The cement in cement technique for revision total hip arthroplasty (THA) has shown good results in selected cases. However, results of its use in the revision of hemiarthroplasty to THA has not been previously reported. Between May 1994 and May 2007 28 (20 Thompson's and 8 Exeter bipolar) hip hemiarthroplasties were revised to THA in 28 patients using the cement in cement technique. All had an Exeter stem inserted at the time of revision. Clinical and operative data were collected prospectively. Clinical evaluation was by the Charnley, Harris and Oxford. Hip scores and radiographs were analysed post-operatively and at latest follow up. The mean age at time of hemiarthroplasty revision was 80 (35 to 93) years. The reason for revision was acetabular erosion in 12 (43%), recurrent dislocation in eight (29%), aseptic stem loosening in four (14%), periprosthetic fracture in two (7%) and infection in a further two (7%) patients. No patient has been lost to follow up. Three patients died within three months of surgery. The mean follow up of the remainder was 50 (16 to 119) months. Survivorship with revision of the femoral stem for aseptic loosening as the endpoint was 100%. Three cases (11%) have since undergone further revision, one for recurrent dislocation, one for infection, and one for periprosthetic fracture. The cement in cement technique can be successfully applied to revision of hip hemiarthroplasty to THA. It has a number of advantages in this elderly population including minimising bone loss, blood loss and operative time

This study aimed to analyze the effect of two different techniques of cement application: cement on bone surface (CoB) versus cement on bone surface and implant surface (CoBaI) on the short-term effect of radiolucent lines (RLL) in primary fully cemented total knee arthroplasties (TKA) with patella resurfacing. 379 fully cemented TKAs (318 patients) were included in this monocentric study. Preoperative and postoperative at week 4 and 12 month after surgery all patients had a clinical and radiological examination and were administered the Oxford Knee Score (OKS). Cement was applied in two different ways among the two study groups: cement on bone surface (CoB group) or cement on bone surface and implant surface (CoBaI group). The evaluation of the presence of RLL or osteolysis was done as previously described using the updated Knee Society Radiographic Evaluation System. The mean OKS and range of motion improved significantly in both groups at the 4-week and 12-month follow-up, with no significant difference between the groups (CoB vs. CoBaI). RLL were present in 4.7% in the whole study population and were significantly higher in the CoBaI group (10.5%) at the 4-week follow-up. At the 12-month follow-up RLL were seen in 29.8% of the TKAs in the CoBaI group, whereas the incidence was lower in the CoB group (24.0% (n.s.)). There were two revisions in each group. None of these due to aseptic loosening. Our study indicated that the application of bone cement on bone surface only might be more beneficial than onto the bone surface and onto the implant surface as well in respect to the short-term presence of RLL in fully cemented primary TKA. The long-term results will be of interest, especially in respect to aseptic loosening and might guide future directions of bone cement applications in TKA

In North America, cementless femoral replacement has all but replaced cementing and cement technique is at risk for becoming a lost art. Published results of cemented femoral components with a well-designed femoral component and good surgical technique are excellent and equivalent to cementless technology. With an increasing focus on cost as part of value-based care, consideration for returning to cement for a select population is appropriate. Furthermore, there are patient populations that may benefit from a cemented femur with registries demonstrating superior short term outcomes. These include the elderly and patients with osteoporotic femurs. The goal of femoral cementing is to maximise the interdigitation of bone cement with metaphyseal trabecular bone and the irregular surface of the endosteum while at the same time minimizing the risk of embolization. The steps for femoral cementing include:cFemoral broaching – understand the relationship between the broach and stem as it relates to cement mantle thickness; Canal preparation; Gentle curetting to remove loose cancellous bone; Pressurised lavage to remove fat and marrow elements – this decreases the risk of embolization and enhances the strength of the bone-cement interface; Dry the canal – suction, adrenaline soaked sponge – this minimises bleeding and enhances the strength of the bone cement interface; Cement preparation – vacuum mix or centrifuge the bone cement – this minimise large voids that weaken the bone cement; Cement insertion – insert in a retrograde fashion and pressurise the cement – this optimises the cement column and the bone cement interface; Stem insertion – insert slowly with a system that centralises the stem – this prevents mantle defects that have been associated with stem loosening

The first rule in properly cementing a femoral component is obtaining adequate exposure of the proximal femur. This is achieved reproducibly in anterior approach surgery with anterior and superior capsulotomy, combined with release of the conjoined tendon from the inner trochanter and piriformis tendon retraction, or flip behind the trochanter. This will be demonstrated. The steps of cementation are well established, and not specific to one approach. They involve entry to the proximal femur in a lateral and posterior position, achieving central alignment within the proximal femur with the broach, application of a cement restrictor to a point 1.5 to 2cm distal to the proposed tip of the implant, appropriate preparation of the cancellous bone to receive the cement, applying cement in a sufficiently doughy state to be able to achieve penetration into the cancellous bone, and mechanical pressurization into that cancellous bone. We routinely apply cement directly to the proximal aspect of the femoral component as the cement sticks to the metal, preventing marrow contents generated during the insertion from contacting the metal. In discussing the factors contributing to a dry surgical field, the importance of relative hypotension achieved from regional anesthesia cannot be overstated

Introduction. Cement pressurisation in the distal humerus is technically difficult due to the anatomy of the humeral intramedullary (IM) cavity. Conventional cement restrictors often migrate proximally or leak, reducing the effect of pressurisation during implantation. Theoretically with a better cement bone interdigitation, the longevity of the elbow replacement can be improved. The aim of this cadaveric study was to evaluate the usefulness of a novel technique for cementation. Method. Eight paired fresh frozen cadaveric elbows were randomly allocated to conventional cementing techniques or cementing using a paediatric foley catheter as a temporary restrictor. The traditional cementing technique consisted of canal preparation using irrigation, brushing and drying prior to cementation, with no use of a cement restrictor. The new technique involved same canal preparation but prior to cementation a size 8 foley catheter was introduced and the balloon inflated to act as a temporary cement restrictor. The humeri were cut into 10mm sections. Each slice was photographed and radiographed. This dual imaging technique was used to establish the best methodology for evaluation of cement penetration. Cement penetration was calculated as a ratio of the area of intra-medullary cavity occupied by the cement. Results. There was no significant difference between the photographic and radiographic method of measuring cement penetration. Cement penetration was significantly better in the foley catheter group (P = 0.002-0.037). The maximum penetration was observed in the most distal 2-5cm. Conclusion. The foley catheter technique consistently and significantly achieved a better cement interdigitation into the cancellous bone, without leaving a void in the cement. This study has demonstrated a new cementing technique for elbow arthroplasty, utilising a paediatric foley catheter as a temporary humeral intra-medullary plug, increasing cement pressurisation and restricting proximal cement migration. Future studies using this methodology will not require supplementation of photographs with radiographic analysis

Questions/purposes:. What factors influence tibial tray-cement interface bond strength? We developed a laboratory model to investigate this issue with the goal of providing technical recommendations to mitigate the risk of tibial tray-cement loosening. Methods:. Forty-eight size 4 Triathlon® tibial trays were cemented into an acrylic holder using two different cements: Simplex® and Palacos®; three different cementing times: early (low viscosity), per manufacturer (normal, medium viscosity), and late (high viscosity); two different cementation techniques: cementing tibial plateau only and cementing tibial plateau and keel; and two different fat (marrow) contamination conditions: metal/cement interface and cement/cement interface. A push-out test was applied at a velocity of 0.05 mm/s, and the load recorded continuously throughout the test at a rate of 10 Hz. The test was stopped when the plate debonded from the cement (i.e. the tray visibly separated from the acrylic support and the load dropped substantially). Statistical analysis was performed using Welch's t-tests and Cohen's d tests. Results:. Compared to cementing under manufacturer-recommended conditions (normal), late cementing reduced the interface strength of Simplex™ by 47%. Early cementing increased interface strength of Simplex by 48% and Palacos by 139%. Cementing the keel increased the bond strength of Simplex™ 153% and Palacos™ 243% and over the respective normal cementing of the plateau only. Fat contamination of the metal-cement interface reduced the interface strength to practically zero (−99% Simplex and −91% Palacos), but by adding cement to the underside of the tibial tray prior to an insertion resulting in fat contamination, this was reduced to −65% in Simplex (the difference in strength between normal and fat contamination with the underside cemented was not statistically significant in Palacos). Conclusions:. Under laboratory conditions, a clean tibial tray-cement interface is strong, but much stronger when the keel is cemented. Earlier application of the cement to metal increases bond strength while later application reduces bond strength. Fat contamination of the tibial tray-cement interface reduces bond strength, but application of cement to the underside of the tibial tray prior to insertion substantially mitigates this. Clinical relevance: To maximize tibial tray-cement bond strength, 1) apply cement to the component soon after mixing, 2) thoroughly dry the entire tibial interface (plateau and keel), and 3) cement the keel as well as the plateau. These results suggest that clinical loosening at the tibial tray-cement interface can result from too late application of cement to the tray, and/or interface contamination by marrow or other fluid (blood or saline). The surgeon should consider applying cement to the undersurface of the component soon after mixing (while tacky). Cement placed into the keel region may also reduce the potential for marrow or other fluid contamination of the interface

Introduction. The use of stems in TKA revision surgery is well established. Stems off-load stress over a broad surface area of the diaphysis and help protect the metaphyseal interface areas from failure. Stems can provide an area of extra fixation. Uncemented Stems: Advantages – Expeditious; Compatible with intramedullary based revision instrumentation; Easy to remove if necessary; By filling diaphysis they help guarantee axial alignment. Disadvantages - They help off load stress, but how much fixation do they really provide?; They don't fit all canal deformities, and under some circumstances can actually force implants into malalignment; ? potential for end of stem pain. Cemented Stems: Advantages - Cemented stem adds fixation in fresh metaphyseal and diaphyseal bone; Proven 10-year track record; Allow the surgeon to adjust for canal geometry abnormalities. Disadvantages - More difficult to remove if required; They don't fill the canal so they don't guarantee alignment as well under most circumstances. Results:. Favorable results with uncemented and cemented stems have been reported in several series; Cemented stems have longer term data. Technique Issues: Uncemented Stems - Take advantage of offset bolts, tibial trays, stems to fit the stem/implant to the patient's anatomy. Don't let the stem force you into suboptimal implant position; Longer stems can be narrower but help engage more diaphysis; Do a good job of restoring/uncovering cancellous bone in metaphysis for cement interdigitation. The cement provides the fixation. Cemented Stems - Intraoperative x-ray with trials helps guarantee optimal alignment; Use cement restrictors; Cement tibia/femur separately. Metaphyseal Fixation - Area of new emphasis; Cover and sleeves can improve cemented and uncemented fixation

Introduction. The use of stems in TKA revision surgery is well established. Stems off-load stress over a broad surface area of the diaphysis and help protect the metaphyseal interface areas from failure. Stems can provide an area of extra fixation. Uncemented Stems. Pros and Cons. Advantages. (1) Expeditious, (2) Compatible with intramedullary based revision instrumentation (3) Easy to remove if necessary (4) By filling diaphysis they help guarantee axial alignment. Disadvantages. (1) They help off load stress, but how much fixation do they really provide? (2) They don't fit all canal deformities, and under some circumstances can actually force implants into malalignment. (3) ? potential for end of stem pain. Cemented Stems. Pros and Cons. Advantages. (1) Cemented stem adds fixation in fresh metaphyseal and diaphyseal bone. (2) Proven 10-year track record. (3) Allow the surgeon to adjust for canal geometry abnormalities. Disadvantages. (1) More difficult to remove, if required. (2) They don't fill the canal so they don't guarantee alignment as well under most circumstances. Results. Favorable results with uncemented and cemented stems have been reported in several series. Cemented stems have longer term data. Technique Issues. Uncemented Stems. (1) Take advantage of offset bolts, tibial trays, stems to fit the stem/implant to the patient's anatomy. (2) Don't let the stem force you into suboptimal implant position. (3) Longer stems can be narrower but help engage more diaphysis. (4) Do a good job of restoring/uncovering cancellous bone in metaphysis for cement interdigitation. The cement provides the fixation. Cemented Stems. (1) Intra-operative x-ray with trials helps guarantee optimal alignment. (2) Use cement restrictors. (3) Cement tibia/femur separately. Metaphyseal Fixation. (1) Area of new emphasis. (2) Cones and sleeves can improve cemented and uncemented fixation

Revision of the humeral component in shoulder arthroplasty is frequently necessary during revision surgery. Newer devices have been developed that allow for easy extraction or conversion at the time of revision preserving bone stock and simplifying the procedure. However, early generation anatomic and reverse humeral stems were frequently cemented into place. Monoblock or fixed collar stems make accessing the canal from above challenging. The cortex of the Humerus is far thinner than the femur and stress shielding has commonly led to osteopenia. Many stem designs have fins that project into the tuberosities putting them at risk for fracture on extraction. Extraction starts with an extended deltopectoral incision from the clavicle to the deltoid insertion. The proximal humerus needs to be freed from adhesions of the deltoid and conjoined tendon. The deltopectoral interval is fully developed. Complete subscapularis and anterior capsular release to the level of the latissimus tendon permits full exposure of the humeral head. After head removal the stem can be assessed for loosening and signs of periprosthetic joint infection. The proximal bone around the fin of the implant should be removed from the canal. If possible, the manufacturer's extractor should be utilised. If not, then a blunt impactor can be placed from below against the collar of the stem to assist in extraction. With luck the stem can be extracted from the cement mantle. If there is no concern for infection, the cement-in-cement technique can be used for revision. Otherwise, attempts should be made to extract all the cement and cement restrictor, if present. The small cement removal tools from the hip set can be used and specialised shoulder tools are available. An ultrasound cement removal device can be very helpful. The surgeon must be particularly careful to avoid perforation of the humeral cortex. This is especially important when near the radial nerve as injury can occur. When a well-fixed stem is encountered, an osteotomy of the proximal humerus is necessary. The surgeon can utilise a linear cut with an oscillating saw along the bicipital groove for the length of the implant. An osteotome is used to crack the cement mantle allowing stem extraction. Alternatively, a window can be created to offer additional access to the cement mantle. In the event the surgeon has required an osteotomy or window, cerclage wires, cables or suture will be needed and when the bone is potentially compromised, allograft bone graft struts (tibial shaft) are used for additional support. Care is needed when passing cerclage wires to avoid injury to the radial nerve which is adjacent to the deltoid insertion. If infection is suspected or confirmed an ALBC spacer is placed. When single stage revision is planned both cemented and uncemented stem options are available. Cement placed around the humeral stem has been suggested to decrease infection incidence. Revision of cemented humeral stems is a continued challenge in revision shoulder surgery. Newer systems and reverse total shoulder options have improved the surgeon's ability to achieve good outcomes when revising prior shoulder arthroplasty

Total joint arthroplasty has proven to be efficient to relieve pain and regain mobility. In fact, most patients undergoing a total knee arthroplasty (TKA) are satisfied with their surgery (80 to 90%), yet 4 to 7% still complain of unexplainable pain and stiffness. Several authors have proposed that reactivity to the implant could explain this phenomenon. Still, no strong evidence supports this theory as of today. We aimed to determine the prevalence of metal and cement hypersensitivity in a cohort of patients with unexplained pain and stiffness after TKA. We retrieved data for a group of patients presenting unexplained pain and stiffness. We excluded all other potential known causes of pain. All patients were tested with a Lymphocyte Transformation Test from whole blood taps. We analysed data of hypersensitivity to metals (alloy particles of titanium and cobalt, aluminum, cobalt, nickel, zirconium, vanadium, molybdenum, cobalt, chromium and iron) and PMMA cement (bone cement monomer and particles). Fifty-three patients underwent a LTT for unexplained pain and stiffness after total knee arthroplasty between May 2012 and May 2015. The cohort consisted of 26 men and 27 women with a mean age of 66.3(±8.0) years. Six patients had no hypersensitivity (11.3%), leaving 88.7% of the cohort with hypersensitivity to metal and/or cement. Almost half the cohort of patients tested for PMMA was hypersensitive to cement (44.0%). The most common metal hypersensitivity was nickel (69.8%). Twelve patients presented sensitivity to only one metal (22.6%), whereas 35 patients were hypersensitive to more than one metal (66.0%). Eleven patients had revision surgery with a hypoallergenic prosthesis. Patients reported a significant diminution of pain as well as better knee function compared to preoperative status as early as 6 weeks postop, although some reported residual stiffness. The results of this study suggest that metal and/or cement hypersensitivity could play a role in cases of total knee arthroplasty with unexplained pain and stiffness. Randomised controlled clinical trials on the subject will be initiated by our team to further investigate this phenomenon

Introduction. Implant-cement debonding at the knee has been reported previously [1]. The strength of the mechanical interlock of bone cement on to an implant surface can be associated with both bone cement and implant related factors. In addition to implant surface profile, sub-optimal mixing temperatures and waiting times prior to cement application may weaken the strength of the interlock. Aims. The study aimed to investigate the influence of bone cement related factors such as mixing temperature, viscosity, and the mixing and waiting times prior to application, in combination with implant surface roughness, on the tensile strength at the interface. Materials and Methods. Tensile tests were carried out on two types of hand-mixed cement, high (HV) and medium viscosity (MV), sandwiched between two cylindrical Cobalt-Chrome coupons with either smooth (60 grit) or rough (20 grit) surface finishes. 144 Specimens were prepared with a cement thickness layer of 2.5 mm in customised rigs (Figure 1). The samples were grouped and tested at two mixing temperatures (23 and 19 degrees), at different mixing times (HV-30s, MV-45s). Waiting times after mixing were varied between early (1.5 min), optimal (4.5 min) or late (8 min); for HV and 4 min, 7.5 min and 11 min for MV cements. All the samples were cured for 24 hours prior to testing. The peak force and stress was calculated for all specimens. Results and Conclusion. Surface Finish: Rough surfaced samples had significantly higher (p < 0.05) mean tensile forces and stress than smooth samples at both 19 and 23 degrees across HV and MV cement types. Cement Type: MV cements, when applied to rough samples with waiting times of 4 minutes at 23 degrees, and 11 minutes at 19 degrees, resulted in the highest peak tensile forces, followed by 7.5 minutes at 23 and 19 degrees respectively (Figure 2). Temperature at different application times for rough and smooth samples: for MV cement, rough samples prepared at 23 degrees, 4 minutes, and smooth samples at 19 degrees, 7.5 minutes were found to be significantly better (p < 0.05) than their counterparts. For HV cement, 23 degrees was found to be better (p < 0.05) for smooth samples at applications times of 4.5 and 8 minutes and 19 degrees for application times of 1.5 minutes. No significant difference was noted for rough samples for the same. Application times at different temperatures for rough and smooth samples: at both 19 and 23 degrees, there were no differences between application times within the rough sample groups for HV or MV. However, for smooth samples, HV cement, tensile forces were significantly higher (p < 0.05) at 23 degrees in the following order; 8 minutes > 4.5 minutes > 1.5. The results show that implant surface roughness and cement mixing time, temperature, viscosity and application times affect the strength of the interlock at the interface

To report a rare case of successfully treated synchronous shoulder septic arthritis, total knee replacement infection and lumbar spondylodiscitis in a patient with rheumatoid arthritis. Fifty-six year old woman, with a history of rheumatoid arthritis diagnosed at twenty-five year old, and total knee replacement at fifty-four. Recently treated with etanercept, presented with acute inflammatory signs of the right shoulder in addition to right knee and lumbar back pain for 6 months. After a shoulder and knee arthrocentesis the diagnosis suspicion of shoulder septic arthritis and total knee replacement infection was confirmed. Therefore it was performed shoulder arthroscopic irrigation and debridement and the first of two stages knee revision, with implantation of antibiotic cement on cement articulating spacer. It was also diagnosed a L1–L2 and L4–L5 spondylodiscitis with dural compression documented on MRI, which determined surgical treatment. By a posterior approach it was performed instrumentation from T11 to L5, followed by L1–L2 and L4–L5 discectomy and interbody fusion with autograft. Shoulder and knee synovial fluid cultures where positive for Methicillin Sensible Staphylococcus aureus narrowing the broad-spectrum combination therapy to levofloxacin for six weeks, with symptomatic relieve and C-reactive protein and white blood cell count returning to normal values. Almost one year down the line the patient remained with no sign of infection, even under the influence of immunosuppressive therapeutic. She returned to her previous status concerning the rheumatologic disease and the second stage knee revision is being planned to happen on the short run. Rheumatoid arthritis patients are a high-risk group for septic arthritis considering, among others, the immunosuppressive therapeutics and the frequent history of arthroplasty. The presented case illustrates three different type of septic complication in the same patient. The timely and aggressive approach was the key factor for a good outcome

Small canals are usually in small people, but occasionally some normal-sized people have huge cortical thickness with a corresponding small canal. To give adequate strength to the cement mantle, either pure cement or cement/cancellous bone, it must be at least 2mm thick. If the medullary canal is 9mm or less, then the thickest stem, which can be used with cement will be 5mm. This stem is so small that under load, it may deform repetitively, i.e. cycle. If it does cycle, it will break up the cement mantle. In order to get in a stem large enough to prevent cycling, hard reaming will be required, thus, removing most of the cancellous bone so the cement interlock is poor. Small stems are also usually fairly short stems. With a follow-up of more than 15 years, inevitably, some lucency between the cement and bone occurs in zones one and seven. If the stem is long enough, that is of no significance. If the stem is short, i.e. 120mm or less, then the area of distal fixation becomes precariously small. For these reasons, if the canal is small, it is preferable to use a non-cemented stem. The reaming technique for a non-cemented stem is to reach endosteal cortical contact either circumferentially with a canal-filling stem or at the point of wedge for a wedge-shape stem. The metaphyseal bone may be poor quality in the elderly, but it is going to be removed anyway to load the endosteal cortex. This means that a large stem can be used, which is, therefore, stronger and less likely to undergo mechanical failure and fixation failure

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

Clearly uncemented hip stems are becoming more popular. They are working relatively well and avoiding the step of cementation is easier and much quicker. However, this speaker feels that well designed femoral stems with 25–30 years of proven successful fixation are perfectly good for elderly patients with 10, 15, and 20 year life expectancies. They are good for several reasons. They seal off bleeding from the femur essentially completely—particularly helpful in high anticoagulation patients. Also, addition of antibiotic cement would be expected to have a lower infection rate, and cases of gross osteopenia can be less likely to have fractures or undesired subsidence. There are a few basic points which can make a big difference in the quality of hip stem cementation. These points are: (1) After ordinary broaching, loose, mechanically incompetent bone needs to be removed. This is well done with canal brushes and large angled curettes. (2) The canal must be plugged distally a centimeter or two beyond the tip of the femoral prosthesis. (3) The femoral cavity needs to be as dry as possible at the time of cement introduction. This is one of the more difficult tasks to achieve perfectly. First is pulse lavage with an intramedullary nozzle. Next, I use epinephrine soaked sponges pulled completely out to length and introduced to fill the cavity completely—filling retrograde and packing tightly. Shortly before the cement is to be introduced, the epi sponges are changed to dry ones with the same type of firm, retrograde filling. The canal is commonly dried twice occasionally three times. Cement introduction: (1) A cement gun with long intramedullary nozzle is mandatory. (2) The cement must not be too runny, i.e. of too low a viscosity. You will have more trouble maintaining pressurisation with liquid runny cement, and you risk bleeding from the bone into the cement cavity significantly compromising the cementation. (3) The cement must be introduced retrograde with complete filling i.e. no voids, and not running out of cement to inject before the tip of the nozzle has reached the introitus, the entry point to the femoral cavity. Otherwise you wind up pulling out the nozzle itself out, leaving a void. (4) “Pressurisers,” that is, almost all that I have seen, do not really facilitate pressurisation. Once the canal is completely full with cement and the cement is getting stiffer, pressurisation by pushing at the introitus using your thumb over a lap pad creates tremendous pressurisation that can push cement beyond most cement plugs!. Introducing the femoral component: (1) Last, the femoral component is introduced rather slowly so that one maintains constant pressurisation by virtue of the volume displacement as the component goes to its proper level. Ideally the femoral component reaches its proper level just before the cement is really hard. You really can do this as you get the component 0.5 to1.0 cm. from the final level and impact it slowly as the cement comes to nearly complete hardness. The two worst things you can do— . 1. Have the prosthesis reach its desired level with the cement relatively runny and have the bone bleed into the cement and degrade the quality of the cement interdigitation. 2. Being too slow getting the prosthesis down to the desired level and having it stuck to high. Consistent, optimum cementation of the femoral component is difficult, but achievable and worth it! You have a component with good stress transfer, no undesired proximal stress shielding like some porous implants have; less bleeding from the canal; good 20+ year fixation, etc., etc

Purpose of Study. To assess the results of Revision Hip Surgery in which a less invasive technique was utilized in situations where a number of different options was available. Method. The authors rely on an experience of 3,445 hip arthroplasties by a single surgeon over a period of 20 years, of which approximately 20% were revision cases. Of these 617 cases, we report on 175 in which a minimally invasive option was taken. This does not apply to the skin incision, as all cases were adequately exposed. We have adopted this term to describe cases in which a surgical options was taken that resulted in the least morbidity and the shortest surgical time. We postulated that would lead to the best outcomes with the least complications. Acetabular revisions: 1) Isolated polyethylene exchange. 2) Liner revision with cement technique in cases of cup malposition or poor locking mechanism. 3) Revision of cup with a primary prosthesis with significant medial bone loss. Stem revisions: 1) Cement on cement technique. 2) Strut graft and primary stem. Results. We found a very low complication rate utilizing these methods: Fatal pulmonary emboli: 0 Sepsis: 2 Dislocations 3 Repeat revisions 3. Conclusion. Revision surgery offers many challenges that tend to be compounded with successive operations. We believe that good results can be achieved when a philosophy of minimally invasive surgery is adopted. NO DISCLOSURES

Fixation of cemented femoral stems is reproducible and provides excellent early recovery of hip function in patients 60–80 years old. The durability of fixation has been evaluated up to 20 years with 90% survivorship. The mode of failure of fixation of cemented total hip arthroplasty is multi-factorial; however, good cementing techniques and reduction of polyethylene wear have been shown to reduce its incidence. The importance of surface roughness for durability of fixation is controversial. This presentation will describe my personal experience with the cemented femoral stem over 30 years with 3 designs and surface roughness (RA) ranging from 30 to 150 microinches. Results. Since 1978, three series of cemented THA have been prospectively followed using periodic clinical and radiographic evaluations. All procedures were performed by the author using the posterior approach. Excellent results and Kaplan-Meier survivorship ranges from 90% to 99.5% in the best case scenario were noted at 10 to 20 year follow-up. Conclusion. With a properly-designed femoral stem, good cement technique, proper cement mantle, and surface roughness of 30 to 40 microinches, the cemented femoral stem provides a durable hip replacement in patients 60 to 80 years old with up to 95% survivorship at 10 to 20 year follow-up

The amount of bone loss due to implant failure, loosening, or osteolysis can vary greatly and can have a major impact on reconstructive options during revision total knee arthroplasty (TKA). Massive bone loss can threaten ligamentous attachments in the vicinity of the knee and may require use of components with additional constraint to compensate for associated ligamentous instability. Classification of bone defects can be helpful in predicting the complexity of the reconstruction required and in facilitating preoperative planning and implant selection. One very helpful classification of bone loss associated with TKA is the Anderson Orthopaedic Research Institute (AORI) Bone Defect Classification System as it provides the means to compare the location and extent of femoral and tibial bone loss encountered during revision surgery. In general, the higher grade defects (Type IIb or III) on both the femoral and tibial sides are more likely to require stemmed components, and may require the use of either structural graft or large augments to restore support for currently available modular revision components. Custom prostheses were previously utilised for massive defects of this sort, but more recently have been supplanted by revision TKA component systems with or without special metal augments or structural allograft. Options for bone defect management are: 1) Fill with cement; 2) Fill with cement supplemented by screws or K-wires; 3) Morselised bone grafting (for smaller, especially contained cavitary defects); 4) Small segment structural bone graft; 5) Impaction grafting; 6) Porous metal cones or sleeves 7) Massive structural allograft-prosthetic composites; 8) Custom implants. Of these, use of uncemented highly porous metal metaphyseal cones in combination with an initial cemented or partially cemented implant has been shown to provide versatile and highly durable results for a range of bone defects including those previously requiring structural bone graft. The hybrid fixation combination of both cement and cementless fixation of an individual tibial or femoral component has emerged as a frequent and often preferred technique. Initial secure and motionless interfaces are provided by the cemented portions of the construct, while subsequent bone ingrowth to the cementless porous metal portions is the key to long term stable fixation. As bone grows into the porous portions there is off loading and protection of the cemented interfaces from mechanical stresses. While maximizing support on intact host bone has been a longstanding fundamental principle of revision arthroplasty, this is facilitated by the use of metaphyseal cones or sleeves in combination with initial fixation into the adjacent diaphysis. Preoperative planning is facilitated by good quality radiographs, supplemented on occasion by additional imaging such as CT. Fluoroscopically controlled x-ray views may assist in diagnosing the loose implant by better revealing the interface between the implant and bone and can facilitate accurate delineation of the extent of bone deficiency present. Part of the preoperative plan is to ensure adequate range and variety of implant choices and bone graft resources for the planned reconstruction allowing for the potential for unexpected intraoperative findings such as occult fracture through deficient periprosthetic bone. While massive bone loss may compromise ligamentous attachment to bone, in the majority of reconstructions, the degree of revision implant constraint needed for proper balancing and restoration of stability is independent of the bone defect. Thus, some knees with minimal bone deficiency may require increased constraint due to the status of the soft tissues while others involving very large bone defects, especially of the cavitary sort, may be well managed with minimal constraint

When fixing a mid or distal periprosthetic femoral fracture with an existing hip replacement, creation of a stress-riser is a significant concern. Our aim was to identify the degree of overlap required to minimise the risk of future fracture between plate and stem. Each fixation scenario was tested using 4th generation composite femoral Sawbones®. Each sawbone was implanted with a collarless polished cemented stem with polymethyl methacrylate bone cement and cement restrictor. 4.5mm broad Peri-loc™ plates were positioned at positions ½, 1 and 2 shaft diameters (SD) proximal and distal to the tip of the femoral stem. Uni-axial strain gauges (medial and lateral longitudinal gauges, anterior and posterior torsional gauges) measured microstrain at tip of the femoral stem with a standard load of 500N in axial, 3-point lateral and composite torsion/posterior loading using an Instron machine. With axial loading fixation with 2SD proximal resulted in the least amount of strain, in both tension & compression, at the tip of the femoral stem. Fixation with 4 unicortical screws was significantly better than 2 alternating unicortical screws (mean microstrain difference 3.9 to 15.3, p<0.0001). With lateral 3-point loading fixation with 2SD proximal overlap and 2 alternating unicortical screws resulted in the least amount of strain, in both tension and compression, at the tip of the femoral stem (p<0.0001). With torsion & posterior displacement 2SD proximal fixation resulted in the least amount of rotational strain. There was no significant difference between 4 unicortical screws compared to 2 alternating unicortical screws (p>0.05 in 3 of 4 gauges). Fixation of midshaft or distal femoral fractures with a well-fixed total hip arthroplasty should have at least 2 shaft diameters of proximal overlap with a 4.5mm broad plate. It is not clear if 4 unicortical screws or 2 alternating screws are optimal

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 4cm 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 (OSCAR) 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 used 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 intraoperative x-ray can be very helpful to insure that all cement has been removed before reaming is initiated