Femoral Component In Patients Research Articles

Revision total hip arthroplasty using a modular fluted, tapered revision femoral component and interlocking screws in Vancouver B3 periprosthetic fractures with insufficient bone at the isthmus.

Revision total hip arthroplasty in patients with Vancouver type B3 fractures with Paprosky type IIIA, IIIB, and IV femoral defects are difficult to treat. One option for Paprovsky type IIIB and IV defects involves modular cementless, tapered, revision femoral components in conjunction with distal interlocking screws. The aim of this study was to analyze the rate of reoperations and complications and union of the fracture, subsidence of the stem, mortality, and the clinical outcomes in these patients. A total of 46 femoral components in patients with Vancouver B3 fractures (23 with Paprosky type IIIA, 19 with type IIIB, and four with type IV defects) in 46 patients were revised with a transfemoral approach using a modular, tapered, cementless revision Revitan curved femoral component with distal cone-in-cone fixation and prospectively followed for a mean of 48.8 months (SD 23.9; 24 to 112). The mean age of the patients was 80.4 years (66 to 100). Additional distal interlocking was also used in 23 fractures in which distal cone-in-cone fixation in the isthmus was < 3 cm. One patient (2.2%) died during the first postoperative year. After six months, 43 patients (93.5%) had osseous, and three had fibrous consolidation of the fracture and the bony flap, 42 (91.3%) had bony ingrowth and four had stable fibrous fixation of the stem. No patient had radiolucency around the interlocking screws and no screw broke. One patient had non-progressive subsidence and two had a dislocation. The mean Harris Hip Score increased from of 57.8 points (SD 7.9) three months postoperatively to 76.1 points (SD 10.7) 24 months postoperatively. The 2° tapered, fluted revision femoral component with distal cone-in-cone-fixation, combined with additional distal interlocking in patients with bony deficiency at the isthmus, led to reproducibly good results in patients with a Vancouver B3 fracture and Paprosky type IIIA, IIIB, and IV defects with regard to union of the fracture, subsidence or loosening of the stem, and clinical outcomes.

Assessment of radiolucent lines in patients with lateral unicompartmental knee arthroplasty and the relationship between these lines and the outcome.

To assess the radiolucent lines (RLLs) around both tibial and femoral components in patients following lateral unicompartmental knee arthroplasty (UKA). We performed a retrospective review of the records of a consecutive series of patients who had undergone lateral UKA. The RLLs were assessed with standard anteroposterior and lateral radiographs post-operatively. The patient-reported outcome measures included the Hospital for Special Surgery (HSS) score and Oxford knee score (OKS). The femoral component position (FCP) and femoral-tibial angle (FTA) were also recorded. A total of 198 UKAs that had appropriate radiographs and outcome scores were reviewed with a median follow-up of 33 (range, 12-71) months. The results suggested that 69 cases (34.8%) had RLLs on the standard radiographs. The incidence rates of femoral and tibial physiological RLLs were 11.6% (23/198) and 26% (52/198), respectively, of which 3% (6/198) concerned both components. All RLLs were considered "physiologic lines" that developed within oneyear after surgery. There were no significant differences among the types of RLLs in any of the outcome measures. No differences in FCP (P = .359) or FTA (P = .111) at the last follow-up were seen. It was found that one-third of UKAs had RLLs on radiographs following lateral UKA. All RLLs developed within oneyear after surgery. As a clinical consequence, the development of RLLs does not affect the short-term outcomes after lateral UKA.

A Flexible Intramedullary Guide Can Reduce the Anteroposterior Oversizing of Femoral Components Used in Total Knee Arthroplasty in Patients with Osteoarthritis and Severe Distal Femoral Sagittal Bowing.

Traditionally, a rigid intramedullary rod has been used as the reference guide for femoral cutting in total knee arthroplasty (TKA). However, correct positioning of this rigid rod is difficult, especially in the knees with severe distal femoral sagittal bowing. A flexible intramedullary rod has been developed to address this problem. This study was performed to compare the sagittal alignment and clinical outcomes of TKAs performed with flexible and rigid femoral intramedullary guides. Thirty-eight knees that underwent primary TKAs with flexible intramedullary rods as femoral cutting guides were matched according to patient height and sex with 38 knees that underwent TKAs using conventional rigid rods. Clinical outcomes, including the range of motion and functional scores, and radiological variables, including the distal femoral bowing angle (DFBA), femoral component flexion angle (FFA), and mediolateral overhang and anteroposterior (AP) oversizing of femoral components, were evaluated. Clinical and radiological outcomes did not differ significantly between the flexible rod and conventional rigid rod groups. A subgroup analysis of knees with severe distal femoral sagittal bowing (DFBA >4 degrees) showed that the FFA was significantly larger in the flexible rod group than in the rigid rod group, with an average difference of 3 degrees (5.2 ± 2.4 vs. 2.2 ± 1.6 degrees, respectively, p = 0.022). In addition, the incidence of AP oversizing of femoral components was lower in the flexible rod group than in the rigid rod group (11.1 vs. 60.0%, respectively, p = 0.027). Relative to TKA with a rigid rod, TKA performed with a flexible femoral intramedullary guide resulted in more flexed sagittal alignment of femoral components in patients with severe distal femoral sagittal bowing. This greater flexion of the femoral component resulted in less AP oversizing. However, the use of a flexible rod had no impact on short-term clinical outcomes.

Distal Femoral Rotation is not Associated With Preoperative Proximal Tibial Varus Angle in Patients With Isolated Medial Compartment Osteoarthritis

BackgroundPrior studies have found that greater proximal tibial varus was associated with increased external femoral rotation at time of total knee arthroplasty. These works suggest that measuring the tibial plateau-tibial shaft (TPTS) angle on preoperative weight-bearing long leg radiographs could predict significant variations in the posterior condylar angle. MethodsA minimum of 68 patients were needed to reach 80% power. Patients were included if they had primary medial compartment osteoarthritis and excluded if they had a valgus mechanical axis. The clinical posterior condylar angle (cPCA) was defined as the angle between the anatomic transepicondylar axis and posterior condylar line. Correlation analyses were performed to test for any relationship between the TPTS and cPCA. Two patient groups were created based on TPTS angle: TPTS ≤4° (mild varus) and TPTS >4° (moderate varus). Mechanical axis and rotational measurements were compared between the groups using independent t-tests. ResultsThe mean mechanical axis and TPTS angle were 6.9° and 4.8° of varus, respectively. The mean cPCA was 5.0° (standard deviation [SD], 1.4°; range, 2.4°-7.9°). No correlation was found between the TPTS angle and cPCA (P = .15). The mean cPCA in the mild varus group (n = 28 patients) was 5.2° (SD, 1.5°; range, 2.7°-7.9°), and the mean cPCA in the moderate varus group (n = 45 patients) was 4.4° (SD, 1.7°; range, 0.6°-7.5°). These groups were not statistically significantly different from each other (P = .62). ConclusionThe present study does not support the conclusions of previous works and suggests that the amount of distal femoral rotation cannot be predicted by tibial varus alignment measured on preoperative long leg radiographs. Consequently, we believe that proximal tibial varus should not be used to preoperatively predict external rotation of the femoral component in patients with isolated medial compartment osteoarthritis.

Intentionally Increased Flexion Angle of the Femoral Component in Mobile Bearing Unicompartmental Knee Arthroplasty.

PurposeThe purpose of this study was to determine the results of mobile bearing unicompartmental knee arthroplasty (UKA) with an intentionally increased flexion angle of the femoral component in patients requiring high flexion.Materials and MethodsWe investigated 45 knees treated by UKA. Clinically, we measured the range of motion (ROM) and the American Knee Society (AKS) score preoperatively and at final follow-up and investigated complications. Radiologically, we measured the flexion angle of the femoral component, the posterior slope angle of the tibial component, the femorotibial angle and mechanical axis of the limb postoperatively.ResultsThe ROM was increased from 123° preoperatively to 139° at the final follow-up. The AKS knee and function scores increased from 59 and 68, respectively, preoperatively to 94 and 96, respectively, at the final follow-up. The flexion angle of the femoral component was 9.1°, and the posterior slope angle of the tibial component was 8.6°. There was one case of bearing dislocation in the largest femoral flexion angle case.ConclusionsThe results might reflect the positive effect of an increased flexion angle of the femoral component up to 10° on ROM in mobile bearing UKA, which would contribute to better quality of life after UKA especially in populations requiring deep knee flexion.

Results of the cemented Exeter femoral component in patients under the age of 40 : an update at ten to 20 years' follow-up.

We carried out a further study of the long-term results of the cemented Exeter femoral component in patients under the age of 40 with a mean follow-up of 13.6 years (10 to 20). We reviewed our original cohort of 104 cemented Exeter stems in 78 consecutive patients with a mean age of 31 years (16 to 39). Only one patient was lost to radiological follow-up. A total of six patients (eight hips) had died for reasons unrelated to their surgery. There had been one further periprosthetic fracture from a fall and one fractured femoral stem. No revisions for aseptic loosening were undertaken during the whole study period. Overall, 11 hips had progressive radiolucent lines in one or more zones. The Kaplan Meier survival percentages at ten and 17 years were 97.1% (95% confidence interval (CI) 91.3 to 99.1) and 92.1% (95% CI 74.1 to 97.8) with revision for any reason as the endpoint, and 100% at both ten and 17 years with aseptic loosening (95% CI 83.8 to 100) as the endpoint. No additional hips were classified as radiologically loose. The Exeter femoral component continues to function satisfactorily in young patients for up to 17 years after surgery. Cite this article: Bone Joint J 2017;99-B:192-8.

Computer-assisted surgery does not improve the rotational alignment of the femoral component in total knee arthroplasty for severe genu varus deformity

Background: Accurate femoral rotational alignment is critical for successful total knee arthroplasty (TKA). Debates exist about whether computer-assisted surgery-TKA (CAS-TKA) improves the accuracy of femoral rotational alignment. We hypothesize that it is related to the severity of the preoperative genu varus deformity and that CAS-TKA is beneficial under certain circumstances. Methods: Patients who had osteoarthritis with genu varus deformity and underwent conventional TKA or CAS-TKA between January 2007 and July 2013 at our hospital were enrolled. Based on the degree of preoperative deviation from the mechanical axis (MA), the patients were divided into three subgroups at 5-degree intervals: (1) varus deformity of ＜ 10 degrees, (2) 10–14.9 degrees, and (3) ≥ 15 degrees. Computed tomography was used to determine whether CAS-TKA provided better femoral rotational alignment than did conventional TKA. Component and limb alignment were also radiographically compared. Results: One hundred seventy-three knees on 128 patients met the inclusion criteria. For patients in the ＜ 10 degrees and 10–14.9 degrees groups, the component alignments and postoperative mechanical axes were not significantly different between conventional and CSA-TKA. For patients in the ≥ 15 degrees group, however, the femoral flexion angle was significantly (p ＜ 0.001) better for CSA-TKA, but not for the femoral valgus, tibial valgus, tibial flexion, or femoral rotational angles. Conclusions: CAS-TKA does not improve the accuracy of rotational alignment of the femoral component in patients with genu varus deformity. Level of Evidence: Therapeutic Level III.

Total Hip Arthroplasty With an Uncemented Tapered Femoral Component in Patients Younger Than 50 Years of Age: A Minimum 20-Year Follow-Up Study

BackgroundPreviously, we reported the mean 16-year results of primary uncemented total hip arthroplasty using a tapered femoral component in patients <50 years. The purpose of this study was to update our previous report using the Taperloc femoral component in young patients who had been followed for a minimum of 20 years postoperatively. MethodsBetween 1983 and 1990, 108 consecutive uncemented total hip arthroplasties were performed in 91 patients of age <50 years, with use of the Taperloc femoral component. Every patient was followed for a minimum of 20 years after surgery or until death. At a mean of 25 (range, 20-29 years) postoperatively, 76 patients (91 hips) were living. The Harris Hip Score, radiographic results, complications, and Kaplan-Meier survivorship were evaluated. ResultsIn the entire cohort of 108 hips, 9 femoral components (8%) have been revised, none for aseptic loosening. Five well-fixed stems were removed during acetabular revision, 3 stems were revised for infection, and 1 stem was exchanged because of a peroneal nerve palsy. Distal femoral osteolysis was identified around 1 hip. With failure defined as stem removal for any reason, implant survival was 90% (CI = 82-95) at 29 years. With failure defined as stem removal for aseptic loosening, implant survival was 100% at 29 years. ConclusionPrimary total hip arthroplasty with the Taperloc femoral component in young patients was associated with a high rate of survival at 29 years.

Can a Conical Implant Successfully Address Complex Anatomy in Primary THA? Radiographs and Hip Scores at Early Followup.

Total hip arthroplasty (THA) in patients with small or abnormal proximal femoral anatomy is challenging as a result of complex anatomic deformities in the hip. It is unclear which stem is the most appropriate for these patients. One possible implant design that may help meet this need is the modified Wagner Cone prosthesis, whose design consists of monoblock cone with splines; however, to our knowledge, no clinical results have been published using this implant. We evaluated the hip scores and radiographic results (including signs of osseointegration and subsidence) of complex primary THA using the modified Wagner Cone cementless femoral component in patients with small or abnormal proximal femoral anatomic proportions. Between 2006 and 2011, we performed 59 THAs on patients whose femoral geometry precluded the use of standard-sized implants. Of these, 49 (83%) received the modified Wagner Cone prosthesis. During this time, our indications for use of the Wagner Cone implant in such patients included: femoral neck retroversion, excessive anteversion of the femoral neck, or small proximal femora not suitable for standard implants. Of those, 40 patients with 49 THAs were available for radiographic and clinical followup at a minimum of 3 years, and no patients were lost to followup. The diagnosis included developmental dysplasia of hip (22 patients, 28 hips), secondary trauma or posttuberculosis osteoarthritis (nine patients, 10 hips), and hip disease secondary to other disorders (eight patients, nine hips) and osteonecrosis (one patients, two hips). Two versions of the stem with 135° (28 hips) or 125° (21 hips) neck angle versions were used to reestablish normal hip biomechanics. Version angle was chosen based on preoperative templating. Cementless cups with screws were used for the acetabulum. Mean followup was 4 years (range, 3-7 years). Study endpoints were the Harris hip score and radiographic evaluations by a surgeon not involved in the clinical care of the patients (QZ); radiographic analysis included evaluating for the presence or absence of signs of osseointegration (including Engh's criteria) and subsidence. The Harris hip score improved from a mean of 41 ± 9 preoperatively to a mean of 85 ± 10 at last followup (p < 0.01). The mean vertical subsidence was 1.5 ± 1.1 mm. Radiographic evaluation demonstrated stability (no further subsidence) of all implants at last followup. Endosteal spot welds were found in 32 hips (65%). No progressive radiolucencies were observed. One patient (one hip) underwent revision surgery as a result of late infection; no other revisions were performed. The modified Wagner Cone femoral stem has provided improvements in hip scores and promising short-term radiographic results at short-term followup in complex cementless THA associated with abnormal or small femoral anatomical proportions in which standard implants are inappropriate. Longer followup will be needed to see if these results endure. Randomized trials are needed to determine the optimal stem design for these patients. Level IV, therapeutic study.

Survivorship of the cementless Spotorno femoral component in patients under 50 years of age at a mean follow-up of 18.4 years.

The long-term survival of the cementless Spotorno CLS femoral component in patients aged > 50 years at the time of arthroplasty was investigated. Survivorship analysis of a consecutive series of 85 patients (100 hips; under 50 years of age at a mean follow-up of 18.4 years (16.3 to 20.8)) was performed. The clinical and radiographic outcomes were satisfactory. The overall rate of survival of the femoral component was 93.5% (95% confidence interval (CI), 90.9 to 96.1) after 19 years. Survival with revision for aseptic loosening as the end point was 95.7% (95% CI 93.6 to 97.8%) at 19 years. This study demonstrates an excellent long-term survival of the Spotorno CLS femoral component after 16 to 20 years in young patients undergoing total hip arthroplasty.

Revision hip arthroplasty in patients with a previous total hip replacement for osteonecrosis of the femoral head.

Patients with osteonecrosis of the femoral head are typically relatively young and active and often require high rates of revision after primary total hip arthroplasty. However, outcomes of revision hip arthroplasty in this patient population have rarely been reported in the literature. The authors conducted a retrospective review of 72 patients (75 hips) who underwent revision hip arthroplasty with a primary diagnosis of osteonecrosis of the femoral head. Mean age at index revision was 53.3 years (range, 34-76). Components of acetabular revision included a cementless porous-coated cup in 58 hips and an acetabular cage in 3 hips. Components of femoral revision included a fully grit-blasted tapered stem in 30 hips and a proximally porous-coated modular stem in 9 hips. Mean duration of follow-up was 7 years (range, 3-17). Mean Harris Hip Score improved from 49 points preoperatively to 90 points postoperatively. At final follow-up, 11 hips (14.7%) required reoperation because of aseptic loosening (6 hips), infection (2 hips), recurrent dislocation (1 hip), periprosthetic fracture (1 hip), and ceramic fracture (1 hip). Kaplan-Meier survivor-ship with an endpoint of re-revision for any reason was 81% and for mechanical failure was 87.5% for the cup and 100% for the stem at 10 years. Unlike the previous report, the authors' study showed a lower failure rate of the femoral stem after revision hip arthroplasty using modern cementless femoral components in patients with osteonecrosis of the femoral head. Aseptic cup loosening or osteolysis is the most common mechanism of failure at medium-term follow-up.

External rotation of the femoral component decreases patellofemoral contact stress in total knee arthroplasty.

The purpose of this study was to investigate the relationship between patellofemoral (PF) contact stress in vivo and the alignment of the femoral component in patients after total knee arthroplasty (TKA). Thirty knees with medial compartment osteoarthritis that underwent mobile-bearing TKA with modified gap technique were evaluated. Surgery was performed using a subvastus approach to eliminate the effect of the approach to muscle balance, with a computed tomography-based navigation system (Vector Vision 1.61; Brain Lab, Heimstetten, Germany). PF contact stress was measured by a Flexiforce pressure sensor (Nitta Co., Ltd., Osaka, Japan) intraoperatively, and the results were compared with the alignment of the femoral component after TKA. The PF contact stress was not correlated with sagittal and coronal alignment of the femoral component and patellar tracking, whereas rotational alignment of the femoral component was negatively correlated with PF contact stress (r = -0.718, p < 0.01). Regarding the alignment of the femoral component, only the rotational alignment of the femoral component was correlated with PF contact stress. PF contact stress decreased more as the femoral component rotated more externally. Case control study, Level III.

Evaluation of the results from proximal fixation of uncemented conical femoral components in Dorr type C femurs

ObjectiveTo evaluate the results from proximal fixation of uncemented conical femoral components in patients with a type C proximal femur and compare them with the results obtained from type A and B femurs. MethodsThis was a retrospective study on 87 patients with 90 uncemented total hip arthroplasty procedures. Three patients (three hips) were excluded because their follow-up lasted for less than two years. The follow-up ranged from 2 to 4.3 years and the mean was 2.8 years. The Bicontact femoral implant model was used. The preoperative radiographs were evaluated, the femurs were classified as Dorr types A, B or C and the cortical indices were measured. The patients were evaluated clinically by means of the Harris Hip Score (HHS), before the surgery and at the last follow-up. The sequences of postoperative radiographs were compared regarding stability, complications and any signs of osseointegration of the femoral prosthesis. ResultsAmong the 87 hips with follow-up greater than two years, 32 femurs were type A (37%), 37 type B (42%) and 18 type C (21%). Before the operation, the mean HHS was 39.4 for types A and B and 38.8 for type C. At the last follow-up, the mean HHS was 89.8 for types A and B and 86 for type C. None of the 87 femoral components had been revised by the time of the last follow-up; all of them were considered stable. In 86 cases, the radiographs showed signs of osseointegration. ConclusionThere were no significant differences in the clinical results or in the fixation (and osseointegration) of conical uncemented femoral prostheses with proximal porosity, among femurs with different types of femoral morphology according to the Dorr classification. This conclusion may vary if another implant model were to be used.

Avaliação dos resultados de componente femoral cônico de fixação proximal não cimentado em fêmur tipo C de Dorr

Objectiveto evaluate the results from proximal fixation of uncemented conical femoral components in patients with a type C proximal femur and compare them with the results obtained from type A and B femurs. Methodsthis was a retrospective study on 87 patients with 90 uncemented total hip arthroplasty procedures. Three patients (three hips) were excluded because their follow‐up lasted for less than two years. The follow‐up ranged from 2 to 4.3 years and the mean was 2.8 years. The Bicontact femoral implant model was used. The preoperative radiographs were evaluated, the femurs were classified as Dorr types A, B or C and the cortical indices were measured. The patients were evaluated clinically by means of the Harris Hip Score (HHS), before the surgery and at the last follow‐up. The sequences of postoperative radiographs were compared regarding stability, complications and any signs of osseointegration of the femoral prosthesis. Resultsamong the 87 hips with follow‐up greater than two years, 32 femurs were type A (37%), 37 type B (42%) and 18 type C (21%). Before the operation, the mean HHS was 39.4 for types A and B and 38.8 for type C. At the last follow‐up, the mean HHS was 89.8 for types A and B and 86 for type C. None of the 87 femoral components had been revised by the time of the last follow‐up; all of them were considered stable. In 86 cases, the radiographs showed signs of osseointegration. Conclusionthere were no significant differences in the clinical results or in the fixation (and osseointegration) of conical uncemented femoral prostheses with proximal porosity, among femurs with different types of femoral morphology according to the Dorr classification. This conclusion may vary if another implant model were to be used.

MRI After Patellofemoral Replacement: the Component–Bone Interface and Rotational Alignment

In an earlier paper, it was shown that tailored magnetic resonance imaging (MRI) allows for reproducible analysis of the preserved knee joint structures after patellofemoral replacement (PFR). This pilot study investigates to what degree MRI could produce reliable assessment of the implant-bone interface of femoral and patellar components and rotational alignment following PFR. MRI tailored for reduction of metallic artefacts was performed in seven patients who had undergone PFR. Two independent investigators evaluated the implant-bone interface at femoral and patellar components and the rotational alignment of the femoral component. They also assessed their degree of confidence in evaluation using a five-point scale. The inter-observer reliability was determined. Implant-induced MRI artefact was barely observed and there was no interference with component-bone interface evaluation. There was excellent inter-observer reliability, inter-observer agreement, and confidence for the implant-bone interface at femoral and patellar components and for rotational alignment. The applied score for the interface was found to be reliable. Tailored MRI allows reproducible analysis of the implant-bone interface and of rotational alignment of the femoral component in patients who have had PFR. It might prove helpful in the assessment of painful PFR.

Complications of Cemented Long-stem Hip Arthroplasty in Metastatic Bone Disease Revisited

The literature suggests that a cemented long-stem femoral arthroplasty is associated with increased intraoperative and perioperative risks. Embolic events may precipitate cardiopulmonary complications and even death; by contrast, others have reported that the use of a cemented long-stem femoral arthroplasty in patients with metastatic bone disease is a safe procedure. Specifically, in this study, we sought to identify (1) intraoperative complications potentially attributable to the use of cemented long-stem femoral components, and (2) early postoperative complications potentially attributable to the use of cemented long-stem femoral components in patients having an arthroplasty for metastatic bone disease. In this study, we performed a retrospective chart review of 42 patients (44 arthroplasties), in which the same surgical technique was used. The primary outcome measure was perioperative complications, including intraoperative cement-associated desaturation, cement-associated hypotension, sympathomimetic administration, postoperative hypotension/desaturation, and death. In this series, 19% of the patients had cement-associated hypotension and sympathomimetics were administered to 48%. Two patients required prolonged intubation. One death occurred during hospitalization but there were no cardiopulmonary events. This study showed that some patients experienced postoperative desaturation, prolonged intubation, and increased use of sympathomimetics, however, these events were short-lived and did not result in patient mortality. Although there are significant risks to cemented long-stem femoral arthroplasty, it can be performed with a low risk of fatal cardiopulmonary complications and remains a surgical option when treating patients with metastatic bone disease. Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Biomechanical comparisons between a new avascular necrosis of femaral head stem based on Chinese patients with avascular necrosis and two other designs

Background There is a relatively high failure rate of the femoral component in patients with avascular necrosis at the intermediate-term follow-up. Improving the geometrical fit of the femoral stem against the medullary canal may help to provide long-term survivorship of the hip replacement for patients with avascular necrosis. Methods We designed a specific stem, based on morphometric studies of proximal femoral canals in Chinese avascular necrosis patients and evaluated the stem by finite element analyses, comparing the novel stem with two commercially available and commonly used stems. Results The morphometric data from avascular necrosis patients showed specific geometric differences in the proximal femoral canal, including profile curves in both the sagittal and coronary planes than the patients with femoral neck fracture. The shorter stemmed prostheses (Fitmore® and our stem) performed better than the longer stemmed prosthesis (VerSys®). Conclusions This is the first study to investigate the femoral geometries of Chinese avascular necrosis patients. Our stem provides better stability and is theoretically beneficial to bone ingrowth, which may increase the long-term stability and fixation of the implant.

Long-term results of cementless femoral reconstruction following intertrochanteric osteotomy

The objective of this retrospective cohort study was to assess the long-term outcome of cementless femoral reconstruction in patients with previous intertrochanteric osteotomy (ITO). We evaluated the clinical and radiographic results of a consecutive series of 45 patients (48 hips, mean age 50years) who had undergone conversion hip replacement following ITO with a cementless, grit-blasted, double-tapered femoral component. Clinical outcome was determined using the Harris hip score. Stem survival for different end points was assessed using Kaplan-Meier survivorship analysis. At a mean follow-up of 20 (range, 16-24) years, 11 patients (12 hips) had died, and no patient was lost to follow-up. Six patients (six hips) underwent femoral revision, two for infection, three for aseptic loosening and one for periprosthetic fracture. Mean Harris hip score at final follow-up was 78 points (range, 23-100 points). Stem survival for all revisions was 89% (95%CI, 75-95) at 20years, and survival for aseptic loosening was 93% (95%CI, 80-98). The long-term results with this type of cementless femoral component in patients with previous intertrochanteric osteotomy are encouraging and compare well to those achieved in patients with normal femoral anatomy.

Cementless Total Hip Arthroplasty Using a Modular Femoral Component in Patients with Femoral Head Osteonecrosis: Comparison of Metal-on-Metal and Ceramic-on-Ceramic Articulation

� Purpose: The purpose of this study was to evaluate the clinical and radiological outcomes after total hip arthroplasty using the S-ROM modular system for osteonecrosis of the femoral head, and to compare the results between the groups using metal-on-metal articulation and ceramic-on-ceramic articulation. Materials and Methods: Sixty-six patients (78 hips) with osteonecrosis of the femoral head were evaluated after primary total hip arthroplasty between January 2001 and December 2004, using an S-ROM proximal modular femoral stem. The average follow-up was 77 months (range, 60 to 122 months) and all patients were followed for more than five years. Results: The average Harris hip score improved from 53 points to 88.5 points at the final follow-up. At the latest radiologic evaluation, sixty-seven stems had bony ingrowth stability, and 10 stems had stable fibrous ingrowth. However, one stem had diffuse extensive osteolysis and loosening, which was revised at 9 years. Postoperative complications included 4 cases of heterotrophic ossificiation, 1 case of linear fracture after insertion of the femoral stem, 1 case of dislocation, 2 cases of infection, and 1 case of extensive osteolysis and loosening. There were 3 cases of revision and Kaplan-Meier survivorship analysis with revision estimated at a 95.7% chance of survival for the femoral component during 122 months. Conclusion: Our study showed that total hip arthroplasty using the S-ROM modular system with metal-on-metal articulation or ceramic-on-ceramic articulation had favorable clinical and radiological mid- to long-term results.

Does cementing the femoral component increase the risk of peri-operative mortality for patients having replacement surgery for a fracture of the neck of femur?

Concerns have been reported to the United Kingdom National Patient Safety Agency, warning that cementing the femoral component during hip replacement surgery for fracture of the proximal femur may increase peri-operative mortality. The National Hip Fracture Database collects demographic and outcome data about patients with a fracture of the proximal femur from over 100 participating hospitals in the United Kingdom. We conducted a mixed effects logistic regression analysis of this dataset to determine whether peri-operative mortality was increased in patients who had undergone either hemiarthroplasty or total hip replacement using a cemented femoral component. A total of 16,496 patients from 129 hospitals were included in the analysis, which showed a small but significant adjusted survival benefit associated with cementing (odds ratio 0.83, 95% confidence interval 0.72 to 0.96). Other statistically significant variables in predicting death at discharge, listed in order of magnitude of effect, were gender, American Society of Anesthesiologists grade, age, walking accompanied outdoors and arthroplasty. Interaction terms between cementing and these other variables were sequentially added to, but did not improve, the model. This study has not shown an increase in peri-operative mortality as a result of cementing the femoral component in patients requiring hip replacement following fracture of the proximal femur.