Aims

Monocyte-lymphocyte ratio (MLR) or neutrophil-lymphocyte ratio (NLR) are useful for diagnosing periprosthetic joint infection (PJI), but their diagnostic values are unclear for screening fixation-related infection (FRI) in patients for whom conversion total hip arthroplasty (THA) is planned after failed internal fixation for femoral neck fracture.

Background. An increased incidence of periprosthetic osteolysis, resulting in loss of biologic fixation, has been recently reported in contemporary THAs with low-carbide metal-on-metal compared to metal-on-polyethylene couple bearings. A hypersensitivity reaction due to Co and Cr debris is reported as a potential cause for failure of THAs with high-carbide bearings, but there are no evidence-based data for this reaction in low-carbide metal-on-metal bearings. Questions/purposes. We investigated whether there were differences in immunologic hypersensitivity reactions in retrievals from revised THAs with COP versus MOM bearing couples. Patients and Methods. We compared newly formed capsule and periprosthetic interface membranes retrieved from revision surgery due to aseptic failure in 20 patients with low-carbide bearings and 13 patients with ceramic-on-polyethylene bearings. For control tissue we obtained samples from the hip capsule during the primary THA implantation in 13 patients with low-carbide bearings and seven with ceramic-on-polyethylene. We examined the tissues with conventional histologic and immunohistochemical methods. Results. Compared to the controls and the tissue from patients with ceramic-on-polyethylene bearings, the tissues from patients with low-carbide metal-on-metal bearings were associated with (1) extensive necrosis and fibrin exudation in the newly formed hip capsule and (2) diffuse and perivascular lymphocytic infiltration of a higher degree than in the ceramic-on-polyethylene hips in conventional histologic examination and (3) more T than B cells. Conclusions. The conventional histologic and immunohistochemical findings in tissues retrieved from failed THAs with low-carbide metal-on-metal bearings are consistent with a link between hypersensitivity and osteolysis with low-carbide bearing couple THA

Introduction. Total knee replacement has been well-established form of treatment both for osteoarthritis and inflammatory arthritis. Both cemented and uncemented TKR have been used successfully. Since 1977 low contact stress (LCS) mobile bearing knee replacement has been in extensive use. Most of the intermediate and long term results reported are in osteoarthritis1–7. Though there are several studies reporting short term performance of TKR in rheumatoid arthritis8–19 there have been rare reports31 of intermediate to long-term performance of LCS uncemented TKR in rheumatoid arthritis. Methods. Retrospective, non-randomised and consecutive study. Case notes and radiological assessment done. Kaplan meyer survival analysis used. Radiological assessment between initial and final xrays done using T test statistics. Assessement done by two independent observer. Results. 108 knees in 67 patients are collected. 21 patients with 36 knees have died. Only 65 knees in 42 patients had both case notes and xrays which are included in this study. Of this 11 knees in 7 patients were dead. All 65 knees in 42 patients are sero-positive rheumatoid arthritis. Pre-operative bone loss was seen only in 4 knees. Bone loss was in the medial side in 3 knees (4,5 and 8mm respectively) and lateral in 1 knee (1 cm). None of these bone loss needed bone grafting or any special procedures. There was no subsidence in any of the 65 knees. Survival of uncemented LCS TKR in inflammatory arthritis patients is 100%. Aseptic failure is 0%. No infective failure. There is no significant change in the implant position. This is the longest follow for uncemented TKR in inflammatory arthritis ever reported in the literature. Conclusion and Discussion. In conclusion, our study has uniformity, as a single surgeon performed/supervised with senior trainees all the operations and all patients received the same level of post-operative care. Survival of LCS uncemented TKR in inflammatory arthritis patients is 100% up to 15years. This is the longest follow up in this patient population ever reported in the literature. Our study shows excellent survival and comparable to other cemented TKRs in this patient population reported in the literature. This study proves contrary to the general belief that uncemented TKR do poor in inflammatory arthritis due to osteoporotic bone

Understanding the cause of failure of total knee arthroplasties (TKA) is essential in guiding clinical decision making and adjusting treatment concepts for revision surgery. The purpose of the study was to determine current mechanisms of failure of TKA and to describe changes and trends in revision surgery over the last 10 years. A retrospective review was done on all patients who had revision total knee arthroplasty during a 10-year period (2000–2009) at one institution. The preoperative evaluation in conjunction with the intraoperative findings was used to determine causes of failure. All procedures were categorizes as Sharkey et al. described previously. The data was analyzed regarding the cause of failure and displaying the incidence and trends over the last 10 years. 1225 surgeries were done in the time period with a steady increase of procedures per year (34 procedures in 2000 to 196 in 2009). The most common cause of revision TKA was aseptic failure in 65% and septic failure in 31% of the reviewed cases. However, we could observe a steady proportional increase of the septic classified revisions over the time. Both categories could be subdivided to specific causes of failure including aseptic loosening (24%), anterior knee pain (20%), instability (6,4%), arthrofibrosis (4,9%), PE wear (3,6%), malpositioning/malrotation (2,7%) periprosthetic fracture (2,0%) and other (4,6%), or in early (12,9%), late (15,4%) or low-grade infection (3,3%), respectively. Complementary to the classification Sharkey et al. described in 2002 we identified new subcategories of failure: malrotation (since 2003), Low-Grade-Infection (since 2006), allergic failure/loosening (since 2006), Mid-Flexion-Instability (since 2007), soft tissue impingement (since 2009). The incidence of the classic aseptic loosening due to PE wear shows a clear decrease in the last 10 years whereas we could observe an increase of the new diagnosis of instability, malrotation or low-grade-infection as determined cause of failure. The detailed analysis of the failure mechanism in total knee arthroplasty is important to understand the clinical problem and to adjust treatment strategies. We were able to complement present classifications and give a first overview on the incidence for specific causes of failure. Our data shows changes in the indication for surgery over the time and compared to the collective of Sharkey et al. from 1997–2000. This might be due to new diagnostic methods and better implant materials as well as to a generally increased awareness of the specific mechanism of TKA failure

Over the last few decades, the All-Poly Monoblock Tibia has been relegated to a minimum use in the major healthcare systems of the western world. The main reason for this has been the perception that this tibial component is inferior in its ability to withstand stresses. This perception originated and subsequently gained ground, due to certain historical reasons, leading to the widespread use of the modular metal-backed tibial component despite a higher cost. The recent economic downturn has enforced even the rich western healthcare systems to look for cost-effective solutions. The author works in India, where the society is still highly price-sensitive and takes value for money very seriously. Further, the routine ADL of the Indian population requires them to adopt high flexion postures such as cross-legged sitting and squatting. The author has used the All-Poly Tibia extensively, which is the most economical of tibial components. Further, he has developed a surgical technique which has resulted in his patients achieving high flexion (greater than 135 degrees) in more than 75% cases. This paper presents the 10 year results of a series of 500 cases of Primary TKR in which the All-Poly Monoblock Tibia had been used. All the patients had cross-legged sitting activity as part of their ADL, thus presumably generating significant pressures on the joint surfaces. Of the original 500 cases, we could follow up 434 cases. We report a 96% survival rate of the implant in this series. There was not a single aseptic plastic failure. The revisions required were due to infection, peri-prosthetic fracture, and instability. The message being conveyed in this paper is that the All-Poly Tibia is a very cost-effective solution in routine Primary TKRs, and is able to deliver excellent long-term results even in high stress situations like cross-legged sitting activity. It would offer a huge cost savings to the healthcare system if the Orthopaedic Surgeons start using this implant more frequently