen when conversion of a cementless femoral component without biological ingrowth surface requires revision. Type II: Extensive loss of metaphyseal cancellous bone with an intact diaphysis. Often encountered after the removal of a cemented femoral component. Type IIIA: The metaphysis is severely damaged and non-supportive with more than 4 cm of intact diaphyseal bone for distal fixation. This type of defect is commonly seen after removal of grossly loose femoral components inserted with first generation cementing techniques. Type IIIB: The metaphysis is severely damaged and non-supportive with less than 4 cm of diaphyseal bone available for distal fixation. This type of defect is often seen following failure of a cemented femoral component that was inserted with a cement restrictor and cementless femoral components associated with significant distal osteolysis. Type IV: Extensive meta-diaphyseal damage in conjunction with a widened femoral canal. The isthmus is non-supportive.

Based on our results, the following reconstructive algorithm is recommended for femoral reconstruction in revision total hip arthroplasty. An extensively coated, diaphyseal filling component reliably achieves successful fixation in the majority of revision femurs and the surgical technique is straightforward. However, in the severely damaged femur (Type IIIB and Type IV), other reconstructive options may provide improved results. Type I: Cemented or cementless fixation can be utilised. If cemented fixation is selected, great care must be taken in removing the neo-cortex often encountered to allow for appropriate cement intrusion into the remaining cancellous bone. Type II: In this cohort of patients, successful fixation was achieved using a diaphyseal fitting, extensively porous coated implant. However, as the metaphysis is supportive, a cementless implant that achieves primary fixation in the metaphysis can be utilised. Type IIIA: An extensively coated stem of adequate length is utilised to ensure that more than 4 cm of scratch fit is obtained in the diaphysis. Type IIIB: Our present preference is a modular, cementless, tapered stem with flutes for obtaining rotational stability. Type IV: Cementless fixation cannot be reliably used in our experience, as it is difficult to obtain adequate initial implant stability that is required for osseointegration. Reconstruction can be performed with impaction grafting if the cortical tube of the proximal femur is intact. However, this technique can be technically difficult to perform, time consuming and costly given the amount of bone graft that is often required. Although implant subsidence and peri-prosthetic fractures (both intra-operatively and post-operatively) have been associated with this technique, it can provide an excellent solution for the difficult revision femur where cementless fixation cannot be utilised. Alternatively, an allograft-prosthesis composite can be utilised for younger patients in an attempt to reconstitute bone stock and a proximal femoral replacing endoprosthesis used for more elderly patients.

Introduction. Biological repair of acetabular bone defects after impaction bone grafting (IBG) in total hip arthroplasty could facilitate future re-revisions in case of failure of the reconstruction again using the same technique. Few studies have analysed the outcome of these acetabular re-revisions. Patients and Methods. We analysed 34 consecutive acetabular re-revisions that repeated IBG and a cemented cup in a cohort of 330 acetabular IBG revisions. Fresh-frozen femoral head allografts were morselized manually. All data were prospectively collected. Kaplan-Meier survivorship analysis was performed. The mean follow-up after re-revision was 7.2 years (2–17). Intraoperative bone defect had lessened after the first failed revision. At the first revision there were 14 hips with Paprosky 3A and 20 with Paprosky type 3B. At the re-revision there were 5 hips with Paproky 2B, 21 with Paprosky type 3A and 8 with type 3B. Lateral mesh was used in 19 hips. Results. The mean Harris Hip Score improved from 45.4 (6.7) to 77.1 (15.6) at final follow-up. The radiological analysis showed cup migration in 11 hips. The mean appearance time was 25 months (3–72). Of these, migration in three cups was progressive and painful requiring re-revision. Cup tilt was found in all migrated hips. There were one dislocation requiring a cemented dual mobility cup associated with IBG and one infection resolved with resection-arthroplasty. Survival with further cup revision for aseptic loosening was 80.7% (95% Confidence Interval 57.4–100) at 11 years. In all surviving re-revisions trabecular incorporation was observed without radiolucent lines. Conclusion. Biological repair can be obtained by restoring the bone stock, even after successive acetabular reconstructions using IBG and a cemented cup

The management of femoral bone loss is challenging during revision hip arthroplasty. In patients with Paprosky grade IIIB and IV defects, obtaining fixation and rotational stability using traditional surgical constructs is difficult. The use of a custom-made internal proximal femoral replacement prostheses has been proposed as a solution in patients, with severe femoral bone stock loss. However, there is a paucity in the literature on their use and long-term outcomes. We report on the clinical and radiological results of our cohort. We retrospectively reviewed all patients who underwent internal proximal femoral replacement for revision hip arthroplasty between April 1996 and April 2019. All patients had at least 2 years of follow-up time. 160 patients underwent limb salvage at our institution using internal proximal femoral replacement. The mean follow-up was 79.7 months (S.D 41.3). Indications for revision included periprosthetic fractures, aseptic loosening, and deep infection. The mean Oxford hip score increased from 13.8 (0–22) to 31.5 (18–43) (paired t-test, p < 0.001). Kaplan-Meier prosthesis survival analysis with revision as the endpoint was 87% at 5 years. None required revision of the femoral stem. There were four dislocations (5%) and there was failure to eradicate the deep infection in four. This technique allows instant distal fixation, allowing for early mobilisation. Long-term clinical and radiological outcomes are encouraging and the complication rates are acceptable for this patient group

As the number of patients who have undergone total hip arthroplasty rises, the number of patients who require surgery for a failed total hip arthroplasty is also increasing. Reconstruction of the failed femoral component in revision total hip arthroplasty can be challenging from both a technical perspective and in preoperative planning. With multiple reconstructive options available, it is helpful to have a classification system which guides the surgeon in selecting the appropriate method of reconstruction. We have developed a classification of femoral deficiency and an algorithmic approach to femoral reconstruction is presented.

Type I: Minimal loss of metaphyseal cancellous bone with an intact diaphysis. Often seen when conversion of a cementless femoral component without biological ingrowth surface requires revision.

Type II: Extensive loss of metaphyseal cancellous bone with an intact diaphysis. Often encountered after the removal of a cemented femoral component.

Type IIIA: The metaphysis is severely damaged and non-supportive with more than four centimeters of intact diaphyseal bone for distal fixation. This type of defect is commonly seen after removal of grossly loose femoral components inserted with first generation cementing techniques.

Type IIIB: The metaphysis is severely damaged and non-supportive with less than four centimeters of diaphyseal bone available for distal fixation. This type of defect is often seen following failure of a cemented femoral component that was inserted with a cement restrictor and cementless femoral components associated with significant distal osteolysis.

Type IV: Extensive meta-diaphyseal damage in conjunction with a widened femoral canal. The isthmus is non-supportive.

Patella fracture after total knee arthroplasty has a variety of etiologies and has been reported to occur with an incidence ranging from 3% to 21%. Heavy patients with full flexion are at greatest risk for sustaining patella fracture. Overstuffing the patellofemoral joint with an oversized femoral component, an anteriorised femoral component or a femoral component placed in excessive extension can also overload the underlying patella. A similar phenomenon may be seen with underrsection of the patella or use of a thick button. Excessive patellar resection can predispose to patellar fracture as well. It has been demonstrated that a residual patella thickness of less than 15 mm can substantially increase anterior patellar strain. Asymmetric patellar resection can also critically alter the mechanical strength of the patella making it vulnerable to failure.

Elevation of the tibiofemoral joint line, from excessive femoral resection and hastened by posterior cruciate ligament release, will result in a relative patella baja. This can cause early patellofemoral articulation, which may result in patellar impingement on the tibial insert in late flexion and ultimately predispose the patella to fracture.

Surgical approach and soft tissue dissection should be as atraumatic to the patellar blood supply as possible to preserve the superolateral geniculate artery when performing a lateral retinacular release.

The classification used by Goldberg, et al is helpful for planning appropriate intervention:

Type I fractures: Avulsion type fractures generally involving the periphery of the patella without involving the implant.

Type II fractures: Disrupt the cement-prosthesis interfaces of the quadriceps mechanism.

Type IIIA fractures: Involve the pole of the patella with disruption of the patella ligament.

Type IV fractures: Fracture dislocations of the patella. Non-operative treatment is preferred when fractures are non-displaced.

INTRODUCTION: As the number of patients who have undergone total hip arthroplasty rises, the number of patients who require surgery for a failed total hip arthroplasty is also increasing. It is estimated that 183,000 total hip replacements were performed in the United States in the year 2000 and that 31,000 of these (17%) were revision procedures. Reconstruction of the failed femoral component in revision total hip arthroplasty can be challenging from both a technical perspective and in pre-operative planning. With multiple reconstructive options available, it is helpful to have a classification system which guides the surgeon in selecting the appropriate method of reconstruction.

DISCUSSION: An extensively coated, diaphyseal filling component reliably achieves successful fixation in the majority of revision femurs. The surgical technique is straightforward and we continue to use this type of device in the majority of our revision total hip arthroplasties. However, in the severely damaged femur (Type IIIB and Type IV), other reconstructive options may provide improved results. Based on our results, the following reconstructive algorithm is recommended for femoral reconstruction in revision total hip arthroplasty: TYPE I: In a Type I femur, there is minimal loss of cancellous bone with an intact diaphysis. Cemented or cementless fixation can be utilised. If cemented fixation is selected, great care must be taken in removing the neo-cortex often encountered to allow for appropriate cement intrusion into the remaining cancellous bone. TYPE II: In a Type II femur, there is extensive loss of the metaphyseal cancellous bone and thus fixation with cement is unreliable. In this cohort of patients, successful fixation was achieved using a diaphyseal fitting, extensively porous coated implant in 26 of 29 cases (90%) However, as the metaphysis is supportive, a cementless implant that achieves primary fixation in the metaphysis can be utilized. TYPE III A: In a Type IIIA femur, the metaphysis is non-supportive and an extensively coated stem of adequate length is utilised to ensure that more than 4 cm of scratch fit is obtained in the diaphysis. TYPE III B: Based on the poor results obtained with a cylindrical, extensively porous coated implant, our present preference is a modular, cementless, tapered stem with flutes for obtaining rotational stability. Excellent results have been reported with this type of implant and by virtue of its tapered design, excellent initial axial stability can be obtained even in femurs with a very short isthmus. Subsidence has been reported as a potential problem with this type of implant and they can be difficult to insert. However, with the addition of modularity to many systems that employ this concept of fixation, improved stability can be obtained by impacting the femoral component as far distally as needed while then building up the proximal segment to restore appropriate leg length. TYPE IV: In a Type IV femur, the isthmus is completely non-supportive and the femoral canal is widened. Cementless fixation cannot be reliably used in our experience, as it is difficult to obtain adequate initial implant stability that is required for osseointegration. Reconstruction can be performed with impaction grafting if the cortical tube of the proximal femur is intact. However, this technique can be technically difficult to perform, time consuming and costly given the amount of bone graft that is often required. Although implant subsidence and peri-prosthetic fractures have been associated with this technique, it can provide an excellent solution for the difficult revision femur where cementless fixation cannot be utilised. Alternatively, an allograft-prosthesis composite can be utilised for younger patients in an attempt to reconstitute bone stock and a proximal femoral replacing endoprosthesis used for more elderly patients.

The extended proximal femoral osteotomy has been used primarily in conjunction with cementless fixation, but has been described for use with cemented stems as well. The extended proximal femoral osteotomy is indicated for the removal of well-fixed cemented and cementless implants, as well as removal of cement in patients with a loose femoral component in a well-fixed cement mantle. Although the osteotomy is not required for many femoral revisions, it is an absolute indication in patients with femoral component loosening and subsequent varus remodeling of the proximal femur.

The osteotomy diminishes the risk of an inadvertent fracture of the often compromised greater trochanter especially upon removal of a failed femoral component from its subsided or migrated position. The osteotomy enhances the exposure of the acetabulum which may be difficult in the revision setting due to multiple surgeries, severe migration of the acetabular component or heterotopic ossification.

The extended proximal femoral osteotomy can also be used in the primary setting when a proximal femoral deformity interferes with straight reaming of the femoral canal, such as in patients with various dysplasias, previous corrective osteotomies or malunions.

Cup-cage constructs are one of several methods commonly used to treat severe acetabular bone loss during contemporary revision total hip arthroplasty. The purpose of this study was to provide a long-term results of the technique with emphasis on implant survivorship, radiographic results, and clinical outcomes for both full and half cup-cage reconstructions. We identified 57 patients treated with a cup-cage reconstruction for major acetabular bone loss between 2002–2012. All patients had Paprosky Type 2B through 3B bone loss, with 60% having an associated pelvic discontinuity. Thirty-one patients received a full cup-cage construct, and 26 a half cup-cage. Mean age at reconstruction was 66 years, 75% were female, and the mean BMI was 27 kg/m. 2. Mean follow-up was 10 years. The 10-year cumulative incidences of any revision were 14% and 12% for the full and half cup-cage construct groups, respectively. Of the 9 revisions, 3 were for dislocation, 2 for aseptic loosening and construct failure (both were pelvic discontinuities), 1 for adverse local tissue reaction, and 1 for infection with persistent pelvic discontinuity. The 10-year cumulative incidences of revision for aseptic loosening were 4.5% and 5% for the full and half cup-cage constructs, respectively. Of the unrevised cases, incomplete and non-progressive zone 3 radiolucent lines were observed in 10% of patients in each group. Three patients experienced partial motor and sensory sciatic nerve palsies (2 in the full and 1 in the half cup-cage group). Both the full and half cup-cage cohorts demonstrated significantly improved Harris hip scores. Full and half cup-cage reconstructions for major acetabular defects were successful at 10 years in regards to acetabular fixation without appreciable differences between the two techniques. However, zone 3 radiolucent lines were not uncommon in association with discontinuities, and dislocation continues to be a problem

Chronic pelvic discontinuity (CPD) during revision hip arthroplasty is a challenging entity to address. The aim of this study was to evaluate the clinical and radiologic outcomes, and complications of the “acetabular distraction technique” for the management of CPD during revision hip arthroplasty. Patients with CPD, who underwent acetabular revision between 2014 and 2022 at two tertiary care centres, using an identical distraction technique, were evaluated. Demographic parameters, pre-operative acetabular bone loss, duration of follow-up, clinical and radiologic outcomes, and survivorship were evaluated. In all, 46 patients with a mean follow-up of 34.4 (SD=19.6, range: 24–120) months were available for evaluation. There were 25 (54.3%) male, and 21 (45.7%) female patients, with a mean age of 58.1 (SD=10.5, range: 40–81) years at the time of revision surgery. Based on the Paprosky classification of acetabular bone loss, 19 (41.3%), 12 (26.1%), and 15 (32.6%) patients had type 3b, 3a, and 2c defects. All patients were managed using the Trabecular Metal™ Acetabular Revision System; 16 patients required additional Trabecular Metal™ augments. The mean HHS improved from 50.1 (SD=7.6, range: 34.3 – 59.8) pre-operatively, to 86.6 (SD=4.2, range: 74.8 -91.8) at the last follow-up. Two patients (4.3 %) developed partial sciatic nerve palsy, two (4.3%) had posterior dislocation, and one (2.2%) required re-revision for aseptic loosening. Radiologically, 36 (78.3%) patients showed healing of the pelvic discontinuity. The Kaplan-Meier construct survivorship was 97.78% when using re-revision for aseptic acetabular loosening as an endpoint. The acetabular distraction technique has good clinical and radiologic outcomes in the management of CPD during revision hip arthroplasty

Aim. Aim of this monocentric, prospective study was to evaluate the safety, efficacy, clinical and radiographical results at 24-month follow-up (N = 6 patients) undergoing hip revision surgery with severe acetabular bone defects (Paprosky 2C-3A-3B) using a combination of a novel phase-pure betatricalciumphosphate - collagen 3D matrix with allograft bone chips. Method. Prospective follow-up of 6 consecutive patients, who underwent revision surgery of the acetabular component in presence of massive bone defects between April 2018 and July 2019. Indications for revision included mechanical loosening in 4 cases and history of hip infection in 2 cases. Acetabular deficiencies were evaluated radiographically and CT and classified according to the Paprosky classification. Initial diagnosis of the patients included osteoarthritis (N = 4), a traumatic fracture and a congenital hip dislocation. 5 patients underwent first revision surgery, 1 patient underwent a second revision surgery. Results. All patients were followed-up radiographically with a mean of 25,8 months. No complications were observed direct postoperatively. HHS improved significantly from 23.9 preoperatively to 81.5 at the last follow-up. 5 patients achieved a defined good result, and one patient achieved a fair result. No periprosthetic joint infection, no dislocations, no deep vein thrombosis, no vessel damage, and no complaint about limbs length discrepancy could be observed. Postoperative dysmetria was found to be + 0.2cm (0cm/+1.0cm) compared to the preoperative dysmetria of − 2.4 cm (+0.3cm/−5.7cm). Conclusions. Although used in severe acetabular bone defects, the novel phase-pure betatricalciumphosphate - collagen 3D matrixshowed complete resorption and replacement by newly formed bone, leading to a full implant integration at 24 months follow-up and thus represents a promising method with excellent bone regeneration capacities for complex cases, where synthetic bone grafting material is used in addition to autografts

Stem loosening can be associated with a wide spectrum of bone loss and deformity that represent key factors for choosing the most appropriate revision implant. The aim of this study was to evaluate the clinical outcomes and the survivorship of a consecutive series of THA revisions using a taper rectangular cementless stem for primary implants (Alloclassic® Zweymuller®, Zimmer Warsaw US) at medium-term follow-up. We retrospectively evaluated 113 patients (115 revisions) who underwent femoral revision with Zweymuller stem with a preoperative Paprosky I (86) or II (29) defects from January 2011 to December 2020. The mean follow up was 6 years (2–10). The median age at time of surgery was 71(41–93) with 60 males and 53 females. Osteolysis/radiolucency were observed in the following Gruen zones: I (91), II (3), III (2), VII (15), V (3), VI (1). Clinical assessment was performed by means of Harris Hip Score (HHS) and Visual Analogic Scale (VAS), whereas for the radiological analysis we used conventional x-rays of the hips. The statistical analysis was performed using Graphpad Prism v5.0 and data distribution was assessed by Shapiro-Wilk test, and Wilcoxon matched paired test was used to test the differences between preoperative and postoperative score. 9 patients were lost to fu (deceased or not available), 104 (106 hips) were evaluated. The mean HHS and VAS significantly improved at final follow-up, going from 33,84 and 5,78 preoperatively to 66,42 and 2,05 postoperatively, respectively. 28 patients (25%) showed unprogressive radiolucent lines in Gruen zones 1 and 7 with no other radiological nor clinical signs of loosening. One patient suffered from recurrence of the infection. The survivorship with stem revision as endpoint was 100%. Alloclassic Zweymüller primary stem showed good medium-term results and survival rate in revision THA for aseptic loosening and second stages of two stage revisions

First-time revision acetabular components have a 36% re-revision rate at 10 years in Australia, with subsequent revisions known to have even worse results. Acetabular component migration >1mm at two years following revision THA is a surrogate for long term loosening. This study aimed to measure the migration of porous tantalum components used at revision surgery and investigate the effect of achieving press-fit and/or three-point fixation within acetabular bone. Between May 2011 and March 2018, 55 patients (56 hips; 30 female, 25 male) underwent acetabular revision THR with a porous tantalum component, with a post-operative CT scan to assess implant to host bone contact achieved and Radiostereometric Analysis (RSA) examinations on day 2, 3 months, 1 and 2 years. A porous tantalum component was used because the defects treated (Paprosky IIa:IIb:IIc:IIIa:IIIb; 2:6:8:22:18; 13 with pelvic discontinuity) were either deemed too large or in a position preventing screw fixation of an implant with low coefficient of friction. Press-fit and three-point fixation of the implant was assessed intra-operatively and on postoperative imaging. Three-point acetabular fixation was achieved in 51 hips (92%), 34 (62%) of which were press-fit. The mean implant to host bone contact achieved was 36% (range 9-71%). The majority (52/56, 93%) of components demonstrated acceptable early stability. Four components migrated >1mm proximally at two years (1.1, 3.2, 3.6 and 16.4mm). Three of these were in hips with Paprosky IIIB defects, including 2 with pelvic discontinuity. Neither press-fit nor three-point fixation was achieved for these three components and the cup to host bone contact achieved was low (30, 32 and 59%). The majority of porous tantalum components had acceptable stability at two years following revision surgery despite treating large acetabular defects and poor bone quality. Components without press-fit or three-point fixation were associated with unacceptable amounts of early migration

Subsidence remains a concern when utilizing modern tapered fluted titanium (TFT) femoral stems and may lead to leg length discrepancy, impingement, instability and failure to obtain stem osseointegration. This study aims to compare stem subsidence across three modern TFT stems. Our secondary aim was to investigate the influence of bicortical contact or ‘scratch fit’ on subsidence, as well as the role of intraoperative imaging in maximizing this bicortical contact and preventing stem subsidence. A retrospective review of 271 hip arthroplasties utilizing modern TFT stems in a single institution was performed. Three stem designs were included in the analysis: one monoblock TFT stem (n=91) and two modular TFT stems (Modular A [n=90]; Modular B [n=90]). Patient demographics, Paprosky femoral bone loss classification, bi-cortical contact, utilization of intra-operative imaging and stem subsidence (comparison of initial post-operative radiograph to the latest follow up radiograph - minimum three months) were recorded. There was no statistically significant difference in the amount of subsidence between the three stems (Monoblock: 2.33mm, Modular A: 3.43mm, Modular B: 3.02mm; p=0.191). There was no statistical difference in subsidence >5mm between stems (Monoblock: 9.9%, Modular A: 22.2%, Modular B: 16.7%). Subgroup analysis based on femoral bone loss grading showed no difference in subsidence between stems. Increased bicortical contact was strongly associated with reduced subsidence (p=0.004). Intra-operative imaging was used in 46.5% (126/271) of cases; this was not correlated with bicortical contact (p=0.673) or subsidence (p=0.521). Across all groups, only two stems were revised for subsidence (0.7%). All three modern TFT stems were highly successful and associated with low rates of subsidence, regardless of modular or monoblock design. Surgeons should select the stem that they feel is most clinically appropriate