Search

Rationale: Allograft-prosthetic composites (APCs) and proximal femoral replacement have been applied for reconstruction of severe segmental femoral bone loss in revision total hip arthroplasty. The outcomes are encouraging but the complication rate is relatively high. Considering the high complication rates and mixed results of APCs and megaprosthesis, we presented a case using personalized 3D printed Titanium sleeve-prosthetic composite for reconstruction of segmental bone defect. Patient concerns: A 73-year-old woman presented to the emergency department on account of acute severe pain of the left hip without history of trauma. She had undergone a cemented total hip arthroplasty for osteonecrosis of femoral head at the left side in 2000. In 2013 she underwent a cemented revision total hip arthroplasty as a result of aseptic loosening of hip prosthesis. She denied obvious discomfort prior to this episode since the revision surgery in 2013. Diagnosis: According to the clinical history, imaging and physical examination, we confirmed the diagnosis of severe segmental bone loss of proximal femur and fracture of prosthetic stem. The femoral bone defect was evaluated using the Paprosky classification system and rated as Type 3B, and the acetabular bone defect was rated as Type 2C. Interventions: In this study, we present the first case of severe segmental bone loss of proximal femur in revision total hip arthroplasty that was successfully treated using personalized 3D printed Titanium sleeve-prosthetic composite Outcomes: At the 2-year follow-up, the patient was symptom free with a Harris Hip Score of 91. Radiographs showed excellent osteointegration between the interface of sleeve-prosthetic composite and the host bone, with no signs of implant loosening or subsidence. Lessons: Despite the absence of long term results of 3D printed Titanium sleeve-prosthetic composite reconstruction, the good clinical and radiological outcome at 2 years follow up implied its potential role for reconstruction of segmental femoral bone defect in revision THA.

Background Antibiotic cement spacers are used during 2-stage revision total hip arthroplasty for prosthetic joint infection. Complications including dislocation and periprosthetic fracture have been reported but a large cohort comparing spacer design features is lacking. We aimed to determine if spacer design is associated with perioperative complications. Methods We performed a retrospective review of antibiotic cement spacers implanted between 2004 and 2014. Radiographic assessment included leg length, offset, and bone loss (Paprosky classification). Clinical outcomes included dislocation, periprosthetic fracture, spacer fracture, infection cure, and overall reoperation rate. Univariate analysis, Student’s t-test, chi-squared test, or Kruskal-Wallis test was employed (P Results One hundred eighty-five patients were treated: 42% were female and mean age was 64 years (range 24-93, standard deviation 13.6). Spacer types were (1) molded (53%), (2) antibiotic-coated prosthesis (30%), (3) handmade (12%); and (4) prefabricated (4%). Cemented acetabular liners were used in 3% (6/185). There was no loss to follow-up during the interstage period. Spacer complications occurred in 26% (48/185). Dislocation occurred in 9% (17/185) and was associated with reduced femoral offset of >5 mm (P = .033) and increased bone loss (P = .01). Spacer fracture occurred in 8% (14/185); 12% (12/97) molded versus 8% (2/23) handmade (P = .02). Periprosthetic femur fracture was associated with increased offset >5 mm (P = .01) and extended trochanteric osteotomy (P = .001). Conclusion During 2-stage total hip arthroplasty, antibiotic-loaded cement spacers had an overall complication rate of 26%. Spacer design, acetabular and femoral bone loss, and offset restoration were significantly associated with perioperative complications. We recommend the optimization of antibiotic-loaded cement spacer placement to minimize potential complications by focusing on restoration of leg-length and offset, ensuring adequate femoral fixation and paying attention to selection of an appropriate head/neck ratio.

Proximal femoral replacements (PFRs) have been recently utilized in complex revision arthroplasties where proximal femoral bone is compromised. The purpose of this study is to evaluate the clinical outcomes, complications, and survivorship of PFRs as a salvage treatment for severe bone loss after non-oncologic revision total hip arthroplasty. This is a retrospective review of all patients who underwent femoral revision surgery using a single design PFR between 2004 and 2013 at our institution. Forty patients (41 hips) were included with a mean age of 64 years (29–90). According to Paprosky classification, 15 femurs had type IIIB defect, and 26 had type IV defect. Patients were followed for a mean of five years (2–10). The average length of reconstruction was 150 mm (81–261). A Kaplan–Meier analysis was used to determine the survival of the PFR. A total of nine patients (9 PFRs, 22%) were re-operated upon. Three re-operations were for infection, two for dislocation, two for aseptic loosening, and two for periprosthetic fracture. The survivorship at five years was 95.1% for revision of the femoral stem for aseptic loosening. We did not find length of the segmental reconstruction or the indication for revision, to be a risk factor for implant failure or re-revision. Proximal femoral replacements have shown an acceptable survivorship in non-oncologic revision hip arthroplasties for severe proximal femoral bone loss. The frequent use of constrained liners may decrease the risk of dislocation due to the loss of the abductor mechanism encountered in these complex reconstructions.

Previous studies have demonstrated that revision of total hip arthroplasty consumes considerably more resources than the primary procedure. Worse, patients who need revision procedures are more likely to have radiographic evidence of acetabular and femoral bone loss than those undergone primary total hip arthroplasty. Many techniques have been introduced to manage different conditions of acetabular deficiencies. We describe a rare case of a 67-year-old man with severe acetabular bone loss, which was caused by a long-term loose acetabular component and was successfully managed by cup-on-cup technique. We also discuss the similarities and differences between cup-on-cup and cup-in-cup techniques in the management of protrusio acetabular defects, with a case-based approach.

The use of a modular femoral stem in revision total hip arthroplasty (THA) has been increasing recently. However, complications such as subsidence, dislocation and stem fracture are still noted, especially in hips with high grade femoral deficiency. We retrospectively studied a consecutive 41 hips (40 patients) that underwent revision THA with allograft reconstruction of the proximal femur in conjunction with hybrid fixation (proximally cemented and distally press-fit) of a modular femoral component. At a mean follow-up of 5.2 years (2 to 8 years), no hips sustained dislocation, subsidence or fracture of the stem in the follow-up period. We provided evidence that this technique may be a good alternative in the management of proximal femoral bone loss during revision THA.

Objectives A possible solution for the management of proximal femoral bone loss is a modular femoral endoprosthesis (EPR). Although the outcome of EPRs in tumour surgery has been well described, the outcome of their use in revision hip surgery has received less attention. The aim of this study was to describe the outcome of using EPR for non-neoplastic indications. Methods A retrospective review of 79 patients who underwent 80 EPRs for non-neoplastic indications was performed, including the rates of complication and survival and the mean Oxford Hip Scores (OHS), at a mean of five years post-operatively. The mean age at the time of surgery was 69 years (28 to 93) and the mean number of previous operations on the hip was 2.4 (0 to 17). The most common indications for EPR implantation were periprosthetic joint infection (PJI) (n = 40), periprosthetic fracture (n = 12) and failed osteosynthesis of a proximal femoral fracture or complex trauma (n = 11). Results Salvage was achieved in all patients. A total of 25 patients (25 EPRs, 31.6%) had a complication, the most common being infection (n = 9) and dislocation (n = 3). Further surgery was required for 18 EPRs (22%), nine of which were revision procedures. The five year survival of the EPR was 87% (95%CI: 76% to 98%). The mean OHS was 28 (4 to 48). Inferior survival and outcomes were seen in EPRs which were performed for the treatment of infection. However, the eradication of infection was achieved in 33 of the 40 (82.5%) which were undertaken for this indication. Conclusion We recommend the continued use of proximal femoral EPRs for non-neoplastic indications, including PJI. Cite this article: Bone Joint J 2016;98-B:1463–70.

Complex revision total knee arthroplasty (TKA) often calls for endoprosthetic reconstruction to address bone loss, poor bone quality, and soft tissue insufficiency. Larger amounts of segmental bone loss in the setting of joint replacement may be associated with greater areas of devascularized tissue, which could increase the risk of complications and worsen functional results.Are longer endoprosthetic reconstructions associated with (1) higher risk of deep infection; (2) increased risk of reoperation and decreased implant survivorship; or (3) poorer ambulatory status?This is a single-institution retrospective case series of nononcologic femoral endoprosthetic reconstructions for revision TKA from 1995 to 2013 (n = 32). Cases were categorized as distal (n = 17) or diaphyseal (n = 15) femoral reconstructions based on extension to or above the supracondylar metaphyseal-diaphyseal junction, respectively. Five patients from each group were lost to followup before 2 years (distal mean 4 years [range, 2-8 years]; diaphyseal mean = 6 years [range, 2-16 years]), and one of the 12 distal reconstructions and two of the 10 diaphyseal reconstructions had not been evaluated within the past 5 years. Clinical outcomes and ambulatory status (able to walk or not) were assessed through chart review by authors not involved in any cases. Prior incidence of periprosthetic joint infection was high in both groups (distal = seven of 12 versus diaphyseal = four of 10; p = 0.670).Patients with diaphyseal femoral replacements were more likely to develop postoperative deep infections than patients with distal femoral replacements (distal = three of 12 versus diaphyseal = nine of 10; p = 0.004). Implant survivorship (revision-free) for diaphyseal reconstructions was worse at 2 years (distal = 100%, 95% confidence interval [CI], 100%-100% versus diaphyseal = 40%, 95% CI, 19%-86%; p = 0.001) and 5 years (distal = 90%, 95% CI, 75%-100% versus diaphyseal = 30%, 95% CI, 12%-73%; p = 0.001). Infection-free, revision-free survival (retention AND no infection) was worse for diaphyseal femoral replacing reconstructions than for distal femoral replacements at 2 years (distal = 70%, 95% CI, 48%-100% versus diaphyseal = 20%, 95% CI, 6%-69%; p = 0.037) and 5 years (distal = 70%, 95% CI, 48%-100% versus diaphyseal = 10%, 95% CI, 2%-64%; p = 0.012). There was no difference with the small numbers available in proportion of patients able to walk (distal reconstruction = eight of 11 versus diaphyseal = seven of 10; p = 1.000), although all but one patient in each group required walking aids.Endoprosthetic femoral reconstruction is a viable salvage alternative to amputation for treatment of failed TKA with segmental distal femoral bone loss. In our small series even with substantial loss to followup and likely best-case estimates of success, extension proximal to the supracondylar metaphyseal-diaphyseal junction results in higher infection and revision risk. In infection, limb salvage remains possible with chronic antibiotic suppression, which we now use routinely for all femoral replacement extending into the diaphysis.Level III, therapeutic study.

BackgroundComplex revision total knee arthroplasty (TKA) often calls for endoprosthetic reconstruction to address bone loss, poor bone quality, and soft tissue insufficiency. Larger amounts of segmental bone loss in the setting of joint replacement may be associated with greater areas of devascularized tissue, which could increase the risk of complications and worsen functional results.Questions/purposesAre longer endoprosthetic reconstructions associated with (1) higher risk of deep infection; (2) increased risk of reoperation and decreased implant survivorship; or (3) poorer ambulatory status?MethodsThis is a single-institution retrospective case series of nononcologic femoral endoprosthetic reconstructions for revision TKA from 1995 to 2013 (n = 32). Cases were categorized as distal (n = 17) or diaphyseal (n = 15) femoral reconstructions based on extension to or above the supracondylar metaphyseal-diaphyseal junction, respectively. Five patients from each group were lost to followup before 2 years (distal mean 4 years [range, 2-8 years]; diaphyseal mean = 6 years [range, 2-16 years]), and one of the 12 distal reconstructions and two of the 10 diaphyseal reconstructions had not been evaluated within the past 5 years. Clinical outcomes and ambulatory status (able to walk or not) were assessed through chart review by authors not involved in any cases. Prior incidence of periprosthetic joint infection was high in both groups (distal = seven of 12 versus diaphyseal = four of 10; p = 0.670).ResultsPatients with diaphyseal femoral replacements were more likely to develop postoperative deep infections than patients with distal femoral replacements (distal = three of 12 versus diaphyseal = nine of 10; p = 0.004). Implant survivorship (revision-free) for diaphyseal reconstructions was worse at 2 years (distal = 100%, 95% confidence interval [CI], 100%-100% versus diaphyseal = 40%, 95% CI, 19%-86%; p = 0.001) and 5 years (distal = 90%, 95% CI, 75%-100% versus diaphyseal = 30%, 95% CI, 12%-73%; p = 0.001). Infection-free, revision-free survival (retention AND no infection) was worse for diaphyseal femoral replacing reconstructions than for distal femoral replacements at 2 years (distal = 70%, 95% CI, 48%-100% versus diaphyseal = 20%, 95% CI, 6%-69%; p = 0.037) and 5 years (distal = 70%, 95% CI, 48%-100% versus diaphyseal = 10%, 95% CI, 2%-64%; p = 0.012). There was no difference with the small numbers available in proportion of patients able to walk (distal reconstruction = eight of 11 versus diaphyseal = seven of 10; p = 1.000), although all but one patient in each group required walking aids.ConclusionsEndoprosthetic femoral reconstruction is a viable salvage alternative to amputation for treatment of failed TKA with segmental distal femoral bone loss. In our small series even with substantial loss to followup and likely best-case estimates of success, extension proximal to the supracondylar metaphyseal-diaphyseal junction results in higher infection and revision risk. In infection, limb salvage remains possible with chronic antibiotic suppression, which we now use routinely for all femoral replacement extending into the diaphysis.Level of evidenceLevel III, therapeutic study.

This study assessed failures of allograft prosthesis composites (APC) and revisions with a new APC. Twenty-one patients with failed APC's after revision hip arthroplasty with severe proximal femoral bone loss underwent revision with a new APC. Causes of failure were aseptic loosening (18 patients), infection (3 patients). Of these 21 APC revisions, two patients failed (after 60, 156 months). The 5 and 10 year survival rates were 83.5% (95% CI, 79-100%, number at risk 12 and 6 accordingly). In addition, two patients had non-union at the host-allograft bone junction and were augmented with bone autograft and plate. These results suggest that failed APCs may be revised to a new APC with a predictable outcome.

In total hip arthroplasty fixation of revision stems can be demanding due to femoral bone loss. Strut grafts are often used for bone augmentation and stabilization of the newly inserted prosthesis. The aim of this study was to assess the effect of strut grafts on primary stability under various stem fixation conditions.Two different revision stems (cylindrical and conical shape) were implanted into synthetic femora. Following a semicircular transfemoral osteotomy, three deficient femoral bearings were simulated (bony lid reattached with cable wires; weakened lid reattached with cable wires; strut grafts placed to the weakened lid with cable wires). Relative micro-movements were measured between prostheses and bones due to an axial moment applied to the stems.Relative movements correlated to the stem shape. The cylindrical stem showed higher movements increasing significantly with a weakened bony lid and portrayed a slight decrease of movements with strut graft application. No unequivocal influence of the weakened lid could be detected for the conical implant. Strut graft application did not show an additional stabilizing effect.The primary stability of the cylindrical fixation concept decreases with impaired fixation conditions of the femur. A clear restabilizing effect with strut grafts could not be proven. A decrease of primary stability due to the impaired bone could not be observed for the conical stem shape. Additionally, strut grafts do not enhance fixation for this stem shape. We conclude that surgeons should not rely on a stabilizing effect of strut grafts in revision hip surgery.

In revision total hip arthroplasty (THA), proximal femoral bone loss creates a challenge of achieving adequate stem fixation. The purpose of this study was to examine the outcomes of a monoblock, splined, tapered femoral stem in revision THA.Outcomes of revision THA using a nonmodular, splined, tapered femoral stem from a single surgeon were reviewed. With a minimum of 2-year follow-up, there were 68 cases (67 patients). Paprosky classification was 3A or greater in 85% of the cases. Preoperative and postoperative Harris Hip Scores (HHS), radiographic subsidence and osseointegration, limb length discrepancy, complications, and reoperations were analyzed.The Harris Hip Score improved from 37.4 ± SD 19.4 preoperatively to 64.6 ± SD 21.8 at final follow-up (P.001). There were 16 revision procedures-8 for septic indications and 8 for aseptic indications. Subsidence occurred at a rate of 3.0% and dislocation at 7.4%. Limb length discrepancy of more than 1 cm after revision was noted in 13.6% of patients. Bone ingrowth was observed in all but 4 patients (94.1%). At 4-year follow-up, Kaplan-Meier estimated survival was 72.9% (95% confidence interval [CI] 57.0-83.8) for all causes of revision, 86.6% (95% CI 72.0-93.9) for all aseptic revision, and 95.5% (95% CI 86.8-98.5) for aseptic femoral revision.Although complications were significant, revision for femoral aseptic loosening occurred in only 3 patients. Given the ability of this monoblock splined tapered stem to adequately provide fixation during complex revision THA, it remains a viable option in the setting of substantial femoral bone defects.

There still is no consensus on the treatment of choice in revision knee arthroplasty associated with severe femoral and/or tibial bone loss. A total of 44 patients underwent revision knee arthroplasty procedures using porous tantalum cones (TM cones) to reconstruct tibial and/or femoral bone defects. At latest follow up after 37 months (32-48), 38 patients remained in the study. Tibial and femoral bone loss was categorized according to the AORI-Classification. The average preoperative KSS improved from 34 (range, 6-90) to 63 points (range, 7-90 points). The VAS improved from 7.5 to 4.8. Two patients required a re-revision due to aseptic loosening. There was no correlation between the different types of knee prosthesis implanted. Our study shows favourable clinical and radiological outcomes using TM cones in managing significant bone loss in revision total knee surgery.

The prevalence of, risk factors, and management of proximal femoral remodeling in revision total hip arthroplasty is unknown. Therefore, we reviewed the files of 200 consecutive femoral revision arthroplasties to study this phenomenon. Remodeling was considered present if a properly sized diaphyseal-engaging acrylic template had appropriate distal canal fill but lied within 2mm of the proximal lateral endosteal cortex (definition 1) or completely outside the femoral canal (definition 2) on anteroposterior femoral radiographs. The prevalence of remodeling was 42% by definition 1 and 21% by definition 2. The strongest risk factors were loose femoral components and more severe femoral bone loss. Orthopedic surgeons performing revision arthroplasty should be prepared to encounter remodeling as its presence can complicate femoral component revision.

Porous-coated metaphyseal sleeves are designed to fill bone defects and facilitate osseointegration when bone loss in encountered during revision total knee arthroplasty (TKA). The purpose of this study is to evaluate short-term results of porous-coated metaphyseal sleeves with regards to implant fixation and clinical outcomes. A retrospective review was conducted on 50 patients (79 sleeves—49 tibial and 30 femoral) who had a press-fit metaphyseal sleeve with revision TKA. Tibial and femoral bone loss was classified according to the Anderson Orthopaedic Research Institute (AORI) bone defect classification. Post-operative complications of infection, revision surgery, and dislocation were assessed. Follow-up radiographs were evaluated for signs of loosening using the criteria developed by the Knee Society. The median follow-up was 58.8 months (range 25.8–93.0 months). The bone loss classifications were 1 type 1, 30 type 2a, 2 type 2b, and 17 type 3, and with regards to the femur, 5 were type 1, 8 type 2a, 31 type 2b, and 6 type 3. At final follow-up, 41/45 (91.1%) tibial and 28/29 (96.6%) femoral sleeves showed radiographic evidence of ingrowth. Of these 69 patients, all showed radiographic evidence of bony ingrowth. Three sleeves were revised for infection and two for loosening. The re-operation rate for loosening was 5/74 (6.8%) and for any reason was 14/74 (18.9%). Modular porous-coated press fit metaphyseal sleeves fill defects and provide evidence of radiographic ingrowth. Short-term stable fixation can be achieved with sleeves, which is helpful as more patients undergo revision total knee arthroplasty with greater bone loss. Longer duration studies are needed to ascertain the survival rate of these implants. IV.

There is risk of junction failure when using modular femoral stems for revision total hip arthroplasty (THA), especially with loss of bone stock in the proximal femur. Using a cortical strut allograft may provide additional support of a modular femoral construct in revision THA.We reviewed prospectively gathered clinical and radiographic data for 28 revision THAs performed from 2004 to 2014 using cementless modular femoral components with cortical strut allograft applied to supplement proximal femoral bone loss: 5 (18%) were fluted taper designs and 23 (82%) were porous cylindrical designs All the patients had a Paprosky grade IIIA or greater femoral defect. The mean follow-up was 5.4 ± 3.9 years.The Harris Hip Scores improved from 26 ± 10 points preoperatively to 71 ± 10 points at final follow-up (P.001). The Western Ontario McMaster Universities Osteoarthritis Index scores improved from 45 ± 12 points preoperatively to 76 ± 12 points at final follow-up (P.001). Eighty-nine percent (25 hips) of all revision or conversion THAs were in place at final follow-up. Three (11%) patients underwent reoperations, 2 for infection and 1 for periprosthetic fracture. There was no statistical significant change in femoral component alignment (P = .161) at final follow-up. Mean subsidence was 1.8 ± 1.3 mm at final follow-up. Femoral diameter increased from initial postoperative imaging to final follow-up imaging by a mean of 9.1 ± 5.1 mm (P.001) and cortical width increased by a mean of 4.5 ± 2.2 mm (P.001). Twenty-seven hips (96%) achieved union between the cortical strut allograft and the host femur.The use of a modular femoral stem in a compromised femur with a supplementary cortical strut allgraft is safe and provides satisfactory clinical and radiological outcomes.

Background Compromised bone stock and heavily impaired structural integrity after multiple endoprosthetic revision surgeries can lead to a comparable condition as encountered in musculoskeletal tumor surgery. Total femoral replacement (TFR) can restore femoral integrity and allow patients to resume ambulation. Even though several authors reported their results of TFR, so far many questions are still on debate: Which patients are at risk to experience low functional outcome? Do complications and clinical outcome after TFR depend on the indication for the surgery (e.g. periprosthetic fractures or aseptic loosening) or the age of the patients? The purpose of the present study was to compare complication rates after TFR performed with modular total femur prosthesis MML (Fa. ESKA/Orthodynamics) in patients without malignant disease. Methods We conducted a retrospective chart review and functional investigation of patients treated with a TFR for non-oncologic conditions from 1995 to 2015 and a minimum follow-up of 2 years. Complications were recorded according to the Henderson-Classification; outcome was evaluated with established clinical scores. The indication for TFR was periprosthetic fracture (Group A, n = 11) or aseptic loosening (Group B, n = 7) with massive bone defect of the femur deemed unsuitable for conventional arthroplastic or biologic reconstruction. Results Eighteen patients matched the inclusion criteria and could be investigated clinically after a mean follow-up of 80 months (range: 28–132). Before TFA, all patients had previously undergone multiple operations (range: 1–8). The overall failure rate for any reason was 72% (n = 13/18), leading to a total of 37 surgical revisions with total exchange of TFR in 22% (n = 4/18). Most common failure mechanism was Type I (soft tissue), followed by Type IV (infection) and Type III (mechanical failure). According to Enneking’s functional evaluation method (MSTS-Score), the function ranged from 1 to 15 with a mean of 10 ± 4 out of 30. Conclusion TFR is a salvage procedure to restore mechanical integrity and regain functional ability after extensive femoral bone loss. Outcome of the patients in the present study did mainly depend on the age at reconstruction and not on the indication for TFR.

Fracture around the acetabulum and femur in total hip arthroplasty is a possible complication, sometimes with difficult surgical solution, namely when a sepsis is present. Periprosthetic hip fractures were classified according to a modified Vancouver classification. We treated 112 patients (67 men and 45 women) with periprosthetic hip fractures: 105 femoral fractures (94%) and seven acetabular fractures (6%). Mean follow-up was 10.6 years. For Type A (seven cases - 7%), B1 (10 cases - 10%) or C (13 cases - 12%) fractures around well fixed femoral stems we only fixed the fractures. For Type B2 (17 cases - 16%), B3 (46 cases - 44%) and D (12 cases - 11%, with associated fractures, not contemplated in the Vancouver classification) we used an uncemented long femoral stem, fixation with metallic cables and cancellous bone allografts to fill the femoral bone loss. We observed a deep infection in three patients (2.7%), three early hip dislocations treated by closed reductions, two cases with asymptomatic trochanteric non-union and one femoral refracture. In the three infection cases we performed two-stage revision with cementless hip prosthesis, using an antibiotic-loaded cement hip spacer (three to eight months), a six weeks period of parenteral antibiotics and we performed articular aspiration before revision surgery. Until now, we did not observe any re-infection. It is very important to make an early diagnosis, isolate micro-organisms and ensure their antibiotic susceptibility. The surgery solution depends on the well fixed implants and periprosthetic osteolysis and articular instability.

Background: Worldwide use of cementless fixation for total hip arthroplasty (THA) is on the rise despite some evidence from the world’s registries suggesting inferior survivorship compared with cemented techniques. The patterns of bone loss associated with failed cementless and cemented THAs may prejudice the results of future revision procedures; however, this has not been documented. Questions/purposes: The purpose of this study was to compare (1) the risk for rerevision of first revision THA; (2) the patterns of femoral bone loss at the time of first revision of primary THA; (3) the reasons for first revision of primary THA; and (4) the time to first revision of primary THA between primary cementless and cemented femoral components. Methods: Primary THAs with cemented (n = 1791) and uncemented (n = 805) femoral components that subsequently sustained first revision of the femoral component were identified from the Danish Hip Arthroplasty Registry (DHR). As of 2012, 120,988 primary THAs and 19,282 revisions were registered in the DHR with completeness of 97% and 90% for primary and revision THA, respectively. Median followup for revisions of primary THA with cemented and cementless femoral component was 4 years (range, 0–17 years) and 2 years (range, 0–16 years), respectively. Survival of first revision THA, with second revision of the femur as outcome, was evaluated using hazard ratios (HRs) with 95% confidence interval (CI) adjusting for potential confounding. All patient- and surgery-related data are collected from Danish medical databases. Recording of bone defects in the DHR is based on surgeons’ intraoperative findings. Results: With the numbers studied, we found no differences in the risk of second revision between the overall cohort between cementless and cemented techniques (HR, 1.32; 95% CI, 0.97–1.80; p = 0.076); however, a second revision for any reason was more likely in patients

Management of the femur during revision total hip arthroplasty can be challenging. Strategies for femoral reconstruction are based on understanding the degree of femoral bone loss. Numerous options exist for femoral reconstruction depending on the quantity and quality of the remaining femoral bone stock, including cemented fixation, cementless fixation using proximally porous-coated implants, cylindrical extensively porous-coated implants, modular and nonmodular tapered fluted stems, impaction bone grafting, allograft-prosthetic composites, and proximal femoral replacements (megaprostheses). An understanding of the results of various methods of femoral reconstruction is helpful in guiding the revision surgeon faced with a challenging femoral revision.

Distally fixed modular implants have seen a recent increase in use, to manage proximal femoral bone loss often encountered during revision total hip arthroplasty (THA). Forty-three distally fixed modular stems implanted at our institution between 1999 and 2006 were clinically and radiographically reviewed. These patients had either a minimum 2-year follow-up (average, 2.4 years; range, 2-5.6 years) or failure (ie, explant or rerevision required). Eleven stems subsided, and 4 were rerevised (n = 4), for a rate of 9.3%. All revised stems were radiographically undersized, emphasizing the importance of the technique. Although being a valuable option in revision THA, these stems are not free of complications. The high rate of subsidence encountered in our early experience shows that there is a learning curve. This complication is preventable by avoiding undersizing.

Summary Introduction We report a continuous prospective series of patients operated on for total hip prosthesis femoral component loosening involving a bone defect. Reconstruction was performed using a hydroxyapatite-coated locked modular stem. The study's objective was to assess medium term clinical and X-ray results obtained with this original concept. Materials and methods The patients included received a REEF ® (DePuy) femoral implant for aseptic loosening or loosening associated with a periprosthetic fracture. Implantation was systematically accompanied by an extended trochanteric osteotomy (ETO). Patients were followed up prospectively by clinical and X-ray examination. Their loosening was graded at inclusion according to Vives’ classification as revised by SOFCOT in 1999. Analysis focused on actuarial implant survivorship, dislocation and the bone/implant interface. Results Forty-three hips were included: mean follow-up was 58.2 months (12–92) and mean age at surgery was 72.4 years (37–94). The main indications were severe bone loss rated grade III ( n = 15) or IV ( n = 16) according to the SOFCOT classification. There was one long-term failure, involving implant fracture secondary to nonunion of the femoral shaft. Mean Postel and Merle d’Aubigne (PMA) clinical assessment score increased from six preoperatively to 14.5 at end of follow-up. X-ray analysis found no stem migration by end of follow-up. There was consistent consolidation of the ETO around the stem, except in one case of stem fracture which evolved into tight nonunion. In terms of metaphyseal integration, five patients showed radiolucency without evolution over follow-up, and eight had severe calcar cortical atrophy at end of follow-up. Mean 5-year actuarial survivorship was 97.7 ± 2.3%, with a 2% incidence of dislocation. Discussion The complications rate was low, and results were comparable with those reported in the literature. The study confirmed the interest of the extended trochanteric osteotomy exposure and the effectiveness of the hydroxyapatite-coated interlocked modular stem concept in the treatment of hip prosthesis loosening with femoral bone loss (involving or not the cortex). On analysis, the one case of failure does not proscribe the surgical technique employed. Implant osseointegration was difficult to analyze. The extent of the surgical approach and of its corresponding sequels, combined with the complexity of adjusting the implant, however, restrict this surgical option indications to level III and IV cases of femoral loosening. Level of evidence: level IV; therapeutic study.

Severe distal femoral bone loss and instability in revision TKA is challenging. We retrospectively reviewed 39 rotating-hinged distal femoral replacement devices in 37 patients to examine whether improved results were obtainable, using one design, over previously published results. The average age of the patients was 76 years (standard deviation, 10 years). Indications for distal femoral replacement included 11 revision TKAs, 13 periprosthetic fractures, 11 reimplantations, two complex primary TKAs, one distal femoral nonunion, and one acute distal femur fracture. Minimum followup was 24 months (mean, 46 months; range, 24-109 months). Eight patients died during followup. There were five reoperations: two patients with recurrent infection after two-stage treatment, one patient with a periprosthetic fracture treated by open reduction and internal fixation, one patient with late hematogenous infection, and one patient with bearing exchange to treat hyperextension. No failures from aseptic loosening were seen. Knee Society scores improved from 39 preoperatively to 87, and pain scores improved from 18 preoperatively to 43. Distal femoral prosthetic replacement with a tumor-type implant in severe cases provides excellent pain relief and function with a low short-term reoperation rate and an implant survivorship rate of 87% at 46 months.Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Dislocation is a common complication after revision total hip arthroplasty, particularly if the abductor mechanism is deficient. Use of a large femoral head may reduce the incidence of dislocation. However, it is not clear if the large femoral head is effective in controlling dislocation when the abductor mechanism is deficient. We separated 230 patients who underwent revision total hip arthroplasty into four groups: Group 1 (159 patients) had an intact abductor mechanism and a 28-mm femoral head, Group 2 (20 patients) had an absent abductor mechanism (trochanteric nonunion or complete segmental proximal femoral bone loss) and a 28-mm femoral head, Group 3 (42 patients) had an intact abductor mechanism and a 36-mm femoral head, and Group 4 (nine patients) had an absent abductor mechanism and a 36-mm femoral head. The minimum followup was 6 months (mean, 27 months; range, 6 months to 7 years). A 36-mm head was associated with a lower dislocation rate after revision total hip arthroplasty than a 28-mm head with an intact abductor mechanism; the rate of dislocation was 12.7% for Group 1, 40.0% for Group 2, 0% for Group 3, and 33.3% for Group 4. However, the use of a large-diameter head does not reduce the rate of dislocation if the abductor mechanism is absent.

BACKGROUND: Worldwide use of cementless fixation for total hip arthroplasty (THA) is on the rise despite some evidence from the world's registries suggesting inferior survivorship compared with cemented techniques. The patterns of bone loss associated with failed cementless and cemented THAs may prejudice the results of future revision procedures; however, this has not been documented.QUESTIONS/PURPOSES: The purpose of this study was to compare (1) the risk for rerevision of first revision THA; (2) the patterns of femoral bone loss at the time of first revision of primary THA; (3) the reasons for first revision of primary THA; and (4) the time to first revision of primary THA between primary cementless and cemented femoral components.METHODS: Primary THAs with cemented (n = 1791) and uncemented (n = 805) femoral components that subsequently sustained first revision of the femoral component were identified from the Danish Hip Arthroplasty Registry (DHR). As of 2012, 120,988 primary THAs and 19,282 revisions were registered in the DHR with completeness of 97% and 90% for primary and revision THA, respectively. Median followup for revisions of primary THA with cemented and cementless femoral component was 4 years (range, 0-17 years) and 2 years (range, 0-16 years), respectively. Survival of first revision THA, with second revision of the femur as outcome, was evaluated using hazard ratios (HRs) with 95% confidence interval (CI) adjusting for potential confounding. All patient- and surgery-related data are collected from Danish medical databases. Recording of bone defects in the DHR is based on surgeons' intraoperative findings.RESULTS: With the numbers studied, we found no differences in the risk of second revision between the overall cohort between cementless and cemented techniques (HR, 1.32; 95% CI, 0.97-1.80; p = 0.076); however, a second revision for any reason was more likely in patients < 70 years old in whom the index arthroplasty was performed using a cementless technique (HR, 1.48; 95% CI, 1.01-2.17; p = 0.046). Increasingly severe femoral bone defects of type II (30% [532 of 1791] versus 13% [104 of 805]; p < 0.001) type III (11% [200 of 1791] versus 2% [12 of 805]; p < 0.001) and type IV (1% [26 of 1791] versus 0.4% [three of 805]; p = 0.016) were more frequent at revisions of cemented femoral components compared with cementless femoral components. Indications for first revision differed between primary cemented and uncemented femoral components, because a larger proportion of cemented femoral components was revised as a result of aseptic loosening compared with cementless femoral components (74% [1329 of 1791] versus 25% [197 of 805]; p < 0.001), whereas a larger proportion of cementless femoral components was revised as a result of a fracture compared with cemented femoral components (46% [371 of 805] versus 10% [168 of 1791]; p < 0.001). Failure before 5 years was more likely in cementless femoral components than cemented femoral components (91% [733 of 805] versus 44% [749 of 1791], p < 0.001).CONCLUSIONS: We found no differences in the risk of second revision in the overall cohort between cementless and cemented techniques; however, we observed an increased risk for rerevision THA performed on patients < 70 years whose index THAs were performed using cementless components when looking at all causes for revision, even after adjusting for the most likely confounding factors. Our data suggest that increased use of cementless fixation in primary THA may lead to inferior survivorship of first revision THA.LEVEL OF EVIDENCE: Level III, therapeutic study.

Recent studies have indicated that the rate of successful long-term outcome after primary total hip arthroplasty for patients with osteonecrosis may be improved with the use of later-generation porous-coated prostheses (biologic ingrowth fixation) and cement techniques (cement fixation). Less is known about the long-term outcome after revision arthroplasty in the same patient population. The purpose of this study was to characterize the clinical and radiographic outcomes of revision total hip arthroplasty in patients with osteonecrosis.We evaluated thirty-four osteonecrotic hips in thirty patients who had undergone revision of a femoral component of a prior total hip arthroplasty. There were nineteen men (twenty-two hips) and eleven women (twelve hips) with a mean age of forty-six years. Thirty one of thirty-four hips were implanted without cement. The cementless prostheses were of different stem lengths, but thirty of thirty-one were proximally porous coated. The mean duration of follow-up was 8.2 years. Prerevision radiographs were used to determine the degree of femoral bone loss according to the classification system of Della Valle and Paprosky. The need for revision was analyzed for correlation to known risk factors for osteonecrosis, age and gender of the patient, and degree of prerevision femoral deficiency. A clinical and radiographic evaluation of outcome was performed.This was the first revision for twenty-seven hips, the second for five hips, and the third for two hips. Preoperatively, the defects included four Type I, nine Type II, fifteen Type IIIA, two Type IIIB, one Type IV, and three unknown. The femoral component was rerevised in twelve of the thirty-four hips. One of the failures was the only fully porous-coated stem that was implanted. One of the three cemented implants failed, as compared with eleven of the thirty-one noncemented implants. Survival rates were 90.9% at five years, 54.8% at ten years, 54.8% at fifteen years, and 27.4% at twenty years. With the small sample size, no relationship could be identified with regard to frequency of re-revision and defects, associated risk factors, patient age, or gender.There was a high failure rate of revised, uncemented, proximally coated femoral components in patients with osteonecrosis of the femoral head at the time of the intermediate-term follow-up. The cause of failure could not be correlated with patient age, gender, risk factors for osteonecrosis, or femoral bone stock.Therapeutic Level IV. See Instructions to Authors on jbjs.org for a complete description of levels of evidence.

At a minimum of 10 years after surgery, we prospectively evaluated the clinical and radiographic outcomes of revision total hip arthroplasties using cortical strut allografts and fully porous-coated cementless revision femoral components in patients with massive femoral bone deficiency. There were 21 men and 33 women (54 hips) in the series, with patients' mean age at the time of index revision being 54.6 years (range, 36 to 65 years). All femurs had 2 or 3 fresh-frozen femoral strut allografts. The Harris hip score improved from a mean of 21 points before revision surgery to a mean of 83 points at the latest case review. Two femoral stems (4%) had aseptic loosening and were revised. All allografts were predictably united to the host femur. On the basis of favorable results at a mean follow-up of 10.5 years, we recommend, as a salvage procedure, the use of fully porous-coated cementless femoral stems and strut allografts in revision surgery of the hip for massive femoral bone loss.

We have carried out in 24 patients, a two-stage revision arthroplasty of the hip for infection with massive bone loss. We used a custom-made, antibiotic-loaded cement prosthesis as an interim spacer. Fifteen patients had acetabular deficiencies, eight had segmental femoral bone loss and one had a combined defect. There was no recurrence of infection at a mean follow-up of 4.2 years (2 to 7). A total of 21 patients remained mobile in the interim period. The mean Merle D’Aubigné and Postel hip score improved from 7.3 points before operation to 13.2 between stages and to 15.8 at the final follow-up. The allograft appeared to have incorporated into the host bone in all patients. Complications included two fractures and one dislocation of the cement prosthesis. The use of a temporary spacer maintains the function of the joint between stages even when there is extensive loss of bone. Allograft used in revision surgery after septic conditions restores bone stock without the risk of recurrent infection.

Item does not contain fulltext OBJECTIVE: Biological repair of femoral bone loss using bone impaction grafting. Reconstruction of the centre of rotation of the hip using a cemented stem, the size and offset of which are at the discretion of the surgeon. INDICATIONS: Femoral implant loosening with bone loss. CONTRAINDICATIONS: Infection, neurological disorders, noncompliant patient. SURGICAL TECHNIQUE: Extraction of the loose femoral implant, cortical reconstruction using meshes if required, impaction bone grafting with special instruments, cement fixation of a polished tapered stem. POSTOPERATIVE MANAGEMENT: Individualized period of bed rest and limited weight bearing. RESULTS: Impaction bone grafting and a cemented polished stem were used to perform 33 femoral reconstructions. After a mean follow-up of 15 years, no femoral reconstruction had to be revised. One unrecognized intraoperative fracture healed after nonsurgical treatment, three postoperative femoral fractures healed after plate fixation with the stem left in situ. The average Harris Hip Score improved from 49 prior to surgery to 85 points thereafter. Kaplan-Meier analysis with femoral revision for any reason as the end point showed a survival rate of 100 %.

One common approach to the infected total hip arthroplasty (THA) calls for a staged revision, including removal of all components. However, removal of well-fixed femoral components can result in bone loss and compromised fixation; it is not known whether it is effective to leave a well-fixed femoral component in situ, remove only the acetabular component, débride thoroughly, place a spacer, and delay reimplantation.The purposes of this study were to determine (1) the frequency of infection recurrence; (2) the frequency of death; and (3) the Harris hip scores of patients treated with a "two-stage partial exchange" approach.A retrospective analysis from 2000 through January 2011 revealed 19 patients with infected THA treated with partial two-stage exchange including complete acetabular component removal, aggressive soft tissue débridement, retention of the well-fixed femoral stem, placement of an antibiotic-laden cement femoral head on the trunnion of the retained stem, postoperative course of antibiotics, and delayed reimplantation. Indications for this treatment included those patients whose femoral component was determined to be well fixed and its removal would result in significant femoral bone loss and compromise of future fixation. During the study period, this represented 7% (19 of 262) of the patients whom we treated for a chronically infected THA. Minimum followup was 2 years (mean, 4 years; range, 2-11 years). None of the 19 patients in this series were lost to followup. We defined failure as recurrence of infection in the same hip or the use of long-term suppressive antibiotics.Two patients (11%), both with prior failure of two-staged treatment of infection, failed secondary to recurrence of infection at an average of 3.3 years. There were no patient deaths within 90 days. The mean Harris hip score was 68 (range, 31-100; best score is 100).Insofar as 89% of patients in this series were clinically free of infection at a minimum of 2 years, we believe partial two-stage exchange may represent an acceptable option for patients with infected THA when femoral component removal would result in significant bone loss and compromise of reconstruction. Further study is required on this approach.

The purpose of this prospective multicenter study was to evaluate results of 122 revision THAs using a 2nd generation modular femoral implant in 120 patients. Majority of cases had significant femoral bone loss. HHS improved from a pre-operative mean score of 46 to 88 points, and SF-36 scores improved from 31 to 44 points at 2- to 5-year follow-up. There were 18 cases of intraoperative fractures of which 10 were femur shaft, 7 trochanteric, and 1 acetabular. Dislocation incidence was 9% and overall survivorship at 5 years was 97%. Use of modular femoral implants provides versatility and simplification to restore stability, limb length and offset in patients undergoing femoral component revision, Additional steps need to be undertaken to minimize incidence of fracture and dislocation.

Knee revision using constrained implants is associated with greater stresses on the implant and interface surfaces. The present report describes a case of failure of the screw coupling between the stem and the femoral component. The cause of the failure is surmised with outline of the treatment in this case with extensive femoral bone loss. Revision implant stability was augmented with the use of a cemented femoral stem, screw fixation and the metaphyseal sleeve of an S-ROM modular hip system (DePuy international Ltd).

Background: The optimum treatment method for large femoral bone defects during revision knee replacement has not been established. The purpose of the present study was to determine the initial results associated with the use of porous tantalum metaphyseal cones for the treatment of severe femoral bone loss at the time of revision total knee arthroplasty. Methods: Porous tantalum metaphyseal cones were implanted during twenty-four revision total knee replacements. The study group included thirteen women and eleven men with a mean age of sixty-four years at the time of the procedure. The indications for the revision procedure included aseptic loosening of the femoral component (eleven patients), second-stage reimplantation for the treatment of deep infection (seven patients), severe osteolysis around a well-fixed femoral component (three patients), periprosthetic femoral fracture (two patients), and severe knee instability (one patient). Results: The patients were followed for an average of thirty-three months (range, twenty-four to fifty months). Overall, the average Knee Society clinical score improved from 55 points preoperatively to 81 points at the time of the latest follow-up. Radiographic evaluation was completed for twenty patients after a mean duration of follow-up of thirty-five months. All femoral cones appeared well fixed radiographically, with no evidence of complications related to the cone. Conclusions: At the time of short-term follow-up, the porous tantalum metaphyseal femoral cones effectively provided structural support for the femoral implants of a revision total knee arthroplasty in this series. The potential for long-term biologic fixation may provide durability for reconstructions. Long-term follow-up and comparison with alternative reconstructive techniques will be required to evaluate the true effectiveness of this implant. Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.

We report the use of an allograft prosthetic composite for reconstruction of the skeletal defect in complex revision total hip replacement for severe proximal femoral bone loss. Between 1986 and 1999, 72 patients (20 men, 52 women) with a mean age of 59.9 years (38 to 78) underwent reconstruction using this technique. At a mean follow-up of 12 years (8 to 20) 57 patients were alive, 14 had died and one was lost to follow-up. Further revision was performed in 19 hips at a mean of 44.5 months (11 to 153) post-operatively. Causes of failure were aseptic loosening in four, allograft resorption in three, allograft nonunion in two, allograft fracture in four, fracture of the stem in one, and deep infection in five. The survivorship of the allograft-prosthesis composite at ten years was 69.0% (95% confidence interval 67.7 to 70.3) with 26 patients remaining at risk. Survivorship was statistically significantly affected by the severity of the pre-operative bone loss (Paprosky type IV; p = 0.019), the number of previous hip revisions exceeding two (p = 0.047), and the length of the allograft used (p = 0.005).

Choice of the appropriate surgical exposure is an essential for visualization, extraction of old components and for the achievement of a stable and properly aligned construct at the end of the revision surgery. Controlled exposure reduces time of the procedure, minimizes blood loss and bone and soft-tissue damage. Authors introduced MIS direct anterior approach for primary total hip arthroplasty in 2006 year which resulted in necessary revision surgeries in 6 from 37 patients because of component misalignment and recurrent hip dislocation. In two cases only one prosthesis component had to be exchanged and in following four cases prosthesis cup and stem were revised. In 3 procedure was performed via the same surgical approach. In two cases authors performed proximal and distal enlargement of previous MIS approach. In one case revision surgery was performed with separate anterolateral approach. In all revised patients stable and congruent hip prosthesis construct was achieved. Authors did not observed any vascular or nerve lesion. No significant muscle damage was caused by incision enlargement. Revision hip arthroplasty can be performed with use of existing minimally invasive direct anterior approach. In revision cases with intensive femoral bone loss, after MIS direct anterior approach, separate lateral approach should be introduced. Increased risk of complications can be expected during learning phase of new MIS direct anterior approach.

We have managed 27 patients (16 women and 11 men) with a mean age of 68.4 years (50 to 84), with failed total hip replacement and severe proximal femoral bone loss by revision using a distal fix/proximal wrap prosthesis. The mean follow-up was for 55.3 months (25 to 126). The mean number of previous operations was 2.2 (1 to 4). The mean Oxford hip score decreased from 46.2 (38 to 60) to 28.5 (17 to 42) (paired t-test, p < 0.001) and the mean Harris Hip score increased from 30.4 (3 to 57.7) to 71.7 (44 to 99.7) (paired t-test, p < 0.001). There were two dislocations, and in three patients we failed to eradicate previous infection. None required revision of the femoral stem. This technique allows instant distal fixation while promoting biological integration and restoration of bone stock. In the short term, the functional outcome is encouraging and the complication rates acceptable in this difficult group of patients.

In this study, we compared differences in motion at the bone-prosthesis interface in femora in which a fluted, tapered, or cylindrical distal stem design had been implanted in a revision total hip arthroplasty model. Paired, fresh-frozen, cadaveric femora underwent resection of the proximal femur to simulate the proximal femoral bone loss often present during revision total hip arthroplasty and implantation with either a fluted, tapered stem or a clinically proven cylindrical stem. Specimens were then preloaded and subjected to a synchronous axial and torsional load with continuous monitoring of axial displacement and rotation. For the fluted, tapered stem, mean axial and rotational displacements were 13.33 microm and 9.81 microm, respectively, compared with 18.37 microm and 13.40 microm for the cylindrical stem (both Ps.05). Therefore, the fluted, tapered stem design that was tested demonstrated superior initial biomechanical stability compared with that of the clinically proven cylindrical design tested. However, both stems demonstrated motion below the threshold necessary for bony ingrowth. Knowledge of the initial biomechanical properties of different stem designs may assist the revision joint surgeon in choosing the optimal prosthesis for implantation.

The Exeter technique opened new perspectives for the treatment of femoral bone stock loss in revision hip arthroplasty. Implant migration in the cement sheath is, however, a frequent finding. According to the promoters of the technique, this would favor transformation of the allograft into living bone. For others it is a worrisome problem since it alters the heterogeneous cement sheath, leading to loosening and final surgical revision, with an incidence up to 20%. We propose an analysis of the mid-term results of the modified Exeter technique with the objective of cementing the distal part of the implant directly into the recipient bone in order to achieve satisfactory primary stability. The purpose of this work was to analyze the consequences of this method on the long-term evolution of the allograft.After preparing the femur, a specific gun is filled with allograph dough obtained from frozen femoral heads fragmented with an acetabular reamer. The Mersilene mesh enables the deposit of a tube of graft material at the desired level. The implant is sealed after impaction of the graft to enable direct distal cementing in contact with the recipient bone. Partial weight bearing is allowed as early as the fifth day and increased progressively to complete weight bearing at three months. Forty-five patients (46 hips) were treated between June 1996 and January 2002. Six patients were not retained for analysis due to insufficient follow-up. For three patients, graft outcome could not be properly assessed due to a major complication. In addition, two patients died and one was lost to follow-up. In all 39 patients (40 hips) were analyzed at mean follow-up of 84 months (range 48-110). There were no cases of revision for femoral loosening. Femoral bone loss was mainly moderate to severe type II and III hips (Sofcot classification) but limited in height (no grade IV in the Endo-Klinik classification).Clinical outcome was excellent in 13 hips, good in 16, fair in nine and poor in two (Postel-Merle-d'Aubigné score). Defective distal cementing with implant migration (less than 5 mm) was noted in four cases followed by secondary stabilization. Transformation of the allograft occurred in 36 cases, associated with corticalization of the recipient bone in 14.This technique is reproducible since primary stability was obtained in 90% of hips, without hindering transformation of the allograft. The results, which are sustained over time, are the same as with the princeps technique and no radiographic evidence of stress shielding could be found.

The vast majority of femoral revisions that an orthopaedic surgeon encounters can be treated successfully with an extensively porous coated stem. Long-term results have demonstrated that this type of implant can provide reliable initial fixation with a high propensity for long-term fixation. Depending on the degree of femoral bone loss (Paprosky Type IIIA or Type IIIB bone), a longer cementless stem may be required to obtain initial axial and rotational stability. If severe bone loss is present (Paprosky Type IV bone), large canal diameters are encountered (19 mm), or if torsion remodeling of the proximal femur has occurred, alternative methods of fixation may be required.

Background: The Lord prosthesis has been used rather extensively for total hip arthroplasty. In 1981, we began a prospective study for the purpose of determining the long-term results associated with the use of this prosthesis. In the present report, we describe the results for the living patients after a mean duration of follow-up of 17.5 years (range, fifteen to twenty years). Methods: One hundred and two patients (116 hips) with a mean age of sixty-two years at the time of the index arthroplasty were included in the study. Eighty-nine hips were in women, and twenty-seven were in men. The Lord femoral prosthesis (with a 32-mm head) and the Lord threaded cup were used in all patients. The protocol included radiographic analysis, recording of complications, and a clinical evaluation. The patients were evaluated at one to four years, five to nine years, and fifteen to twenty years. Results: One patient (one hip) refused to participate and forty-two patients (forty-five hips) died with the femoral component in place, leaving fifty-nine patients (seventy hips) available for clinical assessment. One femoral component was revised because of mechanical loosening, and one was revised because of a stem fracture. One stem appeared to be loose radiographically. Kaplan-Meier survivorship analysis with revision of the femoral component because of mechanical loosening, stem fracture, or radiographic loosening as the end point revealed a cumulative survival rate of 98% (95% confidence interval, 95.3% to 100.7%) (with twenty-eight hips at risk) at 17.5 years. Seventeen acetabular components were revised because of mechanical loosening, and sixteen were considered to be radiographically loose. Kaplan-Meier survivorship analysis with revision of the acetabular component because of mechanical or radiographic loosening as the end point revealed a cumulative survival rate of 65% (95% confidence interval, 53% to 72%) (with twenty-two hips at risk) at 17.5 years. Conclusions: We believe that the survival rate of the Lord femoral component after 17.5 years of follow-up was excellent. However, there was a substantial rate of proximal femoral bone loss. The results associated with the threaded cup were rather poor, and many patients had a loose implant but few symptoms. We recommend that patients with these implants be followed closely so that revision can be performed before substantial destruction of the acetabulum has occurred. Level of Evidence: Therapeutic study, Level II-1 (prospective cohort study). See Instructions to Authors for a complete description of levels of evidence.

Considerable femoral bone loss can be encountered in the multiply revised total hip arthroplasty patient. Deficient proximal bone requires either a bulk allograft or a femoral component that allows stable distal fixation. Extensively coated stems have shown excellent results for many revisions but have shown higher rates of failure among patients with femoral remodeling in retroversion, an enlarged endosteal diameter, or an ectatic canal. A modular tapered stem is an alternative in this subset of patients. A modular tapered implant provides axial and rotational stability through the use of distal splines, and the proximal body segments can allow independent adjustment of leg length, offset, and anteversion.

Massive osteolytic bone loss in revision total knee arthroplasty has been an uncommon challenge. From 2001 to 2002, 11 knees in 10 patients underwent revision of failed modular PFC (Johnson and Johnson Orthopaedics, Raynham, Mass) total knee arthroplasties with distal femoral allografts and long-stemmed revision implants for massive osteolytic induced femoral bone loss. The mean follow-up was 42 months (range, 36-48 months). Radiographic graft incorporation was demonstrated in all 11 knees with no cases of loosening. The Knee Society Pain Scores improved by an average of 25.4 points, and the function scores improved by an average of 23.3 points. The outcomes of distal femoral allografts in the reconstruction of massive osteolytic bone loss associated with failed modular PFC (Johnson and Johnson Orthopaedics) total knee arthroplasties are favorable.

Femoral revision total hip arthroplasty is a technically demanding procedure. In addition to these technical issues, preoperative planning can be challenging and with multiple reconstructive options available, the decision-making process can be complex. The ability to preoperatively determine the most appropriate option for reconstruction greatly assists with ensuring that the appropriate implants and instruments are available at the time of surgery. A classification of femoral bone loss is presented that guides the surgeon in selecting an appropriate method of reconstruction.

The exact role of proximal femoral replacement (megaprosthesis) in revision hip surgery is unclear. During the past decade remarkable advances in the field of revision hip reconstruction have been made including the availability of allograft cancellous and cortical bone. With the increased use of cortical strut grafts to augment host bone, the indications for the use of megaprostheses have narrowed. Currently, we reserve the use of megaprostheses for elderly or sedentary patients with massive proximal femoral bone loss that cannot be reconstructed by other reconstructive procedures. This may include failed total hip arthroplasty (THA), nonunion of the proximal femur with multiple failed attempts at osteosynthesis, and hip salvage after a failed resection arthroplasty.