Aims

There are limited long-term studies reporting on outcomes of the Zimmer Modular Revision (ZMR) stem, and concerns remain regarding failure. Our primary aim was to determine long-term survival free from all-cause revision and stem-related failure for this modular revision stem in revision total hip arthroplasty (THA). Secondary aims included evaluating radiological and functional outcomes.

Aims

United Classification System (UCS) B2 and B3 periprosthetic fractures in total hip arthroplasties (THAs) have been commonly managed with modular tapered stems. No study has evaluated the use of monoblock fluted tapered titanium stems for this indication. This study aimed to evaluate the effects of a monoblock stems on implant survivorship, postoperative outcomes, radiological outcomes, and osseointegration following treatment of THA UCS B2 and B3 periprosthetic fractures.

Aims

Large acetabular bone defects encountered in revision total hip arthroplasty (THA) are challenging to restore. Metal constructs for structural support are combined with bone graft materials for restoration. Autograft is restricted due to limited volume, and allogenic grafts have downsides including cost, availability, and operative processing. Bone graft substitutes (BGS) are an attractive alternative if they can demonstrate positive remodelling. One potential product is a biphasic injectable mixture (Cerament) that combines a fast-resorbing material (calcium sulphate) with the highly osteoconductive material hydroxyapatite. This study reviews the application of this biomaterial in large acetabular defects.

Aims

With increasing burden of revision hip arthroplasty (THA), one of the major challenges is the management of proximal femoral bone loss associated with previous multiple surgeries. Proximal femoral arthroplasty (PFA) has already been popularized for tumour surgeries. Our aim was to describe the outcome of using PFA in these demanding non-neoplastic cases.

Aims

Femoral cement-in-cement revision is a well described technique to reduce morbidity and complications in hip revision surgery. Traditional techniques for septic revision of hip arthroplasty necessitate removal of all bone cement from the femur. In our two centres, we have been using a cement-in-cement technique, leaving the distal femoral bone cement in selected patients for septic hip revision surgery, both for single and the first of two-stage revision procedures. A prerequisite for adoption of this technique is that the surgeon considers the cement mantle to be intimately fixed to bone without an intervening membrane between cement and host bone. We aim to report our experience for this technique.

Aims

One-stage revision hip arthroplasty for periprosthetic joint infection (PJI) has several advantages; however, resection of the proximal femur might be necessary to achieve higher success rates. We investigated the risk factors for resection and re-revisions, and assessed complications and subsequent re-revisions.

Aims

Although good clinical outcomes have been reported for monolithic tapered, fluted, titanium stems (TFTS), early results showed high rates of subsidence. Advances in stem design may mitigate these concerns. This study reports on the use of a current monolithic TFTS for a variety of indications.

Introduction. The number of medial unicompartmental knee replacements (UKR) performed for arthritis has increased and as such, revisions to total knee replacement (TKR) is increasing. Previous studies have investigated survivorship of UKR to TKR revision and functional outcomes compared to TKR to TKR revision, but have failed to detail the surgical considerations involved in these revisions. Our objectives are to investigate the detailed surgical considerations involved in UKR to TKR revisions. Methods. This study is a retrospective comparative analysis of a prospectively collected database. From 2005 to 2017, 61 revisions of UKR to TKR were completed at a single center. Our inclusion criteria included: revision of UKR to TKR or TKR to TKR with minimum 1 year follow-up. Our exclusion criteria include: single component and liner revisions and revision for infection. The 61 UKR to TKR revisions were matched 2:1 with respect to age, ASA and BMI to a group of 122 TKR to TKR revisions. The following data was collected: indication for and time to revision, operative skin to skin surgical time, the use of specialized equipment (augment size/location, stem use), intraoperative and postoperative complications, re-operations and outcome scores (WOMAC, Oxford 12, SF 12, satisfaction score). Results. There were no statistical differences between the demographic data from either group (age, BMI, ASA, sex and follow-up range). Progression of arthritis was the most common reason for revision in the UKR to TKR group (30/61, 49%, p < 0.001). Aseptic loosening was the most common reason for revision in the TKR to TKR group (73/122, 60%,) and was encountered more often than aseptic loosening in the UKR to TKR group (21/61, 35%, p=0.002). The operative time was longer in the TKR to TKR group (77 vs 112 min, p< 0.001). Femoral augmentation was required for one 1/61 (1.64%) UNI and 92/122 (75%) TKR revisions, respectively (p <0.001). Medial tibial augments were required in 9/61 (14.8%) of the UKR to TKR group while 12/122 (10%) and 10/122 (8%) of the TKR to TKR group required medial and full tibial augments, respectively (p=0.7). UKR to TKR revisions never required femoral stems while 120/122 (98%) of the TKR to TKR group did (p<0.001). Tibial stems were required in 19/61 (31%) and 122/122 (100%) of UKR to TKR and TKR to TKR groups, respectively (p<0.001). There was no statistical difference in the overall complication rate of either group (15% in the UKR to TKR group and 13% in the TKR to TKR group, p = 0.9). Stiffness was a common complication of UKR to TKR and TKR to TKR re-revisions at 2/61 (3%), and 6/122 (5%), respectively (P = 0.6). Aseptic loosening was also a common complication of in both groups at 2/61 (3%) and 4/122 (3%) in the UKR to TKR and TKR to TKR groups, respectively (p = 0.7). There was no statistical difference in the re-operation rate of either group (10% in the UKR to TKR group and 7% in the TKR to TKR group, P = 1). Stiffness was the most common indication for re-operation in the UKR to TKR group (2/61, 3%, p = 0.11) while aseptic loosening was the most common in the TKR to TKR group (4/122, 3.2%, p = 0.7). The survivorship in the UKR to TKR was 93% and 90% at 5 and 9 years, respectively. The survivorship in the TKR to TKR group was 95% and 94% at 5 and 9 years, respectively, which was not statistically different from the UKR group. Discussion. The most common reason for revision was different between the two groups (p < 0.001) while the skin to skin time was longer in the TKR to TKR group. In terms of revision components, femoral stems were never required in the UKR to TKR group while tibial stems were only required in 31%. Similarly, medial tibial augments were only required in 15% of the UKR to TKR group. While the surgeon must be prepared to use augmentation and stems in UKR to TKR revisions, they can often be completed with primary components and therefor will have an overall lower cost to the health care system. Furthermore, the survivorship and re-operation between the two groups was similar which supports previous literature. The results of this study will allow for a more in-depth cost-effectiveness analysis of UKR to TKR vs TKR to TKR in arthroplasty decision making. Unicompartmental knee replacements should be considered in appropriate patients to decrease the lifetime cost of arthroplasty intervention and potentially decrease the burden on the health care system. For figures, tables, or references, please contact authors directly

The well-fixed femoral stem can be challenging to remove. Removal of an extensively osteointegrated cementless stem requires disruption of the entire implant-bone interface while a well-fixed cemented stem requires complete removal of all adherent cement from the underlying cortical bone in both the metaphysis and diaphysis of the femur. In these situations, access to those areas of the femur distal to the metaphyseal flare that are beyond the reach of osteotomes and high speed burrs is necessary. This typically requires use of an extended femoral osteotomy (ETO). The ETO should be carefully planned so that it extends distal enough to allow for access to the end of the stem or cement column and still allow for stable fixation of a new implant. Too short of an ETO increases the risk of femoral perforation by straight burrs, trephines or cement removal instruments that cannot negotiate the bowed femoral canal to access the end of the cement column or end of the stem without risk of perforation. The ETO should also be long enough to allow for fixation with at least 2 cerclage cables. An ETO that is too distal makes implant and cement removal easier, but may not allow for sufficient fixation of a new revision femoral stem. After insertion of the revision stem, the osteotomy is reduced back around the stem and secured in place with cerclage cables

Aim. Infection rates after revision THA vary widely, up to 12%. In countries that use antibiotic-loaded cemented stems in combination with perioperative IV antibiotics, infection rates in registry studies are lower. In many countries, however, cementless revision implants are preferred. Our aim was to apply an antibiotic-loaded calcium sulfate coating to cementless revision stems to reduce periprosthetic joint infection (PJI). This study sought to answer two questions: 1) Does the coating of cementless revision stems with calcium sulfate inhibit osteointegration in THA? 2) Does the antibiotic-loaded calcium sulfate coating of revision stems reduce the incidence of PJI?. Method. From Dec. 2010 to Dec. 2015, 111 consecutive revision femoral stems were coated with commercially pure calcium sulfate. 10cc of calcium sulfate was mixed with 1g of vancomycin powder and 240mg of tobramycin liquid and applied to the stem in a semi-firm liquid state immediately prior to stem insertion. The results are compared to a designated control cohort (N=104) performed across the previous 5 years. The surgical methods were comparable, but for the stem coating. All patients were staged preoperatively using the Musculoskeletal Infection Society Staging System and followed for at least 1 year. Results. In the study group of coated stems, there were 46 A hosts, 56 B hosts, and 9 C hosts. In the control group, there were 45 A hosts, 52 B hosts, and 7 C hosts. Both cohorts had 0 cases of aseptic loosening. The overall rate of PJI in the study cohort was 2.7%. Of the 111 revisions, 69 were aseptic (PJI=1.4%) and 42 were second stage revisions for infection (PJI=4.8%). PJI occurred in 2.2% of A hosts, 1.8% of B hosts, and 11.1% of C hosts. In the control cohort, the overall rate of PJI was 7.7%. Of the 104 revisions, 74 were aseptic (PJI=1.4%) and 30 were second stage revisions for infection (PJI=23.3%). PJI occurred in 6.7% of A hosts, 5.8% of B hosts, and 28.6% of C hosts. The results show a reduction in PJI from 7.7% in the control group to 2.7% in the study group and were found to be statistically significant at p-value<0.1 (p=0.09). Conclusions. The application of antibiotic-loaded calcium sulfate to cementless revision femoral stems does reduce PJI. Importantly, this coating did not inhibit osteointegration of the femoral stem. The reduced infection rate in this study supports the concept that bacteria frequently contaminate and reside within the femoral canal

Aims

Femoral stems with exchangeable (modular) necks were introduced to offer surgeons an increased choice when determining the version, offset and length of the femoral neck during total hip arthroplasty (THA). It was hoped that this would improve outcomes and reduce complications, particularly dislocation. In 2010, the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) first reported an increased rate of revision after primary THA using femoral stems with an exchangeable neck. The aim of this study was to provide a more comprehensive up-to-date analysis of primary THA using femoral stems with exchangeable and fixed necks.

Aims

The aim of this study was to investigate the outcomes of Vancouver type B2 and B3 fractures by performing a systematic review of the methods of surgical treatment which have been reported.

The well-fixed cemented femoral stem and surrounding cement can be challenging to remove. Success requires evaluation of the quality of the cement mantle (interface lucency), position of the stem, extent of cement below the tip of the stem and skill with the specialised instruments and techniques needed to remove the stem and cement without perforating the femur. Smooth surfaced stems can usually be easily removed from the surrounding cement mantle with a variety of stem extractors that attach to the trunnion or an extraction hole on the implant. Roughened stems can be freed from the surrounding cement mantle with osteotomes or a narrow high speed burr and then extracted with the above instruments. Following this, the well-fixed cement mantle needs to be removed. Adequate exposure and visualization of the cement column is essential to remove the well-fixed cement without damage to the bone in the femur. This is important since fixation of a revision femoral component typically requires at least 4 cm of contact with supportive cortical bone, which can be difficult to obtain if the femur is perforated or if the isthmus damaged. Proximally, cement in the metaphyseal region can be thinned with a high speed burr, then split radially and removed piecemeal. It is essential to remember that both osteotomes and high speed burrs will cut thru bone easier than cement and use of these instruments poses a substantial risk of unintended bone removal and perforation of the femur if done improperly. These instruments should, as a result, be used under direct vision. Removal of more distal cement in the femur typically requires use of an extended femoral osteotomy (ETO) to allow for adequate access to the well-fixed cement in the bowed femoral canal. An ETO also facilitates more efficient removal of cement in the proximal femur. The ETO should be carefully planned so that it is distal enough to allow for access to the end of the cement column and still allow for stable fixation of a new implant. Too short of an ETO increases the risk of femoral perforation since the straight cement removal instruments cannot negotiate the bowed femoral canal to access the end of the cement column without risk of perforation. An ETO that is too distal makes cement removal easier, but may not allow for sufficient fixation of a new revision femoral stem. Cement below the level of the ETO cannot be directly visualised and specialised instruments are necessary to safely remove this distal cement. Radiofrequency cement removal devices use high frequency (ultrasonic) radio waves to melt the cement within the canal. Although cement removal with these devices is time consuming and tedious, they do substantially reduce the chances of femoral perforation. These devices can, however, generate considerable heat locally and can result in thermal injury to the bone and surrounding tissues. Once the distal end of the cement mantle is penetrated, backbiting or hooked curettes can be use to remove any remaining cement from within the canal. It is important that all cement be removed from the femur since reamers used for preparation of the distal canal will be deflected by any retained cement, which could result in eccentric reaming and inadvertent perforation of the femur and make fixation of a new implant very challenging. An intra-operative x-ray can be very helpful to insure that all cement has been removed before reaming is initiated. One should always plan for a possible femoral perforation and have cortical strut grafts and a stem available that will safely bypass the end of the cement column and the previous cement restrictor

It's easy to say that hip resurfacing is a failed technology. Journals and lay press are replete with negative reports concerning metal-on-metal bearing failures, destructive pseudotumors, withdrawals and recalls. Reviews of national joint registries show revision risks with hip resurfacing exceeding those of traditional total hip replacement, and metal bearings fare worst among all bearing couples. Yet, that misses the point. Modern hip resurfacing was never meant to replace total hip replacement (THR). It was intended to preserve bone in young patients who would be expected to need multiple revisions due to their youth and high-demand activities. The stated goal of the developers of the Birmingham Hip Resurfacing (BHR) was to delay THR by 10 years. In the two decades that followed the release of BHR, this goal has been met and exceeded. Much has been learned about indications, patient selection, and surgical technique. We now know that this highly specialised, challenging procedure is best indicated in the young, active male with osteoarthritis, as a complementary, not competitive procedure, to THR. Resurfacing has many advantages. First and foremost, it saves bone, on the day of surgery, and over the next several years by preventing stress shielding. Dislocations are very rare. Leg length discrepancy and changes in offset are avoided. Post-operative activity, including heavy manual labor and contact sports, is unrestricted. More normal loading of the femur and joint stability has allowed professional athletes to regain their careers. Femoral side revisions, if necessary, are simple total hips, and dual mobility constructs allow one to keep the socket. Adverse reactions to metal debris (ARMD), including pseudotumors, have generated great concern. Initially described only in women, it was unclear whether the etiology was allergy, toxicity, or inflammation. A better understanding of the wear properties of the bearing, and its relation to size, anteversion, hip dysplasia and metallurgy, along with retrieval analysis, allow us to conclude that it is excessive wear due to edge loading which is the fundamental mechanism for the vast majority of ARMD. Thus, patient selection, implant selection and surgical technique, the orthopaedic triad, are paramount. What has been most impressive are the truly exceptional results in young, active men. The worst candidates for THR turn out to be the best candidates for resurfacing. The ability to return to full, unrestricted activity is just as important to these patients as the spectacular survivorship in centers specializing in resurfacing. If they are unlucky and face a revision, they are not facing the life-changing outcomes of a long revision femoral stem. So if the best indication for hip resurfacing is the young, active male, let's look at the results of resurfacing these patients in centers with high volumes, using devices with a good track record, such as BHR. Several centers around the world report 10–18 year success rates of BHR in males under 50 at 98–100%. Return to athletics is routinely achieved, and even professional athletes have regained their careers. Hip resurfacing doesn't have to be better than THR to be popular among patients. Just the idea of saving all that bone makes it attractive. In the young active male, however, the results exceed those of THR, while leaving better revision options for the future. This justifies its continued use in this challenging patient population

Introduction. The risk of hip dislocation after revision total hip arthroplasty is up to 20% following surgery for periprosthetic fractures. A technique was developed by the senior authors, involving a transtrochanteric osteotomy and superior capsulotomy to attempt to minimise this risk(1). Methods. This prospective study examines a cohort of 40 patients undergoing this novel technique, which involves extending the fracture proximally to the tip of the greater trochanter. This is then extended into the soft tissues in the mid lateral plane as a split of the glutei and a minimally superior capsulotomy (preserving the anterior and posterior capsule). This allows for revision of the femoral component, and retention of the socket and liner. The outcomes of interest to the authors were dislocation rates, clinical outcome measured using the Oxford hip score. These were assessed along with X-ray imaging at 1, 2 and 5-year intervals to confirm fracture union and measure stem subsidence. Results. Patients averaged 80 years of age, with a higher ratio of females (3:2). There were no cases of hip joint dislocations. Two patients (5%) underwent subsequent revision hip arthroplasty within the first 12 months of initial revision. Femoral stem subsidence at 1 year averaged 5.9 mm. All fractures showed radiological evidence of union. The Oxford hip score was fair, averaging 31/48 by 1 year post-op, and then plateaued at 32.8/48 at 2 years post-op. Conclusion. 5 year follow-up of this novel operative technique in revision arthroplasty of Vancouver B periprosthetic hip fractures has confirmed the benefits, with no cases of hip dislocation, along with overall satisfactory patient clinical outcomes

Modularity in femoral revision stems was developed to reduce subsidence, leg length discrepancy and dislocation experienced in revision surgery. The Wagner SL Revision Stem (Zimmer, Warsaw, IN) has been known for excellent bony fixation and proximal bony regeneration, but the third-generation proportional neck offset and 135° neck-shaft angle has an unknown track record. Our aim is to study the effect of these design modifications on stem subsidence, dislocation rate and stem survival. We reviewed 76 consecutive femoral revisions (70 patients; 50 M: 20 W; 67.7 yo [range; 37.7 – 86.6 yo]) with the Wagner SL implanted at our institution (2004–2012). No patient was lost to follow-up, but nine had died, and one patient was excluded for a Paprosky type I femoral bone defect. This leaves us 66 hips (60 patients) at 2 to 9.5 years of follow-up (mean 55 months; range, 24–114 months). Indications for revisions included aseptic stem loosening (62.1%), infection (13.6%), acetabular loosening (12.1%), recurrent dislocation (4.5%), periprosthetic (4.5%) and stem fracture (1.5%), and chondrolysis (1.5%). Patients were actively followed up at regular intervals to ascertain revision status and outcome measures including the Merle d'Aubigné (n=53), WOMAC questionnaires (n=59) and radiographs (n=66). Radiographs were evaluated for stem subsidence (mm). One of the surviving 66 stems was revised for recurrent deep infection (1.5%). No patient underwent revision of the femoral stem for aseptic loosening or subsidence. The mean preoperative WOMAC scores (P: 12.8; S: 5.6; F: 51.8) had improved significantly at follow-up (P: 9.7;, S: 4.3; F: 37.6) (p<0.05). The mean Merle D'Aubigné score went from a pre-op of 8.2 (SD: 2.8; range 1 to 14) to a mean of 15.3 (SD: 2.6; range 7 to 18) (p<0,05) at the latest follow-up. During the follow-up period, 3 hips dislocated (4.5%). Each event happened prior to six months after surgery. Only one of these cases dislocated twice. Closed reduction was performed in all cases. None required revision surgery subsequently, and they all remained stable. The stem survivorship is 98.4% at 5 years (0.95 CI: 93–100) and 97.4% at 7.5 years (0.95 CI: 88.9–100). Stem subsidence of 0 to 5 mm was considered as not clinically significant (n=20; 30%). Stem subsidence of 5 to 10 mm occurred in 5 hips (7.6%)and stem subsidence greater than 10 mm only occurred in one hips (1.5%). The third generation Wagner SL conical revision femoral stem has a lower rate of complication than its preceding generations, and is comparable to modular stems performance reported in current literature. These results motivate the authors to continue using monoblock conical revision femoral stems

Introduction. Cementless grit-blasted tapered-wedge titanium femoral stems are being used with increasing frequency in hip arthroplasty because of excellent long-term outcomes. However, periprosthetic femur fracture is a potentially worrisome phenomenon in these types of femoral stems. The aim of this study is to report the incidence of stem loosening in association with periprosthetic femur fractures following hip arthroplasty using cementless grit-blasted tapered-wedge stems. Materials & Methods. A total of 36 Vancouver Type B1 and B2 periprosthetic femur fractures following either hemiarthroplasty or total hip arthroplasty using cementless grit-blasted tapered-wedge titanium femoral stems (GB group) were identified from a retrospective review of the medical records at three participating academic institutions. The control group consisted of 21 Vancouver Type B1 and B2 periprosthetic femur fractures following either hemiarthroplasty or total hip arthroplasty using cementless proximal porous-coated femoral stems (PC group) at the same institutions during the same period of the study. All femoral stems included in this study had been a well-fixed state before the occurrence of periprosthetic femur fractures. All patients in both groups were treated surgically with either open reduction and internal fixation or femoral stem revision. Femoral stem stability was assessed by preoperative radiographs and was confirmed by intraoperative scrutinization. The incidence of stem loosening was compared between the groups. Results. There was no significant difference between the groups with respect to demographic data including age, gender, body mass index, primary diagnosis, Dorr types of proximal femur, and time to fracture. All fractures occurred from low-energy mechanisms. Mean age at the time of hip arthroplasty was 54.5 years in the GB group and 57.0 years in the PC group. Mean time interval between hip arthroplasty and periprosthetic fracture was 49.6 months in the GB group and 44.4 months in the PC group. At the time of the last follow-up, 29 (80.6%) of 36 fractures was Vancouver B2 in the GB group, whereas only 3 (14.3%) of 21 fractures was Vancouver B2 in the PC group (P <0.001). Conclusions. High incidence of stem loosening was developed in association with periprosthetic femur fractures in previously well-fixed cementless grit-blasted tapered-wedge femoral stems in our population. We believe that this is an underreported phenomenon of these types of stem design

Aims

The purpose of this study was to compare the long-term results of primary total hip arthroplasty (THA) in young patients using either a conventional (CPE) or a highly cross-linked (HXLPE) polyethylene liner in terms of functional outcome, incidence of osteolysis, radiological wear and rate of revision.