Revision total hip arthroplasty using a cementless modular femoral hip design

The difficulty in selecting the "ideal" components for revision total hip arthroplasty is one factor leading to poor outcomes. For femoral hip components, loosening rates of femoral revision have been reported with different types of designs. Because of improved rates with more porous components, the use of cementless femoral revision is highly attractive. This article describes a cementless femoral revision component, the ZMR system, which addresses the challenges and design goals of revision as well as surgical philosophy: off-the-shelf flexibility, proximal-distal extensive fixation, restoration of kinematics (offset, let lengths, anteversion, and muscle tensioning), and implant integrity.     

Simultaneous bilateral total hip arthroplasty with a cementless femoral stem

Simultaneous bilateral total hip arthroplasty (THA) is an increasingly common procedure. Although use of a cementless stem can eliminate cement complications, some surgeons limit application of cementless THA because of concerns about early implant loosening. In this article, we report on 30 cementless THA cases (15 patients) followed up for a minimum of 2 years (range, 26-50 months). Despite 73% of femoral bone being type B or type C, all stems showed stable bone ingrowth fixation and no evidence of subsidence. Polyethylene wear rates (left, 0.154 mm/y; right, 0.114 mm/y) did not differ significantly. The excellent clinical results obtained with simultaneous bilateral cementless THA are comparable with those obtained with unilateral THA.     

Revision of total hip arthroplasty using an anterior cortical window, extensive strut allografts, and an impaction graft: follow-up study

PURPOSE: To report the outcome of revised total hip arthroplasty procedures involving an anterior cortical window, extensive strut allografts, and an Exeter impaction graft. METHOD: Eight patients (9 hips) with a mean age of 58 years underwent revision of total hip arthroplasty using the Exeter hip impaction graft system and strut allografts between 1995 and 1998. An extensile anterior approach was used, and an anterior cortical window was created in the femur, to remove the old implant. External strut allografts were attached by wires to provide cortical support. The mean follow-up duration was 74 months. Indications for surgery were aseptic loosening of previous implants in 8 hips and infection of one hip that had previously undergone total arthroplasty. RESULTS: 19 Dall Miles cables, 4 ordinary cerclage wires, and 8 cerclage wires tightened with the clincher knot technique were used to secure the allograft to the host bone. The strut grafts were found to be incorporated in all cases. No wires became loose. One patient developed 20 degrees of angulation at the allograft-host bone junction. Using the method of Fowler and Gie, we found that one femoral implant had subsided 2 mm within the cement mantle. Two other implants had 1 mm of subsidence at the cement bone interface, and one patient had a major subsidence of 15 mm that required revision. CONCLUSION: Using an anterior cortical window in the femur to remove the old implant does not predispose to failure of the allograft to incorporate into the host bone.     

Revision total hip arthroplasty using a tapered, press-fit cementless revision stem in elderly patients

In elderly patients, osteoporosis can complicate revision total hip arthroplasty (THA). The SLR-Plus (Smith & Nephew, Memphis, TN) revision stem has a tapered, press-fit design, which we hypothesized could enhance stability in this population. Accordingly, we retrospectively analyzed data for 48 elderly patients who underwent revision THA using the SLR-Plus stem. The patients had a mean age of 66.5 years (range, 60-81 years) at surgery. They were monitored for a mean of 5.6 years (range, 3.4-8.0 years) after surgery. The mean Harris Hip Score improved from 67.8 to 91.6. No infection, dislocation, osteolysis, or stress shielding around stem were observed after surgery. The survivorship at an average of 5.6-year follow-up was 98%. These favorable results indicate that the SLR-Plus stem is useful in revision THA in elderly patients.     

Revision total hip arthroplasty using a cementless acetabular component: technique and results

One hundred thirty-eight acetabular revisions for aseptic loosening were performed in 132 patients using a cementless hemispherical component coated with titanium mesh and inserted with supplemental screw fixation. Twelve patients died, 9 were lost to follow-up and 6 could not return, leaving 111 patients (115 hips) at mean 100 months follow-up. Thirteen hips required revision (11%); 4 for recurrent dislocations, 6 for sepsis, and 3 stable cups were revised (at the time of stem revision). No cup was revised for aseptic loosening. Radiographic review was available for 105 patients (109 hips) at mean 98 month follow-up (78 to 135 months). One hundred cups (91%) were considered stable. Seven cups were possibly unstable (7%), one cup was probably unstable (1%), and one septic hip had an unstable cup (1%). Four percent of the cups showed a complete radiolucency. A partial progressive radiolucency was seen in 3%, a partial nonprogressive radiolucency in 54%, and no radiolucency was present in 39%. A screw radiolucency was seen in 2%, and osteolysis at the cup margin in 4%. Revision of the acetabulum with a cementless porous-coated hemispherical fiber-metal component seems to be superior to the results reported for acetabular revisions with cement at similar follow-up.     

Analysis and results of total hip replacement with femoral cortical fixation

The present report describes an original conception of a total hip prosthesis. The implant is applied upon the lateral cortical of the shaft of the femur. The implant is screwed on by the mean of a plate. There is no adjunction of cement. The design tries to reach as close a possible the natural physiology of a long bone during life. The purpose is to gain a better longevity of the implant and, consequently, its utilisation to young patients for whom a total hip prosthesis is the only solution.     

The anatomically difficult primary total hip replacement: medium- to long-term results using a cementless odular stem

This prospective study presents the ten-year (5 to 16) clinical and radiological results of 55 primary total hip replacements (THR) using a cementless modular femoral component (S-ROM). All patients had a significant anatomical abnormality which rendered the primary THR difficult. The mean Harris hip score was 36 (12 to 72) pre-operatively, 83 (44 to 100) at five years, and 85 (45 to 99) at ten years. The Western Ontario and McMaster Universities osteoarthritis index (WOMAC) and short-form (SF)-12 scores were recorded from the year 2000. The mean SF-12 score at five years after surgery was 45.24 (22.74 to 56.58) for the physical component and 54.14 (29.20 to 66.61) for the mental component. By ten years the SF-12 scores were 42.86 (21.59 to 58.95) and 51.03 (33.78 to 61.40), respectively. The mean WOMAC score at five years post-operatively was 25 (0 to 59), and at ten years was 27 (2 to 70). No femoral components were radiologically loose, although five had osteolysis in Gruen zone 1, three had osteolysis in zone 7, and two showed osteolysis in both zones 1 and 7. No osteolysis was observed around or distal to the prosthetic sleeve. No femoral components were revised, although three hips underwent an acetabular revision and two required a liner exchange. At a mean of ten years' follow-up the S-ROM femoral component implanted for an anatomically difficult primary THR has excellent clinical and radiological results.     

Revision of failed total hip arthroplasty with a proximal femoral modular cemented stem

We have designed a modular cemented femoral component for revision of failed total hip arthroplasty in which deficiency of the proximal femur is such as to require a variable extrafemoral portion of the stem. We present the results of the first 74 operations in 72 patients; 56 of the patients had grade-3 or grade-4 femoral deficiency as defined by Gustilo and Pasternak and 24 had fractures of the proximal femur, of which 22 were periprosthetic. There was or had been infection in 19 hips. At a mean follow-up of 5 years 9 months (1 to 12 years) nine stems were radiologically loose of which three had been revised. There were no failures in 45 cases in which there was fixation of the distal stem of 10 cm or more. Dislocation occurred in nine patients and there were four cases of infection in the 19 which were, or had been, infected previously. There were no neurovascular complications and no intraoperative femoral fractures. The femoral bone stock improved radiologically in 45 hips of which 29 showed considerable reformation of the proximal femur; 27 remained unchanged and two showed increasing osteoporosis.     

Revision total hip arthroplasty with a custom cementless stem with distal cross-locking screws. Early results in femora with large proximal segmental deficiencies

BACKGROUND: Revision total hip arthroplasty in the setting of a large proximal segmental femoral deficiency and/or discontinuity between the proximal and distal parts of the femur remains a challenging problem. We describe the use of a cementless stem with distal cross-locking screws to provide stability of the femoral implant in this situation. METHODS: Seventeen custom fully porous and hydroxyapatite-coated titanium femoral stems with distal cross-locking titanium screws were implanted in sixteen patients during revision total hip arthroplasty. Preoperatively, all of the patients had Paprosky grade-IIIB or IV femoral deficiencies. At the time of follow-up, the Harris hip scores were calculated and radiographs were made. A successful result was defined as a postoperative increase in the Harris hip score of >20 points, a radiographically stable implant, and no additional femoral reconstruction. RESULTS: At the time of final follow-up, at a mean of 5.3 years postoperatively, the result was successful in sixteen of the seventeen hips, the mean Harris hip score had improved from 35 to 76 points, and all implants were clinically and radiographically stable. There were no postoperative infections or hip dislocations. CONCLUSIONS: The use of a custom femoral stem with distal cross-locking screws can provide at least intermediate-term clinical and radiographic stability in patients with Paprosky grade-IIIB or IV femoral deficiencies. Longer follow-up will be required to determine the longevity of these implants.     

Long-term results of total hip arthroplasty using Charnley Elite-Plus stem and the effect of stem geometry on radiographic distal femoral cortical hypertrophy

Background

The Elite-Plus stem has two shape variations: roundback and flanged. The correlation between the radiographic results and stem geometry has not been previously investigated. The objective of this study was to evaluate the long-term primary total hip arthroplasty results using Elite-Plus stems, and the effect of stem geometry on radiographic distal femoral cortical hypertrophy.

The effect of flexion alignment in total hip arthroplasty with a cementless tapered-wedge femoral stem

Introduction

The influence of stem sagittal alignment on clinical outcomes is unclear in total hip arthroplasty (THA). The purpose of this study is to assess the relationship between stem sagittal alignment and clinical and radiographic outcomes using 3D-CT.

Materials and methods

We performed 370 consecutive primary THAs between 2009 and 2013. After exclusion, 102 hips in 89 patients using single tapered-wedge stem were included. Mean follow-up was 4.7 years. Stem sagittal alignment was measured using CT, and patients were divided into flexion and neutral alignment groups. Clinical and radiographic outcomes were compared between two groups. Furthermore, we evaluated the anterior femoral offset and initial contact state.

Results

There were no significant differences in clinical or radiographic outcomes between two groups. CT data analysis and multiple regression analysis showed flexion alignment increased anterior femoral offset (AFO) and Gruen zone 4 contact area.

Conclusions

There was no significant difference in clinical or radiographic outcomes between flexion and neutral alignment of the tapered-wedge stem at an average of 4.7 years of follow-up. The increase of AFO and distal contact area in flexion alignment could affect the improvement of impingement-free range of flexion and intraoperative fracture.

     

Cortical strut allografts for the treatment of femoral fractures and deficiencies in revision total hip arthroplasty

Thirty-three hips had revision total hip arthroplasty, using an average of three cortical strut allografts fixed to the femur with cables and followed-up for a mean of 4 years. The indications for strut allografts were ectatic femurs or segmental defects of the femoral diaphysis (22 hips), femoral fractures (10 hips), and severe proximal femoral osteolysis (1 hip). Twenty-one hips had an excellent or good clinical result, 6 had a fair clinical result, and 6 had a poor clinical result. Reoperation was done in six hips, but in only two hips was reoperation related to failure of the allograft. Nine of the 10 femoral fractures repaired with allograft struts healed by 3 to 6 months. Radiographs showed partial or complete bridging of the allograft to host bone with peripheral remodeling and minimal resorption in 30 of 33 hips. Strut allografts, fixed with multiple cables, are an important adjunct to femoral component revision for the restoration of deficient femoral bone stock and in the treatment of periprosthetic femur fractures.     

Revision total hip replacement with a cemented long femoral component: minimum 9-year follow-up results

Background

Surgical revision after failed total hip replacement is a technically challenging procedure. The aim of this study was to analyze the long-term results of revision total hip replacement using a cemented long femoral component and identify factors that influence the results.

Methods

We retrospectively reviewed 34 hips in 33 patients who had undergone revision total hip replacement using a cemented long femoral component between 1994 and 2001. Hip function was evaluated according to the scoring system of the Japanese Orthopaedic Association. Radiographic examination was performed for evaluation of stem loosening, and its possible risk factors were investigated.

Results

The mean follow-up duration was 11.3 years (9–15). Perioperative complications included intraoperative femoral cortex perforation (six hips, 18 %), dislocation (five hips, 15 %), deep venous thrombosis (one hip, 3 %) and postoperative periprosthetic fracture (one hip, 3 %). The mean preoperative Japanese Orthopaedic Association hip score was 50.3 ± 14.9 vs 78.2 ± 11.5 at the latest follow-up. The Kaplan–Meier survival rate at 15 years, calculated using radiological failure or re-revision of the femoral component for any reason as the end point, was 87 or 100 %, respectively. The failure-free survival rate for the subgroup with a good-quality cement mantle was significantly higher than that for the subgroup with poor quality (p = 0.033).

Conclusions

The quality of cementation was identified as a significant risk factor for further loosening. Revision total hip replacement using a cemented long femoral component yielded satisfactory long-term results in this series.     

Treatment of distal femoral nonunion and delayed union by using a retrograde intramedullary interlocking nail

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How stiffness and distal interlocking of revision hip stems influence the femoral cortical strain pattern

Background

Stress shielding and nonphysiological load transfer after primary or revision total hip replacement (THR) prepare the ground for resorptive bone remodeling. The quality of the bone stock influences the risk of periprosthetic fractures and the severity of future revision surgeries. The question of whether or not bending stiffness and distal screw interlocking influence load transfer of a modular revision hip stem with a solid, hollow, and hollow-slotted stem extension led to the conception of this experimental study. The results were compared with a standard hip stem for primary THR.

Methods

Revision stems were implanted in photoelastically coated composite femora. Cortical strain mapping was conducted before and after insertion of the implants under standardized loading conditions, considering the relevant muscle forces. Statistical analysis was based on a 95% confidence interval and a variance analysis for repeated measurements.

Results

Significant stress shielding was observed after insertion of all types of hip stems compared with the intact femora. There was also a marked difference between strain alterations induced by standard and revision hip stems. With revision stems, the most distinct stress shielding effects were registered with the solid stem extension, particularly in the femoral diaphysis. Distal interlocking screws only had a local action on strain pattern and tended to enhance stress shielding at the midstem area when using the more flexible components.

Conclusion

More flexible revision stems provide a cortical strain pattern of the femur closer to the preoperative status. This may reduce resorptive bone remodeling in the long term. However, any type of revision stem tested in this study caused higher stress shielding than the hip stem for primary THR, especially in the diaphyseal region medially and laterally. With sufficient proximal anchorage, the influence of distal interlocking screws on the femoral strain pattern was localized.     

Revision total hip arthroplasty using a fluted and tapered modular distal fixation stem with and without extended trochanteric osteotomy

We reviewed 62 revision total hip arthroplasties performed using a fluted and tapered modular distal fixation stem after a mean follow-up of 4.2 years. An extended trochanteric osteotomy (ETO) was used in 32 of the 62 hips (52%), whereas no osteotomy was used in the remaining 30 hips. The mean postoperative Harris hip score among the patients was 87.3 points. The mean stem subsidence was 1.1 mm. With the exception of one reoperation for a deep infection, no femoral revision was performed because of mechanical failure. Complications included intraoperative diaphyseal split fractures (6%), cortical perforations (6%), and dislocations (5%). Postoperative Harris hip scores, femoral component stability, and overall complication rates did not differ between the group treated with an ETO and that treated without it. However, the rates of cortical perforation and marked stem subsidence (>5 mm) were significantly higher in the group treated without an ETO than those in the group treated with an ETO, but these were not significantly different when stratified by femoral bone defect. The potential advantages of this implant design could be highlighted in a clinical setting when inserted using an ETO.     

Periprosthetic fracture of the femur after hip arthroplasty: The clinical outcome using cortical strut allografts

Between 1993 and 1998, 15 patients with periprosthetic fractures of the femur after hip arthroplasty were treated using deep-frozen cortical strut allografts as an adjunct support after internal fixation or revision arthroplasty. According to the Vancouver classification system, there were 7 type B1, 2 type B2, 4 type B3 and 2 type C fractures. Seven patients had severe osteopenia, 10 patients had bone defects between 2 to 7 cm and 2 were associated with infection. Nine patients had internal fixation of the fracture using a compression plate, and 6 had revision arthroplasty using a long-stemmed femoral prosthesis. The average length of the allograft was 13.9 cm. At an average follow-up of 31 months, all the patients had a satisfactory functional result except one who had a leg length discrepancy of 4 cm due to multiple operations. There were no non-unions, malunions or infections. The fractures healed between 10 to 24 weeks (average, 15.6 weeks). In conclusion, a cortical strut allograft associated with internal fixation can be an effective method of treating periprosthetic fractures of the femur after hip arthroplasty.     

Bilateral femoral component breakage in total hip replacement: a case report

Breakage of the femoral component of a total hip replacement prosthesis is an uncommon occurrence with modern prostheses. The authors report what appears to be the only case of bilateral prosthetic fracture. A 65-year-old man, who was physically active, suffered bilateral femoral stem fractures 3 and 5 years after total hip replacement. The bilateral cemented hip replacements remained asymptomatic until catastrophic failure of the femoral component occurred. Both the prostheses were titanium (Biomet; Warsaw, Ind.) with chrome cobalt modular femoral heads. The authors stress the importance of maintaining an adequate cement mantle in Gruen zones 1 and 7 because failure to do so may result in micromotion and subsequent stem fracture.     

Treatment of femoral bony defects with a modular hip prosthesis and distal interlocking

Patients with bony defects of the proximal femur after trochanteric fracture, implant failure (cut-out), periprosthetic fracture or aseptic loosening of prosthesis are difficult to treat with primary or revision endoprosthesis. Modular femoral hip prosthesis (MHP) with stems of different length and the possibility of distal interlocking screws are an operative solution for those patients. In a prospective study from January 1996 to January 2002 all patients treated with a MHP because of proximal and / or distal femoral bony defect or fracture were included. Follow-up after 6 to 30 months was evaluated clinically and radiologically in hospital. Change of modified Harris Hip Score and radiological signs of loosening (radiolucent line, migration of MHP, breaking interlocking screw) were documented. 106 patients with a follow-up of 58.5 % were included in the study. At time of follow-up clinical and radiological outcome after trochanteric fracture was good. Harris Hip Score was comparable to the situation of patients before fracture, only one MHP was loose. However in patients after revision arthroplasty 25 % of MHP were loose and in many patients the interlocking screw was broken. Distal interlocking screw in MHP prevents stability after trochanteric fracture to achieve osseointegration. However in case of periprosthetic fracture or revision arthroplasty MHP shows insufficient stability in many cases.     

股骨交锁髓内钉远端锁钉体外透视定位器的研制及临床应用

[目的]研制股骨交锁髓内钉远端锁钉体外透视定位器,探讨其在治疗股骨干骨折手术中远端锁钉的疗效。[方法]2012年10月~2016年1月收治的股骨干骨折行交锁髓内钉手术内固定患者220例,在进行远端锁钉操作时发生锁钉失败64例,随机分为调节定位器组和徒手组。调节定位器组(33例)用自制定位器进行远端锁钉,徒手组(31例)采用透视下徒手髓内钉远端瞄准方法。所有患者术后随访13~18个月,平均15.1个月。比较两组手术中的远端锁钉时间、锁钉成功率、透视时间、术中出血量。[结果]调节定位器组与徒手组相比较,在远端锁钉时间[(4.61±1.71)mins vs(17.06±2.57)min,P0.05],锁钉成功率(100%vs 89%,P0.05),透视时间[(2.06±1.22)min vs(12.87±2.85)min,P0.05],术中出血量[(210.27±13.94)ml vs(381.00±27.75)ml,P0.05],两组间差异均具有统计学意义。[结论]该定位器与原有机械定位系统匹配良好,是常规机械远端锁钉失败时有效的替代定位器。