Revision Of Femoral Component Research Articles

Infection After Unicompartmental Knee Arthroplasty: A High Risk of Subsequent Complications.

Unicompartmental knee arthroplasty restores function and improves pain in appropriately selected patients. Scant evidence exists regarding the treatment of periprosthetic joint infection (PJI) after unicompartmental knee arthroplasty (UKA). (1) What was the overall survivorship free from reinfection? (2) What is the survivorship free of all-cause revision? (3) What are the Knee Society scores (KSS) and complications after surgical treatment of UKA PJI? This retrospective study with data drawn from a longitudinally maintained institutional registry identified 15 UKA PJIs between 1992 and 2014. The median age at PJI diagnosis was 58 years (range, 41-82 years), nine of 15 were men, and the median body mass index was 29 kg/m (range, 23-36 kg/m). Ten patients (10 of 15) satisfied major Musculoskeletal Infection Society diagnostic criteria. There were five patients (five of 15) with early postoperative infections, five (five of 15) with acute hematogenous infections, and five (five of 15) with chronic PJIs. Two-stage exchange was performed in four patients with PJIs (four of 15), and débridement, antibiotics, and implant retention (DAIR) was performed in 11 patients (11 of 15) with PJIs. We performed Kaplan-Meier survivorship analysis for reinfection and revision procedures. Thirteen patients had a minimum of 2 years' followup and were included in the clinical analysis. Median followup was 4 years (range, 2-6 years). We calculated KSS. Infection-free survivorship was 71% at 5 years (95% confidence interval [CI], 46%-96%). Treatment success was higher for patients undergoing two-stage exchange (100% at 5 years; 95% CI, 100%-100%) versus DAIR (61% at 5 years; 95% CI, 31%-92%). Four of 11 patients undergoing DAIR had developed a reinfection at final followup. Survivorship free of any revision was 49% at 5 years (95% CI, 19%-79%). One patient from the two-stage exchange cohort underwent femoral component revision for aseptic loosening 5 years after PJI treatment, and two patients from the DAIR group were converted to TKA for disease progression at a mean of 4 years. In patients with a minimum of 2 years' followup, median KSS improved from 73 (range, 50-93) before index UKA to 94 (range, 55-100; p = 0.016). Treatment of UKA PJI with DAIR was associated with a lower infection-free survivorship at 5 years compared with two-stage exchange with conversion to TKA. Among those patients who were infection-free, a number needed reoperations for disease progression (in the DAIR group) or component loosening (in both groups). UKA PJI results in substantial morbidity, and patients with these infections should be followed closely for aseptic causes of failure in addition to infection recurrence. Level IV, therapeutic study.

Early femoral condyle insufficiency fractures after total knee arthroplasty: treatment with delayed surgery and femoral component revision

BackgroundPeriprosthetic fracture following total knee arthroplasty (TKA) is usually associated with a traumatic event and typically treated with fracture fixation techniques. However, we report on a series of patients with early atraumatic condyle fractures that occurred as a result of insufficiency of the unloaded preoperative femoral condyle treated with delayed reconstruction.MethodsWe retrospectively reviewed a series of 7 patients who sustained femoral condyle fractures following TKA and evaluated risk factors for insufficiency.ResultsThere were 6 females and 1 male with an average age of 65.5 (range, 63-75) years and an average body mass index of 29.4 (range, 27-32). Fracture occurred on average 24.9 days from the index surgery and secondary to a low energy mechanism. Five patients had valgus alignment (mean, 15.2°) preoperatively and sustained fracture of the unloaded medial femoral condyle. Two patients had varus alignment (mean, 7.0°) preoperatively and both fractured the unloaded lateral condyle. One patient underwent early intervention requiring distal femoral replacement secondary to femoral bone loss. The remaining 6 patients underwent delayed surgery for an average of 6 weeks to allow for fracture healing followed by femoral component revision. At last follow-up (average, 48.5 months), 1 patient required a tibial component revision; however, no revision of the femoral component was required.ConclusionsEarly femoral condyle insufficiency fractures following TKA may be a risk in females with poor bone quality and preoperative valgus alignment. Delayed surgery and femoral component revision is a treatment strategy that prevented the need for other tertiary reconstruction.

Long-Term Outcomes After Metal-on-Metal Total Hip Arthroplasty With a 28-mm Head: A 17- to 23-Year Follow-Up Study of a Previous Report

BackgroundSecond-generation, metal-on-metal total hip arthroplasty (MoM THA) using a 28-mm head has shown favorable results compared with large head MoM THA. The purpose of this study is to evaluate the long-term outcomes of cementless primary MoM THA with a 28-mm head and the incidence of osteolysis using computed tomography. MethodsA total of 92 patients (53 men and 39 women) who underwent primary cementless MoM THA (114 hips) with a 28-mm head were enrolled in this study. Their mean age was 46.2 years at the time of surgery. The mean follow-up duration was 20 years. The Harris hip score, presence of thigh or groin pain, radiographic results, presence of peri-implant osteolysis, histologic analysis, and Kaplan-Meier survival curves were evaluated. ResultsThe mean preoperative Harris hip score of 50.5 improved to 85.1 at the final follow-up. Eight patients (8 hips) experienced groin pain, but none had thigh pain. Twelve revisions (6.2%) were performed including 10 hips for aseptic loosening with osteolysis and 2 hips for periprosthetic fracture around the stem. At 23 years, 91% of patients were free from revision of the acetabular component due to aseptic loosening and 90.1% were free from revision of both femoral and acetabular components due to any reason. Osteolysis was identified around the cup in 12 cases (10.5%) and around the stem in 7 cases (6.1%). ConclusionMoM THA with a 28-mm head showed a relatively low rate of aseptic implant loosening at a mean follow-up of 20 years.

Cement augmentation in the proximal femur to prevent stem subsidence in revision hip arthroplasty with Paprosky type II/IIIa defects

BackgroundSubsidence remains a common complication after revision hip arthroplasty which may lead to prolonged weight-bearing restrictions, leg-length discrepancies or considerable loss of function. We evaluated the effectiveness of cement augmentation in the proximal femoral metaphysis during a revision of femoral components to prevent post-operative stem subsidence. MethodsForty patients were enrolled. Follow-up averaged 67.7 months (range: 24–149). Twenty-seven patients had a Paprosky type II defect and 13 had a type IIIa defect. All revision hip arthroplasty used a cementless, cylindrical, non-modular cobalt–chromium stem. The defect in the metaphysis was filled with antibiotic-loaded bone cement. Thirteen patients who had undergone stem revision only was allowed to walk immediately without weight-bearing restrictions. Twenty-seven patients who had undergone revision total hip arthroplasty was allowed partial weight-bearing within 6 weeks after surgery in the consideration of acetabular reconstruction. ResultsThree patients (7.5%) had post-surgery stem subsidences of three mm, five mm, and 10 mm, respectively, at three, one, and 14 months. There were no acute surgical site infections. There were three femoral stem failures: two delayed infections and one periprosthetic Vancouver B2 fracture. Both five- and 10-year survivorships of the femoral implant were 90.1%. ConclusionAn adequate length of the scratch-fit segment and diaphyseal ingrowth remain of paramount importance when revising femoral components. To fill metaphyseal bone defects with antibiotic-loaded bone cement may be an alternative method in dealing with proximal femoral bone loss during a femoral revision.

Preliminary experience of the Cannulok revision hip prosthesis in late periprosthetic fracture management.

We report our preliminary experience of a cannulated, distally locked revision femoral component to manage peri-prosthetic fractures in the elderly. The majority of cases in our series were further complicated by osteolysis secondary to aseptic loosening, the original hip arthroplasties having been in situ for several years. Sixteen patients with an average age of 77 underwent treatment of periprosthetic fractures with the Cannulok Hip. The device combines techniques of revision hip surgery with locked intramedullary nailing. We describe our initial evaluation of this modular prosthesis which has enabled us to satisfactorily treat periprosthetic fractures with early mobilisation and discharge from hospital. In all of our surviving patients the fractures have united within four to six months. All cases were in addition treated with proximal femoral impaction allografting leading to improved local bone stock. We believe this implant may provide a satisfactory alternative for the management of periprosthetic fracture in the presence of a loose femoral component. (Hip International 2002; 1: 1-10).

Outpatient Total Knee Arthroplasty Is Associated with Higher Risk of Perioperative Complications.

As concerns regarding health-care expenditure in the U.S. remain at the national forefront, outpatient arthroplasty is an appealing option for carefully selected patient populations. The purpose of this study was to determine the nationwide trends and complication rates associated with outpatient total knee arthroplasty (TKA) in comparison with standard inpatient TKA. We performed a retrospective review of the Humana subset of the PearlDiver Patient Record Database to identify patients who had undergone TKA (Current Procedural Terminology [CPT] code 27447) as either outpatients or inpatients from 2007 to 2015. The incidence of perioperative medical and surgical complications was determined by querying for relevant International Classification of Diseases, Ninth Revision (ICD-9) and CPT codes. Multivariate logistic regression analysis adjusted for age, sex, and Charlson Comorbidity Index (CCI) was used to calculate odds ratios (ORs) of complications among outpatients relative to inpatients treated with TKA. Cohorts of 4,391 patients who underwent outpatient TKA and 128,951 patients who underwent inpatient TKA were identified. The median age was in the 70 to 74-year age group in both cohorts. The incidence of outpatient TKA increased across the study period (R = 0.60, p = 0.015). After adjustment for age, sex, and CCI, outpatient TKAs were found to more likely be followed by tibial and/or femoral component revision due to a noninfectious cause (OR = 1.22, 95% confidence interval [CI] = 1.01 to 1.47; p = 0.039), explantation of the prosthesis (OR = 1.35, CI = 1.07 to 1.72; p = 0.013), irrigation and debridement (OR = 1.50, CI = 1.28 to 1.77; p < 0.001), and stiffness requiring manipulation under anesthesia (OR = 1.28, CI = 1.17 to 1.40; p < 0.001) within 1 year. Outpatient TKA was also more frequently associated with postoperative deep vein thrombosis (OR = 1.42, CI = 1.25 to 1.63; p < 0.001) and acute renal failure (OR = 1.13, CI = 1.01 to 1.25; p = 0.026). With the potential to minimize arthroplasty costs among healthy patients, outpatient TKA is an increasingly popular option. Nationwide data from a private insurance database demonstrated a higher risk of perioperative surgical and medical complications including component failure, surgical site infection, knee stiffness, and deep vein thrombosis. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Experience in the use of Distal Fixation Femoral Component Use in Revision Hip Arthroplasty

Purpose. To evaluate the efficacy of revision hip arthroplasty with use of distal fixation revision femoral component.Patients and methods. From June 2004 through October 2015 one hundred thirteen revision arthroplasties were performed in patients with type 3A, 3B and 4 femoral defects by Paprovsky classification. Solution, Wagner SL and Cerafit revision femoral components for distal fixation were used. In the majority of cases (87) the cause of revision intervention was aseptic instability of the femoral component. In 60 cases revision was performed for cementless femoral components, in 53 - for cement components.Results.Follow up period made up from 1 to 12 years. In 83.2% of cases excellent, good and satisfactory treatment results, i.e. pain syndrome remission, restoration of joint movements and extremity weight bearing ability were achieved.Conclusion.Wagner SL, Solution and Cerafit modular revision stems ensure acceptable clinical treatment results and can be the implants of choice for hip femoral component revision arthroplasty in types 3A, 3B and 4 femoral defects by Paprovsky.

Experience in the use of Distal Fixation Femoral Component Use in Revision Hip Arthroplasty

Purpose . To evaluate the efficacy of revision hip arthroplasty with use of distal fixation revision femoral component. Patients and methods. From June 2004 through October 2015 one hundred thirteen revision arthroplasties were performed in patients with type 3A, 3B and 4 femoral defects by Paprovsky classification. Solution, Wagner SL and Cerafit revision femoral components for distal fixation were used. In the majority of cases (87) the cause of revision intervention was aseptic instability of the femoral component. In 60 cases revision was performed for cementless femoral components, in 53 - for cement components. Results. Follow up period made up from 1 to 12 years. In 83.2% of cases excellent, good and satisfactory treatment results, i.e. pain syndrome remission, restoration of joint movements and extremity weight bearing ability were achieved. Conclusion. Wagner SL, Solution and Cerafit modular revision stems ensure acceptable clinical treatment results and can be the implants of choice for hip femoral component revision arthroplasty in types 3A, 3B and 4 femoral defects by Paprovsky.

Do High-Flexion Total Knee Designs Increase the Risk of Femoral Component Loosening?

BackgroundThe purpose of our prospective, randomized, long-term investigation is to compare the aseptic loosening rate of the femoral component of the total knee prosthesis and clinical and radiographic results of high-flexion posterior cruciate-substituting knee prosthesis or standard posterior cruciate-substituting knee prosthesis in the same patients. MethodsThere were 960 patients (mean age 71.3 years). The mean follow-up period was 13.2 years (range 10-14). The patients were assessed clinically and radiographically with rating systems of the Knee Society. Furthermore, Western Ontario and McMaster Universities Osteoarthritis questionnaire and ranges of knee motion were determined in both groups. ResultsIn the high-flexion knee group, 2 knees (0.2%) had aseptic loosening of both femoral and tibial components. In the standard knee group, 2 knees (0.2%) had aseptic loosening of the femoral component only. The mean postoperative knee scores (97 vs 97 points), Western Ontario and McMaster Universities Osteoarthritis scores (19 vs 19 points), and range of knee motion (128° vs 129°) were not significantly different between the 2 groups. Two knees (0.2%) in the high-flexion knee group underwent a revision of both femoral and tibial components and 2 knees (0.2%) in the standard knee group had a revision of the femoral component only. ConclusionAfter a mean of 13.2 years of follow-up, this study did not show increased incidence of femoral component loosening in the high-flexion knee group. Furthermore, we found no significant differences between the 2 groups with regard to clinical or radiographic parameters or range of knee motion.

Cement-in-cement femoral component revision in the multiply revised total hip arthroplasty: results with a minimum follow-up of five years.

We present the clinical and radiological results at a minimum follow-up of five years for patients who have undergone multiple cement-in-cement revisions of their femoral component at revision total hip arthroplasty (THA). We reviewed the outcome on a consecutive series of 24 patients (10 men, 14 women) (51procedures) who underwent more than one cement-in-cement revision of the same femoral component. The mean age of the patients was 67.5 years (36 to 92) at final follow-up. Function was assessed using the original Harris hip score (HHS), Oxford Hip Score (OHS) and the Merle D'Aubigné Postel score (MDP). The mean length of follow-up was 81.7 months (64 to 240). A total of 41 isolated acetabular revisions were performed in which stem removal facilitated access to the acetabulum, six revisions were conducted for loosening of both components and two were isolated stem revisions (each of these patients had undergone at least two revisions). There was significant improvement in the OHS (p = 0.041), HHS (p = 0.019) and MDP (p=0.042) scores at final follow-up There were no stem revisions for aseptic loosening. Survival of the femoral component was 91.9% (95% confidence intervals (CI) 71.5 to 97.9) at five years and 91.7% (95% CI 70 to 97) at ten years (number at risk 13), with stem revision for all causes as the endpoint. Cement-in-cement revision is a viable technique for performing multiple revisions of the well cemented femoral component during revision total hip arthroplasty at a minimum of five years follow-up. Cite this article: Bone Joint J 2017;99-B:199-203.

Femoral impaction allografting for significant bone loss in revision hip arthroplasty.

Femoral impaction bone allografting in revision hip arthroplasty facilitates physiological reconstruction with restoration of bone stock, allowing implantation of a standard cemented femoral component. The purpose of this study was to report our experience in femoral component revision arthroplasty with impaction morsellised cancellous bone allograft using custom impactors and a cemented triple-taper polished stem. Retrospective analysis of all cases of femoral component revision hip arthroplasty with impaction bone grafting undertaken by a single surgeon from 2005 to 2011. Outcome measures included radiographic analysis of stem subsidence over time, graft remodelling and incorporation, and clinical progress. We reviewed 47 consecutive hips in 44 patients, mean age 62 years (37-88). Femoral impaction with allograft was performed as either single stage (41 cases) or 2-stage (6 cases) procedures. All patients received a cemented C-stem prosthesis. The mean follow-up period was 5.1 (1.3-9.4) years. The median preoperative bone defect score was 3 (interquartile range [IQR] 2-3) using the Endo-Klinik classification. Radiological evidence of graft incorporation was observed in 89% (281 of 315 zones) with additional remodelling observed in 33% (103 of 315 zones). The median stem subsidence at 1-year follow-up was 1.1 mm (standard deviation [SD] 1.24 mm, range 0-6 mm). The median Oxford Hip Score at the most recent follow-up was 36.5. To date no femoral component has undergone further revision. Encouraging results have been obtained with this technique for the treatment of significant bone loss in revision hip arthroplasty, allowing implantation of a standard prosthesis.

Femoral Component Revision of Total Hip Arthroplasty.

Modern primary total hip arthroplasty (THA) is among the most successful operations in medicine. It has been a consistently effective treatment for end-stage osteoarthritis of the hip. With the increasing number of primary THA procedures being performed and the decreasing age of patients undergoing the procedure, there is an inevitable associated increase in revision burden for arthroplasty surgeons. Revision THA is most often indicated for instability, aseptic loosening, osteolysis, infection, periprosthetic fracture, component malposition, and catastrophic implant failure. Understanding the etiology of THA failure is essential for guiding clinical decision making. Femoral component revision presents a complex challenge to the arthroplasty surgeon because of modern implant design as well as bone loss in the proximal femur. Thorough patient evaluation, defect classification, and well-executed surgical reconstruction based on comprehensive preoperative planning may determine the postoperative results. Knowledge of various reconstructive options and the indications for each is necessary to achieve a successful outcome. This article highlights the most common indications for revision after THA and offers recommendations for how to approach revision of the femoral component. Specifically, the authors review preoperative assessment, common classification systems for femoral deficiency, techniques for component extraction, and modalities of femoral component fixation. [Orthopedics. 2016; 39(6):e1129-e1139.].

Medial patellofemoral ligament reconstruction for patellar instability following total knee arthroplasty: A review of 6 cases

IntroductionPatellar instability is a frequent cause of total knee arthroplasty (TKA) failure. In cases of post-arthroplasty patellar instability, the medial structures may be damaged. The objective of this study was to study the effectiveness of medial patellofemoral ligament (MPFL) reconstruction. We hypothesized that MPFL reconstruction will effectively realign the patella, making it a viable treatment option for managing post-arthroplasty patellar instability. Material and methodsIn this retrospective study of six patients treated by four different surgeons, patients were included if they had a recurring or permanent patellar dislocation after undergoing TKA. Patients were excluded if the patellar instability was painful but did not result in dislocation. Each patient underwent MPFL reconstruction using the gracilis; additional procedures could be performed depending on the diagnosis. One patient required TKA revision because of an abnormally rotated femoral implant. The main outcome measure was the non-recurrence of the dislocation. The IKDC and Kujala functional scores, joint range of motion and patellar tilt on X-rays were analyzed preoperatively and at the last follow-up. ResultsAt a mean follow-up of 23 months (6–46), none of the patients experienced a recurrence of the patellar dislocation. Only one patient had no improvements in the functional outcome scores. The patellar tilt was reduced in all patients. ConclusionMPFL reconstruction—in isolation or with femoral component revision—is effective at treating post-arthroplasty patellar instability. It has its place in the treatment of patellar dislocation following TKA and its indications must be based on exact analysis of the reasons for the instability. Level of evidenceIV – Retrospective cohort study.

Periprosthetic Femoral Stress Fracture After Bisphosphonate Treatment Resulting in Nonunion Successfully Treated with Teriparatide: A Case Report.

We present the case of a postmenopausal osteoporotic woman, treated with bisphosphonates, who developed a stress fracture at the tip of a revision femoral component, resulting in nonunion after several operative treatment attempts. The nonunion healed after 7 months of subcutaneous injections of 20 μg/day of teriparatide. Teriparatide treatment should be considered for use in recalcitrant stress fractures after total hip arthroplasty.

Femoral revision surgery using a fully hydroxyapatite-coated stem: a cohort study of twenty two to twenty sevenyears.

Femoral component revision with either cemented or proximally coated stems has been disappointing, but revision with extensively coated stems has been promising. Our purpose was to evaluate the long-term outcome using an extensively hydroxyapatite (HA)-coated stem in femoral revisions surgery. During 1988-1993 we performed 66 femoral revisions in 65 patients (49 women), mean age 58 (range, 28-86) years. We used a grit-blasted straight stem made of TiAl6V4 designed for press-fit insertion (Landos Corail; Landanger, Chaumont, France). In 48 hips we used primary stems of size 10 in two cases, size 11 in two, size 12 in seven, size 13 in four, size 14 in 12, size 15 in eight, size 16 in 12 and size 18 in one. In 18 cases, we used revision stems of size 12 in four cases, size 14 in seven, size 16 in five and size 18 in two. During follow-up, 21 patients have died. One patient had a traumatic fracture around the stem after sixyears, and another patient with osteoporosis developed fatigue fracture of the femoral bone after 22years. In one patient the cup loosened after 23years. The cup was revised, but deep infection occurred, and the patient underwent a two-stage revision of both components. Then, 12 of the revised stems were followed for more than tenyears and 24 for more than 20years. During this time only one stem was revised due to mechanical failure. This patient had a femoral defect classified to Type IV, and a proximal fracture occurred when the prosthesis was inserted. The fracture was stabilised by wires, but primary stability of the stem could not be obtained. At control examinations no patients suffered from significant thigh pain, and we noticed a low degree of proximal bone loss and a low incidence of distal bone hypertrophy. Our study suggests that a fully HA-coated stem in femoral revision surgery can provide reliable results for up to 27years. The bone changes confirmed a well-fixed femoral component with a rather physiological transfer of stress from proximal to distal regions with no significant thigh pain.

Medium-term follow-up of 92 femoral component revisions using a third-generation cementing technique

Background and purpose — Very little has been published on the outcome of femoral cemented revisions using a third-generation cementing technique. We report the medium-term outcome of a consecutive series of patients treated in this way.Patients and methods — This study included 92 consecutive cemented femoral revisions performed in our department with a third-generation cementing technique and without instrumented bone impaction grafting between 1996 and 2007. The average age of the patients at revision was 66 (25–92) years. None of the patients were lost to follow-up. At review in December 2013, 55 patients were still alive and had a non-re-revised femoral revision component in situ after a mean follow-up of 11 (5–17) years.Results — The mean preoperative Harris hip score was 50, and improved to 73 at final follow-up. 2 patients died shortly after the revision surgery. 1 stem was re-revised for aseptic loosening; this was also the only case with radiolucent lines in all 7 Gruen zones. A femoral reoperation was performed in 19 hips during follow-up, and in 14 of these 19 reoperations the femoral component was re-revised. Survivorship at 10 years, with femoral re-revision for any reason as the endpoint, was 86% (95% CI: 77–92). However, excluding 8 patients with reinfections after septic index revisions and 1 with hematogenous spread of infection from the survival analysis, the adjusted survival for re-revision for any reason at 10 years was 92% (95% CI: 83–96). With re-revision for aseptic loosening as endpoint, the survival at 10 years was 99% (CI: 90–100).Interpretation — Femoral component revision with a third-generation cemented stem results in acceptable survival after medium-term follow-up. We recommend the use of this technique in femoral revisions with limited loss of bone stock.

Clinical and Radiologic Outcomes of a Fully Hydroxyapatite-Coated Femoral Revision Stem: Excessive Stress Shielding Incidence and its Consequences

Stress shielding remains a concern in total hip arthroplasty. The consequences of stress shielding in hydroxyapatite-coated femoral component revisions were evaluated in a prospective cohort study. A total of 106 patients operated on by revision total hip arthroplasty were identified. Sixty-three patients were eligible for clinical and radiologic assessment of osseointegration, bone remodeling, and stress shielding. Five patients showed evidence of excessive stress shielding. One patient experienced a periprosthetic fracture. No adverse events occurred in the remaining patients with a low rate of thigh pain and reliable osseointegration. This is the only available study concerning mid- to long-term consequences of excessive stress shielding in hydroxyapatite-coated revision stems. We advocate surgeons using these stems to remain vigilant and be aware of possible stress shielding side effects.

CORR Insights(®): High Survivorship With Cementless Stems and Cortical Strut Allografts for Large Femoral Bone Defects in Revision THA.

Where Are We Now? Femoral bone loss is frequently encountered during revision THA. The key is determining the quality and quantity of bone loss, as well as quality and quantity of remaining host bone. In contemporary North American practices, diaphyseal fixation with either an extensively porous-coated stem or titanium modular fluted tapered (TMFT) stem is the standard of care for the majority of hips with bone defects rated Paprosky Type IIIB or less. The basic principle in both techniques is the importance of obtaining immediate axial and rotational stability. The two main clinical concerns with extensively porous-coated stems are intraoperative periprosthetic femoral fracture and stress shielding over time. In response to these concerns, the interest in TMFT stems is increasing, and the indications for their use seem to be expanding [1]. The real controversy is in those patients with Paprosky Type IV defects in whom rotational stability in the diaphysis would not be possible to obtain. In this difficult setting, consideration has traditionally been given to allograft-prosthetic composites (APCs), impaction bone grafting with long cemented stems, proximal femoral replacements, and more recently, TMFT stems. In this intriguing paper by Kim et al., the authors studied 130 patients (140 hips) with Paprosky Type IIIB (54%) and Type IV (46%) defects who underwent revision THA. Even though all patients had less than 2 cm of available isthmic bone, the surgeons used extensively porous-coated stems. However, cortical strut allografts (one strut in 10%, two struts in 75%, and three struts in 15%) were used to provide primary stability for the extensively porous-coated stems. At a mean followup of 16 years, the authors found that all allografts had incorporated, and 87% of stems had radiographic evidence of bony ingrowth. Where Do We Need To Go? When massive bone loss is encountered during revision THA, structural allografts are often a helpful technique. However, followup radiographic analysis of strut incorporation is complicated, and alternative approaches are required to see if these devices are indeed well-fixed. Moreover, deep periprosthetic infection in revision surgery remains a paramount concern to patients and surgeons alike. This may influence the liberal use of struts, particularly in those patients undergo reimplantation THA. Finally, additional investigations comparing the results of patients with prior cemented and uncemented stems are needed given that the remaining host bone quality is starkly different. How Do We Get There? Given the complicated nature of radiographically analyzing strut incorporation, retrieval studies investigating the interface between the cortical strut allograft and an extensively porous-coated stem, as well correlation with radiographic findings, will be helpful in determining where bony ingrowth occurs (if at all). In addition, with infection being one of the most common reasons for femoral component revision, the results of the proposed technique by Kim et al. in septic cases must be studied. Finally, a comprehensive and large-scale analysis of contemporary stems, such as the TMFT stem, will be essential to determine if outcomes vary based upon prerevision diagnosis, particularly between failed cemented and uncemented stems. This will likely require either a multicenter investigation, or large national registries such as the American Joint Replacement Registry, to complete. I suspect that as the body of evidence continues to grow on TMFT stems in Paprosky Type IV defects, their popularity will continue given their larger diameters, as well as the ability to adjust leg length, offset, and version independent of diaphyseal fixation.

The outcome of femoral component revision arthroplasty with impaction allograft bone grafting and a cemented polished Exeter stem: A prospective cohort study of 208 revision arthroplasties with a mean follow-up of ten years.

We report the clinical and radiographic outcomes of 208 consecutive femoral revision arthroplasties performed in 202 patients (119 women, 83 men) between March 1991 and December 2007 using the X-change Femoral Revision System, fresh-frozen morcellised allograft and a cemented polished Exeter stem. All patients were followed prospectively. The mean age of the patients at revision was 65 years (30 to 86). At final review in December 2013 a total of 130 patients with 135 reconstructions (64.9%) were alive and had a non re-revised femoral component after a mean follow-up of 10.6 years (4.7 to 20.9). One patient was lost to follow-up at six years, and their data were included up to this point. Re-operation for any reason was performed in 33 hips (15.9%), in 13 of which the femoral component was re-revised (6.3%). The mean pre-operative Harris hip score was 52 (19 to 95) (n = 73) and improved to 80 (22 to 100) (n = 161) by the last follow-up. Kaplan-Meier survival with femoral re-revision for any reason as the endpoint was 94.9% (95% confidence intervals (CI) 90.2 to 97.4) at ten years; with femoral re-revision for aseptic loosening as the endpoint it was 99.4% (95% CI 95.7 to 99.9); with femoral re-operation for any reason as the endpoint it was 84.5% (95% CI 78.3 to 89.1); and with subsidence ≥ 5 mm it was 87.3% (95% CI 80.5 to 91.8). Femoral revision with the use of impaction allograft bone grafting and a cemented polished stem results in a satisfying survival rate at a mean of ten years' follow-up.

Femoral Component Revision Using a 2nd Generation Modular Femoral Implant

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 5years 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.