High Incidence of Irradiated Cortical Strut Allograft Resorption Following Revision of Femoral Stems

BackgroundDespite the widespread use of revision total hip arthroplasties using cementless stems and cortical strut allografts, graft resorption has not been explicitly studied.MethodsBetween 2010 and 2018, 40 femoral strut grafts were used in the revision of femoral stems of 36 patients (18 males and 18 females; average age, 51.9 ± 12.9 years). The mean follow-up was 78.9 ± 37.3 months. Failure was defined as revision surgery for any reason and subsidence of greater than 5 mm.ResultsThe survival rate of the stem without the need for revision at 5 years was 95% (mean graft survival time, 10.8 [95% CI, 9.414-12.234] years). Overall survival with graft resorption as the endpoint was 90% at 5 years (mean graft survival time, 8.8 [95% CI, 7.5-10.2] years). Survival with graft nonunion as the endpoint was 90% at 3 years (mean survival time, 11.7 [95% CI, 10.5-12.8] years).ConclusionThe resorption rate increases proportionally to the follow-up duration and can be very severe in a high percentage of cases. Long-term multicenter studies are required to assess the effect of resorption on prosthesis longevity.     

Freeze Dried Proximal Femoral Allografts in Revision of Femoral Stems

Background

Femoral bone deficiency is a challenging problem in revision femoral arthroplasty in younger patients. We evaluated outcomes of revision femoral arthroplasty using a freeze-dried allograft prosthetic composite (APC).

A Role for Modern Primary Cementless Femoral Stems in Revision Hip Arthroplasty

BackgroundIn revision total hip arthroplasty (THA) cases with preserved femoral metaphyseal bone, tapered proximally porous-coated “primary” femoral stems may be an option. The objective of this study was to compare outcomes of patients with Paprosky I or II femoral bone loss undergoing revision THA with either a primary metaphyseal-engaging cementless stem or a revision diaphyseal-engaging stem.MethodsThis was a retrospective analysis of 70 patients with Paprosky I or II femoral bone loss who underwent femoral revision. 35 patients who were revised using a primary cementless femoral stem were compared with 35 patients who underwent femoral revision using a revision diaphyseal-engaging stem. The groups were similar regarding age, gender, body mass index, and American Society of Anesthesiologists. Clinical and radiographic outcomes and complications were compared over an average follow-up of 2.9 years (SD 1.4).ResultsRevision THA was most commonly performed for periprosthetic joint infection (N = 27, 38.6%). The groups were similar with regards to Paprosky femoral classification (P = .56), length of stay (P = .68), discharge disposition (P = .461), operative time (P = .20), and complications (P = .164). There were no significant differences between primary and revision femoral stem subsidence (0.12 vs. 0.75 mm, P = .18), leg length discrepancy (2.3 vs. 4.05 mm, P = .37), and Hip Disability and Osteoarthritis Outcome Score Jr (73.1 [SD 21.1] vs. 62.8 [SD 21.7], P = .088). No patient underwent additional revision surgery involving the femoral component.ConclusionUse of modern primary cementless femoral stems is a viable option for revision hip arthroplasty in the setting of preserved proximal femoral metaphyseal bone. Outcomes are not inferior to those of revision stems and offer potential benefits.     

High Survivorship of Short-Cemented Femoral Stems in Condylar Revision Total Knee Arthroplasty Without Significant Metaphyseal Bone Loss: Minimum 5-Year Follow-Up

BackgroundWe aimed to evaluate the outcomes of hybrid fixation technique in condylar revision total knee arthroplasty (rTKA) using cementless metaphyseal tibial sleeves and short-cemented femoral stems with a rotating platform articulation.MethodsRetrospective consecutive study of all condylar rTKAs with a cemented femoral stem between 2009 and 2016 was conducted. Patients were identified using a local prospective database and linkable data obtained from the National Joint Registry for rTKA. Demographic, clinical, and surgical data were collected from patients’ electronic health records. The primary outcome measure was mechanical failure and implant survivorship using a nationally collected data, complications, re-operations, and “any-cause revision” were also recorded.ResultsThere were 72 consecutive patients (72 knees) with minimum 5-year follow-up: 33 (45.8%) females and 39 (54.2%) males with a median age of 70 years (range 47-88). The indication for revision surgery was aseptic loosening (n = 34, 47.2%), instability (n = 17, 23.6%), infection (n = 14, 19.5%) with 10 patients having 2-stage approach and 4 patients with single-stage approach, stiffness (n = 4, 5.6%), and malalignment (n = 3, 4.1%). At mean follow-up of 6.87 years (median 6.7; range 5-11.8), only 2 patients required revision for infection. Using “any-cause implant revision” as an end point, implant survivorship for this construct was 97.2% at median 6.7 years. To date, none of the femoral stems have been revised for mechanical failure.ConclusionIn rTKA with good femoral condylar bone stock, we have shown excellent survivorship with a short-cemented femoral stem, in conjunction with a mobile-bearing and a tibial sleeve. This has the advantage of reducing the length of the revision construct of this complex surgery.Level of EvidenceLevel IV.     

Satisfying Outcomes Scores and Survivorship Achieved With Impaction Grafting for Revision THA in Young Patients

Background

The increasing number of total hip arthroplasties (THAs) performed in younger patients will inevitably generate larger numbers of revision procedures for this specific group of patients. Unfortunately, no satisfying revision method with acceptable survivorship 10 years after revision has been described for these patients so far.

Questions/purposes

The purposes of this study were to (1) analyze the clinical outcome; (2) complication rate; (3) survivorship; and (4) radiographic outcome of cemented revision THA performed with impaction bone grafting (IBG) on both the acetabular and femoral sides in one surgery in patients younger than 55 years old.

Methods

During the period 1991 to 2007, 86 complete THA revisions were performed at our institution in patients younger than 55 years. In 34 of these 86 revisions (40%), IBG was used on both the acetabular and femoral sides in 33 patients. Mean patient age at revision surgery was 46.4 years (SD 7.6). No patient was lost to followup, but three patients died during followup. None of the deaths were related to the revision surgery. The mean followup for the surviving hips was 11.7 years (SD 4.6). We also analyzed complication rate.

Results

The mean Harris hip score improved from 55 (SD 18) preoperatively to 80 points (SD 16) at latest followup (p = 0.009). Six hips underwent a rerevision (18%): in four patients, both components were rerevised; and in two hips, only the cup was revised. Patient 10-year survival rate with the endpoint of rerevision for any component for any reason was 87% (95% confidence interval [CI], 67%–95%) and with the endpoint of rerevision for aseptic loosening, the survival rate was 97% (95% CI, 80%–100%). In total six cups were considered radiographically loose, of which four were rerevised. Three stems were radiographically loose, of which none was rerevised.

Conclusions

IBG is a valuable biological revision technique that may restore bone stock in younger patients. Bone stock reconstruction is important, because these patients likely will outlive their revision implants. Bone reconstruction with impaction grafting may facilitate future revisions.

Level of Evidence

Level IV, therapeutic study.     

Cementless Metaphyseal Sleeves Used for Large Tibial Defects in Revision Total Knee Arthroplasty

Revision arthroplasty of large tibial defects remains a challenge. Thirty revision knee arthroplasties using a porous titanium tibial sleeve for Anderson Orthopaedic Research Institute (AORI) Type 2B and Type 3 defects with minimum 2 year follow up were retrospectively reviewed. The average Knee Society Score increased from 55 pre-operatively to 92 post-operatively. Six patients had a repeat operation though none were sleeve related. All radiographs at final follow-up showed well fixed components with osseous in-growth. Seven patients had end-of-stem pain, four of which resolved. Our short-term results show that porous titanium sleeves are a promising option when managing large areas of metaphyseal bone loss by filling defects and providing stable construct with biologic fixation.     

Total Knee Arthroplasty With Fully Porous-Coated Stems For The Treatment of Large Bone Defects

Between February1999 and April 2006, 25 patients (28 knees) underwent a TKA by a single surgeon. At an average final follow-up of 7 ± 2 years (range, 3–10 years), 34 (100%) of 34 fully porous stems had achieved bone ingrowth. However, one case (3%) had a component loosening due to the de-bonding of sheets of beads from the stem. The remaining cases remained well fixed. Three well-fixed stems in 2 patients failed from deep infection. There was one reoperation required for a femoral periprosthetic fracture. Our 10-year experience shows that fully porous-coated stems reliably achieve durable fixation in complex primary and revision TKA allowing the surgeon to bypass large bone defects and gain fixation in diaphyseal bone.     

Revision Total Hip Arthroplasty for Large Medial Defects With Witch's Hat-Shaped Structural Allografts — Minimum 10-Year Follow-Up

A witch's hat-shaped structural allograft can restore bone stock over acetabular medial wall during revision total hip arthroplasty, which may be of importance for future re-revisions. However, long-term results are unclear. A retrospective review of 104 consecutive hips in 96 patients was performed to determine survivorship and functions. The minimum follow-up was 10 years. Nine patients required re-revision for cup aseptic loosening with a mean time to revision of 4.5 years. Kaplan–Meier survivorship was 89.4% at the endpoint. Radiographic evaluation revealed sixteen instances of minor medial wall graft absorption without significant cup migration. The mean modified Harris Hip Scores were 36 preoperatively and 86 at last follow-up. Revision acetabular surgery using a witch's hat-shaped allograft to restore acetabular medial wall provides an excellent alternative.     

Comparative Biomechanical In Vitro Study of Different Modular Total Knee Arthroplasty Revision Stems With Bone Defects

BackgroundThe aim of this study is to investigate the effects of different stem lengths and types including cones on primary stability in revision total knee arthroplasty with different femoral bone defects and fixation methods in order to maximize bone preservation. It is hypothesized that longer stems provide little additional mechanical stability.MethodsThirty-five human femurs were investigated. A distal bone defect, Anderson Orthopedic Research Institute classification (s. 33) type-F2a, was created in group 1-3 and type-F3 in group 4-6. A cemented, rotating hinge femoral component was combined with different stems (100 and 160 mm total or hybrid cemented cones, or a 100-mm custom-made anatomical cone stem). The femora were loaded according to in vivo loading during gait. Relative movements were measured to investigate primary stability. Pull-out testing was used to obtain a parameter for the primary stability of the construct.ResultsRelative movements were small and similar in all groups (<40 μm). For small defect, the pull-out forces of cemented long (4583 N) and short stems (4650 N) were similar and about twice as high as those of uncemented stems (2221 N). For large defects, short cemented stems with cones showed the highest pull-out forces (5500 N). Long uncemented stems (3324 N) and anatomical cone stems (3990 N) showed similar pull-out forces.ConclusionAll tested stems showed small relative movements. Long cemented stems show no advantages to short cemented stems in small bone defects. The use of cones or an anatomical cone stem with hybrid cementation seems to offer good stability even for larger bone defects. The use of a short cemented stem (with or without cone) may be a suitable choice with a high potential for bone preservation in total knee arthroplasty revision with respective bone defects.     

High Long-term Survival of Bulk Femoral Head Autograft for Acetabular Reconstruction in Cementless THA for Developmental Hip Dysplasia

Background  

Deficient acetabula associated with acetabular dysplasia cause difficulty achieving adequate coverage of the acetabular component during THA. Autografting with the removed femoral head has been used for several decades to achieve better coverage, but the long-term benefits of this technique remain controversial, with some series reporting high rates of graft resorption and collapse.     

Survivorship and Radiographic Evaluation of Metaphyseal Cones With Short Cemented Stems in Revision Total Knee Arthroplasty

BackgroundThe purpose of this study is to evaluate the survivorship and radiographic outcomes of a single design of metaphyseal cone used in conjunction with short cemented stems.MethodsA retrospective analysis was conducted of revision total knee arthroplasty (rTKA) patients (June 2015 to December 2017) using porous titanium femoral or tibial cones in conjunction with short cemented stems (50-75 mm). Minimum follow-up was 2 years. Survivorship, complications, and a modified Knee Society Radiographic score were analyzed.ResultsForty-nine rTKAs were included in the study (12 femoral cones, 48 tibial cones). Varus-valgus constraint was used in 28 (57%) and a hinged bearing was used in 3 (6%) of these constructs. The majority were index rTKAs of primary components (86%), performed for aseptic loosening (51%) and reimplantation following staged treatment for infection (37%). Median follow-up was 39 months (range 25-58). Using a modified Knee Society Radiographic score, all constructs were classified as stable. Postoperatively, 4 rTKAs were complicated by recurrent infection (8%), periprosthetic fracture 2 (4%), and superficial wound infection 1 (2%). Seven rTKAs (14%) required reoperation. The majority of reoperations (4 rTKAs) were debridement and irrigation with implant retention for infection. Metaphyseal cone constructs with short cemented stems demonstrated 100% survivorship free of revision for aseptic loosening without evidence of radiographic loosening in any case.ConclusionOur results demonstrate excellent outcomes with the use of metaphyseal cones with short cemented stems at mid-term follow-up. This construct avoids the use of long-stem fixation with the associated extraction difficulty, end of stem pain, and potential for malposition at the joint line.Level of EvidenceIV, Case Series.     

Revision With Impacted Bone Allografts and the Kerboull Cross Plate for Massive Bone Defect of the Acetabulum

We retrospectively reviewed 31 hips with massive bone defect because of aseptic loosening of the acetabulum treated with impacted bone allografts with the Kerboull-type acetabular device. Mean age at surgery was 67.9 years, and mean duration of follow-up was 6.3 years. Thickness of the bone graft was evaluated by postoperative radiography. Seven hips showed radiological failure associated with 6 breakages of the device, and 24 hips showed stability on follow-up radiographs. Of the 13 hips showing a bone graft thickness of greater than 20 mm on follow-up radiographs, 7 were classified as failure group. If an acetabular reinforcement device with a bone graft of more than 20 mm thickness is necessary, then a structural allograft should be considered in the weight-bearing area of the support ring in addition to the morselized bone graft.     

A New Classification System for Cementless Femoral Stems in Total Hip Arthroplasty

BackgroundThe growing variety of total hip arthroplasty implants necessitates a standardized, simple, and brand-neutral language to precisely classify femoral components. Although previous classifications have been useful, they need updating to include stems that have current surface treatment technologies, modularity, collar features, and other geometric characteristics.MethodsTo accomplish this, we propose a new classification system for stems based on 3 distinguishing stem features: (1) geometry, (2) location of modularity, and (3) length.ResultsOur system allows for the easy classification of all currently used stem types.ConclusionsOne goal of this endeavor is to improve clinical record keeping to facilitate study comparisons as well as literature reviews.     

Custom Cementless THA in Patients with Skeletal Dysplasia Results in Lower Apparent Revision Rates than Other Types of Femoral Fixation

Background  

Patients with skeletal dysplasia are prone to degenerative hip disease thus requiring THA at a younger age than the general population. This is a technically demanding procedure with high complication and revision rates. Achieving good femoral fixation can be challenging because of the abnormal features of the hip.     

Anterior Distal Femoral Osteotomy for Removal of Long Femoral Stems in Revision Knee Arthroplasty

Osteotomies of the proximal femur and proximal tibia in revision arthroplasty are well described while guidelines for distal femoral osteotomy are limited. Femoral stems are used with increasing frequency for fixation of revision components in knee arthroplasty and their removal is technically challenging particularly in the setting of infection. We describe a technique of anterior distal femoral osteotomy for revision knee arthroplasty to assist with removal of well-fixed long stemmed cemented or porous femoral components, as well as debridement of infection while preserving bone stock and soft tissue attachments.