Bone loss in the proximal tibia and distal femur is frequently encountered in revision knee replacement surgery. The various options for dealing with this depend on the extent of any bone loss. We present our results with the use of cementless metaphyseal metal sleeves in 103 patients (104 knees) with a mean follow-up of 43 months (30 to 65). At final follow-up, sleeves in 102 knees had good osseointegration. Two tibial sleeves were revised for loosening, possibly due to infection.

The average pre-operative Oxford Knee Score was 23 (11 to 36) and this improved to 32 (15 to 46) post-operatively. These early results encourage us to continue with the technique and monitor the outcomes in the long term.

Cite this article: Bone Joint J 2013;95-B:1640–4.

Introduction. This study was undertaken to evaluate the early results of a new implant system - the metaphyseal sleeve - in revision total knee replacement. The femoral and tibial metaphyseal sleeves are a modular option designed to deal with metaphyseal bone loss and achieve cementless fixation over a relatively wide area in the metaphysis. Methods. Over three years, femoral and/or tibial metaphyseal sleeves were implanted in 104 knees in 103 patients (54 male and 49 female). The clinical notes and radiographs of these patients were reviewed retrospectively. Thirty one patients had revision for infection, 42 for aseptic loosening, and 31 for instability, pain or stiffness. Eighty nine knees were revised as a single stage and 15 were done as two stage procedure. Minimum follow up is 12 months (average 18.5 months). Results. At the time of final follow up the sleeves showed good osseointegration in 102 knees with no evidence of loosening or subsidence. In two knees, a progressive radiolucency was noted around the metaphyseal sleeve 6 months after the revision procedure. Both these patients were symptomatic. The inflammatory markers were raised and Tc-99 bone scan showed increased uptake in the delayed phase. Loosening of the sleeve was confirmed on CT scans. SPECT scan raised suspicion of focal infection around the sleeve in one patient. Conclusion. The early results with the use of metaphyseal sleeves are encouraging. The sleeves provided firm fixation and structural support in patient with significant metaphyseal bone loss. This obviated the need for metal augments or bone graft. Further follow up will be required to evaluate the medium and long term results of this option. We believe the addition of cementless metaphyseal fixation is a useful tool in the armamentarium of the revision knee surgeon

Aim. One of the most challenging problems in total knee arthroplasty (TKA) is periprosthetic infection. A major problem that arises in septic revision TKA (RTKA) are extended bone defects. In case of extended bone defects revision prostheses with metaphyseal sleeves are used. Only a few studies have been published on the use of metaphyseal sleeves in RTKA - none were septic exclusive. The aim of our study was to determine the implant survival, achieved osseointegration as well as the radiological mid-term outcomes of metaphyseal sleeve fixation in septic two-stage knee revision surgery. Method. Clinical and radiological follow-up examinations were performed in 49 patients (25 male and 24 female). All patients were treated with a two-stage procedure, using a temporary non-articulating bone cement spacer. The spacer was explanted after a median of 12 weeks (SD 5, min. 1 – max. 31) and reimplantation was performed, using metaphyseal sleeves in combination with stem fixation. Bone defects were classified on preoperative radiographs using the Anderson Orthopaedic Research Institute (AORI) classification. During follow-up postoperative range of motion (ROM) was measured and radiographs were performed to analyse: (i) osseointegration (radiolucent lines and spot welds), (ii) leg alignment, (iii) patella tilt and shift. Results. All types of bone defects were found on the tibial (4× type 1, 7× type 2a, 26× type 2b, 9× type 3) as well as on the femoral side (1× type 1, 4× type 2a, 20× type 2b, 6× type 3). Mean follow-up time was 4.7 years (minimum 1 year). In total 12 knees (24.5%) had to be re-revised, all due to re-infection. We did not encounter any case of aseptic loosening. In 3 patients (6.8%) we detected an insufficient osseointegration, but no patient had to be re-revised due to only minimal or to the absence of symptoms and no clinical signs of loosening. The ROM (mean 93°, SD 20.6, min. 25° max. 125°) has shown very satisfying results at the time of follow-up. Malalignment was detected in 4 patients (10.3%), a patella tilt in 7 (19.4%) and a patella shift in 14 (48.3%). Conclusions. Metaphyseal Sleeves have shown very promising mid-term results regarding osseointegration and aseptic implant survival in RTKA with compromised metaphyseal bone stock. Our results indicate that they are a reliable fixation option in septic RTKA patients

There is no mathematical relationship between the internal diameter of the femoral metaphysis and diaphysis. Unless an infinite number of monolithic stems are available with variable metaphyseal and diaphyseal diameters, which is not economically possible, even in virgin cases, the surgeon has to decide if the stem is going to fit in the metaphysis or the diaphysis. It is not possible to match both.

In revision cases with a hollowed out metaphysis, the situation is much worse. As it is obviously easier to fit the diaphysis, this is what stems such as the AML and Wagner stem have done. They completely ignore the metaphysis and obtain fixation in the diaphysis. This is all well and good, but it means that the proximal femur is unloaded, like an astronaut in space. While, there will be some recovery due to removal of the toxins and local muscle pull, it will be incomplete. Furthermore, should sepsis occur, one is faced with the horror of removing a distally fixed implant.

Clearly, if proximal fixation, i.e. above the level of lesser trochanter could reliably be achieved, this would be preferable in terms of proximal loading leading to bone recovery and ease of removal should it be required. The only way that proximal loading can be achieved is if the metaphyseal and diaphyseal parts of the component can be varied infinitely. This clearly can only be achieved by using a modular stem.

The concern with modularity always has been fretting at the sleeve-stem locking mechanism with release of metal ions. The stem, which I have been using for the last 25 years, is the SROM stem. Fretting and ion release had never been an issue. As the components are made of a relatively soft titanium alloy, it is likely that the sleeve and the stem cold weld, thus, eliminating any movement and eliminating friction.

I have a follow-up of roughly 120 revision cases with a minimum follow-up of 5 years and a maximum follow-up of 22 years. I have no loosening in easy revision cases where a primary stem was used. I have had some loosenings in extremely difficult revision situations where a long bowed stem was required, but even then, the loosening rate is less than 3%.

I use this stem in primary situations, i.e. in about 80% of all the primaries I have done. This means I have done roughly 1500 cases or more. Other than some late infections, I have never, ever had any stem loosening in a simple case. Obviously, I have had loosenings in some cases, where we have been doing fancy shortening or de-rotation osteotomies, but none in simple primary cases. I would, therefore, suggest that the surgeon, if he wishes to use this stem, please try it out on some simple primary cases.

The ability to vary distal and proximal internal diameters and proximal geometry makes for easy surgery. I have been using this stem for 25 years and continue to use it in all my primary noncemented cases. I believe in the adage of “train hard and fight easy.” I think that surgeons should not get themselves into a situation where they are forced in a difficult case to use something they have never seen before.

The femur begins to bow anteriorly at the 200 mm level, but may bow earlier in smaller people. If the stem to be used is less than 200 mm, a straight stem can be used. If the stem is longer than 200 mm, it will perforate the anterior femoral cortex. I know this because I did this on a few occasions more than 20 years ago.

To use a long straight stem, there are two techniques. One can either do a diaphyseal osteotomy or one can do a Wagner split (extended trochanteric osteotomy). Both of these will put the knee in some degree of hyperextension, probably insignificant in the elderly, but it may be of significance in the young. In very young people, therefore, it may be preferable to use a bowed stem to avoid this degree of recurvatum.

There are two different concepts of loading. Diaphyseal osteotomy implies a proximal loading has been sought. The Wagner split ignores the proximal femur and seeks conical fixation in the diaphysis. There will be very little bone-bone contact between what remains of the attached femur and the detached anterior cortex so that it is important to ensure that the blood supply to the anterior cortex remains intact, preferably by using Wagner's technique, using a quarter-inch osteotome inserted through the vastus to crack the medial cortex. Current modularity is of two types. Distal modularity was attempted many years ago and was never successful.

Proximal modularity, as for example, the S-ROM stem, implies various sizes of sleeves fit onto the stem to get a proximal canal fill. In mid-stem modularity, the distal stem wedges into the cone. It has to be driven into where it jams and this can be somewhat unpredictable. For this reason, the solid Wagner stem has been replaced by the mid-stem modular. Once the distal femur is solidly embedded, the proximal body is then selected for height and version. The proximal body is unsupported in the mid-stem modular and initially, few fractures were noted at the taper junction. Cold rolling, shot peening and taper strengthening seem to have solved these problems.

There are a variety of types of osteotomy, which can be used for different deformities. With a mid-stem modular system, generally, all that needs to be done is a Wagner-type split and fixation is sought in the mid-diaphysis by conical reaming. No matter what stem is used, distal stability is necessary. This is achieved by flutes, which engage the endosteal cortex. The flutes alone must have sufficient rotational stability to overcome the service loads on the hip of 22 Nm.

I divide revision into three categories. In type one, the isthmus is intact, i.e. the bone below the lesser trochanter so that a primary stem can be used. In type two, the isthmus is damaged, i.e. the bone below the lesser trochanter, so a long revision stem is required. In a type three, there is more than 70 mm of missing proximal femur. The Wagner stem may be able to handle this on its own, but most other stems are better supported with a structural allograft cemented to the stem.

The reported long term results of mid-stem modular revision implants are good as in most, over 90% survivorship. The introduction of modularity appears to have overcome initial disadvantage of the Wagner stem, i.e. its unpredictability in terms of leg length.

Abstract. Approximately 20% of primary and revision Total Knee Arthroplasty (TKA) patients require multiple revisions, which are associated with poor survivorship, with worsening outcomes for subsequent revisions. For revision surgery, either endoprosthetic replacements or metaphyseal sleeves can be used for the repair, however, in cases of severe defects that are deemed “too severe” for reconstruction, endoprosthetic replacement of the affected area is recommended. However, endoprosthetic replacements have been associated with high complication rates (high incidence rates of prosthetic joint infection), while metaphyseal sleeves have a more acceptable complication profile and are therefore preferred. Despite this, no guidance exists as to the maximal limit of bone loss, which is acceptable for the use of metaphyseal sleeves to ensure sufficient axial and rotational stability. Therefore, this study assessed the effect of increasing bone loss on the primary stability of the metaphyseal sleeve in the proximal tibia to determine the maximal bone loss that retains axial and rotational stability comparable to a no defect control. Methods. to determine the pattern of bone loss and the average defect size that corresponds to the clinically defined defect sizes of small, medium and large defects, a series of pre-operative x-rays of patients with who underwent revision TKA were retrospectively analysed. Ten tibiae sawbones were used for the experiment. To prepare the bones, the joint surface was resected the typical resection depth required during a primary TKA (10mm). Each tibia was secured distally in a metal pot with perpendicular screws to ensure rotational and axial fixation to the testing machine. Based on X-ray findings, a fine guide wire was placed 5mm below the cut joint surface in the most medial region of the plateau. Core drills (15mm, 25mm and 35mm) corresponding to small, medium and large defects were passed over the guide wire allowing to act at the centre point, before the bone defect was created. The test was carried out on a control specimen with no defect, and subsequently on a Sawbone with a small, medium or large defect. Sleeves were inserted using the published operative technique, by trained individual using standard instruments supplied by the manufacturers. Standard axial pull-out (0 – 10mm) force and torque (0 – 30°) tests were carried out, recording the force (N) vs. displacement (mm) curves. Results. A circular defect pattern was identified across all defects, with the centre of the defect located 5mm below the medial tibial base plate, and as medial as possible. Unlike with large defects, small and medium sized defects reduced the pull-out force and torque at the bone-implant interface, however, these reductions were not statistically significant when compared to no bony defect. Conclusions. This experimental study demonstrated that up to 35mm radial defects may be an acceptable “critical limit” for bone loss below which metaphyseal sleeve use may still be appropriate. Further clinical assessment may help to confirm the findings of this experimental study. This study is the first in the literature to aim to quantify “critical bone loss” limit in the tibia for revision knee arthroplasty. Declaration of Interest. (a) fully declare any financial or other potential conflict of interest

Aim. Bone loss is a severe problem in septic revision total knee arthroplasty (RTKA). The use of porous coated metaphyseal sleeves is a promising treatment option for extended bone defects. The currently published mid-term results remain limited and no study has been focused exclusively on septic cases. Our aim was to determine the implant survivorship (with special focus on osseointegration) and the clinical and radiological mid-term outcome of metaphyseal sleeve fixation in septic RTKA surgery (minimum follow-up of 2 years). Method. Between January 2005 and September 2015, 57 patients underwent septic RTKA surgery using metaphyseal sleeves. In 56 patients (98,2 %) who underwent a total of 69 two stage revision procedures, clinical and radiological follow-up examinations were conducted. One patient (1,8 %) was lost to follow-up. The examinations included the American Knee Society Score (KSS), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), the SF-36 Health survey as well as radiographic measurement to determine if successful osseointegration had been achieved. Results. Thirteen knees (18.8%) had to be re-revised at the time of follow-up (mean 5.3 years, min. 2 – max. 11.2), all due to reinfection (Figure 1). We did not encounter any cases of aseptic loosening. The mean range of motion (92° ± 21°), SSS (7 ± 2), KSS (76 ± 19), WOMAC (70 ± 20), SF-36 MCS (55 ± 14) and SF-36 PCS (35 ± 9) have shown satisfying results. Conclusions. Metaphyseal sleeves have shown very promising mid-term results regarding clinical scores, osseointegration, and aseptic loosening. Our results are the first analysing the performance of metaphyseal sleeves in exclusively septic cases and show that they are a reliable fixation option in septic RTKA patients with severe bone loss

Prosthetic joint infections provide complex management, due to often-difficult diagnosis, need for multiple surgeries and increased technical and financial requirements. “2 in 1” single stage approaches have been advocated due to reduction in risks, costs and complications. This study aimed to investigate the results of single stage revision using metaphyseal sleeves for infected primary Total Knee Replacement (TKR). Prospective data was collected on all patients presenting with an infected primary TKR over an 8-year period (2009–17). All revision procedures were undertaken in a single stage using metaphyseal sleeves. 26 patients were included, 2 of which had previously failed 2 stage revision and 3 failed DAIR procedures. Mean age was 72.5. Mean BMI was 33.4. Median ASA 2. Mean time to revision was 3.5 years range 3 months to 12 years. Six patients had actively discharging sinuses at the time of surgery. Only 4 of the 26 patients had no positive microbiological cultures from deep tissue samples or joint aspirates. Only one patient has a recurrence of infection. This patient did not require further surgery and is treated on long term antibiotic suppression and is systemically well. There were statistically significant improvements in both the pain and function component of AKSS scores. There was no significant improvement in flexion, however mean extension and total range of movement both showed statistically significant improvements. Using Metaphyseal sleeves in single stage revision for infected TKR are safe and lead to an improvement in pain, function and have excellent efficacy for eradication of infection

Purpose of the study. This study was undertaken to evaluate the early results of a new implant system - the metaphyseal sleeve - in revision total knee replacement. The femoral and tibial metaphyseal sleeves are a modular option designed to deal with metaphyseal bone loss and achieve cementless fixation over a relatively wide area in the metaphysis. Methods. Over three years, femoral and/or tibial metaphyseal sleeves were implanted in 104 knees in 103 patients (54 male and 49 female). The clinical notes and radiographs of these patients were reviewed retrospectively. Thirty one patients had revision for infection, 42 for aseptic loosening, and 31 for instability, pain or stiffness. Eighty nine knees were revised as a single stage and 15 were done as two stage procedure. Minimum follow up is 12 months (average 18.5 months). Results. At the time of final follow up the sleeves showed good osseointegration in 102 knees with no evidence of loosening or subsidence. In two knees, a progressive radiolucency was noted around the metaphyseal sleeve 6 months after the revision procedure. Both these patients were symptomatic. The inflammatory markers were raised and Tc-99 bone scan showed increased uptake in the delayed phase. Loosening of the sleeve was confirmed on CT scans. SPECT scan raised suspicion of focal infection around the sleeve in one patient. Conclusion. The early results with the use of metaphyseal sleeves are encouraging. The sleeves provided firm fixation and structural support in patient with significant metaphyseal bone loss. This obviated the need for metal augments or bone graft. Further follow up will be required to evaluate the medium and long term results of this option. We believe the addition of cementless metaphyseal fixation is a useful tool in the armamentarium of the revision knee surgeon

Introduction. The primary aim of this study was to describe a baseline comparison of early knee-specific functional outcomes following revision total knee arthroplasty (TKA) using metaphyseal sleeves with a matched cohort of patients undergoing primary TKA. The secondary aim was to compare incidence of complications and length of stay (LOS) between the two groups. Methods. Patients undergoing revision TKA for all diagnoses between 2009 and 2016 had patient-reported outcome measures (PROMs) collected prospectively. PROMs consisted of the American Knee Society Score (AKSS) and Short-Form 12 (SF-12). The study cohort was identified retrospectively and demographics were collected. The cohort was matched to a control group of patients undergoing primary TKA. Results. Overall, 72 patients underwent revision TKA and were matched with 72 primary TKAs with a mean follow-up of 57 months (standard deviation (SD) 20 months). The only significant difference in postoperative PROMs was a worse AKSS pain score in the revision group (36 vs 44, p = 0.002); however, these patients still produced an improvement in the pain score. There was no significant difference in improvement of AKSS or SF-12 between the two groups. LOS (9.3 days vs 4.6 days) and operation time (1 hour 56 minutes vs 1 hour 7 minutes) were significantly higher in the revision group (p < 0.001). Patients undergoing revision were significantly more likely to require intraoperative lateral release and postoperative urinary catheterisation (p < 0.001). Conclusion. This matched-cohort study provides results of revision TKA using modern techniques and implants and outlines what results patients can expect to achieve using primary TKA as a control. This should be useful to clinicians counselling patients for revision TKA

Introduction. Revision TKA can be a difficult and complex procedure. Bone quality is commonly compromised and stem fixation is required in many cases to provide stability of the prosthetic construct. However, utilization of diaphyseal engaging stems adds complexity to the case and can present technical challenges to the surgeon. Press fit metaphyseal sleeves can provide stable fixation of the construct without the need for stems and allows for biologic ingrowth of the prosthesis. Metaphyseal sleeves simplify the revision procedure by avoiding the need to prepare the diaphysis for stems, alleviating the need for offset stems and decreasing the risk of intra-operative complications. The ability to obtain biologic fixation in the young patient is also appealing. This study reports on the author's mid-term experience with this novel technique. Methods. Between May 2007 and June 2009 the author performed 17 revisions TKA that utilized press-fit metaphyseal sleeves without stems on either the tibial side of the joint, the femoral side of the joint or both. Twenty six sleeves were implanted altogether (13 tibial, 13 femoral). Patients were limited to touch down weight bearing for 6 weeks post-operatively. The patients were followed prospectively with clinical and radiographic follow-up at routine intervals. Results. Average clinical and radiographic F/U for the cohort was 57 months (range 30 – 77). Fourteen of seventeen patients had a minimum of 4 years F/U. Average age at the time of surgery was 58 years (range 46–72) and average BMI was 32.4. Indications for the index revision included nine knees with aseptic loosening and / or osteolysis, two knees for septic loosening, two knees for instability and 4 knees for pain / stiffness or other causes. ROM at pre-op and latest F/U averaged 2–108 deg and 0–117 deg respectively. Knee Society Scores at pre-op and latest F/U averaged 35 and 86 respectively (range 57–100). Survivorship analysis revealed 25 of 26 sleeves (96%) to still be in situ at latest F/U. One tibial sleeve was revised at 30 months for septic loosening. Radiographic analysis revealed 22 of the remaining 25 sleeves (88%) to be ingrown. Two tibial sleeves and one femoral sleeve exhibit stable fibrous fixation and are asymptomatic. Conclusions. Press-fit metaphyseal sleeves utilized without stems appear to provide excellent stability of the revision TKA construct at mid-term F/U. Biologic fixation appears to be present in the majority of cases. This ability to obtain reliable osseointegration of the revision construct is appealing, especially in the younger revision patient. The sleeves have proven easy to use and there have been no intra-operative complications. This technique appears to provide a simple, but robust alternative when compared to revision TKA with stems in appropriate cases. Further F/U of this cohort is necessary to evaluate long term results

Introduction. Fixation remains a challenge in Revision TKR. Irregular and cavitary bone loss may precludeproper metaphyseal cementation and pressurization. Metaphyseal sleeves have been proposed to improve theinherent rotational stability of the implant bone interface. The goal of this study was to assess the effect of the use of metaphyseal sleeves on the quality of the cement fixation achieved. Methods. Fifty consecutive revision TKRs for AORI type 2 and 3 bone loss between January 2005 through January 2008 with average 2 years follow up were assessed retrospectively. Twelve patients were excluded for inadequate follow up. Nineteen patients with 26 cemented metaphyseal sleeves (15 tibiae and 11 femora) formed group 1 and 19 patients with 36 revision components (without metaphyseal sleeves) served as control (group 2). Patients were assessed clinically with knee society scores (KSS) and radiographically by quality of metaphyseal cement mantle and radiolucent lines(RLL). Groups were matched for pre-op bone loss and length of follow-up. Results. The presence of uniform cement mantle was 100% in group 1as opposed to only 70% (25 out of 36) in group 2. Incidence of metaphyseal RLL was 3.8% (1 out of 26 components) in group 1; as opposed to 16.7% (6 out of 36 components) in group 2. The average postoperative knee society and function score in group 1 was 90 and 80 and in group 2 was 88 and 81 respectively at final follow-up. Conclusion. Cemented metaphyseal sleeves along with press fit stems provided reproducible cement mantle with minimal radiolucencies when compared to similar cases in whom only stems were used. This minimal incidence of RLLs at 2 years possibly has potential for better survivorship over the long term

The number of revision knee arthroplasties performed is projected to rise dramatically in the coming years. Primary knee arthroplasties are also being performed in younger patients increasing the likelihood of multiple revision procedures. Reconstruction can be challenging with bone stock deficiencies and ligament incompetence. The aim of this study was to present our results of revision total knee arthroplasty using metaphyseal sleeve components to aid reconstruction. Sixty seven patients underwent revision total knee arthroplasty between September 2005 and November 2010 using metaphyseal sleeves. There were thirty one male and thirty six female patients. The indication for revision was aseptic loosening in thirty nine, sepsis in fifteen, malalignment in eight and instability in five patients. Thirty four patients had tibial sleeves, thirty patients had both tibial and femoral sleeves and three patients had femoral sleeves during revision. The patients were followed up for a mean of 32 months (Range 12–60) with outcome data collected prospectively. The mean revised oxford knee scores for the patients improved from 15 (Range 2 to 29) preoperatively to 33 (Range 20 to 45) postoperatively. Mean arc of flexion following revision was 87 degrees (Range 55 to 120). Seventy six percent of patients were satisfied or very satisfied with the result of the revision surgery. There have been no radiographic complications specific to the sleeves and no re-operations. There has been one recurrence of infection in a patient revised for sepsis. This has been managed with suppressive antibiotics due to patient co-morbidities. Metaphyseal sleeves are an effective adjunct in revision knee arthroplasty. We have had good results with their use. To our knowledge no larger series has been presented or published

Aims. Enhanced perioperative protocols have significantly improved patient recovery following primary total knee arthroplasty (TKA). Little has been investigated the effectiveness of these protocols for revision TKA (RTKA). We report on a matched group of aseptic revision and primary TKA patients treated with an identical pain and rehabilitation programmes. Methods. Overall, 40 aseptic full-component RTKA patients were matched (surgical date, age, sex, and body mass index (BMI)) to a group of primary cemented TKA patients. All RTKAs had new uncemented stemmed femoral and tibial components with metaphyseal sleeves. Both groups were treated with an identical postoperative pain protocol. Patients were followed for at least two years. Knee Society Scores (KSS) at six weeks and at final follow-up were recorded for both groups. Results. There was no difference in mean length of stay between the primary TKA (1.2 days (0.83 to 2.08)) and RTKA patients (1.4 days (0.91 to 2.08). Mean oral morphine milligram (mg) equivalent dosing (MED) during the hospitalization was 42 mg/day for the primary TKA and 38 mg/day for the RTKA groups. There were two readmissions: gastrointestinal disturbance (RTKA) and urinary retention (primary TKA). There no were reoperations, wound problems, thromboembolic events or manipulations in either group. Mean overall KSS for the RTKA group was 87.3 (45 to 99) at six-week follow-up and 89.1 (52 to 100) at final follow-up (mean 3.9 years, (3.9 to 9.0)). Mean overall KSS for the primary group was 89.9 (71 to 100) at six-week follow-up and 93.42 (73 to 100) at final follow-up (mean 3.5 years (2.5 to 9.2)). Conclusion. An identical pain and rehabilitation protocol used for primary TKA patients can enable certain full-component aseptic RTKA patients to have a similar early functional outcome. Cite this article: Bone Joint J 2020;102-B(6 Supple A):96–100

Introduction. Revision knee arthroplasty is an increasingly common procedure and can be challenging in the presence of bone defects, ligament instability and soft-tissue deficiencies. Current treatment options in addressing tibial and femoral bone loss in the revision setting include cement, morselised or structural allograft, metal wedges and augments and custom or hinge prosthesis. The aim of this study is to describe our early experience using unique femoral and tibial metaphyseal sleeves as an alternate for dealing with significant tibial and femoral bone loss. Methods. Porous stepped metaphyseal sleeves were implanted during twenty revision total knee replacements in eleven men and nine women who had an average age of 73.3 years at the time of the procedure. The indications included aseptic loosening in nineteen cases and second stage reimplantation in one case. Bone defects in tibia and femur were classified intra operatively according to AORI classification. All patients were prospectively followed clinically and radiographically for a mean follow up of sixteen months (range 12-26 months). Results. There were no periprosthetic fractures or complications related to the insertion and impaction of the sleeves. The mean length of stay was 9 days (range 5-20 days). Clinical review at the latest follow up revealed no evidence of instability and a good final range of motion (mean 0 to 95 degrees). Radiographs demonstrated reestablishment of joint line, neutral mechanical axis (mean -5 degrees valgus) and signs of stable osteointegration. No cases of progressive osteolysis, loosening or subsidence were noted. Discussion. The use of metaphyseal sleeves may facilitate in making revision TKA in the setting of severe bone loss a more reproducible, predictable, and successful option that offers biologic fixation leading to long-term implant stability and survival

The April 2014 Knee Roundup. 360 . looks at: mobile compression as good as chemical thromboprophylaxis; patellar injury with MIS knee surgery; tibial plateau fracture results not as good as we thought; back and knee pain; metaphyseal sleeves may be the answer in revision knee replacement; oral tranexamic acid; gentamycin alone in antibiotic spacers; and whether the jury is still out on unloader braces

Introduction:. Non-cemented, porous-coated metaphyseal sleeves have been designed to improve biologic fixation and stability in revision total knee arthroplasty (TKA) with major bone defects. The aim of this study was to evaluate the clinical results and osteointegration of these sleeves in major bone loss. Materials and Methods:. Between 2008 and 2011, 24 revision TKAs with major bone loss were reconstructed with non-cemented, porous-coated proximal sleeve (DePuy, Warsaw, IN). All patients were prospectively followed for a minimum of 2 years. Indications for use of sleeves were major metaphyseal tibial and femoral bone loss, younger age, and higher activity level. Osteointegration around the sleeves were classified as: . –. Grade 1: Complete osteointegration in all views without any demarcation. –. Grade 2: Sleeves that are not completely osteointegrated but they are stable. Grade 2A: Demarcation less than 2 mm on any view. Grade 2B: Demarcation more than 2 mm on any view . –. Grade 3: Sleeves that are not osteointegrated and unstable with evidence of subsidence. Grade 3A: Subsidence less than 2 mm on any view. Grade 3B: Subsidence more than 2 mm on any view. Results:. Mean range of motion and Knee Society Scores were 108 degrees and 92 respectively. 14 cases were revised for aseptic loosening and 10 cases for infection (which were treated with two stage revision arthroplasty). There was no malalignment, subsidence or re-revision at final follow-up. All sleeves were osteointegrated with majority grade 1 or 2a. Discussion and conclusion:. Short-term results of non-cemented metaphyseal sleeves in major bone loss for loosening of infection demonstrated excellent clinical results and osteointegration

Three basic design concepts of cementless femoral fixation have emerged. They include: anatomic designs, straight stem designs, and tapered designs. In addition, there have been modular designs. The most successful have been designs that have a metaphyseal sleeve with a tapered stem. A more recent newer concept has been the double taper neck designs which have not performed well in general. Anatomic Stem Designs: The rationale for an anatomic stem design was to design a component that matched the sagittal plane bow of the femur. The APR (Centerpulse, Austin, Texas) and the PCA (Howmedica, Rutherford, New Jersey) were the initial designs. Although these designs provided excellent micromotion stability, they are not used in their present length today because they could not fit in to all femurs. Straight Stem Designs: The concept of a straight stem design was to machine the femur to accept the prosthesis. This was done with diaphyseal reaming, proximal broaching, and preparing a proximal triangle to accommodate the proximal metaphyseal portion of the stem. These had previously, and still do, come in proximally coated and distally coated designs. They have proven to be durable long term. The AML fully coated stem (DePuy, Warsaw, Indiana) was and still is the prototype device. Tapered Stem Designs: The most popular designs today are the tapered stems. They are inserted either by a broach only, or ream and broach technique. Some only taper in the ML plane and are flat in the AP plane. These are called ML taper or blade devices (Taperloc and Trilock). These are usually inserted broach only. Some have a double taper with proximal fill and include the Zweymuller stem (Zimmer, Warsaw, Indiana), the Omnifit stem (Stryker, Mahwah, New Jersey), the Summit stem, and the Corail stem (both DePuy, Warsaw, Indiana). Some are hydroxyapatite coated (Omnifit and Corail), some are porous coated (Summit), and some are only grit blasted (Zweymuller). Some are broach only including the Zweymuller and Corail, and some are broach and ream including the Omnifit and Summit. Some are tapered throughout, one of which is a Wagner type design, Trilogy (Zimmer, Warsaw, Indiana). These Wagner type devices are useful in abnormal anatomy (CDH and Perthes). Modular Stem and Dual Modular Neck Designs: Metaphyseal sleeve modular stem designs are extremely versatile and can be inserted press fit into just about any femoral anatomy. They are most commonly utilised in cases of hip dysplasia with marked femoral anteversion. The S-ROM device is the prototype design. The long term concern with these as well as the double neck tapered devices is fretting and corrosion at the extra modular junctions. Short Stem Designs: Short stem designs were developed to provide metaphyseal only fixation and to enable easy insertion through small incision techniques, especially those performed through anterior and antero-lateral approaches

The management of bone loss in revision total knee replacement (TKA) remains a challenge. To accomplish the goals of revision TKA, the surgeon needs to choose the appropriate implant design to “fix the problem,” achieve proper component placement and alignment, and obtain robust short- and long-term fixation. Proper identification and classification of the extent of bone loss and deformity will aid in preoperative planning. Extensive bone loss may be due to progressive osteolysis (a mechanism of failure), or as a result of intraoperative component removal. The Anderson Orthopaedic Research Institute (AORI) is a useful classification system that individually describes femoral and tibial defects by the appearance, severity, and location of bone defects. This system provides a guideline to treatment and enables preoperative planning on radiographs. In Type 1 defects, femoral and tibial defects are characterised by minor contained deficiencies at the bone-implant interface. Metaphyseal bone is intact and the integrity of the joint line is not compromised. In this scenario, the best reconstruction option is to increase the thickness of bone resection and to fill the defect with cancellous bone graft or cement. Type 2 defects are characterised by deficient metaphyseal bone involving one or more femoral condyle(s) or tibial plateau(s). The peripheral rim of cortical bone may be intact or partially compromised, and the joint line is abnormal. Reconstruction options for a Type 2A defect include impaction bone grafting, cement, or more commonly, prosthetic augmentation (e.g. sleeves, augments or wedges). In Type 2B defects, metaphyseal bone of both femoral condyles or both tibial plateaus is deficient. The peripheral rim of cortical bone may be intact or partially compromised, and the joint line is abnormal. Options for a Type 2B defect include impaction grafting, bulk structural allograft, prosthetic augmentation, metaphyseal sleeves (in some cases), or metaphyseal cones. Finally, in the presence of a Type 3 deficiency, both metaphyseal and cortical bone is deficient and there is partial or complete disruption of the collateral ligament attachments. In this case, the most commonly used reconstruction options include hinged implants or megaprostheses with or without bulk structural allograft, prosthetic augmentation, and/or metaphyseal/diaphyseal sleeves or cones. Today, we are fortunate to have a wide variety of options available to aid in reconstruction of a revision TKA with massive bone loss. Historically, use of cement, bone grafting, or use of a tumor-type or hinged implant were considered the main options for reconstruction. The development and adoption of highly porous sleeves and cones has given the surgeon a new and potentially more durable option for reconstruction of previously difficult to treat defects. Using radiographs and computed tomography, surgeons are able to preoperatively classify bone loss and anticipate a reconstruction plan based upon the classification; however, it is always important to have several back-up options on hand during revision surgery in the event bone loss is worse than expected

Most problems encountered in complex revision total knee arthroplasty can be managed with the wide range of implant systems currently available. Modular metaphyseal sleeves, metallic augments and cones provide stability even with significant bone loss. Hinged designs substitute for significant ligamentous deficiencies. Catastrophic failure that precludes successful reconstruction can be encountered. The alternatives to arthroplasty in such drastic situations include knee arthrodesis, resection arthroplasty and amputation. The relative indications for the selection of these alternatives are recurrent deep infection, immunocompromised host, and extensive non-reconstructible bone or soft-tissue defects