Revision total hip arthroplasty with use of a cemented femoral component. Results at a mean of ten years

[Cement in revision arthroplasty-what about the "glacier effect"? : Case studies viewed from different perspectives]

BACKGROUND

The number of operations concerning revision arthroplasty has been increasing continuously in recent years, and it can be assumed that they will continue to increase in the future. If an arthroplasty implant becomes loose, it must be changed. The question often arises as to how the new implant should be fixed in the bone.

ADVANTAGES

Revision implants can be inserted into the bone without cement. In the subsequent period, a secondary osseointegration of the implant takes place. Another possibility is to anchor the implant by using bone cement. The advantage of cemented anchorage is that the implant is firmly fixed in the bone, in principle, immediately, and it is possible to fully load the implant directly. Direct postoperative full weight bearing is helpful, especially for older and multimorbid patients, in order to achieve rapid mobilization.

PREREQUISITES AND CHALLENGES

When using cement in revision cases, however, there are a few prerequisites and challenges that the surgeon should definitely take into account. In the case of revision, the bone in the former implant bed is often deficient and appears thinned and sclerosed. It is, therefore, important to analyze the bone quality preoperatively on radiographic images and to include it in the planning of the anchoring strategy. In addition, the individual bone quality of the patient must also be taken into account intraoperatively. In any case, it must be clarified whether the basic prerequisites for the sufficient bond strength of the cement with the bone to be formed can still be met. Furthermore, the principles of cementing technique must be strictly observed, and the goal of a perfect cement mantle must be aimed for. If the indication for this is overstated, early loosening of the cemented revision arthroplasty is very likely.

The use of a standard-length conical tapered stem in hip revision arthroplasty to address Paprosky type I-II femoral defects: a prospective study of 87 patients

INTRODUCTION

Low-grade femoral defects in revision total hip arthroplasty (rTHA) might be preferably treated with a primary implant. Almost no previous study reported the use of standard-length conical tapered (SLCT) stems in these cases. We analyzed a series of cases using a SLCT stem in rTHA with Paprosky type I-II femoral defects. The purpose of the study was to determine clinical and radiographic outcomes in this series of rTHA.

MATERIALS AND METHODS

We prospectively followed 87 patients undergoing a femoral component rTHA: 53 Paprosky type I and 34 type II femoral defects. Patient-reported measures (Oxford Hip Score, EQ-5D, VAS pain during rest and activity) were administered at baseline, 1 and 2 years post-operatively. Radiographic subsidence overtime was scored. Kaplan-Meier curves were used to evaluate the subsidence over time, the complication-free survival, and the implant survivorship with reoperation and stem revision as endpoints.

RESULTS

The mean follow-up was 72.5 (SD ± 23.9) months. All PROMs significatively improved over time. The average subsidence was 2.8 (SD ± 3.2), 3.6 (SD ± 4.4), and 4.0 (SD ± 4.9) mm at 4, 12, and 24 months respectively. 6 stems had subsidence > 10 mm. The survival without complication was 0.85 (95% CI 0.94-0.77), while the implant survival without reoperation was 0.83 (95% CI 0.95-0.72). The overall stem survival rate was 93.7% (95% CI 0.91-0.97) at 2 years.

CONCLUSION

The use of a SLCT stem in rTHA with Paprosky type I-II femoral defects demonstrated good survival with low subsidence rates during the first 2 years after surgery. Surgeons should consider the use of this primary prosthesis as a potential treatment during stem revision in cases with limited femoral bone loss.

Stay Short or Go Long in Revision Total Hip Arthroplasty With Paprosky Type II Femoral Defects: A Comparative Study With the Use of an Uncemented Distal Fixating Modular Stem and a Primary Monobloc Conical Stem With 5-Year Follow-Up

BACKGROUND

In the revisions for Paprosky type II femoral defects, diaphyseal fixating femoral stems are commonly used. To preserve bone stock, the use of a shorter primary conical stem could be an adequate alternative. The objective of this study is to compare the results of a primary conical stem to the more commonly used diaphyseal fixating modular revision stem in revision total hip arthroplasty surgery with Paprosky type II femoral defects.

METHODS

A total of 59 consecutive patients with Paprosky type II femoral defects from our prospective revision registry were included. Thirty patients who received a long distal fixating modular stem (Revision Stem, Lima Corporate) and 29 patients who received a primary conical short stem (Wagner Cone, Zimmer) were prospectively followed. Minimal follow-up time was 2 years for subsidence and patient-reported outcome measures and 5 years for complications, reoperation, and revision. We compared subsidence, perioperative complications, reoperations, femoral component survival, Oxford Hip Score, EuroQol 5 Dimension, visual analog scale (VAS) for pain at rest, and VAS for pain during activity between stems.

RESULTS

Both groups were comparable regarding demographic, clinical, and surgery-related characteristics. We found more perioperative complications and stem revisions with the modular revision stem than with the primary conical stem. There were no statistical differences in subsidence, EuroQol 5 Dimension, Oxford Hip Score, and VAS for pain at rest or during activity between both stems.

CONCLUSION

In revision total hip arthroplasty with Paprosky type II femoral defects, uncemented primary monobloc conical femoral stems showed the same clinical result as distal fixating modular stems with fewer complications and fewer stem revisions.

Mid- to Long-Term Outcomes of Cementless Modular, Fluted, Tapered Stem for Massive Femoral Bone Loss in Revision Total Hip Arthroplasty

OBJECTIVE

To evaluate mid- to long-term results of revision total hip arthroplasty for massive femoral bone loss using a cementless modular, fluted, tapered stem.

METHODS

This is a retrospective study performed at a single hospital. During the period of January 2007 to January 2015, 33 patients (34 hips) underwent primary revision surgery with cementless modular, fluted, tapered stems due to femoral bone loss. Sixteen men and 17 women were included in the study, with an average age of 63.9 ± 11.7 years (range, 27 to 88 years). Operative data including operative duration, length of incision, drainage volume and duration, blood loss and transfusion, cases of bone graft and extended trochanteric osteotomy were recorded. Clinical evaluation was performed using Harris hip score (HHS), visual analogue scale (VAS), and patients' satisfaction. Radiographic data including femoral stem fixation, subsidence, integrin of allograft bone, and leg length discrepancy were assessed. Complications and survivorship were evaluated using Kaplan-Meier survival rate.

RESULTS

The mean follow-up was 9.1 ± 2.5 years (range, 5-13 years). The Harris hip score was 43.6 ± 11.5 preoperatively and maintained at 86.5 ± 6.6 at the time of latest follow-up (P < 0. 05). The X-ray showed bone ingrowth fixation in 30 hips (88%), fibrous stable fixation in three hips (9%), and instability in one hip (3%). The average stem subsidence was 3.9 ± 2.2 mm (range, 1 to 10 mm). The mean difference in leg length in our study was 3.3 ± 2.7 mm (range, 0 to 10 mm), and the leg length discrepancy in 28 (82%) patients was within 5 mm. No case of junction fracture was observed. Seven (21%) intraoperative fractures occurred in our study. Three (9%) cases with infection were observed after revision. Six (18%) patients had lower limb vein thrombosis. The survivorship of prostheses with re-revision for any reason was 95% (95% CI, 12.0 to 13.0) at the 10-year follow-up. Three (9%) re-revisions were needed, including one for aseptic loosening, one for dislocation, and one for infection.

CONCLUSION

The mid- to long-term results of revision total hip arthroplasty with the cementless modular, fluted, tapered stems are encouraging for massive femoral bone loss.

Outcomes of modular femoral revision implants and the effect of component design on subsidence

AIMS

Femoral revision component subsidence has been identified as predicting early failure in revision hip surgery. This comparative cohort study assessed the potential risk factors of subsidence in two commonly used femoral implant designs.

METHODS

A comparative cohort study was undertaken, analyzing a consecutive series of patients following revision total hip arthroplasties using either a tapered-modular (TM) fluted titanium or a porous-coated cylindrical modular (PCM) titanium femoral component, between April 2006 and May 2018. Clinical and radiological assessment was compared for both treatment cohorts. Risk factors for subsidence were assessed and compared.

RESULTS

In total, 65 TM and 35 PCM cases were included. At mean follow-up of seven years (1 to 13), subsidence was noted in both cohorts during the initial three months postoperatively (p < 0.001) then implants stabilized. Subsidence noted in 58.7% (38/65 cases) of the TM cohort (mean 2.3 mm, SD 3.5 mm) compared to 48.8% (17/35) of PCM cohort (mean 1.9 mm, SD 2.6 mm; p = 0.344). Subsidence of PCM cohort were significantly associated with extended trochanteric osteotomy (ETO) (p < 0.041). Although the ETO was used less frequently in PCM stem cohort (7/35), subsidence was noted in 85% (6/7) of them. Significant improvement of the final mean Oxford Hip Score (OHS) was reported in both treatment groups (p < 0.001).

CONCLUSION

Both modular TM and PCM revision femoral components subsided within the femur. TM implants subsided more frequently than PCM components if the femur was intact but with no difference in clinical outcomes. However, if an ETO is performed then a PCM component will subside significantly more and suggests the use of a TM implant may be advisable. Cite this article: Bone Joint J 2020;102-B(6):709-715.

Radiographic and Clinical Outcomes of Modular Tapered Fluted Stems for Femoral Revision for Paprosky III and IV Femoral Defects or Vancouver B2 and B3 Femoral Fractures

BACKGROUND

Extensive femoral bone loss poses a challenge in revision total hip arthroplasty (rTHA). Many techniques have been developed to address this problem including fully porous cylindrical stems, impaction bone grafting, and cementation of long stems, which have had varied success. Modular tapered fluted femoral stems (MTFS) show favorable results. We sought to determine the minimum 2-year radiographic and clinical performance of MTFS in rTHA in a population with extensive proximal femoral bone loss.

METHODS

Our clinical database was queried retrospectively for all patients who underwent rTHA with an MTFS. We included patients with Paprosky 3 and 4 femoral bone loss and patients with Vancouver B2 and B3 periprosthetic femur fractures. Patients without 2-year follow-up were invited to return to clinic for X-ray evaluation and to complete clinical questionnaires. We assessed distance of stem subsidence and presence of stem fixation on final X-ray. We recorded all-cause revision and survival of the stem at final follow-up.

RESULTS

One hundred twenty-nine patients were available for follow-up. Average follow-up time was 3.75 years. One hundred twenty-two stems (95%) remained in place at final follow-up. Median subsidence was 1.4 mm (range 0-21). All-cause revision rate was 16.3% (21 patients). Of the hips revised, 10 were for instability, 6 for infection, 1 for aseptic loosening, and 1 for periprosthetic femur fracture. Three were revised for other reasons. The stem was revised in 7 patients (5.4%), and the most common reason for stem revision was infection (5 patients). The other 2 stems were revised for aseptic loosening in a Paprosky 4 femur and periprosthetic femur fracture. Survival of tapered modular fluted stems with aseptic failure as an endpoint was 98.4%. The mean Hip disability and Osteoarthritis Outcome Score, Joint Replacement score at final follow-up was 73, and mean Veterans Rand 12 item health survey physical and mental scores were 32.8 and 52.2, respectively.

CONCLUSION

In patients with Paprosky 3, 4 femoral defects or Vancouver type B2, B3 fractures, modular tapered fluted stems for femoral revision show excellent outcomes at minimum 2-year follow-up.

Uncemented or cemented revision stems? Analysis of 2,296 first-time hip revision arthroplasties performed due to aseptic loosening, reported to the Swedish Hip Arthroplasty Register

Background and purpose - Uncemented stems are increasingly used in revision hip arthroplasty, but only a few studies have analyzed the outcomes of uncemented and cemented revision stems in large cohorts of patients. We compared the results of uncemented and cemented revision stems. Patients and methods - 1,668 uncemented and 1,328 cemented revision stems used in first-time revisions due to aseptic loosening between 1999 and 2016 were identified in the Swedish Hip Arthroplasty Register. Kaplan-Meier analysis was used to investigate unadjusted implant survival with re-revision for any reason as the primary outcome. Hazard ratios (HR) for the risk of re-revision were calculated using a Cox regression model adjusted for sex, age, head size, concomitant cup revision, surgical approach at primary and at index revision surgery, and indication for primary total hip arthroplasty. Results - Unadjusted 10-year survival was 85% (95% CI 83-87) for uncemented and 88% (CI 86-90) for cemented revision stems. The adjusted HR for re-revision of uncemented revision stems during the first year after surgery was 1.3 (CI 1.0-1.6), from the second year the HR was 1.1 (CI 0.8-1.4). Uncemented stems were most often re-revised early due to infection and dislocation, whereas cemented stems were mostly re-revised later due to aseptic loosening. Interpretation - Both uncemented and cemented revision stems had satisfactory long-term survival but they differed in their modes of failure. Our conclusions are limited by the fact that femoral bone defect size could not be investigated within the setting of the current study.

Midterm results of the cylindrical fully porous-coated uncemented femoral stem in revision patients with Paprosky I-IIIA femoral defects

INTRODUCTION

The aim of this study was to analyze the survival of the Echelon® femoral stems in revision hip surgeries in patients with Paprosky I-IIIA femoral defects.

PATIENTS AND METHODS

Sixty-six patients (70 hips) who underwent revision hip surgery with at least 3 years of follow-up data were included in the study between 2000 and 2013. The mean patient age was 64.5 (32-83) years, and the mean follow-up period was 93 (45-206) months. The reasons for revision were aseptic loosening in 55 (78.6%) patients, periprosthetic joint infection in 9 (12.9%) patients, periprosthetic fracture in 4 (5.7%) patients, and stem fracture in 2 (2.9%) patients. The preoperative and postoperative follow-up X-rays and functional scores were evaluated.

RESULTS

Five patients died in an average of 70 (45-86) months after surgery due to non-related diseases. We encountered sciatic nerve palsy in two patients and early hip dislocation in two patients, whereas 54 patients were able to walk without any assistive device. The remaining 12 patients required an assistive device to walk. The mean Harris hip score significantly increased from 34 (7-63) preoperatively to 72 (43-96) postoperatively. Aseptic loosening was observed in one patient. The survival of the porous-coated anatomical uncemented femoral stem was 98.4% over 10 years.

CONCLUSION

This study showed that good clinical outcomes and survival can be obtained when using porous-coated anatomical uncemented femoral stems.

Early outcomes after revision total hip arthroplasty with a modern modular femoral revision stem in 65 consecutive cases

Background

We evaluated the early outcomes, including all-cause revisions, aseptic revisions, and reoperations after revision total hip arthroplasty (THA) using a single modern modular femoral stem design.

Methods

A retrospective cohort study on a consecutive series of 62 patients (65 hips) who underwent revision THA with a modern modular femoral stem system, between January 2011 and October 2015, at a single academic medical center was performed. A cumulative incidence competing risk model was used to evaluate the cumulative incidence of failure with death as the competing risk.

Results

The cumulative incidence rate of all-cause revision THA was 14.5% (95% confidence interval [CI], 6%–24%) at 2 years when accounting for the competing risk of death. The rate of aseptic revisions was 6.8% (95% CI, 0.1%–13%), and the rate of all-cause reoperations was 21.6% (95% CI, 11%–31%). Ten THA cases (15%) underwent re-revision THA for any reason: five for infection and five for aseptic failures. The mean time to re-revision was 1 year (range, 0.04–5.34). Patients with a preoperative Mallory classification of 3 or more were at greater risk for reoperation (sub-hazard rate, 3.84; 95% CI, 1.54–9.53; P = .004).

Conclusions

Although the high incidence of reoperation illustrates the complexity of the revision THA population, particularly related to infection and joint instability, the relatively low rate of aseptic failures, minimal radiographic subsidence, and the lack of modular junctional failures suggest that the use of this modular revision THA system may provide adequate fixation and could be considered as a viable treatment option in the setting of revision THA.

Femoral revision with primary cementless stems: a systematic review of the literature

The use of primary cementless stems in femoral revision has gained popularity, but no clear consensus about the correct indication is still present. The aim of our systematic review is to: (1) summarize the available literature focused on the use of cementless primary stem in revision total hip arthroplasty (THA); (2) evaluate whether the use of cementless primary stems could represent a feasible option in hip revision; (3) define the proper indication of this surgical approach. A systematic literature review was performed about the use of cementless primary stems in revision THA. The PRISMA 2009 checklist was considered to edit our review. A total of nine articles were included. The current evidence is primarily Level IV. A total of 439 patients (454 hips) underwent THA revision with primary cementless stem. Partial cementless porous coated stems were used in 246 hips (54.2%). The majority of patients were affected by type I or II Paprosky femoral defects. The mean stem-related survival rate is 95.6% ± 3.8 with a mean follow-up of 4.7 years ± 1.3. Poor standardization of methodological analysis was observed. Current literature shows lacking evidence about primary cementless stems in revision THA. Despite these limitations, we can affirm that primary cementless stems in femoral revision surgery represent a viable option in selected patients. The proper indication is a patient with femoral Paprosky defect types I or II, with low number of previous surgeries and a previous cementless stem.

Studying the effects of primary arthroplasty on post-treatment results among elderly patients with pertrochanteric fracture

Various therapeutic methods are available to treat patients with intertrochantric fracture, which is usually caused by falling down. This complication is usually observed among the elderly, particularly old women. The choice of the proper therapeutic method depends on many factors including patient’s condition, type of fracture, and the amount of movement. Hip arthroplasty is one of these therapeutic methods, which have certain advantages and disadvantages. Immediate resumption of walking with the ability of weight toleration and absence of complications such as aseptic necrosis are some advantages of this method. Sixtyeight elderly patients with pertrochanteric fracture who had resorted to Iranian Army’s hospitals and had undergone arthroplasty. These cases were examined with due comparison with historical and external controls. Variables such a type of operation, age, post-operation pain, the pace of resuming walking ability, embolism, surgical site infection, bedsore and DVT were studied and compared against standard operation. The results achieved through assessment of variables showed a significant difference with standard operation in terms of variables such as post-operative movement ability, pain scale in various times, surgical complications, embolism, surgical site infection, bedsore, and DVT. Post-operative pain within the first 3 months following it are some complications with not much attention is paid to them, but they are important complications which can cause many negative and influential effects on patients. Arthroplasty is more expensive than standard operation and the patient may initially feel more pain.

Long-term results of revision total hip arthroplasty with a cemented femoral component

INTRODUCTION

In revision total hip arthroplasty (THA), the cancellous bone is normally completely removed out of the femoral canal during stem extraction. This situation is comparable to primary THA following the shape-closed concept, with some authors advocating to remove the metaphyseal cancellous bone to enhance press-fit stability ("French paradox"). The aim of this study was to investigate the long-term outcome, regarding survival and radiological results, of a cemented straight stem when used for revision THA and to compare these results to the results of the same stem in primary THA.

MATERIALS AND METHODS

178 stem revisions performed between 01/1994 and 08/2008 using the Virtec straight stem were included. The cumulative incidence for re-revision was calculated using a competing risk model. Risk factors for re-revision of the stem were analyzed using an absolute risk regression model. Radiographs analyzed for osteolysis, debonding and subsidence had a minimum follow-up of 10 years.

RESULTS

The cumulative incidence for re-revision due to aseptic loosening of the stem was 5.5% (95% CI, 2.9-10.2%) at 10 years. Aseptic loosening was associated with younger age, larger defect size and larger stem size. After a minimum 10-year follow-up, osteolysis was seen in 39 of 80 revision THA. Compared to the results in primary THA, the survival in revision THA with the same implant was inferior.

CONCLUSIONS

Cemented straight stems used for revision THA showed excellent long-term results regarding survivorship and radiological outcome. This stem therefore offers a valuable and cost-effective option in revision THA.

Mid- and long-term results of femoral component revision using the cement-in-cement technique: Average 10.8-year follow-up study

BACKGROUND

Few reports are available on the long-term outcomes of femoral component revision by using the cement-in-cement technique. We report the mid- and long-term results of femoral component revision in total hip arthroplasty using the cement-in-cement technique.

METHODS

Between April 1996 and June 2009, 62 consecutive total hip arthroplasties with femoral component revision were performed in 57 patients by using the cement-in-cement technique. We retrospectively reviewed the cases with a follow-up period of at least five years. Three patients died, and two were lost to follow-up. Thus, 52 patients (57 hips), comprising 51 women and one man, were followed for average 10.8 years.

RESULTS

The mean Japanese Orthopaedic Association hip score improved from 57.6 points (range, 28-95 points) preoperatively to 79.8 points (range, 52-98 points) at one year postoperatively and to 77.4 points (range, 59-96 points) at the final follow up. Three revisions of the femoral component were necessary. One of the causes for the revision was a periprosthetic infection that occurred 20 months postoperatively. Another was aseptic loosening that occurred 99 months postoperatively and required revision of the acetabular component. The well-fixed femoral component was revised using the cement-in-cement technique at time of the acetabular revision. The third case was aseptic loosening of the femoral component that occurred 84 months postoperatively. The five-, 10-, and 15-year survival rates for the femoral re-revision due to any reason were 98.4%, 94.0%, and 94.0%, respectively.

CONCLUSION

Use of the cement-in-cement technique for revision total hip arthroplasty resulted in good mid- and long-term radiological and clinical outcomes.

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.].

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.

Femoral revision with a primary cementless stem

INTRODUCTION

The use of a primary cementless component is a tempting option for revision total hip arthrosplasty (reTHA), however, the results of this type of revision have not been clearly determined. The goal of this retrospective study was to determine: if revision with a primary anatomical cementless femoral stem gives adequate bone fixation; the rate of secondary subsidence or recurrent loosening; the survival rate with this device.

HYPOTHESIS

Revision with a primary anatomical cementless femoral stem results in a low rate of subsidence and recurrent loosening.

MATERIALS AND METHODS

This retrospective series of 43 reTHA performed between 1994 and 2012 included 43 patients, mean age 66 years old (37-90) with a minimum follow-up of 24months. There were grade 1 (n=24) or 2A (n=19) bone defects according to the Paprosky classification. The causes of revision were: aseptic loosening in 27, septic loosening in 6, malposition of the implant in 7 and periprosthetic fractures in 3. Clinical (Postel Merle d'Aubigné [PMA] and Harris scores), and radiological (subsidence) assessment was performed, as well as survival analysis (with a 95% confidence interval).

RESULTS

All components were changed through posterolateral approach without femorotomy. In four cases de-escalation (use of a primary component for secondary revision of a prior revision component) was performed. There were no perioperative fractures or perforations. After a mean 47months (24-134), the mean PMA score increased from 10 (5-15) to 16 (11-18), and the Harris score from 58 (20-80) to 85 (66-96). Radiological assessment did not show any extensive radiolucencies or secondary subsidence. Only 3 components were placed in a varus position, with no clinical consequences. One patient had subsequent revision for recurrent dislocations. Estimated survival at 80months by Kaplan-Meier analysis was 85% (CI 95%: 64-100%).

DISCUSSION

There are very few studies in the literature (7 series) on this topic, which shows the reluctance of surgeons to use this technique. Placement of a primary femoral stem requires good metaphyseal bone quality for primary stability. Thus, the indication is limited to Paprosky 1 and 2A stages. Revision surgery must be performed by endofemoral approach requiring good preoperative planning, as well as knowledge of the explanted component and a revision component must be available, if necessary, in the operating room.

LEVEL OF EVIDENCE

Retrospective study, level 4.

REVISION TOTAL HIP ARTHROPLASTY USING A MODULAR CEMENTLESS DISTAL FIXATION PROSTHESIS: THE ZMR(®) HIP SYSTEM. CLINICAL AND RADIOGRAPHIC ANALYSIS OF 30 CASES

Objective: To evaluate the clinical and radiographic results from 30 cases of revision of total hip arthroplasty using a modular cementless distal fixation prosthesis: the ZMR^® Hip System. Method: Between July 2005 and December 2008, 30 operations were performed, on 14 men and 14 women. Two male patients had bilateral surgery. The mean age was 59.2 years (29-81 years), with a mean follow-up of 24 months. The Paprosky classification was used for periprosthetic bone loss, and the Harris Hip Score (HHS) was used to evaluate clinical results. On radiographs, distal migration of the femoral stem was defined in accordance with Sporer. Proximal bone remodeling was classified using the Callaghan criteria. Results: The mean preoperative HHS was 39, and there was a significant increase to 93 points in the final evaluation, which indicated excellent clinical results. No femoral stem migration greater than 5 mm (Sporer) was observed on radiographs, thus suggesting that all the femoral prostheses presented osseointegration and remained stable from the time of the surgery until the final evaluation. The proximal femoral remodeling was either type B or type C in 29 hips, according to Callaghan. Seven patients had complications, but without interfering with osseointegration of the femoral components. Conclusion: Our results from revision of total hip arthroplasty using the ZMR^® Hip System were extremely encouraging, and all the components became osseointegrated and remained fixed at the time of the final evaluation.

Fate of the unrevised cemented stem following cup only revision: 227 hips at an average of 6 years follow-up

BACKGROUND

After primary total hip replacement, aseptic loosening of the acetabular cup is more common than loosening of the femoral stem. Removal of a well-fixed stem adds to operative time, blood loss, risk of bone loss and fracture. There is limited evidence that isolated cup revision can be a safe option in revision hip arthroplasty. We question the following regarding the unrevised cemented stem after isolated cup revision: 1) Does the unrevised stem require revision after isolated cup revision? 2) When is the stem subsequently revised? 3) Why is the stem subsequently revised? 4) Do unrevised stems exhibit radiographic loosening?

HYPOTHESIS

We hypothesise that after isolated cup revision most unrevised stems do not need subsequent revision, and that most do not exhibit evidence of radiographic loosening.

PATIENTS AND METHODS

A retrospective analysis of all patients who underwent revision of the acetabular component only during revision hip arthroplasty between March 1970 and July 2013 was carried out. We assessed survival of the unrevised stem, reasons for subsequent revision, plus radiographic analysis for stem loosening.

RESULTS

Two hundred and twenty-seven hips were included [215 patients with an average age at the time of primary surgery was 47 (13-70) years]. The Charnley stem was used in 161 cases; C-stem 65, Howse 1. Average time between primary surgery and cup revision was 15.9 (1.6-33.4) years. Average follow-up for all stems post-isolated cup revision was 6.1 (0.1-30.7) years. Twenty-eight stems (12.3%) were subsequently revised 5.1 (0.1-12.6) years after the isolated cup revision. Reasons for subsequent revision were: aseptic loosening (10); infection (8); dislocation (6); unreconstructable joint post-loose cup removal (2); fracture (2). Radiographic review was possible on 140 cases. Five femoral stems were revised and 2 others showed evidence of possible radiological loosening but were not revised.

CONCLUSION

To our knowledge this is the largest series showing that isolated cup revision in the place of a well-fixed cemented stem is safe and is associated with ongoing good long-term survival of the stem.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Revision total hip arthroplasty using cemented collarless double-taper femoral components at a mean follow-up of 13 years (8 to 20): an update

The outcome of 219 revision total hip arthroplasties (THAs) in 98 male and 121 female patients, using 137 long length and 82 standard length cemented collarless double-taper femoral stems in 211 patients, with a mean age of 72 years (30 to 90) and mean follow-up of six years (two to 18) have been described previously. We have extended the follow-up to a mean of 13 years (8 to 20) in this cohort of patients in which the pre-operative bone deficiency Paprosky grading was IIIA or worse in 79% and 73% of femurs with long and standard stems, respectively. For the long stem revision group, survival to re-revision for aseptic loosening at 14 years was 97% (95% confidence interval (CI) 91 to 100) and in patients aged > 70 years, survival was 100%. Two patients (two revisions) were lost to follow-up and 86 patients with 88 revisions had died. Worst-case analysis for survival to re-revision for aseptic loosening at 14 years was 95% (95% CI 89 to 100) and 99% (95% CI 96 to 100) for patients aged > 70 years. One additional long stem was classified as loose radiographically but not revised. For the standard stem revision group, survival to re-revision for aseptic loosening at 14 years was 91% (95% CI 83 to 99). No patients were lost to follow-up and 49 patients with 51 hips had died. No additional stems were classified as loose radiographically. Femoral revision using a cemented collarless double-taper stem, particularly with a long length stem, and in patients aged > 70 years, continues to yield excellent results up to 20 years post-operatively, including in hips with considerable femoral metaphyseal bone loss.

Mid-term results of previously cemented hip arthroplasties revised with uncemented modular femoral components: a retrospective study

BACKGROUND

We evaluated the mid-term results of previously cemented hip arthroplasties revised with uncemented modular femoral components.

METHODS

The study included 40 patients (36 females (90 %) and 4 males (10 %), mean age 67.6 years, range 39-87 years) who underwent revision of a previously cemented hip prosthesis with an uncemented modular femoral stem between 2005 and 2009. The indications for revision were femoral aseptic loosening in 38 (95 %) cases and acetabular protrusion in 2 (5 %). According to the Paprosky classification, the femoral defect was type 1 in 10 (25 %) patients, type 2 in 16 (40 %), type 3a in 11 (27.5 %), type 3b in 2 (5 %) and type 4 in 1 (2.5 %). The Harris hip score was used for the clinical evaluation. Femoral vertical subsidence, the cortical index and femoral stem stability were assessed radiologically. The mean follow-up period was 84 months (range 61-95 months).

RESULTS

The mean Harris hip score was 41.4 (range 35.4-44.4) preoperatively and 80.9 (range 65.6-98.3) at the final follow-up examination (p < 0.05). Mean vertical subsidence was 5.7 mm (range 2.5-10.5 mm) in seven (17.5 %) patients. Stable bone fixation was observed in 38 (95 %) patients, fibrous stable fixation in 2 (5 %) and no instability in any patient. Radiographs taken during the early postoperative period revealed that the cortical index was a mean of 1.34 (range 1.11-1.73) and a mean of 1.55 on the final follow-up radiographic examinations (range 1.16-1.91) (p < 0.01).

CONCLUSIONS

Satisfactory results were achieved using uncemented modular femoral components during revision of previously cemented femoral components. Many modular femoral stems provide primary stability by filling femoral bone losses and help determine stem length, offset and anteversion.

Bone remodeling after a mean of 10 years in diaphyseal cortical defects repaired with femoral revision using bypass fixation of extensively porous-coated stems with high stiffness

INTRODUCTION

Femoral component revisions with extensively porous-coated stems have shown promising clinical results, although there are still concerns over stress-shielding.

MATERIALS AND METHODS

We retrospectively reviewed data for 18 patients undergoing femoral component revisions with extensively porous-coated stems with high stiffness. The average length of follow-up was 10 years (range 6-13.7 years).

RESULTS

Radiographic evidence of a bone-ingrown stem was present in 94 % of the hips, and stable fibrous fixation was present in only one hip, but no hips were considered unstable. There was mild stress-shielding in 15 hips, moderate stress-shielding in one hip, and severe stress-shielding in two hips. In one of the latter two hips, stress-shielding was progressive even 8 years after revision surgery. In 12 (92 %) of the 13 hips in which bypass fixation for diaphyseal cortical defects was used, there was good remodeling.

CONCLUSIONS

We suggest that femoral component revision using extensive porous-coated stems is a useful option that may allow for healing of diaphyseal cortical defects.

Long stem cemented revision arthroplasty for aseptic loosening in elderly patients produces good results, despite significant bone loss

We assessed the results of long cemented stems in patients over 65 undergoing a first time revision hip arthroplasty for aseptic loosening. 103 patients were followed up for a minimum of five years after revision surgery; 45% had EndoKlinik C grade preoperative bone loss. At final follow-up 31 patients had died, all but one with the prosthesis in situ. There were 71 revisions alive, one had been revised for a peri-prosthetic fracture. Of the 45 that had radiographs at a minimum of five years, three stems were probably or definitely loose according to the Harris classification. There was 92% patient satisfaction and a mean Oxford Hip Score (OHS) of 25/60 in the 59 patients that had not been revised and had full clinical follow-up. Long-stem cemented revisions for aseptic loosening in elderly patients allow immediate postoperative weight bearing and have good radiological and clinical outcomes.

Minimum 20-year follow-up results of revision total hip arthroplasty with improved cementing technique

A consecutive, non-selective cohort of 83 (77 patients) cemented total hip arthroplasty revisions using contemporary cementing techniques was analyzed at a minimum of 20 years following the index procedure. No patients were lost to follow-up. The average age at revision was 62.4 years (23 to 89). Twenty-two hips (26.5%) had had a reoperation, eighteen (21.7%) for aseptic loosening, 3 (3.6%) for femoral prosthesis fracture and 1 (1.2%) for dislocation. The incidence of re-revision for aseptic femoral loosening was 7.5% and for aseptic acetabular loosening was 21.7%. These results confirm that cemented femoral revision using improved cementing techniques is a durable option in revision hip surgery. In contrast to this, THA revisions using a cemented acetabular component have been less durable at this length of follow-up.

Medium-term outcomes of cemented prostheses and cementless modular prostheses in revision total hip arthroplasty

There is an increasing trend towards cementless modular femoral prostheses for revision hip replacement surgery, especially in patients with severe proximal femoral bone defects. However, for minor femoral bone defects, the benefit of cementless modular is not clear. We designed a retrospective cross-sectional study to compare outcomes of the two femoral implant designs. There were no significant differences in terms of visual analog pain scores, Harris hip scores, femoral bone restoration, stem subsidence, leg length correction, or overall complication rate. Three femoral reoperations (11%) occurred in the cemented group, and two (9%) in the cementless modular group. One femoral stem re-revised (4%) in the cemented group due to recurrent deep infection. Five-year survival for femoral reoperation was 88.2% for patients with the cemented implant and 91.3% for cementless group. Both groups had good clinical and radiological outcomes for femoral revision in patients with minor femoral bone defects during medium-term follow-up.

Results of revision total hip arthroplasty with modular, titanium-tapered femoral stems in severe proximal metaphyseal and diaphyseal bone loss

Evidence supporting modular, tapered stems for severe proximal metaphyseal and diaphyseal bone loss is limited. We report our clinical experience with its use for severely deficient femurs. Of 211 revision total hip arthroplasties (THAs), 18 tapered, modular titanium stems were implanted in Paprosky type III and IV femurs. Clinical data were reviewed for function, stability, structural failure and revision surgery at a mean follow-up of 4.5years. The overall survival rate was 94%. One required revision due to infection and subsidence. The mean subsidence was 3.5mm and the mean pre- and post-operative Harris Hip score was 56 and 79, respectively. In surviving cases, patients achieved satisfactory function and there were no mechanical failures. Modular, tapered stems demonstrated acceptable outcomes for management of severe proximal metaphyseal and diaphyseal defects.

Three to seven year follow-up of a tapered modular femoral prosthesis in revision total hip arthroplasty

PURPOSE

Modular femoral prostheses can provide independent distal fixation and intraoperative flexibility and are being used increasingly, especially in patients with proximal femoral bone defects. This retrospective clinical study evaluated whether modular prostheses were effective and reliable implants for femoral revision.

METHOD

This case series consisted of 58 patients who underwent hip revision with a tapered modular femoral prosthesis at our institution between 2004 and 2008. Mean patient age at surgery was 64 years (range 18-86 years). Femoral bone defects before revision surgery were evaluated using the Paprosky classification. All patients were followed for a minimum of 3 years (mean 4.3 years, range 3-7 years) with clinical and radiographic evaluation. Re-revisions and complications were also recorded.

RESULTS

Two stems required re-revision, one each for recurrent deep infection and periprosthetic fracture. At last follow-up, the Harris Hip Score and Visual Analog Pain Scores had improved significantly, the median radiographic stem migration was 1.6 mm, leg length discrepancy was corrected in 64 % of the patients and osseointegration occurred in 90 %. Complications included intraoperative fracture in 10 (17 %) patients and hip dislocation in 2 (3 %).

CONCLUSION

Modular femoral components can improve hip function, provide distal fixation, equalize leg length, and result in fewer complications when used to revise failed femoral components.

Revision total hip arthroplasty without bone graft of high-grade acetabular defects

Mixed results have been reported with bulk and cancellous bone graft to fill defects during acetabular revision arthroplasty. Jumbo cups have been used to maximize host bone contact, and if adequate initial stability can be achieved, this approach may provide a superior long-term outcome. We retrospectively reviewed a consecutive series of 107 acetabular revisions performed using jumbo cups without bone graft. Bone defects were assessed using a validated radiographic classification system that yielded 64 hips with significant bone defects for inclusion. Mean change in American Academy of Orthopaedic Surgeons lower extremity core and pain scores and in Short Form-12 scores showed increases of 22.01, 37.52, and 17.08 points, respectively. Postoperative radiographs consistently demonstrated host bone ingrowth into the jumbo acetabular shells, except for 3 failures. Careful incremental reaming up to a size that optimizes host bone support and contact may eliminate the need for bone graft in most acetabular revision arthroplasties.

Medium-term outcome of titanium uncemented stems in revision total hip arthroplasty

PURPOSE

To assess the medium-term outcome of titanium uncemented modular tapered stems in revision total hip arthroplasty (THA).

METHODS

A questionnaire was mailed to 421 patients who underwent revision THA using a titanium uncemented modular tapered stem. 66 of whom underwent re-revision THA. The questionnaire was composed to reveal the Charnley classification, the modified 12-item Oxford hip score, and the Devane patient activity level.

RESULTS

323 (77%) of the patients responded. The mean follow-up time was 6.6 years. 12 patients underwent bilateral revision THA. The mean Oxford hip score was 35.7, compared to 35.8 for all-component revision at postoperative month 6 in the New Zealand Joint Registry. The median Oxford hip scores for the subgroups of the stem-only revision (n=92), all-component revision (n=215), and re-revision (n=16) were 38, 39.9, and 30, respectively. The difference was significant between all-component revision and re-revision (adjusted p=0.003), and between stem-only revision and re-revision (adjusted p=0.037). Regarding patient distribution according to the Charnley class and the Devane patient activity level, the difference was significant between the mean Oxford hip scores of Charnley classes B and C (adjusted p=0.017), and between the Devane patient activity levels of Charnley classes A and C (adjusted p=0.043).

CONCLUSION

The medium-term outcome of revision THA using a titanium uncemented modular tapered stem was comparable to that reported for other stems.

Cemented calcar replacement femoral component in revision hybrid total hip arthroplasty

We evaluated intermediate-term to long-term survival of cemented calcar replacement femoral components in hybrid revision total hip arthroplasty. We followed up 52 hips in 50 patients for a mean of 11.4 years. Six (12%) femoral components had been revised: 2 for aseptic loosening, 2 for periprosthetic fracture, and 2 for deep infection. One additional femoral component was definitely loose. The number of previous revision operations (P = .004), preoperatively poorer femoral bone stock (P = .005), and postoperative poor cement mantle grading (P = .003) were significant factors for failure. Kaplan-Meier analysis revealed that the 15-year survival rate was 90% with mechanical failure as the end point. This technique remains a reasonable option for the first-time revision, especially for older and less active patients.

Cement mantle retention: filling the hole

Revision total hip surgery requires a number of techniques that optimizes outcomes while minimizing bone loss. One such technique that has proven useful in revision of the femoral components in revision total hip surgery is leaving an intact cement mantle in place and cementing a new prosthesis within the intact cement mantle. Careful patient selection and preoperative planning are essential for the successful implementation of this technique. The appropriate indications are: (1) if the original stem is broken, but the cement mantle is intact, (2) when removing a well-fixed, cemented stem to improve exposure for an acetabular revision, increase femoral offset, or femoral head diameter, and (3) when removing a debonded femoral component. Although the cement-within-cement revision technique is rarely used, it is an important technique to have in your portfolio. However, it is also important to keep in mind some of the drawbacks of cement-within-revisions and to consider these factors when deciding whether this technique is appropriate for a specific patient.

Primary aseptic revision of the femoral component of a cemented total hip arthroplasty using a cemented technique without bone graft

BACKGROUND

Primary revisions using cement without bone graft reconstruction are less frequently used because of their supposed higher failure rate. The results, in fact, depend on multiple parameters: number of prior revisions, cementing technique quality, and residual bone stock; these intricate factors are rarely taken together into account when analyzing this treatment method.

HYPOTHESIS

Femoral component fixation with cement can be a valid option in total hip arthroplasty primary revision.

OBJECTIVES

The objective of this investigation was to study the long-term results of cemented femoral stems in total hip arthroplasty primary revisions in terms of the quality of the cementing technique and the residual bone stock.

PATIENTS AND METHODS

This is a retrospective study of a series of 80-cemented primary femoral stems revised for aseptic loosening using a new-cemented femoral stem without bone graft. Seventy implants were analyzed at the longest follow-up. The Postel Merle D'Aubigné and the Harris Hip Scores were used for clinical assessment. The French Academy SOFCOT 99 bone loss grading system was used to classify preoperative bone compromise severity. The Barrack classification assessed the quality of the postoperative cementation. The radiographic study at the last follow-up sought signs of femoral implant loosening classified according to Harris.

RESULTS

The mean follow-up was 10 years and 10 months. The functional evaluation of the hip showed a significant overall gain (p<0.0001) after surgical revision. In our series, the existence of severe grade III or IV bone loss on the SOFCOT 99 classification exposed the patient to a significant risk of intraoperative complications (p=0.03). The grade III and IV femurs had a significantly higher risk (p=0.0001) of having type C or D cementation according to the Barrack classification. Type D cementation was a risk factor for significant iterative radiographic loosening (p=0.005) compared to A, B or C cementations. The 10-year survival rate of the femoral implant was 90% (95% confidence interval [95% CI]: 79.2-94.9%). This survival rate was significantly better (p=0.0016) for revisions with type A or B cementations on the Barrack scale (96% survival; 95% CI: 85.1-99%) than for type C or D (70% survival; 95% CI: 41.4-86.1%).

CONCLUSION

This study shows that revised cemented femoral stems without bone graft added are a valid therapeutic option in primary cemented total hip arthroplasty revisions provided that a good-quality cement technique can be achieved. Sufficient bone stock (SOFCOT 99 grade 0, I or II) was indispensable for good cementation.

LEVEL OF EVIDENCE

IV: therapeutic retrospective study.

Large femoral bone loss after hip revision using the uncemented proximally porous-coated Bi-Metric prosthesis: 22 hips followed for a mean of 6 years

BACKGROUND AND PURPOSE

Periprosthetic bone loss after uncemented femoral hip revision is a matter of concern. We have used a proximally porous- and hydroxyapatite-coated prosthesis (Bi-Metric) in revision since 1989 and now we report the bone changes. This prosthesis is intended to distribute the forces more evenly and to avoid proximal femoral unloading.

METHODS

22 patients were unilaterally reoperated because of aseptic loosening. Only patients with a healthy contralateral hip were included. Mean age at revision was 69 (55-80) years. Bone defects were graded by Gustilo-Pasternak and Endo-Klinik classifications. Clinical assessment was performed with Harris hip score. We used radiographs and dual-energy X-ray absorptiometry to evaluate migration, femoral remodeling, and bone mineral density after 72 (30-158) months.

RESULTS

The mean Harris hip score was 74 (30-100) points at follow-up. Mild thigh discomfort was present in 1 patient and moderate thigh pain in 3 patients. There was no loosening or subsidence. Osteolysis seen at revision had diminished in 19 of the 22 hips at follow-up. We noted a large reduction in bone mineral density. It was most pronounced in Gruen regions 1, 2, 6, and 7.

INTERPRETATION

Revision with this stem is a reliable procedure; however, we noted a large degree of proximal bone loss that could lead to later mechanical complications or fractures.

Why revision total hip arthroplasty fails

Current outcomes data on revision total hip arthroplasty focuses on specific implants and techniques rather than more general outcomes. We therefore examined a large consecutive series of failed THAs undergoing revision to determine if survivorship and modes of failure differ in comparison to the current data. We retrospectively reviewed the medical records of 1100 revision THAs. The minimum followup was 2 years (mean, 6 years; range, 0-20.4 years). Eighty-seven percent of revision total hips required no further surgery; however, 141 hips (13%) underwent a second revision at a mean of 3.7 years (range, 0.025-15.9 years). Seventy percent (98 hips) had a second revision for a diagnosis different from that of their index revision, while 30% (43 hips) had a second revision for the same diagnosis. The most common reasons for failure were instability (49 of 141 hips, 35%), aseptic loosening (42 of 141 hips, 30%), osteolysis and/or wear (17 of 141 hips, 12%), infection (17 of 141 hips, 12%), miscellaneous (13 of 141 hips, 9%), and periprosthetic fracture (three of 141 hips, 2%). Survivorship for revision total hip arthroplasty using second revision as endpoint was 82% at 10 years. Aseptic loosening and instability accounted for 65% of these failures.

LEVEL OF EVIDENCE

Level IV, therapeutic (retrospective) study. See the Guidelines for Authors for a complete description of levels of evidence.

A prospective outcomes analysis of femoral component fixation in revision total hip arthroplasty

A prospective, surgeon-allocated, matched cohort analysis of patient outcomes compared cementless, modular metaphyseal and cemented femoral fixation used for revision total hip arthroplasty. First-time femoral revision operations (with and without acetabular revision) with Paprosky types I and II femoral bone stock were included. This series of 86 patients was matched for age, weight, diagnosis, Charnley class, Demand category, femoral bone stock, and outcome measures. At 8-year average follow-up (range, 4-13 years), there were no significant differences in visual analog pain scores (VAPS), Harris Hip Scores (HSS), and SF-36 Physical Function and Bodily Pain scores. One femoral rerevision (2.3%) occurred in the cementless group, and 2 (4.6%) occurred in the cemented group (P = .557). Five-year survivorship for femoral rerevision was 94% for patients with cementless, modular metaphyseal fixation and 92% for patients with cemented fixation. In this study, cementless, modular metaphyseal fixation and cemented femoral fixation were both successful at intermediate-term follow-up in Paprosky types I and II femoral bone (level of evidence: therapeutic study; level II, prospective comparative study).

Use of mesenchymal stem cells to enhance bone formation around revision hip replacements

Tissue engineering approaches to regenerate bone stock in revision total hip replacements could enhance the longevity of the implant and benefit the quality of the patient's life. This study investigated the impaction of allograft with mesenchymal stem cells in an ovine hip hemiarthroplasty model. In total, 10 sheep were divided into two groups with 5 sheep in each group. The groups were: 1) mesenchymal stem cells mixed with allograft; 2) allograft only as a control. Ground reaction force was assessed for limb function and showed that there was no significant difference in the recovery for animals in different groups. The amount of bone regenerated around the hip replacement was assessed using un-decalcified histology. The results showed that the stem cell group generated significantly more new bone at the implant-allograft interface and within the graft than the control group. The results from this study indicate that the use of stem cells on an allograft scaffold increases bone formation indicating that the use of stem cells for revision hip arthroplasty may be beneficial for patients undergoing revision surgery where the bone stock is compromised.

Revision total hip arthroplasty using the Zweymuller femoral stem

BACKGROUND

A variety of femoral stem designs have been reported to be successful in revision total hip arthroplasty without consensus as to optimal design. We evaluated the clinical and radiographic outcomes in a consecutive series of femoral revisions using a wedge-shape, tapered-stem design at medium and long-term follow-up.

MATERIALS AND METHODS

We performed a retrospective review of clinical and radiographic outcomes of twenty-eight consecutive femoral revisions arthroplasties, which were done using the Zweymuller femoral stem.

RESULTS

The mean follow-up was 7.4 years (range 2-15 years). No stem re-revision was necessary. All stems were judged to be stable by radiographic criteria at the most recent follow-up. The final mean Harris hip score was 90. There was no difference in Harris hip scores, implant stability, or radiological appearance (distal cortical hypertrophy or proximal stress shielding) of the implants between medium-term (mean 5.7 years) and long-term (mean 12.4 years) follow-up.

CONCLUSIONS

We found the Zweymuller femoral stem design to be durable for revision hip arthroplasty when there is an intact metaphyseal-diaphyseal junction for adequate press-fit stability at surgery.

[Two-stage procedure to exchange septic total hip arthroplasties with late periprosthetic infection. Early results after implantation of a reverse modular hybrid endoprosthesis]

BACKGROUND

Between January 2001 and January 2005 we performed the exchange of infected total hip arthroplasties in 40 cases.

MATERIAL AND METHODS

We applied a two-stage procedure when implant salvage was not possible. Our treatment algorithm included complete removal of the infected material, thorough débridement, and repeated revisions until cultures were negative. We then implanted a cemented acetabular polyethylene cup with specific antibiotic addition and a cementless modular stem (reverse modular hybrid endoprosthesis). Appropriate intravenous and oral antibiotic therapy was prescribed.

RESULTS

A total of 18 women and 22 men (age 48-86 years) were followed up for 4-48 months (mean: 12 months). Up to now 38 have remained infection free; in two cases the treatment failed and a resection arthroplasty had to be performed. There were eight complications intraoperatively (shaft fractures); four of them were treated conservatively and four needed additional stabilization. The mean hip score improved from 21 points initially to 81 points at the last examination. All details are listed in table form. Two-stage revision hip arthroplasty for infection using the inverse modular hybrid technique seems to be a safe and reliable method. Further investigation and a larger number of patients are necessary to confirm these preliminary results.

Good results with an uncemented proximally HA-coated stem in hip revision surgery: 62 hips followed for 2-13 years

BACKGROUND AND PURPOSE

Proximal bone loss due to stress-shielding is a matter of concern after uncemented femoral hip revision. We have used short, proximally hydroxyapatite-coated prostheses in revision since 1989, and we now report the results.

METHODS

60 patients (62 hips) were revised because of aseptic loosening. Bone defects prior to revision were mostly of type II according to the Gustilo-Pasternak and Endo-Klinik classifications. Follow-up time was 73 (24-161) months. 9 patients had died before follow-up; 8 of these still had the stem in place. Clinical assessment was performed with the Harris hip score. Radiographs were evaluated for bone defects at revision, postoperative stem fixation, and periprosthetic bone remodeling.

RESULTS

Mean Harris hip score was 75 (30-100) points. There was no stem loosening or progressive subsidence. 8 patients had mild to moderate thigh pain. Osteolysis, present at revision, had diminished, partially or completely, in four-fifths of the hips at follow-up. 4 hips had required re-revision due to fracture or dislocation. The 6-year prosthesis survival rate was 95% (95% CI: 0.83-0.98).

INTERPRETATION

Uncemented revision with a short, proximally hydroxyapatite-coated prosthesis is a reliable procedure with encouraging results in the medium term if bone defects at revision are moderate.

Early outcome of a modular femoral component in revision total hip arthroplasty

Forty-six hips in 42 patients underwent revision surgery with a modular femoral component (ZMR; Zimmer, Warsaw, Ind). Thirty-nine hips with 2 to 5 years' follow-up were evaluated radiographically and clinically by the Harris hip score and WOMAC pain/stiffness/function scores. The Harris hip score improved from 47.4 to 72.3 (P<.001), with significant improvements in the WOMAC pain/stiffness/function scores. The mean subsidence was 4.4 mm, with 5 hips demonstrating significant subsidence of more than 5 mm. Four hips required reoperation, 1 due to failure of the femoral component. No early complications were encountered regarding the modular junction. Modular, cementless, extensively porous, coated femoral components have demonstrated early clinical and radiographic success. Distal intramedullary fit helps ensure initial stability; proximal modularity further maximizes fit while optimizing hip offset and length.

Revision total hip replacement using cemented collarless double-taper femoral components

We investigated 219 revisions of total hip replacement (THR) in 211 patients using a collarless double-taper cemented femoral component. The mean age of the patients was 72 years (30 to 90). The 137 long and 82 standard length stems were analysed separately. The mean follow-up was six years (2 to 18), and no patient was lost to follow-up. Survival of the long stems to re-revision for aseptic loosening at nine years was 98% (95% confidence interval (CI) 94 to 100), and for the standard stems was 93% (95% CI 85 to 100). At five years, one long stem was definitely loose radiologically and one standard stem was probably loose. Pre-operative femoral bone deficiency did not influence the results for the long stems, and corrective femoral osteotomy was avoided, as were significant subsidence, major stress shielding and persistent thigh pain. Because of these reliable results, cemented long collarless double-taper femoral components are recommended for routine revision THR in older patients.

Femoral fractures in revision hip surgeries with impacted bone allograft

Impacted allograft bone in hip revision arthroplasty is a biologic reconstruction method that restores bone loss. Periprosthetic femoral fracture is one of the most frequent complications. However, the incidence, types of fracture, time of occurrence, predisposing factors, and whether and how complication affects the reconstruction are unknown. We analyzed 285 femoral revisions performed with this technique. Fractures occurred in 64 patients (22.4%). Fifty-nine of these 64 incidents (92%) occurred during surgery and five within the first postoperative year. Of the 59 intraoperative lesions, 34 were fractures (57.6%) and 25 were incidental perforations (42.3%). Most fractures and incidental perforations were associated with cement removal rather than the reconstructive technique. The reconstruction was compromised in two of the 34 fractures, but the remainder healed without complications. Five patients had a diaphyseal fracture develop within the first postoperative year, four of whom had an intraoperative incidental perforation. There was an increased risk of fractures within the first postoperative year in patients who had an incidental perforation during surgery and in those with severe bone defects. Despite the high rate of femoral complications associated with this reconstructive technique, most did not influence the reconstruction and only the intraoperative and postoperative complete diaphyseal fractures underwent additional treatment.

Ultrasonic tissue characterization for monitoring nanostructured TiO2-induced bone growth

The use of bioactive nanostructured TiO2 has recently been proposed for improving orthopaedic implant adhesion due to its improved biocompatibility with bone, since it induces: (i) osteoblast function, (ii) apatite nucleation and (iii) protein adsorption. The present work focuses on a non-ionizing radiation emitting technique for quantifying in real time the improvement in terms of mechanical properties of the surrounding bone due to the presence of the nanostructured TiO2 prepared by controlled precipitation and acid ageing. The mechanical strength is the ultimate goal of a bone implant and is directly related to the elastic moduli. Ultrasonics are high frequency mechanical waves and are therefore suited for characterizing elastic moduli. As opposed to echographic techniques, which are not correlated to elastic properties and are not able to penetrate bone, a low frequency ultrasonic transmission test is proposed, in which a P-wave is transmitted through the specimen and recorded. The problem is posed as an inverse problem, in which the unknown is a set of parameters that describe the mechanical constants of the sequence of layers. A finite element numerical model that depends on these parameters is used to predict the transformation of the waveform and compare to the measurement. The parameters that best describe the real tissue are obtained by minimizing the discrepancy between the real and numerically predicted waveforms. A sensitivity study to the uncertainties of the model is performed for establishing the feasibility of using this technique to investigate the macroscopic effect on bone growth of nanostructured TiO2 and its beneficial effect on implant adhesion.

Excellent results with femoral revision surgery using an extensively hydroxyapatite-coated stem: 59 patients followed for 10-16 years

BACKGROUND

The outcome of femoral component revision with either cemented or proximally coated stems has been disappointing, but revision with extensively coated stems has been promising. We report long-term outcome of a grit-blasted titanium stem entirely plasma sprayed with hydroxyapatite (HA), in femoral revision surgery.

PATIENTS AND METHODS

During 1988 to 1993, we performed 66 femoral revisions in 65 patients (49 women) aged mean 58 (28-86) years. 3 patients died before the 10-year follow-up and 4 did not come for the follow-up examination because they had no hip problems, as confirmed by telephone and by a written reply. 1 of these, however, was previously controlled at 10 years. Thus, 59 patients (60 hips) were followed by clinical and radiographic analysis for 10-16 years after femoral stem revision.

RESULTS

1 stem was re-revised due to mechanical failure, and none were revised because of infection. We noticed a low degree of proximal bone loss and a low incidence of distal bone hypertrophy. These observations indicate no significant net transfer of stress proximally to distally, and a somewhat physiological weight distribution from the stem to the femoral bone. The bone changes confirmed a well-fixed femoral component in asymptomatic patients.

INTERPRETATION

Our findings indicate good long-term results with a fully HA-coated stem in femoral revision surgery.

Cementless two-staged total hip arthroplasty for deep periprosthetic infection

bTwo-staged exchange with delayed reimplantation of a new prosthesis is considered by many to be the preferred method of treatment for deep periprosthetic infection after total hip arthroplasty. Until recently, most authors of previously published reports of this two-staged exchange procedure have used cemented implants fixed with antibiotic-containing bone cement. In view of the superior results of revision total hip arthroplasties with cementless implants, we reviewed the results of 33 two-staged revision total hip arthroplasties done for deep infection using cementless femoral components. There were no recurrent infections in the 28 patients in this study who had a 2-year minimum followup. Two patients developed a new infection with a different organism after reimplantation of their hip. Three patients with considerable acetabular bone deficiency had acetabular component revision for aseptic loosening; however, there were no cases of femoral component loosening. The overall infection rate of 7% using this approach was comparable to previous reports of two-staged revision total hip arthroplasties done with cemented components fixed with antibiotic-containing bone cement. In addition, cementless femoral component fixation seemed to be more reliable and durable in comparison to previous reports of revision total hip arthroplasty with cemented stems. The results of this study support the continued use of cementless implant fixation for two-staged reconstruction of the infected total hip arthroplasty.

LEVEL OF EVIDENCE

Therapeutic study, Level IV-1 (case series). See the Guidelines for Authors for a complete description of levels of evidence.