Purpose: Prosthetic arthroplasty is the most common method of reconstruction of segmental bone defects following resection of bone sarcomas about the knee. The purpose of this study was to determine the survivorship of the reconstructions in short- and long-term follow-up. Methods: A retrospective study was performed on all patients diagnosed with a bone sarcoma between 1984 and 1995 who were treated with a limb-sparing osteoarticular resection and rotating hinge prosthetic knee arthroplasty. Prosthetic survival was calculated with endpoints of analysis based on any event, any prosthesis-related event and aseptic loosening of the prosthesis, which led to prosthetic revision, removal or limb amputation. Results: A total of 154 reconstructions were performed involving the distal femur (n=111) and proximal tibia (n=43). The median resection length was 155 mm (105–250mm) for the distal femur and 117 mm (85–150 mm) for the proximal tibia. All implants were fixed with polymethylmethacrylate cement. Early complications (within one year postoperatively) developed in fewer than 2 % of patients. Aseptic loosening accounted for the majority of events resulting in prosthetic failures (distal femur = 17 [median failure 34 mos]; proximal tibia = 10 [median failure 100 mos]). Polyethylene bushing wear was observed in seven patients (median time to replacement = 156 months). Conclusion: The early outcome of prosthetic arthroplasty was extremely favorable supporting this method of reconstruction following excision of high-grade bone sarcomas about the knee. Long-term survival of these prostheses is suboptimal and can be anticipated to be poor for the proximal tibia. Aseptic loosening continues to be the primary cause of prosthetic failure about the knee

Introduction. Implant malalignment is an important predictor of prosthetic failure following total knee arthroplasty (TKA). The purpose of this study was to determine the incidence of outliers for common alignment targets and the impact of surgeon volume and experience on the accuracy of implant alignment with current generation manual instrumentation. Methods. This study was a retrospective, multi-center, radiographic analysis of 1675 consecutive primary uncomplicated TKAs from seven surgeons at three academic and state-funded centers in the US and UK. Surgeons were categorized as “high-volume” (≥50 TKAs/year) and “high-experience” (≥5 years post-fellowship). Femorotibial, tibial varus/valgus, and posterior tibial slope angles were digitally measured using postoperative radiographs. Femorotibial (<2° or >8° valgus), tibial (> ±3° deviation from the neutral axis), and tibial slope (<0° or >7° of flexion for cruciate retaining, <0° or >5° of flexion for posterior stabilized) angle outliers were identified. The proportion of outliers among surgeons in each subgroup was compared. Results. When comparing high-and low-volume surgeons, the proportion of femorotibial (12% vs. 19%, p <0.0001), posterior slope (17% vs. 28%, p <0.0001), and total outliers (12% vs. 19%, p <0.0001) was significantly lower in the high-volume group. Furthermore, the proportion of knees with well-aligned implants in all three measurements (69% vs. 53%, p <0.0001) was significantly higher in the high-volume group. When comparing high-and low-experience surgeons, the proportion of femorotibial (14% vs. 17%, p = 0.046), tibial (9% vs. 6%, p = 0.030), posterior slope (19% vs. 26%, p <0.0001), and total outliers (14% vs. 17%, p = 0.006) was higher in the low-volume group. Furthermore, the proportion of knees with well-aligned implants in all three measurements (64% vs. 58%, p = 0.008) was significantly higher in the high-experience group. Conclusions. Low surgeon volume and experience predispose to implant malalignment following TKA, with surgical volume bearing a greater influence on alignment accuracy. Even among high volume, high experience surgeons, outliers in at least one standard alignment target occur in over 30% of cases with current standard instrumentation

Aims

To review the evidence and reach consensus on recommendations for follow-up after total hip and knee arthroplasty.

Background. Fractures of the femoral component are well reported complications that present a challenging task in revision total hip arthroplasty. Albeit being uncommon, with an incidence of 0.23–11%, the consequences can be devastating. Its extraction being a demanding undertaking that is potentially detrimental to the remaining host bone. Several techniques have been described to address this complex issue prior to revision: drilling of the exposed part of the femoral stem and attaching a threaded extraction device, surface undercutting with an extraction device wedged in, femoral trephine techniques, creation of a femoral cortical window, an extended femoral osteotomy procedure, as well as extraction by means of retrograde nail impaction. Here we present the modified technique we employed in the revision of a failed cementless extensively porous coated femoral component that had fractured at the neck-stem interface. Technique. The proximal femoral component was visualized and an orthopedic burr and a femoral osteotome employed surrounding the component. Utilizing a Midas Rex® MR7 drill with its metal cutting attachment, a circular recess was created in the shoulder of the femoral component. This facilitated the application of the distal end of a universal slap hammer. The component was retrieved successfully with no associated bone loss negating the need for a femoral osteotomy. Discussion. Revision hip arthroplasty is a perplexing field where unpredictable prosthetic failures require innovation to tackle the unique problems encountered. Our method allows a safe and efficient alternative in retrieving femoral components with no associated complications

Introduction. Augmented glenoid implants provide a new avenue to correct glenoid bone loss and can possibly reconcile current prosthetic failures and improve long-term performance. Biomechanical implant studies have suggested benefits from augmented glenoid components but limited evidence exists on optimal design of these augmented glenoid components. The aim of this study was to use integrated kinematic finite element analysis (FEA) model to evaluate the optimal augmented glenoid design based on biomechanical performance in extreme conditions for failure. Materials and Methods. Computer aided design software (CAD) models of two different commercially available augmented glenoid designs - wedge (Equinox®, Exactech, Inc.) and step (Steptech®, Depuy Synthes) were created per precise manufacturer's dimensions and sizes of the implants. Using FE modeling, these implants were virtually implanted to correct 20° of glenoid retroversion. Two glenohumeral radial mismatches (RM) (3.5/4mm and 10 mm) were evaluated for joint stability and implant fixation to simulate high risk conditions for failure. The following variables were recorded: glenohumeral force ratio, relative micromotion (distraction, translation and compression), and stress on the implant and at the cement mantle interface. Results. The wedged and step designs showed similar force ratio measurements with both RM [(wedge (3.5 mm: 0.69; 10 mm: 0.7) and step (4 mm: 0.72; 10 mm: 0.75)]. Surrogate for micromotion was a combination of distraction, translation and compression. As radial mismatch increased, both implants showed less distraction [wedge design (3.5 mm: 0.042 mm; 10mm: 0.030 mm); step design (4 mm: 0.04 mm; 10 mm: 0.027 mm)]. As radial mismatch increased, both implants showed more translation [wedge design (3.5 mm: 0.058 mm; 10mm: 0.062 mm); step design (4 mm: 0.023 mm; 10 mm: 0.063 mm)]. During compression measurements, the different designs did not follow the same pattern as their conformity setting changed. The wedge one decreased as radial mismatch increased, (at 3.5mm: 0.18 mm; at 10 mm: 0.10 mm) and the step design increased as its radial mismatch increased (at 3.5 mm: 0.19 mm; at 10 mm: 0.25 mm). Quantitatively, the step design showed higher risk of implant instability and loosening. As radial mismatch increased, the stress level on the backside of the implant increased as opposed to the stress levels on the cement mantle which decreased for both designs as the radial mismatch increased [wedged (3.5 mm: 2.9 MPa; 10mm: 2.6 MPa); step (3.5 mm: 4.4 MPa; 10 mm: 4.1 MPa)]. In this situation, the risk of loosening was higher for the step designwhich exceeded the endurance limit of the cement material (4 MPa). Discussion. Implant loosening and wear are associated with increased micromotion and high stress levels. Based on our FEA model, overall increased radial mismatch has an advantage of providing higher glenohumeral stability but not without tradeoffs, such as higher implant and cement mantle stress levels, and micromotion increasing the risk of implant loosening, failure or fracture over time, leading to poorer clinical outcomes and higher revision rates, especially when considering a step augmented glenoid design

Aims

The proximal tibia (PT) is the anatomical site most frequently affected by primary bone tumours after the distal femur. Reconstruction of the PT remains challenging because of the poor soft-tissue cover and the need to reconstruct the extensor mechanism. Reconstructive techniques include implantation of massive endoprosthesis (megaprosthesis), osteoarticular allografts (OAs), or allograft-prosthesis composites (APCs).

Aim. In patients with bone sarcoma, placing mega prostheses in the proximal tibia is associated with high rates of infection. In studies with small numbers of patients and short follow-up periods, silver-coated mega prostheses have been reported to lead to reduced infection rates. To the best of our knowledge, this study is the largest one that has compared the infection rates with titanium versus silver-coated mega prostheses in patients treated for sarcomas in the proximal tibia. Method. The infection rate in 98 patients with sarcoma or giant cell tumour in the proximal tibia who underwent placement of a titanium (n = 42) or silver-coated (n = 56) mega prosthesis. *. was assessed, along with the treatments administered for any infection. Results. As the primary end point of the study, the rates of infection were 16.7% in the titanium group and 8.9% in the silver group, resulting in 5-year prosthesis survival rates of 90% in the silver group and 84% in the titanium group. Overall, seven of 56 patients in the silver group (12.5%) developed periprosthetic infection. Two patients became infected after revision surgery due to mechanical failure of the prosthesis. In the titanium group, one patient developed a periprosthetic infection after revision surgery (which was carried out in 50% of patients) due to a mechanical prosthetic failure, leading to an overall infection rate of 19.0% (eight of 42). Overall, nine of 12 (75%) periprosthetic infections in the two groups occurred within the first 2 years postoperatively, if later revision surgery due to mechanical failure was not necessary. Whereas three of the eight patients in the titanium group (37.5%) ultimately had to undergo amputation due to infected proximal tibia replacement, these mutilating surgical procedures were necessary in the silver group in only one patient (14.3%). In the titanium group, two-stage revision surgery with a temporary antibiotic-impregnated cement spacer was ultimately successful in four of eight patients (50.0%), but this procedure was necessary in only one patient in the silver group (14.3%). Conclusions. The use of silver-coated prostheses reduced the infection rate in a relatively large and homogeneous group of patients. In addition, less aggressive treatment of infection was possible in the group with silver-coated prostheses

Ceramic-on-ceramic (CoC) total hip arthroplasty (THA) can produce articular noise during the normal activities, generating discomfort to the patient. THA noise has to be investigated also as a potential predictor and a clinical sign of prosthetic failure. An observational study has been carried out to characterize the noise in CoC cementless THA, and to analyze the related factors. A total of 46 patients with noisy hip have been enrolled in 38 months, within the follow-up protocol normally applied for the early diagnosis of ceramic liner fracture [1]. Noise recording was based on a high-quality audible recorder (mod. LS 3, Olympus, Japan) and a portable ultrasonic transducer (mod USB AE 1ch, PAC, USA). The sensors for noise recording were applied to the hip of the patient during a sequence of repeatable motorial activities (forward and backward walking, squat, sit in a chair, flexion and extension of the leg). Sessions were also video-recorded to associate the noise emission to the specific movements. Each noise event was initially identified by the operator and therefore classified by comparison to the spectral characteristics (duration, intensity and frequency) of the main noise types. Number and spectral characteristics of noise events were obtained and correlated to the factors describing the clinical status of the patient, the surgical approach, the prosthetic device implanted. The study investigated also the noise as a sign of implant failure, by comparison with the total number of implants failed in the cohort during the study. We observed three types of noise with the main spectral characteristics in agreement to the literature: clicking, squeaking and popping. Among the identified types of noise, squeaking showed the longest duration and the highest amplitude. The 63% of hip presented the emission of just one type of noise, while the remaining a mix of types. The movement with the highest presence of noise was walking, followed by squat. Correlation was found between the noise type and the dimension of the ceramic head (p<0.001), with the sizes of 32 mm more affected by squeaking that the smaller one. Squeaking appeared before during the follow-up than the other types of noise. The 35% (16/46) of the noisy hips were revised during the study. Among the revised hips, the 81% (13/16) were affected by impingement and/or severe damage of the prosthetic components. The antiversion of the cup (p=0.008), the presence of debris in the synovial fluid (p=0.021) and the average frequency of squeaking (p=0.006) were significant predictors for the revision, but it has to be mentioned that the squeaking data was obtained on a small subset of revised patients. Ultrasonic analysis did not show significant correlations. The study presented and validated an experimental procedure to analyze noisy hips in clinical trials. Noise is confirmed to be a significant parameter in the follow-up evaluation of ceramic THA

Pain following total hip arthroplasty is a relatively rare event. Several series place the incidence of some degree of pain post THA at approximately 5%. A systematic approach to determining etiology will direct treatment. Hip pain can be categorised as:. Extrinsic to the Hip. –. Spine +/− radiculopathy. –. Vascular disease. –. Metabolic (Paget's). –. Malignancy. Intrinsic to the Hip. Intracapsular/Implant. Loosening. Sepsis. Prosthetic failure. Osteolysis. Instability. Thigh pain. Stem tip pain. Hypersensitivity/ALVAL. Extracapsular. Iliopsoas tendonitis. Snapping Hip. Trochanter problems (bursitis). Heterotopic ossification. A full history and appropriate physical exam will direct the clinician. The use of routine radiographs, blood tests, and special tests (i.e., blood metal ions, advanced imaging techniques) will be discussed I detail

Introduction. The development of new megaprosthesis for the treatment of large bone defects has offered important opportunities to orthopedic oncologic surgeons for the replacement of skeletal segments such as the long bones of the upper and lower limbs and the relative joints. Our experience, treating non union and severe bone loss, has brought us, sometimes, to be confronted with the reality of some failures after unsuccessful attempts to reconstruct. Faced with certain radiological and / or clinical drastic situations we wanted to apply the principles of Biological Chamber and oncologic surgery with megaprosthetic replacement solutions. We implanted megaprosthesis with either 1 step or 2 steps (previous antibiotated spacer) technique depending on the septic patient conditions. The aim of this study is to retrospectively evaluate both clinical and radiological outcomes in patients underwented to a lower limb megaprosthesis implant and complications were recorded. Materials and Methods. In total, we treated 58 patients with megaprosthesis mono-and bi-articular subdivided as follows: proximal femur, distal femur, proximal tibia and total femur. The mean follow-up of patients is about 24 months (5 yrs max, min 6 months) with clinical and serial radiographic revaluations with standard methods (X-ray in 45 days, 3–6-12-18-24 months) as well as monitoring of blood parameters of inflammation for at least 2 months. Results. Despite the follow up average is not so long, the first patients have now reached five years of monitoring and in all cases we have had encouraging clinical results with good articulation of the segments, no somato-sensory or motorial defict and acceptable functional recovery. During surgery and, even more, in the pre-operative planning much attention should be given to the evaluation of the extensor apparatus preserving it and, when necessary, reinforcing it with tendon substitutes. Discussion. Megaprosthesis in traumatic and prosthetic failures can therefore be considered, in extreme cases appropriately selected, as a solution available to the orthopedic surgeon? In oncological surgery the opportunity to regive a function, although not ad integrum, to the patient is certainly an element of great fascination for the surgeon and an opportunity for the patient. Unfortunately, the high mortality associated with this disease does not allow us to have long-term follow-up. This then creates a lack of certainty about the survival of this type of prosthesis and the medium and long-term complications that may occur. Nevertheless, the patients treated by us should be considered as a oncologic patient, not because of the disease but for the limited therapeutic options available. Conclusions. We can consider megaprosthesis as a valuable opportunity to restore functionality to patients who are, despite themselves, to deal with highly disabling diseases

Introduction. Up to 2% of total knee arthroplasties (TKA) are still complicated by infection. This leads to dissatisfied patients with poor function, and has far-reaching social and economic consequences. The challenge in these cases is the eradication of infection, the restoration of full function and the prevention of recurrence. We report the outcome of prosthesis sparing early aggressive debridement in the acutely infected TKA. Methods. We studied 29 consecutive patients referred with acutely infected TKA (18 primaries, 11 revisions) which occurred within 6 weeks of the index operation or of haematogenous spread. Microbiology confirmed bacterial colonisation in all cases with 20 early post-operative infections and 9 cases of acute haematogenous spread. All patients underwent aggressive open debridement, a thorough synovectomy and a change of insert. Antibiotics were continued until inflammatory markers and the plasma albumin concentration returned to within normal limits. Results. Three patients required multiple washouts. 8 patients needed a two stage revision. 21 patients returned to their expected functional level without removal of the implants and with no radiographic evidence of prosthetic failure. At a minimum 2 years follow-up, we had a 72% infection control rate. The outcome was significantly better in patients treated in the first 120 hours after presentation. Conclusion. Our data suggests that there is a role for early aggressive open debridement in acute infections after TKA with an excellent chance of prosthesis salvage

Introduction. Up to 2% of total hip arthroplasties (THA) are still complicated by infection. This leads to dissatisfied patients with poor function, and has far-reaching social and economic consequences. The challenge in these cases is the eradication of infection, the restoration of full function and the prevention of recurrence. We report the outcome of early aggressive debridement in the acutely infected THA. Methods. We studied 28 consecutive patients referred with acutely infected THA (18 primaries, 10 revisions) which occurred within 6 weeks of the index operation or of haematogenous spread between 1999 and 2006. Microbiology confirmed bacterial colonisation in all cases with 20 early post-operative infections and 8 cases of acute haematogenous spread. Patients with a cemented THA underwent aggressive open debridement, a thorough synovectomy and exchange of all mobile parts. Uncemented THA were treated as a single stage revision with removal of all implants, aggressive debridement and re-implantation of new prosthesis. Antibiotics were continued in all cases until inflammatory markers and the plasma albumin concentration returned to within normal limits. Results. Ten patients required multiple washouts. 7 patients needed a two stage revision. 21 patients returned to their expected functional level without removal of the implants and with no radiographic evidence of prosthetic failure. At a minimum 2 years follow-up, we had a 75% infection control rate. The outcome was significantly better in patients treated in the first 120 hours after presentation. Discussion and Conclusion. Our data suggests that there is a role for early aggressive open debridement in acute infections after THA with an excellent chance of eradicating infection

The objective of this study was to compare the results of two consecutive series of patients with either intra-medullary uncemented stems (UCS) distal femoral endoprosthetic replacement or the Compress. ®. (CMP) distal femoral implant. Patients were divided into two groups: those who received UCS prosthesis (Group-1: 54 patients) and those who received CMP prosthesis (Group-2: 42 patients).The most frequent diagnosis was osteosarcoma. Age and gender were similar both groups. In Group-1, at a mean follow-up of 144 months, 37 prostheses were still in place. The overall Kaplan-Meier prosthetic survival rates were 79% at five and 62 % at ten years. Most of failures were long term complications. Aseptic loosening was the primary cause of late prosthetic failure. On Cox regression analysis, prosthetic stem diameter under 13mm was a significant negative prognostic factor for prosthetic survival (p=0.016). In Group-2, at a mean follow-up of 84 months, 36 prostheses were still in place. The overall rate of CMP prosthesis survival was 86% at 5 years. All complications were during the first postoperative year, being femoral fracture the main revision cause. The patients who retained the prosthesis had mainly good or excellent MSTS functional results in both groups

Introduction: Up to 2% of total knee arthroplasties (TKA) are still complicated by infection. This leads to dissatisfied patients with poor function, and has far-reaching social and economic consequences. The challenge in these cases is the eradication of infection, the restoration of full function and the prevention of recurrence. We report the outcome of prosthesis sparing early aggressive debridement in the acutely infected TKA. Methods: We studied 29 consecutive patients referred with acutely infected TKA (18 primaries, 11 revisions) which occurred within 6 weeks of the index operation or of haematogenous spread. Microbiology confirmed bacterial colonization in all cases with 20 early postoperative infections and 9 cases of acute haematogenous spread. All patients underwent aggressive open debridement, a thorough synovectomy and a change of insert. Antibiotics were continued until inflammatory markers and the plasma albumin concentration returned to within normal limits. Results: Three patients required multiple washouts. 8 patients needed a two stage revision. 21 patients returned to their expected functional level without removal of the implants and with no radiographic evidence of prosthetic failure. At a minimum 2 years follow-up, we had a 72% infection control rate. The outcome was significantly better in patients treated in the first 120 hours after presentation. Discussion and Conclusion: Our data suggests that there is a role for early aggressive open debridement in acute infections after TKA with an excellent chance of prosthesis salvage

Introduction: The aim of the study was to review the long-term survival and outcome of 49 consecutive endoprosthetic lower limb diaphyseal replacements undertaken for neoplastic conditions. Methods: A retrospective review of all femoral and tibial diaphyseal replacements performed between 1990 and 2009 at our specialist bone and soft tissue tumour unit was performed. Minimum follow-up was one year. Joint sparing prostheses were excluded. Results: 49 femoral (31) and tibial (18) diaphyseal replacements were implanted into 46 patients (31 male, 15 female). Mean age at surgery was 47 years (range 9–79). Surgery was performed for malignancy in 46 cases (97%), of which 41 (89%) were primary bone and soft tissue sarcomas. The predominant pathologies were osteosarcoma (24%), malignant fibrous histiocytoma (14%) and chondrosarcoma (14%). Mean follow-up was 81 months (range 12–221 months). Survival within the follow-up group was 96% at 1 year, 79% at 5 years, and 69% at 10 years. In surviving patients, using revision, recurrence and amputation as endpoints, prosthesis survival was 91% at 1 year, 58% at 5 years, and 33% at 10 years. In total, 13 prostheses underwent revision surgery and there were 3 amputations following diaphyseal replacement. Of these 16 cases, 75% were for aseptic loosening or prosthetic failure, 13% for tumour recurrence, and 13% for infection. Discussion: Lower limb diaphyseal endoprosthetic replacements are a useful surgical treatment method for patients with malignant neoplastic diaphyseal bone lesions requiring excision and reconstruction. This is both limb salvage and joint-sparing reconstructive surgery

Summary Statement. Discovery system produced effective functional improvement in both primary and revision total elbow replacement. The incidence of major complications was in an acceptable range. Introduction. The search for the ideal elbow prosthesis continues as instability and loosening remain the prime reasons for total elbow replacement (TER) failure. The Discovery Elbow System (Biomet) is one of the latest generations of linked prosthesis and has been used in UK since 2003. We report outcome of TER using this system. Methods. A total of 100 TERs (75 primary, 25 revisions) were performed between 2003 and 2010. The main primary underlying pathologies for TER were advanced rheumatoid arthritis (N=58), osteoarthritis (N=35), acute fractures (N=7). There were 60 female and 40 male patients with an average age of 62 years. The outcome assessment included pain, patient satisfaction, Liverpool Elbow Score (LES), range of movement, and imaging during a mean follow-up period of 48.5 months. Major complications are also reported. Results. For the whole patient group (primary + revision), the LES was significantly (p<0.001) improved from 3.79+/−1.71 to 6.36+/−1.85There were significant improvements in elbow flexion from 100°+/−24 to 118°+17, supination from 38°+/−26 to 50°+/−25 and pronation from 48°+/−22 to 61°+/−21. Mean improvement in flexion-extension and pronation-supination arc was 20° and 25°, respectively. 64% of cases were completely pain-free and at the final follow-up (compared to 7% preoperatively). Only 6% of patients scored “Not Satisfied” at the final follow-up. LES improvement was significantly higher in the primary TER compared to revision TER (p<0.05). Imaging reviewed for 60 cases showed loosening in 4% of patients. Other main complications included deep infection (N=2), ulnar neuropathy (N=3), pre-prosthetic fracture (N=2), and prosthetic failure (N=1). Discussion. TER using the Discovery Elbow System is an effective arthroplasty in terms of functional improvement, pain relief and range of motion in both primary and revision patients. TER resulted in no/mild pain in 78% of cases. Patients undergoing Acclaim, Souter-Strathclyde, GSB III, and Coonrad-Morrey TER have been reported to have no/mild pain in 64%, 67%, 50–92% and 60–100% of cases, respectively. A 20° improvement in flexion-extension arc is comparable to that of Acclaim (23°), Souter-Strathclyde (15°), GSBIII (19–33°), and Coonrad-Morrey (17–26°) TER. An improvement of 25° in pronation-supination arc in our series is also comparable to that of 21–28° reported the Coonrad-Morrey and 27–33° for Discovery prostheses. An infection rate of 2% is lower than several other reports for GSB III TER (7–11%) and Coonrad-Morrey (6–8%). The incidence of persistent ulnar neuropathy (3%) was lower compared to GSBIII TER (11–14%), Coonrad-Morrey (12–26%), and Acclaim (8%)

Only 0.8% of arthroplasties registered on the National Joint Registry in 2006 are patello-femoral. The Leicester patello-femoral replacement (Corin) has been in use for over 10 years with satisfactory initial results. The indication for use is isolated patello-femoral osteoarthritis with the theoretical benefits of bone preservation, maintenance of normal knee mechanics and easy revision. The implant was only available in one size and the femoral component was uncemented. We reviewed 49 patients managed with this prosthesis with a median follow up of 10 years (range 4-16). The mean age of the patients at time of surgery was 64. 62 arthroplasties were performed.51 were in females and 11 in males giving a 5:1 ratio. Thirteen patients had bilateral procedures. Thirty-nine revisions (62.9%) were performed for progressive tibio-femoral arthritis or prosthetic failure. Mean time to revision was 5 years 3 months. The knees were revised to total knee replacements without the need for stems, wedges or constraint. The unrevised knees had a mean survivorship of 8 years 6 months with a range of 4-14 years. The mean Oxford score for these surviving implants was 22.5. Results of other implants from the literature included the Avon prosthesis with 80% satisfaction rate at 5 years and the Lubinus with 45% satisfaction rate at 7.5 years. The Leicester device showed a pattern of progressive failure with up to 40% revision at 5 years. However those with surviving implants were reasonably happy as shown by the Oxford scores. We concluded that patello-femoral replacement has a role though this is not as well defined as TKR or even UKR. We posed the question as to whether these results were due to poor patient selection or design failings of the Leicester prosthesis. This prosthesis has been successful at reducing pain and improving function and may have been more successful with more sizes of implant, better instrumentation and more rigid patient selection

Purpose: Implant retrieval analysis provides valuable information to researchers, clinicians and manufactures about the in vivo wear characteristics. Wear analysis can quantify visible damage on retrieved UHMWPE bearing surfaces used in total knee arthroplasty (TKA). Various researchers have developed wear scores to help provide insight into the modes of prosthetic failure. Four scoring methods are compared in order to determine their inter-rater reliability. Method: A cohort of 60 retrieved G2, Smith & Nephew/Richards, TKA implants were analyzed by two observers using four scoring techniques. The scoring methods used had been developed by Hood, Wasielewski, Currier, and Brandt. The intraclass correlation coefficient (ICC) was used in assessing the inter-rater reliability. Results: The ICC demonstrated significant correlation between raters (P< 0.05). Hood’s method produced a correlation of 0.89, Wasielewski’s method 0.83, Currier’s method 0.58, and Brandt’s method 0.82. All but Currier’s method had excellent correlation between raters. Conclusion: The analysis techniques for articular surface wear for total knee bearings by Hood, Brandt, and Wasielewski showed excellent inter rater reliability; however currier’s method was only fair. One common issue among all these methods is that the scoring systems do not identify or assign differentiating weights to clinically relevant wear modalities to capture inferior implants designs. A new wear analysis technique that is efficient and assigns clinical severity weights to wear modes in TKA bearings should be investigated

Leukocyte esterase (LE) has shown to be an accurate marker of prosthetic joint infections and has been proposed as an alternative to frozen section (FS) for intra-operative diagnosis. In this study, intra-operative determination of LE was compared with FS for the diagnosis of periprosthetic hip infections. One hundred and nineteen patients undergoing hip revision surgery due to prosthetic joint failure from June 2015 to December 2017 were considered. Joint fluids were collected before the arthrotomy for determination of LE which was performed by using enzymatic colorimetric strips. Four to six samples were stained with hematoxylin eosin for FS and considered suggestive for infection when at least 5 polymorphonuclear leukocytes in 5 fields at high power fields were found. Sensitivity and specificity of LE were 100% and 93.8 %, respectively. The positive predictive value was 79.3 %, while the negative predictive value was 100%. Time from collection to response was 20.1 ± 4.4 minutes. Sensitivity and specificity of FS were 83.3 % and 92.1 %, respectively. The positive and negative predictive values were 84.6 % and 97.1%. Time from sample collection response was 27.2 ± 6.9 minutes. LE showed a higher sensitivity and a slightly lower specificity and the same diagnostic accuracy of intraoperative FS. The faster turnaround time (about 20 minutes from receiving of sample by the laboratory), its ease of use and the low costs make this test a valuable alternative to frozen sections and is going to replace FS in our clinical practice

Purpose. of this study is to analyze the results of a modular reconstructive tumor prosthesis for the lower limb (GMRS. (r). ) with a comparative statistical analysis of primary and secondary implants. Material and methods. From October 2003 to September 2007 at Rizzoli 161 GMRS. (r). prostheses were implanted, most after resection of osteosarcoma (94 cases, 58%). It is a modular system with a rotating hinge mechanism for the knee, cemented and uncemented stems, in titanium and chromium-cobalt-molybdenum, curved and straight-fluted, with or without hydroxyapatite coating. Moreover adaptors are available to revise HMRS. (r). implants. This series includes 88 males and 73 females ranging in age from 9 to 80 years. Sites of reconstruction were 109 distal femurs, 19 proximal femurs, 1 total femur and 32 proximal tibias. There were 149 oncologic and 12 non oncologic diagnoses, including 96 primary reconstructions and 65 revisions after failure of previous implant. A retrospective analysis of imaging and complications was performed and functional results assessed according to MSTS system. Statistical analysis with Kaplan-Meier curves was used to study implant survival. Results. At a mean follow up of 2 yrs. 106 patients are continuously NED, 31 are NED after treatment of one or more local recurrence or metastasis, 7 AWD, 5 DWD. There were 10 major complications: 8 infections (4,7%) (5 in primary and 3 in secondary implants, 2 previously infected) and 2 aseptic loosening (1,2%) (1 each). There were 9 minor complications (4 wound sloughs, 1 stiff joint, 3 disrupted extensor apparatus,1 patellar instability) requiring revision. Comparative statistical analysis of primary and secondary implants survival at major complications shows no statistically significant difference. Functional results were good or excellent in 95% of the evaluated patients, without any poor. Conclusions. Middle term results are promising: good function, very low incidence of major complications, no breakage of implant components. This prosthetic reconstruction is indicated in oncological cases as well as in selected in some non oncological settings, such as challenging revisions of prosthetic failures with massive bone loss or post-radiation non unions or allografts failures. Although a higher incidence of complications was expected in secondary implants, statistical analysis shows similar survival